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  Subjects -> CHEMISTRY (Total: 931 journals)
    - ANALYTICAL CHEMISTRY (58 journals)
    - CHEMISTRY (663 journals)
    - CRYSTALLOGRAPHY (21 journals)
    - ELECTROCHEMISTRY (27 journals)
    - INORGANIC CHEMISTRY (43 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (663 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 16)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 31)
ACS Applied Polymer Materials     Hybrid Journal  
ACS Catalysis     Hybrid Journal   (Followers: 55)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 22)
ACS Combinatorial Science     Hybrid Journal   (Followers: 21)
ACS Macro Letters     Hybrid Journal   (Followers: 29)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 46)
ACS Nano     Hybrid Journal   (Followers: 380)
ACS Photonics     Hybrid Journal   (Followers: 15)
ACS Symposium Series     Full-text available via subscription   (Followers: 1)
ACS Synthetic Biology     Hybrid Journal   (Followers: 25)
Acta Chemica Iasi     Open Access   (Followers: 6)
Acta Chimica Slovaca     Open Access   (Followers: 2)
Acta Chimica Slovenica     Open Access   (Followers: 1)
Acta Chromatographica     Full-text available via subscription   (Followers: 8)
Acta Facultatis Medicae Naissensis     Open Access  
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 7)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 8)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 9)
Adsorption Science & Technology     Open Access   (Followers: 7)
Advanced Functional Materials     Hybrid Journal   (Followers: 65)
Advanced Science Focus     Free   (Followers: 5)
Advances in Chemical Engineering and Science     Open Access   (Followers: 88)
Advances in Chemistry     Open Access   (Followers: 29)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 8)
Advances in Enzyme Research     Open Access   (Followers: 11)
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: 29)
Advances in Nanoparticles     Open Access   (Followers: 19)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Polymer Science     Hybrid Journal   (Followers: 49)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Science and Technology     Full-text available via subscription   (Followers: 13)
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: 8)
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: 3)
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: 22)
American Journal of Chemistry     Open Access   (Followers: 35)
American Journal of Plant Physiology     Open Access   (Followers: 14)
American Mineralogist     Hybrid Journal   (Followers: 14)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 193)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 290)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 4)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 4)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
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: 9)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Atomization and Sprays     Full-text available via subscription   (Followers: 5)
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: 405)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 7)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 11)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 2)
Biomacromolecules     Hybrid Journal   (Followers: 25)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 10)
Biomedical Chromatography     Hybrid Journal   (Followers: 7)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 186)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 91)
Bioorganic Chemistry     Hybrid Journal   (Followers: 10)
Biopolymers     Hybrid Journal   (Followers: 17)
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: 25)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 3)
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: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 24)
Carbon     Hybrid Journal   (Followers: 72)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 10)
Catalysis Science and Technology     Hybrid Journal   (Followers: 10)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 14)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 76)
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: 234)
Chemical Science     Open Access   (Followers: 33)
Chemical Technology     Open Access   (Followers: 49)
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: 8)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 32)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 192)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 17)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 22)
Chemistry Central Journal     Open Access   (Followers: 4)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry in Education     Open Access   (Followers: 9)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 46)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 283)
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)
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
ChemTexts     Hybrid Journal  
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)
Clay Minerals     Hybrid Journal   (Followers: 10)
Cogent Chemistry     Open Access   (Followers: 2)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 11)
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)
Communications Chemistry     Open Access   (Followers: 2)
Composite Interfaces     Hybrid Journal   (Followers: 8)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 1)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 2)
Computational and Theoretical Chemistry     Hybrid Journal   (Followers: 9)
Computational Biology and Chemistry     Hybrid Journal   (Followers: 13)
Computational Chemistry     Open Access   (Followers: 3)
Computers & Chemical Engineering     Hybrid Journal   (Followers: 10)
Coordination Chemistry Reviews     Full-text available via subscription   (Followers: 4)
Copernican Letters     Open Access   (Followers: 1)
Corrosion Series     Full-text available via subscription   (Followers: 7)
Critical Reviews in Biochemistry and Molecular Biology     Hybrid Journal   (Followers: 8)
Croatica Chemica Acta     Open Access  
Crystal Structure Theory and Applications     Open Access   (Followers: 4)
CrystEngComm     Full-text available via subscription   (Followers: 13)
Current Catalysis     Hybrid Journal   (Followers: 2)
Current Chromatography     Hybrid Journal  
Current Green Chemistry     Hybrid Journal   (Followers: 2)
Current Metabolomics     Hybrid Journal   (Followers: 6)
Current Microwave Chemistry     Hybrid Journal  
Current Opinion in Colloid & Interface Science     Hybrid Journal   (Followers: 10)

