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Journal of Composites Science
Number of Followers: 4  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2504-477X
Published by MDPI Homepage  [258 journals]
  • J. Compos. Sci., Vol. 7, Pages 90: Waste Iron Filings to Improve the
           Mechanical and Electrical Properties of Glass Fiber-Reinforced Epoxy
           (GFRE) Composites

    • Authors: Hatem Abushammala, Jia Mao
      First page: 90
      Abstract: Several studies have been conducted to improve the mechanical and other value-added properties of glass fiber-reinforced epoxy (GFRE) composites by the addition of different fillers. In this work, waste iron filings (WIFs) obtained from the steel industry were incorporated into GFRE composite samples in varying amounts of up to 50% (%w) to improve their mechanical and electrical properties. The results showed that, with increasing WIF loading from 0 w% to 50 w%, the resultant composite density gradually increased from 1.4 to 2.1 g/cm3. Surface hardness, Young’s modulus, and tensile strength also increased significantly with the addition of up to 9 w% of WIF followed by a significant drop with more WIF addition due to agglomeration. Overall, Young’s modulus of the GFRE samples with any WIF content was higher than that of the GFRE composite with no WIF. The elongation at break results showed that the GFRE samples were less ductile upon WIF addition, which decreased from 2% to 0.6% upon loading the composite with 50% WIF. In terms of electrical conductivity, the GFRE samples with WIF content of 15% or more were electrically conductive and their electrical conductivity increased with WIF content. It was clear that more WIF was needed to establish a percolated network in the GFRE composites to render them conductive. The electrical conductivity of the GFRE samples containing 15% WIFs was around 2.9 kS/m and increased to 35 kS/m upon the addition of 50% WIFs. These novel electrically conductive GFRE composites could be promising for structural dynamic monitoring systems in the construction industry. They also support the efforts for the utilization of waste materials towards a circular economy.
      Citation: Journal of Composites Science
      PubDate: 2023-02-21
      DOI: 10.3390/jcs7030090
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 91: Individual and Combined Effects of
           Reinforcements on Fractured Surface of Artificially Aged Al6061 Hybrid

    • Authors: Manjunath Shettar, Sathyashankara Sharma, Gowrishankar M C, Vishwanatha H M, Rakesh Ranjan, Srinivas Doddapaneni
      First page: 91
      Abstract: The present work mainly focuses on a comparative study of the individual and combined effect of reinforcements on tensile strength and fracture surface analysis of Al6061 alloy and its composites during artificial aging. SiC and B4C are the two reinforcements used in the present work for the preparation of Al6061 composites by the stir casting process, and the reinforcement percentage from 2, 4, and 6 wt.% varied. Both Al6061 alloy and its composites are solution-treated at 558 °C/2 h and artificially aged at 100 and 200 °C for different time intervals to achieve peak aging. The results show substantial improvement in ultimate tensile strength during low temperature aging at 100 °C. Approximately 80–110% increase in UTS value is observed in both individual and hybrid composites compared to Al6061 alloy. The mechanism of failure governing the tensile strength for both alloy and its composites is thoroughly analyzed and discussed using a scanning electron microscope. The morphology of crack propagation is also studied to determine the mechanism of failure. Al6061 alloy shows ductile failure due to coarser dimples. Al6061-SiC composites show particle-matrix interface cracking and shear failure. Al6061-B4C composites show elongated dimple rupture mode of failure, whereas Al6061-SiC + B4C hybrid composites fail due to nucleation growth and mixed fracture mode.
      Citation: Journal of Composites Science
      PubDate: 2023-03-01
      DOI: 10.3390/jcs7030091
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 92: Performance of High-Strength Concrete
           with the Effects of Seashell Powder as Binder Replacement and Waste Glass
           Powder as Fine Aggregate

    • Authors: Prathibha P. Shetty, Asha U. Rao, B. H. V. Pai, Muralidhar V. Kamath
      First page: 92
      Abstract: Seashell powder (SSP) is a waste from aquatic life that is generally available near the coastal region. Due to its high calcium content, SSP can be utilized as a supplementary cementitious binder. SSP can be used as a sustainable binder to replace ordinary Portland cement (OPC) and significantly reduce the carbon footprint. The present study investigates the effects of SSP and waste glass powder (WGP) on the fresh, mechanical, and microstructure properties of high-strength concrete (HSC). The SSP utilized in this research was varied, with 5%, 10%, and 15% cement replacement levels. The impact of WGP was also observed with two replacement levels, 5% and 10%, replacing natural sand. The slump flow of all the HSC mixes varied between 700 and 785 mm. A maximum compressive strength of 112.91 MPa was found for the C75SSP5 mix at 56 days. The split tensile strength values of all the HSC mixes were found in a range from 5.45 to 10.56 MPa. The modulus of elasticity values of all the HSC mixes were found to lie between 40.2 and 46.8 GPa. The lowest water absorption was observed in the mix containing 5% SSP. The SEM image of the HSC with increased SSP showed that it was denser and had fewer unreacted particles. XRD and EDS showed the presence of various gels, such as calcium silicate hydrates (CSHs), ettringite, calcium hydroxide (CH), and calcium carbonate (CC). The predicted equations for its split tensile strength, flexural strength, modulus of elasticity, and water absorption were also carried out in the present research.
      Citation: Journal of Composites Science
      PubDate: 2023-03-02
      DOI: 10.3390/jcs7030092
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 93: Performance Evaluation of an Improved
           ANFIS Approach Using Different Algorithms to Predict the Bonding Strength
           of Glulam Adhered by Modified Soy Protein–MUF Resin Adhesive

    • Authors: Morteza Nazerian, Fatemeh Naderi, Antonios N. Papadopoulos
      First page: 93
      Abstract: Despite studies on the potential replacement of synthetic resins by bio-based adhesives such as proteins in recent years, there is still no reliable method for estimating the strength of wood products made using the combined parameters in the literature. This limitation is due to the nonlinear relationship between strength and the combined components. In the present research, the application of artificial intelligence techniques was studied to predict the bonding strength of glulam adhered by protein containing different ratios of MUF (melamine–urea–formaldehyde) resin with different F-to-U/M molar ratios at different press temperatures. For this purpose, the ANFIS artificial intelligence model was used as basic mode or combined with ant colony optimization (ACOR), particle swarm optimization (PSO), differential evaluation (DE) and genetic algorithms (GA) to develop an optimal trained model to predict the bonding strength of glulam based on experimental results. Comparison of the obtained results with the experimental results showed the ability of the above methods to estimate the bonding strength of glulam in a reliable manner. Although the basic ANFIS alone and in combination with other algorithms was not able to achieve an ideal performance prediction to estimate bonding strength, the combination of GA and ANFIS offered an excellent ability compared to the combination of other algorithms combined with ANFIS. Hence, the developed ANFIS-GA model is introduced as the best prediction technique to solve bonding strength problems of laminated products. In addition, using the developed optimal model, a precise attempt was made to show the nature of the parameters used to produce glulam and determine the optimum limit.
      Citation: Journal of Composites Science
      PubDate: 2023-03-03
      DOI: 10.3390/jcs7030093
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 94: Development of Chitosan/Whey Protein
           Hydrolysate Composite Films for Food Packaging Application

    • Authors: Sawsan A. Al-Hilifi, Orass T. Al-Ibresam, Raqad R. Al-Hatim, Rawdah M. Al-Ali, Namrata Maslekar, Yin Yao, Vipul Agarwal
      First page: 94
      Abstract: There is a significant drive towards the development of edible biocompatible films for food packaging application due to the environmental and health impacts of synthetic packaging materials. This has inspired the exploration of biodegradable natural polymers as packaging materials. To address the instant water disintegration of most natural polymers, polymers with conditional water solubility, such as chitosan (needing acidic conditions for dissolution in water), have gained significant research attention. To this end, chitosan has been blended with different natural proteins, including whey protein isolates, to prepare edible food films. However, consumption of whey protein isolates in their natural form has been proposed in the literature to prolong processing (digestion) time upon consumption. To circumvent this limitation, here we report the development of chitosan/whey protein hydrolysate-based edible films with additional antioxidant properties. The developed films revealed that the inclusion of whey protein hydrolysate improved physicochemical properties and mechanical strength of the films with tensile strength of 26.3 MPa at 1 wt% WPH loading compared to 10.9 MPa in control neat chitosan films (0 wt% WPH). Furthermore, chitosan/whey protein hydrolysate exhibited a significant (whey protein hydrolysate) dose-dependent antioxidant response with a maximum value of 83% DPPH in chitosan/WPH (1 wt%) films assessed using two different antioxidant assays. Based on the results from this study, we envisage the exploration of whey protein hydrolysate-based films for commercial food packaging application in future.
      Citation: Journal of Composites Science
      PubDate: 2023-03-03
      DOI: 10.3390/jcs7030094
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 95: Design and Fabrication of Aerogel
           Composites for Oil Water Separation and Spilled Oil Cleaning

    • Authors: Yong X. Gan
      First page: 95
      Abstract: Aerogel composites are multicomponent highly porous materials with air as the major dispersed phase. There are many kinds of aerogel composites including synthetic and natural aerogel composites. Aerogel composites have found wide applications in sorption, thermal insulation, vibration damping, and noise control. This mini review focuses on the aerogel composites with oil water separation function for spilled oil cleaning. The design and fabrication of various aerogel composites for oil cleaning are emphasized. The commonly used technologies including in-situ reaction, sol–gel spinning, templating, and self-assembling are introduced. The microstructure control through directional freeze casting, bio-inspired approach, coating, etc., are discussed.
      Citation: Journal of Composites Science
      PubDate: 2023-03-03
      DOI: 10.3390/jcs7030095
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 96: Nanomodified Basalt Fiber Cement
           Composite with Bottom Ash

    • Authors: Roman Fediuk, Natalia Makarova, Andrey Kozin, Maksim Lomov, Victoria Petropavlovskaya, Tatiana Novichenkova, Xiao Wenxu, Mikhail Sulman, Kirill Petropavlovskii
      First page: 96
      Abstract: Directed control of the process of structure formation of a cement composite from modern positions must be carried out taking into account the synergistic effect of its components. In particular, the cement composite, when applied with pozzolanic additives and fiber reinforcement, is transformed into a more complex material with excellent performance. The aim of the article is to study the combined action of nanomodified basalt fiber (NBF) and bottom ash (BA) as structural elements of concrete. To achieve this aim, a number of tasks were performed, including the development of nanomodified-basalt-fiber–bottom-ash–cement concretes, as well as the study of their fresh, physical and mechanical properties (flowability, average density, compressive and flexural strength, elastic modulus and crack resistance) and durability characteristics (water, frost and abrasion resistance). A series of nanomodified basalt-fiber-reinforced concretes (from 0 to 7 wt.% NBF) were developed, in which the economical Portland cement CEM I 32.5 N was replaced by up to 45 wt.% mechanically activated bottom ash residue (400 m2/kg). An economical superplasticizer with a high water-reducing capacity (35%) made it possible to achieve uniform flowability of the mixes (slump 20–22 cm and slump flow 45–52 cm). The combined effect of BA and NBF provides control over the structure formation of cement materials, which ensures the redistribution of internal stresses from shrinkage deformations throughout the entire volume of the composite; under loading, the process of crack formation slows down, the stress concentration near structural defects decreases, and stresses are redistributed in the microstructure of the cement composite between its components. Perfect values of mechanical properties (compressive strength up to 59.2 MPa, flexural strength up to 17.8 MPa, elastic modulus up to 52.6 GPa, critical stress intensity factor 0.507 MPa m0.5) are explained by the complex action of the ash residue and nanomodified basalt fibers. A mix with 30 wt.% BA and 5 wt.% NBF is characterized by water resistance grade W18, frost resistance class F400 and abrasion resistance 0.59 g/cm2, which confirms the high wear resistance of the developed materials.
      Citation: Journal of Composites Science
      PubDate: 2023-03-03
      DOI: 10.3390/jcs7030096
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 97: Magnetic Susceptibility of a
           Nanocomposite Based on an Opal Matrix with Yb2Ti2O7 Particles

    • Authors: Anatoly B. Rinkevich, Olga V. Nemytova, Dmitry V. Perov
      First page: 97
      Abstract: The DC and AC magnetic susceptibilities of an opal matrix-based nanocomposite with pyrochlore-structured ytterbium titanate particles up to 60 nm in size have been studied in the range of magnetic fields up to 30 kOe. The measurements were performed at temperatures from 2 to 200 K. The temperature dependence of the nanocomposite Yb2Ti2O7 has been found to deviate significantly from the Curie–Weiss law. From the frequency dependence of the AC susceptibility measured in the range from 10 Hz to 10 kHz, the spin relaxation times have been determined, and two relaxation times have been found to be required for the description of the frequency dependence of the susceptibility. The field dependence of the AC susceptibility has been measured. This dependence is proved to be described by the modified Cole–Cole formula. The characteristic fields of the magnetic field dependence of the real part of the susceptibility are determined, the value of the characteristic field being found to increase with increasing temperatures.
      Citation: Journal of Composites Science
      PubDate: 2023-03-03
      DOI: 10.3390/jcs7030097
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 98: Fabrication and Characterization of
           Hollow Polysiloxane Microsphere Polymer Matrix Composites with Improved
           Energy Absorption

    • Authors: Sofia Gabriela Gomez, Andrea Irigoyen, Stephanie Gonzalez, Kevin Estala-Rodriguez, Evgeny Shafirovich, Md Sahid Hassan, Saqlain Zaman, Yirong Lin
      First page: 98
      Abstract: Hollow polymer microspheres with superior elastic properties, high thermal stability, and energy absorbance capabilities are essential in many applications where shock and vibration need to be mitigated, such as in civil, medical, and defense industries. In this paper, the synthesis, fabrication, and characterization of hollow thermoset microspheres for syntactic polymer foam were studied. The hollow polymer microspheres (HPMs) were made by developing core–shell composites and thermally removing the polystyrene core to yield a polysiloxane shell. The HPMs were embedded into a polydimethylsiloxane (PDMS) matrix to form a polymer syntactic foam. The mechanical energy absorption characteristic of polymer syntactic foams was measured by cyclic uniaxial compression testing following ASTM 575. The engineered compression response was demonstrated by fabricating and testing syntactic foams with different porosities, ranging from a 50 vol% to 70 vol% of HPMs. Through scanning electron microscopy (SEM), we observed that the HPM contributes to the energy absorption of the syntactic foam. Moreover, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) determined the necessity of a profound study to understand the effects of varying HPM synthesis parameters, as well as the syntactic foam fabrication methods. It was shown that the compressive modulus and toughness can be increased by 20% using a 70 vol% of porosity with synthesized HPM syntactic foams over bulk PDMS. We also found that the energy absorbed increased by 540% when using a 50 vol% of porosity with fabricated HPM-PDMS syntactic foams.
      Citation: Journal of Composites Science
      PubDate: 2023-03-04
      DOI: 10.3390/jcs7030098
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 99: Recycled Glass Polypropylene Composites
           from Transportation Manufacturing Waste

    • Authors: Uday Vaidya, Sanjita Wasti, Halil Tekinalp, Ahmed Arabi Hassen, Soydan Ozcan
      First page: 99
      Abstract: In recent years there has been growing interest in developing recycling technologies for composites manufacturing scrap, process waste and end-of-life parts. The focus of this work was to establish processing routes and mechanical property bounds for glass-polypropylene (PP-GF) scrap from the production of parts for truck trailers, automobiles, and rail cars. This study considered PP-GF scrap and demonstrated extrusion-compression molding (ECM) as a viable route for the closed-loop manufacture of composite parts. The results were promising in terms of the strength and modulus retention of the PP-GF recyclate. The tensile strength and modulus was the highest for 50% and 66% recycled content, compared with 100% and 83% recycle content. The flexural strength and modulus of the 100% and 83% recycled compositions was higher than the 66% and 50% recycled content, respectively. The impact energy absorption of the PP-GF recyclate at at all fiber loadings was superior in absorbing energy compared with the incumbent (benchmark) plywood. This work is useful to designers seeking to incorporate recycled materials in their products.
      Citation: Journal of Composites Science
      PubDate: 2023-03-06
      DOI: 10.3390/jcs7030099
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 100: Moisture Content and Mechanical
           Properties of Bio-Waste Pellets for Fuel and/or Water Remediation

    • Authors: Yuriy A. Anisimov, Bernd G. K. Steiger, Duncan E. Cree, Lee D. Wilson
      First page: 100
      Abstract: The current research is focused on the mutual comparison (mechanical properties, response to humidity) of agro-waste composite materials. The purpose of this work is directed at the valorization of agro-waste biomass products and to investigate their mechanical stability for transport or other applications (in dry and wet states). Three different types of agro-waste (oat hull (Oh), torrefied wheat straw (S), and spent coffee grounds (SCG)) were blended with kaolinite (K) and chitosan (CHT) at variable weight ratios to yield ternary composites. Mechanical properties were represented by measuring hardness (in compression mode) and elastic modulus (under tension mode). Young’s (elastic) modulus was measured both for dried and hydrated samples. The pelletized materials were prepared in two forms: crosslinked (CL) with epichlorohydrin and non-crosslinked (NCL). The hardness of the Oh pellets was poor (75 N) and decreased by four times with greater agro-waste content, while crosslinking affected the hardness only slightly. S pellets had the highest level of hardness at 40% agro-waste content (160 N), with a concomitant decrease to 120 N upon crosslinking. SCG pellets had the least change in hardness for both CL and NCL specimens (105–120 N). The trends of Young’s modulus were similar to hardness. Hydration caused the elastic modulus to decrease ca. 100-fold. In general, S and SCG composites exhibit the greatest hardness and Young’s modulus compared to Oh composites (CL or NCL) in their dry state.
      Citation: Journal of Composites Science
      PubDate: 2023-03-06
      DOI: 10.3390/jcs7030100
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 101: Effect of Roller Pressure and Base
           Prepreg Layer on Tensile and Flexural Properties of CFRP Laminates
           Fabricated Using Automated Fiber Placement

    • Authors: Eldho Mathew, Sunil Chandrakant Joshi
      First page: 101
      Abstract: Composites can be manufactured in numerous ways. Among the available methods, Automated Fiber Placement (AFP) is the most advanced and latest technology utilized by companies for aerospace and other projects. Although it offers many benefits, it has unique manufacturing challenges and quality issues. The presence of tow placement defects such as tow gaps, tow overlaps, twisted tows, incomplete tows, and missing tows in the AFP process are causes for concern as these lead to a decrease in the mechanical performance of the fabricated parts. Although it is not possible to completely avoid the occurrence of defects, optimizing key process parameters is a possible way to minimize them. Roller pressure is one such parameter. If it is too high, it can lead to wider and thinner tows and if it is too low, the towpreg may not stick properly to the substrate and hence, not conform to curvatures. In this work, test layups of different configurations using carbon (T700SC-24K-50C) towpreg with epoxy (UF 3376-100) as the matrix system were prepared at different compaction roller pressures (2 bar, 3.5 bar, and 5 bar), with and without the presence of base prepreg layers. Tensile and bending tests were respectively carried out according to ASTM D3039 and ASTM D7264 to study the effects of these process parameters on the layup defects. From the test results, it is found that using a compaction roller pressure of 3.5 bar and a base prepreg layer of the same material as the towpreg, leads to minimum defects, and hence, to the best tensile and bending properties.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030101
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 102: State-Of-The-Art of Sandwich Composite
           Structures: Manufacturing—to—High Performance Applications

