Preparation of Calcium Stearate-Coated Kapok Fibers for Oil Sorption

Kapok fiber has been known for its hydrophobic-oleophilic characteristics and exhibits a great potential as oil sorbent. Methods in enhancing its hydrophobicity have been explored to improve its sorption performance in oil-in-water applications. This study investigates the oil sorption performance and hydrophobicity of kapok fibers coated with calcium stearate, a known waterproofing agent. The calcium stearate solution was prepared by mixing known amounts of stearic acid and calcium chloride in an ethanol solution. This was followed by hydrolysis using 0.12 M sodium hydroxide solution. The calcium stearate-coated kapok fibers exhibited higher hydrophobicity compared to raw kapok fibers with a water contact angle of ~137°. It achieved the highest oil sorption capacity and reusability of 50 g/g and 65% for viscous motor oil, respectively.