Subjects -> CHEMISTRY (Total: 987 journals)
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    - CHEMISTRY (716 journals)
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    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (716 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 20)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 34)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 4)
ACS Catalysis     Hybrid Journal   (Followers: 62)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 24)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 30)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 48)
ACS Nano     Hybrid Journal   (Followers: 421)
ACS Photonics     Hybrid Journal   (Followers: 17)
ACS Symposium Series     Full-text available via subscription   (Followers: 3)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Chemica Iasi     Open Access   (Followers: 8)
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: 9)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 11)
Adsorption Science & Technology     Open Access   (Followers: 8)
Advanced Electronic Materials     Hybrid Journal   (Followers: 3)
Advanced Functional Materials     Hybrid Journal   (Followers: 72)
Advanced Science Focus     Free   (Followers: 6)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 1)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 95)
Advances in Chemical Science     Open Access   (Followers: 39)
Advances in Chemistry     Open Access   (Followers: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 22)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 10)
Advances in Enzyme Research     Open Access   (Followers: 12)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 32)
Advances in Nanoparticles     Open Access   (Followers: 19)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Polymer Science     Hybrid Journal   (Followers: 50)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7)
Advances in Science and Technology     Full-text available via subscription   (Followers: 15)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 4)
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: 69)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 37)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 16)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 39)
Angewandte Chemie     Hybrid Journal   (Followers: 208)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 323)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
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: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 11)
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: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 8)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 450)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 6)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 4)
Biomacromolecules     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 202)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 89)
Bioorganic Chemistry     Hybrid Journal   (Followers: 9)
Biopolymers     Hybrid Journal   (Followers: 18)
Biosensors     Open Access   (Followers: 3)
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: 4)
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 Research     Hybrid Journal   (Followers: 25)
Carbon     Hybrid Journal   (Followers: 76)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 11)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 15)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 3)
ChemCatChem     Hybrid Journal   (Followers: 9)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 82)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Letters : X     Open Access   (Followers: 2)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 24)
Chemical Reviews     Hybrid Journal   (Followers: 248)
Chemical Science     Open Access   (Followers: 36)
Chemical Science International Journal     Open Access   (Followers: 1)
Chemical Technology     Open Access   (Followers: 57)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
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: 209)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 19)
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: 6)
Chemistry Education Review     Open Access   (Followers: 3)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 48)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 311)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
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: 15)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access   (Followers: 1)
ChemSystemsChem     Hybrid Journal   (Followers: 1)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 12)
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: 23)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Communications Materials     Open Access   (Followers: 3)
Composite Interfaces     Hybrid Journal   (Followers: 10)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 2)

        1 2 3 4 | Last

Similar Journals
Journal Cover
Colloid and Polymer Science
Journal Prestige (SJR): 0.597
Citation Impact (citeScore): 2
Number of Followers: 12  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0303-402X - ISSN (Online) 1435-1536
Published by Springer-Verlag Homepage  [2626 journals]
  • Schulze-Hardy rule revisited
    • Abstract: Abstract The classical Schulze-Hardy rule suggests that the critical coagulation concentration (CCC) decreases as the inverse sixth power of the counterion valence. While this dependence can be derived from the theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO), this derivation relies on unrealistic assumptions. In particular, one cannot assume that the electrolytes are symmetric, since one normally works with the better soluble asymmetric electrolytes. For such electrolytes, however, it is essential to distinguish between multivalent counterions and coions. For multivalent counterions, one must consider their strong tendency towards adsorption to the oppositely charged substrates, which leads to low charge densities. In this situation, the CCC increases with the surface charge density, inducing the strong decrease of the CCC with valence. For multivalent coions, the substrates are typically highly charged. In this case, the CCC decreases with increasing ionic valence and is in fact inversely proportional to the valence. This dependence is referred to as the inverse Schulze-Hardy rule.
      PubDate: 2020-08-01
       
