Cellular patterns in organic-inorganic hybrid film

The formation of cellular patterns, known as "Benard cell", was investigate d in organic-inorganic hybrid films under various conditions. The cells wer e observed in undoped-hybrid films, and its origin was attributed to the co nvection of TiO2 nanoparticles formed in the aging process of the sol. Thes e cells showed the particular properties such as the difference between the center and its surrounding: the center showed a lower refractive index tha n that of the surrounding, a valley at the center with mountain-like surrou ndings, and a hydrophobic center and hydrophilic surrounding. How the cell patterns were formed depended on the conditions such as the atmospheric hum idity and the gravity. It should be also noted that the cells on a silica g lass substrate remained after 1000 degreesC heating.