期刊
POLYMER
卷 47, 期 17, 页码 6123-6130出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.polymer.2006.06.013
关键词
ATR-FTIR; hydrogen bonding; gelation
A variable temperature ATR-FTIR study of the gelation behaviour of a thermo-responsive ABA triblock copolymer (A = poly(N-isopropylacrylamide) and B = poly [2-(methacryloyloxy)ethyl phosphorylcholine]) is reported. Close inspection of selected copolymer and water bands in the temperature resolved spectra provides evidence for the dehydration of the poly(N-isopropylacrylamide) chains above a critical gelation temperature of approximately 37 degrees C, while the central poly [2-(methacryoyloxy)ethyl phosphorylcholine]) chains remain hydrated. A blue shift in the amide I peak and a red shift in the amide II band indicate a reduction in the hydrogen bonding between the PNIPAM amide functional group and the solvent water. This is corroborated by a decrease in the intensity of the amide I peak above the gel point. Evidence of hydrophobic interactions and an indication of the source of the gelation mechanism were observed in the form of a red shift in the antisymmetric CH vibration with increasing temperature. These findings are consistent with the formation of a micellar gel network by the copolymer chains. (c) 2006 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据