基于环糊精二聚体与紫精聚合物的包结作用制备超分子水凝胶  

Supramolecular Hydrogels Obtained by Host-Guest Interactions of Cyclodextrin Dimers with Viologen Polymer

作　　者：张小军[1] 刘尚钟[1] 吴学民[1] 李姝静[2] 

机构地区：[1]中国农业大学理学院应用化学系,北京100193 [2]北京工商大学理学院化学系,北京100048

出　　处：《化学学报》2012年第19期2066-2072,共7页Acta Chimica Sinica

基　　金：国家科技支撑计划(No.2011BAE06B03-10);北京市教育委员会科技发展面上项目(No.KM201210011006)资助~~

摘　　要：制备了对苯二甲酸连接的环糊精二聚体(α,α-CD Dimer)及紫精聚合物(VP),利用α,α-CD Dimer与VP之间的主客体识别作用构筑了一种超分子水凝胶.1H NMR测定结果表明α,α-CD Dimer和VP的主客体相互作用是通过α-CD空腔和VP形成包结络合物进行的.环糊精二聚体α,α-CD Dimer和聚合物VP凝胶体系的构筑受环糊精二聚体类型的影响,同时该超分子水凝胶对有竞争作用的客体分子表现出响应性,该超分子水凝胶在竞争性客体分子存在的条件下,可发生小分子诱导的凝胶与溶胶转化行为.此外,该凝胶体系还具有良好的热稳定性.The supramolecular assembly through host-guest complexation between cyclodextrin （CD） hosts and hydrophobic guests is a powerful method of constructing tunable and switchable polymeric networks. Recently, another interesting way to form polymeric networks by using CD-dimers to crosslink guest substituted polymers was reported. In this work, we demonstrate that a,a-CD Dimer and viologen polymer form polymeric hydrogels, a-Cyclodextrin （a-CD） was bound to a terephthalic moiety by the reaction of 6-amino-a-CD with terephthalic acid in DMF to give the a,a-CD Dimer. Viologen polymer were prepared by treatment of 4,4＇-dipyridyl with 1,10-dibromodecane in DMSO by heating for 2 d. Viologen polymer was chosen since viologen polymer is known to be included and held strongly in a-CD. The 1H NMR spectrum of the mixture of the a,a-CD Dimer and VP showed that the signals of VP protons shifted to the lower field. This result indicated the formation of the inclusion complex between CD and VP. To get more insight on the interaction of host-guest complex, we determined the viscosity of the mixture of VP with a,a-CD Dimer. High viscosity enhancements were observed when a,a-CD Dimer was added to VP solutions as a result of the polymer inclusion association. The hydrogel was prepared by mixing VP and a,a-CD Dimer in aqueous solutions at 100℃ for 24 h followed by evaporating the solvent, then adding a little water to give a brown gel. When the VP concentration was 30 mmol/L, increasing the concentration of a,a-CD Dimer, a hydrogel was formed with a phase transition at 30 mmol/L. Additionally, the influences of a,a-CD Dimer concentration, temperature and type of Dimers on the hydrogel formation were also studied. Adding a competitive guest molecule into the hydrogel induced a phase transition into the sol state. The hydrogel also has good thermal stability.

关 键 词：环糊精二聚体 主客体相互作用 超分子水凝胶 紫精聚合物 

分 类 号：O648.17[理学—物理化学]