A low cost paper tissue-based PDMS/SiO₂ composite for both high efficient oil absorption and water-in-oil emulsion separation

The pollution of water resource and shortage of clean water have become increasingly severe, developing an urgent demand of reliable, efficient yet low-cost material for everyday water purification. In the present work, a superhydrophobic paper tissue-based SiO₂/PDMS composite has been prepared for both oil absorption and water-in-oil emulsion separation. The fabrication process is quite simple since it takes the full advantage of tissue that has naturally strong capillary force of which allows the material to absorb oil from water much more rapidly and completely (>99.9%) even under harsh conditions. The study has shown the novel material is exceptionally efficient in separating water-in-oil emulsion under gravity but no need of extraneous pressure. A variety of emulsions has been proven with high flux (>2,000 L m⁻² h⁻¹) and high separation efficiency (>99.4%). It is believed that this study has proposed a highly reliable and efficient, low cost strategy in both oil absorption and water purification, which shed light on water treatment of both civil use and industry.