Sawdust-based superhydrophobic pellets for efficient oil-water separation

Abstract

Severe water pollution by means of oil is the major issue worldwide. Emerging materials like superhydrophobic surfaces have shown immense potential to control this issue. Herein we utilized low-cost Sawdust-Polystyrene (SD – PS) composite and developed a facile strategy to prepare a free-standing superhydrophobic pellet for efficient oil-water separation. More importantly, the simple recovery of the absorbed oil is feasible. To achieve crack-free, regular and robust superhydrophobic SD – PS pellet, the concentration of polystyrene, the quantity of sawdust in polymer solution and thickness of the pellet was optimised. The surface morphology analysis confirmed an adequate binding between sawdust and polystyrene in composite structure with formation of micro-voids less than 100 μm that facilitated efficient oil-water separation. The superhydrophobic pellet exhibited oil-water separation efficiency higher than 90% for the oils and organic liquids like hexane, kerosene, diesel and coconut oil with excellent separation cycles around 30. The mechanically durable superhydrophobic SD – PS pellet could separate oil from muddy as well as warm water, which are more suitable for industrial applications.