Cationic guar gum-kaolin coated combined superhydrophilic and oleophobic nylon textile for efficient oil separation from wastewater

The treatment of wastewater polluted by oils and organic solvents has becoming a global environmental issue. Superhydrophobic separation materials have been widely developed to solve the problems, these materials are easily fouled by high viscosity oil fouling, causing the decrease of separation efficiency. Developing the materials with high hydrophilicity and oleophobicity in air via a facile and inexpensive approach is vital to address the oily water problems. Herein, a guar hydroxypropyltrimonium chloride-perfluorononanoate/kaolin (GHTC-PFN/KL) coated nylon textile (NT) was fabricated via a facile dip-coating approach. The obtained textiles reveal good superhydrophilicity, high oleophobicity in air, and low oil adhesion. By virtue of their special wettability, the functionalized textiles without any pre-wetting allow water to pass but preventing the passage of oils, which enables the textiles to be utilized for the selective separation to water/oil mixtures. The separation efficiencies for different oils are more than 96.7%. The modified textiles are capable of separating the oils employed with acidic, alkaline, salty solutions and hot water. Especially, a large quantity of water underoil is able to be continuously separated in situ via the multilayered textile tube at vacuum system. Simple preparation steps, scalable process and low cost make the as-prepared textile an ideal candidate for dealing with oily wastewater and purifying water-containing oil.