Subjects -> CHEMISTRY (Total: 1001 journals)
    - ANALYTICAL CHEMISTRY (59 journals)
    - CHEMISTRY (726 journals)
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    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (45 journals)
    - ORGANIC CHEMISTRY (49 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (726 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
Accounts of Materials Research     Hybrid Journal  
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 36)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 15)
ACS Catalysis     Hybrid Journal   (Followers: 78)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 25)
ACS Combinatorial Science     Hybrid Journal   (Followers: 25)
ACS Macro Letters     Hybrid Journal   (Followers: 34)
ACS Materials Letters     Open Access   (Followers: 4)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 49)
ACS Nano     Hybrid Journal   (Followers: 451)
ACS Photonics     Hybrid Journal   (Followers: 19)
ACS Symposium Series     Full-text available via subscription   (Followers: 3)
ACS Synthetic Biology     Hybrid Journal   (Followers: 40)
Acta Chemica Iasi     Open Access   (Followers: 8)
Acta Chemica Malaysia     Open Access  
Acta Chimica Slovaca     Open Access   (Followers: 4)
Acta Chimica Slovenica     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access   (Followers: 1)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 10)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 10)
Adsorption Science & Technology     Open Access   (Followers: 9)
Advanced Electronic Materials     Hybrid Journal   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 81)
Advanced Journal of Chemistry, Section A     Open Access   (Followers: 15)
Advanced Journal of Chemistry, Section B     Open Access   (Followers: 14)
Advanced Science Focus     Free   (Followers: 7)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 108)
Advances in Chemical Science     Open Access   (Followers: 50)
Advances in Chemistry     Open Access   (Followers: 39)
Advances in Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 21)
Advances in Drug Research     Full-text available via subscription   (Followers: 27)
Advances in Environmental Chemistry     Open Access   (Followers: 11)
Advances in Enzyme Research     Open Access   (Followers: 13)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 20)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 35)
Advances in Nanoparticles     Open Access   (Followers: 20)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 20)
Advances in Polymer Science     Hybrid Journal   (Followers: 54)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 22)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7)
Advances in Science and Technology     Full-text available via subscription   (Followers: 17)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 6)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Aggregate     Open Access   (Followers: 3)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 3)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 5)
Alchemy : Jurnal Penelitian Kimia     Open Access   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 71)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 24)
American Journal of Chemistry     Open Access   (Followers: 41)
American Journal of Plant Physiology     Open Access   (Followers: 13)
Analyst     Full-text available via subscription   (Followers: 40)
Analytical Science Advances     Open Access   (Followers: 2)
Angewandte Chemie     Hybrid Journal   (Followers: 236)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 353)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 8)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 4)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 6)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 9)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 13)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 16)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 12)
Applied Spectroscopy     Full-text available via subscription   (Followers: 27)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 2)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemical Sciences     Open Access   (Followers: 1)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 3)
Atomization and Sprays     Full-text available via subscription   (Followers: 8)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 7)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 484)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 3)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 4)
Biomacromolecules     Hybrid Journal   (Followers: 27)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 4)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 215)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 88)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 4)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 26)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 5)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 13)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Polymer Technologies and Applications     Open Access   (Followers: 3)
Carbohydrate Polymers     Hybrid Journal   (Followers: 13)
Carbohydrate Research     Hybrid Journal   (Followers: 26)
Carbon     Hybrid Journal   (Followers: 76)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 13)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 4)
Catalysts     Open Access   (Followers: 14)
Cell Reports Physical Science     Open Access  
Cellulose     Hybrid Journal   (Followers: 17)
Cereal Chemistry     Full-text available via subscription   (Followers: 6)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 11)
Chemical and Engineering News     Free   (Followers: 24)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 88)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 28)
Chemical Physics Letters : X     Open Access   (Followers: 4)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 4)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 25)
Chemical Reviews     Hybrid Journal   (Followers: 267)
Chemical Science     Open Access   (Followers: 44)
Chemical Science International Journal     Open Access   (Followers: 1)
Chemical Technology     Open Access   (Followers: 71)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 23)
ChemInform     Hybrid Journal   (Followers: 9)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 31)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 225)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 20)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 24)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 8)
Chemistry Education Review     Open Access   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry Letters     Full-text available via subscription   (Followers: 49)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 339)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 20)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
Chemistry–Methods     Open Access   (Followers: 2)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 14)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 14)
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access   (Followers: 1)
ChemSystemsChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Open Access   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 13)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Ciencia     Open Access   (Followers: 1)
Clay Minerals     Hybrid Journal   (Followers: 9)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 12)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 8)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 24)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)

        1 2 3 4 | Last

Similar Journals
Journal Cover
C - Journal of Carbon Research
Number of Followers: 5  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2311-5629
Published by MDPI Homepage  [238 journals]
  • C, Vol. 7, Pages 67: Atomic Layer Deposition of Nanolayered Carbon Films

    • Authors: Zhigang Xiao, Kim Kisslinger, Rebhadevi Monikandan
      First page: 67
      Abstract: In this paper, carbon thin films were grown using the plasma-enhanced atomic layer deposition (PE-ALD). Methane (CH4) was used as the carbon precursor to grow the carbon thin film. The grown film was analyzed by the high-resolution transmission electron micrograph (TEM), X-ray photoelectron spectroscopy (XPS) analysis, and Raman spectrum analysis. The analyses show that the PE-ALD-grown carbon film has an amorphous structure. It was found that the existence of defective sites (nanoscale holes or cracks) on the substrate of copper foil could facilitate the formation of nanolayered carbon films. The mechanism for the formation of nanolayered carbon film in the nanoscale holes was discussed. This finding could be used for the controlled growth of nanolayered carbon films or other two-dimensional nanomaterials while combining with modern nanopatterning techniques.
      Citation: C
      PubDate: 2021-09-27
      DOI: 10.3390/c7040067
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 68: CH Activation by a Heavy Metal Cation: Production of
           H2 from the Reaction of Acetylene with C4H4-Os(+) in Gas phase

    • Authors: Zikri Altun, Erdi Ata Bleda, Carl Trindle
      First page: 68
      Abstract: While first-row transition metal cations, notably Fe(+), catalyze the gas-phase conversion of acetylene to benzene, a distinct path is chosen in systems with Os, Ir, and Rh cations. Rather than losing the metal cation M(+) from the benzene–M(+) complex, as is observed for the Fe(+) system, the heavy metal ions activate CH bonds. The landmark system C4H4-Os(+) reacts with acetylene to produce C6H4-Os(+) and dihydrogen. Following our work on isomers of the form C2nH2n-Fe(+), we show by DFT modeling that the CH bonds of the metalla-7-cycle structure, C6H6-Os(+), are activated and define the gas-phase reaction path by which H2 is produced. The landmark structures on the network of reaction paths can be used as a basis for the discussion of reactions in which a single Os atom on an inert surface can assist reactions of hydrocarbons.
      Citation: C
      PubDate: 2021-09-30
      DOI: 10.3390/c7040068
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 69: Nanoporous Carbon Magnetic Hybrid Derived From
           Waterlock Polymers and Its Application for Hexavalent Chromium Removal
           from Aqueous Solution

    • Authors: Georgios Asimakopoulos, Angeliki Karakassides, Maria Baikousi, Christina Gioti, Dimitrios Moschovas, Apostolos Avgeropoulos, Athanasios B. Bourlinos, Alexios P. Douvalis, Constantinos E. Salmas, Michael A. Karakassides
      First page: 69
      Abstract: Sodium polyacrylate is the superabsorbent waterlock polymer used in disposable diapers, which are the third largest single consumer item in landfills. As diapers are difficult to recycle, their use produces an incredible amount of environmental waste. In the present article, we present a reliable and facile approach to transform sodium polyacrylate, the main constitute in the used diapers, in a carbon-based magnetic sorbent material, capable for use in environmental applications. A nanoporous carbon magnetic hybrid material was prepared by reacting NaPA with iron acetate species under chemical activation conditions. Analysis of the characterization results revealed, the creation of a nanoporous structure, with high specific surface area value (SgBET = 611 m2/g), along with the formation of nanosized zero valent iron nanoparticles and iron carbide (Fe3C), inside the carbon pore system. 57Fe Mössbauer spectroscopy verified also the existence of these two main iron-bearing phases, as well as additional minor magnetic phases, such as Fe3O4 and γ-Fe2O3. Vibrating sample magnetometry (VSM) measurements of the obtained hybrid confirmed its ferromagnetic/ferrimagnetic behavior. The hybrid material demonstrated a rapid sorption of Cr(VI) ions (adsorption capacity: 90 mg/g, 24 h pH = 3). The results showed highly pH-dependent sorption efficiency of the hybrids, whereas a pseudo-second-order kinetic model described their kinetics.
      Citation: C
      PubDate: 2021-09-30
      DOI: 10.3390/c7040069
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 70: Fabrication and Supercapacitor Applications of
           Multiwall Carbon Nanotube Thin Films

    • Authors: Kyle Jiang, Rosario A. Gerhardt
      First page: 70
      Abstract: Multiwalled carbon nanotubes (MWCNTs) are a one-dimensional nanomaterial with several desirable material properties, including high mechanical tensile modulus and strength, high electrical conductivity, and good thermal conductivity. A wide variety of techniques have been optimized to synthesize MWCNTs and to fabricate thin films of MWCNTs. These synthesis and fabrication methods vary based on precursor materials, process parameters, and physical and chemical principals, and have a strong influence on the properties of the nanotubes and films. Thus, the fabrication methods determine the performance of devices that can exploit the advantageous material properties of MWCNTs. Techniques for the fabrication of carbon nanotubes and carbon nanotube thin films are reviewed, followed by a discussion of the use of MWCNTs as an electrode material for electrochemical double-layer supercapacitors (EDLCs). EDLCs feature high power density, excellent reversibility and lifetime, and improved energy density over electrolytic capacitors. Beyond surveying fabrication techniques previously explored for MWCNT electrodes, an alternative approach based on inkjet printing capable of depositing a small amount of active material is discussed. Such an approach allows for a high degree of control over electrode properties and can potentially reduce cost and active material waste, which are essential components to the gradual conversion to green energy.
      Citation: C
      PubDate: 2021-09-30
      DOI: 10.3390/c7040070
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 71: Applicability of Atmospheric Pressure Plasma Jet
           (APPJ) Discharge for the Reduction in Graphene Oxide Films and Synthesis
           of Carbon Nanomaterials

    • Authors: Sri Hari Bharath Vinoth Kumar, Josefa Ibaceta-Jaña, Natalia Maticuic, Krystian Kowiorski, Matthias Zelt, Ulrich Gernert, Ludwika Lipińska, Bernd Szyszka, Rutger Schlatmann, Uwe Hartmann, Ruslan Muydinov
      First page: 71
      Abstract: Atmospheric pressure plasma jets (APPJ) are widely used in industry for surface cleaning and chemical modification. In the recent past, they have gained more scientific attention especially in the processing of carbon nanomaterials. In this work, a novel power generation technique was applied to realize the stable discharge in N2 (10 vol.% H2) forming gas in ambient conditions. This APPJ was used to reduce solution-processed graphene oxide (GO) thin films and the result was compared with an established and optimized reduction process in a low–pressure capacitively coupled (CCP) radiofrequency (RF) hydrogen (H2) plasma. The reduced GO (rGO) films were investigated by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Effective deoxygenation of GO was observed after a quick 2 s treatment by AAPJ. Further deoxygenation at longer exposure times was found to proceed with the expense of GO–structure integrity. By adding acetylene gas into the same APPJ, carbon nanomaterials on various substrates were synthesized. The carbon materials were characterized by Raman spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analyses. Fullerene-like particles and graphitic carbon with short carbon nanotubes were detected on Si and Ag surfaces, respectively. We demonstrate that the APPJ tool has obvious potential for the versatile processing of carbon nanomaterials.
      Citation: C
      PubDate: 2021-10-14
      DOI: 10.3390/c7040071
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 72: Effects of Reducing Agent on the Activity of
           PtRu/Carbon Black Anode Catalyst of Direct Methanol Fuel Cell

