Magnetic polydimethylsiloxane microspheres as hydrophobic collectors for oil removal

Abstract Oil spills represent a significant environmental challenge, requiring materials that are efficient, cost-effective, and reusable for oil–water separation. This study presents a scalable method for fabricating magnetic polydimethylsiloxane (PDMS) microspheres using commercially available oil-based ferrofluid. The choice of ferrofluid simplifies synthesis by providing pre-dispersed superparamagnetic nanoparticles, ensuring compatibility with PDMS. The ferrofluid-PDMS mixture was emulsified in warm water containing a surfactant, stabilizing the microparticles during polymerization. The resulting microspheres were characterized by optical microscopy, and magnetic hysteresis measurements confirm that the microspheres are superparamagnetic. X-ray diffraction confirmed the ferrofluid had magnetite nanoparticles. Oil absorption tests revealed that the microspheres achieved an absorption capacity of up to 580% of their weight. Moreover, the microspheres retained nearly 90% of their original absorption capacity after 10 reuse cycles, demonstrating excellent durability and reusability. This approach combines simplicity, scalability, and cost-efficiency while achieving high performance in oil absorption and magnetic separability. By exploiting the compatibility of ferrofluid and PDMS, the study provides a practical and effective solution for environmental remediation. These microspheres offer an attractive alternative to traditional methods, addressing the need for advanced materials that combine high efficiency with low operational costs and reusability.