        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: 11  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0303-402X - ISSN (Online) 1435-1536
Published by Springer-Verlag Homepage  [2574 journals]
  • Controlled synthesis and self-assembly of amphiphilic copolymers based on
           2,2,3,3,4,4,5,5-octafluoropentyl acrylate and acrylic acid
    • Abstract: The reversible addition–fragmentation chain transfer (RAFT) polymerization of 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (OFPA) in the presence of different concentrations of S,S-dibenzyl carbonotrithioate as chain transfer agent (CTA) was investigated. The estimate of Ctr was defined using the size-exclusion chromatography measurements. Copolymers of acrylic acid and OFPA with different microstructure were synthesized by three methods: block copolymerization, copolymerization of acrylic acid and OFPA, and chemical modification of copolymer of tert-butyl acrylate and OFPA. Copolymerization of abovementioned monomer pairs was studied. The reactivity ratios were calculated by using the Fineman–Ross and Kelen–Tudos models, as well as the method of least squares. Aggregation behavior of the obtained amphiphilic copolymers at the air/water interface was defined by the Langmuir monolayer technique. Monomolecular films of amphiphilic copolymers were studied using atomic force microscopy. The effect of the chain microstructure, the acrylic acid content in the copolymer, and subphase pH on the isotherm curves were shown. Graphical abstract
      PubDate: 2019-12-01
       
  • Effect of chain length and counter-ion on interaction study of mixed
           micellar system of isoquinoline-based surface active ionic liquid and
           cationic surfactants in aqueous medium
    • Abstract: In the present study, we have investigated the effect of nature of surfactant, chain length and counter-ion on the mixed micellization behaviour ofvarious cationic surfactants, tetradecyltrimethylammonium bromide (TTAB), dodecyltrimethylammonium chloride (DTAC) and cationic gemini surfactant, bis(tetradecyldimethylammonium)hexane dibromide(C14-6-C14,2Br) with surface active ionic liquid (SAIL) tetradecylisoquinolinium bromide [C14iQuin][Br]. The interactions and mixed micellar behaviour of cationic surfactants and SAIL in aqueous medium have been studied by employing conductometry measurements and 1H NMR technique. The critical micelle concentration (cmc) and various thermodynamic parameters like standard Gibbs free energy of micellization (ΔGm0), change in standard enthalpy (ΔHm0) and entropy of micellization (ΔSm0) have been calculated from conductometry measurements. Mixed micellar parameters such as ideal cmc (cmc*), micellar mole fraction (X1m), micellar interaction parameter (βm) and activity coefficients, (f1 and f2) have been evaluated by applying Clint, Rubingh and Motomura theoretical models. Synergistic and non-ideal interactions have been found between SAIL and surfactants. Graphical abstract
      PubDate: 2019-12-01
       
  • Superhydrophobic polymer composite coating on glass via spin coating
           technique
    • Abstract: Abstract In this work, a superhydrophobic coating on glass surface has been prepared by using polymethylmethacrylate, SiO2 nanoparticles, and hexadecyltrimethoxysilane via spin coating technique. Coating was characterized by using contact angle measurement technique, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Coating shows the superhydrophobic nature with water contact angle of 165 ± 5° and tilt angle of 7 ± 1°. Thermal, chemical, and mechanical stability of coating was also examined, and it is found excellent wetting stability of coating under harsh conditions. Droplet dynamics behavior of water droplets on coating was also studied and bouncing, pinning, and splashing of water droplets are observed at different impact velocities. Coating also exhibits the excellent self-cleaning nature. Prepared coating shows its several industrial applications.
      PubDate: 2019-12-01
       
