Facile creation of superoleophobic and superhydrophilic surface by using perfluoropolyether dicarboxylic acid/silica nanocomposites

Perfluoropolyether dicarboxylic acid [HO(O)CCF(CF3){OCF2CF(CF3)}(n)O(CF2)(5)O{CF(CF3)CF2O}(m)?CF(CF3)C(O)OH; n+m=6-12; PFPE-DAcD] was applied to the preparation of PFPE-DAcD/SiO2 nanocomposites by the sol-gel reactions of the corresponding diacid with tetraethoxysilane in the presence of silica nanoparticles under alkaline conditions. PFPE-DAcD/SiO2 nanocomposites thus obtained were found to exhibit a good dispersibility and stability in not only water but also the traditional organic solvents such as methanol, ethanol, 2-propanol, tetrahydrofuran, and 1,2-dichloroethane. Field emission scanning electron micrograph (FE-SEM) and dynamic light-scattering (DLS) measurements show that these fluorinated composites are nanometer size-controlled very fine particles. Dodecane and water contact angle measurements on the modified glass, filter paper, and polyester fabric surfaces treated with these fluorinated nanocomposites were found to exhibit the superoleophobicity and superhydrophilicity. Especially, the modified polyester fabric swatch was applied to the oil/water separation to give the high separation efficiency. Copyright (c) 2015 John Wiley & Sons, Ltd.