Preparation of super-hydrophobic film with fluorinated-copolymer

Organic superhydrophobic films were prepared by utilizing TA-N fluoroalkylate (TAN) and methyl methacrylate (MMA) copolymer as water-repellent materials and inorganic silica powder as surface roughness material has been developed. Coating solutions prepared by adding silica powders into copolymer solution directly (one-step method) and by adding silica powders into monomers and allowing them to react (two-step method). The results showed that contact angles of the films prepared by one-step method (37.6 wt % of silica powders in the coating solution) were greater than 150 degrees, but the transmittance of the film at visible light was only 30%. On the other hand, the contact angle of films prepared by two-step method (20 wt % of silica powders in the coating solution) was greater than 160 degrees and the transmittance of the film was greater than 90%. The contact angle of the film prepared by poly(octyl acrylate), POA, was 32.1 degrees, but while introducing silica powder into the system, the contact angle of the film was reduced to be smaller than 5 degrees. Thus, superhydrophobic and superhydrophilic films can be obtained by introducing a roughening material on the hydrophobic surface and the hydrophilic surface, respectively. (c) 2007 Wiley Periodicals, Inc.