A COMPARATIVE STUDY OF PARTICLES CHARACTERISTICS, TEMPERATURE SENSITIVITY AND MORPHOLOGY OF PEG/POLY (NIPAM-CO-AMPS) MICROGELS

The temperature sensitive copolymer of microsize hydrogels consist of N-isopropylacrylamide (NIPAM) and 2- acrylamido-2 methylpropanesulphonic acid (AMPS) have been synthesized by soap free emulsion polymerization method in the presence of polyethylene glycol (PEG) as macro initiator and N, N´-methylenebisacrylamide (NMBA) as crosslinker. In this work, Dynamic Light Scattering (DLS), Transmission Electron Microscope (TEM) and Atomic Force Microscope (AFM) technique were used for structural analysis of microgels. It was found that particle size observed by TEM and AFM were spherical with a diameter around 103.0 nm to 133.1 nm and 121.1 nm to 189.0 nm. While DLS measurement shows narrow particle size distribution with hydrodynamic diameter from 343.6nm to 528 nm at a temperature 25°C and 132.5nm to 414.4nm at temperature 50°C depending on the AMPS content in Microgels samples. The surface roughnesses of particles were observed to be increasing with increased AMPS content. Moreover, decrease in hydrodynamic diameter from 25°C to 50°C revealed the temperature sensitivityproperty of microgels.