    • Authors: Yu-Wen Chen, Han-Gen Chen
      First page: 72
      Abstract: A series of PtRu/carbon black catalysts were prepared by means of deposition-precipitation and reduced by various reducing agents. NaBH4, HCHO and NaH2PO2, respectively, were used as the reduction agents. Some of the samples were reduced by various amounts of NaH2PO2 to investigate the effects of P/Pt ratios on the characteristics and activity of the catalyst. These catalysts were characterized by X-ray diffraction and transmission electron microscopy. The components of these catalysts were detected by X-ray fluorescence, X-ray photoelectron microscopy, and extended X-ray absorption of fine structures (EXAFS). The methanol oxidation ability of the catalysts was tested by cyclic voltammetry measurement. The results show that NaH2PO2 could effectively reduce the particle size of PtRu metal. It can suppress the growth of metal particles. In addition, the P/Pt ratio is crucial. The catalyst reduced by NaH2PO2 with a P/Pt ratio of 1.2 had the highest activity among all catalysts. It had the higher Pt and Ru metal contents and smaller metal particle size than the other catalysts. Its activity was 253.12 A/g, which is higher that than the commercial catalyst (Johnson Matthey H10100, 251.32 A/g).
      Citation: C
      PubDate: 2021-10-19
      DOI: 10.3390/c7040072
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 73: Carbon Nanoarchitectonics for Energy and Related
           Applications

    • Authors: Rekha Goswami Shrestha, Lok Kumar Shrestha, Katsuhiko Ariga
      First page: 73
      Abstract: Nanoarchitectonics has been recently proposed as a post-nanotechnology concept. It is the methodology to produce functional materials from nanoscale units. Carbon-based materials are actively used in nanoarchitectonics approaches. This review explains several recent examples of energy and related applications of carbon materials from the viewpoint of the nanoarchitectonics concept. Explanations and discussions are described according to the classification of carbon sources for nanostructured materials: (i) carbon nanoarchitectonics from molecules and supramolecular assemblies; (ii) carbon nanoarchitectonics from fullerenes; (iii) carbon nanoarchitectonics from biomass; and (iv) carbon nanoarchitectonics with composites and hybrids. Functional carbon materials can be nanoarchitected through various processes, including well-skilled organic synthesis with designed molecular sources; self-assembly of fullerenes under various conditions; practical, low-cost synthesis from biomass; and hybrid/composite formation with various carbon sources. These examples strikingly demonstrate the enormous potential of nanoarchitectonics approaches to produce functional carbon materials from various components such as small molecules, fullerene, other nanocarbons, and naturally abundant biomasses. While this review article only shows limited application aspects in energy-related usages such as supercapacitors, applications for more advanced cells and batteries, environmental monitoring and remediation, bio-medical usages, and advanced devices are also expected.
      Citation: C
      PubDate: 2021-10-19
      DOI: 10.3390/c7040073
      Issue No: Vol. 7, No. 4 (2021)
       
  • C, Vol. 7, Pages 50: Carbons Formed in Methane Thermal and Thermocatalytic
           Decomposition Processes: Properties and Applications

    • Authors: Emmi Välimäki, Lasse Yli-Varo, Henrik Romar, Ulla Lassi
      First page: 50
      Abstract: The hydrogen economy will play a key role in future energy systems. Several thermal and catalytic methods for hydrogen production have been presented. In this review, methane thermocatalytic and thermal decomposition into hydrogen gas and solid carbon are considered. These processes, known as the thermal decomposition of methane (TDM) and thermocatalytic decomposition (TCD) of methane, respectively, appear to have the greatest potential for hydrogen production. In particular, the focus is on the different types and properties of carbons formed during the decomposition processes. The applications for carbons are also investigated.
      Citation: C
      PubDate: 2021-06-25
      DOI: 10.3390/c7030050
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 51: Comments on the XPS Analysis of Carbon Materials

    • Authors: David J. Morgan
      First page: 51
      Abstract: The surface chemistry of carbon materials is predominantly explored using x-ray photoelectron spectroscopy (XPS). However, many published papers have critical failures in the published analysis, stemming from an ill-informed approach to analyzing the spectroscopic data. Herein, a discussion on lineshapes and changes in the spectral envelope of predominantly graphitic materials are explored, together with the use of the D-parameter, to ascertain graphitic content, using this information to highlight a simple and logical approach to strengthen confidence in the functionalization derived from the carbon core-level spectra.
      Citation: C
      PubDate: 2021-07-06
      DOI: 10.3390/c7030051
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 52: Fused Filament Fabrication Three-Dimensional Printing
           Multi-Functional of Polylactic Acid/Carbon Black Nanocomposites

    • Authors: Nectarios Vidakis, Markos Petousis, Emmanuel Velidakis, Nikolaos Mountakis, Peder Erik Fischer-Griffiths, Sotirios Grammatikos, Lazaros Tzounis
      First page: 52
      Abstract: Conductive Polymer Composites (CPCs) have recently gained an extensive scientific interest as feedstock materials in Fused Filament Fabrication (FFF) Three-dimensional (3D) printing. Polylactic Acid (PLA), widely used in FFF 3D printing, as well as its Carbon Black (CB) nanocomposites at different weight percentage (wt.%) filler loadings (0.5, 1.0, 2.5 and 5.0 wt.%), were prepared via a melt mixing filament extrusion process in this study and utilized to manufacture FFF 3D printed specimens. The nanocomposites were examined for their electrical conductivity. The highest loaded 3D printed CPC (5.0 wt.%) was tested as an electrothermal Joule heating device. Static tensile, flexural, Charpy’s impact and Vickers microhardness mechanical properties were investigated for the neat and PLA/CB 3D printed nanocomposites. Dynamic Mechanical Analysis (DMA) revealed a stiffening mechanism for the PLA/CB nanocomposites. Scanning Electron Microscopy (SEM) elucidated the samples’ internal and external microstructural characteristics. The PLA/CB 5.0 wt.% nanocomposite demonstrated also antibacterial properties, when examined with a screening process, against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). It can be envisaged that the 3D printed PLA/CB CPCs exhibited a multi-functional performance, and could open new avenues towards low-cost personalized biomedical objects with complex geometry, amongst others, i.e., surgery tools, splints, wearables, etc.
      Citation: C
      PubDate: 2021-07-17
      DOI: 10.3390/c7030052
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 53: Reduction of Device Operating Temperatures with
           Graphene-Filled Thermal Interface Materials

    • Authors: Jacob S. Lewis
      First page: 53
      Abstract: The majority of research into few layer graphene (FLG) thermal interface materials (TIM) concerns the direct quantification of innate composite properties with much less direct analysis of these materials in realistic applications. In this study, equilibrium temperatures of engineered device substitutes fixed to passive heat sink solutions with varying FLG concentration TIMs are experimentally measured at varying heat dissipation rates. A custom, precisely-controlled heat source’s temperature is continually measured to determine equilibrium temperature at a particular heat dissipation. It is found that altering the used FLG TIM concentrations from 0 vol.% to as little as 7.3 vol.% resulted in a decrease of combined TIM and passively-cooled heat sink thermal resistance from 4.23∘C/W to 2.93∘C/W, amounting to a reduction in operating temperature of ≈108∘C down to ≈85∘C at a heat dissipation rate of 20 W. The results confirm FLG TIMs’ promising use in the application of device heat dissipation in a novel, controllable experimental technique.
      Citation: C
      PubDate: 2021-07-21
      DOI: 10.3390/c7030053
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 54: Facile Synthesis and Characterization of a
           Bromine-Substituted (Chloromethyl)Pyridine Precursor Towards the
           

    • Authors: Troy T. Handlovic, Tyler Moreira, Anoshia Khan, Haroon Saeed, Yousuf Khan, Mohammed R. Elshaer, Justin A. Bogart
      First page: 54
      Abstract: Multidentate ligands involving tethered pyridyl groups coordinated to transition metal ions have been frequently used to mimic the 3-histidine (3H), 2-histidine-1-carboxylate (2H1C) brace motifs or other combinations of histidine and carboxylate endogenous ligating residues found in bioinorganic metalloenzymes. It is of interest to immobilize these ligand chelates onto heterogeneous supports. This, however, requires the use of bromine-substituted (chloromethyl)pyridines, whose current synthetic routes involve the use of extremely pyrophoric chemicals, such as n-butyllithium that require cryogenic reaction conditions, and toxic chemicals, such as thionyl chloride, that are challenging to handle and require extensive hazard controls. Herein, we report alternative methodologies towards the syntheses of 2-bromo-6-hydroxymethylpyridine and 2-bromo-6-chloromethylpyridine from inexpensive commercially available 2,6-dibromopyridine using isopropylmagnesium chloride lithium chloride complex (Turbo Grignard) and cyanuric chloride which are easier to handle and require milder reaction conditions than the conventional reagents. Gas chromatography-mass spectrometry (GC-MS) methods were developed and simple 1H- and 13C- nuclear magnetic resonance (NMR) and Fourier-transform infrared (FT-IR) spectroscopies were also used to monitor the conversion of both reaction steps and showed that products could be obtained and isolated through simple workups without the presence of unreacted starting material or undesired overchlorinated 2-chloro-6-chloromethylpyridine side product.
      Citation: C
      PubDate: 2021-07-23
      DOI: 10.3390/c7030054
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 55: Biomass-Derived Carbons as Versatile Materials for
           Energy-Related Applications: Capacitive Properties vs. Oxygen Reduction
           Reaction Catalysis

    • Authors: Stefan Breitenbach, Nemanja Gavrilov, Igor Pašti, Christoph Unterweger, Jiri Duchoslav, David Stifter, Achim Walter Hassel, Christian Fürst
      First page: 55
      Abstract: Biomass-derived carbons are very attractive materials due to the possibility of tuning their properties for different energy-related applications. Various pore sizes, conductivities and the inherent presence of heteroatoms make them attractive for different electrochemical reactions, including the implementation of electrochemical capacitors or fuel cell electrodes. This contribution demonstrates how different biomass-derived carbons prepared from the same precursor of viscose fibers can reach appreciable capacitances (up to 200 F g−1) or a high selectivity for the oxygen reduction reaction (ORR). We find that a highly specific surface area and a large mesopore volume dominate the capacitive response in both aqueous and non-aqueous electrolytic solutions. While the oxygen reduction reaction activity is not dominated by the same factors at low ORR overpotentials, these take the dominant role over surface chemistry at high ORR overpotentials. Due to the high selectivity of the O2 reduction to peroxide and the appreciable specific capacitances, it is suggested that activated carbon fibers derived from viscose fibers are an attractive and versatile material for electrochemical energy conversion applications.
      Citation: C
      PubDate: 2021-07-24
      DOI: 10.3390/c7030055
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 56: Preparation and Carbonization of Glucose and
           Pyromellitic Dianhydride Crosslinked Polymers

    • Authors: Fabrizio Caldera, Antonella Moramarco, Federico Cesano, Anastasia Anceschi, Alessandro Damin, Marco Zanetti
      First page: 56
      Abstract: In this work, four types of nanosponges were prepared from pyromellitic dianhydride (PMDA) and D-glucose (GLU) with different molar ratios (1.5:1, 2:1, 2.5:1 and 3:1). The obtained PMDA/GLU nanosponges were then pyrolyzed at 800 °C for 30 min under N2 gas flow. The prepared polymeric nanosponges were investigated by FTIR spectroscopy, elemental and thermogravimetric analyses to unravel the role played by the different molar ratio of the precursors in the formation of the polymer. The pyrolyzed nanosponges were investigated by means of porosity measurements, X-ray diffraction analysis, Raman spectroscopy and high-resolution transmission electron microscopy. Notably, no significant correlation of the amounts of used precursors with the porous texture and structure was evidenced. The results corroborate that PMDA and GLU can be easily combined to prepare nanosponges and that the carbon materials produced by their pyrolysis can be associated with glassy carbons with a microporous texture and relatively high surface area. Such hard carbons can be easily obtained and shrewdly used to segregate relatively small molecules and organic contaminants; in this study methylene blue adsorption was investigated.
      Citation: C
      PubDate: 2021-07-26
      DOI: 10.3390/c7030056
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 57: Ab Initio Study of Porous Graphene–CNT Silicon
           Composite for Li-Ion and Na-Ion Batteries