    • Authors: Ayesha Kausar, Ishaq Ahmad, Sobia A. Rakha, M. H. Eisa, Abdoulaye Diallo
      First page: 102
      Abstract: This cutting-edge review highlights the fundamentals, design, and manufacturing strategies used for sandwich composites. Sandwich composite structures have the advantages of light weight, high strength, impact resistance, stability, and other superior features for advanced applications. In this regard, different core materials have been used in the sandwich composite structures, such as cellular polymer foam, metallic foam, honeycomb, balsa, tubular, and other core geometries. Among these, honeycomb sandwich composite materials have been effectively applied in space engineering, marine engineering, and construction applications. The foremost manufacturing techniques used for sandwiched composite structures include hand lay-up, press method, prepreg method, vacuum bagging/autoclave, vacuum assisted resin infusion, resin transfer molding, compression molding, pultrusion, three-dimensional (3D) printing, four-dimensional (4D) printing, etc. In advanced composite manufacturing, autoclave processes have been the method of choice for the aerospace industry due to less delamination between plies and easy control of thickness dimensions. Moreover, machining processes used for sandwich composites are discussed in this article. In addition to aerospace, the high-performance significance of sandwiched composite structures is covered mainly in relation to automobile engineering and energy absorption applications. The structure-, fabrication-, and application-related challenges and probable future research directions are also discussed in this article.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030102
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 103: Chitosan-Biopolymer-Entrapped
           Activated Charcoal for Adsorption of Reactive Orange Dye from Aqueous
           Phase and CO2 from Gaseous Phase

    • Authors: Pradip Nandanwar, Ravin Jugade, Vaishnavi Gomase, Anita Shekhawat, Apurva Bambal, Dhandayutham Saravanan, Sadanand Pandey
      First page: 103
      Abstract: Polymers have been proven to be an interesting class of adsorbents applied in water treatment. Biopolymers are of special interest due to their unique properties such as biocompatibility, biodegradability, and reusability. This work reports a composite formed by a chitosan biopolymer and activated charcoal using sodium citrate as a crosslinking agent. The chitosan–citrate-activated charcoal composite (CCA) was characterized using FT–IR, SEM, EDAX, XRD, TGA–DTA and BET surface area analysis. The material was found to be microporous in nature with a surface area of 165.83 m2/g that led to high adsorption capacities toward both the targeted pollutants. In an aqueous phase, the dye adsorption studies were carried out with reactive orange 16 (R-16) dye, while in a gaseous phase, CO2 adsorption capacity was evaluated. Under optimum solution conditions, maximum R-16 dye removal capacity was found to be 34.62 mg g−1, while in the gas phase the CO2 adsorption capacity was found to be 13.15 cm3g−1. Intrinsic microporosity of CCA resulted in an enhanced capture capacity for R-16 dye and carbon dioxide in the respective phases. Material sustainability studies were carried out to evaluate various sustainability parameters.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030103
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 104: Engineering Ligament Scaffolds Based
           on PLA/Graphite Nanoplatelet Composites by 3D Printing or Braiding

    • Authors: Magda Silva, Isabel Pinho, Hugo Gonçalves, Ana C. Vale, Maria C. Paiva, Natália M. Alves, José A. Covas
      First page: 104
      Abstract: The development of scaffolds for tissue-engineered growth of the anterior cruciate ligament (ACL) is a promising approach to overcome the limitations of current solutions. This work proposes novel biodegradable and biocompatible scaffolds matching the mechanical characteristics of the native human ligament. Poly(L-lactic acid) (PLA) scaffolds reinforced with graphite nano-platelets (PLA+EG) as received, chemically functionalized (PLA+f-EG), or functionalized and decorated with silver nanoparticles [PLA+((f-EG)+Ag)], were fabricated by conventional braiding and using 3D-printing technology. The dimensions of both braided and 3D-printed scaffolds were finely controlled. The results showed that the scaffolds exhibited high porosity (>60%), pore interconnectivity, and pore size suitable for ligament tissue ingrowth, with no relevant differences between PLA and composite scaffolds. The wet state dynamic mechanical analysis at 37 °C revealed an increase in the storage modulus of the composite constructs, compared to neat PLA scaffolds. Either braided or 3D-printed scaffolds presented storage modulus values similar to those found in soft tissues. The tailorable design of the braided structures, as well as the reproducibility, the high speed, and the simplicity of 3D-printing allowed to obtain two different scaffolds suitable for ligament tissue engineering.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030104
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 105: Eco-Friendly Synthesis of Ni/NiO
           Nanoparticles Using Gymnema sylvestre Leaves Extract for Antifungal

    • Authors: Manish Bhoye, Shreyas Pansambal, Parita Basnet, Kun-Yi Andrew Lin, Karina Yanet Gutierrez-Mercado, Alejandro Pérez-Larios, Ankush Chauhan, Rajeshwari Oza, Suresh Ghotekar
      First page: 105
      Abstract: The invention of an easy synthetic approach for extremely impactful nanomaterials (NMs) is one of the crucial research areas in modern science and engineering. In the present work, we describe a cost-effective, simple, rapid and environmentally gracious biogenic fabrication of nickel/nickel oxide nanoparticles (Ni/NiO NPs) using Gymnema sylvestre as a natural fuel. The textural characteristics of as-prepared Ni/NiO NPs were explored using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectra (DRS), photoluminescence spectroscopy (PL), field-emission scanning electron microscope (FESEM), energy dispersive X-ray analysis (EDX), and high-resolution transmission electron microscopy (HRTEM). XRD affirmed the crystalline nature and phase formation of Ni/NiO NPs. The FTIR spectrum ascertains the formation of Ni/NiO NPs, and the band gap of 4.29 eV is revealed from DRS studies. Ni/NiO NPs display an intense emission peak at 576.2 nm in their PL spectrum. The fabrication of pseudo-spherical Ni/NiO NPs was displayed by FESEM and HRTEM images. The particle size obtained from HRTEM was 21 nm, which resembles the median crystallite size ascertained from the XRD data. Additionally, the plausible mechanism for Ni/NiO NPs formation is illustrated. Moreover, as-synthesized Ni/NiO NPs displayed considerable antifungal potential against Candida albicans and Aspergillus niger. Results revealed that the Gymnema sylvestre leaves extract can synthesize Ni/NiO NPs with appealing biological effectiveness for application in the nanomedicine sector.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030105
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 106: Comparative Evaluation of the Sealing
           Ability of a BioCeramic Sealer (iRoot SP) with AH Plus Sealer with Root
           Canal Dentin Using Three Different Techniques of Sealer Application: A
           Combined Dye Extraction and Scanning Electron Microscope Study

    • Authors: Shreya Bhor, Ajay Singh Rao, Unnati Shah, Meetu Mathur, Rodolfo Reda, Francesco Pagnoni, Luca Testarelli, Alexander Maniangat Luke, Ajinkya M. Pawar
      First page: 106
      Abstract: The adaptation of a sealer along with the periphery of the dentinal tubules of the root canal is studied. Various techniques have been used for the application of these sealers onto the canal wall for better adaptation but have not been compared to date. The purpose of the study was to comparatively evaluate the sealing ability of a bioceramic sealer with AH plus sealer with root canal dentin using three different techniques for the application of sealer. One hundred twenty extracted maxillary and mandibular anterior teeth were collected, disinfected, and decoronated at the cemento-enamel junction to maintain a standard working length for all samples. The establishment of the working length (40.10) and instrumentation was performed using a rotary instrument, along with a standard irrigation regimen. The teeth were then divided into two main groups according to the sealer used, i.e., Group A (AH Plus) and Group B (iRoot SP). These two main groups were categorized into three sub-groups depending on the technique of sealer placement, i.e., Subgroup 1 (master cone gutta-percha), Subgroup 2 (bidirectional spiral), and Subgroup 3 (passive ultrasonic activation). Out of the 20 samples, 15 samples were randomly allocated for the assessment of sealing ability using the routine dye extraction method, and to verify the results of the dye extraction method, a more advanced evaluation method, i.e., SEM evaluation, was utilized further. To this end, five random samples from each subgroup were allocated for SEM analysis. The obtained scores were then statistically analyzed using an ANOVA test and Post Hoc Tukey’s test. In the current study, statistical significance was seen among the three main groups and six subgroups with p-values < 0.005. Subgroup B3 performed significantly better than the other subgroups in both the dye extraction method as well as in SEM analysis. The highest microleakage was shown by subgroup A1; it also exhibited poor penetration of sealer in SEM evaluation. The bioceramic sealer (iRoot SP), when applied using passive ultrasonic activation, showed the best results in both the dye extraction method and the SEM evaluation.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030106
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 107: Development and Characterization of
           Bioplastic Synthesized from Ginger and Green Tea for Packaging

    • Authors: Md. Arefin Kowser, Sikder Muhammad Khalid Hossain, Md. Ruhul Amin, Mohammad Asaduzzaman Chowdhury, Nayem Hossain, Osama Madkhali, Md. Rezaur Rahman, Muhammad Tariq Saeed Chani, Abdullah M. Asiri, Jamal Uddin, Mohammed M. Rahman
      First page: 107
      Abstract: The world is suffering from heavy pollution because of synthetic petrochemical plastic used in our daily activities. A possible solution is the use of bioplastic synthesized from natural renewable resources. The present work investigates the development and characterization of polymer bioplastic using ginger tea and green tea to decrease the adverse effect of petrochemical plastic waste for versatile applications. Two kinds of bioplastic samples were produced with two types of tea, ginger tea and green tea, using glycerol, vinegar, starch, and water. SEM (scanning electron microscopy), FTIR (Fourier transformed infrared spectroscopy), mechanical (tensile), TGA (thermogravimetric analysis), DSC (differential scanning calorimetry), and time tests of bioplastic degradation analysis were carried out to evaluate the morphological, mechanical, and thermal behaviors of the synthesized tea bioplastics. The research result showed ginger tea bioplastic had a maximum tensile strength of 2.9 MPa and a minimum elongation of 7.46 mm. More than 78% of degradation occurred in ginger bioplastic within 30 days. Compatible thermal and morphological characteristics are also observed in the prepared bioplastic samples.
      Citation: Journal of Composites Science
      PubDate: 2023-03-07
      DOI: 10.3390/jcs7030107
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 108: Green-Synthesized Graphene for
           Supercapacitors—Modern Perspectives

    • Authors: Ayesha Kausar, Ishaq Ahmad, Tingkai Zhao, M. H. Eisa, O. Aldaghri, Meenal Gupta, Patrizia Bocchetta
      First page: 108
      Abstract: Graphene is a unique nanocarbon nanostructure, which has been frequently used to form nanocomposites. Green-synthesized graphene has been focused due to environmentally friendly requirements in recent technological sectors. A very important application of green-synthesized graphene-based nanocomposite has been observed in energy storage devices. This state-of-the-art review highlights design, features, and advanced functions of polymer/green-synthesized graphene nanocomposites and their utility in supercapacitor components. Green graphene-derived nanocomposites brought about numerous revolutions in high-performance supercapacitors. The structural diversity of conjugated polymer and green graphene-based nanocomposites has facilitated the charge transportation/storage capacity, specific capacitance, capacitance retention, cyclability, and durability of supercapacitor electrodes. Moreover, the green method, graphene functionality, dispersion, and matrix–nanofiller interactions have affected supercapacitance properties and performance. Future research on innovative polymer and green graphene-derived nanocomposites may overcome design/performance-related challenging factors for technical usages.
      Citation: Journal of Composites Science
      PubDate: 2023-03-08
      DOI: 10.3390/jcs7030108
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 109: A Comparison between the Results from
           Linear Analysis and Nonlinear Analysis in the Context of Simulation of
           Biological Materials

    • Authors: Kirana Kumara P
      First page: 109
      Abstract: Surgical simulations require fast and accurate simulation of biological materials. In general, linear analysis is faster but less accurate, whereas nonlinear analysis is more accurate but slower. In this work, a kidney is simulated by using both linear analysis and nonlinear analysis, the results are compared, and the errors quantified. The software package ANSYS is used for the purpose. This work presents detailed results and comparison of linear and nonlinear analysis in the context of simulation of a human kidney, which is not easily found in the literature. The results reinforce the idea that linear analysis is a useful tool for simulating biological materials when solution time is as much important as the accuracy of solutions.
      Citation: Journal of Composites Science
      PubDate: 2023-03-08
      DOI: 10.3390/jcs7030109
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 110: A Mathematical Approach for Sound
           Insulation Characteristics and Cost Optimization of Double-Layer Composite

    • Authors: Liang Zhang, Huawei Zhang, Qiyu Chen, Danfeng Long
      First page: 110
      Abstract: The compressor is the primary source of noise in a refrigeration system. Most compressors are wrapped with multi-layer sound insulation cotton for noise reduction and sound insulation. We explore the sound insulation law of different polyvinyl chloride thicknesses and non-woven fibers. Polyvinyl chloride with varying thicknesses and non-woven fibers are then combined by bonding to study the sound insulation characteristics of a two-layer composite structure. A sound insulation prediction model is established using the multi-parameter nonlinear regression method. An optimal cost mathematical model is established based on experimental and mathematical methods that can quickly determine the optimal cost scheme for different designs with the same effect.
      Citation: Journal of Composites Science
      PubDate: 2023-03-09
      DOI: 10.3390/jcs7030110
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 111: Fabrication and Experimental Analysis
           of Bricks Using Recycled Plastics and Bitumen

    • Authors: Naveen Kumar Koppula, Jens Schuster, Yousuf Pasha Shaik
      First page: 111
      Abstract: Plastic is being used increasingly in daily life. Most of it is not recyclable, and the remaining plastic cannot be used or decomposed. This causes increased plastic waste, contributing to global warming due to thermal recycling. The major objective of this research was to utilise the maximum plastic waste possible to manufacture bricks that compete with the properties of conventional bricks without affecting the environment and the ecological balance. A balanced mixture of high-density polyethylene (HDPE), quartz sand, and some additive materials, such as bitumen, was used to produce these bricks. Various tests were performed to assess the bricks’ quality, such as compression, water absorption, and efflorescence tests. These bricks had a compression strength of 37.5 MPa, which is exceptionally strong compared to conventional bricks. The efflorescence and water absorption tests showed that the bricks were nearly devoid of alkalis and absorbed almost no water. The obtained bricks were light in weight and cost-effective compared to conventional bricks.
      Citation: Journal of Composites Science
      PubDate: 2023-03-10
      DOI: 10.3390/jcs7030111
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 112: A Systematic Approach to Determine the
           Cutting Parameters of AM Green Zirconia in Finish Milling

    • Authors: Laurent Spitaels, Hugo Dantinne, Julien Bossu, Edouard Rivière-Lorphèvre, François Ducobu
      First page: 112
      Abstract: Additive manufacturing (AM) opens new possibilities of obtaining ceramic green parts with a tailored complex design at low cost. Meeting the requirements of highly demanding industries (aeronautical and biomedical, for example) is still challenging, even for machining. Hybrid machines can solve this problem by combining the advantages of both additive and subtractive processes. However, little information is currently available to determine the milling parameters of additively fabricated ceramic green parts. This article proposes a systematic approach to experimentally determine the cutting parameters of green AM zirconia parts. Three tools, one dedicated to thermoplastics, one to composites, and a universal tool, were tested. The tool–material couple standard (NF E 66-520-5) was followed. The lower cost and repeatable generation of smooth surfaces (Ra < 1.6 µm) without material pull-out were the main goals of the study. The universal tool showed few repeatable working points without material pull-out, while the two other tools gave satisfying results. The thermoplastic tool ensured repeatable results of Ra < 0.8 µm at a four times lower cost than the composite tool. Moreover, it exhibited a larger chip thickness range (from 0.003 mm to 0.036 mm). Nevertheless, it generated an uncut zone that must be considered when planning the milling operations.
      Citation: Journal of Composites Science
      PubDate: 2023-03-10
      DOI: 10.3390/jcs7030112
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 113: Properties of Plywood Bonded with
           Formaldehyde-Free Adhesive Based on Poly(vinyl
           alcohol)–Tannin–Hexamine at Different Formulations and
           Cold-Pressing Times

    • Authors: Ratih Afrida Lismana Sari, Muhammad Adly Rahandi Lubis, Rita Kartika Sari, Lubos Kristak, Apri Heri Iswanto, Efri Mardawati, Widya Fatriasari, Seng Hua Lee, Roman Reh, Jan Sedliacik, Muhammad Iqbal Maulana, Lisman Suryanegara, Bambang Subiyanto, Sena Maulana
      First page: 113
      Abstract: The plywood industry’s sustainability, performance, and production costs depend on wood adhesives and the hot pressing technique. In this investigation, a cold-setting plywood adhesive based on polyvinyl alcohol (P), tannin (T), and hexamine (H) was produced. The physical and mechanical properties of plywood were examined at different formulations such as tannin concentration (10% and 20%), hexamine content (5%, 10%, and 15%), and cold-pressing time (3, 6, 12, and 24 h). This study showed that high tannin and hexamine content also increased the solids content, but decreased the average viscosity of the adhesive. Markedly, the cohesion strength of PTH-based adhesives increased from 5.57 Pa at 1/s to 1411.6 Pa at 400/s shear rate, regardless of the adhesive formulation. The shear modulus subsequently decreased as a function of the shear rate and increased with a higher tannin and hexamine content. This study revealed that the higher tannin and hexamine content and longer cold-pressing times could produce plywood with the tested adhesive that met the Japanese standard strength requirements. A combination of PTH-based adhesive prepared with formula 2 and 24 h cold-pressing resulted in the highest TSS value of 1.42 MPa, MOR values of 88.7 MPa, MOE values of 14,025.6 MPa, and wood failure of 47.2%. This study showed the possibility of fabricating eco-friendly plywood panels bonded with PTH-based adhesive using the cold-pressing process as an alternative to conventional plywood.
      Citation: Journal of Composites Science
      PubDate: 2023-03-10
      DOI: 10.3390/jcs7030113
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 114: Why Do Nanoparticles (CNTs) Reduce the
           Glass Transition Temperature of Nanocomposites'

    • Authors: Gad Marom
      First page: 114
      Abstract: This ‘opinion’ article has been undertaken to provide a plausible answer to the question of why nanocomposites that are reinforced by acicular nanoparticles such as carbon nanotubes (CNTs) do not exhibit the anticipated physical properties—particularly, why the glass transition temperature in some compositions exhibits huge decreases, contrary to expectations. It is claimed that this behavior is typical of fully exfoliated, uniformly dispersed nanocomposites, whose structure is that of molecular composites or solid solutions, and which abide by colligative rules.
      Citation: Journal of Composites Science
      PubDate: 2023-03-10
      DOI: 10.3390/jcs7030114
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 115: Statistical Analysis and Optimization
           of the Experimental Results on Performance of Green Aluminum-7075 Hybrid

