Fabrication of segmented cavity films and their application to nanocomposite materials

The fabrication of a novel organic-inorganic nanocomposite film in which functional molecules are incorporated with 2-dimensional (2-D) selectivity is described. The 2-D selectivity is attained by photofabrication of segmented nanocavities which can accommodate organic molecules. A composite thin film of 4-azidobenzoic acid (ABA) and titania (TiO₂) was obtained by the surface sol-gel process of their mixed precursors. UV irradiation of the ABA/TiO₂ film caused decomposition (N₂ gas evolution) of the azide group of ABA, and nanocavities were created within the matrix. The nanocavity can accommodate ABA and sulforhodamine B molecules. 2-D sequential incorporation of these molecules into different film segments was made possible by formation of segmented nanocavities via photodecomposition of ABA through a photomask. The current approach allows incorporation of varied functional molecules into segmented nanocavities. Designed 2-D arrangement of the nanocavity within thin film matrixes would find many novel applications.