In-situ synthesis of CuO nanoparticles in P(NIPAM-co-AAA) microgel, structural characterization, catalytic and biological applications

The production of new multi-responsive poly(N-isopropylacrylamide-allyl acetic acid) [P(NIPAM-AAA)] copolymer microgel by free radical emulsion polymerization is reported. Inside this copolymer microgel CuO nanoparticles were generated by in situ reduction of copper nitrate followed by the air oxidation process, their fabrication is confirmed by powdered X-ray diffraction analysis and the average size of CuO NPs was found to be 24 nm having monoclinic shapes. By using dynamic laser light scattering the swelling & de-swelling behaviour of the pure microgel was examined at different temperature and pH values. The copolymer microgel becomes unstable at low pH as well as at high temperature values respectively. UV–visible spectra show a red shift in surface plasmon resonance λSPR of CuO nanoparticles. The catalytic property of hybrid microgel was inspected by observing the reduction of 4-nitrophenol into 4-aminophenol in the presence of excess NaBH4 with various concentrations of catalyst at room temperature. The hybrid microgels also have good anti-bacterial activity against both Gram-positive (C. albicans) and Gram-negative (E. coli) bacteria. Keywords: Polymerization, NIPAM-AAA microgel, CuO NPs, Catalytic activity