    • Authors: Olanrewaju Seun Adesina, Abayomi Adewale Akinwande, Oluwatosin Abiodun Balogun, Adeolu Adesoji Adediran, Olufemi Oluseun Sanyaolu, Valentin Romanovski
      First page: 115
      Abstract: The present study assessed the potential of engaging response surface analysis in the experimental design, modeling, and optimization of the strength performance of aluminum-7075 green composite. The design of the experiment was carried out via the Box–Behnken method and the independent variables are rice husk ash (RHA) at 3–12 wt.%, glass powder (GP) at 2–10 wt.%, and stirring temperature (ST) at 600–800 °C. Responses examined are yield, ultimate tensile, flexural, and impact strengths, as well as microhardness and compressive strength. ANOVA analysis revealed that the input factors had consequential contributions to each response, eventually presenting regression models statistically fit to represent the experimental data, further affirmed by the diagnostic plots. The result of the optimization envisaged an optimal combination at 7.2% RHA, 6.2 GP, and 695 °C with a desirability of 0.910. A comparison between the predicted values for the responses and the values of the validation experiment revealed an error of <5% for each response. Consequently, the models are certified adequate for response predictions at 95% confidence, and the optimum combination is adequate for the design of the composite.
      Citation: Journal of Composites Science
      PubDate: 2023-03-13
      DOI: 10.3390/jcs7030115
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 116: Closed-Loop Composite Welding and
           Bonding System Using Radio-Frequency Heating and Pressure

    • Authors: Ian Enriquez, Colin Noronha, Katrina Teo, Anubhav Sarmah, Surabhit Gupta, Ankush Nandi, Blake Fishbeck, Micah J. Green, Aniruddh Vashisth
      First page: 116
      Abstract: Polymer parts often replace traditional metallic parts in load-bearing applications due to their high strength-to-weight ratio, with thermoplastics at the forefront. Conventional manufacturing processes rely on using fasteners or adhesives to hold composite assemblies together, but thermoplastics can be welded together. Ultrasonic welding is widely used but becomes challenging for complex geometries, and new parameters need to be developed for different polymers and specimen geometries. In this work, we developed a closed-loop welding machine that employs the recent discovery of radio-frequency (RF) heating of carbonaceous materials. The machine is successfully able to weld polylactic acid (PLA) coupons with graphitic RF susceptors at the bondline in less than 2 min and using less than 50 W of input RF power. We found that a higher areal density of the graphitic paint lowers the mechanical properties of the weld because the carbonaceous materials hinder polymer chain diffusion. A significant change was not observed in weld properties for welding pressure ranges between 0 and 0.3 MPa. However, increasing out-of-plane welding displacement increased the modulus and strength of the weld. This work provides an interesting new automated system for welding polymer composites using RF fields, with potential applications in various manufacturing industries.
      Citation: Journal of Composites Science
      PubDate: 2023-03-13
      DOI: 10.3390/jcs7030116
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 117: Mechanical and Electrical Properties
           and Electromagnetic-Wave-Shielding Effectiveness of
           Graphene-Nanoplatelet-Reinforced Acrylonitrile Butadiene Styrene

    • Authors: R. B. Jagadeesh Chandra, B. Shivamurthy, M. Sathish Kumar, Niranjan N. Prabhu, Devansh Sharma
      First page: 117
      Abstract: Polymer nanocomposites have attracted global attention as a metal replacement for electrical and electronic applications. Graphene nanoplatelets (GNPs) are widely used as a nanoreinforcement to enhance the functional and structural properties of thermoset and thermoplastic polymers. In the present study, ABS nanocomposites were prepared by reinforcing 3–15 wt.% GNPs in steps of 3 wt.%. The neat ABS and ABS+GNP nanocomposite specimens for the mechanical test were prepared using injection molding, followed by extrusion, as per American Society for Testing and Materials (ASTM) standards. It was found that the modulus of ABS improved due to the reinforcement of GNPs. Additionally, we noticed higher thermal stability of nanocomposites due to the faster heat-conducting path developed in the nanocomposites by the presence of GNPs. However, observed agglomeration of GNPs at higher concentrations and poor wetting with ABS led to the deterioration of the mechanical properties of the nanocomposites. Moreover, 350 µm thick nanocomposite films were manufactured by compression molding, followed by the extrusion method, and we investigated their electrical conductivity, magnetic permeability, permittivity, and electromagnetic-wave-shielding effectiveness. The developed nanocomposites showed improved conductivity and effective electromagnetic wave shielding by absorption. The 15 wt.% GNP-reinforced ABS composite film showed a maximum shielding effectiveness of 30 dB in the X-band.
      Citation: Journal of Composites Science
      PubDate: 2023-03-14
      DOI: 10.3390/jcs7030117
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 118: Fire Resistance of Phosphogypsum- and
           Hemp-Based Bio-Aggregate Composite with Variable Amount of Binder

    • Authors: Girts Bumanis, Martins Andzs, Maris Sinka, Diana Bajare
      First page: 118
      Abstract: Bio-aggregate composites (BACs) are typically formed by binding plant origin aggregates using organic or inorganic binders. Composite boards are being manufactured from hemp shives and Portland cement or lime and such material is associated with the so-called “hempcrete”. To reach a low greenhouse gas emission rate, alternative binders must be considered. Gypsum binder releases a seven times lower amount of CO2 during production compared with Portland cement, while waste gypsum can be even more efficient. In this research, gypsum-based BACs were elaborated and tested. Phosphogypsum was evaluated as an alternative binder. The objective of the research was to evaluate the fire resistance of gypsum- and phosphogypsum-binder-based BAC. In this study, the amount of binder was varied and BACs with a density from 200 to 400 kg/m3 were tested. For the first time, commercial gypsum- and phosphogypsum-based hemp shive BAC fire performance was evaluated using a cone calorimeter. Results indicate that the role of gypsum content has a significant effect on the fire resistance. Time on ignition increased from 14 to 19 s and the heat release rate peak was reduced by 57%. Phosphogypsum binder, compared with commercial gypsum, showed a slight improvement of fire resistance as impurities with high water attraction are in the structure of PG.
      Citation: Journal of Composites Science
      PubDate: 2023-03-14
      DOI: 10.3390/jcs7030118
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 119: An Overview of the Recent Advances in
           Composite Materials and Artificial Intelligence for Hydrogen Storage
           Vessels Design

    • Authors: Mourad Nachtane, Mostapha Tarfaoui, Mohamed amine Abichou, Alexandre Vetcher, Marwane Rouway, Abdeouhaed Aâmir, Habib Mouadili, Houda Laaouidi, Hassan Naanani
      First page: 119
      Abstract: The environmental impact of CO2 emissions is widely acknowledged, making the development of alternative propulsion systems a priority. Hydrogen is a potential candidate to replace fossil fuels for transport applications, with three technologies considered for the onboard storage of hydrogen: storage in the form of a compressed gas, storage as a cryogenic liquid, and storage as a solid. These technologies are now competing to meet the requirements of vehicle manufacturers; each has its own unique challenges that must be understood to direct future research and development efforts. This paper reviews technological developments for Hydrogen Storage Vessel (HSV) designs, including their technical performance, manufacturing costs, safety, and environmental impact. More specifically, an up-to-date review of fiber-reinforced polymer composite HSVs was explored, including the end-of-life recycling options. A review of current numerical models for HSVs was conducted, including the use of artificial intelligence techniques to assess the performance of composite HSVs, leading to more sophisticated designs for achieving a more sustainable future.
      Citation: Journal of Composites Science
      PubDate: 2023-03-14
      DOI: 10.3390/jcs7030119
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 120: Recent Trends in Treatment and
           Fabrication of Plant-Based Fiber-Reinforced Epoxy Composite: A Review

    • Authors: Abdullahi Haruna Birniwa, Shehu Sa’ad Abdullahi, Mujahid Ali, Rania Edrees Adam Mohammad, Ahmad Hussaini Jagaba, Mugahed Amran, Siva Avudaiappan, Nelson Maureira-Carsalade, Erick I. Saavedra Flores
      First page: 120
      Abstract: Natural fiber (NF) is one of the many resources that nature has provided. NFs decompose quickly and are biodegradable, renewable, and cost-effective. It may be scavenged from a variety of plant and animal sources. They are employed as reinforcing materials in polymers for NF composite development. Because of its environmental friendliness and long-term survivability, NF is growing in appeal among academics and researchers for usage in polymer composites. This study aims to offer a thorough evaluation of the most suitable and widely utilized natural fiber-reinforced polymer composites (NFPCs), along with their manufacture, processing, and applications. It also defines several external treatments of NF and their influence on the characteristics of NFPCs. The characteristics of NFPCs are affected by fiber supply, fiber type, and fiber structure. Numerous physical and chemical treatments were tested to see how they affected the thermal and strength properties of natural fiber-reinforced thermoplastic and thermosetting composites. Several polymer composite fabrication techniques were also studied. NFPCs have several disadvantages, notably low fire protection, poor strength properties, and greater moisture absorption, which have prevented their application. It is shown how NFPCs are employed in a variety of industries, particularly automotive and research industries. The review discovered that intentionally changing the regular fiber enhanced the thermochemical and physico-mechanical properties of the NFPCs by means of improving the grip between the fiber surface and the polymer framework. This study aims to provide important and fundamental facts on NF and their composites, which will aid in new investigations, the creation of a creative framework for polymer composite types, and the achievement of Sustainable Development Goals.
      Citation: Journal of Composites Science
      PubDate: 2023-03-15
      DOI: 10.3390/jcs7030120
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 121: Closed-Loop Recycling and
           Remanufacturing of Polymeric Aircraft Parts

    • Authors: Marko Hyvärinen, Mikko Pylkkö, Timo Kärki
      First page: 121
      Abstract: The aviation industry is facing the challenge of reducing fossil fuels and emissions. Fuel efficiency is improved by making efficient powerplant systems and lighter aircraft. Modern passenger aircraft utilize polymeric and polymeric composite materials to achieve lighter structures without compromising strength. The European Union already has legislation to prevent landfilling and to increase the use of recyclable materials in the automotive industry. While older-generation aircraft, made mainly from metallic materials, are easily dismantled and recycled into other uses, such a process does not yet exist for aircraft made from composite materials. In the coming years, the industry will have to answer the question of how retired polymeric composite aircraft structures are to be recycled. One solution to increase the life cycle of polymeric and polymeric composite parts would be closed-loop recycling. In this paper, a perspective of the closed-loop recycling of polymeric aircraft parts is discussed. The technical aspects of recyclability and the different business models for the remanufacture of a finger pinch shroud certified for use in Airbus A350-900 passenger aircraft are investigated. The results show that closed-loop recycling is possible for polymeric aircraft parts. Future studies could include studying an LCA between virgin and recycled materials for a certain part.
      Citation: Journal of Composites Science
      PubDate: 2023-03-15
      DOI: 10.3390/jcs7030121
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 122: Investigation of the Mechanical
           Properties of Sandwich Composite Panels Made with Recyclates and Flax
           Fiber/Bio-Based Epoxy Processed by Liquid Composite Molding

    • Authors: Bharath Ravindran, Michael Feuchter, Ralf Schledjewski
      First page: 122
      Abstract: Despite significant advancements in bio-based natural-fiber-reinforced composites, the recyclability/reprocessing of thermoset composites remains a persistent challenge that needs to be addressed. In the present study, an effort is made to provide a justification for the recyclability/reprocessing assessment of sandwich composite panels made with ‘recyclate’ (i.e., recycled flax/bio-based epoxy composite) cores and (flax/bio-based epoxy) skins produced by liquid composite molding. Resin transfer molding and vacuum-assisted resin infusion processes were used to investigate the influence of production processes on mechanical properties. Two different recyclate sizes—4 mm and 10 mm—were used to fabricate sandwich composite panels to study the effect of size on the mechanical properties of the panels. This study aims to compare the qualities of sandwich panels to those of virgin composite panels in terms of their physical (density) and mechanical properties (tensile and flexural). Additionally, the recyclate packing was verified by employing digital microscopy. The results illustrated that the sandwich panels made with the 4 mm recyclates exhibited better mechanical properties compared to those made with the 10 mm recyclates. In comparison with virgin composite panels, the sandwich composite panels made of flax fiber and (flax/epoxy) recyclate exhibited significantly higher flexural moduli, which was attributed to their moments of inertia. This article emphasizes recycling/reprocessing and demonstrates an effective closed-loop approach. Thus, by preserving the structural integrity of recyclates, sandwich panels could be advantageous for semi-structural applications.
      Citation: Journal of Composites Science
      PubDate: 2023-03-15
      DOI: 10.3390/jcs7030122
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 123: Optimization and Prediction of Thermal
           Conductivity and Electrical Conductivity of Vacuum Sintered
           Ti-6Al-4V-SiC(15 Wt.%) Using Soft Computing Techniques

    • Authors: Adithya Hegde, Raviraj Shetty, Nithesh Naik, B. R. N. Murthy, Madhukar Nayak, Mohan Kumar, Deepika Shanubhogue
      First page: 123
      Abstract: Titanium silicon carbide (Ti3SiC2) is a novel composite material that has found a multitude of uses in the aerodynamics, automobile, and marine industries due to its excellent properties such as high strength and modulus, high thermal and electrical conductivity, high melting point, excellent corrosion resistance, and high-temperature oxidation resistance. These properties are strongly associated with physical properties and microstructural features. Due to difficulties in the synthesis of this material, there have been very few investigations on the relationship between microstructure and physical characteristics of titanium silicon carbide composites processed through powder metallurgical process. However, the importance of thermal conductivity and electrical conductivity of titanium silicon carbide composites in various potential applications has led to keen attention from several researchers. Hence, in this paper, optimization, and prediction of process input parameters during processing under vacuum sintering for achieving maximum electrical and thermal conductivity of Ti-6Al-4V-SiC(15 Wt.%) has been presented. Using Taguchi’s L9 Orthogonal Array, it has been observed that aging temperature (1150 °C), aging time (four hours), heating rate (25 °C/min), and cooling rate (5 °C/min) result in optimum input parameters for achieving the highest electrical conductivity values during the processing of Ti-6Al-4V-SiCp composites. Further, for maximum thermal conductivity values during the processing of Ti-6Al-4V-SiCp composites, aging temperature (1150 °C), aging time (four hours), heating rate (5 °C/min), and cooling rate (5 °C/min) are preferred. A second-order response surface model generated can be effectively used for predicting the electrical conductivity and thermal conductivity during the processing of Ti-6Al-4V-SiCp composites with an accuracy of 99.28% (electrical conductivity) and 99.14% (thermal conductivity). By comparing the experimental results along with the results of the mathematical model and the BPANN model results for nine trials, it was observed that the estimated value is accurate for all tests with an error of 0.39% (electrical conductivity) and 0.48% (thermal conductivity). Further, from X-ray diffraction studies and microstructural analysis, it has been observed that aging at 1150 °C for four hours resulted in the formation of a ternary carbide phase of titanium silicon carbide (Ti3SiC2), which resulted in maximum electrical conductivity (4,260,000 Ω−1 m−1) and thermal conductivity (36.42 W/m·K) of the Ti-6Al-4V-SiC (15 Wt.%) composite specimen.
      Citation: Journal of Composites Science
      PubDate: 2023-03-15
      DOI: 10.3390/jcs7030123
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 124: Man-Made Raw Materials for the

    • Authors: Sultan Auyesbek, Nuraly Sarsenbayev, Aisulu Abduova, Bakhytzhan Sarsenbayev, Saken Uderbayev, Zhambyl Aimenov, Gulmira Kenzhaliyeva, Uzakbai Akishev, Taslima Aubakirova, Gaukhar Sauganova, Eldar Amanov, Olga Kolesnikova, Igor Panarin
      First page: 124
      Abstract: This paper presents the development of composite silicate mass compositions based on man-made waste for the production of autoclave hardening products, as well as the results of physico-chemical studies of hydration products of silicate materials. The possibility, expediency and efficiency of using multi-tonnage technogenic waste of Kazakhstan in the industry of composite building materials is shown. Based on the results of the conducted research, the composition of a composite silicate mass based on burnt carbonate-barium tailings (8–12%), electrothermophosphoric slags (82–90%) or sand and dust from cement kiln electrofilters (2–5%) for the production of autoclave hardening products was developed. It was found that the cementing substance in composite silicate materials is represented by CSH(B) calcium silicate hydrates, tobermorite and serpentine. The simultaneous presence of fibrous and crystalline calcium and magnesium silicate hydrates in hydration products leads to the creation of composite products with a maximum strength of 41–49 MPa.
      Citation: Journal of Composites Science
      PubDate: 2023-03-16
      DOI: 10.3390/jcs7030124
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 125: Flexural Behaviour of Foam Cored
           Sandwich Structures with Through-Thickness Reinforcements

    • Authors: Ghilané Bragagnolo, Andrew D. Crocombe, Stephen L. Ogin, Alessandro Sordon, Iman Mohagheghian
      First page: 125
      Abstract: Composite sandwich structures are well-suited for applications requiring high bending strength, flexural rigidity, crashworthiness, and light weight. However, skin–core debonding and core failure remain a barrier to optimal structural performance when polymeric foams are used as core materials. Suppressing or compartmentalising these failure modes can enhance the structural integrity of sandwich structures. In this paper, the flexural response of a sandwich structure was improved by adding carbon fibre-reinforced plastic in the form of through-thickness ribs during the manufacturing process. The effect of the position of the ribs was investigated using a quasi-static three-point bend test. A camera was used to capture failure events, while the digital image correlation technique provided the full-strain field at different stages of loading. Improved flexural performance was obtained when a reinforcement was placed on either side of the loading roller. With this configuration, skin–core debonding was restricted to a confined portion of the panel, resulting in a more localised and stable fracture process, which involved enhanced foam crushing and hardening. A simple FEA approach has been adopted in this paper and has proven to be an effective approach for capturing the details of the failure process, including the debonding in the composite foam structures, without the need for complex and computationally expensive interface modelling.
      Citation: Journal of Composites Science
      PubDate: 2023-03-16
      DOI: 10.3390/jcs7030125
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 126: Essential Oil-Added
           Chitosan/Gelatin-Based Active Packaging Film: A Comparative Study

    • Authors: Swarup Roy, Seung-Jae Min, Jong-Whan Rhim
      First page: 126
      Abstract: Active packaging films based on chitosan/gelatin were prepared using a solution casting method by adding various essential oils (lime, tea tree, rosemary, and thyme essential oils), and their effects were compared. The fabricated films were characterized and various physical properties as well as the antioxidant performance of the films were studied. Adding essential oils to the polysaccharide/protein biopolymer mixtures resulted in compatible films with high transparency (>90% transparency). The mechanical strength and stiffness of the chitosan/gelatin films were improved by about 30% in the presence of essential oil, but the flexibility slightly decreased, and the stiffness improved. On the other hand, the water vapor barrier properties, thermal stability, and hydrophobicity of the essential oil-containing films were not significantly changed. Adding various essential oils significantly enhanced the antioxidant activity of chitosan/gelatin-based films. Therefore, bio-based functional films with added essential oils can be applied in active packaging applications.
      Citation: Journal of Composites Science
      PubDate: 2023-03-17
      DOI: 10.3390/jcs7030126
      Issue No: Vol. 7, No. 3 (2023)
  • J. Compos. Sci., Vol. 7, Pages 43: Acknowledgment to the Reviewers of J.
           Compos. Sci. in 2022

    • Authors: J. Compos. Sci. Editorial Office J. Compos. Sci. Editorial Office
      First page: 43
      Abstract: High-quality academic publishing is built on rigorous peer review [...]
      Citation: Journal of Composites Science
      PubDate: 2023-01-17
      DOI: 10.3390/jcs7020043
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 44: Significance of Sandwich Panel’s
           Core and Design on Its Impact Resistance under Blast Load

