Fabrication of self-assembled hydrophobic fluorinated silica particulate film

Hydrophobic fluorinated particulate films were fabricated by coupling Langmuir-Blodgett silica (LB-SiO 2 ) particulate monolayers with fluoroacrylate polymer, and the depth distributions of chemical compositions were studied. The resultant fluorinated particulate films show surface hydrophobic property with water contact angles (WCA) of 123° (300 nm) and 125° (550 nm), which is dominated in Wenzel wetting state. The surface F/C ratio is only 0.09 at 20°, which is slightly higher than 0.07 at 60°. Fitting results of C1s and O1s high-resolution spectra at 20° and 60° indicate the outmost surface is mainly occupied by fluoroacrylate polymer main chains and the ester side chains stretch toward inner surface and thus hydrophobic fluorinated groups in self-assembled fluoroacrylate film cannot efficiently segregate to the outer surface, which results in low surface F/C ratio and surface WCA.