کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5186099 1381095 2007 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Dual thermo- and pH-sensitive poly(N-isopropylacrylamide-co-acrylic acid) hydrogels with rapid response behaviors
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Dual thermo- and pH-sensitive poly(N-isopropylacrylamide-co-acrylic acid) hydrogels with rapid response behaviors
چکیده انگلیسی

Novel dual temperature- and pH-sensitive comb-type grafted poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AAc)) hydrogels were successfully prepared by grafting PNIPAM chains with freely mobile ends onto the backbone of a cross-linked P(NIPAM-co-AAc) network. The prepared comb-type grafted P(NIPAM-co-AAc) hydrogels exhibited a more rapid deswelling rate than normal-type P(NIPAM-co-AAc) hydrogels in ultrapure water in response to abrupt changes from 25 °C to 60 °C. The same was true in buffer solution with a pH jump from 7.4 to 2.0 at 25 °C. Unexpectedly, the comb-type grafted P(NIPAM-co-AAc) hydrogels showed abnormal shrinkage behaviors in a buffer solution when the temperature increased from 25 °C to 60 °C with a pH value fixed at 7.4 or 2.0. In a buffer solution of pH 7.4, when the environmental temperature jumped from 25 °C to 60 °C, the grafted comb-type hydrogels shrank slower than the normal-type hydrogels, while at pH 2.0, the gels shrank faster than the normal-type gels in the beginning, which was followed by a slower shrinking. Interestingly, the much quicker shrinkage of the comb-type grafted P(NIPAM-co-AAc) hydrogels was observed because of the cooperative thermo-/pH-responses when the simultaneous temperature and pH stimuli met from pH 7.4/25 °C to pH 2.0/60 °C. The results of this study provide valuable information regarding the development of dual stimuli-sensitive hydrogels with fast responsiveness.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 48, Issue 6, 8 March 2007, Pages 1718-1728
نویسندگان
, , , ,