Radiation synthesis of polymer/clay nanocomposite hydrogels with high mechanical strength

Poor mechanical properties of PNIPAAm hydrogels have limited their applications. Nanocomposite hydrogels (NC gels) which incorporate inorganic clay possess high mechanical strength and other desirable properties. In this paper, we report a facile approach to synthesize NC gels using radiation technique. With exfoliated clay sheets acting as crosslinkers, N-isopropylacrylamide monomers are polymerized and crosslinked to form NC gels under γ-irradiation at room temperature. Apart from regular swelling behavior and interesting performance in thermo sensitivity, the radiation synthesized NC gel (RNC gel) has good optical transparency, high strength and flexibility. Through Micro-FTIR, XPS and TG analyses, a particular chemically crosslinked organic/inorganic network was identified in the RNC gel.