MONTE-CARLO SIMULATION OF THE SOL-GEL PROCESS FOR THE HYDROLYSIS AND POLYCONDENSATION OF TIN TETRA-N-BUTOXIDE

The sol-gel process for the hydrolysis and polycondensation of tin tet ra-n-butoxide in butanol was followed by viscosity measurements. The p recipitation of tin-containing ultrafine particles was observed withou t any variation in the solution viscosity in the absence of diethylene glycols, while the viscosity increase was made without any precipitat ion by the addition of diethylene glycol. The induction period and the rate of the viscosity increase after the induction period was indepen dent of the diethylene glycol content but depended upon the water cont ent. The Monte Carlo simulation data were consistent with data for the viscosity experiment. The simulation was based on a kinetic model of the slow hydrolysis of tin tetra-n-butoxide, the reverse reaction of h ydrolysis, and the polycondensation of the hydroxy derivatives.