  • Functionalized graphene nanoplatelets/modified polybutadiene hybrid
           composite
    • Abstract: Functionalized graphene nanoplatelets (FGNPs) were synthesized through oxidative chlorophosphorylation (OxCh) reaction of graphite and subsequent hydrolysis of obtained chlorophosphonated graphite. Then FGNPs were used as a nanoscale filler to fabricate FGNPs/modified polybutadiene (MPB) hybrid composite (FGNPs/MPB). Fourier-transform infrared spectroscopy found that FGNPs have phosphonate functional groups and FGNPs/MPB has phosphonate and phosphate functional groups. X-ray diffraction showed that the thickness of FGNPs is 13.53 nm and the number of their layers is equal to 40, which are less than graphite’s thickness (37.08) and layers (111). FGNPs show high conductivity and dielectric permittivity than graphite, while FGNPs/MPB has improved electric properties than MPB without filler. Thermal properties of FGNPs/MPB also improve due to the fact that FGNPs achieve a high degree of dispersion with less agglomeration. As observed in the scanning electron microscope images, FGNPs/MPB displays a two-phase morphology with an MPB continuous phase and a dispersed FGNPs phase. Graphical abstract
      PubDate: 2019-12-01
       
  • Association behavior and fluorescence quenching between cationic zinc
           porphyrin pendant groups on water-soluble polymers and anionic iron
           porphyrin guests
    • Abstract: Abstract An amphiphilic cationic tripyridiniumylporphyrin monomer, i.e., ZnTrMPyP, was synthesized and copolymerized with acrylamide in water and dimethyl sulfoxide, respectively, to prepare the water-soluble random copolymer P-D and microblock copolymer P-W. The association behavior and fluorescence quenching between the copolymers and tetra(p-sulfonato phenyl)porphyrin (Fe(III)TSPP(Cl)) were studied via absorption and emission spectra. The results showed that relatively discrete pendant groups of ZnTrMPyP within P-D could form a ground state complex with FeTSPP by electrostatic interactions, and both static and dynamic mechanisms were active in this quenching process. In contrast, the microblock porphyrin pendant groups within P-W interacted with FeTSPP as an entity, and static quenching was dominant in this process. Salt effects on the formation of the copolymers and FeTSPP complex were also investigated through the addition of KNO3, and the results showed that this association can be weakened by the electrostatic shielding effect, and the fluorescence quenching constant could be reduced.
      PubDate: 2019-11-16
       
  • Dimeric camptothecin-loaded mPEG-PCL nanoparticles with high drug loading
           and reduction-responsive drug release
    • Abstract: Abstract Camptothecin (CPT) is a potent and broad-spectrum anti-tumor drug, but its clinical application is limited due to its poor water solubility, toxicity, and low drug-loading potential. Different delivery protocols have been developed to optimize the therapeutic effects of CPT. In this study, CPT was modified into a dimer (CPT-Mal-CPT), in which two CPT molecules are connected by a reduction-responsive maleimide thioether bond. Moreover, biocompatible methoxy poly(ethylene glycol)-b-poly(ε-caprolactone) (mPEG–PCL)-loaded CPT-Mal-CPT nanoparticles were prepared to overcome the limits of CPT application. The power X-ray diffractometer (PXRD) results indicate low crystallinity and amorphous nature of CPT-Mal-CPT. The CPT-Mal-CPT-loaded micelles showed a drug-loading content of 9.6% and a drug-loading efficiency of 56%. In addition, dimeric CPT micelles showed reduction-responsive release under 10-mM dithiothreitol (DTT), while negligible CPT release was detected in the absence of DTT. MTT assay indicated that cytotoxicity of dimeric CPT micelle was similar to free CPT.
      PubDate: 2019-11-14
       
  • Controlled gel research: the effect of ethanol for delaying the
           polycondensation of tetraethyl orthosilicate-dimethyldiethoxysilane
    • Abstract: In this study, the effect of ethanol for delaying the polycondensation of silanol in the co-hydrolysis-condensation of tetraethyl orthosilicate-dimethyldiethoxysilane was first explored and demonstrated by varying the amount of ethanol under low-water content and acid-catalyzed. On the basis of this, the controllability of the sol-gel process is realized, and the calculation formula of the gel formation time is provided. The experiment shows that the storage gel time and the reaction gel time are extended from 75 h to at least 4584 h, or from 20 to 65 h with the increase of ethanol concentration, respectively. And we observed the microscopic process of solution-sol-gel transition by light transmission microscope. The sol-gel process established in this experiment gives a mechanism reference for future research. Graphical abstract Graphical abstract
      PubDate: 2019-11-09
       
