Controlled post‐synthesis grafting of thermoresponsive poly(N‐isopropylacrylamide) on mesoporous silica nanoparticles

Ordered mesoporous silica nanoparticles with pore diameter of 5 nm were synthesized by modification of the sol‐gel synthesis method. Post‐synthesis two‐step grafting of thermoresponsive poly(N‐isopropylacrylamide) inside the mesopores of the nanoparticles was carried out by distillation–precipitation polymerization of the methacryloxy‐functionalized mesoporous nanoparticles with N‐isopropylacrylamide monomer. A precise control on the quantity of the grafted polymer was achieved by changing the ratio of monomer to methacryloxy‐functionalized nanoparticles. The polymer‐grafted hybrid nanoparticles obtained were fully characterized by infrared spectroscopy, X‐ray diffraction, dynamic light scattering, transmission electron microscopy, thermal, and gas‐volumetric analyses, which clearly showed presence and thermoresponsive behavior of the polymer inside the mesopores with the preservation of the characteristic mesoporous structure of the nanoparticles. Copyright © 2015 John Wiley & Sons, Ltd.