    • Authors: Yaqoub S. AlAhmed, Noha M. Hassan, Zied Bahroun
      First page: 44
      Abstract: Extensive research is conducted on enhancing the blast mitigation performance of the sandwich panels by examining different design parameters, and core geometries. Nevertheless, there is no direct comparison between those alternatives to evaluate their contribution to maximizing energy absorption. In this research, three core designs honeycomb, mushroom, and tubular were compared to determine the influence of core shape on the panel’s impact resistance against blast load. In addition to varying core shapes, the effect of plate thickness and the spacing between the core shapes are also examined. Finite element analysis was used to evaluate the performance of these designs. Twenty-seven numerical experiments were performed and then analyzed using regression analysis. Results reveal that the tubular sandwich panel exhibited minimum deformation, and least damage and contributed to the highest kinetic energy dissipation. On the other hand, honeycomb core structures recorded the highest internal energy dissipation, largest deformation, and damage. Despite those differences, core shape and core spacing were not as influential in resisting blast load compared to plate thickness. Facade plate thickness was the most significant factor. Results suggest that more research needs to be targeted toward enhancing façade plate stiffness for better mitigation of blast load.
      Citation: Journal of Composites Science
      PubDate: 2023-01-17
      DOI: 10.3390/jcs7020044
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 45: Temperature-Dependent Deformation
           Behavior of “γ-austenite/δ-ferrite” Composite
           Obtained through Electron Beam Additive Manufacturing with Austenitic
           Stainless-Steel Wire

    • Authors: Elena Astafurova, Galina Maier, Evgenii Melnikov, Sergey Astafurov, Marina Panchenko, Kseniya Reunova, Andrey Luchin, Evgenii Kolubaev
      First page: 45
      Abstract: Temperature dependence of tensile deformation behavior and mechanical properties (yield strength, ultimate tensile strength, and an elongation-to-failure) of the dual-phase (γ-austenite/δ-ferrite) specimens, obtained through electron-beam additive manufacturing, has been explored for the first time in a wide temperature range T = (77–300) K. The dual-phase structures with a dendritic morphology of δ-ferrite (γ + 14%δ) and with a coarse globular δ-phase (γ + 6%δ) are typical of the as-built specimens and those subjected to a post-production solid–solution treatment, respectively. In material with lower δ-ferrite content, the lower values of the yield strength in the whole temperature range and the higher elongation of the specimens at T > 250 K have been revealed. Tensile strength and stages of plastic flow of the materials do not depend on the δ-ferrite fraction and its morphology, but the characteristics of strain-induced γ→α′ and γ→ε→α′ martensitic transformations and strain-hardening values are different for two types of the specimens. A new approach has been applied for the analysis of deformation behavior of additively fabricated Cr-Ni steels. Mechanical properties and plastic deformation of the dual-phase (γ + δ) steels produced through electron beam additive manufacturing have been described from the point of view of composite materials. Both types of the δ-ferrite inclusions, dendritic lamellae and globular coarse particles, change the stress distribution in the bulk of the materials during tensile testing, assist the defect accumulation and partially suppress strain-induced martensitic transformation.
      Citation: Journal of Composites Science
      PubDate: 2023-01-22
      DOI: 10.3390/jcs7020045
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 46: Drilling Response of Carbon
           Fabric/Solid Lubricant Filler/Epoxy Hybrid Composites: An Experimental

    • Authors: Yermal Shriraj Rao, Nanjangud Subbarao Mohan, Nagaraja Shetty, Subash Acharya
      First page: 46
      Abstract: Carbon-fiber-reinforced epoxy composite (CEC) has gained widespread acceptance as a structural material in various applications. Drilled holes are essential for assembling composite material components. Reducing drilling-induced damage and temperature effects is crucial for improved surface quality and integrity of the drilled composite. In the present work, drilling experiments were conducted on CEC, hexagonal-boron nitride (h-BN) dispersed CEC, and molybdenum disulfide (MoS2) dispersed CEC at three different levels of spindle speed, feed, and drill diameter using solid carbide twist drills. The filler concentrations used in this study were 4, 6, and 8 wt%. Analysis of variance (ANOVA) was used to determine the significance of input factors (feed, spindle speed, drill diameter, and filler concentration) on the drilling responses such as thrust force, temperature, arithmetic mean surface roughness (Ra), and push-out delamination factor (DFexit). The average drilling temperature, Ra, and DFexit of MoS2 dispersed CEC were reduced by 24.7, 46.5, and 11.3%, respectively, when compared to neat CEC. In h-BN dispersed CEC, the average drilling temperature, Ra, and DFexit were reduced by 25.2, 40.9, and 13.2%, respectively, compared to neat CEC. The lubricating properties and high thermal conductivity of filler added to epoxy are responsible for the lower temperature and improved hole surface finish. The improved delamination resistance in filler-loaded CEC is due to the strengthening of the matrix and fiber–matrix interface. Scanning electron microscopy (SEM) was used to examine the morphology of the drilled composite surface. The spindle speed of 5500 rpm, feed of 0.03 mm.rev−1, and filler loading of 4 wt% produced the minimum Ra and DFexit. The response surface method (RSM) was applied to determine the input parameters based on multi-response optimum criteria.
      Citation: Journal of Composites Science
      PubDate: 2023-01-23
      DOI: 10.3390/jcs7020046
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 47: Processing of 3-(Trimethoxysilyl)propyl
           Methacrylate (TMSPM) Functionalized Barium Titanate/Photopolymer
           Composites: Functionalization and Process Parameter Investigation

    • Authors: Ajmal Zarinwall, Rytis Mitkus, Axel Marth, Viktor Maurer, Michael Sinapius, Georg Garnweitner
      First page: 47
      Abstract: To improve the performance of lead-free piezoelectric composites, the functionalization of the filler particles has been suggested as a successful strategy in several recent reports. The details of the functionalization process, however, are not clear, nor is its influence on the dielectric properties of the composites. This study reports a systematic investigation of the functionalization process parameters of barium titanate nanoparticles (BTONP) with 3-(trimethoxysilyl)propyl methacrylate (TMSPM) used as a linker to an acrylate-based matrix polymer. Functionalization process temperature, time, functionalization agent ratio, solvent, and catalyst influence on the functionalization degree were measured by thermogravimetric analysis (TGA), elemental analysis, and Fourier-transform infrared (FTIR) spectroscopy. Elevated temperature and average functionalization time led to the highest functionalization degree in the form of a TMSPM monolayer on the particle surface. Three solvents, with and without catalysts, were investigated and two types of functionalized BTONP were selected for composite manufacturing. To this end, the functionalized particles were used to manufacture 10 vol.% BTONP/photopolymer UV light-curable composite suspensions. After solidification of the suspensions by exposure to UV light, the microstructure and dielectric properties of the resulting composites were investigated. It was seen that functionalization improves the dispersion of particles, increases suspension viscosity, and decreases the curing depth and dielectric properties.
      Citation: Journal of Composites Science
      PubDate: 2023-01-24
      DOI: 10.3390/jcs7020047
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 48: Assessment of the Potential of Waste
           Copper Chromium and Arsenic (CCA)-Treated Timber Fibre Reinforced
           Polypropylene Composites for Construction

    • Authors: Jacob Nelson, Kim L. Pickering, Mohammad D. H. Beg
      First page: 48
      Abstract: This paper investigates the potential of recycling waste copper chromium and arsenic (CCA)-treated timber for use as a reinforcement material in wood–plastic composites (WPCs) produced for use in construction, including an assessment of mechanical properties and the leaching of heavy metals. Wood flour was obtained through mechanical grinding, and fibres were obtained through alkaline digestion followed by bleaching. Composites produced with 40 wt.% bleached fibres showed increased tensile strength from 18.5 MPa for the polypropylene used as the matrix to 27.6 MPa. Likewise, the Young’s modulus was increased from 0.84 to 2.33 GPa. The treatment of fibres was found to reduce arsenic concentration by up to 99.9%. Furthermore, the arsenic in the leachate from composites was found to decrease from 41.29 to 0.07 ppb when comparing CCA-treated wood flour composites to bleached fibre composites. The composites’ material properties indicate that the use of end-of-life CCA-treated timber could be used to produce a composite material that could be used in New Zealand’s building sector to meet the requirements of semi-structural applications.
      Citation: Journal of Composites Science
      PubDate: 2023-01-25
      DOI: 10.3390/jcs7020048
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 49: Mechanical Properties of Post-Cured
           Eggshell-Filled Glass-Fibre-Reinforced Polymer Composites

    • Authors: Suhas Kowshik, Sathyashankara Sharma, Sathish Rao, Manjunath Shettar, Pavan Hiremath
      First page: 49
      Abstract: Eggshells are a potentially polluting industrial waste that are disposed of as landfill which has proven to be hazardous to the environment. The usage of chicken eggshells as a biofiller for polymer matrix composites instead of its disposal as landfill has proven advantageous in various studies. On the other hand, using eggshells as a filler material to replace inorganic calcium carbonate usage would be another environment friendly act. The present study is focused on studying the effects of eggshell filler addition and post-curing on polymer composites which could be utilised for domestic applications. Herein, uncarbonised and carbonised eggshell filler material were processed from waste eggshells. Hybridisation of the carbonised and uncarbonised eggshell filler was carried out. All three variants of eggshell fillers (10 wt.%) were used in the fabrication of composites. A hand lay-up technique was employed in the fabrication of unfilled composites along with three variants of filled composites, namely, uncarbonised, carbonised, and hybrid eggshell filled composites. The fabricated and cured composites were further subjected to post-curing at a temperature of 60 °C for a period of 2 h. All four variants of post-cured composites were then subjected to mechanical testing according to American Society for Testing and Materials (ASTM) standards. The tests revealed that all three variants of filled composites possess better mechanical properties in comparison with unfilled composites. Further, in comparison with unfilled composites, the carbonised eggshell filled composites showcased 42% and 49% improvement in flexural and tensile properties, respectively. The modes of failure of the specimens were observed and tabulated. SEM imaging revealed that the eggshell filler contributed to the strengths of the composites by means of arresting and deviating cracks. It was also observed that the post-cured specimens displayed improved properties when compared with our previous studies on non-post-cured specimens. In summary, the study showcased the benefits of eggshell filler addition and the post-curing of polymer composites.
      Citation: Journal of Composites Science
      PubDate: 2023-02-01
      DOI: 10.3390/jcs7020049
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 50: Influence of Alternating Current
           Density on the Mechanical Behavior and Microstructure of PEO-Coated 7075
           Aluminum Alloy

    • Authors: Tumur Ochir Erdenebat, Lkhagvaa Telmenbayar, Daejeong Yang, Minjung Song, Adam Gopal Ramu, Dongjin Choi
      First page: 50
      Abstract: The objective of the study was to investigate the characteristics of coatings formed on 7075 Al alloy using a plasma electrolytic oxidation (PEO) method in silicate electrolytes under alternating current conditions. The properties of the coatings were evaluated based on the current density applied during the experimental process. To analyze the samples, the surface and cross-sectional images of the coatings were observed using scanning electron microscopy. The results showed that the PEO coatings were between 25–102 µm in thickness, and the thickness was found to be dependent on the applied current density. The hardness values of the PEO coatings were found to be significantly, approximately three times, higher than the uncoated alloy. Wear analysis revealed that the PEO coatings formed under current densities of 8.8 A/dm2 and 17.8 A/dm2 exhibited the best wear resistance among all the coatings. In addition, the PEO coatings also displayed good corrosion resistance, with the resistance of the coatings formed under the current densities of 13.5 A/dm2 and 17.8 A/dm2 being significantly improved compared to that of the bare Al alloy. The most effective anticorrosion PEO coating was found to be the one formed under a current density of 17.8 A/dm2. The wear depths of the PEO coatings formed under current densities of 8.8 A/dm2 and 17.8 A/dm2 were low, resulting in high wear resistance. Among all the PEO coatings, the coating formed under a current density of 17.8 A/dm2 showed the best overall anticorrosion and mechanical properties. Overall, the study highlights the potential of PEO coatings in significantly improving the corrosion and wear resistance of 7075 Al alloy. The results of the study provide useful information for the selection of current density for the PEO coating process on 7075 Al alloy to achieve desired properties.
      Citation: Journal of Composites Science
      PubDate: 2023-02-01
      DOI: 10.3390/jcs7020050
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 51: High-Hardness, Water-Stable, and
           UV-Resistant Conductive Coatings Based on Waterborne
           PEDOT:PSS/Epoxy/(KH560/SiO2) Composite

    • Authors: Zhanqi Li, Ling Zhu, Xiaowen Xie, Meng Zhou, Changqing Fu, Shuai Chen
      First page: 51
      Abstract: Despite the fact that PEDOT:PSS has been successfully used in the field of flexible electronics, some of its applications in the domain of rigid conductive coating have been limited by the pricey cost and subpar mechanical properties (hardness, adhesion, and moisture absorption) of the commercially available Clevios™ PH 1000, as well as the poor conductivity, film formation, and mechanical properties of the self-made PEDOT:PSS. In the process of investigating the low-cost preparation of PEDOT-based conductive polymer coatings, we discovered that self-made PEDOT:PSS, a waterborne epoxy resin, and a bio-based epoxy curing agent can be blended uniformly to produce good film-forming conductive coatings. Later, the addition of KH560-modified nano-SiO2 further improved the coating’s hardness while ensuring a modest increase in conductivity. Meanwhile, the inadequacies of the epoxy resin, which are not UV-resistant, were considerably improved by the synergistic action of PEDOT:PSS and the modified SiO2. The result is a low-cost method designed for creating conductive coatings that are UV-resistant and may be utilized for electromagnetic, electrothermal, and antistatic shielding applications. Such a PEDOT:PSS/epoxy composite system and its design approach will broaden the scope of PEDOT:PSS’s application and will inspire future research in and practical implementations of PEDOT:PSS-based conducting coatings.
      Citation: Journal of Composites Science
      PubDate: 2023-02-02
      DOI: 10.3390/jcs7020051
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 52: Synthesis of Chitosan Capped Zinc
           Sulphide Nanoparticle Composites as an Antibacterial Agent for Liquid
           Handwash Disinfectant Applications

    • Authors: Eny Kusrini, Lee D. Wilson, Kanya Maharani Padmosoedarso, Dias Puspitaning Mawarni, Muhammad Sufyan, Anwar Usman
      First page: 52
      Abstract: There is a need to develop alternative disinfectants that differ from conventional antibiotics to address antibacterial resistance, along with specialized materials for biomedical applications. Herein, we report on the synthesis of zinc sulfide (ZnS) capped with chitosan (CS) to produce CS-ZnS nanocomposites (NCs), which were assayed for antibacterial activity in liquid handwash formulations. The CS-ZnS NCs were prepared using the bottom-up wet-chemical method. The role of CS as the capping agent was investigated by varying the ratio of CS with respect to the ZnS precursor. The prepared CS-ZnS NCs were characterized using complementary spectral methods: scanning electron microscopy–energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The antibacterial activities of liquid handwash (LH) formulations containing 1% (w/w) CS-ZnS NCs were tested against Staphylococcus aureus and Escherichia coli using the agar diffusion test method. This LH formulation displayed antibacterial activity against S. aureus with an average inhibition zone diameter in the range of 16.9–19.1 mm, and met the quality standards set by the National Standardization Agency. The formulated LH solutions containing CS-ZnS NCs showed antibacterial activity, which suggests that the CS-ZnS NCs have potential as an alternative active ingredient for tailored and non-irritant antibacterial LH detergents.
      Citation: Journal of Composites Science
      PubDate: 2023-02-02
      DOI: 10.3390/jcs7020052
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 53: Composite Single Lap Shear Joint
           Integrity Monitoring via Embedded Electromechanical Impedance Sensors

    • Authors: Steven P. Caldwell, Donald W. Radford
      First page: 53
      Abstract: Composite bonded structure is a prevalent portion of today’s aircraft structure. Adequate bond integrity is a critical aspect of fabrication and service, especially since many of today’s structural bonds are critical for flight safety. Over the last decade, non-destructive bond evaluation techniques have improved but still cannot detect a structurally weak bond that exhibits full adherend/adhesive contact. The result is that expensive and time-consuming structural proof testing continues to be required to verify bond integrity. The objective of this work is to investigate the feasibility of bondline integrity monitoring using piezoelectric sensors, embedded at different locations within the composite joint, and to assess the benefits of monitoring the thickness mode in addition to the radial mode. Experiments and analyses are performed on single lap shear composite joints, with and without embedded sensors, subjected to incrementally increasing tensile loads. The results indicate that the embedded piezoelectric sensors measure a change in the resonance in both the radial and thickness mode during incremental loading and that the thickness resonance shows enhanced sensitivity to impending failure. Thus, it is demonstrated that monitoring both modes of the piezoelectric sensor provides addition details for prognostic performance evaluation.
      Citation: Journal of Composites Science
      PubDate: 2023-02-02
      DOI: 10.3390/jcs7020053
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 54: Prediction of Composite Mechanical
           Properties: Integration of Deep Neural Network Methods and Finite Element

    • Authors: Kimia Gholami, Faraz Ege, Ramin Barzegar
      First page: 54
      Abstract: Extracting the mechanical properties of a composite hydrogel; e.g., bioglass (BG)–collagen (COL), is often difficult due to the complexity of the experimental procedure. BGs could be embedded in the COL and thereby improve the mechanical properties of COL for bone tissue engineering applications. This paper proposed a deep-learning-based approach to extract the mechanical properties of a composite hydrogel directly from the microstructural images. Four datasets of various shapes of BGs (9000 2D images) generated by a finite element analysis showed that the deep neural network (DNN) model could efficiently predict the mechanical properties of the composite hydrogel, including the Young’s modulus and Poisson’s ratio. ResNet and AlexNet architecture were tuned to ensure the excellent performance and high accuracy of the proposed methods with R-values greater than 0.99 and a mean absolute error of the prediction of less than 7%. The results for the full dataset revealed that AlexNet had a better performance than ResNet in predicting the elastic material properties of BGs-COL with R-values of 0.99 and 0.97 compared to 0.97 and 0.96 for the Young’s modulus and Poisson’s ratio, respectively. This work provided bridging methods to combine a finite element analysis and a DNN for applications in diverse fields such as tissue engineering, materials science, and medical engineering.
      Citation: Journal of Composites Science
      PubDate: 2023-02-03
      DOI: 10.3390/jcs7020054
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 55: Application of Composite Materials for
           Energy Generation Devices

    • Authors: Tomasz Trzepieciński, Temesgen Batu, Fasikaw Kibrete, Hirpa G. Lemu
      First page: 55
      Abstract: Globally, electricity demand rises by 1.8% per year; according to the American Energy Information Administration, global energy demand will increase by 47% over the next 30 years, driven by demographic and economic growth. Global demand for electricity is growing faster than renewable energy sources. Electricity production from renewable sources (i.e., biomass energy, geothermal energy, hydro energy, solar energy, tidal energy, wind energy) is on its way to strong growth around the world over the next dozen years. With the increasing demand for energy, new technologies and materials are being developed to replace exhaustible traditional construction materials. This article aims to provide a comprehensive overview of the research into the application of composite materials in mainstream power generation. The main energy generation technologies, i.e., photovoltaic panels, wind turbines, fuel cells, and biogas generators, were analysed and discussed. The review presented in this article also covers the latest achievements and prospects for the use of composite materials in energy generation devices.
      Citation: Journal of Composites Science
      PubDate: 2023-02-03
      DOI: 10.3390/jcs7020055
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 56: From Flat Plates to Sinusoidal
           Structures: Influence of Geometry on the Energy Absorption Capability of
           Carbon/Epoxy Composites