  • The effects of grafting density and charge fraction on the properties of
           ring polyelectrolyte brushes: a molecular dynamics simulation study
    • Abstract: Using molecular dynamics simulations, the flexible ring polyelectrolyte chains tethered to a planar substrate and immersed in good solvents are investigated systematically. Two sets of simulations are performed to explore the effects of grafting density and charge fraction, respectively. Both the monovalent and trivalent counterions are considered. The height of the brush H follows a scaling relation with grafting density (~σgν) and charge fraction (~fν). The values of the exponents are different from those of the linear counterparts. Through a careful analysis on the distributions of monomers and counterions, pair correlation functions of monomer-monomer and monomer-counterion, as well as the fractions of trivalent counterions in four states, the equilibrium structures of the ring PE brushes are examined in detail. Furthermore, a brief comparison with the ‘equivalent’ linear brush is carried out. Also, our results can serve as a guide for improving the performance of ring polyelectrolyte brushes as unique surface modifiers. Graphical abstract .
      PubDate: 2019-11-09
       
  • Bio-based castor oil organogels and investigations on their anion-tuning
           properties
    • Abstract: We report here bio-based N-(2-hydroxyethyl) ricinoleic amide (NHRA) a derivative of castor oil, as a low molecular weight gelator showing good gelation in organic solvents. NHRA gelator molecules exhibited thermoreversible gelation in specific tested organic solvents such as aniline and 1,4 dioxane. The gelator molecules are self-assembled through intermolecular hydrogen bonding and van der Waals interactions which are the determining factors for the organogel formation as confirmed by FT-IR spectroscopy. Differential scanning calorimetry (DSC) measurements show the phase transition of gels from gel to solution state and strongly depend by varying the concentration of the gelator. The supramolecular aggregation of gelators in the gel state led to viscoelastic nature of the organogels and was studied by rheology. Morphological studies reveal the presence of lamellar fibrous-like structures, which are responsible for the molecules to aggregate into 3D network. The synthesized organogel acts as a host for anions that change the physical state from gel to sol by disruption of intermolecular hydrogen-bonding interactions. The propensity of the material to exhibit anion-responsive behavior is attributed to the presence of amide linkages, under which deprotonation of N–H fragments occur upon the addition of anions, as confirmed by 19F NMR and FT-IR spectroscopy. These results indicate that NHRA gelator can be prospective candidate for sensing applications Graphical abstract
      PubDate: 2019-11-07
       
  • Effect of hydrodynamic size on colloidal stability and lifetime of Mn-Zn
           magnetic fluids
    • Abstract: Abstract For transformer cooling applications, magnetic particles need to be dispersed in carrier fluids with high colloidal stability for a long period without significant degradation. However, stability of the suspension, especially the long term colloidal stability is a crucial factor for the applications in power transformers because aggregation of particles could cause clogging of micro-channels in transformers. In this article, we have reported effect of hydrodynamic size on the colloidal stability of Mn1-xZnxFe2O4 (MZ) nanoparticles (NPs)–based magnetic fluids. Lifetime of fluids has been determined from the increase in hydrodynamic size of magnetic NPs due to aggregation. Colloidal stability of fluids decreases with increase in the polydispersity of fluids caused by the enhanced dipole interactions between NPs resulting in the aggregation of NPs in chain-like structures. Abstract Graphic Chain formation in magnetic nanoparticles in fluids due to aging
      PubDate: 2019-11-05
       
  • Crosstalk between responsivities to various stimuli in multiresponsive
           polymers: change in polymer chain and external environment polarity as the
           key factor
    • Abstract: Abstract Multiresponsive polymers offer a wealth of possibilities to design switchable materials which respond to more than one stimulus. We describe first the response of polymers to a single external stimulus, namely to temperature, light, pH value, redox changes, and low molecular weight species, and discuss the influence of these stimuli on the polymer chain polarity. Then, we review multiresponsive homopolymers and statistical and block co-polymers. Finally, we discuss the similarity of multiresponsive synthetic polymers to biopolymers. As a conclusion, multiresponsiveness opens up a broad area for combining different properties in one system, enabling numerous possible applications.
      PubDate: 2019-10-31
       