    • Authors: Dmitry A. Kolosov, Olga E. Glukhova
      First page: 57
      Abstract: In this work, we investigated composite materials based on graphene and carbon nanotubes with a silicon cluster from the standpoint of using them as Li-ion battery (LIB) and Na-ion battery (NIB) anodes. For our study, we used the density functional theory method, taking into account the van der Waals interaction. The cavities of the composite were filled with lithium and sodium, and the energy characteristics of the structure were calculated through SIESTA molecular dynamics. The calculations showed the negative energy of adsorption for lithium and sodium and the negative value of the heat of formation of the composites. The introduction of a silicon cluster led to an increase in the specific capacity by 22.2% for the sodium and 37% for the lithium in comparison with the pure composite. The calculation of the transmission function showed a decrease in the resistance of the composite when a silicon cluster was added to the composite. We predict that the application of the considered composite will increase the efficiency of existing lithium-ion and sodium-ion batteries.
      Citation: C
      PubDate: 2021-07-29
      DOI: 10.3390/c7030057
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 58: Review of Cryogenic Carbon Capture Innovations and
           Their Potential Applications

    • Authors: Carolina Font-Palma, David Cann, Chinonyelum Udemu
      First page: 58
      Abstract: Our ever-increasing interest in economic growth is leading the way to the decline of natural resources, the detriment of air quality, and is fostering climate change. One potential solution to reduce carbon dioxide emissions from industrial emitters is the exploitation of carbon capture and storage (CCS). Among the various CO2 separation technologies, cryogenic carbon capture (CCC) could emerge by offering high CO2 recovery rates and purity levels. This review covers the different CCC methods that are being developed, their benefits, and the current challenges deterring their commercialisation. It also offers an appraisal for selected feasible small- and large-scale CCC applications, including blue hydrogen production and direct air capture. This work considers their technological readiness for CCC deployment and acknowledges competing technologies and ends by providing some insights into future directions related to the R&D for CCC systems.
      Citation: C
      PubDate: 2021-07-29
      DOI: 10.3390/c7030058
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 59: The Growth Behavior of Amorphous Hydrogenated Carbon
           a-C:H Layers on Industrial Polycarbonates—A Weak Interlayer and a
           Distinct Dehydrogenation Zone

    • Authors: Torben Schlebrowski, Melanie Fritz, Lucas Beucher, Yongxin Wang, Stefan Wehner, Christian B. Fischer
      First page: 59
      Abstract: Polycarbonate (PC) is a material that is used in many areas: automotive, aerospace engineering and data storage industries. Its hardness is of particular importance, but some applications are affected by its low wettability or scratch susceptibility. This can be changed either by blending with other polymers, or by surface modifications, such as the application of an amorphous hydrogenated carbon layer (a-C:H). In this study, individual a-C:H layers of different thicknesses (10–2000 nm) were deposited on PC by RF PECVD. Both the layer morphology with AFM and SEM and the bonding states of the carbon on the surface with synchrotron-assisted XPS and NEXAFS were studied. The aim was to investigate the coatability of PC and the stability of the a-C:H. Special attention was paid to the interlayer region from 0 to 100 nm, since this is responsible for the layer to base material bonding, and to the zone of dehydrogenation (from about 1000 nm), since this changes the surface composition considerably. For PC, the interlayer was relatively small with a thickness of only 20 nm. Additionally, a correlation was found between the evolving grain structure and the development of the C‒H peak according to NEXAFS C K-edge measurements.
      Citation: C
      PubDate: 2021-07-29
      DOI: 10.3390/c7030059
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 60: Monitoring of Curing and Cyclic Thermoresistive
           Response Using Monofilament Carbon Nanotube Yarn Silicone Composites

    • Authors: Tannaz Tayyarian, Omar Rodríguez-Uicab, Jandro L. Abot
      First page: 60
      Abstract: The curing process and thermoresistive response of a single carbon nanotube yarn (CNTY) embedded in a room temperature vulcanizing (RTV) silicone forming a CNTY monofilament composite were investigated toward potential applications in integrated curing monitoring and temperature sensing. Two RTV silicones of different crosslinking mechanisms, SR1 and SR2 (tin- and platinum-cured, respectively), were used to investigate their curing kinetics using the electrical response of the CNTY. It is shown that the relative electrical resistance change of CNTY/SR1 and CNTY/SR2 monofilament composites increased by 3.8% and 3.3%, respectively, after completion of the curing process. The thermoresistive characterization of the CNTY monofilament composites was conducted during heating–cooling ramps ranging from room temperature (RT~25 °C) to 100 °C. The thermoresistive response was nearly linear with a negative temperature coefficient of resistance (TCR) at heating and cooling sections for both CNTY/SR1 and CNTY/SR2 monofilament composites. The average TCR value was −8.36 × 10−4 °C−1 for CNTY/SR1 and −7.26 × 10−4 °C−1 for CNTY/SR2. Both monofilament composites showed a negligible negative residual relative electrical resistance change with average values of ~−0.11% for CNTY/SR1 and ~−0.16% for CNTY/SR2 after each cycle. The hysteresis amounted to ~21.85% in CNTY/SR1 and ~29.80% in CNTY/SR2 after each cycle. In addition, the effect of heating rate on the thermoresistive sensitivity of CNTY monofilament composites was investigated and it was shown that it reduces as the heating rate increases.
      Citation: C
      PubDate: 2021-08-04
      DOI: 10.3390/c7030060
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 61: Applicability and Limitations of Simplified Elastic
           Shell Theories for Vibration Modelling of Double-Walled Carbon Nanotubes

    • Authors: Matteo Strozzi, Oleg V. Gendelman, Isaac E. Elishakoff, Francesco Pellicano
      First page: 61
      Abstract: The applicability and limitations of simplified models of thin elastic circular cylindrical shells for linear vibrations of double-walled carbon nanotubes (DWCNTs) are considered. The simplified models, which are based on the assumptions of membrane and moment approximate thin-shell theories, are compared with the extended Sanders–Koiter shell theory. Actual discrete DWCNTs are modelled by means of couples of concentric equivalent continuous thin, circular cylindrical shells. Van der Waals interaction forces between the layers are taken into account by adopting He’s model. Simply supported and free–free boundary conditions are applied. The Rayleigh–Ritz method is considered to obtain approximate natural frequencies and mode shapes. Different aspect and thickness ratios, and numbers of waves along longitudinal and circumferential directions, are analysed. In the cases of axisymmetric and beam-like modes, it is proven that membrane shell theory, differently from moment shell theory, provides results with excellent agreement with the extended Sanders–Koiter shell theory. On the other hand, in the case of shell-like modes, it is found that both membrane and moment shell theories provide results reporting acceptable agreement with the extended Sanders–Koiter shell theory only for very limited ranges of geometries and wavenumbers. Conversely, for shell-like modes it is found that a newly developed, simplified shell model, based on the combination of membrane and semi-moment theories, provides results in satisfactory agreement with the extended Sanders–Koiter shell theory in all ranges.
      Citation: C
      PubDate: 2021-08-09
      DOI: 10.3390/c7030061
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 62: Asymmetric Fiber Supercapacitors Based on a
           FeC2O4/FeOOH-CNT Hybrid Material

    • Authors: Paa Kwasi Adusei, Kevin Johnson, Sathya N. Kanakaraj, Guangqi Zhang, Yanbo Fang, Yu-Yun Hsieh, Mahnoosh Khosravifar, Seyram Gbordzoe, Matthew Nichols, Vesselin Shanov
      First page: 62
      Abstract: The development of new flexible and lightweight electronics has increased the demand for compatible energy storage devices to power them. Carbon nanotube (CNT) fibers have long been known for their ability to be assembled into yarns, offering their integration into electronic devices. They are hindered, however, by their low intrinsic energy storage properties. Herein, we report a novel composite yarn, synthesized through solvothermal processes, that attained energy densities in the range between 0.17 µWh/cm2 and 3.06 µWh/cm2, and power densities between 0.26 mW/cm2 and 0.97 mW/cm2, when assembled in a supercapacitor with a PVDF-EMIMBF4 electrolyte. The created unique composition of iron oxalate + iron hydroxide + CNT as an anode worked well in synergy with the much-studied PANI + CNT cathode, resulting in a highly stable yarn energy storage device that maintained 96.76% of its energy density after 4000 cycles. This device showed no observable change in performance under stress/bend tests which makes it a viable candidate for powering wearable electronics.
      Citation: C
      PubDate: 2021-08-14
      DOI: 10.3390/c7030062
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 63: 2013–2014 Survey of Chars Using Raman
           Spectroscopy

    • Authors: John McDonald-Wharry
      First page: 63
      Abstract: In late 2013, an open call for charcoal and biochar samples was distributed in an effort to compare a wide range of char samples by Raman spectroscopy. The samples contributed to this survey included: laboratory produced biochars, recent biochars produced in field conditions, and ancient char samples previously analysed by carbon dating. By using selected Raman measurements, the char samples could be ranked in terms of the degree of thermochemical alteration or extent of carbon nanostructural development. The Raman results for recently produced biomass chars were generally consistent with the conversion of amorphous carbon formed at lower temperatures into condensed, polyaromatic, and graphene-like carbon formed at higher temperatures. A number of parameters calculated from the Raman spectra could be used to estimate the effective heat treatment temperatures in the recently produced biochars. Other samples such as anthracite coal, tire pyrolysis carbon, and ancient chars departed from the trends observed in the recently produced biomass chars using this approach. In total, 45 samples were analysed by Raman spectroscopy for this survey. Ancient and buried char samples displayed higher intensities for features in the Raman spectra associated with amorphous carbon.
      Citation: C
      PubDate: 2021-08-19
      DOI: 10.3390/c7030063
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 64: Thermal and Principal Ablation Properties of
           Carbon-Fibre-Reinforced Polymers with Out-of-Plane Fibre Orientation

    • Authors: Sebastian Eibl, Thomas J. Schuster
      First page: 64
      Abstract: This work characterises thermal properties of a typical epoxy-based carbon-fibre-reinforced polymer used in aircraft construction, but with an out-of-plane fibre orientation, and assesses its potential as a structural ablative material. Samples of the commercially available Hexply® 8552/IM7 are prepared with out-of-plane angles up to 90°, with a focus on 0° to 15°, enhancing thermal conductivity through the thickness of the panel. Ablation processes are simulated by a hot-air blower at 580 °C, and examined in detail by ultrasonic testing and microfocused computed X-ray tomography afterwards. Matrix degradation is characterised by infrared spectroscopy and mass loss. To assess structural properties, tensile, compression, and bending tests are performed. The results show a loss in mechanical performance with an increasing fibre angle, which may be negligible for angles lower than ~5° in the initial state. Composite material with an out-of-plane fibre orientation is deeply penetrated concerning matrix degradation by thermal loading, but it is held together by the fibres fixed in the intact matrix underneath. This type of material shows a high potential for structural components in single-use, high-temperature, ablative applications with a focus on saving weight.
      Citation: C
      PubDate: 2021-08-21
      DOI: 10.3390/c7030064
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 65: Graphene-Enhanced Battery Components in Rechargeable
           Lithium-Ion and Lithium Metal Batteries

    • Authors: Hao-Hsun Chang, Tseng-Hsiang Ho, Yu-Sheng Su
      First page: 65
      Abstract: Stepping into the 21st century, “graphene fever” swept the world due to the discovery of graphene, made of single-layer carbon atoms with a hexagonal lattice. This wonder material displays impressive material properties, such as its electrical conductivity, thermal conductivity, and mechanical strength, and it also possesses unique optical and magnetic properties. Many researchers see graphene as a game changer for boosting the performance of various applications. Emerging consumer electronics and electric vehicle technologies require advanced battery systems to enhance their portability and driving range, respectively. Therefore, graphene seems to be a great candidate material for application in high-energy-density/high-power-density batteries. The “graphene battery”, combining two Nobel Prize-winning concepts, is also frequently mentioned in the news and articles all over the world. This review paper introduces how graphene can be adopted in Li-ion/Li metal battery components, the designs of graphene-enhanced battery materials, and the role of graphene in different battery applications.
      Citation: C
      PubDate: 2021-09-16
      DOI: 10.3390/c7030065
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 66: Conformational Analysis of [60]PCBM from DFT
           Simulations of Electronic Energies, Bond Strain and the 13C NMR Spectrum:
           Input Geometry Determination and Ester Bond Rotation Dynamics

