Synthesis and optical studies of silver nanoparticles (Ag NPs) and their hybrids of smart polymer microgel

Ag nps were synthesized by the chemical reduction method and were optically characterized. the change in size of the nanoparticles and position of surface plasmon resonance was studied as a function of concentration of different reactants by using uv-visible spectroscopy. red shift was observed in the position of spr by increasing the concentration of silver nitrate,sodium hydroxide and ascorbic acid whereas the spr was blue shifted by increasing the concentration of silver seed and cetyl trimethylammonium bromide (ctab).the former shift shows increase whereas the latter indicates decrease in the size of the nanoparticles. the crystalline nature and morphology of the silver nanoparticles was studied by using x-ray powder diffraction (xrd) and atomic force microscopy (afm). these ag nps were hybridized with multiresponsive micro gel system,poly(nisopropylacrylamide- co-acrylic acid),synthesized by emulsion polymerization. the hybrid system was subjected to dynamic laser light scattering (dls) to determine the hydrodynamic radius (rh) of the hybrid micro gels at different ph and different temperatures. under different conditions of ph,variation in vptt value was observed. fluorescence study was also carried out at different ph values to observe the swelling behavior of hybrid system. the photoluminescence (pl) emission intensity decreased with increase in ph which showed that the hybrid micro gels were more fluorescence active at low ph.