Synthesis and characterization of poly(sodium-p-styrenesulfonate)/modified SiO2 spherical brushes

The multistep procedures for preparing novel anionic spherical polyelectrolyte brushes (ASPB) by grafting sodium-p-styrenesulfonate (SSS) from the surface of !-methacryloxypropyl trimethoxy-silane modified SiO2 nanoparticles were demonstrated. The morphology of ASPB was characterized by Transmission Electron Microscopy (TEM) and Scan- ning Electron Microscopy (SEM). The core radius Rc and hydrodynamic radius Rh of ASPB measured by Zeta Potential/Particle Sizer (ZLS) were ca. 50nm and (84.5±1) nm respectively. The percentage of grafting (PG%) of polyelec- trolyte brushes was 4.3% investigated by Thermo-gravimetric analysis (TGA). Detailed characterizations on ASPB were performed by cleaving the grafts from the anchoring surface. The molecular weight (Mw) and polydispersity (Mw/Mn) of brushes were 1.788·10 3 g/mol and 1.6 respectively from Gel Permeation Chromatography (GPC) measurements. Moreover, Rh and !-potential of ASPB in the presence of aqueous NaCl solutions of different concentrations were discussed.