A novel sol-gel processing was developed to synthesize polycrystalline cerium-doped lutetium pyrosilicate （Lu2Si2O7Ce, LPS ：Ce） powders under low temperature. It was found that the addition of propylene oxide （PPO...A novel sol-gel processing was developed to synthesize polycrystalline cerium-doped lutetium pyrosilicate （Lu2Si2O7Ce, LPS ：Ce） powders under low temperature. It was found that the addition of propylene oxide （PPO） could promote the formation of Lu-O-Si bonds in precursor, which was beneficial to the formation of LPS phase. X-ray diffraction （XRD） patterns indicated that the single-phased LPS powder was well crystallized at 1050℃. Microstructure observation demonstrated that the synthetic LPS powder was composed of ellipsoidal grains with the mean size of 40 nm. The luminescent properties were characterized by photoluminescence （PL）, X-ray excited luminescence （XEL） and vacuum ultraviolet （VUV） spectroscopy at room temperature. The synthetic LPS：Ce powder emitted a broad emission spectrum centered at about 380 nm, which should be ascribed to the 5d→4f transition of Ce3＋. Decay time of the synthetic LPS：Ce powder was measured to be only 32 ns.展开更多
Poly(dibutyl itaconate-co-isoprene-co-methacrylic acid)(PDIM) elastomer was designed and synthesized by redox emulsion polymerization under mild conditions. PDIM has high molecular weight, relatively high yield, and l...Poly(dibutyl itaconate-co-isoprene-co-methacrylic acid)(PDIM) elastomer was designed and synthesized by redox emulsion polymerization under mild conditions. PDIM has high molecular weight, relatively high yield, and low glass transition temperature(Tg). The structure of PDIM was determined by FTIR and NMR, and the carboxyl content was obtained by titration in a non-proton solvent. Tensile strength and elongation at break increased with increasing carboxyl content. In addition, the interaction between PDIM and silica was elucidated by rubber process analyzer(RPA) and TEM, and the results showed that the silica-PDIM interaction was strong, but the silica-silica interaction was weak.展开更多
SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coat...SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coating layer, were formed at a preparation temperature of 900 ℃. The initial discharge capacities of the bare SnS and SnS-C composite powders at a current density of 500 mA·g^-1 were 695 and 740 mA·h·g^-1, respectively. The discharge capacities after 50 cycles and the capacity retentions measured from the second cycle of the bare SnS and SnS-C composite powders were 25 and 433 mA.h.g-1 and 5 and 89%, respectively. The prepared SnS-C composite powders with high reversible capacities and good cycle performance can be used as Na-ion battery anode materials.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51172139)
文摘A novel sol-gel processing was developed to synthesize polycrystalline cerium-doped lutetium pyrosilicate （Lu2Si2O7Ce, LPS ：Ce） powders under low temperature. It was found that the addition of propylene oxide （PPO） could promote the formation of Lu-O-Si bonds in precursor, which was beneficial to the formation of LPS phase. X-ray diffraction （XRD） patterns indicated that the single-phased LPS powder was well crystallized at 1050℃. Microstructure observation demonstrated that the synthetic LPS powder was composed of ellipsoidal grains with the mean size of 40 nm. The luminescent properties were characterized by photoluminescence （PL）, X-ray excited luminescence （XEL） and vacuum ultraviolet （VUV） spectroscopy at room temperature. The synthetic LPS：Ce powder emitted a broad emission spectrum centered at about 380 nm, which should be ascribed to the 5d→4f transition of Ce3＋. Decay time of the synthetic LPS：Ce powder was measured to be only 32 ns.
基金supported by the National Natural Science Foundation of China(50933001,51221102)the National Science Fund for Distinguished Young Scholars(50725310)+3 种基金the National Basic Research Program of China(2011 CB606003)the Beijing Nova Program(Z131102000413015)the Beijing Municipal Training Program Foundation for the Talents(2013D003034 00041)the Goodyear Tire & Rubber Company
文摘Poly(dibutyl itaconate-co-isoprene-co-methacrylic acid)(PDIM) elastomer was designed and synthesized by redox emulsion polymerization under mild conditions. PDIM has high molecular weight, relatively high yield, and low glass transition temperature(Tg). The structure of PDIM was determined by FTIR and NMR, and the carboxyl content was obtained by titration in a non-proton solvent. Tensile strength and elongation at break increased with increasing carboxyl content. In addition, the interaction between PDIM and silica was elucidated by rubber process analyzer(RPA) and TEM, and the results showed that the silica-PDIM interaction was strong, but the silica-silica interaction was weak.
文摘SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coating layer, were formed at a preparation temperature of 900 ℃. The initial discharge capacities of the bare SnS and SnS-C composite powders at a current density of 500 mA·g^-1 were 695 and 740 mA·h·g^-1, respectively. The discharge capacities after 50 cycles and the capacity retentions measured from the second cycle of the bare SnS and SnS-C composite powders were 25 and 433 mA.h.g-1 and 5 and 89%, respectively. The prepared SnS-C composite powders with high reversible capacities and good cycle performance can be used as Na-ion battery anode materials.
