Advanced Materials Research Vol. 711

Abstract: Rutile titanium dioxide whiskers with diameter around 2μm and length up to 45μm have been successfully synthesized via a facile flux method, using anatase titanium dioxide as raw material and a mixture of ZnSO₄7H₂O and Na₂SO₄ as flux. The products were characterised by X-ray diffraction (XRD), scanning electron microcopy (SEM) and energy dispersive spectroscopy (EDS). It turned out that the calcined temperature and the type of flux addition affected the crystal phase and morphology of the final product greatly. The results showed that rutile titanium dioxide whiskers obtained at 850 °C for 4 hours had the most uniform morphology. The possible growth mechanism was briefly discussed.

Abstract: We investigated current-voltage (I-V) characteristics of bulk polyaniline and aniline polymerized inside nanopores of chromium terephthalate dielectric matrix MIL-101. The temperature dependence of electrical conductivity σ (T) of these materials are described by the fluctuation-induced tunneling model (FIT), which means that the main contribution to a net conductivity is caused by contacts between particles of the polyaniline. The comparison of I-V for these two types of materials shown that I-V characteristics of bulk polyaniline are described by the quasi-1D VRH model while for aniline polymerized inside nanopores of chromium terephthalate dielectric matrix MIL-101 by extended FIT model.

Abstract: In this study, a pH/temperature sensitive polymeric hydrogel from poly (lysine methyl ester-diacetoxy tartaric acid) and sodium alginate (PLMD-SA) was prepared via the condensation polymerization. Using indomethacin as the model drug, the controlled drug-release from the resulting pH/temperature sensitive PLMD-SA was evaluated as functions of pH, PLMD content and temperature by UV spectrophotometer. It was found that the release amount of indomethacin in pH=7.4 phosphate buffer solution (PBS) was evidently higher than in pH=2.3 PBS.

Abstract: In this paper, a new pH/temperature-sensitive beads with semi-interpenetrating polymeric network based on sodium alginate(SA) and poly(aspartic acid) derivatives(M-E-PSI) were prepared using as drug delivery carrier. With indomethacin as a drug model，we investigated the release behaviors of indomethacin in different pH value, temperature and ratio of SA/ M-E-PSI. It turned out that the release amount of indomethacin in pH=2.1 phosphate buffer solution(PBS) was evidently higher than that in pH=7.4 PBS. And also, the release amount of indomethacin was also increased with increasing temperature and poly(aspartic acid) derivatives content in the beads.

Abstract: In this paper, the ammonium dichromate and copper nitrate were used as raw materials to prepare the copper chromite, and nanocopper chromite as a catalyst was used to synthesize the monomer dioxanone in diethylene glycol dehydrogenation. Under the strict conditions of no water and no oxygen, the stannous octoate was selected to catalyze ring-opening polymerization of the dioxanone to prepare the polydioxanone. And dioxanone and its polymers were characterized with IR spectroscopy, ¹H NMR spectroscopy, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC ) measurements.

Abstract: Zinc oxide (ZnO) films are grown by two methods-pulse laser deposition (PLD) and radio-frequency magnetron sputtering at various oxygen ambiences. Based on x-ray diffraction spectra and photoluminescence (PL) spectra, effects of the oxygen ambient on the grain size and emission properties of the ZnO films are investigated. For the samples grown by PLD, the PL spectrum consists of a single ultraviolet (UV) peak except one sample deposited at a low O₂ pressure of 7 Pa. All the samples grown by sputtering have both a UV peak and a green emission. The disappearance of the green emission of the PLD samples is ascribed to deficiency of oxygen vacancies (O_v), and the green emission of the sample grown by sputtering is due to abundant O_v. The intensity change of the UV emission is due to the variation of exciton emission, which is related to grain size and stoichiometry. The position shifting of the UV peak of the PLD samples originates from the Zn interstitial-related degradation of stoichiometry.

Abstract: The possible mechanism protecting the organisms against the freezing is shown. The presence of highly soluble proteins with no specific interaction allows the organism surviving the temperature below zero Celsius degree. The role of hydrophobic core and its structure (recognized as accordant with the idealized one) appears to be critical for antifreeze function of protein. The possible application of the model for biotechnological preparation of compounds protecting the solutions against freezing is discussed.

Abstract: Stability and efficiency have drawn much attention in research area. Buffer layers are inserted between the anode electrode (typically ITO) and active layer to obtain better performance. In this article development of different categories of materials as anode buffer layer and their possible mechanisms are reviewed.

Abstract: This study focused on the basic performance and analysis of a newly developed composite filter media used in high temperature filtration for bag house. It consists of basalt and polysulfonamide fibers. Thermal dimensional stability, heat resistance, air permeability and chemical corrosion resistance were tested to reveal the properties. Based on the experimental results, possible analysis showed that the new filter material had excellent performance in heat resistance, air permeability and acid corrosion.