A novel thermo-sensitive poly(N-isopropylacrylamide) (PNIPAAm)/mesoporous silica SBA-15 nanocomposite has been prepared via an in situ polymerization initiated by a radical. The nanocomposite was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, N₂ adsorption-desorption, thermogravimetric analysis and differential scanning calorimetry. It was confirmed that the polymerization of monomer NIPAAm occurred within the channels of SBA-15 and a coating layer of the polymer was formed along the pore walls with a relatively uniform distribution. The content of polymer in the composite by TG analysis is about 24%. The polymerization and pore filling did not destroy the ordered hexagonal structure of SBA-15; but the surface area, the pore size and the pore volume of the composite were decreased due to the introduction of the polymer. Moreover, the thermo-sensitive property of PNIPAAm was retained in the nanocomposite, which had a lower critical solution temperature similar to that of pure PNIPAAm.

Key words: thermo-sensitive nanocomposite, poly(N-isopropylacrylamide), mesoporous material, SBA-15, preparation, characterization