ATOMISTIC MODELING OF SILICA-BASED SOL-GEL PROCESSES

Density Functional Theory is used to study water, methanol, ethanol, T MOS, and TEOS molecules and the most important silica clusters partici pating in sol-gel processes. Calculated bond lengths, bond angles and electric dipole moments compare well with experimental data. The energ y of these molecules is reported and used to discuss the energetics of the hydrolysis and condensation reactions. Molecular Dynamics is empl oyed to simulate liquid water, methanol, ethanol, TMOS, TEOS and exper imental sol-gel solutions. Calculated densities and enthalpies of vapo risation compare well with experimental data. Preliminary results are presented for MD simulations of sol-gel solutions.