  • Thermal conductivity of emulsion with anisotropic microstructure induced
           by external field
    • Abstract: The structure formation influence on various macroscopic properties of disperse systems is poorly investigated in respect to emulsion systems. The present work deals with the experimental and theoretical study of the heat transfer in emulsions whose dispersed phase droplets are arranged into chain-like structures under the action of external force field. The studied emulsions are of water-in-oil and oil-in-water types; they are based on ferrofluid and contain dispersed phase droplets in a size range of the order of several tens of micrometers. It is demonstrated that the emulsion thermal conductivity grows notably under the effect of external magnetic field parallel to the heat flux and provoking structure formation. It is revealed that the maximal response of thermal conductivity on the magnetic field action takes place at the dispersed phase volume fraction of about 20–30%. The structure formation in magnetic field has been simulated, and the magnetic interactions of emulsion droplets with each other and with the sample boundaries have been considered and discussed. The macroscopic thermal conductivity of structured emulsions has been numerically calculated and compared with experimental data. The obtained results may be of interest in the development of potential applications of controlling the properties of colloids by magnetic field. Graphical abstract
      PubDate: 2020-08-01
       
  • All-dry patterning method to fabricate hydrophilic/hydrophobic surface for
           fog harvesting
    • Abstract: Abstract Inspired by natural creatures that live in the arid climate, fog harvesting can be an efficient approach to overcome freshwater scarcity. Fog harvesting ability of the creatures is mainly based on wettability differences of their surfaces. In this study, inspired by creatures that have hydrophilic regions surrounded by hydrophobic areas, a novel all-dry patterning method was applied to fabricate hydrophilic/hydrophobic patterned surfaces for fog harvesting. For this purpose, patterned surfaces were produced using plasma-enhanced chemical vapor deposition (PECVD) method with the help of a commercial magnet and iron powders. The idea behind the use of the magnetic field during PECVD deposition is to hold light iron particles on the substrate under the vacuum environment for masking substrate surface. For the first time, the magnetic field was used to fabricate patterned surfaces in vapor-phase polymerization. Ordinary glass slides were successfully transformed into hydrophilic/hydrophobic patterned glasses. The obtained results showed that the combination of hydrophobic and hydrophilic regions improved the fog harvesting performance.
      PubDate: 2020-08-01
       
  • Finite ion size effect on the stability ratio of colloidal dispersions
    • Abstract: An algorithm is presented for calculating the stability ratio of a dispersion of spherical colloidal particles on the basis of the Derjaguin–Landau–Verwey–Overbeek theory. The finite ion size effect is taken into account by using the approximate form of ionic activity coefficients given by Carnahan and Starling. A simple approximate analytic expression for the stability ratio without involving numerical integration is also derived. Graphical abstract Finite ion size effect on the stability ratio of colloidal dispersions.
      PubDate: 2020-08-01
       
  • Controlled grafting modification of starch and UCST-type thermosensitive
           behavior in water
    • Abstract: Abstract A controlled grafting modification starch exhibited tunable phase transition temperature in aqueous solution was prepared via reversible addition–fragmentation chain transfer (RAFT) polymerization and esterification reaction under mild condition. P(AM/AN) copolymer was grafted onto the starch backbone and endowed the grafted copolymer thermosensitivity. The molecular structure and composition of P(AM/AN) copolymers were characterized by gel permeation chromatography (GPC), FTIR, and NMR, indicating a structurally controllable side chain of the grafted copolymer. Results of X-ray diffraction (XRD) demonstrate that the crystallinity of grafted copolymer decreases compared with starch due to side chains destruct the structural regularity of starch. Scanning electron microscopy (SEM) images show that grafted copolymer displays a rough, multilayer, and irregular morphology. Dynamic light scattering (DLS) and UV tests indicate that the grafted copolymer forms aggregates in aqueous solution and the UCST of the grafted copolymer is dependent on percent grafting (PG) and molecular interactions of side chains.
      PubDate: 2020-08-01
       
