Facile stearoyl chloride grafted cotton filter fabric and its application in oil-water separation

Chemical graft technology has been arisen widely interesting for its stronger chemical interaction between hydrophobic layers and substrates. Instead of coating technology based on physical function, chemical graft technology can produce hydrophobic membrane with more efficient durability for oil-water separation, which is essential in various industries like sewage treatment and oil spill. As cellulose-based material, cotton filter fabric is a flexible and degradable material with abundant hydroxyl groups, providing great possibility for graft reactions. Stearyl chloride has both hydrophobic alkyl chain and active acyl group, making it easily to be grafted onto cotton filter fabrics. Therefore, we propose to use stearyl chloride as hydrophobic layer and one-step modify cotton filter fabric. The obtained hydrophobic modified cotton filter fabric exhibits high contact angles (CA max = 147 o , CA avg = 141.8 o ), which only decrease slightly after 5 h droplet holding time (CA max = 141 o , CA avg = 126.3 o ). Besides, the modified sample also shows hydrophobic durability after three times gravity-drove oil-water filtration separation (CA max = 137 o , CA avg = 132.6 o ). This hydrophobic modified cotton filter fabric may have potential application in future oil-water separation and the stearyl chloride graft technology is an both effective and efficient way in hydrophobic modification.