    • Authors: Mehmet Engül, Nuri Ersoy
      First page: 56
      Abstract: Composite structures have excellent performance related to energy absorption during crush events. Among various factors, geometry has a significant influence on the specific energy absorption (SEA) performance of composites; however, the variation of crush-induced failure mechanisms for various geometric features and the way they affect energy absorption capability have not yet been fully clarified. Moving from simple to complex composite structures, a holistic study investigating the influence of geometry on the SEA is required. This paper presents experimental and numerical investigations of the crushing process for flat plates, semi-circle geometries, and sinusoidal structures with different diameters and numbers of curvatures. In a numerical analysis, a finite element (FE) model with the idea of an artificial plug-initiator was developed for the accurate and realistic crushing behavior of sinusoidal specimens. The results were discussed and compared in terms of the observed failure mechanisms. The sinusoidal structure with the highest energy absorption capability was identified.
      Citation: Journal of Composites Science
      PubDate: 2023-02-03
      DOI: 10.3390/jcs7020056
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 57: Comparative Analysis of ANN-MLP,
           ANFIS-ACOR and MLR Modeling Approaches for Estimation of Bending Strength
           of Glulam

    • Authors: Morteza Nazerian, Masood Akbarzadeh, Antonios N. Papadopoulos
      First page: 57
      Abstract: Multiple linear regression (MLR), adaptive network-based fuzzy inference system–ant colony optimization algorithm hybrid (ANFIS-ACOR) and artificial neural network–multilayer perceptron (ANN-MLP) were tested to model the bending strength of Glulam (glue-laminated timber) manufactured with a plane tree (Platanus orientalis L.) wood layer adhered with different weight ratios (WR) of modified starch/urea formaldehyde (UF) adhesive containing different levels of nano-ZnO (NC) used at different levels of the press temperature (Tem) and time (Tim). According to X-ray diffraction (XRD) and stress–strain curves, some changes in the behavior of the product were seen. After selecting the best model through determining statistics such as the determination coefficient (R2) and root mean square error (RMSE), mean absolute error (MAE) and sum of squares error (SSE), the production process was optimized to obtain the highest modulus of rupture (MOR) using the Genetic Algorithm (GA) combined with MLP. It was determined that the MLP had the best accuracy in estimating the response. According to the MLP-GA hybrid, the optimum input values for obtaining the best response include: WR—49.1%, NC—3.385%, Tem—199.4 °C and Tim—19.974 min.
      Citation: Journal of Composites Science
      PubDate: 2023-02-04
      DOI: 10.3390/jcs7020057
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 58: Influence of Variatropy on the
           Evaluation of Strength Properties and Structure Formation of Concrete
           under Freeze-Thaw Cycles

    • Authors: Alexey N. Beskopylny, Evgenii M. Shcherban, Sergey A. Stel’makh, Levon R. Mailyan, Besarion Meskhi, Andrei Chernil’nik, Diana El’shaeva
      First page: 58
      Abstract: The resistance of concrete structures to the impact of cyclic freezing and thawing is one of the key long-term characteristics, which further determines the operation and its service life. To date, the resistance to alternating freeze-thawing cycles under various operating conditions of concrete structures has been little studied related to several manufacturing processes: simple vibrated, variotropic centrifuged, and improved variotropic vibrocentrifuged. The purpose of this study is to investigate the effect of heavy concrete manufacturing technology on the resistance of concrete to alternate freezing and thawing in an aggressive environment of 5% sodium chloride solution, as well as to study the trend in strength characteristics and weight loss of vibrated, centrifuged and vibrocentrifuged concretes after a series of freezing and thawing cycles. Standardized techniques for assessing the characteristics of concrete and scanning electron microscopy were used. Vibrated, centrifuged, and vibrocentrifuged concretes made from the same raw materials have differences in weight loss of 4.5%, 3%, and 2%, respectively, and in strength of 15.0%, 13.5%, and 10%, respectively, when tested for frost resistance in similar environments after 15 cycles by the accelerated method. Centrifuged and especially vibrocentrifuged variotropic concrete have greater resistance and endurance to cycles of alternate freezing and thawing compared to vibrated.
      Citation: Journal of Composites Science
      PubDate: 2023-02-04
      DOI: 10.3390/jcs7020058
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 59: Biochar Derived from Rice by-Products
           for Arsenic and Chromium Removal by Adsorption: A Review

    • Authors: Stella Chatzimichailidou, Maria Xanthopoulou, Athanasia K. Tolkou, Ioannis A. Katsoyiannis
      First page: 59
      Abstract: Environmental pollution by arsenic (As) and hexavalent chromium (Cr(VI)) has been one of the most serious environmental problems in recent years around the world. Their presence in water is a result of both natural and anthropogenic activities, and poses serious risks to human health due to their high toxicity. Adsorption is a leading method used to remove arsenic and chromium, with biochar, a carbonaceous pyrolytic product made from various types of biomass, under low oxygen conditions, being one of the most common adsorbents due to its high surface area. Although biochar’s ability to immobilize and remove As and Cr(VI) is high, in order to increase the adsorption capacity and nutrient release potential of rice husk biochar, it is essential to select an appropriate pyrolysis and biochar modification technique. Physical or biological activation, steam/gas activation, UV irradiation, magnetization, alkali/acid treatment, and nano-modification are the main modification methods that will be discussed in this review. These modifications have led to multi-fold enhancement in adsorption/reduction capacity of As and Cr(VI), compared with plain biochar. This review provides a recent literature overview of the different biochar modification methods, as well as the factors that influence their capacity to successfully remove As and Cr(VI), along with regeneration potentials.
      Citation: Journal of Composites Science
      PubDate: 2023-02-04
      DOI: 10.3390/jcs7020059
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 60: The Effect of Ca, Sr, and Ba Chloride
           Complexes with Dibenzo-18-Crown-6 Ether as Catalysts on the Process
           Criteria for the Efficiency of Cumene Oxidation (the First Stage in the
           Chain of Polymer Composite Production)

    • Authors: Nikolai V. Ulitin, Nikolay A. Novikov, Yana L. Lyulinskaya, Daria A. Shiyan, Konstantin A. Tereshchenko, Natalia M. Nurullina, Marina N. Denisova, Yaroslav O. Mezhuev, Kharlampii E. Kharlampidi
      First page: 60
      Abstract: A study was made on the effect of Ca, Sr, and Ba chloride complexes with dibenzo-18-crown-6 ether as catalysts on the process criteria of the efficiency of industrial cumene oxidation using kinetic modeling. It is the first stage in the process chain of polymer composite production. The kinetic scheme of the process is made of classical reactions of the radical chain mechanism (reactions of initiation, chain propagation, and chain termination), molecular reactions, reactions of formation of intermediate adducts “component of the reaction mixture—catalyst” and their decomposition, as well as reactions that take into account the specifics of the catalyst used: (1) formation of planar catalyst complexes with various substances; (2) formation of acetophenone along the catalytic path; (3) hydration of the intermediate adduct “α-methylstyrene—catalyst” to the required alcohol. It is shown that the kinetic model fully reproduces the experimental time dependencies of the cumene hydroperoxide concentration in the cumene oxidation and cumene hydroperoxide decomposition. Using the kinetic model, computational experiments were carried out, as a result of which the following conclusions were made: (1) among the considered catalysts, the complex of Sr chloride with dibenzo-18-crown-6 ether should be recognized as the best, provided that it is used at temperatures of 393–413 K and an initial concentration < 2 mmol/L; (2) to ensure selectivity comparable to the selectivity of a non-catalytic process, it is necessary to conduct the catalytic process at a lowest possible initial concentration of any of the considered catalysts.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020060
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 61: Tailoring Variations in the
           Microstructures, Linear/Nonlinear Optical, and Mechanical Properties of
           Dysprosium-Oxide-Reinforced Borate Glasses

    • Authors: Ahmed M. Henaish, Osama M. Hemeda, Enas A. Arrasheed, Rizk M. Shalaby, Ahmed R. Ghazy, Ilya A. Weinstein, Moustafa A. Darwish, Ekaterina L. Trukhanova, Alex V. Trukhanov, Sergei V. Trukhanov, Ahmed F. Al-Hossainy, Nermin A. Abdelhakim
      First page: 61
      Abstract: Hybrid dysprosium-doped borate glassy samples [B-Gly/Dy]HDG (Borate Glass/Dysprosium)Hybrid Doped Glass were prepared in this study via the melt-quenching method. Its linear/nonlinear optical, photoluminescence, hardness indentation, and micro-creep properties were analyzed. The amorphous structure for all the prepared samples was confirmed from the XRD patterns. In addition, density functional theory (DFT), optimized by TD-DFT and Crystal Sleuth, was used to study the structure and crystallinity of the [B-Gly/Dy]HDG as isolated molecules and agreed with the peaks of experimental XRD patterns. Additionally, theoretical lattice types were studied using Polymorph, a content studio software, and orthorhombic Pc21b (29) and triclinic P-1 (2) structures were provided. Both mechanical and optical properties were responses to different concentrations of Dy2O3 in the glassy borate system. It was found that the length of indentation increases by increasing the load time, and the hardness decreases by increasing the load time. The stress exponent value also increased from 4.1 to 6.3. The indentation strain increases by increasing the load time. The direct optical band gap was evaluated using the Davis–Mott relation. Urbach energy and its connection to the disorder degree in materials were studied depending on the Dy2O3 concentration. The acquired optical parameters were also analyzed to determine the nonlinear refractive index as well as the linear and third-order nonlinear optical susceptibility of the investigated glass samples. The photoluminescence emission spectra were recorded, and their attributed transitions were studied. The mechanical studies showed that the hardness values increased by increasing Dy2O3 concentrations from 4160.54 to 5631.58 Mpa. The stress exponent value also increased from 4.1 to 6.3. Therefore, the higher value of stress exponent (S) is more resistant to indentation creep.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020061
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 62: Taguchi Method Optimization of Water
           Absorption Behavior by Wheat Straw-Basalt Hybrid Brake Pad Composite

    • Authors: Worku Mamuye Yilma, Balkeshwar Singh, Getinet Asrat, Nazia Hossain
      First page: 62
      Abstract: The application of biomass-derived composite material is in high demand worldwide in various commercial sectors, including automotive, due to its durable, cost-effective, and environment-friendly characteristics. However, one of the limiting factors of biomass-based composites is its higher water absorption capacity compared to commercial synthetic composites. Therefore, this study aimed to optimize the water absorption capacity of biomass-based, wheat straw fiber-basalt hybrid composite brake pad using the Taguchi method by considering the particle size and volume % of the composite compositions. The composite synthesized in this study carried two variations of particle sizes of basalt, wheat straw, steel, river sand, and graphite, as well as two-volume percentages of epoxy resin for optimization. All composites were molded using a compression molding process at compressive pressure of 6 MPa for 2 h curing in a forced convection oven at 100 °C. Water absorption capacity has been determined according to ASTM D570. The wheat straw fiber has been chemically treated with 5 wt.% of sodium hydroxide (NaOH) to remove the impurities, lignin, and hemicellulose and increase the surface area of the fiber, resulting in a larger area of contact between the fiber and the matrix. Elemental analysis, crystallinity, morphology, and mechanical strength of wheat straw fiber-based composites have been determined by XRD, SEM, and compression tests, respectively. The statistical method, analysis of variance (ANOVA), was implemented for Taguchi optimization of the composite compositions. The maximum compressive strength and minimum and maximum water absorption capacity of composites were obtained as 77 MPa, 3.55%, and 26.86%, respectively. From the optimum setting of the confirmation experiment, the optimal water absorption value of 5.718% has been obtained. The optimum particle size of the composite compositions was 1 mm basalt particle, 0.5 mm wheat straw fiber, 1 mm steel particle, 1 mm river sand, 0.5 mm graphite dust particle, and 30 vol% epoxy resin by Taguchi method. The parameter impact of Taguchi ranking on water absorption capacity presented the maximum improvement of water absorption, 10.47%, with river sand particle size.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020062
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 63: Self-Sensing Eco-Earth Composite with
           Carbon Microfibers for Sustainable Smart Buildings

    • Authors: Hasan Borke Birgin, Antonella D’Alessandro, Andrea Meoni, Filippo Ubertini
      First page: 63
      Abstract: This paper proposes a new sustainable earth–cement building composite with multifunctional sensing features and investigates its properties through an experimental campaign. Earth and cement are proportioned as 2/7 in volume, while carbon microfibers are added in various amounts to achieve piezoresistivity, ranging from 0 to 1% with respect to the weight of the binder (i.e., earth + cement). The proposed material couples the construction performance with self-sensing properties in order to monitor the structural performance during the servile life of the building. The use of earth in the partial replacement of cement reduces the environmental footprint of the material while keeping sufficient mechanical properties, at least for applications that do not require a large load-bearing capacity (e.g., for plasters or for low-rise constructions). This paper analyzes the electrical and sensing behavior of cubic and beam samples through electrical and electromechanical tests. The results show that the samples with a filler percentage near the percolation zone, ranged between 0.025 and 0.25%, exhibit the best performance. From the cyclical compressive tests and linear developed models, it could be deduced that the filler content of 0.05% of carbon fibers, with respect to the binder weight, represents the best-performing smart composite for further investigation at higher scales. As demonstrated, the selected mix generated clear strain-sensing electrical signals, reaching gauge factors over 100.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020063
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 64: Recent Developments in Noble Metal-Free
           Catalysts for a Photocatalytic Water Splitting Process—A Review

    • Authors: Ama Dahanayake, Chamila A. Gunathilake, Achala Pallegedara, Piumal Jayasinghe
      First page: 64
      Abstract: Sustainable hydrogen production is an essential prerequisite of a future hydrogen economy. Compared to other processes such as renewable energy-driven water electrolysis and photoelectrochemical water splitting, direct solar to hydrogen conversion through photocatalytic water splitting gives the simplest system for sustainable hydrogen production. Among the many factors to be considered such as the availability of solar radiation, gas collection mechanism and other infrastructure, a highly active noble metal-free photocatalyst is essential to make the water splitting process more energy efficient and economical. This review highlights the mechanism and factors hindering the efficiency of catalysts in photocatalytic water splitting, while discussing recent research efforts towards the development of highly efficient, noble metal-free photocatalysts, especially at the nanoscale, and their catalytic properties for water splitting. Mainly, catalysts consisting of TiO2, Z-schemed catalytic systems and naval computational approaches are discussed here. Moreover, techniques to enhance their catalytic activities and the developments required for the implementation of these photocatalytic systems at a commercial scale are further emphasized in the discussion section.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020064
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 65: Manufacture and Characterization of
           Cola Lépidota Reinforcements for Composite Applications

    • Authors: Rémy Legrand Ndoumou, Damien Soulat, Ahmad Rashed Labanieh, Manuela Ferreira, Lucien Meva’a, Jean Atangana Ateba
      First page: 65
      Abstract: This study represents the first works on the manufacture of reinforcements for composite applications such as yarns and fabrics using a tropical fiber extracted from the bast of the Cola Lepidota (CL) plant. Different types of products were produced, including twisted and untwisted yarns and woven and quasi-unidirectional fabrics to manufacture composite samples. At each scale, experimental characterizations of textile and mechanical properties were carried out; these properties are compared to those given in the literature concerning natural fiber materials. The results show that the tenacity of twisted and untwisted CL yarns is higher than that of similar products based on flax fibers, which is an important result for the weaveability of these rovings. At the fabric scale, the quasi-unidirectional architecture reduces waviness and shows promising tensile properties compared to woven fabrics. On the scale of composites, these developments made it possible to achieve properties in tensile comparable, particularly in stiffness, to those achieved by composites based on natural fibers. The objectives of this paper are to highlight the advantages and drawbacks of different types of reinforcements, and to present the first characterization of the properties of products based on CL fibers.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020065
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 66: Micro-Scale Model of rCF/PA6 Spun Yarn

    • Authors: Tobias Georg Lang, Mir Mohammad Badrul Hasan, Anwar Abdkader, Chokri Cherif, Thomas Gereke
      First page: 66
      Abstract: Recycling carbon fibers (rCF) for reuse is one approach to improve the sustainability of CFRP. However, until now, recycled carbon fiber plastics (rCFRP) had limited composite properties due to the microgeometry of the fibers, which made it difficult to use in load-bearing components. The production of hybrid yarns from rCF and PA6 fibers allows the fibers to be aligned. The geometric properties of the yarn and the individual fibers influence the mechanical properties of the composite. An approach for the modeling and simulation of hybrid yarns consisting of recycled carbon fibers and thermoplastic fibers is presented. The yarn unit cell geometry is modeled in the form of a stochastic fiber network. The fiber trajectory is modeled in form of helical curves using the idealized yarn model of Hearle et al. The variability in the fiber geometry (e.g., length) is included in form of statistical distributions. An additional compaction step ensures a realistic composite geometry. The created model is validated geometrically and by comparison with tensile tests of manufactured composites. With the validated model, multiple parameter studies investigating the influence of fiber and yarn geometry are carried out.
      Citation: Journal of Composites Science
      PubDate: 2023-02-06
      DOI: 10.3390/jcs7020066
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 67: A Review on Concrete Composites
           Modified with Nanoparticles

    • Authors: Ghasan Fahim Huseien
      First page: 67
      Abstract: Recently, various nanomaterials have extensively been used to achieve sustainability goals in the construction sector. Thus, this paper presents a state-of-the-art review involving the uses of different nanomaterials for production of high-performance cementitious, geopolymer, and alkali-activated concrete composites. The effects of nanomaterials on the fresh properties, mechanical properties, and durability of diverse nanoparticle-modified concrete composites are analyzed. The past developments, recent trends, environmental impact, sustainability, notable benefits, and demerits of various nanomaterial-based concrete production are emphasized. It is demonstrated that nanomaterials including SiO2, Al2O3, TiO2, and Fe2O3, etc., can be used effectively to enhance the microstructures and mechanical characteristics (such as compressive strength, flexural, and splitting tensile strengths) of the modified concrete composites, thus improving their anti-erosion, anti-chloride penetration, and other durability traits. In short, this communication may provide deep insight into the role of diverse nanoparticle inclusion in concrete composites to improve their overall attributes.
      Citation: Journal of Composites Science
      PubDate: 2023-02-07
      DOI: 10.3390/jcs7020067
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 68: Effect of Fiber Side-Feeding on Various
           Properties of Nickel-Coated Carbon-Fiber-Reinforced Polyamide 6 Composites
           Prepared by a Twin-Screw Extrusion Process

