The effect of solvent compatibilization in nanocomposite materials

The ability to control the phase separation in sol-gel derived silica/siloxane nanocomposites allows the generation of materials with tailored mechanical properties. One factor that seriously affects the phase separation in a system is the miscibility, both initial and over the lifetime of the reaction. We have examined the effect of changing the phase compatibility by adding a variety of organic solvents to the reaction mixture (e.g., tetrahydrofuran, toluene, xylene and 1,2-dimethoxyethane). In addition, we have varied the amount of solvent added to the system. The microstructure of the phase separation has been analyzed using Scanning Electron Microscopy (SEM) and Small Angle Neutron, X-ray and Light Scattering (SANS, SAXS and SALS). We have investigated the effect the phase separation changes have on the mechanical properties of the resulting materials by looking at the tensile strength, durometer and elongation properties. Findings from this investigation will be reviewed.