Robust superhydrophobic and superoleophilic filter paper via atom transfer radical polymerization for oil/water separation

Robust superhydrophobic and superoleophilic cellulose-g-PFOEMA filter paper membranes were fabricated via surface grafting of poly(perfluorooctylethyl methacrylate) (PFOEMA) using atom transfer radical polymerization (ATRP). The surface chemical compositions, morphologies and wettability of cellulose-g-PFOEMA with different degree of graft ratio (DG) were investigated using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and contact angle (CA) measurement. IR and XPS showed that PFOEMA were introduced into surface of filter paper. The superhydrophobicity of filter paper increased with amount of PFOEMA grafted. When DG of grafted PFOEMA was higher than 11.2%, the superhydrophobicity reached a steady state and the measured water contact angle was about 157 degrees. The PFOEMA-grafted filter paper exhibited excellent chemical resistance toward a wide range of pH solution from 1 to 12. Cellulose-g-PFOEMA is convenient for oil/water separation with efficiency higher than 95%. The excellent reusability and stability make cellulose-g-PFOEMA filter paper membrane a promising candidate in the applications of oil spillage cleanup and the separation of oil/water mixture.