Surface-initiated atom transfer radical polymerization on spherical silicon gel in water-borne system at ambient temperature

Surface-initiated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) was carried out separately on spherical silicon gel with surface-tethered α-bromoester initiator in aqueous media at ambient temperature. The chemical composition of the PMMA and PHEMA brushes grafted from the silicon gel surface was characterized by FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS). As a result, two kinds of new inorganic/organic hybrid particles were obtained. The thermogravimetric analysis (TGA) results indicated that the content of the grafted polymer was fairly high. The scanning electron microscope (SEM) images revealed the significant change of the morphology between the pristine and polymer modified particles and the polymer modified particles owned core-shell structure. The polydispersity index (PDI) of PMMA brushes was low and the “living” character of the PMMA chain end was further ascertained by the subsequent growth of new MMA, using the PMMA brushes as the macroinitiators.