Using silica sol and dopamine as modifiers

SiO2 modified layers were fabricated on the microporous polypropylene membrane (MPPM) surfaces by a one-step reaction. The resulted membranes were characterized with Fourier transform infrared spectroscopy (FTIR)

environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy (EDX). The results confirmed that SiO2 particle was dispersed uniformly on the MPPM surface. The experimental results of water/oil contact angle and water flux indicated that the modified membranes had superhydrophilic and underwater superoleophobicity surface

and showed excellent water permeability with high pure water flux [up to (5100±500) L·m-2·h-1 under 0.1 MPa]. The separation abilities of the modified membranes for oil/water emulsion were also investigated. It was found that the modified membranes could separate oil/water emulsion effectively with a highest water flux of 2830 L·m-2·h-1 and oil rejection ratio of 99.8% under 0.05 MPa. Moreover

oil rejection ratio of the modified membranes could retain above 99% even under 0.15 MPa

and the oil attached to the membrane surfaces could be easily removed by water. The silica-decorated membranes enable an efficient and energy-saving separation for oil/water emulsion

and thus shows attractive potential for practical oil/water emulsion separation.