Preparation of highly hydrophobic sepiolite for efficient oil removal

Oil spill cleanup has aroused increasing concern in environmental protection, which makes the development of a low-cost absorbent with good hydrophobicity to be a task of high practical significance. In this work, a novel and highly hydrophobic absorbent based on natural clay minerals was prepared and used for oil removal from water. The originally hydrophilic sepiolite was modified by tetraethyl orthosilicate (TEOS) and hexadecyltrimethoxysilane (HDTMS) through a one-pot direct modification. The pristine and modified sepiolite (MS) were characterized for hydrophobicity, morphology, and composition. The results showed that the modify agent was successfully grafted onto the sepiolite surface, improved the roughness and disaggregation of fibers. And MS exhibited higher contact angle compared to the pristine sample. The diesel oil removal efficiency of MS was significantly higher compared to pristine sepiolite. The surface roughness and high hydrophobic properties played important role in the retention of oil from water. This study presented a facile method to produce promising absorbent based on clay minerals with excellent properties for oil spill cleanup.