LAUSR

Abstract Maintenance of the layered regularity in organized particle films of fluorinated chain-modified nanodiamond (ND) with excellent heat resistance under heating was investigated. In fluorinated phosphonic acid-modified ND, desorption of the modified-chain by temperature elevation was suppressed up to 300 °C. The fluorinated long-chain phosphonate-modified ND formed a stable single-particle film on the water surface, and the multilayers exhibited high layered regularities. This compound had remarkably improved water repellency on the surface at the level of a single-layer film. However, its heat resistance temperature was less than 100 °C. The layered regularity, which is easily disturbed on heating, was predicted to be caused by multiple defects in the particle packing in the plane. Therefore, during the formation of a monolayer on the surface of the fluorinated long-chain phosphonate-modified ND, compression and expansion were performed multiple times to promote rearrangement of the particles. As a result, the packing density of the particles in the plane and the maintenance of the layered order improved. In comparison, the layered order of stearyl phosphonate-modified ND was maintained up to 175 °C; hence, it was suggested that the packing of the modified-fluorinated chains comprised bidentate bonds and that weak van der Waals interactions were relatively sparse.