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Vesicles are membrane-enclosed capsules that can store or transport substances. Their structures and the corresponding structural transitions are important to fulfill specific functions. Using dissipative particle dynamics method, we study the complex structure transitions of vesicles that are spontaneously formed by A 6 (B 2 ) 3 type comb-like block copolymers. In the simulations,...
A facile approach to introduce carboxyl groups onto the surface of CdSe quantum dots (QD) was achieved via oleic acid ligands self-assembly, and then CdSe quantum dots/epoxy fluorescence nanocomposites were successfully fabricated. The surface constitution of QD, the better dispersibility of QD in epoxy matrix, and the reactivity with epoxy of carboxyl groups functionalized QD were characterized by...
Water and sodium chloride solubility, diffusivity and permeability in disulfonated poly(arylene ether sulfone) (BPS) copolymers were measured for both acid and salt form samples at sulfonation levels from 20 to 40 mol percent. The hydrophilicity of these materials, based on water uptake, increased significantly as sulfonation level increased. The water permeability of BPS materials in both the salt...
Formation of β-cylindrites of isotactic polypropylene under various wall shear stress (σ w ), supercooled temperature of melt (T e ) and crystallization temperature (T c ) has been investigated by polarized light microscopy (PLM), wide angle X-ray diffraction (WAXD), and differential scanning calorimeter (DSC). To have better control over the thermomechanical history, instead...
This work addresses the question of the intimate coupling of plastic and damaging processes during the deformation of semi-crystalline polymers at small strains. The evolution of the spherulitic structure in the pre-yield strain range under tensile testing is investigated by atomic force microscopy for three semi-crystalline polymers, namely polycaprolactone, poly(1-butene) and polyamide 6. These...
Polymerization kinetics of tri-ethylene glycol dimethacrylate (TrEGDMA)/2,2-azobis-isobutyronitrile (AIBN) mixtures (0.1% w.t.) at different temperatures was investigated by using dielectric relaxation spectroscopy. The dielectric spectra at the polymerization temperatures studied are dominated by high conductivity leading us to employ the electric modulus representation in order to extract information...
Fiberglass-reinforced polymer composites were investigated for potential use as structural dielectrics in multifunctional capacitors that require simultaneous excellent mechanical properties and good energy storage characteristics. Composites were fabricated employing poly(methyl methacrylate), PMMA, as the structural matrix. While barium titanate (BaTiO 3 ) nanopowder was added to the composites...
A combination of spontaneous reactive chemical domains bounded by non-fouling zones provides a means to covalently immobilize biomolecules in structured, spatially defined arrays. These arrays have application in a wide range of biotechnologies including tissue engineering, proteomics, and diagnostics. In this paper, we describe the fabrication of multi-chemistry micropatterns from plasma polymers...
The investigation of a multicomponent catalyst in polyolefin field came up as an alternative for synthesizing bimodal polymers in only one step process under constant reaction conditions.In the present work, new bifunctional catalysts were prepared by combining chromium and metallocene species on the same solid and tested in ethylene polymerization in order to evaluate the possibility of producing...
Non-isothermal crystallization process of polyoxymethylene (POM) from the melts was studied by two-dimensional correlation infrared spectroscopy. A hybrid structure of FCC (1135 cm −1 ) and ECC (904 cm −1 ) during the crystallization from the molten state was found. Non-isothermal kinetics of POM crystallization was also investigated using DSC curves. A newly perturbation-correlation...
Molecular weight dependence of growth and morphology of spherulites of isotactic poly(butene-1), iPB-1, and those of the mixtures with atactic poly(butene-1), aPB-1, were examined by atomic force microscopy (AFM) and polarizing optical microscopy (POM) in order to examine the mechanism of the structural evolution by the branching and re-orientation of lamellar crystals at the growth front. The width...
The failure analysis of reinforcing elements is of great significance to understand the structure-property relationship in polymer composites. Herein, we reported an improved methodology to ascertain and contrast the failure modes from one pair of homologous fracture surfaces of multi-walled carbon nanotubes (MWCNTs)/epoxy samples at high-magnification using scanning electron microscopy. Three possible...
The recently developed differential fast scanning calorimetry (DFSC) is used for a new look at the crystal growth of poly(ɛ-caprolactone) (PCL) from 185 K, below the glass transition temperature, to 330 K, close to the equilibrium melting temperature. The DFSC allows temperature control of the sample and determination of its heat capacity using heating rates from 50 to 50,000 K/s. The crystal nucleation...
A new reactive and functionalized polystyrene with a maleimide moiety at the one polymer end was synthesized with N-(4-(1-chloroethyl)pheyl)maleimide (CEPMI)/SnCl 4 /tetra-butylammonium chloride (TBAC) initiating system. The polymer obtained with the CEPMI/SnCl 4 /TBAC initiating system under the condition of [TBAC]/[SnCl 4 ] = 1 was to be maleimide-type macromonomer with polystyrene...
Oxidations of aniline or aniline hydrochloride have been carried out in ethylene glycol or glycerol and in their mixtures with water. Ammonium peroxydisulfate was used as oxidant. The oxidation of aniline is exothermic and changes in temperature were monitored to follow its progress. The effect of the solvents on the course of oxidation, morphology, and properties of final products has been studied...
A waterborne latex-based technique has been used to prepare acrylic films with laponite contents up to about 25 vol%. The laponite was attached to the surfaces of the latex particles, giving a cellular arrangement of laponite-rich regions at high laponite contents. Two regimes of reinforcement were observed, depending on whether T was above or below T g , reinforcement at T > T g ...
A new acrylamide-type monomer (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide) derived from guaiacol was successfully synthesized. Polymers containing guaiacol moiety were obtained via conventional radical polymerization of this monomer with AIBN as initiator. The influence of reaction time, initiator concentration and temperature on polymers characteristics was studied. Evaluation of the termination mode...
1-Naphthyl isocyanide was polymerized with Ni(II) catalyst in a cholesteric matrix at the liquid crystal (LC) temperature range. The resultant polymers showed optical activity. In this reaction, the structural chirality of cholesteric LC effectively functions to impart one-handed helicity on the corresponding polymers as an optically active atropisomer.
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