Self assemblies of ABC triblock copolymer thin films on a densely brush-coated substrate were investigated by using the self-consistent field *** middle block B and the coated polymer form one phase and the alternatin...
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Self assemblies of ABC triblock copolymer thin films on a densely brush-coated substrate were investigated by using the self-consistent field *** middle block B and the coated polymer form one phase and the alternating phase A and phase C occur when the film is very thin either for the neutral or selective hard surface(which is opposite to the brushcoated substrate).The lamellar phase is stable on the hard surface when it is neutral and interestingly,the short block tends to stay on this hard surface...
The generation of arbitrarily shaped nonspherical laser-induced cavitation bubbles is demonstrated with a optical technique. The nonspherical bubbles are formed using laser intensity patterns shaped by a spatial light...
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The generation of arbitrarily shaped nonspherical laser-induced cavitation bubbles is demonstrated with a optical technique. The nonspherical bubbles are formed using laser intensity patterns shaped by a spatial light modulator using linear absorption inside a liquid gap with a thickness of 40 μm. In particular we demonstrate the dynamics of elliptic, toroidal, square, and V-shaped bubbles. The bubble dynamics is recorded with a high-speed camera at framing rates of up to 300 000 frames per second. The observed bubble evolution is compared to predictions from an axisymmetric boundary element simulation which provides good qualitative agreement. Interesting dynamic features that are observed in both the experiment and simulation include the inversion of the major and minor axis for elliptical bubbles, the rotation of the shape for square bubbles, and the formation of a unidirectional jet for V-shaped bubbles. Further we demonstrate that specific bubble shapes can either be formed directly through the intensity distribution of a single laser focus, or indirectly using secondary bubbles that either confine the central bubble or coalesce with the main bubble. The former approach provides the ability to generate in principle any complex bubble geometry.
Injectable hydrogels are attractive materials for tissue engineering as they provide fast reaction rates, low heat release, and biocompatibility for cell proliferation and permanent interface with surrounding tissue. ...
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Injectable hydrogels are attractive materials for tissue engineering as they provide fast reaction rates, low heat release, and biocompatibility for cell proliferation and permanent interface with surrounding tissue. A series of injectable poly(ethylene glycol) dimethacrylate (PEGDMA) hydrogels with four different weight fractions of hydroxyapatite (HA) particles were prepared and thermal and mechanical properties evaluated. The cytocompatibility was assessed by examining the viability and morphology of human mesenchymal stem cells (hMSCs) seeded on the hydrogels. The in situ crosslink process displayed a vast decrease in the maximal temperature and an increase in the maximal temperature time. Cytocompatibility evaluation by MTT assay, scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) showed that the cells on the composite hydrogels possessed better viability and adherence than the hydrogels without HA. The results indicated that composite hydrogels have potential as injectable materials for tissue engineering application.
This paper reviews our recent research efforts on the toughening and multifunctional properties of a class of nanoclay/thermoplastics composites, especially nanoclay/PA6 and nanoclay/*** embrittlement of the polymer m...
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This paper reviews our recent research efforts on the toughening and multifunctional properties of a class of nanoclay/thermoplastics composites, especially nanoclay/PA6 and nanoclay/*** embrittlement of the polymer matrices due to the incorporation of clay nanoparticles is critically *** of toughening and related mechanisms are studied and include: (a) hybridizing clay with rubber and (b) introducing submicrometer voids in the *** on functional properties of electrical conductivity and fire retardancy combined with superior-toughness are also addressed.
Size-controllable and vertically-oriented TiO2 nanotube(TNT)arrays were fabricated using anodic oxidation method from pure titanium sheets in electrolyte *** with the TNT arrays as the working electrode,a thin film of...
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Size-controllable and vertically-oriented TiO2 nanotube(TNT)arrays were fabricated using anodic oxidation method from pure titanium sheets in electrolyte *** with the TNT arrays as the working electrode,a thin film of polypyrrole(Ppy)was synthesized into the TNT arrays via the electrochemical *** the process,the appearance of redox peaks in cyclic voltammetry curves of the resulting films indicates the occurrence of *** morphology,the molecular structure, crystallization and optical properties of the TNT arrays and the resulting polymer were investigated by field-emission scanning electron microscopy(FESEM),X-ray diffractometry(XRD),Fourier transform infrared spectroscopy(FTIR),and UV-vis spectrum analysis,respectively.A dual-layered photoreceptor containing the nanocomposite film as the charge generation layer(CGL)was designed and *** is found that the photoreceptor based on Ppy/TiO2 nanotubes as CGL exhibits remarkable photoconductive performance.
The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its...
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The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. Studies on these methods are also encouraging and many kinds of water-soluble and alcohol-soluble derivatives have appeared. In this article, hydroxybutyl chitosan, a new type of thermosensitive polymer, was prepared through the chemical modification of 1,2-epoxybutane. Hydroxybutyl chitosan solution underwent sol/gel phase transition at a certain temperature lower than 20 0C, however, at high temperature, hydroxybutyl chitosan can form hydrogel with a certain mechanical strength. Hydroxybutyl chitosan could be an ideal themosensitive material applied in drug delivery system, tissue engineering and other biomedical fields.
The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its...
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The insolubility in neutral condition is a major problem that confronts the further development of processing and uses of chitosan. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. Studies on these methods are also encouraging and many kinds of water-soluble and alcohol-soluble derivatives have been prepared. In this article, hydroxybutyl chitosan, a new type of thermosensitive polymer, was prepared through the chemical modification of 1,2-epoxybutane. According to the FT-IR spectra, hydroxybutyl chitosan has the same basic structure as chitosan, and hydroxylbutyl group has been linked in the main chain. XRD shows that the solubility of hydroxybutyl chitosan has been improved. Hydroxybutyl chitosan solution underwent sol/gel phase transition at a certain temperature lower than 20 °C, however, at high temperature, hydroxybutyl chitosan can form hydrogel with a certain mechanical strength. Hydroxybutyl chitosan could be an ideal thermosensitive material which can be applied in drug delivery system.
A reductive kinetic study of amperometric NO2 gas sensing at the Pt/Nafion® electrode (or cathode) has been investigated in the concentration range of 0-25 ppm. The Pt/Nafion® electrode was prepared using an...
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