Atomistic simulation of the sol formation during synthesis of organic/inorganic hybrid materials

Atomistic modelling was employed to investigate interactions between the precursors used in preparation of organic/inorganic polymer hybrids. Three molecular systems composed of different kinds of organofunctionalised silanes and an organic polymer in aqueous solution have been simulated, representing various model stages of the hydrolysis reaction during the sol/gel processing. The equilibrium configurations obtained by Molecular Dynamics were analysed in order to elucidate the extent of the hydrogen bonding network and clustering of components within the systems. Diffusion coefficients were obtained to estimate the mobility of the components and the stability of the molecular associations. It has been concluded that the molecular mechanism of the initial stages of the sol/gel process used for preparation of the organic/inorganic hybrids involves clustering of the organofunctionalysed inorganic components as a first step and then progressive hydrolysis as consequent steps. The organic polymer component plays a role of the cluster "wrap" and thus prevents the particles from unlimited growth and precipitation from the solution.