Graphite oxide(GO) was prepared by the pressurized oxidation method and incorporated into polyimide(PI) matrix to fabricate high-k composite films by in-situ polymerization and subsequent thermal treatment. The result...Graphite oxide(GO) was prepared by the pressurized oxidation method and incorporated into polyimide(PI) matrix to fabricate high-k composite films by in-situ polymerization and subsequent thermal treatment. The results show that the as-prepared GO had good dispersion and compatibility in PI matrix due to the introduction of abundant oxygen-containing functional groups during the oxidation. The residual graphitic domains and the thermal treatment induced reduction of GO further enhanced the dielectric permittivity of the resulting GO–PI composites. The dielectric permittivity of the GO–PI composites exhibited a typical percolation behavior with a percolation threshold of 0.0347 of volume ratio and a critical exponent of 0.837. Near the percolation threshold, the dielectric permittivity of the GO–PI composite increased to 108 at 10~2 Hz and was 26 times that of the pure PI.展开更多
针对目前正渗透膜生物反应器(OMBR)存在的盐度积累问题,借助微滤(MF)膜允许溶解性盐透过的特性,开发了基于MF和正渗透(FO)技术的新型膜生物反应器(MFO-MBR)。实验以MFO-MBR为依托,选取性能优良的聚酰胺(TFC)材质的FO膜,考察工艺处理模...针对目前正渗透膜生物反应器(OMBR)存在的盐度积累问题,借助微滤(MF)膜允许溶解性盐透过的特性,开发了基于MF和正渗透(FO)技术的新型膜生物反应器(MFO-MBR)。实验以MFO-MBR为依托,选取性能优良的聚酰胺(TFC)材质的FO膜,考察工艺处理模拟生活污水过程中的运行性能。结果表明,由于MF的引入,MFO-MBR的盐度被控制在1.7 m S·cm^(-1)左右。正是由于MFO-MBR中的低盐度环境,FO膜的通量得到了提升,最终稳定在6.5 LMH左右。虽然MF的出水劣于FO膜的出水,但是可以直接用作城市杂用水,而FO膜出水中TOC和NH_4^+-N的去除率分别高达96%和98%。TFC污染膜面含有总细胞、蛋白质、ɑ-D-吡喃多糖及β-D-吡喃多糖等有机和生物污染物,且以微生物和蛋白质为主。盐度积累导致的渗透压差的减小是常规OMBR通量衰减的主要原因,而膜污染尤其外部污染则是MFO-MBR通量衰减的主因。展开更多
基金Project(2013JSJJ002)supported by the Faculty Research Fund of Central South University,China
文摘Graphite oxide(GO) was prepared by the pressurized oxidation method and incorporated into polyimide(PI) matrix to fabricate high-k composite films by in-situ polymerization and subsequent thermal treatment. The results show that the as-prepared GO had good dispersion and compatibility in PI matrix due to the introduction of abundant oxygen-containing functional groups during the oxidation. The residual graphitic domains and the thermal treatment induced reduction of GO further enhanced the dielectric permittivity of the resulting GO–PI composites. The dielectric permittivity of the GO–PI composites exhibited a typical percolation behavior with a percolation threshold of 0.0347 of volume ratio and a critical exponent of 0.837. Near the percolation threshold, the dielectric permittivity of the GO–PI composite increased to 108 at 10~2 Hz and was 26 times that of the pure PI.
文摘针对目前正渗透膜生物反应器(OMBR)存在的盐度积累问题,借助微滤(MF)膜允许溶解性盐透过的特性,开发了基于MF和正渗透(FO)技术的新型膜生物反应器(MFO-MBR)。实验以MFO-MBR为依托,选取性能优良的聚酰胺(TFC)材质的FO膜,考察工艺处理模拟生活污水过程中的运行性能。结果表明,由于MF的引入,MFO-MBR的盐度被控制在1.7 m S·cm^(-1)左右。正是由于MFO-MBR中的低盐度环境,FO膜的通量得到了提升,最终稳定在6.5 LMH左右。虽然MF的出水劣于FO膜的出水,但是可以直接用作城市杂用水,而FO膜出水中TOC和NH_4^+-N的去除率分别高达96%和98%。TFC污染膜面含有总细胞、蛋白质、ɑ-D-吡喃多糖及β-D-吡喃多糖等有机和生物污染物,且以微生物和蛋白质为主。盐度积累导致的渗透压差的减小是常规OMBR通量衰减的主要原因,而膜污染尤其外部污染则是MFO-MBR通量衰减的主因。
