کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5188983 1381174 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
ATR-FTIR studies of a thermo-responsive ABA triblock copolymer gelator in aqueous solution
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
ATR-FTIR studies of a thermo-responsive ABA triblock copolymer gelator in aqueous solution
چکیده انگلیسی
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 °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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 47, Issue 17, 9 August 2006, Pages 6123-6130
نویسندگان
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