Spraying-induced growth of CaCO for the modification of membranes for oil/water separation

Here, a simple spraying-induced in situ growth of inorganic particles strategy was adopted to fabricate composite membranes. Sodium alginate was first sprayed on a polyvinylidene fluoride membrane to provide active sites, and subsequently, alternate spraying of Ca 2+ and CO 3 2− induced in situ growth of CaCO 3 particles to construct hierarchical structures. The optimal membrane exhibited superhydrophilicity/underwater superoleophobicity. The membrane has good oil-water separation efficiency (>99%) and high flux (>2238 L m −2 h −1 ) for several oil-water emulsions. Importantly, the membrane retained acceptable separation performance even after 10 cycles, proving its good mechanical stability and anti-fouling features. The current work may open up a new avenue for the large-scale fabrication of super-wetting membranes for oily wastewater remediation. A simple spraying-induced in situ growth of inorganic particles was proposed for the first time and a PVDF@SA@CaCO 3 membrane was successfully constructed for efficient oil/water separation.