  • Colloidal stability and rheological properties of gold
           nanoparticle–loaded polymeric hydrogels: impact of nanoparticle’s
           shape, surface modification, and concentration
    • Abstract: Abstract Gold nanorods (GNR) and gold nanospheres (GNS) of different surface charges; neutral -poly ethylene glycol (PEG), negatively charged poly acrylic acid (PAA), and positively charged poly allyl amine hydrochloride (PAH), were synthesized and characterized, and their colloidal stability was investigated using UV-Vis absorption spectra and zeta potential measurements. Gold nanoparticles (GNP) were loaded at different concentrations (from 1.0 to 6.0 nM) into two hydrogels prepared in water; 18% w/v Poloxamer 407 and 1.5% w/v hydroxypropyl methylcellulose (HPMC). The GNP hydrogels were characterized in terms of GNP colloidal stability, and the rheological properties of the GNP hydrogels. GNP loaded into HPMC hydrogel demonstrated poor stability and exhibited separation into two layers. On the contrary, colloidal stability of the GNP was preserved upon loading into Poloxamer 407 hydrogel. The rheology study demonstrates that Poloxamer 407 hydrogel was able to accommodate GNR or GNS at concentrations lower than 6.0 nM with no apparent change in the measured rheology parameters. PAH-coated GNP caused the largest decrease in the low shear rate viscosity values. The elastic modulus was higher than the viscous modulus at the entire concentration range and the values of the phase shift angle did not exceed 10 degrees indicating prevail elastic property. As a conclusion, Poloxamer 407 hydrogel is a good candidate as a topical vehicle for both GNR and GNS at concentrations lower than 6.0 nM.
      PubDate: 2020-08-01
       
  • Influence of surface roughness on contact angle hysteresis and spreading
           work
    • Abstract: Abstract Surface roughness is an important factor that affects dynamic wetting behavior, which can improve the surface hydrophobicity, so it is of great significance to obtain a better understanding of roughness effect from both theoretical and practical perspectives. In this paper, we studied the influence of macro-size surface roughness on contact angle hysteresis and spreading work and analyzed the relationship between contact angle hysteresis and spreading work. Results showed that as the surface roughness increased, both the advancing contact angle and the receding contact angle continued to increase until their maximum values were reached, and then started to decrease within the range of surface roughness studied, while the contact angle hysteresis presented the opposite trend. In addition, with the increase of surface roughness the spreading work initially increased to a certain maximum value, then continuously decreased to the minimum value, and then began to increase within the range of the surface roughness studied. These trends could be attributed to the surface wetting state (Wenzel state, Cassie state, and transition state) changing with the change of surface roughness. These findings can provide guidance for the preparation of wetted surfaces with specific functions, especially when it is required to change the wettability without changing the surface chemical properties.
      PubDate: 2020-08-01
       
  • Facile production of cellulosic organic solutions and organogels from
           ionic liquid media
    • Abstract: In this study, we investigate what types of cellulosic materials are formed by soaking the cellulose/ionic liquid (1-butyl-3-methylimidazolium chloride, BMIMCl) solutions in various organic liquids. When the 5-wt% cellulose/BMIMCl solutions were soaked in organic liquids with high and moderate polarities (relative permittivities), the corresponding cellulosic solutions and gels were produced, respectively. On the other hand, soaking the cellulose/BMIMCl solutions in lower polar liquids resulted in aggregation of cellulose in the mixtures. As the gels with high boiling point media were stable, they were characterized by viscoelastic and compression measurements. Contents of organic media and BMIMCl in the gels were changed depending on the polarities, which affected the mechanical properties under compression mode. Furthermore, processes for production of the solution, gel, and aggregate were proposed. Graphical abstract Facile production of cellulosic organic solutions and organogels from ionic liquid media
      PubDate: 2020-08-01
       
  • Preparation and application performance of lignin-polyurea composite
           microcapsule with controlled release of avermectin
    • Abstract: Abstract Pickering emulsion stabilized by lignin/sodium dodecyl sulfate composite nanoparticles (LSNP) was used as template to prepare the avermectin @ lignin/polyurea composite microcapsules (AVM@LPMC) through ion cross-linking and interfacial polymerization. The inner wall of the microcapsules is a firm and compact polyurea layer, and the outer wall is a loose lignin layer. The effects of stirring speed, dosage of sodium dodecyl sulfate (SDS), and pH value in aqueous phase on the formation of microcapsules were systematically studied. The results showed that the optimal stirring speed was 200 rpm, and the optimal dosage ratio in water phase was HCl (mmol):SDS (mmol):lignin AL (g) = 0.375:1.25:1 in fixed oil-water ratio (1:9) and oil phase composition. In this way, the encapsulation efficiency of microcapsules could reach up to 85.4%, while it would slightly decrease with the increase of lignin content in the wall materials. The polyurea layer played a key role in supporting the spherical structure of the capsule wall and delaying the release of avermectin, while the loose lignin layer contributed less to the slow release performance of microcapsule. By changing the amount of lignin, the polyurea-layer thickness could be regulated to adjust the release rate of microcapsule. Remarkably, a small amount of lignin introduced in the wall material could significantly improve the anti-photolysis performance of avermectin in microcapsules.
      PubDate: 2020-08-01
       
