Microstructure, Optical, and Dielectric Characterization of Porous Gel Silica Impregnated with PMMA

The microstructure, optical, and dielectric permittivity of gel silica impregnated with polymethyl methacrylate (PMMA) were evaluated. Samples with and without PMMA were compared for pore size reduction and for their dielectric response in the 1–100kHz frequency range. The dielectric constant was as low as 3–5, which is much less than the value for the wet silica gel (150). Besides its insensitivity to the moisture content in the environment, this composite material is much easier to handle and to machine. The discovery of these characteristics points to an opportunity for the application of silica gel–PMMA composites in the optical-electronic field.