An Intelligent Superhydrophilic/Underwater Superoleophobic Temperature Sensitive Switch Device with Excellent Targeted Oil-Water Separation Performance

Abstract Oil/water separation has become a global challenge as more and more oily wastewater is generated from oil spills and industrial wastewater. Super-wetting fuctional materials in oil-water separation has obvious advantages such as high efficiency, simple craft and potential to intelligentialize. But traditional superhydrophobic/superlipophilic oil-water separation material is easily blocked and damaged by oil. Here, a temperature-sensitive superhydrophilic/underwater superoleophobic switch device (TS-PNIPAM-Ni) was prepared using a poly-N-isopropylacrylamide (PNIPAM) hydrogel and magnetic hydrophobic foamed nickel through a one-step solution dipping method. The separation efficiency of TS-PNIPAM-Ni to dichloroethane-water can reach up to 100% and maintain a separation efficiency of more than 99.9% after the completion of 10 separation cycles, and the oil-water separation stops above 34 °C and captures water droplets intelligently. The micro-morphology, micro-structure and components of TS-PNIPAM-Ni and PNIPAM were analyzed with FTIR, SEM and EDS. The TS-PNIPAM-Ni shows excellent superhydrophilic/underwater superoleophobicity, good temperature sensitivity and magnetic navigation function.