日本ゼオライト学会　刊行物 Publication of Japan Zeolite Association

Mesoporous silica nanoparticles (MSNs) are promising as nanofillers with low dielectric constant and low refractive index. For their applications in electronics and optics, preparation of MSNs with high dispersibility and high chemical stability is essential. Here we report the preparation of the stable dispersion of organically-modified MSNs in alcohol solvents, and demonstrate the fabrication of MSNs-silica nanocomposite film applicable as antireflective (AR) coatings. Direct trimethylsilylation of mesostructured silica-surfactant composites nanoparticles (SSNs) by treating with hexamethyldisiloxane under acidic conditions enables us to impart high stability and dispersibility to the nanoparticles as well as to achieve surfactant removal and facile particle recovery. The resulting TMS-MSNs have 2D hexagonal structure and their pore sizes and pore volumes are increased by adding 1,3,5-trimethylbenzene during the synthesis. Nanocomposite films prepared from the mixture of TMS-MSNs and siloxane oligomers exhibit lower reflectivity than a silica film without TMS-MSNs, and the relative reflectivity is decreased with increasing the amount or the pore volume of TMS-MSNs embedded in the films. It is thus demonstrated that TMS-MSNs are useful as nanofillers for fabricating functional nanocoatings.