Development of a Novel Superhydrophobic Sawdust–Perspex Composite Disc for Efficient Oil–Water Separation

ABSTRACT Water pollution by oil and organic substances causes serious problems that threaten the ecosystem. Superhydrophobic materials represent an effective solution for removing oil from water. The present paper investigates the development of a low‐cost, superhydrophobic composite for oil–water separation. The disc‐shaped composite was prepared by embedding Scots pine sawdust into a Perspex (PMMA) matrix through a simple and convenient procedure. Scanning electron microscopy (SEM) was used to analyze the surface morphology, while the water contact angle was measured using an optical tensiometer to evaluate its wettability. The composite discs were tested for the removal of diesel, engine oil, corn oil, olive oil, and n‐hexane under ambient conditions using a gravity‐driven separation process. Durability and stability were evaluated through tape‐stripping, sandpaper abrasion, and chemical stability tests. SEM images showed a rough and porous surface, which is key to trapping air and achieving the Cassie–Baxter state. The resulting composite discs showed superhydrophobicity with a water contact angle of 151.5° and oil separation efficiency of more than 90%. The composite remained robust throughout 20 cycles of use. A correlation was established to predict the separation rate for oil viscosities ranging from 0.401 to 63.2 cSt. Durability tests showed that the composite disc retained its superhydrophobic behavior even after 100 tape‐peeling cycles and exhibited high hydrophobicity for up to 10 abrasion cycles. The composite disc maintained its superhydrophobic properties within pH range from 2 to 10.1, confirming its chemical stability. These results suggest that the developed sawdust–Perspex composite is a highly effective, sustainable and environmentally friendly option for oil–water separation.