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题名	聚丙烯腈超滤膜的制备
作者	方超平
学位类别	硕士
答辩日期	2011-05-23
授予单位	中国科学院研究生院
导师	万印华
关键词	聚丙烯腈 超滤膜 制备 相转化法 低截留分子量
其他题名	Preparation of polyacrylonitrile ultrafiltration membranes
学位专业	生物化工
中文摘要	聚丙烯腈(PAN)由于诸多优点被广泛用于制备超滤膜，但是聚丙烯腈超滤膜的截留分子量一般较大，对低分子量分子的截留性能并不理想，所以本文的目的是制备出低截留分子量的聚丙烯腈超滤膜，能同时高效截留大分子的牛血清蛋白(BSA)和低分子量的聚乙二醇(PEG 20 000)。为了制备出低截留分子量的聚丙烯腈超滤膜，本文深入研究了相转化法制膜过程中膜液配方和制膜工艺对膜性能和结构的影响，主要包括聚合物分子量和质量分数、溶剂、添加剂的种类和质量分数、膜液预蒸发时间、凝胶浴温度、凝胶浴的种类和质量分数等因素。主要研究内容和结果如下：分别使用了分子量为5万、7万和9万的聚丙烯腈制备超滤膜，发现PAN 9万制得的超滤膜对PEG 20 000的截留性能最好，截留率达到40.36%；并进一步考察了聚合物在不同质量分数下的膜的性能，发现其最合适的质量分数是13%。考察了N，N-二甲基甲酰胺(DMF)、N-甲基-吡咯烷酮(NMP)、N，N-二甲基乙甲酰(DMAc)以及三者两两混合作为溶剂对膜性能的影响，发现使用NMP能制得通量较高同时截留性能最好的膜，而DMF作溶剂制得的膜通量最高但是截留性能最差，并且膜性能不稳定，使用DMAc作溶剂膜通量最小。使用了无机盐、小分子有机物以及水溶性大分子三类添加剂，发现LiCl作为添加剂可制得通量较高的膜，其质量分数为9%时通量可达到252.63 L·m-2·h-1；使用质量分数3%的磷酸作添加剂可以制备出截留性能最好的膜，对PEG 20 000的截留率达到49.21%。考察了不同蒸发时间对膜性能的影响，发现0-120s区间内，蒸发时间越长，膜的截留性能越差；考察了凝胶浴为水时水温（5℃，15℃，25℃，40℃）对膜性能的影响，发现凝胶浴的温度越低，膜的截留性能越好。研究了NaCl、甘油和NMP水溶液作为凝胶浴对膜性能的影响，发现采用NaCl水溶液有利于制备低截留分子量的超滤膜，膜对PEG 20 000截留率随着NaCl质量分数的提高而提高，当其质量分数达到15%时，对PEG 20 000的截留率达到49.87%，而使用另外两种凝胶浴时膜的截留性能下降。
英文摘要	Polyacrylonitrile (PAN) is one of the versatile polymers widely used for preparing ultrafiltration membranes. However, the molecular weight cut-off of most PAN ultrafiltration membranes is too large for the rejection of molecules with low molecular weight. The main objective of this thesis is to prepare PAN ultrafiltration membranes with low molecular weight cut-off, which can reject both the bovine serum albumin (BSA) and PEG 20 000. In this thesis, the effects of casting solution composition and preparation parameters in the phase inversion process on membrane performance were investigated, including molecular weight of PAN, PAN concentration, solvents, different additives, additive concentration, evaporation time, different coagulation bathes, coagulation temperature and concentration. The results could be summarized as follows: As compared with membranes prepared by PAN 50 000 and PAN 70 000, membranes prepared by PAN 90 000 showed the highest rejection of PEG 20 000, which was up to 40.36%. The effect of PAN concentration was further investigated, it was found that the optimal concentration was 13%. Dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), Dimethylacetamide (DMAc) and the mixture of each two of them were used as solvents, and the results showed that membranes prepared with NMP as a solvent had the highest rejection of PEG 20 000 and good flux, while membranes prepared with DMF as a solvent had the highest flux and the lowest rejection and the worst reproducibility. Inorganic salt, small organic molecule and water-soluble polymers were used as additives, the results showed that high flux membrane could be made by the addition of LiCl, and the flux reached 252.63 L·m-2·h-1 as the concentration of LiCl was up to 9%. And membranes with rejection as high as 49.21% were made by the addition of phosphoric acid(3%). The effect of evaporation time (0s，30s，60s，120s) was investigated, and the result showed that the flux and the rejection and the porosity all decreased with increasing evaporation time. The coagulation temperature could also affect the membrane performance, and the rejection increased with decreasing temperature. Solutions of NaCl, Glycerol and NMP in different concentration(5%、10%、15%) were used as coagulation, it was found that with increasing NaCl concentration, the rejection of PEG 20 000 was improved, and the rejection was up to 49.87% when 15% NaCl was used. While the rejection of PEG 20 000 decreased when the other two solutions were used.
语种	中文
公开日期	2013-09-24
页码	80
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1734]
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	方超平. 聚丙烯腈超滤膜的制备[D]. 中国科学院研究生院. 2011.

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