Syntheses, characterization, and antibacterial activity of chitosan grafted hydrogels and associated mica‐containing nanocomposite hydrogels

Chitosan (CS) grafted poly[(acrylic acid)‐ co ‐(2‐hydroxyethyl methacrylate)] (CS‐ g ‐poly(AA‐ co ‐HEMA)) at different molar ratios of AA and HEMA, and the associated nanocomposite hydrogels of CS‐ g ‐poly(AA‐ co ‐HEMA)/mica were synthesized by radical copolymerization. The grafting positions at the amino or hydroxyl groups in the CS were identified by Fourier transform infrared spectroscopy. CS‐ g ‐poly(AA‐ co ‐HEMA) hydrogels were intercalated in the mica and the amount of hydrogel insertion did not affect the spacing of the silicate layers in mica. The higher mica loadings produced a rougher surface of the nanocomposite hydrogel. The water absorbency of the CS‐ g ‐poly(AA‐ co ‐HEMA)/mica nanocomposite hydrogels decreased with increasing levels of mica loading to a lower level than those of the CS‐ g ‐poly(AA‐ co ‐HEMA) hydrogels. Both CS‐ g ‐poly(AA) and CS‐ g ‐poly(AA‐ co ‐HEMA)/mica nanocomposite hydrogels exhibited a higher antiproliferative activity against Staphylococcus aureus than did the neat CS hydrogel with CS‐ g ‐poly(AA) revealing a very pronounced minimum inhibition concentration (MIC) of 1.56 mg mL −1 . The extent of mica loading in the CS‐ g ‐poly(AA‐ co ‐HEMA) nanocomposite hydrogels did not affect the MIC (12.5 mg mL −1 ). © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013