(256e) Synthesis and Application of Organically-Modified Mesoporous Silica Nanoparticles for Anti-Reflective Coatings

Mesoporous silica has attracted significant interest for its low dielectric constant (low-k) and low refractive index (low-n). Two approaches are practically available to fabricate these materials in the form of thin films; one is the direct formation of mesoporous silica films, e.g., by evaporation-induced self-assembly process, and the other is the formation of nanocomposite films where mesoporous silica nanoparticles (MSNs) are embedded in polymer matrices. The latter has the advantages that deterioration of the film and/or the substrate upon surfactant removal can be avoided because MSNs are prepared prior to the film formation, and therefore various matrix polymers and substrates including thermally or chemically less stable ones are available. For such applications of MSNs, removal of the surfactants from the mesostructured silica?surfactant composite nanoparticles (SSNs) is required, without the loss of the monodispersity and the internal mesostructure. Here we report the preparation of a stable dispersion of organically-modified MSNs in alcohols by simultaneous trimethylsilylation and surfactant removal as well as particle recovery, and demonstrate that these nanoparticles can be used for the fabrication of low-n films where the nanoparticles are well-dispersed in a silica matrix. These nanocomposite films have remarkable anti-reflective (AR) property that is applicable to high-performance AR coatings used in optical display devices [1].

References [1] Y. Hoshikawa, H. Yabe, A. Nomura, T. Yamaki, A. Shimojima, and T. Okubo, Chem. Mater., 22 (1), 12-14 (2010).