荧光探针研究聚N-异丙基丙烯酰胺水凝胶的相转变

Phase transition of poly(N-isopropylacrylamide) hydrogels determined by fluorescence probe technique

通过自由基溶液聚合制备了非离子PNIPAAm水凝胶 ,考察了交联剂和引发剂对其溶胀比、凝胶化时间以及LCST相转变点的影响 ,发现影响温敏特征的主要因素是PNIPAAm的基团间的相互作用。选用罗丹明B为荧光探针对PNIPAAm水凝胶进行了荧光光谱分析 ,通过荧光强度的变化研究了疏水基在水凝胶溶胀 /收缩过程中的动态行为 ,对PNIPAAm水凝胶的相转变过程进行了探讨。

Non-ionic p(N-isopropylacrylamide) hydrogels were prepared by radical solution polymerization. The effects of crosslinker and initiator on the swelling ratio, gelling time and LCST phase transition point were investigated. Results showed that the main factor intriguing the temperature-sensitivity of p(NIPAAm) hydrogel is the interaction of intramolecular groups. Then based on the fluorescence spectrum of N-isopropylacrylamide hydrogel by using probe rhodamine B, the dynamic behavior of hydrophobic group in terms of hydrogel swelling and shrinking was studied. According to the fluorescence spectrum, the phase transition of PNIPAAm hydrogel was discussed.