    • Authors: Tong Liu, T. John S. Dennis
      First page: 66
      Abstract: With the aim of determining the best input geometry for DFT calculations of [60]PCBM, the geometry of 24 chemically possible [60]PCBM conformers were optimised and their electronic energies and average bond strains were determined. A DFT analysis of the relevant dihedral angles provided insights into the dynamical behaviour of the ester group through sterically restricted bond rotations. In addition, the 13C NMR spectra of the six better performing conformers were simulated and compared with an experiment. There is a close correlation between average bond strain, total electronic energy and mean absolute error of the simulated 13C NMR spectra of the ester carbons. The best overall candidate conformer for the input geometry had the C61-C4, C4-C3 and C3-C2 single bonds of the alkyl chain in syn, anti and anti arrangements, respectively, and had the C2-C1 and C1-O single bonds of the ester in syn and anti arrangements, respectively. This contrasts strikingly with most representations of PCBM in the literature, which depict all relevant bonds in anti arrangements.
      Citation: C
      PubDate: 2021-09-21
      DOI: 10.3390/c7030066
      Issue No: Vol. 7, No. 3 (2021)
       
  • C, Vol. 7, Pages 30: Ultra-Thin Carbon Films: The Rise of sp3-C-Based 2D
           Materials'

    • Authors: Fabrice Piazza, Marc Monthioux
      First page: 30
      Abstract: We warmly thank all the colleagues who have enthusiastically participated in the project of this Special Issue on “2D Ultra-Thin Carbon Films”, considering a globally unfavorable context characterized by (i) a myriad of publication options; (ii) strong pressure, by the highly competitive research (and researcher) funding and evaluation system, to publish in high impact factor journals, specifically for topics of worldwide interest; and (iii) all sorts of restrictions imposed by the sanitary crisis [...]
      Citation: C
      PubDate: 2021-03-25
      DOI: 10.3390/c7020030
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 31: sp2 Carbon Stable Radicals

    • Authors: Elena F. Sheka
      First page: 31
      Abstract: sp2 Nanocarbons such as fullerenes, carbon nanotubes, and graphene molecules are not only open-shell species, but spatially extended, due to which their chemistry is quite specific. Cogently revealed dependence of the final products composition on size and shape of the carbons in use as well as on the chemical prehistory is accumulated in a particular property—the stabilization of the species’ radical efficiency, thus providing the matter of stable radicals. If the feature is highly restricted and rarely available in ordinary chemistry, in the case of sp2 nanocarbons it is just an ordinary event providing, say, tons-in-mass stable radicals when either producing such widely used technological products as carbon black or dealing with deposits of natural sp2 carbons such as anthracite, shungite carbon, and other. Suggested in the paper is the consideration of stable radicals of sp2 nanocarbons from the standpoint of spin-delocalized topochemistry. Characterized in terms of the total and atomically partitioned number of effectively unpaired electrons as well as of the distribution of the latter over carbon atoms and described by selectively determined barriers of different reactions exhibiting topological essence of intermolecular interaction, sp2 nanocarbons reveal a peculiar topokinetics that lays the foundation of the stability of their radical properties.
      Citation: C
      PubDate: 2021-03-26
      DOI: 10.3390/c7020031
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 32: Preparation of Pt/CNT Thin-Film Electrodes by
           Electrochemical Potential Pulse Deposition for Methanol Oxidation

    • Authors: Jose Quintero-Ruiz, Ramiro Ruiz-Rosas, Javier Quílez-Bermejo, David Salinas-Torres, Diego Cazorla-Amorós, Emilia Morallón
      First page: 32
      Abstract: High-quality performance of catalysts is increasingly required to meet industry exigencies. However, chemical synthesis is often insufficient to maximize the potential properties of the catalysts. On the other hand, electrochemical synthesis has arisen as a promising alternative to overcome these limitations and provide precise control in the preparation of catalysts. In this sense, this work involved the well-controlled electrochemical synthesis of a catalyst based on platinum nanoparticle deposition on carbon nanotubes using only electrochemical treatments. Thin films of functionalized carbon nanotubes were cast onto the surface of a glassy carbon electrode using potential pulsed electrodeposition, resulting in a better distribution of the carbon nanotubes on the electrode when comparing with traditional methods. Then, platinum nanoparticles were electrodeposited on the carbon nanotube-modified electrode. To check the performance of the catalyst and the relevance of the electrochemical synthesis treatments, the samples were analyzed as electrocatalysts towards methanol electrooxidation, showing an important improvement in the catalytic activity in comparison with electrodes that were prepared by traditional methodologies.
      Citation: C
      PubDate: 2021-03-26
      DOI: 10.3390/c7020032
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 33: Investigation of the Effects of Multi-Wall and
           Single-Wall Carbon Nanotubes Concentration on the Properties of ABS
           Nanocomposites

    • Authors: Brenda Janett Alonso Gutierrez, Sithiprumnea Dul, Alessandro Pegoretti, Jaime Alvarez-Quintana, Luca Fambri
      First page: 33
      Abstract: The effects of two types of carbon nanotubes, namely multiwall (MWCNT) and single-wall (SWCNT) carbon nanotube, on the thermal and mechanical properties of acrylonitrile-butadiene-styrene (ABS) nanocomposites, have been investigated. ABS filled-CNT nanocomposites with various filler loadings of 5–10 wt% were properly produced by a solvent-free process in blend compounding at 190 °C. Compression moulded plates and extruded filaments were obtained at 190 °C and 230 °C, respectively. Melt flow index (MFI), shore hardness, Vicat temperature, differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) were performed to characterize and compared the different CNT nanocomposites. ABS/SWCNT composite filaments showed higher tensile properties (i.e., stiffness and strength), than ABS/MWCNT. The electrical resistivity of ABS/SWCNT and ABS/MWCNT filaments decreased to 0.19 Ω.cm and 0.65 Ω.cm for nanocomposites with 10 wt% of nanofillers; a power law was presented to describe the electrical resistivity of composites as a function of the CNTs content. A final comparative parameter regarding melt flow, stiffness and conductivity was also evaluated for understanding the combined effects of the nanofillers. SWCNT nanocomposites exhibited better overall cumulative results than MWCNT nanocomposites.
      Citation: C
      PubDate: 2021-03-27
      DOI: 10.3390/c7020033
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 34: A Threshold Line for Safe Geologic CO2 Storage Based
           on Field Measurement of Soil CO2 Flux

    • Authors: Takashi Kuriyama, Phung Quoc Huy, Salmawati Salmawati, Kyuro Sasaki
      First page: 34
      Abstract: Carbon capture and storage (CCS) is an established and verified technology that can implement zero emissions on a large enough scale to limit temperature rise to below 2 °C, as stipulated in the Paris Agreement. However, leakage from CCS sites must be monitored to ensure containment performance. Surface monitoring of carbon dioxide (CO2) concentrations at onshore CCS sites is one method to locate and quantify CCS site leakage. Employing soil accumulation chambers, we have established baseline data for the natural flux of CO2 as a threshold alert to detect CO2 leakage flux to ensure the safety of onshore CCS sites. Within this context, we conducted on-site CO2 measurements at three different locations (A, B, and C) on the INAS test field at the Ito campus, Kyushu University (Japan). Furthermore, we developed a specific measurement system based on the closed-chamber method to continuously measure CO2 flux from soil and to investigate the correlation between CO2 flux from the soil surface and various parameters, including environmental factors and soil sample characteristics. In addition, gas permeability and the effect of different locations on soil CO2 flux are discussed in this study. Finally, we present an equation for estimating the soil CO2 flux used in the INAS field site that includes environmental factors and soil characteristics. This equation assists in defining the threshold line for an alert condition related to CO2 leakage at onshore CCS sites.
      Citation: C
      PubDate: 2021-03-27
      DOI: 10.3390/c7020034
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 35: A Review on van der Waals Boron Nitride Quantum Dots

    • Authors: Amit Acharya, Sambhawana Sharma, Xiuling Liu, Dongyan Zhang, Yoke Khin Yap
      First page: 35
      Abstract: Boron nitride quantum dots (BNQDs) have gained increasing attention for their versatile fluorescent, optoelectronic, chemical, and biochemical properties. During the past few years, significant progress has been demonstrated, started from theoretical modeling to actual application. Many interesting properties and applications have been reported, such as excitation-dependent emission (and, in some cases, non-excitation dependent), chemical functionalization, bioimaging, phototherapy, photocatalysis, chemical, and biological sensing. An overview of this early-stage research development of BNQDs is presented in this article. We have prepared un-bias assessments on various synthesis methods, property analysis, and applications of BNQDs here, and provided our perspective on the development of these emerging nanomaterials for years to come.
      Citation: C
      PubDate: 2021-03-27
      DOI: 10.3390/c7020035
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 36: Morphological Characterization and Lumped Element
           Model of Graphene and Biochar Thick Films

    • Authors: Muhammad Yasir, Pietro Zaccagnini, Gianluca Palmara, Francesca Frascella, Niccolò Paccotti, Patrizia Savi
      First page: 36
      Abstract: Carbon based materials exhibit interesting mechanical, thermal and electrical properties which make them excellent contenders for use as fillers in composites as film. Graphene has been vastly used among the carbon-based materials. More recently eco-friendly carbon-based materials like biochar have emerged. The deployment of carbon-based materials in films needs to be studied since films are more versatile and permit the exploitation of electrical properties of such materials over circuits and systems. Typical circuits and systems exploiting electrical properties of novel materials perform a number of applications including sensing, detection, tunable devices and energy harvesting. In this paper, films composed of 9:1 graphene or biochar are deployed on a microstrip line. The morphological properties of graphene and biochar and their respective films are studied with Raman spectra and Field Emission Scanning Electron Microscope (FESEM). The electrical properties (four-point probe measurements and scattering parameter measurements) of the films. Low frequency measurements are used as starting point for circuit models estimating the lumped impedance of the films. From the morphological characterization it is shown that biochar films appear as granulates carbonaceous materials whereas graphene films contains several flakes forming a network. From the low frequency measurements and microwave characterization it is seen that graphene films are more conductive as compared to biochar films. In many applications, it is useful to know the surface impedance of the film since it varies on interaction with any external stimulus (variation of pressure, humidity, gas, etc.).
      Citation: C
      PubDate: 2021-03-27
      DOI: 10.3390/c7020036
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 37: Impact of Graphene or Reduced Graphene Oxide on
           Performance of Thermoelectric Composites

    • Authors: Olena Okhay, Alexander Tkach
      First page: 37
      Abstract: In recent years, worldwide research has been focused on clean and sustainable energy sources that can respond to the exponentially rising energy demands of humankind. The harvesting of unused heat in relation to automotive exhaustion, industrial processes, and home heating is one possible way of enabling the transformation from a fossil fuel-based society to a low-carbon socioeconomic epoch. Thermoelectric (TE) generators can convert heat to electrical energy thanks to high-performance TE materials that work via Seebeck effects when electricity appears between the cold part and the hot part of these materials. High figure of merit (ZT) TE material is characterized by high electrical conductivity and Seebeck coefficient, together with low thermal conductivity. This article aims to summarize ZT values reported for chalcogenides, skutterudites, and metal oxides with graphene (G) or reduced graphene oxide (rGO), and intends to understand the relationship between the addition of G-rGO to composites and ZT variation. In a majority of the publications, ZT value increases with the addition of G/rGO, although the relative growth of ZT varies for different material families, as well as inside the same group of materials, with it often being related not to a G/rGO amount but with the quality of the composite.
      Citation: C
      PubDate: 2021-04-21
      DOI: 10.3390/c7020037
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 38: Polyamide 12/Multiwalled Carbon Nanotube and Carbon
           Black Nanocomposites Manufactured by 3D Printing Fused Filament
           Fabrication: A Comparison of the Electrical, Thermoelectric, and
           Mechanical Properties

