【作者】 喻应霞；

【导师】 姜忠义；

【作者基本信息】 天津大学 ， 化学工艺， 2006， 硕士

【摘要】 手性物质的拆分具有非常重要的理论与应用价值,但也具有很大的难度,结合分子印迹技术与膜分离技术的分子印迹膜有可能成为手性物质的识别与分离的新介质。本研究首先制备出新型的分子印迹膜,并实现了水相中手性氨基酸的高效拆分。本文以L-苯丙氨酸(L-Phe)为印迹分子,选取富含羟基和氨基的多功能团聚合物壳聚糖(CS)为基本成膜材料,通过相转化法结合碱液处理与硫酸交联两种后处理方式制备了L-Phe分子印迹CS膜,采用红外光谱(FT-IR)、扫描电镜(SEM)对膜的组成和结构进行了表征,考察了热处理温度、印迹分子含量及原料液中乙醇浓度等对膜用于水溶液中L-, D-Phe的拆分时手性分离能力的影响;采用溶胶-凝胶法制备了L-Phe分子印迹壳聚糖/正硅酸乙酯(CS/TEOS)杂化膜,采用FT-IR、SEM对膜的组成和结构进行了表征,考察了热处理温度、TEOS含量等对膜手性拆分性能的影响;采用溶胶-凝胶法制备了L-Phe分子印迹壳聚糖/γ-缩水甘油醚基丙基三甲氧基硅烷(CS/GPTMS)杂化膜,通过FT-IR、SEM、能谱分析(EDX)、29Si固体核磁(29Si NMR)、X-射线衍射(XRD)、热重分析(TG)等多种手段对膜的组成、结构与热稳定性进行了表征;采用静态吸附法对膜的结合容量与吸附选择性进行了测定;并考察了热处理温度、反应时间、GPTMS含量及原料液浓度等对膜手性拆分性能的影响。结果表明,同空白膜相比,分子印迹CS/GPTMS杂化膜对印迹分子的特异性吸附能力明显提高,印迹分子在印迹膜内的传递符合“优先吸附、延迟扩散”机理,分子印迹CS/GPTMS杂化膜的分离因子可达到4.5,较好的实现了水相中的L,D-苯丙氨酸拆分。更多还原

【Abstract】 Optical resolution is of obvious importance in both theory and reality, and of great challenge. Molecularly imprinted membranes (MIMs), which combine the advantages of molecular imprinting and membrane technology, will potentially become novel separation media for the recognition and separation of chiral substances. In this work, novel MIMs were prepared and efficient separation of L, D-amino acids in aqueous solution was realized.MIMs were prepared using L-phenylalanine (L-Phe) as template, chitosan (CS) with large numbers of amine groups and hydroxyl groups as a multifunctional polymer and bulk membrane matrix. Firstly, molecularly imprinted and control CS membranes were prepared by phase conversion method together with aqueous alkali or sulfuric acid treatment. The chemical composition, structure and morphology of the CS membranes were obtained by FT-IR and SEM. The effect of heat-treatment temperature, template content and ethanol concentration in feed on the ability of membranes for chiral resolution of D, L-Phe aqueous mixtures were investigated.Secondly, L-Phe molecularly imprinted and control chitosan/tetraethoxyortho- silane (CS/TEOS) hybrid membranes were prepared by a simple sol-gel process in aqueous system. The chemical composition, structure and morphology of CS/TEOS hybrid membranes were obtained by FT-IR and SEM. The effects of heat-treatment temperature and TEOS content on the chiral resolution ability of the membranes were investigated.Finally, L-Phe molecularly imprinted and control chitosan/γ-glycidoxypropyl- trimethoxysilane (CS/GPTMS) hybrid membranes were prepared by a similar sol-gel process as above-mentioned. The chemical composition, physical structure and thermal stability of the hybrid membranes were characterized by FT-IR, SEM, EDX, 29Si NMR, XRD and TG. The binding capacity and selectivity of the membranes were obtained by binding experiments. The effects of reaction time, heat-treatment temperature, GPTMS content and feed concentration on the chiral resolution ability of the membranes were investigated. The results indicated that molecularly imprinted CS/GPTMS hybrid membranes showed improved specific adsorption selectivity towards templates compared with control membranes. The transport of L- phenylanaline through MIMs fit the mechanism of“preferential sorption, retarded更多还原