Materials Science and Engineering: C 2013-05-01

Preparation and characterization of pH- and temperature-responsive nanocomposite double network hydrogels.

Zhiqiang Li, Jianfeng Shen, Hongwei Ma, Xin Lu, Min Shi, Na Li, Mingxin Ye

Index: Mater. Sci. Eng. C. Mater. Biol. Appl. 33(4) , 1951-7, (2013)

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Abstract

A methodology is described for the preparation of pH- and temperature-responsive double network (DN) hydrogels with poly(N-isopropylacrylamide) (PNIPAM) as a tightly crosslinked 1st network, polyacrylic acid (PAA) as a loosely crosslinked 2nd network and graphene oxide (GO) as an additive. GO sheets were first prepared via an oxidation reaction and then dispersed in NIPAM aqueous solution via silanization. Free-radical polymerization of NIPAM was carried out at 20 °C in a water bath, and then subjected to UV light, leading to the formation of pH- and temperature-responsive PNIPAM/AA/GO DN hydrogels. The effects of GO sheets and AA contents on various physical properties were investigated. Results show that PNIPAM/AA/GO hydrogels undergo a large volumetric change in response to temperature. It also exhibits significantly fast swelling/deswelling compared with conventional PNIPAM hydrogel. Moreover, the PNIPAM/AA/GO hydrogels have a much better mechanical property than the conventional PNIPAM hydrogels.Copyright © 2013. Published by Elsevier B.V.