SiO2 modified superwetting cotton fabric with anti-crude oil fouling, mechanical stability and corrosion resistance

Abstract

A superwetting SiO2/PDA/CF membrane was simply fabricated by modifying cotton fabric (CF) with SiO2 and polydopamine (PDA), which exhibits superoleophobicity (i.e., an underwater oil contact angle (UOCA) is 159.7°), and was characterized by TG, SEM, EDS and FTIR. The oil/water separation performance, mechanical stability and corrosion resistance of SiO2/PDA/CF were investigated. The results show that the water fluxes are 34000 and 31300 L·m−2·h−1 for “crude oil/water” and “toluene/water”, respectively. And the oil/water separation efficiencies all are more than 99%. Continuous separation of “crude oil/water” and “toluene/water” for 15 and 100 times, the separation efficiencies are more than 98% and 99%, and the fluxes decrease by 2.9% and 19.7%, respectively. The membrane shows ultra-low adhesion towards crude oil. The as-prepared SiO2/PDA/CF maintains underwater superoleophobicity (i.e., UOCA>150°) after ultrasonically treating for 9 h or 240# sandpaper abrasion for 500 cycles or after exposure to harsh conditions of saturated NaCl, 1 M H2SO4, 1 M NaOH, respectively for 31 days. SiO2/PDA/CF, which is low-cost and environmentally friendly, has good oil/water separation performance, anti-oil fouling, low oil adhesion, mechanical stability, and corrosion resistance, exhibiting great potential applications in solving the serious problem of oily industrial wastewater and oil spills in the ocean.