Abstract:Attapulgite (ATP) was modified by γ-aminopropyltriethoxysilane (APTES) as reductant, and then the mono-center and dual-center redox initiation system was constructed by using ammonium cerium nitrate (CAN) and ammonium persulfate (APS) as oxidant, respectively. Hybrid particles ATP grafted with poly(N-isopropylacrylamide) (ATP@PNIPAM) were prepared via surface-initiating graft polymerization (SIP), and characterized by FT-IR, XPS, TGA, and TEM, etc. The grafting efficiencies of both initiation systems were compared, and effects of the oxidant concentrations, hydrogen ion concentrations and polymerization temperature on the grafting ratios for the mono-center initiation system were studied in detail. The experimental results show that the optimal polymerization temperature is 30 ℃, the oxidant concentration is 4 mmol/L and the hydrogen ion concentration is 1.5 mol/L, the grafting efficiency during the whole polymerization process is much higher than that of the dual-center initiation system. Hybrid particles with the grafting ratio of 33.3% were prepared successfully under this condition and show obvious thermosresponsive behavior.