Synthesis and Volume Phase Behaviors of TemperatureSensitive PNIPAMHAMSiO2 CoreShell Hybride Microgels

3Aminopropyl triethoxysilane KH550 was used to modify SiO2 nanoparticles through in situ solgel method. Then, the positively charged SiO2 molecules were covered by negatively charged HA molecules through electrostatic force to form coreshell nanoparticles (HAMSiO2). Furthermore, Nisopropylacylamide (NIPAM) was grafted onto the chain of HA to form temperaturesensitive hybride microgels (PNIPAMHAMSiO2), whose properties of filmforming were characterized by AFM and SEM. Results show that the average diameter and shell thickness of HAMSiO2 particles are 182 nm and 15 nm, respectively. The volume phase transition temperature of temperaturesensitive PNIPAMHAMSiO2 microgels is 32 °C, which is consistent with the lower critical solution temperature (LCST) of PNIPAM solutions. The microgels are spherical on the mica surface under volume phase transition temperature, and the compact film forms on the mica above volume phase transition temperature.