    • Authors: Nectarios Vidakis, Markos Petousis, Lazaros Tzounis, Emmanuel Velidakis, Nikolaos Mountakis, Sotirios A. Grammatikos
      First page: 38
      Abstract: In this study, nanocomposites with polyamide 12 (PA12) as the polymer matrix and multiwalled carbon nanotubes (MWCNTs) and carbon black (CB) at different loadings (2.5, 5.0, and 10.0 wt.%) as fillers, were produced in 3D printing filament form by melt mixing extrusion process. The filament was then used to build specimens with the fused filament fabrication (FFF) three-dimensional (3D) printing process. The aim was to produce by FFF 3D printing, electrically conductive and thermoelectric functional specimens with enhanced mechanical properties. All nanocomposites’ samples were electrically conductive at filler loadings above the electrical percolation threshold. The highest thermoelectric performance was obtained for the PA12/CNT nanocomposite at 10.0 wt.%. The static tensile and flexural mechanical properties, as well as the Charpy’s impact and Vickers microhardness, were determined. The highest improvement in mechanical properties was observed for the PA12/CNT nanocomposites at 5.0 wt.% filler loading. The fracture mechanisms were identified by fractographic analyses of scanning electron microscopy (SEM) images acquired from fractured surfaces of tensile tested specimens. The nanocomposites produced could find a variety of applications such as; 3D-printed organic thermoelectric materials for plausible large-scale thermal energy harvesting applications, resistors for flexible circuitry, and piezoresistive sensors for strain sensing.
      Citation: C
      PubDate: 2021-04-23
      DOI: 10.3390/c7020038
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 39: Activated Carbon from Biomass Sustainable Sources

    • Authors: Yong X. Gan
      First page: 39
      Abstract: Biomass wastes are abundant around us. They are renewable and inexpensive. Product manufacturing from renewable resources has caught increasing interest recently. Activated carbon preparation from biomass resources, including various trees, leaves, plant roots, fruit peels, and grasses, is a good example. In this paper, an overview of activated carbon production from biomass resources will be given. The first part will be on the processing technologies. The second part will focus on the carbon activation methods. The third part will introduce the biomass resources. The fourth part will be on surface modification of activated carbon through the addition of various components. Finally, the development of product applications will be discussed with an emphasis on adsorption, filtration, water purification, energy conversions, and energy storage.
      Citation: C
      PubDate: 2021-04-27
      DOI: 10.3390/c7020039
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 40: Poly(Vinylamine) Derived N-Doped C-Dots with
           Antimicrobial and Antibiofilm Activities

    • Authors: Semiha Duygu Sutekin, Mehtap Sahiner, Selin Sagbas Suner, Sahin Demirci, Olgun Güven, Nurettin Sahiner
      First page: 40
      Abstract: Nitrogen-doped carbon dots (N-doped C-dots) was synthesized by using poly(vinyl amine) (PVAm) as a nitrogen source and citric acid (CA) as a carbon source via the hydrothermal method. Various weight ratios of CA and PVAm (CA:PVAm) were used to synthesize N-doped C-dots. The N-doped C-dots revealed emission at 440 nm with excitation at 360 nm and were found to increase the fluorescence intensity with an increase in the amount of PVAm. The blood compatibility studies revealed no significant hemolysis for N-doped C-dots that were prepared at different ratios of CA:PVAm for up to 500 μg/mL concentration with the hemolysis ratio of 1.96% and the minimum blood clotting index of 88.9%. N-doped C-dots were found to be more effective against Gram-positive bacteria than Gram-negative bacteria, with the highest potency on Bacillus subtilis (B. subtilis). The increase in the weight ratio of PVAm in feed during C-dots preparation from 1 to 3 leads to a decrease of the minimum bactericidal concentration (MBC) value from 6.25 to 0.75 mg/mL for B. subtilis. Antibiofilm ability of N-doped C-dots prepared by 1:3 ratio of CA:PVAm was found to reduce %biofilm inhibition and eradication- by more than half, at 0.78 mg/mL for E. coli and B. subtilis generated biofilms and almost destroyed at 25 mg/mL concentrations.
      Citation: C
      PubDate: 2021-04-27
      DOI: 10.3390/c7020040
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 41: Thermogravimetric Analysis (TGA) of Graphene
           Materials: Effect of Particle Size of Graphene, Graphene Oxide and
           Graphite on Thermal Parameters

    • Authors: Farzaneh Farivar, Pei Lay Yap, Ramesh Udayashankar Karunagaran, Dusan Losic
      First page: 41
      Abstract: Thermogravimetric analysis (TGA) has been recognized as a simple and reliable analytical tool for characterization of industrially manufactured graphene powders. Thermal properties of graphene are dependent on many parameters such as particle size, number of layers, defects and presence of oxygen groups to improve the reliability of this method for quality control of graphene materials, therefore it is important to explore the influence of these parameters. This paper presents a comprehensive TGA study to determine the influence of different particle size of the three key materials including graphene, graphene oxide and graphite on their thermal parameters such as carbon decomposition range and its temperature of maximum mass change rate (Tmax). Results showed that Tmax values derived from the TGA-DTG carbon combustion peaks of these materials increasing from GO (558–616 °C), to graphene (659–713 °C) and followed by graphite (841–949 °C) The Tmax values derived from their respective DTG carbon combustion peaks increased as their particle size increased (28.6–120.2 µm for GO, 7.6–73.4 for graphene and 24.2–148.8 µm for graphite). The linear relationship between the Tmax values and the particle size of graphene and their key impurities (graphite and GO) confirmed in this study endows the use of TGA technique with more confidence to evaluate bulk graphene-related materials (GRMs) at low-cost, rapid, reliable and simple diagnostic tool for improved quality control of industrially manufactured GRMs including detection of “fake” graphene.
      Citation: C
      PubDate: 2021-04-27
      DOI: 10.3390/c7020041
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 42: Towards Controlled Degradation of Poly(Lactic) Acid
           in Technical Applications

    • Authors: Teixeira, Eblagon, Miranda, R. Pereira, Figueiredo
      First page: 42
      Abstract: Environmental issues urge for the substitution of petrochemical-based raw materials with more environmentally friendly sources. The biggest advantages of PLA over non-biodegradable plastics are that it can be produced from natural sources (e.g., corn or sugarcane), and at the end of its lifetime it can be returned to the soil by being composted with microorganisms. PLA can easily substitute petroleum-based plastics in a wide range of applications in many commodity products, such as disposable tableware, packaging, films, and agricultural twines, partially contributing to limiting plastic waste accumulation. Unfortunately, the complete replacement of fossil fuel-based plastics such as polyethylene (PE) or poly(ethylene terephthalate) (PET) by PLA is hindered by its higher cost, and, more importantly, slower degradation as compared to other degradable polymers. Thus, to make PLA more commercially attractive, ways to accelerate its degradation are actively sought. Many good reviews deal with PLA production, applications, and degradation but only in the medical or pharmaceutical field. In this respect, the present review will focus on controlled PLA degradation and biodegradation in technical applications. The work will include the main degradation mechanisms of PLA, such as its biodegradation in water, soil, and compost, in addition to thermal- and photo-degradation. The topic is of particular interest to academia and industry, mainly because the wider application of PLA is mostly dependent on discovering effective ways of accelerating its biodegradation rate at the end of its service life without compromising its properties.
      Citation: C
      PubDate: 2021-04-30
      DOI: 10.3390/c7020042
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 43: Nanocomposite of Ellagic Acid with Multi-Walled
           Carbon Nanotubes for the Simultaneous Voltammetric Detection of Six
           Biomolecules

    • Authors: Najmeh Sabbaghi, Meissam Noroozifar, Kagan Kerman
      First page: 43
      Abstract: In this proof-of-concept study, a highly sensitive electrochemical sensor using a graphite paste electrode modified with ellagic acid and multi-walled carbon nanotubes (MGPE/MWCNTs-EA) was developed for the simultaneous determination of six biomolecules: ascorbic acid (AA), dopamine (DA), uric acid (UA), tryptophan (Trp), xanthine (XA), and caffeine (CA). Differential pulse voltammetry (DPV) was performed at a potential range from 0.1–1.2 V vs. Ag/AgCl in phosphate electrolyte (pH 2.0). The modified GPE enabled the simultaneous determination of biomolecules under investigation in human urine and blood serum samples with detection limits ranging from 11–91 nM with recoveries of 94.0–106.0%. The electrochemical performance of the modified GPE for the analytes was stable and reproducible and checked with standard high performance liquid chromatography technique. The data suggested that the modified GPE provided a promising platform for routine quantitative determination of the biomolecules under investigation in quality control studies of real samples collected from food and pharmaceutical products.
      Citation: C
      PubDate: 2021-05-03
      DOI: 10.3390/c7020043
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 44: Variable Temperature Synthesis of Tunable
           Flame-Generated Carbon Nanoparticles

    • Authors: Francesca Picca, Angela Di Pietro, Mario Commodo, Patrizia Minutolo, Andrea D’Anna
      First page: 44
      Abstract: In this study, flame-formed carbon nanoparticles of different nanostructures have been produced by changing the flame temperature. Raman spectroscopy has been used for the characterization of the carbon nanoparticles, while the particle size has been obtained by online measurements made by electrical mobility analysis. The results show that, in agreement with recent literature data, a large variety of carbon nanoparticles, with a different degree of graphitization, can be produced by changing the flame temperature. This methodology allows for the synthesis of very small carbon nanoparticles with a size of about 3-4 nm and with different graphitic orders. Under the perspective of the material synthesis process, the variable-temperature flame-synthesis of carbon nanoparticles appears as an attractive procedure for a cost-effective and easily scalable production of highly tunable carbon nanoparticles.
      Citation: C
      PubDate: 2021-05-06
      DOI: 10.3390/c7020044
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 45: Molybdenum Disulfide Quantum Dots: Properties,
           Synthesis, and Applications

    • Authors: Jeff Kabel, Sambhawana Sharma, Amit Acharya, Dongyan Zhang, Yoke Khin Yap
      First page: 45
      Abstract: Molybdenum disulfide quantum dots (MoS2 QDs) are a unique class of zero-dimensional (0D) van der Waals nanostructures. MoS2 QDs have attracted significant attention due to their unique optical, electronic, chemical, and biological properties due to the presence of edge states of these van der Waals QDs for various chemical functionalization. Their novel properties have enabled applications in many fields, including advanced electronics, electrocatalysis, and biomedicine. In this review, the various synthesis techniques, the novel properties, and the wide applications of MoS2 quantum dots are discussed in detail.
      Citation: C
      PubDate: 2021-05-08
      DOI: 10.3390/c7020045
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 46: The Performance of Fibrous CDC Electrodes in Aqueous
           and Non-Aqueous Electrolytes

    • Authors: Siret Malmberg, Mati Arulepp, Krista Laanemets, Maike Käärik, Ann Laheäär, Elvira Tarasova, Viktoria Vassiljeva, Illia Krasnou, Andres Krumme
      First page: 46
      Abstract: The aim of this study was to investigate the electrochemical behaviour of aqueous electrolytes on thin-layer (20 µm) nanoporous carbide-derived carbon (CDC) composite fibrous directly electrospun electrodes without further carbonisation. There have been previously investigated fibrous electrodes, which are produced by applying different post-treatment processes, however this makes the production of fibrous electrodes more expensive, complex and time consuming. Furthermore, in the present study high specific capacitance was achieved with directly electrospun nanoporous CDC-based fibrous electrodes in different neutral aqueous electrolytes. The benefit of fibrous electrodes is the advanced mechanical properties compared to the existing commercial electrode technologies based on pressure-rolled or slurry-cast powder mix electrodes. Such improved mechanical properties are preferred in more demanding applications, such as in the space industry. Electrospinning technology also allows for larger electrode production capacities without increased production costs. In addition to the influence of aqueous electrolyte chemical composition, the salt concentration effects and cycle stability with respect to organic electrolytes are investigated. Cyclic voltammetry (CV) measurements on electrospun electrodes showed the highest capacitance for asymmetrical cells with an aqueous 1 M NaNO3-H2O electrolyte. High CV capacitance was correlated with constant current charge–discharge (CC) data, for which a specific capacitance of 191 F g−1 for the positively charged electrode and 311 F g−1 for the negatively charged electrode was achieved. The investigation of electrolyte salt concentration on fibrous electrodes revealed the typical capacitance dependence on ionic conductivity with a peak capacitance at medium concentration levels. The cycle-life measurements of selected two-electrode test cells with aqueous and non-aqueous electrolytes revealed good stability of the electrospun electrodes.
      Citation: C
      PubDate: 2021-05-14
      DOI: 10.3390/c7020046
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 47: Porphyrin MOF-Derived Porous Carbons: Preparation and
           Applications