    • Authors: Naeun Jeong, Donghwan Cho
      First page: 68
      Abstract: In the present study, how side-feeding of NiCF during twin-screw extrusion processing influences the fiber aspect ratio and thermal, mechanical, electrical, and electromagnetic properties of nickel-coated carbon fiber (NiCF)-reinforced polyamide 6 (PA6) composites was explored. For this, the fiber length distribution, thermal stability, heat deflection temperature, dynamic mechanical property, tensile, flexural, electrical resistivity, and electromagnetic interference shielding effectiveness (EMI SE) properties of NiCF/PA6 composites were extensively investigated. Chopped NiCF was regularly fed via either a main feeder or a side feeder and NiCF/PA6 pellets with different fiber-feeding pathways were prepared. The side-feeding effect of NiCF on the fiber length distribution and the composite properties was studied. The thermal stability, heat deflection temperature, storage modulus, tensile, flexural, and surface resistivity, and EMI SE properties of the NiCF/PA6 composites strongly depended not only on the NiCF content but also on the feeding method (main-feeding or side-feeding) upon extrusion processing, indicating that the fiber length distribution relevant to the fiber aspect ratio was critically important to enhance the composites’ properties. As a result, the NiCF/PA6 composites produced via side-feeding of NiCF exhibited an NiCF distribution longer than that produced via main-feeding, leading to enhancement of the thermal stability, heat deflection temperature, storage modulus, tensile, flexural, and EMI SE properties, strongly depending on the NiCF content.
      Citation: Journal of Composites Science
      PubDate: 2023-02-07
      DOI: 10.3390/jcs7020068
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 69: Cyclic Thermal Shock Response of
           Zirconia/304 Stainless Steel Functionally Graded Materials Fabricated by
           Centrifugal Slurry Methods

    • Authors: Hideaki Tsukamoto
      First page: 69
      Abstract: Functionally graded materials (FGMs) are multi-phase composites with gradual spatial variations of constituents. The compositional transitions in the FGMs are classified into two manners such as continuous gradient manners and stepwise manners. In this study, zirconia (ZrO2)/ 304 stainless steel (SUS304) FGMs with continuous gradient manners were fabricated by a combination of centrifugal slurry methods and spark plasma sintering (SPS). A variety of continuous gradient patterns were achieved by controlling the amount of dispersant such as ammonium polycarboxylic acid (PCA) in the slurry. With an increase in the amount of PCA, the gradient patterns in the FGMs changed from ceramic (ZrO2)-rich to metal (SUS304)-rich ones. According to Stokes sedimentation velocity simulations, the sedimentation velocity of SUS304 particles is higher than that of ZrO2 particles. With an increasing amount of PCA, the sedimentation velocity of the particles decreases. Cyclic thermal shock test results demonstrated that FGMs with metal (SUS304)-rich continuous gradient patterns showed the highest resistance among the samples of FGMs, 5-layered materials and ZrO2 single materials.
      Citation: Journal of Composites Science
      PubDate: 2023-02-07
      DOI: 10.3390/jcs7020069
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 70: The Effect of Metals of the 2nd and
           12th Groups on the Productivity and Selectivity of Cumene
           Oxidation—The First Stage of the Technological Chain for the
           Production of Polymer Composites

    • Authors: Nikolai V. Ulitin, Daria A. Shiyan, Yana L. Lyulinskaya, Nikolay A. Novikov, Konstantin A. Tereshchenko, Natalia M. Nurullina, Marina N. Denisova, Kharlampii E. Kharlampidi, Yaroslav O. Mezhuev
      First page: 70
      Abstract: The effect of the process temperature and the initial concentration of Mg, Ca, Sr, Ba, Zn, Cd, and Hg 2-ethylhexanoates as catalysts on the productivity and selectivity of the oxidation stage of cumene is studied in the technological chain for the production of polymer composites from cumene; “production of phenol by cumene method (stage 1 is cumene oxidation to cumene hydroperoxide, stage 2 is decomposition of cumene hydroperoxide into phenol and acetone) → production of precursors from phenol → production of polymers from precursors → production of composites from polymers”. A criterion has been introduced that reflects the productivity of cumene oxidation at the moment of reaching the maximum concentration of cumene hydroperoxide, which takes into account the cumene conversion and selectivity achieved in this case in the shortest possible time using the selectivity comparable with the selectivity of a non-catalytic process. It has been shown that the achievement of the maximum value of this criterion, among all the considered catalysts, is ensured by Mg 2-ethylhexanoate at its relatively low initial concentration (1 mmol/L) under conditions of moderately-high process temperatures (393–413 K).
      Citation: Journal of Composites Science
      PubDate: 2023-02-08
      DOI: 10.3390/jcs7020070
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 71: Formation of Composite Coatings during
           Detonation Spraying of Cr3C2

    • Authors: Igor S. Batraev, Vladimir Yu. Ulianitsky, Alexandr A. Shtertser, Dina V. Dudina, Arina V. Ukhina
      First page: 71
      Abstract: In the current practice of applying carbide-based coatings by thermal spraying, the starting material usually contains a metal binder. However, it is important to study the possibility of spraying binder-free carbides, since the metal components usually reduce the operating temperature and corrosion resistance of cermet coatings. In this work, a powder of chromium carbide, Cr3C2, was sprayed using a CCDS2000 detonation gun. Acetylene–oxygen mixtures C2H2 + kO2 with k varying from 0.8 to 3.0 were used as an energetic material. Due to chemical reactions between Cr3C2 and the detonation products, the coatings were of composite nature (multi-phase materials) with a composition depending on k. At k values in the range from 0.8 to 1.1, along with Cr3C2, the coatings contained chromium carbonitride Cr3N0.4C1.6. In the k range from 1.3 to 2.0, Cr7C3 and Cr were the main components of the coatings. As k was increased to 3.0, along with Cr7C3 and Cr, the CrO and Cr2O3 oxides formed in the coatings. The mechanical properties and wear resistance of the coatings were found to depend on their phase compositions. Coatings produced by detonation spraying of Cr3C2 powder may be useful for increasing the corrosion resistance of machine parts to mineral acids and high-temperature oxidation resistance.
      Citation: Journal of Composites Science
      PubDate: 2023-02-08
      DOI: 10.3390/jcs7020071
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 72: Influence of Natural Fiber Content on
           the Frictional Material of Brake Pads—A Review

    • Authors: Zeina Ammar, Hamdy Ibrahim, Mahmoud Adly, Ioannis Sarris, Sherif Mehanny
      First page: 72
      Abstract: Research into the use of eco-friendly materials, such as natural fibers, in brake pads has gained momentum in the last few decades. This can be attributed to the potential of natural fibers to replace traditional materials in tribological applications such as braking pads. The harmful impact of the commonly-used brake pad materials, such as metal and mineral fibers, on human health and the environment necessitates the development of eco-friendly alternatives. Natural fibers, such as banana peels, palm kernels, and palm slag, have been shown to be a viable replacement for traditional brake pad materials. This article reviews the literature on the use of different natural fibers in brake pads and their impact on the physical, mechanical, and tribological properties. Trends for density, porosity, hardness, coefficient of friction (COF), and wear rate are observed. The recommended formulations to yield the optimum properties, according to the perspective of several studies, are showcased. In addition, the effect of asbestos material and natural fibers on life-cycle assessment and CO2 emission is highlighted. This article is an attempt to provide a foundation for future researchers in the field of natural fiber-reinforced composites for brake pad applications.
      Citation: Journal of Composites Science
      PubDate: 2023-02-09
      DOI: 10.3390/jcs7020072
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 73: Impact Resistance Enhancement of
           Sustainable Geopolymer Composites Using High Volume Tile Ceramic Wastes

    • Authors: Ghasan Fahim Huseien, Ziyad Kubba, Akram M. Mhaya, Noshaba Hassan Malik, Jahangir Mirza
      First page: 73
      Abstract: The need for sustainable concrete with low carbon dioxide emissions and exceptional performance has recently increased in the building industry. Many distinct types of industrial byproducts and ecologically safe wastes have shown promise as ingredients for this kind of concrete. Meanwhile, as industrialization and lifestyle modernization continue to rise, ceramic waste becomes an increasingly serious threat to the natural environment. It is well known that free cement binder that incorporates tile ceramic wastes (TCWs) can significantly improve the material’s sustainability. We used this information to create a variety of geopolymer mortars by mixing TCWs with varied proportions of ground blast furnace slag (GBFS) and fly ash (FA). Analytical techniques were used to evaluate the mechanical properties and impact resistance (IR) of each designed mixture. TCWs were substituted for binders at percentages between 50 and 70 percent, and the resultant mixes were strong enough for real-world usage. Evidence suggests that the IR and ductility of the proposed mortars might be greatly improved by the addition of TCWs to a geopolymer matrix. It was found that there is a trend for both initial and failure impact energy to increase with increasing TCWs and FA content in the matrix. The results show that the raising of TCWs from 0% to 50, 60 and 70% significantly led to an increase in the failure impact energy from 397.3 J to 456.8, 496.6 and 595.9 J, respectively.
      Citation: Journal of Composites Science
      PubDate: 2023-02-09
      DOI: 10.3390/jcs7020073
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 74: Inductive Thermal Effect on
           Thermoplastic Nanocomposites with Magnetic Nanoparticles for
           Induced-Healing, Bonding and Debonding On-Demand Applications

    • Authors: Kanidi, Loura, Frengkou, Kosanovic Milickovic, Trompeta, Charitidis
      First page: 74
      Abstract: In this study, the heating capacity of nanocomposite materials enhanced with magnetic nanoparticles was investigated through induction heating. Thermoplastic (TP) matrices of polypropylene (PP), thermoplastic polyurethane (TPU), polyamide (PA12), and polyetherketoneketone (PEKK) were compounded with 2.5–10 wt.% iron oxide-based magnetic nanoparticles (MNPs) using a twin-screw extrusion system. Disk-shape specimens were prepared by 3D printing and injection molding. The heating capacity was examined as a function of exposure time, frequency, and power using a radio frequency (RF) generator with a solenoid inductor coil. All nanocomposite materials presented a temperature increase proportional to the MNPs’ concentration as a function of the exposure time in the magnetic field. The nanocomposites with a higher concentration of MNPs presented a rapid increase in temperature, resulting in polymer matrix melting in most of the trials. The operational parameters of the RF generator, such as the input power and the frequency, significantly affect the heating capacity of the specimens, higher input power, and higher frequencies and promote the rapid increase in temperature for all assessed nanocomposites, enabling induced-healing and bonding/debonding on-demand applications.
      Citation: Journal of Composites Science
      PubDate: 2023-02-09
      DOI: 10.3390/jcs7020074
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 75: Characterisation of Composite Materials
           for Wind Turbines Using Frequency Modulated Continuous Wave Sensing

    • Authors: Wenshuo Tang, Jamie Blanche, Daniel Mitchell, Samuel Harper, David Flynn
      First page: 75
      Abstract: Wind turbine blades (WTBs) are critical sub-systems consisting of composite multi-layer material structures. WTB inspection is a complex and labour intensive process, and failure of it can lead to substantial energy and economic losses to asset owners. In this paper, we proposed a novel non-destructive evaluation method for blade composite materials, which employs Frequency Modulated Continuous Wave (FMCW) radar, robotics and machine learning (ML) analytics. We show that using FMCW raster scan data, our ML algorithms (SVM, BP, Decision Tree and Naïve Bayes) can distinguish different types of composite materials with accuracy of over 97.5%. The best performance is achieved by SVM algorithms, with 94.3% accuracy. Furthermore, the proposed method can also achieve solid results for detecting surface defect: interlaminar porosity with 80% accuracy overall. In particular, the SVM classifier shows highest accuracy of 92.5% to 98.9%. We also show the ability to detect air voids of 1mm differences within the composite material WT structure with 94.1% accuracy performance using SVM, and 84.5% using Naïve Bayes. Lastly, we create a digital twin of the physical composite sample to support the integration and qualitative analysis of the FMCW data with respect to composite sample characteristics. The proposed method explores a new sensing modality for non-contact surface and subsurface for composite materials, and offer insights for developing alternative, more cost-effective inspection and maintenance regimes.
      Citation: Journal of Composites Science
      PubDate: 2023-02-10
      DOI: 10.3390/jcs7020075
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 76: Improved Fly Ash Based Structural Foam
           Concrete with Polypropylene Fiber

    • Authors: Alexey N. Beskopylny, Evgenii M. Shcherban’, Sergey A. Stel’makh, Levon R. Mailyan, Besarion Meskhi, Valery Varavka, Andrei Chernil’nik, Anastasia Pogrebnyak
      First page: 76
      Abstract: The direction of construction science that is associated with the development of the theory and practice of creating a new generation of foam concrete is particularly interesting and relevant. The development of improved structural foam concrete using polypropylene fiber and industrial waste, namely fly ash (FA), is prompted by the existing environmental threat posed by FA; this threat is a result of the operation of the fuel energy industry, as well as the possibility of using foam concrete not only as thermal insulation, but as the main material for load-bearing structures that have a certain level of responsibility. The aim of this work was to create and optimize the recipe technological parameters to produce non-autoclaved fiber foam concrete (FFC) using FA as a component. The study used standardized methods for assessing the properties of FFC, and the method of optical microscopy to analyze the structural characteristics of the material. It has been revealed that the replacement of cement with FA in an amount of 10% to 40% helps to reduce the dry density (DD) of FFC. The lowest DD was recorded for samples with 40% FA. The best results for the compressive strength (CS) and flexural strength (FS) were recorded for FFC samples with 10% FA instead of cement. The increase in CS was 12%, and the increase in FS was 23%. The best thermal insulation properties of FFC, and in terms of resistance to freezing and thawing, were recorded in samples with a 10% replacement of cement with FA. The maximum decrease in thermal conductivity was 14%.
      Citation: Journal of Composites Science
      PubDate: 2023-02-12
      DOI: 10.3390/jcs7020076
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 77: Progressive Review of Functional
           Nanomaterials-Based Polymer Nanocomposites for Efficient EMI Shielding

    • Authors: Prashanth Kallambadi Sadashivappa, Revathi Venkatachalam, Ramyakrishna Pothu, Rajender Boddula, Prasun Banerjee, Ramachandra Naik, Ahmed Bahgat Radwan, Noora Al-Qahtani
      First page: 77
      Abstract: Nanomaterials have assumed an imperative part in the advancement of human evolution and are more intertwined in our thinking and application. Contrary to the conventional micron-filled composites, the unique nanofillers often modify the properties of the polymer matrix at the same time, bestowing new functionality because of their chemical composition and their nano dimensions. The unprecedented technological revolution is driving people to adapt to miniaturized electronic gadgets. The sources of electromagnetic fields are ubiquitous in a tech-driven society. The COVID-19 pandemic has escalated the proliferation of electromagnetic interference as the world embraced remote working and content delivery over mobile communication devices. While EMI shielding is performed using the combination of reflection, absorption, and electrical and magnetic properties, under certain considerations, the dominant nature of any one of the properties may be required. The miniaturization of electronic gadgets coupled with wireless technologies is driving us to search for alternate lightweight EMI shielding materials with improved functionalities relative to conventional metals. Polymer nanocomposites have emerged as functional materials with versatile properties for EMI shielding. This paper reviews nanomaterials-based polymer nanocomposites for EMI shielding applications.
      Citation: Journal of Composites Science
      PubDate: 2023-02-13
      DOI: 10.3390/jcs7020077
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 78: Tension and Impact Analysis of Tungsten
           Inert Gas Welded Al6061-SiC Composite

    • Authors: P. K. Jayashree, Sathyashankara Sharma, Sourabh Kumar, Bhagyalaxmi Bhagyalaxmi, Mithesh Bangera, Ritesh Bhat
      First page: 78
      Abstract: An aluminum 6061 (Al6061) metal matrix composite (MMC) reinforced with silicon carbide was prepared by stir casting. Specimens of the required dimensions were welded using the tungsten inert gas (TIG) method. ER5356 (Al-5%Mg) was chosen as the appropriate filler material for TIG welding. The input current parameter was varied (150, 170 and 200nA) while maintaining the other welding parameters at constant values. An assessment of the mechanical (tensile and impact strength) and microstructure properties of the TIG-welded Al6061 MMC with 6 wt. % silicon carbide particles was accomplished. An 8.27% improvement was observed in ultimate tensile strength (UTS) for the 150 A TIG-welded sample. UTS and elasticity decreased linearly with an increase in welding current but exhibited higher values than in non-welded specimens. The microstructural analysis of the welded MMCs showed a mixed mode of failure, with equiaxial dimples being dominant in lower-weld-current specimens. Compared to non-welded specimens, a 40% increase in impact strength was observed for the 150 A TIG-welded specimens, which decreased with an increase in the welding current value. SEM analysis revealed ductile striations and continuous river patterns, resulting in mixed failure.
      Citation: Journal of Composites Science
      PubDate: 2023-02-14
      DOI: 10.3390/jcs7020078
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 79: The Importance of Water for
           Purification of Longer Carbon Nanotubes for Nanocomposite Applications

    • Authors: Vladimir Z. Mordkovich, Maxim A. Khaskov, Veronika A. Naumova, Victor V. De, Boris A. Kulnitskiy, Aida R. Karaeva
      First page: 79
      Abstract: Ultralong carbon nanotubes (UCNTs) are in high demand for nanocomposites applications due to their magnificent physical and chemical properties. UCNTs are synthesized by the catalytic chemical vapor deposition (CCVD) method and, before use as fillers in nanocomposites, should be purified of residual catalyst and non-CNT particles without significant destruction or scissoring of the UCNT. This study investigates the role of water vapor for purification of UCNTs from iron catalyst particles and the importance of water assistance in this process is confirmed. It was shown that wet air treatment of products of UCNTs CCVD synthesis under mild conditions can be used to sufficiently decrease residual iron catalyst content without significant carbon losses in comparison to the results obtained with dry air, while the residual iron content was shown to significantly influence the subsequent oxidation of different forms of carbons, including UCNTs. The increasing of D/G ratio of Raman spectra after wet air treatment of products of UCNTs CCVD synthesis makes it possible to conclude that iron catalyst particles transform into iron oxides and hydroxides that caused inner structural strains and destruction of carbon shells, improving removal of the catalyst particles by subsequent acid treatment. UCNTs purification with water assistance can be used to develop economically and ecologically friendly methods for obtaining fillers for nanocomposites of different applications.
      Citation: Journal of Composites Science
      PubDate: 2023-02-15
      DOI: 10.3390/jcs7020079
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 80: 3D Printing of Dental Prostheses:
           Current and Emerging Applications

    • Authors: Fereshte Rezaie, Masoud Farshbaf, Mohammad Dahri, Moein Masjedi, Reza Maleki, Fatemeh Amini, Jonathan Wirth, Keyvan Moharamzadeh, Franz E. Weber, Lobat Tayebi
      First page: 80
      Abstract: Revolutionary fabrication technologies such as three-dimensional (3D) printing to develop dental structures are expected to replace traditional methods due to their ability to establish constructs with the required mechanical properties and detailed structures. Three-dimensional printing, as an additive manufacturing approach, has the potential to rapidly fabricate complex dental prostheses by employing a bottom-up strategy in a layer-by-layer fashion. This new technology allows dentists to extend their degree of freedom in selecting, creating, and performing the required treatments. Three-dimensional printing has been narrowly employed in the fabrication of various kinds of prostheses and implants. There is still an on-demand production procedure that offers a reasonable method with superior efficiency to engineer multifaceted dental constructs. This review article aims to cover the most recent applications of 3D printing techniques in the manufacturing of dental prosthetics. More specifically, after describing various 3D printing techniques and their advantages/disadvantages, the applications of 3D printing in dental prostheses are elaborated in various examples in the literature. Different 3D printing techniques have the capability to use different materials, including thermoplastic polymers, ceramics, and metals with distinctive suitability for dental applications, which are discussed in this article. The relevant limitations and challenges that currently limit the efficacy of 3D printing in this field are also reviewed. This review article has employed five major scientific databases, including Google Scholar, PubMed, ScienceDirect, Web of Science, and Scopus, with appropriate keywords to find the most relevant literature in the subject of dental prostheses 3D printing.
      Citation: Journal of Composites Science
      PubDate: 2023-02-15
      DOI: 10.3390/jcs7020080
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 81: Organomorphic Silicon Carbide
           Reinforcing Preform Formation Mechanism