  • Controlled fabrication of polymer nanofibers via conventional free radical
           polymerization using diurea xerogel fibers as the templates
    • Abstract: Polymer nanofibers with smooth surface were fabricated via conventional free radical polymerization of diurea type supramolecular gel fibers in cyclohexane. As the solvent polarity by using toluene increased, the product yield and fiber size increased, while the fibers changed from smooth to rough, together with more and more free particles. In the presence of polar methacrylic acid, both rough fibers and free particles were obtained when polymerized in cyclohexane. When nonpolar 2-(perfluoro-3-methylbutyl)ethyl acrylate (R-3420) was used, only polymer fibers with very smooth surface were formed. The morphologies of fluoropolymer samples changed from fibers to particles, while the fiber surface became rougher and rougher, as more and more ethanol was used. The hydrophobic fluoropolymer sample could extract toluene from water-toluene two-phase system. Compared with granular fluoropolymer samples, fibrous fluoropolymer samples displayed higher specific surface area and higher swelling ratio in toluene, and required a shorter time for toluene to flow through them. Graphical abstract
      PubDate: 2020-08-01
       
  • A DSC and XPS characterization of core–shell morphology of block
           copolymer nanoparticles
    • Abstract: Abstract Self-assembly of amphiphilic block copolymer chains is known to produce core–shell nanoparticles, but imaging techniques have generally failed to provide clear evidence about the multiphase structure. We report herein the advantages and limitations of modulated temperature differential scanning calorimetry (MDSC) and X-ray photoelectron spectroscopy (XPS) for the morphology study of spherical poly(hydroxyethyl acrylate)-b-polystyrene diblock copolymer nanoparticles with an intensity-average diameter of 40 nm. Using lyophilized particles, MDSC is more informative than XPS since it allows the three morphological features of composite latex particles to be distinguished: polystyrene core, poly(hydroxyethyl acrylate) shell, and interface. In MDSC, phase separation is evidenced by two distinct increments of heat capacity (ΔCp) in the glass transition regions of the two blocks. By measuring ΔCp values, an interface weight fraction of 70% is measured that gradually decreases to 50% with annealing time (150 °C, 2 h), indicating a higher extent of phase separation.
      PubDate: 2020-08-01
       
  • The aggregation behavior of fluorinated surfactant in an ionic liquid
    • Abstract: Although ionic liquids have been studied as self-assembly media, the aggregation of fluorinated surfactants in ionic liquids has not been fully understood. In this work, the aggregation behavior of the fluorinated surfactant, N-ethylperfluorooctane sulfonamide (N-EtFOSA), in the aprotic ionic liquid, 1-ethyl-3-methylimidazolium ethylsulfate ([C2mim][EtSO4]), was studied using surface tension, 19F-NMR, dynamic light scattering (DLS), and cryo transmission electron microscopy (cryo-TEM). The surface properties and thermodynamic parameters were calculated based on the results of surface tension measurements. It was found that the fluorinated surfactant exhibits a considerable surface activity in aprotic ionic liquids, and its critical micelle concentration (cmc) increases with increasing temperature. In addition, the surface properties indicate that solvophobic interactions are the main driving force for micelle formation. The thermodynamic parameters for micelle formation derived from the temperature dependence of the cmc revealed that micelle formation is an enthalpy-driven process. DLS and cryo-TEM results indicated the presence of nanoscale micelles in the N-EtFOSA + [C2mim][EtSO4] system. The results of this work imply that this fluorinated surfactant exhibits a more pronounced surface activity than conventional hydrocarbon surfactants in [C2mim][EtSO4]. Graphical abstract The self-assembly of fluorinated surfactants in aprotic ionic liquids
      PubDate: 2020-08-01
       