    • Authors: Flávio Figueira, Filipe A. Almeida Paz
      First page: 47
      Abstract: Metal–organic frameworks (MOFs) are crystalline materials with permanent porosity, composed of metal nodes and organic linkers whose well-ordered arrangement enables them to act as ideal templates to produce materials with a uniform distribution of heteroatom and metal elements. The hybrid nature of MOFs, well-defined pore structure, large surface area and tunable chemical composition of their precursors, led to the preparation of various MOF-derived porous carbons with controlled structures and compositions bearing some of the unique structural properties of the parent networks. In this regard, an important class of MOFs constructed with porphyrin ligands were described, playing significant roles in the metal distribution within the porous carbon material. The most striking early achievements using porphyrin-based MOF porous carbons are here summarized, including preparation methods and their transformation into materials for electrochemical reactions.
      Citation: C
      PubDate: 2021-05-15
      DOI: 10.3390/c7020047
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 48: Raman Spectroscopy Investigation of Graphene Oxide
           Reduction by Laser Scribing

    • Authors: Vittorio Scardaci, Giuseppe Compagnini
      First page: 48
      Abstract: Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.
      Citation: C
      PubDate: 2021-06-17
      DOI: 10.3390/c7020048
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 49: Fluorescent Nanodiamonds Synthesized in One-Step by
           Pulsed Laser Ablation of Graphite in Liquid-Nitrogen

    • Authors: Massimo Cazzanelli, Luca Basso, Claudio Cestari, Nicola Bazzanella, Enrico Moser, Michele Orlandi, Alessandro Piccoli, Antonio Miotello
      First page: 49
      Abstract: In this work, we present a relevant upgrade to the technique of pulsed laser ablation of fluorescent nanodiamonds (NDs), relying on an automatized graphite-target movement maintaining a constant level of liquid nitrogen over its surface during hours of deposition. Around 60 mg of NDs nanopowder was synthesized and optomagnetically characterized to assess its optical quality. Chemical purification of the ablated nanopowders, which removes the graphitic byproducts, permits to obtain pure fluorescent NDs with an efficiency of 7 ± 1% with respect to the total nanopowder mass. This value compares positively with the efficiency of other commercial NDs synthesis techniques such as detonation, cavitation, and high pressure–high temperature.
      Citation: C
      PubDate: 2021-06-21
      DOI: 10.3390/c7020049
      Issue No: Vol. 7, No. 2 (2021)
       
  • C, Vol. 7, Pages 4: Functionalized Graphene Quantum Dots Modulate
           Malignancy of Glioblastoma Multiforme by Downregulating Neurospheres
           Formation

    • Authors: Giordano Perini, Valentina Palmieri, Gabriele Ciasca, Aniello Primiano, Jacopo Gervasoni, Marco De Spirito, Massimiliano Papi
      First page: 4
      Abstract: Glioblastoma multiforme (GBM) is the most aggressive brain cancer. We previously demonstrated the effect of biocompatible surface functionalized graphene quantum dots (GQDs) on GBM cells as chemotherapy enhancers in combination with the antitumor drug doxorubicin (Dox). However, traditional two-dimensional cultures could not represent a reliable model of tumor behavior. In this work, we investigated the effect of carboxylated (COOH-GQDs), aminated (NH2-GQDs) and unfunctionalized GQDs on a three-dimensional model of neurospheres. Neurospheres are clusters of GBM cells, which formation is driven by the presence of a stem subpopulation involved in cancer malignancy. Tumor recurrence after surgical resection, chemotherapy and radiotherapy indeed depends on the presence of cancer cells with stem properties. We measured a significant reduction in number and size of neurospheres after two weeks of monitoring in the presence of COOH-GQDs and GQDs. Previous works pointed out how variations of membrane fluidity could affect membrane stability and cell-to-cell interactions, thus influencing cell clustering. Therefore, we measured changes in membrane fluidity after administration of GQDs. We found that COOH-GQDs and GQDs significantly increased membrane fluidity with respect to the treatment with NH2-GQDs or compared to untreated cells. Shifts in the phase of phospholipid bilayer were in accordance with the negative surface net charge of GQDs. We depicted a strong correlation between negatively charged GQDs-induced increase in membrane fluidity and the downregulation of neurospheres formation. Our results indicate that COOH-GQDs and GQDs significantly modulate tumor malignancy by increasing fluidity of cell membrane, with a consequent inhibition of cell-to-cell interaction.
      Citation: C
      PubDate: 2021-01-05
      DOI: 10.3390/c7010004
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 5: First-Principles Study of the Electronic Properties
           and Thermal Expansivity of a Hybrid 2D Carbon and Boron Nitride Material

    • Authors: Okikiola Olaniyan, Lyudmila V. Moskaleva
      First page: 5
      Abstract: In an attempt to push the boundary of miniaturization, there has been a rising interest in two-dimensional (2D) semiconductors with superior electronic, mechanical, and thermal properties as alternatives for silicon-based devices. Due to their fascinating properties resulting from lowering dimensionality, hexagonal boron nitride (h-BN) and graphene are considered promising candidates to be used in the next generation of high-performance devices. However, neither h-BN nor graphene is a semiconductor due to a zero bandgap in the one case and a too large bandgap in the other case. Here, we demonstrate from first-principles calculations that a hybrid 2D material formed by cross-linking alternating chains of carbon and boron nitride (HCBN) shows promising characteristics combining the thermal merits of graphene and h-BN while possessing the electronic structure characteristic of a semiconductor. Our calculations demonstrate that the thermal properties of HCBN are comparable to those of h-BN and graphene (parent systems). HCBN is dynamically stable and has a bandgap of 2.43 eV. At low temperatures, it exhibits smaller thermal contraction than the parent systems. However, beyond room temperature, in contrast to the parent systems, it has a positive but finitely small linear-thermal expansion coefficient. The calculated isothermal bulk modulus indicates that at high temperatures, HCBN is less compressible, whereas at low temperatures it is more compressible relative to the parent systems. The results of our study are important for the rational design of a 2D semiconductor with good thermal properties.
      Citation: C
      PubDate: 2021-01-12
      DOI: 10.3390/c7010005
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 6: Ionic Liquids for CO2 Capture and Reduction

    • Authors: Małgorzata E. Zakrzewska
      First page: 6
      Abstract: As pointed out in the description of this thematic issue of C, with the current atmospheric levels of carbon dioxide being above 400 ppm, there is a growing interest in recycling this greenhouse gas in the form of valuable compounds [...]
      Citation: C
      PubDate: 2021-01-13
      DOI: 10.3390/c7010006
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 7: Asymmetric Supercapacitors: Optical and Thermal
           Effects When Active Carbon Electrodes Are Embedded with Nano-Scale
           Semiconductor Dots

    • Authors: Haim Grebel
      First page: 7
      Abstract: Optical and thermal effects in asymmetric supercapacitors, whose active-carbon (AC) electrodes were embedded with nano-Si (n-Si) quantum dots (QD), are reported. We describe two structures: (1) p-n-like, obtained by using a polyethylimine (PEI) binder for the “n” electrode and a polyvinylpyrrolidone (PVP) binder for the “p” electrode; (2) a single component binder—poly(methyl methacrylate) (PMMA). In general, AC appears black to the naked eye and one may assume that it indiscriminately absorbs all light spectra. However, on top of a flat lossy spectrum, AC (from two manufacturers) exhibited two distinct absorption bands: one in the blue (~400 nm) and the other one in the near IR (~840 nm). The n-Si material accentuated the absorption in the blue and bleached the IR absorption. Both bands contributed to capacitance increase: (a) when using aqueous solution and a PMMA binder, the optical-related increased capacitance was 20% for low n-Si concentration and more than 100% for a high-concentration dose; (b) when using ion liquid (IL) electrolyte, the large, thermal capacitance increase (of ca. 40%) was comparable to the optical effect (of ca. 42%) and hence was assigned as an optically induced thermal effect. The experimental data point to an optically induced capacitance increase even in the absence of the n-Si dots. Overall, the experimental data suggest intriguing possibilities for optically controlled supercapacitors.
      Citation: C
      PubDate: 2021-01-15
      DOI: 10.3390/c7010007
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 8: Modifying Electronic and Elastic Properties of
           2-Dimensional [110] Diamond by Nitrogen Substitution

    • Authors: Teerachote Pakornchote, Annop Ektarawong, Udomsilp Pinsook, Thiti Bovornratanaraks
      First page: 8
      Abstract: One type of two-dimensional diamonds that are derived from [111] direction, so-called diamane, has been previously shown to be stabilized by N-substitution, where the passivation of dangling bonds is no longer needed. In the present work, we theoretically demonstrated that another type of two-dimensional diamonds derived from [110] direction exhibiting a washboard conformation can also be stabilized by N-substitution. Three structural models of washboard-like carbon nitrides with compositions of C6N2, C5N3, and C4N4 are studied together with the fully hydrogenated washboard-like diamane (C8H4). The result shows that the band gap of this type structure is only open the dangling bonds that are entirely diminished through N-substitution. By increasing the N content, the C11 and C22 are softer and the C33 is stiffer where their bulk modulus are in the same order, which is approximately 550 GPa. When comparing with the hydrogenated phase, the N-substituted phases have higher elastic constants and bulk modulus, suggesting that they are possibly harder than the fully hydrogenated diamane.
      Citation: C
      PubDate: 2021-01-21
      DOI: 10.3390/c7010008
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 9: Progress on Diamane and Diamanoid Thin Film
           Pressureless Synthesis

    • Authors: Fabrice Piazza, Marc Monthioux, Pascal Puech, Iann C. Gerber, Kathleen Gough
      First page: 9
      Abstract: Nanometer-thick and crystalline sp3-bonded carbon sheets are promising new wide band-gap semiconducting materials for electronics, photonics, and medical devices. Diamane was prepared from the exposure of bi-layer graphene to hydrogen radicals produced by the hot-filament process at low pressure and temperature. A sharp sp3-bonded carbon stretching mode was observed in ultraviolet Raman spectra at around 1344–1367 cm−1 while no sp2-bonded carbon peak was simultaneously detected. By replacing bi-layer graphene with few-layer graphene, diamanoid/graphene hybrids were formed from the partial conversion of few-layer graphene, due to the prevalent Bernal stacking sequence. Raman spectroscopy, electron diffraction, and Density Functional Theory calculations show that partial conversion generates twisted bi-layer graphene located at the interface between the upper diamanoid domain and the non-converted graphenic domain underneath. Carbon-hydrogen bonding in the basal plane of hydrogenated few-layer graphene, where carbon is bonded to a single hydrogen over an area of 150 μm2, was directly evidenced by Fourier transform infrared microscopy and the actual full hydrogenation of diamane was supported by first-principle calculations. Those results open the door to large-scale production of diamane, diamanoids, and diamanoid/graphene hybrids.
      Citation: C
      PubDate: 2021-01-23
      DOI: 10.3390/c7010009
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 10: Raman Spectroscopy of Twisted Bilayer Graphene

    • Authors: Marcus V. O. Moutinho, Pedro Venezuela, Marcos A. Pimenta
      First page: 10
      Abstract: When two periodic two-dimensional structures are superposed, any mismatch rotation angle between the layers generates a Moiré pattern superlattice, whose size depends on the twisting angle θ. If the layers are composed by different materials, this effect is also dependent on the lattice parameters of each layer. Moiré superlattices are commonly observed in bilayer graphene, where the mismatch angle between layers can be produced by growing twisted bilayer graphene (TBG) samples by CVD or folding the monolayer back upon itself. In TBG, it was shown that the coupling between the Dirac cones of the two layers gives rise to van Hove singularities (vHs) in the density of electronic states, whose energies vary with θ. The understanding of the behavior of electrons and their interactions with phonons in atomically thin heterostructures is crucial for the engineering of novel 2D devices. Raman spectroscopy has been often used to characterize twisted bilayer graphene and graphene heterostructures. Here, we review the main important effects in the Raman spectra of TBG discussing firstly the appearance of new peaks in the spectra associated with phonons with wavevectors within the interior of the Brillouin zone of graphene corresponding to the reciprocal unit vectors of the Moiré superlattice, and that are folded to the center of the reduced Brillouin Zone (BZ) becoming Raman active. Another important effect is the giant enhancement of G band intensity of TBG that occurs only in a narrow range of laser excitation energies and for a given twisting angle. Results show that the vHs in the density of states is not only related to the folding of the commensurate BZ, but mainly associated with the Moiré pattern that does not necessarily have a translational symmetry. Finally, we show that there are two different resonance mechanisms that activate the appearance of the extra peaks: the intralayer and interlayer electron–phonon processes, involving electrons of the same layer or from different layers, respectively. Both effects are observed for twisted bilayer graphene, but Raman spectroscopy can also be used to probe the intralayer process in any kind of graphene-based heterostructure, like in the graphene/h-BN junctions.
      Citation: C
      PubDate: 2021-01-26
      DOI: 10.3390/c7010010
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 11: Surface Charge Effects on Adsorption of Solutes by
           Poplar and Elm Biochars

