Adopting inorganic clay (hectorite) as physical cross-linking agent

a series of temperature-sensitive microgels were synthesized via the surfactant-free emulsion polymerization method.The chemical structure and global shape of the microgels were confirmed by FTIR

XRD and SEM

respectively.The temperature-sensitive behavior of the microgels was investigated by QELS and DSC.It was concluded that the clay used could act as an effective multifunctional cross-linking agent.In addition

the incorporation of tBA comonomer could tune the volume phase transition temperature of the PNIPAM-based microgels and could increase the uniformity of microgel particles.The particle size of the microgels thus prepared ranged from 140 nm to 350 nm.