    • Authors: Evgeny Bogachev
      First page: 81
      Abstract: Development of the organomorphic ceramic-matrix composites (CMCs), where the reinforcing preform is built using polymer fibers subject essentially to hot pressing, was motivated by a desire to obtain much higher structural uniformity as well as to reduce the number of the process steps involved in the production of CMCs. This paper addresses the peculiarities of the organomorphic silicon carbide preform formation process. Using X-ray phase analysis, tomography, mass and IR spectroscopy, and thermomechanical and X-ray microanalysis, both the properties of the initial fibers of polycarbosilane (PCS)—the silicon carbide fiber precursor—and their transformation in the preform while heated to 1250 °C under constant pressing at 10–100 kPa were studied. Analysis of the data obtained showed the organomorphic SiC preform relative density at a level of 0.3–0.4 to be ensured by self-bonding of the silicon carbide preform, resulting from the fact that during the low-temperature part of pyrolysis, easily polymerizing substances are released leaving a high coke residue, thus cementing the preform. Another possible factor of SiC framework self-bonding is the destruction of the polymer fibers during pyrolysis of various PCS preforms differing in their methylsilane composition (for example, dimethylsilane), where deposition of silicon carbide on the contacting fibers starts as early as at 450–500 °C.
      Citation: Journal of Composites Science
      PubDate: 2023-02-15
      DOI: 10.3390/jcs7020081
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 82: Cool-Clave—An Energy
           Efficient Autoclave

    • Authors: Indraneel R. Chowdhury, John Summerscales
      First page: 82
      Abstract: Out-of-autoclave (OOA) manufacturing techniques for composites result in lower fibre volume fractions than for fully compressed laminates. The lower fibre volume fraction produces a higher resin volume fraction, which becomes resin-rich volumes (RRV). Textile reinforcements with clustered fibres and consequent RRV generally have low strength but high in-plane process permeability, whereas the opposite is true for uniformly distributed fibres. The inevitable increase in resin volume fraction of OOA composites often compromises composite performance and leads to relatively higher weight and fuel consumption in transport applications. The retention of autoclave processing is recommended for highest performance when compression press moulding is not appropriate (for example, for complex 3D components). The traditional autoclave processing of composites heats not only the component to be cured but also parasitic air and the vessel insulation. Subject to minor modifications of the pressure vessel, electrically heated tooling could be implemented. This approach would need to balance insulation of the heated tool surface (and any heater blanket on the counter-face) against the quenching effect during the introduction of the pressurised cool air. This process optimisation would significantly reduce energy consumption. Additionally, the laminate on the heated tool could be taken to the end of the dwell period before loading the autoclave, leading to significant reductions in cure cycle times. Components could be cured simultaneously at different temperatures provided that there are sufficient power and control circuits in the autoclave. While autoclave processing has usually involved vacuum-bagged pre-impregnated reinforcements, implementation of the cool-clave technique could also provide a scope for using the pressure vessel to cure vacuum-infused composites.
      Citation: Journal of Composites Science
      PubDate: 2023-02-16
      DOI: 10.3390/jcs7020082
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 83: Investigation on Layer Hybridization of
           Glass/Carbon Fibre Woven Reinforced Composites Subjected to Low-Speed

    • Authors: Raluca Maier, Andrei-Cristian Mandoc
      First page: 83
      Abstract: The present investigation was conducted on the low-speed impact response of quasi-isotropic [±45/0/90°]xs hybrid composite through laboratory level experimental tests. The purpose was to understand the behaviour that the different stacking sequences of hybrid glass/carbon fibre composites has on the ability of the material to sustain loads during low-speed impact events without developing critical structural failure in the material and improving the impact energy absorption properties, which is a relevant matter in aerospace and automotive industries. Drop-weight impact tests were carried out on two different laminates, with different stacking sequences, each of which were 16 symmetric inter-ply hybrid laminates named GC [+45G/−45C/0G/90C]4s and, respectively, G-C [+45G/−45G/0G/90G/+45C/−45C/0C/90C]2s, where G stands for glass fibre and C for carbon fibre. Both were comprised of epoxy matrix reinforced carbon/E-glass fibre woven fabric composites. The outcome of changing the hybrid stacking sequence, on the impact performances, was discussed. The damage morphologies and local failure mechanisms were analysed using visual inspection and a high-resolution laser scanner. Under 33 J impact energy, both tested hybrid composites exhibited approximately 10 kN peak load. Nevertheless, one key parameter, the time to peak load, significantly changed; the damage initiation threshold for GC samples occurred immediately before 6 kN, whereas for G-C samples this threshold appeared much earlier. This type of behaviour was partly connected to the delay in the propagation of delamination and fibre breakage, which was influenced by the high elastic energy absorption of the carbon fibres when compared with the glass fibres. The absorbed energy was higher for GC configuration, whereas a higher DI was observed for samples G-C indicating that a high percentage of the total energy was dissipated through the propagation of in-plane and out-of-plane fibre/matrix cracks. No perforation was observed on either configuration; nevertheless, the damage area significantly changed both in size and appearance from one configuration to another.
      Citation: Journal of Composites Science
      PubDate: 2023-02-16
      DOI: 10.3390/jcs7020083
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 84: Heavy Metal Removal from Aqueous
           Solutions Using Biomaterials and/or Functional Composites: Recent Advances
           and the Way Forward in Wastewater Treatment Using Digitalization

    • Authors: Tonni Agustiono Kurniawan, Wai-Hung Lo, Xue Liang, Hui Hwang Goh, Mohd Hafiz Dzarfan Othman, Kok-Keong Chong, Ayesha Mohyuddin, Axel Olaf Kern, Kit Wayne Chew
      First page: 84
      Abstract: Due to its low cost, over the past decades, biosorption technology has been extensively carried out to treat heavy metal-laden wastewater using biosorbents. Recent studies on heavy metal biosorption mechanisms and the simulation of mathematical modeling on the biosorption process have enhanced scientific understanding about the binding between target metal cations and the functional group on different surfaces of biomasses as a biosorbent. However, so far, none have provided an overview of mechanistic studies on heavy metal removal from aqueous solutions using inexpensive biosorbents. To close this knowledge gap, this article discusses the applicability of the surface complexation (SC) model for biosorption of a target pollutant. Insightful ideas and directions of future research in wastewater treatment using digital technologies are also presented. It was conclusive from a literature survey of 115 articles (1987–2023) that Aspergillus niger, Penicillium chrysogenum, and Rhizopus nigricans represent biomaterials that have substantial adsorption capacities, up to 200 mg of Au(I)/g, 142 mg of Th/g, and 166 mg of Pb(II)/g, respectively. The metal-binding mechanisms involved include ion exchange, surface complexation, and micro-precipitation. Ion exchange is the only mechanisms that play key roles in sequestering heavy metal using fungal cells with chitin and chitosan. X-ray energy dispersion (XED) and scanning electron microscopy (SEM) analysis were used to evaluate biosorption mechanisms of the inorganic pollutants using physico-chemical characterization on the cell surfaces of the biomass. As metal removal by the biosorbent is affected by its surface properties, surface complexation also occurs. The affinity of the surface complexation depends on the type of functional groups such as phosphate, carboxyl, and amine.
      Citation: Journal of Composites Science
      PubDate: 2023-02-16
      DOI: 10.3390/jcs7020084
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 85: Preparation and Properties of
           Flame-Retardant Polyurethane Pressure Sensitive Adhesive and Its

    • Authors: Lijuan Zeng, Liu Yang, Junbang Liu, Shangkai Lu, Lianghui Ai, Yang Dong, Zhibin Ye, Ping Liu
      First page: 85
      Abstract: Using 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxo-10-phosphine-10-oxide (DOPO-H Q), N,N-diethyl-bis(hydroxyethyl) aminomethylene phosphate diethyl (FRC-6), and (6-oxo- 6H-dibenzo[c,e][1,2]oxphosphine-6-yl) hydroxylmethyl-thiophene (DOPO-SF) as reactive flame retardants, the flame-retardant polyurethane pressure sensitive adhesive (FRPU-PSA) were prepared. The fourier transform infrared (FTIR), thermogravimetric analysis (TG), limiting oxygen index (LOI), vertical combustion (UL 94), 180° peeling, and inclined ball rolling were used to characterize and investigate the properties of FRPU-PSA. It was found that the LOI of PU/50mol%DOPO-HQ, PU/50mol%FRC-6, and PU/20wt%DOPO-SF were 30.7%, 29.3%, and 25.0%, respectively, the peel strength of PU/50mol%DOPO-HQ and PU/50mol%FRC-6 were 3.88N/25 mm and 3.42N/25 mm, respectively. FRPU-PSA not only had good bond strength, but also had good flame retardant performance.
      Citation: Journal of Composites Science
      PubDate: 2023-02-16
      DOI: 10.3390/jcs7020085
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 86: Biomedical Applications of Blow-Spun
           Coatings, Mats, and Scaffolds—A Mini-Review

    • Authors: Mohammadmahdi Mobaraki, Meichen Liu, Abdul-Razak Masoud, David K. Mills
      First page: 86
      Abstract: Human tissues and disease models require well-defined biomimetic microenvironments. During the past decade, innovative developments in materials science, microfabrication, and polymer science have provided us with the ability to manipulate cellular microenvironments for regenerative medicine and tissue engineering applications. Solution blow spinning is a facile fiber fabricating method that requires a simple apparatus, a concentrated polymer solution within a volatile solvent, and a high-pressure gas source. Commercially available airbrushes, typically used for painting and cosmetic makeup, have successfully generated a range of nanofibers and films. Applications under investigation are similar to electrospinning and include enzyme immobilization, drug delivery, filtration, infection protection, tissue engineering, and wound healing. This review will discuss fiber fabrication methods before a more detailed discussion of the potential of blow-spinning in biomedical applications.
      Citation: Journal of Composites Science
      PubDate: 2023-02-17
      DOI: 10.3390/jcs7020086
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 87: Static and Dynamic Analysis of Linear
           Piezoelectric Structures Using Higher Order Shear Deformation Theories

    • Authors: Konstantinos I. Ntaflos, Konstantinos G. Beltsios, Evangelos P. Hadjigeorgiou
      First page: 87
      Abstract: This paper explores the effects of shear deformation on piezoelectric materials and structures that often serve as substrate layers of multilayer composite sensors and actuators. Based on higher-order shear elastic deformation and electric potential distribution theories, a general mathematical model is derived. Governing equations and the associated boundary conditions for a piezoelectric beam are developed using a generalized Hamilton’s principle. The static and dynamic behavior of the piezoelectric structure is investigated. A bending problem in static analysis and a free vibration problem in dynamic analysis are solved. The obtained results are in very good agreement with the results of the exact two dimensional solution available in the literature.
      Citation: Journal of Composites Science
      PubDate: 2023-02-17
      DOI: 10.3390/jcs7020087
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 88: The Effect of Pulse Current on
           Electrolytically Plating Nickel as a Catalyst for Grafting Carbon
           Nanotubes onto Carbon Fibers via the Chemical Vapor Deposition Method

    • Authors: Kazuto Tanaka, Shuhei Kyoyama
      First page: 88
      Abstract: Carbon nanotubes (CNTs) can be directly grafted onto the surface of carbon fibers using the chemical vapor deposition method, in which nanometer-order nickel (Ni) particles, serving as catalysts, are plated onto the surface of carbon fibers via electrolytic plating. In our previous studies, in which a direct current (DC) was used to electrolytically plate Ni onto carbon fibers as a catalyst, the site densities and diameters of Ni particles increased simultaneously with the plating time, making it difficult to independently control the site densities and diameters of the particles. On the other hand, pulse current (PC) plating is attracting attention as a plating technique that can control the deposition morphology of nuclei. In this study, we clarify the effect of the parameters of the PC on the particle number per unit area (site density) and the particle diameters of Ni particles plated onto the surface of carbon fibers, using the PC to electrolytically plate Ni. Electrolytically plating Ni onto carbon fibers (via PC) after the removal of the sizing agent enable Ni particles with sparser site densities and larger diameters to be plated than those plated via DC. Using Ni particles with sparse site densities, it is shown that CNTs with sparse site densities can be grafted.
      Citation: Journal of Composites Science
      PubDate: 2023-02-19
      DOI: 10.3390/jcs7020088
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 89: Characterization of UV Light Curable
           Piezoelectric 0-0-3 Composites Filled with Lead-Free Ceramics and
           Conductive Nanoparticles

    • Authors: Rytis Mitkus, Lena Piechowiak, Michael Sinapius
      First page: 89
      Abstract: Lead-free piezoelectric materials are essential for our healthy future but offer lower performance than lead-based materials. Different material combinations are explored to improve the performance of lead-free materials. By filling the UV light curable photopolymer resin with 30 vol.% lead-free piezoelectric ceramics and with up to 0.4 wt.% conductive nanofillers, thin and flexible piezoelectric 0-0-3 composites are formed. Two particle sizes of Potassium Sodium Niobate (KNN) and Barium Titanate (BTO) ceramics were used with four conductive nanofillers: Graphene Nanoplatelets (GNPs), Multi-Walled Carbon Nanotubes (MWCNTs), and two types of Graphene Oxide (GO). Resulting high viscosity suspensions are tape-cast in a mold as thin layers and subsequently exposing them to UV light, piezoelectric composite sensors are formed in 80 s. Even low nanofiller concentrations increase relative permittivities, however, they strongly reduce curing depth and increase undesirable dielectric losses. Non-homogeneous dispersion of nanofillers is observed. In total, 36 different compositions were mixed and characterized. Only six selected material compositions were investigated further by measuring mechanical, dielectric, and piezoelectric properties. Results show KNN composite performance as piezoelectric sensors is almost six times higher than BTO composite performance.
      Citation: Journal of Composites Science
      PubDate: 2023-02-20
      DOI: 10.3390/jcs7020089
      Issue No: Vol. 7, No. 2 (2023)
  • J. Compos. Sci., Vol. 7, Pages 27: Mechanical Properties of PLA Specimens
           Obtained by Additive Manufacturing Process Reinforced with Flax Fibers

    • Authors: Ana Paulo, Jorge Santos, João da Rocha, Rui Lima, João Ribeiro
      First page: 27
      Abstract: Although polylactic acid (PLA) is one of the most used materials in additive manufacturing, its mechanical properties are quite limiting for its practical application, therefore, to improve these properties it is frequent to add fibers and, in this way, create a more resistant composite material. In this paper, the authors developed PLA composites reinforced with flax fibers to evaluate the improvement of tensile and flexural strength. The experimental design of experiments was based on the L18 Taguchi array where the control factors were the extruder temperature (three levels), number of strands (three levels), infill percentage of the specimens (three levels), and whether the flax fiber had surface chemical treatment. The tensile and flexural specimens were made on a 3D printing machine and was a mold was developed to fix and align the fiber strands during the printing process. The tensile and flexural experimental tests were performed in agreement with ASTM D638.14 and ISO 14125 standards, respectively. Analyzing the results, it was verified that the surface chemical treatment (NaOH) of the fiber did not show any influence in the mechanical properties of the composites; in contrast, the infill density demonstrated a huge influence for the improvement of mechanical strength. The maximum values of tensile and bending stress were 50 MPa and 73 MPa, respectively. The natural fiber reinforcement can improve the mechanical properties of the PLA composites.
      Citation: Journal of Composites Science
      PubDate: 2023-01-10
      DOI: 10.3390/jcs7010027
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 28: Critical Influences of Plasma pH on
           Human Protein Properties for Modeling Considerations: Size, Charge,
           Conformation, Hydrophobicity, and Denaturation

    • Authors: Majak Mapiour, Abdelrasoul Amira
      First page: 28
      Abstract: The fouling of biomaterials (e.g., membranes) by plasma proteins has always garnered attention because it renders biomedical devices ineffective and can jeopardize the patient’s well-being. Modeling the fouling process sheds light on its mechanisms and helps improve the biocompatibility of biomaterials. Assuming proteins to be hard spheres with uniform surface properties reduces the modeling complexity, but it seriously deviates from the accurate, real perspective. One reason for the inaccuracy is that proteins’ properties tend to change as environmental factors such as pH and ionic strength are varied. This study critically reviews the pH-induced changes in protein properties, namely size, charge, conformity, hydrophobicity, and denaturation. Though these properties may be interrelated, they are addressed individually to allow for a thorough discussion. The study illustrates the necessity of incorporating the protein property changes resulting from pH alteration to better explain and model the fouling process. The discussion is focused on human serum albumin and fibrinogen. Human serum albumin is the most abundant plasma protein, while fibrinogen plays a major role in blood clotting and triggering of the thrombogenic response.
      Citation: Journal of Composites Science
      PubDate: 2023-01-10
      DOI: 10.3390/jcs7010028
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 29: Mechanical Homogenization of
           Transversely Isotropic CNT/GNP Reinforced Biocomposite for Wind Turbine
           Blades: Numerical and Analytical Study

    • Authors: Amine El Bahi, Marwane Rouway, Mostapha Tarfaoui, Ahmed El Moumen, Nabil Chakhchaoui, Omar Cherkaoui, Lhaj El Hachemi Omari
      First page: 29
      Abstract: One of the biggest problems facing the use of carbon nanotubes in reinforced composites is agglomeration within the matrix phase. This phenomenon—caused by Van der Waals forces—leads to dispersion problems and weakens the properties of the composites. This research presents a multi-stage homogenization approach used to investigate the influence of the aspect ratio, volume fraction, and agglomeration of the nanofillers on the effective mechanical properties of a polymer biocomposite containing randomly dispersed carbon nanotubes and graphene nanoplatelets. The first stage consisted in evaluating the properties of the reinforced polymers by the CNT/GNP. The second step consisted in combining the reinforced polymers with different natural and synthetic unidirectionally oriented fibers. It was found that agglomeration has a huge influence on the mechanical properties of the composite. The novelty of this work consisted of the consideration of the parameters influencing the elastic properties using different micromechanics approaches and numerical techniques.
      Citation: Journal of Composites Science
      PubDate: 2023-01-10
      DOI: 10.3390/jcs7010029
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 30: Simplified Approach to Nonlinear
           Vibration Analysis of Variable Stiffness Plates

    • Authors: Jorge Andérez González, Riccardo Vescovini
      First page: 30
      Abstract: A formulation for the analysis of the nonlinear vibrations of Variable Stiffness (VS) plates is presented. Third-order Shear Deformation Theory (TSDT) is employed in conjunction with a mixed variational formulation. The solution is sought via Ritz approximation for the spatial dependency, while time dependency is handled via Differential Quadrature (DQ) and Harmonic Balance (HB) methods. The main advantage of the framework is the reduced computational time, which is of particular interest to explore the large design space offered by variable stiffness configurations. The results are validated against reference solutions from the literature. Exemplary parametric studies are presented to demonstrate the potential of the approach as a powerful means for exploring the nonlinear vibration response of VS plates.
      Citation: Journal of Composites Science
      PubDate: 2023-01-10
      DOI: 10.3390/jcs7010030
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 31: Impact Resistant Flax Fiber Fabrics
           Using Shear Thickening Fluid

