基于高分子侧链主客体识别构筑光响应超分子水凝胶  

Formation of Supramolecular Hydrogel via Host-Guest Recognition of Hydrophobically Modified Polyacrylamide and α-Cyclodextrin Polymer

作　　者：李姝静[1] 梁海燕[1] 周威[1] 

机构地区：[1]北京工商大学理学院化学系,北京100048

出　　处：《高分子通报》2013年第8期61-67,共7页Polymer Bulletin

基　　金：国家自然科学基金(批准号:NO.21003005);教育部留学回国人员科研启动基金资助项目;北京市教委科技发展面上项目(KM201210011006);北京工商大学青年教师科研启动基金

摘　　要：制备了侧链含α-环糊精(α-CD)的聚丙烯酸(PAA-α-CD)作为主体聚合物,侧链含偶氮基团(Azo)的聚丙烯酰胺(PAM-Azo)作为客体聚合物。利用1 H NMR、2DNOESY NMR方法测定了PAA-α-CD与PAM-Azo间的主客体作用。结果表明,PAM-Azo侧链的trans-Azo基团能够被PAA-α-CD侧链的α-CD包结,而cis-Azo基团不能被α-CD包结。在一定浓度下,PAA-α-CD与PAM-Azo通过主客体间的识别能够形成超分子水凝胶,并且该凝胶具有光响应性。在365nm紫外光光照下,PAM-Azo侧链的trans-Azo转变为cis-Azo,不能被PAA-α-CD侧链的α-CD包结,超分子水凝胶转变为溶胶。而在430nm的可见光光照下,PAM-Azo侧链的cis-Azo转变为trans-Azo,重新被PAA-α-CD侧链的α-CD包结,又可得到超分子水凝胶。A α-cyclodextrin （a-CD） modified poly（acrylic acid） （PAA-a-CD） acting as the host-polymer and an azobenzene-branched polyacrylamide （PAM-Azo） acting as the guest-polymer were prepared. The interaction of PAA-α-CD with PAM-Azo was characterized by 1H NMR and 2D NOESY NMR spectroscopy. The 2D NOESY NMR spectroscopy indicate that trans-azobenzene （trans-Azo） units are bounded strongly within the cavities of PAA-a-CD whereas the cis- azobenzene （cis-Azo） is not bound at all. A supramolecular inclusion complex, formed by PAA-α-CD and PAM-Azo, is accompanied by the formation of a light-responsive hydrogel. Upon photoirradiation with UV light of 365nm, the hydrogel is converted efficiently to the sol phase because the trans-Azo units are converted photochemically to their cis configuratons, where upon the resulting cis-Azo units dissociation from PAA-α-CD. The hydrogel can be recovered from the sol phase by photoirradiation with visible light of 430nm.

关 键 词：环糊精聚合物 主客体相互作用 超分子水凝胶 光响应 偶氮苯 

分 类 号：O648.17[理学—物理化学]