Using sodium tungstate and cesium carbonate as raw materials, cesium tungsten bronze (CsxWO3) powders were synthesized by low temperature hydrothermal reaction with citric acid as the reducing agent. Effects of annealing in different atmosphere on the near-infrared shielding properties of CsxWO3were investigated. The microstructure of CsxWO3powders was characterized by X-ray diffraction. The CsxWO3films were prepared on glass using polyvinyl alcohol solution as film-forming agent, and the optical transmission properties of CsxWO3films were investigated. The results indicate that the near-infrared shielding ability of samples after annealed at 200°C in the air atmosphere did not deteriorate apparently, but the 400°C-annealed samples in the air atmosphere showed apparent decrease of near-infrared shielding properties. Annealing in the carbon powder atmosphere had no apparent effects on the properties of CsxWO3particles. As for the N2annealing, the 500°C-annealed samples showed best improved near-infrared shielding as well as high transparency in the visible light region.
Sodium tungsten bronze NaxWO3 powders have been prepared by hydrothermal method using sodium tungstate as raw material and citric acid as reducing agent, followed by annealing under the inert gas N2 atmosphere. The prepared powders were confirmed as tetragonal sodium tungsten bronze Na0.1WO3 by X-ray diffraction. The SEM observation showed that the as-prepared Na0.1WO3 particles exhibited rod-like morphology with about 20 μm in length and 5 μm in diameter. The influence of pH value of the precursor solution and annealing temperature on the synthesized powders were also investigated. The results indicated that sodium tungsten bronze NaXWO3 would not be obtained when the pH value of the precursor solution decreased to pH=1 or the annealing temperature was lower than 700°C by this hydrothermal method. Additionally, as the wavelength increasing, the transmittance of prepared NaxWO3 exhibited higher visible light transparency with reaching up to about 58% and a downward trend in near-infrared area, which indicates that the prepared Na0.1WO3 have potential application as near-infrared shielding material.
CIGS thin films were deposited on soda lime glass by one-step magnetron sputtering using a single quaternary-CIGS target in stoichiometric proportions. The influences of substrate temperature on the structural, optical, and electrical properties of Cu(In,Ga)Se2 (CIGS) thin films were investigated. The phase structure of CIGS thin films was characterized by X-ray diffraction (XRD). The morphology and thickness of CIGS thin films were observed by Scanning Electron Microscope (SEM). The absorption coefficient of CIGS thin films was measured by Ultraviolet-visible Spectrophotometer. Four-point probe method was used to test the resistivity of CIGS thin films. Based on the results of characterization, the increase in crystallite size of CIGS was found to be significantly noticeable with increasing substrate temperature. UV-vis measurement analysis suggested that CIGS thin films deposited at different substrate temperatures had high absorption coefficient (~104 cm-1) and optical band gap (1.07-1.23 eV). The substrate temperature dependence of the resistivity of the films indicated that the resistivity of the films fall to about 0.5 Ω۰cm as the substrate glass was heated up to 300 °C.
In order to reduce the postoperative inflammation by the slow release of drugs at the beginning of implanting, drug-loaded apatite coatings and chitosan-apatite composite coatings on the NiTi alloy surface were prepared in the Simulated Body Fluid concentrated by five (5×SBF) under constant bubbling of carbon dioxide gas by biomimetic synthesis method. The composition and surface morphology of the coatings were studied using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Additionally, a bacterial inhibition test was conducted for evaluating the drug slow release effects from the drug-loaded coatings. The results indicated that the porous apatite coatings with the flake structure could be deposited using the 5 times Simulated Body Fluid, and the drug-loaded chitosan-apatite composite coatings with better drug slow release effect were obtained. The incorporation of chitosan into the coatings could effectively control the drug release rate and was favorable for achieving better drug slow release effects.
In order to further improve the corrosion resistance and bioactivity of NiTi alloy, TiO2-SiO2-HAP (hydroxyapatite) composite films with different composition were prepared on NiTi alloy substrate by a sol-gel method. The phase composition, surface morphology, interface adhesive strength and corrosion resistance were studied. The results indicated that the composite film heat-treated at 500°C showed amorphous state, and with increasing of heat-treatment temperature, crystals of CaSiO3, anatase TiO2 and hydroxyapatite (HAP) appeared. The composite film with higher (TiO2-SiO2) content was more uniform and smooth, and had higher interface adhesive strength with the substrate. With the decreasing of (TiO2-SiO2) content, the composite films tended to become irregular, and tiny crack clusters with ringy distribution appeared when the (Ti+Si)/Ca molar ratio was decreased to 25/75, which led to decrease of interface adhesive strength to some extent. The anodic polarization curves indicated that NiTi alloy coated with TiO2-SiO2-HAP composite films had an apparent improvement of corrosion resistance, with an obvious decrease of passivation current.
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