  • Preparation and characterization of dithiocarbazate Schiff base–loaded
           poly(lactic acid) nanoparticles and analytical validation for drug
           quantification
    • Abstract: Dithiocarbazate Schiff bases have been reported as a class of compounds that exhibit a wide range of pharmacological activities against neglected diseases such as malaria, trypanosomiasis, and tuberculosis. This work reports the encapsulation of the 1-(S-benzyldithiocarbazate)-3-methyl-5-phenyl-pyrazole (DTC) into biodegradable polymeric nanoparticles (NPs) of poly(lactic acid) (PLA) aiming potential drug delivery application. The DTC-loaded PLA-NPs were prepared by the single-nanoemulsification method using the poly(vinyl alcohol) (PVA) as a surfactant. The nanostructured system was characterized mainly by dynamic light scattering (DLS), electrophoretic light scattering (ELS), and transmission electron microscopy (TEM). The NPs show good colloidal stability exhibiting mean hydrodynamic diameter 157 ± 5 nm and zeta potential − 36 ± 3 mV. The encapsulation efficiency and drug loading were 52 ± 14% and 4.8 ± 1.5%, respectively. The quantifications of DTC and residual PVA in the NPs were performed by UV-Vis absorption spectroscopy. The analytical methods were validated according to regulatory agencies. Both quantification analytical curves showed good precision, in repeatability (intra-day) and intermediate (inter-day), and also good accuracy with low values of detection and quantification. The new nanostructured system, DTC-loaded PLA-NPs, shows advantages to improve stability and to overcome water solubility problems of the dithiocarbazate Schiff bases aiming potential drug delivery applications. Graphical abstract .
      PubDate: 2019-10-31
       
  • Designing the poly[1,5-bis( N -pyrrolyl)pentane as a new horizon of
           polypyrrole paradigm with its structural and optical highlights
    • Abstract: Abstract Poly[1,5-bis(N-pyrrolyl)pentane] (PBNPP) has been designed as a new addition to the modified polypyrrole family. This study entails the introduction of a pentane spacer between two pyrrole moieties and subsequently their oxidative polymerization under ambient conditions. The newly designed monomer and its polymer were fully characterized by FT-IR. The structural and optical behaviors were comparatively explored with reference to polypyrrole (Ppy), which was again prepared under same conditions. SEM was employed to visualize the morphology of PBNPP and Ppy comparatively. The data demonstrated the morphology of the PBNPP as spherical beads with a greater extent of surface porosity compared to Ppy, which possesses a compact granular form. The structural parameters were explored by XRD, where both possess crystallites of smaller size. Thermal behaviors were analyzed by TGA and DSC, where the newly designed polymer showed greater thermal stability and more plasticizing trend as compared to Ppy. Optical and HOMO-LUMO attributes have been characterized using UV-Vis spectrophotometer and diffused reflectance spectroscopy (DRS). The PBNPP demonstrated greater molar absorption and lesser HOMO-LUMO gap as compared to Ppy. The PBNPP was proposed as a suitable candidate for photoconductivity compared with the Ppy. Thus, the polymer produced from the modified pyrrole is thermally more stable, has high plasticizing character, reflects greater optically sensitivity, and possesses ease of electronic transition compared to its counterpart.
      PubDate: 2019-10-30
       
  • Self-assembled vesicles of sodium oleate and chitosan quaternary ammonium
           salt in acidic or alkaline aqueous solutions
    • Abstract: Abstract Fatty acids are anionic surfactants under their deprotonated forms, which have biodegradability and biocompatibility. The fatty acid self-assembled aggregates exhibit many potential applications. Fatty acid vesicles are the most representative because of their special hollow double-layer membrane structure. However, their application is hindered by a poor stability against variations in pH, salt, and temperature. In this work, the anionic surfactant sodium oleate (SO) and the polycationic hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were mixed to form complex vesicles in a wider pH scale. The formation of vesicles was proved through TEM, fluorescence spectroscopy, and DLS; meanwhile, the intermolecular force–formed vesicles were verified through FT-IR and zeta potential analyses. The effect of electrolyte and temperature on the stability of the vesicle was also studied. The experimental results showed that with the aid of H-bonding and the electrostatic attraction separately, amphiphilic molecules were formed and they self-assembled into vesicles in both acidic and alkaline aqueous solutions. Graphical Abstract
      PubDate: 2019-10-29
       