    • Authors: Joseph Fehrenbach, Eric Hall, Luke Gibbon, Tanner Smith, Ali Amiri, Chad Ulven
      First page: 31
      Abstract: Shear thickening fluids (STFs) have been shown to improve the effectiveness of fabrics used in soft body armor applications. They are used to increase the puncture and ballistic impact resistance of Kevlar® fabrics. However, the effect of using STFs with natural fabrics such as flax appears to have never been studied. Similarly, the hybridization of different fabric types impregnated with STF has also only undergone limited study. The rheology of STFs at varying concentrations of nanosilica dispersed in polyethylene glycol (PEG) was studied at different temperatures. It was found that the STFs behave as a non-Newtonian fluid in response to changes in shear rate. In this study the effectiveness on the puncture and ballistic impact resistance of impregnating flax fabric with STF at concentrations of 30%, 50%, and 70% w/w of nanosilica in PEG was investigated. The effect of hybridization of flax and Kevlar® fabrics impregnated with STF was also investigated. The puncture resistance of both flax fabrics treated with STFs and hybrids treated with STFs was found to increase significantly and can be controlled by STF concentration. The ballistic impact resistance was also found to increase in the hybrid samples when STF concentration was at least 50%. The flax treated with STFs showed either a decrease in specific energy absorption per layer for the lower STF concentration, or a very small increase at 70% STF concentration.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010031
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 32: Design, Simulation, and Mechanical
           Testing of 3D-Printed Titanium Lattice Structures

    • Authors: Klaudio Bari
      First page: 32
      Abstract: Lattice structure topology is a rapidly growing area of research facilitated by developments in additive manufacturing. These low-density structures are particularly promising for their medical applications. However, predicting their performance becomes a challenging factor in their use. In this article, four lattice topologies are explored for their suitability as implants for the replacement of segmental bone defects. The study introduces a unit-cell concept for designing and manufacturing four lattice structures, BCC, FCC, AUX, and ORG, using direct melt laser sintering (DMLS). The elastic modulus was assessed using an axial compression strength test and validated using linear static FEA simulation. The outcomes of the simulation revealed the disparity between the unit cell and the entire lattice in the cases of BCC, FCC, and AUX, while the unit-cell concept of the full lattice structure was successful in ORG. Measurements of energy absorption obtained from the compression testing revealed that the ORG lattice had the highest absorbed energy (350 J) compared with the others. The observed failure modes indicated a sudden collapsing pattern during the compression test in the cases of BCC and FCC designs, while our inspired ORG and AUX lattices outperformed the others in terms of their structural integrity under identical loading conditions.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010032
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 33: Dynamic Composite Materials
           Characterisation with Hopkinson Bars: Design and Development of New
           Dynamic Compression Systems

    • Authors: Mostapha Tarfaoui
      First page: 33
      Abstract: The split Hopkinson pressure bars (SHPB) system is the most commonly employed machine to study the dynamic characteristics of different materials under high strain rates. In this research, a numerical investigation is carried out to study different bar shapes such as square, hexagonal, and triangular cross-sections and to compare them with the standard cylindrical bars. The 3D finite element model developed for circular cross-sectional shapes was first validated with the experimental results and then compared with the other proposed shapes. In most scientific research, cylindrical cross-section bars with a square cross-section specimen are traditionally used as they have several advantages, such as in situ imaging of the side surfaces of the specimen during stress wave propagation. Moreover, the flat surfaces of the proposed shapes counter the problem of debonding strain gauges, especially at high impact pressures. Comparison of the results showed an excellent confirmation of the sample dynamic behaviour and different geometric shapes of the bar geometries, which validates the choice of the appropriate system.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010033
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 34: Improved Wear and Corrosion Resistance
           in TiC-Reinforced SUS304 Stainless Steel

    • Authors: Chieh-Jung Lu, Jien-Wei Yeh
      First page: 34
      Abstract: Herein, the vacuum arc-melting process is applied to incorporate various amounts of Ti and C into SUS304 austenitic stainless steel based on the high-entropy alloy concept to obtain wear- and corrosion-resistant alloys with in situ carbide reinforcements. Five compositions containing the equivalent of 5, 10, 15, 20, and 25 volume percentages of TiC in SUS304 stainless steel, named A1, A2, A3, A4, and A5, respectively, were designed, melted, and solidified by the arc-melting method. Microstructural analyses, hardness measurements, immersion tests in four corrosive solutions, electrochemical measurements in a 3.5 wt % NaCl(aq) solution, and tribological tests were conducted to determine the properties and explain the relevant mechanisms. A1 exhibited a eutectic structure between FCC dendrites, while A2, A3, A4, and A5 possessed proeutectic dendritic TiC, FCC dendrites enveloping the TiC dendrites, and a eutectic structure. A5 represents the optimal composition. Its hardness, wear resistance, and corrosion resistance are 2, 14, and 4 times higher than those of SUS304, respectively. Additionally, its wear resistance is 2.5 times that of high-chromium cast iron. Consequently, A5 could have a 2.5-fold longer lifetime in wear operation. Therefore, A5 could be potentially applied in corrosive and abrasive environments, such as rotary shafts, rotors, bearings, and structural parts in food, chemical, and optoelectronic industries.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010034
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 35: Sustainable Composites from Waste
           Sulfur, Terpenoids, and Pozzolan Cements

    • Authors: Katelyn A. Tisdale, Charini P. Maladeniya, Claudia V. Lopez, Andrew G. Tennyson, Rhett C. Smith
      First page: 35
      Abstract: Sulfur cements have drawn significant attention as binders because sulfur is a byproduct of fossil fuel refining. Sulfur cements that can be formed by the vulcanization of elemental sulfur and plant-derived olefins such as terpenoids are particularly promising from a sustainability standpoint. A range of terpenoid–sulfur cements have shown compressional and flexural properties exceeding those of some commercial structural mineral cements. Pozzolans such as fly ash (FA), silica fume (SF), and ground granulated blast furnace slag (GGBFS) and abundant clay resources such as metakaolin (MK) are attractive fines for addition to binders. Herein, we report 10 composites prepared by a combination of sulfur, terpenoids (geraniol or citronellol), and these pozzolans. This study reveals the extent to which the addition of the pozzolan fines to the sulfur–terpenoid cements influences their mechanical properties and chemical resistance. The sulfur–terpenoid composites CitS and GerS were prepared by the reaction of 90 wt% sulfur and 10 wt% citronellol or geraniol oil, respectively. The density of the composites fell within the range of 1800–1900 kg/m3 and after 24 h submersion in water at room temperature, none of the materials absorbed more than 0.7 wt% water. The compressional strength of the as-prepared materials ranged from 9.1–23.2 MPa, and the percentage of compressional strength retained after acid challenge (submersion in 0.1 M H2SO4 for 24 h) ranged from 80–100%. Incorporating pozzolan fines into the already strong CitS (18.8 MPa) had negligible effects on its compressional strength within the statistical error of the measurement. CitS-SF and CitS-MK had slightly higher compressive strengths of 20.4 MPa and 23.2 MPa, respectively. CitS-GGBFS and CitS-FA resulted in slightly lower compressive strengths of 17.0 MPa and 15.8 MPa, respectively. In contrast, the compressional strength of initially softer GerS (11.7 MPa) benefited greatly after incorporating hard mineral fines. All GerS derivatives had higher compressive strengths than GerS, with GerS-MK having the highest compressive strength of 19.8 MPa. The compressional strengths of several of the composites compare favorably to those required by traditional mineral cements for residential building foundations (17 MPa), whereas such mineral products disintegrate upon similar acid challenge.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010035
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 36: Effect of Compatibilizer and Organoclay
           Reinforcement on Morphology and Properties of Styrene Copolymer Blends

    • Authors: Marianna Triantou, Marios Gavriel, Petroula A. Tarantili
      First page: 36
      Abstract: The blending of polymers leads to materials with the desired combined properties. These properties can further be improved by the incorporation of compatibilizer, organoclay, or both. In the present manuscript, the effects of compatibilizer and organoclay, as well as their combined use on the rheological, thermal, and mechanical properties of styrene copolymer blends, is examined. Styrene-containing copolymers blends were prepared by melt-mixing in a twin screw extruder. The addition of SAN into ABS decreases its thermal stability, whereas it increases its tensile strength and modulus. The incorporation of organoclay in ABS/SAN blends increases their viscosity and slightly improves their thermal stability and significantly improves the tensile and storage moduli. In PC/SAN blends, the SAN copolymer increases the flow rate, as well as the tensile strength and modulus of PC, whereas it decreases the thermal stability. The addition of ABS-g-MAH compatibilizer in PC/SAN blends increases the melt viscosity and maximum decomposition rate temperature of SAN phase, while it leads to the earlier decomposition of the PC phase. The incorporation of organoclay reinforcement enhances the thermal decomposition resistance of thes SAN phase. The opposite effect was recorded for the PC phase. The addition of organoclay enhances the elastic modulus of PC/SAN hybrids.
      Citation: Journal of Composites Science
      PubDate: 2023-01-11
      DOI: 10.3390/jcs7010036
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 37: Study of the Effects of Alkali
           Treatment and Fiber Orientation on Mechanical Properties of Enset/Sisal
           Polymer Hybrid Composite

    • Authors: Abera E. Bekele, Hirpa G. Lemu, Moera G. Jiru
      First page: 37
      Abstract: In the manufacturing process of innovative fiber-based composite materials, natural fibers are among the most commonly employed reinforcements. In this study, Enset/Sisal (E/S) fiber with a polyester matrix was used to develop the hybrid composites. Hand layup methods were employed for the sample preparation from untreated, 5%, and 10% alkali-treated unidirectional and woven fiber orientations having 50:50 volume ratios. The mechanical properties and water absorption of natural fiber hybrid composites were influenced by fiber treatment and orientation. In the present investigation, the result shows that treated and woven fiber orientation hybrid composites exhibit better mechanical properties than untreated and unidirectional E/S hybrid composites. The 5% NaOH-treated samples have higher tensile and flexural strength properties than the untreated and 10% alkali-treated composites, while the 5% NaOH-treated fiber composites have lower water absorption properties. The tensile and flexural strengths and impacts of 5% NaOH-treated composites were improved by 5.21%, 9.25%, and 5.98%, respectively, over untreated E/S hybrid composites. The morphological properties of the fracture surface of the composite were observed using scanning electron microscopy (SEM).
      Citation: Journal of Composites Science
      PubDate: 2023-01-12
      DOI: 10.3390/jcs7010037
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 38: Microstructural Analysis of the
           Transverse and Shear Behavior of Additively Manufactured CFRP Composite
           RVEs Based on the Phase-Field Fracture Theory

    • Authors: Matej Gljušćić, Domagoj Lanc, Marina Franulović, Andrej Žerovnik
      First page: 38
      Abstract: Due to the versatility of its implementation, additive manufacturing has become the enabling technology in the research and development of innovative engineering components. However, many experimental studies have shown inconsistent results and have highlighted multiple defects in the materials’ structure thus bringing the adoption of the additive manufacturing method in practical engineering applications into question, yet limited work has been carried out in the material modelling of such cases. In order to account for the effects of the accumulated defects, a micromechanical analysis based on the representative volume element has been considered, and phase-field modelling has been adopted to model the effects of inter-fiber cracking. The 3D models of representative volume elements were developed in the Abaqus environment based on the fiber dimensions and content acquired using machine learning algorithms, while fulfilling both geometric and material periodicity. Furthermore, the periodic boundary conditions were assumed for each of the representative volume elements in transversal and in-plane shear test cases,. The analysis was conducted by adopting an open-source UMAT subroutine, where the phase-field balance equation was related to the readily available heat transfer equation from Abaqus, avoiding the necessity for a dedicated user-defined element thus enabling the adoption of the standard elements and features available in the Abaqus CAE environment. The model was tested on three representative volume element sizes and the interface properties were calibrated according to the experimentally acquired results for continuous carbon-fiber-reinforced composites subjected to transverse tensile and shear loads. This investigation confirmed the consistency between the experimental results and the numerical solutions acquired using a phase-field fracture approach for the transverse tensile and shear behavior of additively manufactured continuous-fiber-reinforced composites, while showing dependence on the representative volume element type for distinctive load cases.
      Citation: Journal of Composites Science
      PubDate: 2023-01-12
      DOI: 10.3390/jcs7010038
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 39: Nanocomposites of Terbium Sulfide
           Nanoparticles with a Chitosan Capping Agent for Antibacterial Applications

    • Authors: Eny Kusrini, Alya Irma Safira, Anwar Usman, Eko Adi Prasetyanto, Khoirina Dwi Nugrahaningtyas, Sri Juari Santosa, Lee D. Wilson
      First page: 39
      Abstract: This study aims to investigate the effect of alkaline pH on the bottom-up synthesis of nanocomposites (NCs) containing terbium sulfide nanoparticles (Tb2S3 NPs), where chitosan (CS) was employed as a capping agent, along with evaluation of the antibacterial activity of these NCs. The NCs were characterized using spectroscopy (FESEM-EDX, Raman, FTIR, XRD, XPS, and DLS), zeta-potential, and TGA. The results of FE-SEM, XPS, Raman, and FTIR characterization support the formation of CS-Tb2S3 NPs. A pH variation from 9 to 11 during composite formation was shown to affect the size and composition of NCs. The antibacterial activity of CS-Tb2S3 NCs was studied by coating onto commercial contact lenses, where the best loading efficiency of NCs was 48%. The NCs prepared at pH 10 (without contact lenses) had greater antibacterial activity against Staphylococcus aureus, with a zone of inhibition diameter of 7.15 mm. The coating of NCs onto commercial contact lenses was less effective for inhibition of Staphylococcus aureus, in contrast with the greater activity observed for tetracycline. CS-Tb2S3 NCs offer promising antimicrobial properties that can be further optimized by control of the surface loading and accessibility of Tb2S3 NPs through further study of the role of the chitosan capping agent, since steric effects due to CS are likely to attenuate antimicrobial activity via reduced electron transfer in such nanocomposite systems.
      Citation: Journal of Composites Science
      PubDate: 2023-01-12
      DOI: 10.3390/jcs7010039
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 40: Microleakage Study of a Bulk Fill over
           an Uncured Adhesive System

    • Authors: Mariana Vaz Pinto, Salomé Pires, Carlos Miguel Marto, Inês Amaro, Ana Coelho, José Sousa, Manuel Marques Ferreira, Maria Filomena Botelho, Eunice Carrilho, Ana Margarida Abrantes, Anabela Baptista Paula
      First page: 40
      Abstract: This study aimed to evaluate and compare the microleakage of composite resin restorations under a total-etch adhesive system applied with two different techniques, with and without cure. Cavities were made on the buccal surface of twenty-six intact teeth and subsequently restored with bulk-fill flow composite resin (SDR®® flow+) and conventional resin (Spectra™ ST HV). Two experimental groups were created, one where the total-etch adhesive (Prime & Bond Active®) was cured and another where the adhesive was not cured before placing the flowable resin. Two control groups were also created, negative and positive. After the restorations were finished the, teeth were submerged in a solution of sodium pertechnetate (99mTcNaO4) for 3 h to evaluate the microleakage. The results showed more infiltration of radioisotopes characterized by the highest total count values of microleakage in group 1 (cured adhesive) and in the positive control. Group 2 (noncured adhesive) and the negative control showed lower values. We therefore considered that these groups were similar since their p-value was less than 0.05, with no statistically significant difference. Group 4 showed a statistically significant increase in relation to group 3 (p = 0.027). We concluded that the method of bulk-fill composite resins with noncured adhesive agents can have a positive effect on the longevity of bond strengths, with reduced microleakage.
      Citation: Journal of Composites Science
      PubDate: 2023-01-13
      DOI: 10.3390/jcs7010040
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 41: Cationic Polymerized Epoxy and
           Radiation Cured Acrylate Blend Nanocomposites Based on WS2
           Nanoparticles—Part A: Curing Processes and Kinetics

    • Authors: Gilad Gershoni, Hanna Dodiuk, Reshef Tenne, Samuel Kenig
      First page: 41
      Abstract: Cationic photo-initiated and polymerized epoxies are characterized by good adhesion, high modulus, zero volatiles, low shrinkage and living polymerization characteristics. Radiation—cured acrylate resins are characterized by rapid initial curing with increased initial strength. The combination of radiation-cured acrylates and epoxies may present advantageous attributes. Thus, the system investigated is a hybrid epoxy/methyl acrylate and three different initiators for cationic polymerization of epoxies, the radical reaction of acrylates and the thermal initiator. When incorporating additives like opaque WS2 nanoparticles (NPs), absorption of the photo radiation takes place, which may lead to low photo activity. Curing kinetics measurements revealed that the absorbing/masking effect of WS2 was insignificant, and surprisingly, the level of curing was enhanced when the WS2 NPs were incorporated. FTIR results demonstrated that covalent bonds were formed between the inorganic fullerenes (IF-WS2) and the crosslinked matrix. Viscosity measurements showed a surprising reduction of five to ten times in the low-shear viscosity upon NPs incorporation compared to neat resins. It was concluded that the decrease of viscosity by the inorganic NPs, in addition to the enhanced level of conversion, has profound advantages for structural adhesives and 3D printing resins. To the best of our knowledge, this investigation is the first to report on a radiation-induced curing system containing opaque WS2 NPs that leads to an enhanced degree of curing and reduced shear viscosity.
      Citation: Journal of Composites Science
      PubDate: 2023-01-16
      DOI: 10.3390/jcs7010041
      Issue No: Vol. 7, No. 1 (2023)
  • J. Compos. Sci., Vol. 7, Pages 42: Cationically Polymerized Epoxy and
           Radiation-Cured Acrylate Blend Nanocomposites Based on WS2 Nanoparticles
           Part B: Mechanical and Physical Properties

    • Authors: Gilad Gershoni, Hanna Dodiuk, Reshef Tenne, Samuel Kenig
      First page: 42
      Abstract: The radiation curing paradigm of opaque WS2 nanoparticle (NP)-based epoxy/acrylate nanocomposites was studied and found to exhibit both a reduction in viscosity and an enhanced degree of curing when incorporating WS2 NPs. The objective of this study was to investigate the mechanical, thermal, and physical properties of a radiation-induced and cured epoxy/acrylate blend containing 0.3 to 1.0 wt.% WS2 NPs. Experimental results indicate that the tensile toughness increased by 22% upon optimizing the NP content compared to that of WS2-free formulations. Tensile fractured surfaces with different WS2 NP contents were analyzed with a scanning electron microscope and an atomic force microscope and showed distinctive morphology depending on the WS2 NP content, supporting the results of the tensile test. The energy required to break shear adhesion specimens demonstrated an increase of up to 60% compared to that of the neat resin. The glass transition temperature determined by dynamic mechanical analysis presented similar or higher values upon WS2 NP incorporation. Furthermore, up to 80% improvement in impact strength was demonstrated when WS2 NPs were dispersed in the epoxy/acrylate blend. It was concluded that the surface chemistry and dispersion level of the WS2 NPs are the major variables affecting the macro properties of cationically radiation-cured resins and their adhesion properties. This study is the first to demonstrate the possibility for radiation-induced curing of opaque NPs based on WS2 that serve as both a reinforcement nanoparticle at low concentrations and an enhancement of the degree of curing.
      Citation: Journal of Composites Science
      PubDate: 2023-01-16
      DOI: 10.3390/jcs7010042
      Issue No: Vol. 7, No. 1 (2023)
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