Hydroxyethylmethacrylate (HEMA) monomer in different contents was used in the preparation of transparent organic-inorganic hybrid sol-gel matrices. The matrices were studied by analytical techniques before and after irradiation. An increase in the homogeneity of the composite material after the irradiation of HEMA, and a chemical linkage of the monomer with the surface has been observed. Photopolymerization processes were studied by differential scanning calorimetry (DSC). Details of the irradiation times, polymerization rates, and DSC related parameters of HEMA in the sol-gel matrices are reported.