Improved superhydrophobicity of magnetic melamine sponge by aminosilane for batch and continuous oil–water separation

Abstract

Continuous and efficient separation remains the thorny problem that restricts oil–water separation materials for the large-scale application of oil–water separation. A kind of magnetic melamine sponges with enhanced superhydrophobicity was fabricated by dip coating of polydopamine-modified Fe3O4 nanoparticles, (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (HDTMS) on melamine sponge. The superhydrophobicity of melamine sponge was improved by adding APTES to cover hydrophilic group of polydopamine. The melamine sponge exhibited water contact angle of 158.3°, the absorption capacity of 43.2–80.7 g/g, volume utilization of 0.70–0.97 v/v and separation efficiencies of 99.6 % for oil–water mixture and 98.6 % for oil/water emulsion. The sponge could carried out in batch and continuous filter devices, and repeated oil absorption capacity could achieve 92.8–96.4 % of initial oil absorption capacity after 45 absorbing-squeezing cycles. The above performances of the as-prepared sponge suggest that it is a promising candidate for large-scale application of oil-spill cleanup and oily wastewater treatment.