  • Analysis of granulation mechanism in a high-shear wet granulation method
           using near-infrared spectroscopy and stirring power consumption
    • Abstract: Abstract The dynamic granulation process of high-speed shear wet granulation (HSWG) was measured by in-line near-infrared spectroscopy (NIRS) and agitation power consumption (APC) methods. Molecular interactions between powder particles and the binding liquid were analyzed based on both NIRS and APC data by multivariable regression analysis. The granulated sample used glass beads (d50 = 46 μm) with or without hydroxypropyl cellulose, and the binder solution used purified water. The HSWG granulator (2-L volume) with APC device and NIRS was used, and the agitator was rotated at 600 min−1 and the chopper at 2000 min−1 with glass beads to be granulated being 920 g (0.6 L), and a total of 360 mL of purified water was added at 10 mL/min. In order to establish calibration models to predict APC and amount of binding water of the granular formulations, NIRS spectra of the granular samples were recorded every 10 s for 40 min. The calibration models to predict moisture content and APC were constructed based on the corrected NIRS spectral data by partial least-squares regression (PLSR) analysis. The relationships between actual and predicted values for moisture content and APC produced a straight line, respectively. The regression vector (RV) of the PLS model to predict the water content showed the presence of free water between the bead powder particles. On the other hand, the RV for the APC showed the presence of bound water between the particles.
      PubDate: 2020-08-01
       
  • Redox-responsive AIE micelles for intracellular paclitaxel delivery
    • Abstract: Abstract Compared with conventional drug nanocarriers, multifunctional drug delivery systems exhibited characteristic advantages. In this study, we developed a multifunctional drug delivery system possessing stimuli-responsive drug release and cellular imaging. Amphiphilic polymers, methoxypolyethylene glycol-cystamine-tetraphenylethene (mPEG1k-SS-TPE), were synthesized by combining methoxypolyethylene glycol (mPEG1k) and tetraphenylethene (TPE) using reduction-sensitive disulfide bonds that can be disconnected by high level of inherent glutathione (GSH). Size distribution and morphology of mPEG1k-SS-TPE micelles were evaluated. Meanwhile, the reduction-sensitivity of mPEG1k-SS-TPE micelles was surveyed compared with that of mPEG1k-TPE micelles. Nile Red was encapsulated into mPEG1k-SS-TPE micelles to visually observe intracellular drug delivery against SW480 cells. Paclitaxel (PTX) was chosen to be loaded into micelles to evaluate the cytotoxicity against HCT116, HT-29, and SW480. Graphical Abstract
      PubDate: 2020-08-01
       
  • Encapsulation of caffeine in polysaccharide oil-core nanocapsules
    • Abstract: Abstract Nanoemulsion droplets stabilized with a polysaccharide multilayer film were used as carriers for caffeine. Multilayered shells were formed through a subsequent layer-by-layer adsorption of oppositely charged chitosan and alginate (sodium salt) onto emulsion droplets or oil-core nanocapsules at low ionic strength. The hydrophilic positively charged molecules of the drug were impregnated into the film after each alginate layer. The experimental results showed dependence of the encapsulation efficiency of caffeine on the number of the adsorbed polymer layers and on the properties of chitosan used for formation of the film (molecular weight and degree of acetylation). Despite the low encapsulation efficiency of the drug into the capsules (~ 40%) compared with other encapsulation systems, the amount loaded into the film was high enough and pharmacological doses were achieved with very small volumes of the dispersion. Encapsulation of caffeine in polysaccharide multilayered oil-core nanocapsules
      PubDate: 2020-08-01
       
  • Synthesis and property of polyurethane elastomer for biomedical
           applications based on nonaromatic isocyanates, polyesters, and ethylene
           glycol
    • Abstract: Abstract Polyurethane (PU) elastomers were synthesized by the reaction of HDI or IPDI diisocyanates and poly(ε-caprolactone) (PCL or poly(ethylene adipate) (PA) diols and ethylene glycol as a polymer chain extender. IR, 1H, and 13C NMR spectroscopy and X-ray analysis were used for the structural analysis of the formed films. The molecular weight distribution was examined by GPC chromatography. Based on the measured contact angles, free surface energy parameters were calculated. The obtained results were analyzed for the possible use of these polyurethanes as biomaterials. The most promising in this respect was PU-3, which was synthesized from IPDI and PCL. This was due to its high molecular weight of approximately 90,000, the presence of a crystalline phase, and the relatively high hydrophobicity, with a SEP value below 25 mJ/m2. These films showed a good resistance to hydrolysis during incubation in Baxter physiological saline during 6 weeks. Both Gram-positive (Bacillus sp.) and Gram-negative (Pseudomonas sp.) types of bacterial strains were used to test the biodegradation property. Synthesized PUs are biodegradable and showed moderate or even mild cytotoxicity against human normal fibroblasts (BJ) and immortalized keratinocytes (HaCaT), estimated with direct contact assay. The most biocompatible was PU-3 film, which revealed rather mild reactivity against both cell lines, and the least was PU-2 film, synthesized from HDI and PA (severe toxicity for HaCaTs).
      PubDate: 2020-08-01
       
