Low cost fabrication of polypropylene fiber composite membrane with excellent mechanical, superhydrophilic, antifouling and antibacterical properties for effective oil-in-water emulsion separation

In this work, a low cost and flexible composite membrane containing the meltblown and spunbond polypropylene (PP) microfibers was designed and fabricated by means of the hot pressing followed by dip-coating of chitosan solution. We systematically studied the morphological structure, wettability, mechanical property, anti-oil fouling and anti-bacterial performance. The chitosan-modified PP (CS-PP) composite membrane exhibited the superhydrophilicity, underwater superoleophobicity and ultralow oil-adhesion property. Meanwhile, it was found that, solely under the driving of gravity, the water permeation flux of the CS-PP composite membrane was 325, 315, 276 and 265 L.m(-1).h(-1) for the toluene-in-water, n-hexane-in-water, diesel-in-water and vegetable oil-in-water emulsions, respectively, and the separation efficiency was up to 99%. The antibacterial activity could be observed for the CS-PP composite membrane by the inhibition zone testing. In addition, the combination of meltblown and spunbond PP microfiber endowed the composite membrane with excellent tensile strength (up to 6.78 MPa). All these results suggest the CS-PP composite membrane as a promising potential and energy-efficient separation membrane for the treatment of surfactant-stabilized oil-in-water emulsion.