【作者】 陈兆安；

【导师】 邓麦村； 商振华； 陈勇；

【作者基本信息】 中国科学院研究生院（大连化学物理研究所） ， 化学工程， 2004， 博士

【摘要】 亲和膜分离技术把亲和色谱与膜分离技术结合起来,利用生物分子的识别功能分离低浓度的生物产品,并以对流传质方式实现快速分离,是备受关注的生物产品纯化分离技术。现有研究多是对商业膜加以改性来制备亲和膜,反应步骤多且容易破坏膜孔结构;而采用含官能团的单体聚合成膜,手段复杂,不易推广放大。本文以醋酸纤维素(CA)为基体膜材料,与含有多氨基官能团的聚乙烯基亚胺(PEI)共混制备微孔亲和膜,为亲和膜的制备提供了简单有效的方法。并利用配基聚乙烯基亚胺的多功能性,进行了螯合吸附重金属离子、分离纯化蛋白、亲和吸附内毒素及胆红素等多种应用的实验研究。在研究制备CA 微孔滤膜的基础上,制备出CA/PEI 共混膜,分别考察了铸膜液组成、共混比例、交联剂用量和工艺条件对膜性能的影响。结果表明,共混PEI 并加以适度交联,可以避免共混对成膜过程及膜结构的影响,且可提高膜性能的稳定性;综合各因素对膜渗透性能、机械性能与吸附性能的影响状况,得到铸膜液的较佳配方:CA/溶剂/甘油=1:10:3.3、共混比0.15、交联剂/PEI=0.5;最佳工艺条件:在50~55℃的近饱和水蒸气环境中诱导分相2 分钟,然后浸入20℃水中固化成膜。应用研究表明,CA/PEI 膜可以在对流传质方式下高效、快速地吸附目标溶质,吸附容量较高,可以满足重金属废水处理、蛋白纯化、内毒素去除和血液净化等多种应用的需要。更多还原

【Abstract】 Affinity membrane has received significant attention in recent decades because itcan provide reliable and efficient method for the purification of biomolecules, byintegrating membrane technology and affinity chromatography. Usually,affinitymembranes are prepared by modifying commercial membranes which can result insome undesired changes in membrane structure. By other methods, as in situcopolymerization of two functional monomers, affinity membrane discs can beprepared, but there are some difficult problems in scale-up.In this dissertation, we developed a simple method to directly prepare affinitymembrane. Cellulose acetate (CA), as a matrix polymer, was blend with PEI, afunctional ligand to prepare CA/PEI microfiltration membranes which combine theproperties of CA in membrane formation, such as high consistency of the pore sizedistribution and mechanical rigidity, and the properties of PEI such as chemicalreactivity and capability of selectively adsorbing biological macromolecules. Themethod can simplify procedures of preparing affinity membranes and the aminegroups of PEI blended in membranes make further modification easier under mildconditions. Thus, we can overcome shortcomings such as change of pore size andloss of rigidity coming from multiple steps under harsh conditions during themodification of commercial polymer membranes. By use of multi-function of PEI,CA/PEI membranes were applied to several separation processes such as purificationof proteins, removal of heavy metal ions, endotoxin and bilirubin and so on.Based on developing a method to prepare CA microfiltration membrane, CA/PEImembranes were prepared. The effects of the composition of casting,blend ratio,amount of crosslinking agent and condition of membrane preparation etc. onmembrane performance were investigated and optimized. With moderatecrosslinking, the stability of membrane performance was enhanced and the effects ofblended PEI on membrane formation and membrane structure can be eliminated.Comprehensive results of the investigations show that the optimal composition ofcasting solution is: the mass ratio of CA, solvent and glycerol of 1:10: 3.3, blendratio of 50% PEI solution and CA of 0.15, mass ratio of amount of crosslinkingagent and PEI of 0.5; the optimal condition of membrane formation is: the castedmembranes were kept at the surroundings of 50~55℃and RH>95% for 2 minutes toinduce phase inversion by absorbing water vapor and evaporating acetone, thenimmersed into 20℃water to remove the solvent and additive and solidify themembrane structure. Application studies show that CA/PEI membranes can achieve efficient adsorptionof goal solutes with high capacity because the binding kinetics dominates theadsorption process with the convective flow of solution through the pores. SoCA/PEI membranes can meet the demands in the applications as wastewatertreatment, purification of proteins, removal of endotoxin, blood purification.更多还原