Temperature responsive solution partition of organic-inorganic hybrid poly(N-isopropylacrylamide)-coated mesoporous silica nanospheres

A series of poly (N-isopropylacrylamide)-coated mesoporous silica nanoparticle materials (PNiPAm-MSNs) has been synthesized by a surf ace-initiated living radical polymerization with a reversible addition-fragmentation chain transfer (RAFT) reaction. The structure and the degree of polymerization of the PNiPAm-MSNs has been characterized by a variety of techniques, including nitrogen sorption analysis, Si-29 and C-13 solid-state NMR spectroscopy, transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The thermally induced changes of the surface properties of these polymer-coated core-shell nanoparticles have been determined by examining their partition activities in a biphasic solution (water/toluene) at different temperatures.