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 gamma-methacryloxypropyl trimethoxy-silane modified SiO2 nanoparticles were demonstrated. The morphology of ASPB was characterized by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). The core radius R-c and hydrodynamic radius R-h of ASPB measured by Zeta Potential/Particle Sizer (ZLS) were ca. 50nm and (84.5+/-1) nm respectively. The percentage of grafting (PG%) of polyelectrolyte 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 (M-w) and polydispersity (M-w/M-n) of brushes were 1.788.10(3) g/mol and 1.6 respectively from Gel Permeation Chromatography (GPC) measurements. Moreover, R-h and zeta-potential of ASPB in the presence of aqueous NaCl solutions of different concentrations were discussed.