pH与温度快速响应性P(NIPA-co-AA)凝胶的制备与表征

PREPARATION AND CHARACTERIZATION OF FAST RESPONSIVE THERMO-AND pH-SENSITIVE P(NIPA-CO-AA) HYDROGELS

首次通过激光光散射研究了致孔剂聚乙二醇(PEG)在反应介质中的聚集状态,分析了PEG的致孔机理。通过将凝胶/PEG复合体在一定浓度碱液中的充分浸渍,找到了一种可将致孔剂完全去除的新方法,制得了快速响应的多孔聚(N-异丙基丙烯酰胺/丙烯酸)共聚水凝胶。由称量法测定了水凝胶的体积相转变温度LCST。温敏性退胀动力学研究表明,多孔水凝胶在2 m in内的失水率可达90%以上;在pH敏感性退胀动力学研究中首次发现,该类多孔共聚水凝胶具有脉冲式的退胀过程,这种性能在特殊的药物缓释领域具有潜在的应用前景。

The aggregated state of pore-forming agent poly （ethylene glycol） （PEG） was investigated by laser light scattering （LLS） and scanning electron microscope （SEM）. The pore-forming mechanism of PEG was analysed. The PEG was totally washed out through re-deswelling. Fast-responsive thermo-and pH-sensitive porous poly （N-isopropylacrylamide-co-acrylic acid） copolymer hydrogels were prepared by this method. Lower critical solution temperature （LCST） as volume phase transition temperature was determined gravimetrically. More than 90% of water could he expelled from the porous hydrogels within 2 min. A pulsed deswelling was first discovered during the study.