Special wettable cotton-containing hybrid composite for heavy oil absorption and light oil resistance in underwater atmosphere

Abstract

By utilizing the gel reaction between dipentaerythritol penta-/hexa-acrylate (5Acl) and branched polyethylenimine (BPEI), the self-made carboxymethylated cotton fibers, chitosan (CTS), and calcium chloride (CaCl2) were simply blended in this reacting system, then only depending on gelation at room temperature, the special wettable cotton-containing hybrid composite was constructed, meanwhile dispensing with any reactive activator. When ambient atmosphere was in underwater condition, heavy oil absorption and light oil resistance of the water-wetted cotton-containing hybrid composite was displayed in the water environment, and which was radically different from the majority of the currently found superwetting phenomena. Based on this, the removal of subaqueous heavy oil was carried out by using this composite product, simultaneously getting rid of water under light oil was also implemented via its water-pretreated state, therefore by just prewetting the mentioned composite, or not, in water, the selective separation for immiscible oil-water mixture could be successfully realized, whether in oil-removing or water-removing filtering separation, its fluxes and efficiencies were higher than 3500 L/m2·h and 96%; from the perspective of difficult or easy degree of such application implementation, simpleness, easiness, adaptability and reliability for the special wettable cotton-containing hybrid composite had advantage over in selective oil-water separation. Beyond that, this unique composite also had a satisfactory capacity to separate of oil-in-water emulsion (flux: 4229.93 L/m2·h, efficiency: 99.71%).