QQ客服 官方微博 反馈留言

题名	铝镁尖晶石超滤膜与硅系有机－无机杂化分离膜的研制
作者	张国昌
学位类别	博士
答辩日期	2000-07
授予单位	中国科学院研究生院
导师	谢裕生 ; 陈运法
关键词	溶胶－凝胶法 铝镁尖晶石 超滤膜 有机－无机杂化膜 气体渗透测孔法
其他题名	Preparation and characterization of Spinel(MgAl2O4)Ultrafiltration Membranes and Silica-Based Organic/Inorganic Hybrid Membranes
学位专业	材料化工
中文摘要	本文针对无机膜在高温条件下性能的不稳定性，如脆性、由相变和热震等因素引发的孔径结构和应用性的变化，研制了高热稳定性的MgAl_2O_4尖晶石超滤膜：针对无机膜的分离选择性不高和成型性能差等问题，用溶胶－凝胶法研制了硅系有机－无机杂化分离膜，使之兼具无机材料和有机材料的优良性能。本文以AlCl_3·6H_2O为原料，经AlOOH胶体制备过渡层，并首次尝试应用γ－Al_2O_3相变原理来控制膜孔径大小及其分布。结果表明，所得的α－Al_2O_3过渡层不仅可以满足要求，而且该方法具有成本低、便于设计膜层结构等优点。本文以Al、Mg为原料合成了Mg[Al~iPrO)_4]_2双醇,盐对其在水介质中的水解／胶溶过程作了详细研究，并对pH值、胶体浓度、异丙醇和添加剂的含量及粘度等参数进行了优化。最终制备的膜性能为：孔径13nm左右，厚2μm左右，对BSA的截留率为96％，纯水的渗透速率为55～143kg/(min·cm~2·Pa).在以正硅酸乙酯（TEOS）和苯基－三甲氧基硅烷（PTMOS）为原料，制备硅系有机－无机杂化分离膜过程中，发现在SiO_2膜中引入苯基，不仅有利于避免膜在热处理过程中的易裂等问题，而且可以提高膜的物化性能（如柔韧性）。通过控制前驱物中的苯基的含量，即PTMOS／TEOS的比值（摩尔比），可以设计膜的结构和分离性能。当PTMOS／TEOS的比值从0.58增加到2.32, 在室温和常压下，分离因子α_(O2/N2)和α_(O2/N2)分别由1.42, 1.75增加到5.38, 30.1，但渗透系数P(O2/N2)和P＿（CO2／N2）分别由174.97, 202.69 降低到15.96, 19.95 (10~(-10)cm~3(STP).cm/cm~2.s.cmHg).通过MMA，在SiO_2(C_6H_5)膜中张－C－C－链，制备了SiO_2/(C_6H_5)/MMA体系杂化分离膜。实验发现，－C－C链的引入，可大大地改善膜的成型性能，使膜结构进一步致密化，提高膜对O＿2／N＿2和O＿2／CO＿2的分离系数，并降低对CO＿2／N＿2的分离系数。通过膜的气体分离实验表明，压力小于2MPa时，粘性流可以不记，为表面扩散和努森扩散，压力大于5atm时，表面扩散作用可以忽略不计，为努森扩散与粘性流。本文还用修正的气体渗透测孔法，测定上述制备的几种复合膜的孔径结构。
英文摘要	Although ceramics are known to be thermally and chemically stable, many common ceramic membranes suffer from the sensitivity to high temperature and certain media. The ceramic membranes also have relatively low selectivity. In the processing, there exist still some problems, such as the surface roughness of the as-received support and characterization of the asymmetric membranes. Based on the above-mentioned problems, the following researches have been carried out in this dissertation; (1) preparation of the intermediate layer to modify the support surface; (2) preparation and characterization of the spinel ultra-filtration membrane with high thermal stability; (3) preparation of inorganic/organic hybrid membranes via sol-gel technique, combining the advantages of the organic and inorganic phases, such as the high thermal and chemical stability from the inorganic network, the high selectivity from the organic groups; (4) characterization the asymmetric membranes. The experimental results may be summarized as follows: Due to the surface roughness of support, an intermediate layer was deposited, before the top layer formation, from the boehmite sol using AlCl_3·6H_2O as starting material instead of Al alkoxide. The pore in the layer was created by the phase transition of γ-alumina to α-alumina. The resulted pore size was controlled by the sintering temperature in the range of 3 to 300 nm, and had a narrow distribution. In the processing of MgAl_2O_4 spinel ultrafiltration membrane, aluminum and magnesium double alkoxide was synthesized first as the precursor, and the processing parameters were optimized such as pH value, colloid concentration, proponal content, DCCA addition and the viscosity. The average pore size of the spinel top layer is around 13nm, the layer thickness is 2 μm and its water flux is 55～143 kg/(min·cm~2·Pa). In the preparation of the silica-based organic-inorganic hybrid membranes, the introduction of phenyl group could avoid the brittleness of silica membrane, and improved the physico-chemical performances, such as the flexibility. The membrane micro-structure and its selectivity could be tailored by controlling the mole ratio of PTMOS to TEOS. When the ratio of PTMOS to TEOS increased from 0.58 to 2.32, the separation factors of α_(O2/N2) and α_(CO2/N2) increased from 1.42,1.75 to 5.38, 30.1, and their permeability P_(O2/N2) and P_(CO2/N2) decreased from 174.97, 202.69 to 15.96,19.95 (10~(10)cm~3 (STP)·cm/cm~2·s·cmHg). The further introduction of -C-C-chain into the SiO_2/(C_6H_5)hybrid layer improved the flexibility of the membrane and made its surface smoother. Moreover the separation factors of O_2/N_2 and O_2/CO_2 were increased, but that of CO_2/N_2 was decreased, and the membrane microstructure was also densified. It was also found that gas transport in the hybrid layers, is mainly contributed from surface diffusion and Kundsen diffusion below 0.2 Mpa, and Kundsen diffusion and Poiseuille diffusion above 0.5 MPa. In the last part of the paper, a modified gas-permeation technique was proposed to characterize the resulted membranes.
语种	中文
公开日期	2013-09-26
页码	130
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1930]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	张国昌. 铝镁尖晶石超滤膜与硅系有机－无机杂化分离膜的研制[D]. 中国科学院研究生院. 2000.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。