变温核磁共振对壳聚糖/磷酸甘油盐温敏性水凝胶的初步研究  

Exploring Study of Chitosan/Glycerophosphate Thermosensitive Hydrogel with Variable-temperature NMR

作　　者：曾蓉[1,2] 冯志程[1] SMITH Ray 邵正中[1] 陈新[1] 杨宇红[4] 

机构地区：[1]教育部聚合物分子工程重点实验室复旦大学高分子科学系,上海200433 [2]伦敦大学玛丽女王学院材料系伦敦E14NS英国 [3]伦敦大学玛丽女王学院材料系 [4]复旦大学分析测试中心,上海200433

出　　处：《化学学报》2007年第21期2459-2465,共7页Acta Chimica Sinica

基　　金：教育部新世纪优秀人才支持计划(No.NCET-06-0354);国家自然科学基金(No.20674011);教育部长江学者和创新团队发展计划;欧盟Asia-Link项目(ASI/B7-301/98/679-32)资助项目.

摘　　要：采用变温核磁共振技术对壳聚糖/磷酸甘油盐温敏性水凝胶体系的凝胶化过程进行跟踪研究.实验结果表明,壳聚糖中氢和磷酸甘油盐中磷的化学位移均随着温度的升高而变化,其中壳聚糖中氢的化学位移向高场移动而磷酸甘油盐中磷的化学位移向低场移动.在凝胶温度附近,壳聚糖中H-2(D)的化学位移变化出现转折点,表明其所处的化学环境发生了突变.随着体系中磷酸甘油盐含量的增加或者pH值的增大,壳聚糖中H-2(D)的化学位移愈加偏向高场,体系的凝胶温度则越低.由此,我们提出如下壳聚糖/磷酸甘油盐温敏性水凝胶的凝胶机理:随着温度的升高,壳聚糖通过氨基正离子与磷酸甘油盐形成的静电吸引被破坏,随之由于壳聚糖分子链间形成大量氢键而发生凝胶化.Variable-temperature NMR techniques were applied to monitor the gelation process of chitosan/glycerophosphate （CS/GP） thermosensitive hydrogel system. The results showed that the chemical shifts of protons in CS and phosphor in GP changed together while the temperature was increased. However, the protons in CS shown in ^1H NMR spectra moved to the high field, but the phosphor shown in ^13p NMR moved to the low field. In addition, the chemical shift of H-2（D） in CS showed a turning point around the gelation temperature, indicating that the chemical environment of H-2（D） has been changed dramatically. Moreover, the chemical shift of H-2（D） in CS moved to higher field and the CS/GP system showed the lower gelation temperature with the increase of either GP content or pH value of the CS/GP mixture. Therefore, the gelation mechanism of CS/GP thermosensitive hydrogel was deduced as follows： with the increase of temperature, the electrostatic interaction between CS and GP is broken down, followed by the formation of hydrogen bonds between CS macromolecular chains, which induce the gelation.

关 键 词：智能水凝胶 化学位移 氢谱 磷谱 氢键 静电相互作用 

分 类 号：O648.17[理学—物理化学]