Montmorillonite Nanocomposite Hydrogel Based on Poly(acrylicacid-co-acrylamide) : Polymer Carrier for Controlled Release Systems

In this paper, the synthesis of new montmorillonite nanocomposite hydrogel (MMTNH) based on poly (acrylic acid-co-acrylamide) grafted onto starch, is described. Montmorillonite (MMT) as nanometer base, acrylic acid (AA) and acrylamide (AAm) as monomers, ammonium persulfate (APS) as an initiator, N,N-methylenebisacrylamide (MBA) as a crosslinker and starch as a biocompatible polymer were prepared in aqueous solution and their amounts were optimized to attain the highest water absorbance. The optimized swelling capacity in distilled water was found to be 810 g/g. A mechanism for hydrogel formation was proposed and the structure of the product was confirmed using a set of techniques including FT-IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and X-ray powder diffraction. Furthermore, the swelling behaviors of the nanocomposite at different pHs, various salt with different concentrations, the mixture of solvents, were investigated. The methylene blue (MB) dye was used as model drugs to assess the loading and release by MMTNH. The pH response of this MMTNH makes it suitable for acting as a controlled delivery system. The results suggest MMTNH may find applications as promising drug delivery vehicles for drug molecules.