Dual-templating synthesis of compressible and superhydrophobic spongy polystyrene for oil capture

Polystyrene is a common material featured with its low cost. In this work, a novel low dense polystyrene sponge with superhydrophobicity and compressibility was prepared successfully by a dual-templating method, including High Internal Phase Emulsions (HIPEs) processing and the introduction of organic template species. For the first time stearic acid or calcium stearate was introduced into the HIPEs system to enhance micro roughness and impart the PolyHIPEs with superhydrophobicity. Besides, owing to the low density, high porosity, interconnected network structure and ultra large void size, the sponge exhibited fast oil adsorption rate and superior oil adsorption capacity of 66.2 g/g toward diesel. After adsorption saturation, the sponge was regenerated by simple squeezing with the deoiling rate over 80%. Importantly, the sponge showed swellable property and about 80% of the initial adsorption capacity was retained after 10 adsorption-compression circles. High adsorption rate, excellent oil adsorption capacity, high selectivity, low cost, compressibility and renewability, all these favourable properties make it an ideal and practical oil adsorbent.