Effect of montmorillonite on the swelling behavior and drug-release behavior of nanocomposite hydrogels

A series of nanocomposite hydrogels were prepared from various ratios of N-isopropylacrylamide (NIPAAm) and organic montmorillonite (MMT). The influence of the extent of MMT in the NIPAAm/MMT nanocomposite hydrogels on the physical properties and drug-release behavior was the main purpose of this study. The microstructure and morphology were identified by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The results showed that the swelling ratios for these nanocomposite hydrogels decreased with increase in the content of MMT. The gel strength and Young's modulus of the gels also increased with increase in the content of MMT. XRD results indicated that the exfoliation of MMT was achieved in the swollen state. Finally, the drug-release behavior for the gels was also assessed. (C) 2003 Wiley Periodicals, Inc.