    • Authors: Steven C. Peterson, Sanghoon Kim, Jason Adkins
      First page: 11
      Abstract: Elm and poplar are two tree species that can provide a large amount of low-value feedstock for biochar production due to their rapid growth rate (poplar), and susceptibility to disease and/or infestation (both elm and poplar). Biochar has been studied recently as filtration medium for water purification, as it provides a renewable alternative to activated carbon. In this work, the adsorption efficiency of biochars made from elm and poplar as a function of pyrolysis temperature were studied by ultraviolet (UV) adsorption of dyes with positive, neutral, and negative charges to determine what factors had the greatest effect on adsorption of these dyes. It was found that conductivity of the biochars increased with pyrolysis temperature, and that this factor was more important than surface area in terms of adsorbing charged dyes. Both elm and poplar biochars were not effective in adsorbing neutral dyes. This research demonstrates that elm and poplar biochars adsorb charged (either positively or negatively) solutes more efficiently than uncharged ones because they carry both charges themselves. Therefore, these biochars would make excellent candidates as renewable filtration media for charged contaminants.
      Citation: C
      PubDate: 2021-01-26
      DOI: 10.3390/c7010011
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 12: Stabilization and Carbonization of PAN Nanofiber Mats
           Electrospun on Metal Substrates

    • Authors: Jan Lukas Storck, Bennet Brockhagen, Timo Grothe, Lilia Sabantina, Bernhard Kaltschmidt, Khorolsuren Tuvshinbayar, Laura Braun, Ewin Tanzli, Andreas Hütten, Andrea Ehrmann
      First page: 12
      Abstract: Polyacrylonitrile (PAN) nanofiber mats are typical precursors for carbon nanofibers. They can be fixed or even elongated during stabilization and subsequent carbonization to gain straight, mechanically robust carbon nanofibers. These processes necessitate additional equipment or are—if the nanofiber mats are just fixed at the edges—prone to resulting in the specimens breaking, due to an uneven force distribution. Hence, we showed in a previous study that electrospinning PAN on aluminum foils and stabilizing them fixed on these substrates, is a suitable solution to keep the desired morphology after stabilization and incipient carbonization. Here, we report on the influence of different metallic and semiconductor substrates on the physical and chemical properties of the nanofiber mats after stabilization and carbonization at temperatures up to 1200 °C. For stabilization on a metal substrate, an optimum stabilization temperature of slightly above 240 °C was found, approached with a heating rate of 0.25 K/min. Independent from the substrate material, SEM images revealed less defect fibers in the nanofiber mats stabilized and incipiently carbonized on a metal foil. Finally, high-temperature carbonization on different substrates is shown to allow for producing metal/carbon nano-composites.
      Citation: C
      PubDate: 2021-01-27
      DOI: 10.3390/c7010012
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 13: Symmetrical Derivative of Anthrone as a Novel
           Receptor for Mercury Ions: Enhanced Performance of Modified Screen-Printed
           Electrode

    • Authors: Kaur, Mittal, Kumar SK, Kumar, Kumar, Metters, Banks
      First page: 13
      Abstract: Voltammetric sensor using a symmetrical derivative of anthrone3 (1,7-diamino-3,9-dibutyl benzo[1,2,3-de:4,5,6-d’e’]diquinoline-2,8(3H,9H)-dione) (SPE-A) has been developed as a probe for Hg(II) ions. Performance of the probe as screen-printed electrode modified with the receptor (SPE-A) has been compared with anthrone3 in solution phase, using 1:1 water-acetonitrile solvent system. Anthrone3 displayed an electrochemically quasi-reversible nature in voltammograms with both the systems and is presented as a novel disposable voltammetric sensor for mercury ions. Upon interaction with cations, both the electrode systems showed sensitivity towards Hg2+ ions with a lower detection limit of 0.61 µM. The magnitude of the voltammetric current with the SPE-A exhibited three times the current obtained with a bare glassy carbon electrode (GC). Kinetic performance of the SPE-A electrode is better than the GC electrode. The morphological studies indicate reusability of the electrodes.
      Citation: C
      PubDate: 2021-01-27
      DOI: 10.3390/c7010013
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 14: Acknowledgment to Reviewers of C in 2020

    • Authors: C Editorial Office C Editorial Office
      First page: 14
      Abstract: Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that C maintains its standards for the high quality of its published papers [...]
      Citation: C
      PubDate: 2021-01-28
      DOI: 10.3390/c7010014
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 15: Design of Porous Carbons for Supercapacitor
           Applications for Different Organic Solvent-Electrolytes

    • Authors: Joshua Bates, Foivos Markoulidis, Constantina Lekakou, Giuliano M. Laudone
      First page: 15
      Abstract: The challenge of optimizing the pore size distribution of porous electrodes for different electrolytes is encountered in supercapacitors, lithium-ion capacitors and hybridized battery-supercapacitor devices. A volume-averaged continuum model of ion transport, taking into account the pore size distribution, is employed for the design of porous electrodes for electrochemical double-layer capacitors (EDLCs) in this study. After validation against experimental data, computer simulations investigate two types of porous electrodes, an activated carbon coating and an activated carbon fabric, and three electrolytes: 1.5 M TEABF4 in acetonitrile (AN), 1.5 M TEABF4 in propylene carbonate (PC), and 1 M LiPF6 in ethylene carbonate:ethyl methyl carbonate (EC:EMC) 1:1 v/v. The design exercise concluded that it is important that the porous electrode has a large specific area in terms of micropores larger than the largest desolvated ion, to achieve high specific capacity, and a good proportion of mesopores larger than the largest solvated ion to ensure fast ion transport and accessibility of the micropores.
      Citation: C
      PubDate: 2021-01-29
      DOI: 10.3390/c7010015
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 16: Energy Absorption in Carbon Fiber Composites with
           Holes under Quasi-Static Loading

    • Authors: Omar Alhyari, Golam Newaz
      First page: 16
      Abstract: Composite tubular structures have shown promise as energy absorbers in the automobile industry. This paper investigates the energy absorption characteristics of carbon fiber reinforced plastic (CFRP) tubes with pre-existing holes. Holes may represent an extreme case of impact damage that perforates the tube, e.g., stones from road surface impacting the tubes. Tubes with holes represent more conservative performance characteristics, since impact damage of the same size will have residual material, which may carry some load. Tubes with holes can provide the lower limit of CFRP tube performance under axial crushing relative to impact damaged tubes with perforation diameter close to the hole diameter. In this study, tubes with lay-up of [05/902/04] with one and two holes in defined locations and different diameters are experimentally studied under quasi-static loading. It was found that specific energy absorption (SEA) reduces by 50% with one or two holes of 15 mm size, 100 mm from top of the tube. The SEA reduction is about 60% lower than the regular tube when the diameter of the hole is 20 mm located at 100 mm from top. The most severe reduction occurs if the location of single or double holes are 75 mm from the top. In this case, a SEA reduction of 75% can be expected. Results indicate that holes can significantly alter the energy absorption capability of the tubes. It is also clear that in axial crushing of composite tubes, the location of the hole (100 to 75 mm) appears to create more pronounced effect than the size of the hole itself (15 vs. 20 mm) for the cases investigated. The failure modes for tubes with holes seem to preserve similar damage modes with delamination, frond creation, and brittle fracture, which is typically observed in regular composite tubes under axial crushing load. This is due to primarily front end crushing, which dominates the failure modes, while hole induced damage occurs later.
      Citation: C
      PubDate: 2021-02-01
      DOI: 10.3390/c7010016
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 17: Fully Hydrogenated and Fluorinated
           Bigraphenes–Diamanes: Theoretical and Experimental Studies

    • Authors: Leonid A. Chernozatonskii, Victor A. Demin, Dmitry G. Kvashnin
      First page: 17
      Abstract: Diamanes are 2D diamond-like films that are nanometers in thickness. Diamanes can exist as bilayer or multilayer graphene with various modes of stacking and interlayer covalent sp3 bonds. The term “diamane” is used broadly for a variety of diamond-like materials at the nanoscale, from individual diamond clusters to nanocrystal films. A short overview of recent progress in the investigation of diamanes, starting from the first theoretical predictions to practical realization, is presented. The results of both theoretical and experimental studies on diamanes with various atomic structures and types of functionalization are considered. It is shown that diamanes are stronger than graphene and graphane and have wide bandgaps ranging from 3.1 to 4.5 eV depending on the structure. Diamane-like structures have been obtained using different experimental techniques, and their structures have been determined by Raman spectroscopy. The potential applications of these carbon nanostructures are briefly reviewed.
      Citation: C
      PubDate: 2021-02-02
      DOI: 10.3390/c7010017
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 18: Carbon Nanotubes Transform Soft Gellan Gum Hydrogels
           into Hybrid Organic–Inorganic Coatings with Excellent Cell Growth
           Capability

    • Authors: Anatolii Abalymov, Louis Van der Meeren, Dmitry Volodkin, Bogdan Parakhonskiy, Andre G. Skirtach
      First page: 18
      Abstract: Carbone nanotubes (CNTs) possess distinct properties, for example, hardness, which is very complementary to biologically relevant soft polymeric and protein materials. Combining CNTs with bio-interfaces leads to obtaining new materials with advanced properties. In this work, we have designed novel organic-inorganic hybrid coatings by combining CNTs with gellan gum (GG) hydrogels. The surface topography of the samples is investigated using scanning electron microscopy and atomic force microscopy. Mechanical properties of synthesized hybrid materials are both assessed at the macro-scale and mapped at the nanoscale. A clear correlation between the CNT concentration and the hardness of the coatings is revealed. Cell culture studies show that effective cell growth is achieved at the CNT concentration of 15 mg/mL. The presented materials can open new perspectives for hybrid bio-interfaces and can serve as a platform for advanced cell culture.
      Citation: C
      PubDate: 2021-02-04
      DOI: 10.3390/c7010018
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 19: Carbon-Based Nanomaterials for Delivery of
           Biologicals and Therapeutics: A Cutting-Edge Technology

    • Authors: Alok Mahor, Prem Prakash Singh, Peeyush Bharadwaj, Neeraj Sharma, Surabhi Yadav, Jessica M. Rosenholm, Kuldeep K. Bansal
      First page: 19
      Abstract: After hydrogen and oxygen, carbon is the third most abundant component present in the cosmos with excellent characteristic features of binding to itself and nearly all elements. Since ancient times, carbon-based materials such as graphite, charcoal, and carbon black have been utilized for writing and drawing materials. As these materials possess excellent chemical, mechanical, electrical, and thermal features, they have been readily engineered into carbon-based nanomaterials (CNMs) such as carbon nanotubes, graphene oxide, graphene quantum dots, nanodiamonds, fullerenes, carbon nano-onions, and so forth. These materials are now widely explored in biomedical applications. Thus, the emergence of CNMs has opened up a gateway for the detection, delivery, and treatment of a multitude of diseases. They are being actively researched for applications within tissue engineering, as vaccine vectors, and for the delivery of therapeutics to the immune system. This review focuses on the recent advances in various types of CNMs, their fabrication techniques, and their application in the delivery of therapeutics both in vitro and in vivo. The review also focuses on the toxicity concern of the CNMs and the possible remedies to tackle the toxicity issues. Concluding remarks emphasize all the CNMs discussed in the review over their possible biomedical applications, while the future perspectives section discusses the approaches to bring CNMs into the mainstream of clinical trials and their therapeutic applications.
      Citation: C
      PubDate: 2021-02-05
      DOI: 10.3390/c7010019
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 20: Preparation and Applications of Fluorinated Graphenes