  • Tunable viscosity modification with diluted particles: when particles
           decrease the viscosity of complex fluids
    • Abstract: While spherical particles are the most studied viscosity modifiers, they are well known only to increase viscosities, in particular at low concentrations of approx. 1%. Extended studies and theories on non-spherical particles in simple fluids find a more complicated behavior, but still a steady increase with increasing concentration. Involving platelets in combination with complex fluids—in our case, a bicontinuous microemulsion—displays an even more complex scenario that we analyze experimentally and theoretically as a function of platelet diameter using small angle neutron scattering, rheology, and the theory of the lubrication effect, to find the underlying concepts. The clay particles effectively form membranes in the medium that itself may have lamellar aligned domains and surfactant films in the case of the microemulsion. The two-stage structure of clay and surfactant membranes explains the findings using the theory of the lubrication effect. This confirms that layered domain structures serve for lowest viscosities. Starting from these findings and transferring the condition for low viscosities to other complex fluids, namely crude oils, even lowered viscosities with respect to the pure crude oil were observed. This strengthens our belief that also here layered domains are formed as well. This apparent contradiction of a viscosity reduction by solid particles could lead to a wider range of applications where low viscosities are desired. The same concepts of two-stage layered structures also explain the observed conditions for extremely enhanced viscosities at particle concentrations of 1% that may be interesting for the food industry. Graphical abstract
      PubDate: 2019-10-27
       
  • Interaction of ninhydrin with zinc(II) complex of tryptophan in the three
           dicationic gemini surfactants
    • Abstract: Abstract Present work concerns with the interaction of ninhydrin with zinc(II) complex of tryptophan ([Zn(II)-Trp]+) in the three dicationic gemini surfactant systems. To record critical micellar concentration (CMC) and absorbance, we have used Systronics conductivity meter and UV-visible spectrophotometer, respectively. Experiment opens up the fractional- and first-order paths in ninhydrin and complex, respectively. Gemini micellar medium is found more superior over aqueous medium. Rate constant (kψ) vs. [gemini] plot shows the unusual role of geminis on kψ. kψ increases with gemini concentration (at concentrations lower than the CMC, part I) and leveling-off regions obtain (concentration up to 400 × 10−5 mol dm−3, part II). Characteristics of part I and part II are just the same as that of conventional surfactant. Later, gemini produces a third region of increasing kψ at higher concentrations ([gemini] > 400 × 10−5 mol dm−3, part III). Detail and systematic elucidation about the effect of surfactants are mentioned and discussed in the text. Binding constants (KS for [Zn(II)-Trp]+ and KN for ninhydrin) and rate constant (km in geminis) were determined by nonlinear least squares regression technique. The kinetic results acquired can reasonably be interpreted by pseudo-phase model of surfactant micelles.
      PubDate: 2019-10-23
       
  • Light-responsive vesicles based on azobenzene containing imidazolium
           surfactants and sodium oleate
    • Abstract: Abstract In this work, three light responsive imidazolium surfactants containing azobenzene moiety (CmAZOCnIMB, m = 0, 2, 4 and m + n = 6), namely, 1-[2-(4-phenylazo-phenoxy)-ethyl]-7-methylimidazolium bromide (C0AZOC6IMB), 3-[2-(4-phenylazo-phenoxy)-ethyl]-7-methylimidazolium bromide (C2AZOC4IMB), and 5-[2-(4-phenylazo-phenoxy)-ethyl]-7-methylimidazolium bromide (C4AZOC2IMB), were developed. These surfactants showed strong micellization tendency in the aqueous solution with their critical micelle concentrations (cmc) highly depending on the location of azobenzene moiety. Moreover, they also showed innate light response with excellent reversibility attributing to the trans-and cis-isomerization of azobenzene moiety under UV- and visible-light irradiation, respectively. Phase behavior showed that the addition of CmAZOCnIMB in the sodium oleate (NaOA) aqueous solution could induce the apparent growth of aggregates from spherical micelles to vesicles via wormlike micelles. Moreover, the presence of CmAZOCnIMB also endowed the catanionic systems with excellent light response, i.e., the typically reversible vesicle to multi-connected wormlike micelle network transitions. Static light scattering and dynamic rheological measurements were employed to characterize the turbidity and viscosity variation during the transitions. The morphological changes between vesicles and wormlike micelles were demonstrated by cryogen transmission electron microscopy (cryo-TEM) observation. Moreover, the transition mechanism was illustrated by 1H NMR and 2D Noesy spectra. Graphical Abstract
      PubDate: 2019-10-13
       
