【作者】 赵义平；

【导师】 陈莉；

【作者基本信息】 天津工业大学 ， 材料学， 2008， 博士

【摘要】 光响应形变高分子凝胶,由于材料柔软而湿润,可望成为制备光开关、光控阀门、光传感器等光学微机器器件的新型材料,在某些需精细柔软或潮湿等的特定环境中大展宏图。同时,由于光源安全、清洁、易于使用,易于控制,因此光响应形变高分子凝胶材料与其它环境响应材料相比,无论是在工业领域还是生物医学领域都将具有广阔的应用前景。目前,光响应形变高分子凝胶的研究尚处于起步阶段。为此,本研究尝试通过将具有光异构化作用的偶氮苯基团键入高分子凝胶分子结构中,实现凝胶对紫外光的响应性。通过精心的分子设计,合成了可反应性中间单体AAAB,采用自由基共聚合方法,分别合成了具有紫外光响应性的AAAB与AAm、NIPAAm和AA的共聚高分子,并首次合成了三种具有紫外光响应形变性能的共聚高分子凝胶。采用FT-IR、核磁(¹H NMR和¹³C NMR)、XRD、GPC、DSC等对共聚高分子及凝胶的结构进行了表征,并对共聚高分子及共聚凝胶的紫外光响应性能进行了研究。本文提出一种合成分子侧链含有偶氮苯基团的P（AAm-co-AAAB）共聚高分子及其凝胶的新方法。考察了共聚配比、光照时间等对共聚高分子紫外吸收的影响,研究了共聚凝胶的溶胀性能、紫外光响应性能及力学性能等。研究结果表明,共聚高分子及其凝胶具有良好的紫外光响应性能。首次采用自由基共聚合方法合成出具有温度和紫外光双重响应性能的P（NIPAAm-co-AAAB）共聚凝胶。考察了共聚配比、单体及交联剂浓度等对凝胶溶胀性能、紫外光和温度敏感性、力学性能等的影响,以及紫外光强度和辐照时间等对光响应性能的影响。研究结果表明,共聚凝胶具有温敏性,其LCST受共聚配比、单体及交联剂浓度的影响;共聚凝胶在紫外光辐照下体积收缩,停止光照又逐渐恢复。本研究还首次合成了具有pH和紫外光双重响应性的P（AA-co-AAAB）共聚高分子及其凝胶。研究了共聚高分子及其凝胶的紫外光和pH的双重响应性。研究结果表明,共聚高分子溶液的吸光度受pH值和紫外光辐照的影响。共聚凝胶在紫外光作用下,体积明显收缩,光照停止后,体积又逐渐恢复到原来的溶胀状态,表现出较好的光响应性及可逆性。更多还原

【Abstract】 Photoresponsive hydrogels,with the properties of softness and wetness,is expected to be the novel materials for producing parts of micro-apparatus,such as switch,valve,sensor and so on.Compared to other intelligent polymers, photoresponsive hydrogels will have very brighter prospect in industrial and biomedical cycles because of its safe,clean and easy to be controlled and to be used light source-UV.Now,the research on the photoresponsive hydrogels is just on the primary phase.To achieve the photoresponse to the UV,the functional groups of photoisomerization of azobenzene were copolymerized into the structure of the hydrogels in this study.Through the design of molecular,the reactive intermediate of acrylamido azobenzene（AAAB）was first synthesized,afterwards the copolymers of AAAB and AAm,NIPAAm and AA were synthesized by the approach of copolymerization and three kinds of photoresponsive hydrogels were synthesized for the first time.The structures,molecular weight and thermal properties of the copolymers and their hydrogels were characterized by the FT-IR,¹H NMR,¹³C NMR, XRD,GPC,DSC ect.,and the properties of the photoresponse to UV were studied.In this paper,we demonstrated the first example of the synthesis of the eopolymer and its hydrogels of Poly（acryl amide-co-acrylamido azobenzene） （P（AAm-co-AAAB））which contains groups of azobenzene in the side chains.The effects of the molar ratio of AAm to AAAB and the time of UV irradiation on the photoresponse of the copolymer,and the properties of swelling,photoresponse to UV and strength were studied.The results indicated that the copolymer and its hydrogels had the photoresponse to UV.The copolymer hydrogels of P（NIPAAm-co-AAAB）with the properties of thermo-sensitivity and UV response was synthesized for the first time.The effects of the molar ratio of AAAB to NIPAAm and the concentrations of NIPAAm and MBAA on the properties of swelling,photoresponse to UV,thermo-sensitivity and strength were studied.The effects of the intensity of UV and the time of the irridation on the photoresponse were also studied.The results showed that the thermo-sensitivity of the copolymer hydrogels was affected by the molar ratio of AAAB to NIPAAm and the concentration of MBAA.The volume of the hydrogels shrinked under the UV irradiation,and the higher intensity of the UV irradiation is,the faster of the photoresponse speed is.The copolymer and its hydrogels of P（AA-co-AAAB）with the properties of pH and UV response were also synthesized for the first time.The properties of UV and pH response were studied,and the results showed that the absorption were affected by the pH value and the UV irradiation.The volume of the hydrogels shrinked obviously under the UV irradiation,but resumed gradually when the UV irradiation was stopped, which means the copolymer hydrogels has excellent reversibility of photoresponse.更多还原