In the emulsion polymerization process

organic polymers carrying functional groups are involved in the elaboration of the hybrid latex in order to improve the chemical bonding between the organic and inorganic components.The organic-inorganic hybrid nanoparticles were synthesized by using 3-trimethoxysilyl propyl methacrylate (MPS) in the authors’ work.In the emulsion polymerization process of MPS and styrene

SiOR groups are hydrolyzed and condensed simultaneously with free radical polymerization when they contact with water.The emulsion stability and the organic-inorganic hybrid microstructures are largely dependent on the hydrolysis-condensation rates

and the competition between free radical polymerization rate and hydrolysis-condensation rate determines the final microstructure of the hybrid materials.Hydrolysis-condensation rate coefficients were measured at different pH values by 29Si liquid-state NMR.It was found that the hydrolysis rate coefficient was the lowest when pH=7.0

and increased significantly in both acidic and basic conditions

while the condensation rate coefficient was the lowest when pH=4.0.An equation was presented to estimate the hydrolysis and condensation rate coefficients at different pH values.