  • Improving in vitro biocompatibility of gold nanorods with thiol-terminated
           triblock copolymer
    • Abstract: Abstract Gold nanorods (AuNRs) are usually synthesized using cetyltrimethylammonium bromide (CTAB) surfactant as a structure-directing agent. CTAB is reported to form a tightly bound cationic bilayer on AuNR surface with the cationic trimethylammonium head group exposed to the aqueous media. However, CTAB is also known to be highly toxic in both in vitro and in vivo experiments. In this work, we investigated the cytotoxicity, colloidal stability and optical properties of AuNRs before and after substitution with thiol-terminated triblock copolymer of ethylene oxide-propylene oxide (PEO-PPO-PEO), or Pluronic F127® (PF127). For that, PF127 was first chemically functionalized with 3-mercaptopropionic acid (MPA) and further used as stabilizer for the AuNRs by replacing CTAB molecules. Unmodified PF127 was also tested and used as a control for biological experiments. Morphology of coated AuNRs was characterized by visible spectroscopy, transmission electron microscopy, zeta potential, and dynamic light scattering. We found that coating with PF127-SH guarantees both stability and biocompatibility of AuNRs for at least 45 days, besides improving cell viability when compared to the PF127-coated AuNRs, even after 72 h treatment. In addition, this new polymer coating can also provide hydrophobic domains assembled into the PPO blocks, which could be further loaded with organic active ingredients. The obtained results show the potential of this nanostructured system for future developments in multifunctional nanoplataforms for clinical applications such as drug delivery, hyperthermia, photodynamic therapy, and diagnostic imaging of cells and tissues.
      PubDate: 2019-10-10
       
  • Molecular brushes with poly-2-ethyl-2-oxazoline side chains and aromatic
           polyester backbone manifesting double stimuli responsiveness
    • Abstract: Behavior of grafted copolymers composed of aromatic polyester (PAPE) backbone and poly-2-ethyl-2-oxazoline (PEOZ) side chains differing in grafting density in aqueous solutions was studied when heated at various concentrations and pH using static and dynamic light scattering and turbidimetry. Aggregates and individual macromolecules were registered in solutions at all times. It was shown that the aggregates of the brush with higher PEOZ side chains’ grafting density undergo compaction on heating below phase separation, whereas the size of the loose polymer brush aggregates continuously increases with the increase of temperature. Phase separation temperatures of both copolymers decreased with dilution. Strong influence of pH on the thermosensitivity of both samples was shown, the copolymer solubility being decreased with the acidity decrease. The nature of the pH effect is under discussion. Graphical abstract
      PubDate: 2019-10-08
       
  • The features of poly (vinylimidazole) adsorption on gold surface: a
           molecular dynamics study
    • Abstract: Abstract The simulation of poly (vinylimidazole) (PVI) on Au {111} facet has been carried out to study the adsorption of polymer on gold surface. The molecular dynamics (MD) method has been utilized to get detailed information about the orientation of polymer on metal surface. Our results show that the polymer binds to gold surface via pyridinic nitrogen, and we found that the adsorbed nitrogen-gold distance is around 0.23 nm, which is in good agreement with existing data. The chemisorbed vinylimidazole molecules are mostly oriented perpendicular to gold surface, although the flat and slightly tilted configurational modes are also available. We obtained the adsorption energy value of ~ 59.8 kJ/mol−1, which fitted well with other existing data.
      PubDate: 2019-09-07
       
 
 
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