    • Authors: Yasser Ahmad, Nicolas Batisse, Xianjue Chen, Marc Dubois
      First page: 20
      Abstract: The present review focuses on the numerous routes for the preparation of fluorinated graphene (FG) according to the starting materials. Two strategies are considered: (i) addition of fluorine atoms on graphenes of various nature and quality and (ii) exfoliation of graphite fluoride. Chemical bonding in fluorinated graphene, related properties and a selection of applications for lubrication, energy storage, and gas sensing will then be discussed.
      Citation: C
      PubDate: 2021-02-07
      DOI: 10.3390/c7010020
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 21: A Comparative Study of Aromatization Catalysts: The
           Advantage of Hybrid Oxy/Carbides and Platinum-Catalysts Based on Carbon
           Gels

    • Authors: Luisa M. Pastrana-Martínez, Sergio Morales-Torres, Francisco J. Maldonado-Hódar
      First page: 21
      Abstract: This manuscript is focused on the relationship between sol-gel synthesis processes and the development of new active phases with fitted morphology, porosity and surface chemistry. The influence of the above parameters on the catalytic performance of the prepared materials for the aromatization of n-hexane to benzene is also evaluated. Different series of catalysts were prepared, either using noble metals (i.e., Pt) or metal oxides (i.e., Mo, W), as active phases. In both cases, the catalytic performance and stability of classical aromatization catalysts was significantly improved. Interesting one-pot carboreduction process of the metal oxide during carbonization is suggested as a real alternative for the preparation of high-performance aromatization catalysts, leading to the formation of less acidic and non-stoichiometric oxides and carbides.
      Citation: C
      PubDate: 2021-02-12
      DOI: 10.3390/c7010021
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 22: Anisotropic Magnetism in Gradient Porous Carbon
           Composite Aerogels

    • Authors: Bahner, Hug, Polarz
      First page: 22
      Abstract: Porosity is of high importance for functional materials, as it allows for high surface areas and the accessibility of materials. While the fundamental interplay between different pore sizes and functionalities is quite well understood, few studies on gradually changing properties in a material exist. To date, only a few examples of such materials have been synthesized successfully. Herein, we present a facile method for synthesizing macroscopic carbon aerogels with locally changing pore sizes and functionalities. We used ultracentrifugation to fractionate differently functionalized and sized polystyrene nanoparticles. The assembly into gradient templates was conducted in a resorcinol–formaldehyde (RF) sol, which acted as a liquid phase and carbon precursor. We show that the modification of nanoparticles and a sol–gel precursor is a powerful tool for introducing dopants (sulfur and phosphorous) and metal nanoparticles (e.g., Ni) into gradient porous carbons formed during the carbonization of the RF sol. Understanding the underlying interactions between particles and precursors will lead to a plethora of possibilities in the material design of complex functionally graded materials. We showed this by exchanging parts of the template with magnetite–polystyrene composites as templating nanoparticles. This led to the incorporation of magnetite nanoparticles in the formed gradient porous carbon aerogels. Finally, gradually increasing concentrations of magnetite were obtained, ultimately leading to macroscopic carbon aerogels with locally changing magnetic properties, while the graded porosity was maintained.
      Citation: C
      PubDate: 2021-02-13
      DOI: 10.3390/c7010022
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 23: Removal of Lead by Oxidized Graphite

    • Authors: Namasivayam Selvanantharajah, Poobalasuntharam Iyngaran, Poobalasingam Abiman, Navaratnarajah Kuganathan
      First page: 23
      Abstract: Lead ion adsorption on the surfaces of pristine and oxidized graphite is studied quantitatively using X-ray photoelectron spectroscopy (XPS) and standard electrochemical measurements. The XPS analysis confirmed the oxidation of graphite, yielding a final composite consisting of 15.97% of oxygen and 84.03% of carbon in comparison with the pristine graphite powder consisting of 6.13% oxygen and 93.87% carbon. The adsorption of lead (II) ion was confirmed by the peaks observed at 138 eV and 143.8 eV, associated with the emissions from Pb4f 7/2 and Pb4f 5/2, respectively. The effective concentration of Pb2+ ion and the optimum dosage of oxidized graphite were calculated to be 400 μM and 200 mg, respectively. Adsorption capacity of bare graphite was 41.18%, whereas that of oxidized graphite was 73.3%. The present results show that graphite oxide is a candidate material for the adsorption of Pb2+ ion from water.
      Citation: C
      PubDate: 2021-02-20
      DOI: 10.3390/c7010023
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 24: C—Journal of Carbon Research: 300th
           Publications Milestone

    • Authors: Craig E. Banks, Jandro L. Abot
      First page: 24
      Abstract: The C—Journal of Carbon Research (
      ISSN 2311-5629) is quite pleased to announce the publication of its 300th article [...]
      Citation: C
      PubDate: 2021-02-20
      DOI: 10.3390/c7010024
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 25: Selection of Mixed Amines in the CO2 Capture Process

    • Authors: Pao-Chi Chen, Hsun-Huang Cho, Jyun-Hong Jhuang, Cheng-Hao Ku
      First page: 25
      Abstract: In order to select the best mixed amines in the CO2 capture process, the absorption of CO2 in mixed amines was explored at the required concentrations by using monoethanolamine (MEA) as a basic solvent, mixed with diisopropanolamine (DIPA), triethanolamine (TEA), 2-amino-2-methyl-1-propanol (AMP), and piperazine (PZ). Here, a bubble column was used as the scrubber, and a continuous operation was adopted. The Taguchi method was used for the experimental design. The conditional factors included the type of mixed amine (A), the ratio of the mixed amines (B), the liquid feed flow (C), the gas-flow rate (D), and the concentration of mixed amines (E). There were four levels, respectively, and a total of 16 experiments. The absorption efficiency (EF), absorption rate (RA), overall mass transfer coefficient (KGa), and scrubbing factor (<i>ϕ</i>) were used as indicators and were determined in a steady-state by the mass balance and two-film models. According to the Taguchi analysis, the importance of the parameters and the optimum conditions were obtained. In terms of the absorption efficiency (EF), the absorption rate (absorption factor) (RA/<i>ϕ</i>), and the overall mass transfer coefficient (KGa), the order of importance is D > E > A > B > C, D > E > C > B > A, and D > E > C > A > B, respectively, and the optimum conditions are A1B4C4D3E3, A1B3C4D4E2, A4B2C3D4E4, and A1B1C1D4E1. The optimum condition validation results showed that the optimal values of EF, RA, and KGa are 100%, 30.69 × 10−4 mol/s·L, 1.540 l/s, and 0.269, respectively. With regard to the selection of mixed amine, it was found that the mixed amine (MEA + AMP) performed the best in the CO2 capture process.
      Citation: C
      PubDate: 2021-02-24
      DOI: 10.3390/c7010025
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 26: A New Composite Material on the Base of Carbon
           Nanotubes and Boron Clusters B12 as the Base for High-Performance
           Supercapacitor Electrodes

    • Authors: Dmitry A. Kolosov, Olga E. Glukhova
      First page: 26
      Abstract: We explore the quantum capacitance, stability, and electronic properties of single-walled carbon nanotubes decorated with B12 icosahedral boron clusters by first-principle calculation methods implemented in the SIESTA code. After the optimization of the built supercells, the B12 clusters formed bonds with the walls of the carbon nanotubes and demonstrated metallic properties in all cases. The network of carbon nanotubes with its large area and branched surface is able to increase the capacity of the electric double-layer capacity, but the low quantum capacity of each nanotube in this network limits its application in supercapacitors. We found that the addition of boron clusters to both the outer and inner walls increased the quantum capacitance of carbon nanotubes. The calculation of the transmission function near the Fermi energy showed an increase in the conductivity of supercells. It was also found that an increase in the concentration of boron clusters in the structure led to a decrease in the heat of formation that positively affects the stability of supercells. The calculation of the specific charge density showed that with an increase in the boron concentration, the considered material demonstrated the properties of an asymmetric electrode.
      Citation: C
      PubDate: 2021-02-25
      DOI: 10.3390/c7010026
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 27: The Role of Surface Chemistry and Polyethylenimine
           Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut
           Shells

    • Authors: Victoria A. Smith, Juster F. A. Rivera, Ruby Bello, Elena Rodríguez-Aguado, Mohammed R. Elshaer, Rebecca L. Wodzinski, Svetlana Bashkova
      First page: 27
      Abstract: Activated carbons prepared from cashew nut shells and modified by grafting polyethylenimine onto the surface were tested for removal of Cr (VI). The removal efficiency of carbons without and with polyethylenimine decreased with an increase in pH, with maximum efficiency found at pH 2. The average maximum adsorption capacities of carbons were calculated to be 340 ± 20 mg/g and 320 ± 20 mg/g for unmodified and modified carbons, respectively. Surface characterization of carbons revealed that C–O functionalities are actively involved in both polyethylenimine grafting and Cr (VI) removal. Moreover, lactone groups and amides, formed by polyethylenimine grafting, seemingly undergo acid hydrolysis with formation of phenol and carboxylic groups. Considering that Cr (III) is the only form of chromium found on the surface of both carbons, the reduction mechanism is deduced as the predominant one. Here Cr (VI), majorly present as HCrO4¯, is attracted to the positively charged carbon surface, reduced to Cr (III) by phenol groups, and adsorbed inside the pores. The mechanism of Cr (VI) removal appears to be similar for unmodified and modified carbons, where the smaller adsorption capacity of the latter one can be related to steric hindrance and pore inaccessibility.
      Citation: C
      PubDate: 2021-02-27
      DOI: 10.3390/c7010027
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 28: Impact of Nitrogen, Boron and Phosphorus Impurities
           on the Electronic Structure of Diamond Probed by X-ray Spectroscopies

    • Authors: Sneha Choudhury, Ronny Golnak, Christian Schulz, Klaus Lieutenant, Nicolas Tranchant, Jean-Charles Arnault, Marie-Amandine Pinault-Thaury, François Jomard, Peter Knittel, Tristan Petit
      First page: 28
      Abstract: Doping diamond with boron, nitrogen or phosphorus enables a fine tuning of its electronic properties, which is particularly relevant for applications involving electron emission. However, the chemical nature of the doping sites and its correlation with electron emission properties remain to be clarified. In this work, we applied soft X-ray spectroscopy techniques to probe occupied and unoccupied electronic states in undoped, boron-, phosphorus- and nitrogen-containing single crystal diamonds. X-ray absorption, X-ray emission and X-ray photoemission spectroscopies, performed at the carbon K-edge, provide a full picture of new electronic states created by impurities in diamond. The different probing depths of fluorescence- and electron-based detection techniques enable a comparison between surface and bulk contributions.
      Citation: C
      PubDate: 2021-03-09
      DOI: 10.3390/c7010028
      Issue No: Vol. 7, No. 1 (2021)
       
  • C, Vol. 7, Pages 29: Carbide-Derived Carbons: WAXS and Raman Spectra for
           Detailed Structural Analysis

    • Authors: Riinu Härmas, Rasmus Palm, Heisi Kurig, Laura Puusepp, Torben Pfaff, Tavo Romann, Jaan Aruväli, Indrek Tallo, Thomas Thomberg, Alar Jänes, Enn Lust
      First page: 29
      Abstract: Quick characterization methods to determine the structure of carbon materials are sought after for a wide array of technical applications. In this study we present the combined analysis of the structure of carbide-derived carbons (CDCs) with Raman spectroscopy and wide-angle X-ray scattering (WAXS) methods. We present the optimal deconvolution method to be used for the detailed analysis of Raman spectroscopy data of CDCs and comparison to corresponding WAXS results is made. For a broad set of CDCs both WAXS and Raman spectroscopy data showed that the average graphene layer extent increases with synthesis temperature of CDC, while the coherent domain lengths obtained from Raman spectroscopy higher by an average of 4.4 nm. In addition, the presence of correlations between the parameters (D-band width and the parameter A∑D/A∑G) from Raman spectroscopy and the synthesis temperature are established. Based on the WAXS and Raman spectra data analysis the strong influence of the precursor carbide structure on the graphitization pathway is shown.
      Citation: C
      PubDate: 2021-03-20
      DOI: 10.3390/c7010029
      Issue No: Vol. 7, No. 1 (2021)
       
 
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