Synthesis and LCST behavior of thermosensitive poly (N-isopropylacrylamide)-clay nanocomposites

Abstract

Thermosensitive polymer-clay nanocomposites were prepared via organically modified claypoly(N-isopropylacrylamide) (PNIPAM) nanocomposites. Nanocomposites containing a 5 wt% of montmorillonite exhibited a lower critical solution temperature (LCST) similar to the unmodified PNIPAM hydrogel, and similar phenomena with a large thermal volumetric change and transition kinetics compared to conventional PNIPAM gels. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) suggested that the clay minerals in the nanocomposite were partially exfoliated in a dried state and mostly exfoliated in a swollen state.