Eco-friendly construction of oil collector with superhydrophobic coating for efficient oil layer sorption and oil-in-water emulsion separation

In this study, we present an environmentally friendly oil collector for the separation and collection of the oils from water. The collector was designed via the filling of oleophilic-hydrophobic kapok fiber in a superhydrophobic fabric bag. The superhydrophobic fabric was fabricated via a facile, cost-effective, and scalable one-step dipping approach, which possess high oil/water separation efficiency for a series of oil/water mixtures with different volume ratio of oil to water. The as-prepared collector can absorb various oil layers from water into the pores of kapok fiber assembly while repelling water absolutely because of the superhydrophobicity of the fabric. The collector also exhibits high sorption capacity, fast sorption rate, and good recyclability. Furthermore, the oil sorption capability of the collector can be regulated through changing fiber filling density based on actual situation. More importantly, the fabricated collector with high fiber filling density (>0.3 g) can be able to separate oil droplets from oil-in-water emulsion with a separation efficiency of over 98.9%. Therefore, the findings in the present study may offer an environment friendly, inexpensive, and easily-operated approach for the efficient separation of oil layer and oil droplets from water.