  • High performance of molecularly imprinted polymer for the selective
           adsorption of erythromycin in water
    • Abstract: Abstract In this paper, a high adsorption performance of erythromycin molecularly imprinted polymer (ERY@MIP) was prepared by bulk polymerization. Scanning electron microscope, thermogravimetric analysis, and Fourier transform infrared spectroscopy were used to characterize the morphology and structure of imprinted polymers. The maximum adsorption capacity of ERY@MIP for ERY was 1048.8 mg g−1; it also has good selectivity compare with other antibiotics. Further, the thermodynamic and kinetic analysis shows that the experiment results accord with the Langmuir model and the quasi-second-order kinetic model, respectively.
      PubDate: 2020-08-01
       
  • Physical and barrier properties of chemically modified pectin with
           polycaprolactone through an environmentally friendly process
    • Abstract: The paper reports the preparation of a novel material composed of pectin chemically modified with polycaprolactone (PCL). PCL was firstly functionalized through radical grafting of maleic anhydride and glycidyl methacrylate in the molten state and then used as grafting agent onto pectins from apple, using a solvent free process. The obtained material was submitted to melt process on laboratory scale and films obtained. Structural, thermal, mechanical, and barrier properties to water vapor were evaluated and compared with pure pectin and modified PCL’s films. The used strategy allowed to overcome the processability problems of a natural polymer, like pectin, that undergoes degradation with the temperature and is not processable without additives and plasticizers. The proposed green process represents a good opportunity to manufacture waste materials from fruits to obtain flexible and fully biodegradable polymers for food packaging applications, as interesting alternative to not biodegradable traditional thermoplastics. Graphical abstract
      PubDate: 2020-07-11
       
  • Influence of ionic strength on gel-like Pickering emulsions stabilized by
           self-assembled colloidal nanoparticles containing lysozyme
    • Abstract: Introducing lysozyme (Lys) to dopamine-modified poly (γ-glutamic acid) (PGA-DA), the self-assembled colloidal nanoparticles (Lys/PGA-DA) were obtained through the electrostatic, hydrogen bonding and hydrophobic interactions. After mixing vigorously colloidal nanoparticles and white oil, o/w gel-like emulsion formed. The influences of ionic strength on the properties and emulsifying performances of colloidal nanoparticles and the activity of Lys in emulsions were investigated in detail. Scanning electron microscopy (SEM) characterization and rheological measurements demonstrated that emulsifying properties of colloidal nanoparticles were significantly improved with increasing salt concentration. Moreover, fluorescence and circular dichroism (CD) measurements showed that the addition of salt might induce conformational changes of Lys in colloidal nanoparticles resulting in a more ordered secondary structure, thereby leading to an increase in enzyme activity. In vitro cytotoxicity of emulsions revealed that emulsions showed a low cytotoxicity and a high bioactivity. All results verified that the obtained emulsion could have potential application in food, pharmaceutical, and cosmetic fields. Graphical abstract
      PubDate: 2020-07-10
       
  • Enzymatic transesterification of urethane-bond containing ester
    • Abstract: Here we demonstrate the feasibility and successful application of enzymes in polyurethane network synthesis as well as occurring hurdles that have to be addressed when using urethanes synthesis substrates. The enzymatic transesterification of an urethane-bond containing monofunctional ester and a model alcohol carbitol using lipases is discussed. The reaction is optimized in terms of transesterification time and temperature, the reaction solvent, the possibility of a cosolvent and the alcohol amount, the used transesterification environment, and the biocatalyst. Enzymatic cross-linking of polyurethanes can open up a pool of new possibilities for cross-linking and related polyurethane network properties due to the enzymes high enantio-, stereo-, and regioselectivity and broad substrate spectrum. Graphical abstract
      PubDate: 2020-07-10
       
 
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