Search

Carbon microfibres (CMFs) were synthesised on SiO2 particles by catalytic chemical vapour deposition at 1200°C using ethanol as carbon precursor, iron nitrate as the catalyst precursor, and nitrogen as a carrier gas. The structure and morphology of the products were characterised by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. CMFs obtained after a deposition time of 5 h have a diameter of 5-10 μm and a length of a few hundred micrometres. In the deposition process, Fe-Si-O-C droplets were first formed on the surface of SiO2 particles, and then carbon fibres grew as a result of the catalysis of the droplets. Carbon fibres have the higher graphitic structures when the deposition process is conducted at 1200°C. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) microstructures were successfully prepared by hydrothermal synthesis with PEG4000 at 120°C for 24 h. The crystalline phase and morphology of ZnO microstructures were characterised by X-ray diffraction and scanning electron microscopy. The results show that the rod-like, flower-like and dumbbell-shaped ZnO microstructures can be easily controlled by varying the amount of PEG4000. The photoluminescence spectra of ZnO microstructures with different morphology at room temperature show four emission peaks at about 362, 389, 421 and 487 nm. The photocatalytic activities of ZnO microstructures are evaluated by degradation of methylene blue (MB) under ultraviolet light irradiation, and the degradation rates of MB with rod-like, flower-like and dumbbell-shaped ZnO microstructures reached 94.8, 95.4 and 70.9%, respectively. [ABSTRACT FROM AUTHOR]

The article examines proton conductivity of acid doped polybenzimidazole (PBI)/polyimide (PI) and polybenzimidazole (PBI)/polyvinylpyrrolione (PVP) blends. The PBI doped with phosphoric acid is proposed as an electrolyte in intermediate temperature fuel cells and hydrogen sensors. Polymer blends have been used extensively for various purposes. The article prepares PBI/PI and PBI/PVP blends. All of these polymers are suitable for acid doping as a matrix because of the existence of the N-heterocycle in the polymers, which can eventually be used as proton conductors. Temperature dependence of proton conductivity of the blends can still be fitted by a simple Arrhenius relation.