pH响应的聚丙烯酰胺形状记忆水凝胶

pH Induced Shape Memory Polyacrylamide

通过在聚丙烯酰胺网络中引入丹磺酰胺基团,成功合成了具有p H响应能力的形状记忆材料。p H>5时丹磺酰胺基团间产生的疏水聚集作为形状记忆材料中的可逆相,这种疏水聚集可在p H=2时由丹磺酰胺基团的质子化而消失。聚丙烯酰胺中的固有化学交联点则作为形状记忆聚合物中的固定相。实验表明,这种材料可在p H=5时被固定为暂时形状,这种暂时形状在p H=2时得以回复到初始形状。其回复率及固定率分别可达95.4%和94.6%。

A p H sensitive shape-memory polymer（ SMP） was successfully prepared by grafting dansyl group into the network of polyacrylamide（ p AAm）. The hydrophobic aggregation at p H 5 between deprotonated dansyl group serves as a reversible phase,which would collapse at p H 2 as the dansyl group is protonated. The cross-linked p AAm chains serve as a fixing phase. It is shown that this material can be processed into temporary shape as we need at p H 5 and recover to its initial shape at p H 2. The recovery ratio and the fixity ratio are 95. 4% and 94. 6%,respectively.