Thermo Driven Controllable Emulsion Separation by a Polymer Decorated Membrane with Switchable Wettability.
A thermoresponsive Poly(N isopropylacrylamide) (PNIPAAm) modified nylon membrane was fabricated via hydrothermal route. Combining rough structure, proper pore size, and thermoresponsive wettability, the membrane can separate at least 16 types of stabilized oil in water and water in oil emulsions at different temperatures. Below the LCST (ca. 25 degC) the material exhibits hydrophilicity and underwater superoleophobicity, which can be used for the separation of various kinds of oil in water emulsions. Above the LCST (ca. 45 degC) the membrane shows the opposite property with high hydrophobicity and superoleophilicity, and it can then separate stabilized water in oil emulsions. The material exhibits excellent recyclability and high separation efficiency for various kinds of emulsions and the hydrothermal method is facile and low cost. The membrane shows good potential in real situations such as on demand oil spill cleanup, industrial wastewater treatment, remote operation of oil/water emulsion separation units, and fuel purification.
Angewandte Chemie