Graft-type Poly（N-isopropylacrylamide-co-acrylic acid） Microgels Exhibiting Rapid Thermo- and pH-responsive Properties
会议名称：《The 4th Joint China/Japan Chemical Engineering Symposium》
会议日期：2007年
学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070305[理学-高分子化学与物理] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学]
关 键 词：graft copolymers microgels poly(N-isopropylacrylamide-co-acrylic acid) rapid response thermo-/pH- dual responsive polymer
摘 要：A novel graft-type poly（N-isopropylacrylamide-co-acrylic acid） （poly（NIPAM-co-AAc）） microgelwith linear grafted poly（NIPAM-co-AAc） side chains was prepared by incorporating the dualstimuli-responsive chains into conventional copolymerized poly（NIPAM-co-AAc） backbones as side chainsthrough a grafted modification of molecular structure. The grafted chains with unfettered ends can unfold andshrink freely in response to environmental stimuli. Due to the mobile nature and the tractive force of thegrafted poly（NIPAM-co-AAc） side chains, the prepared microgels were verified to have a synchronously rapidthermo- and pH-response property. When the environmental temperature was increased suddenly from 25°C toabout 63 °C, the graft-type microgels in ultrapure water deswelled at best 95% by volume within 40 secondsbut the normal-type microgels deswelled only 17% by volume within the same period. The analogous trendswere observed in either alkaline or acid buffered solutions. The graft-type microgels may thus be greatlypotential for use in many applications in which rapid responses to dual environmental stimuli are required.