Durably Superhydrophobic Cotton Fabric Constructed by Silica Particles and Polydimethylsiloxane via “Mosaic Mode” for Self-Cleaning and Oil–Water Separation

Improving the surface roughness of cotton fabric is one of the main strategies to prepare superhydrophobic cotton fabric. To improve the surface roughness of fabric, it is advisable to immobilize inorganic/organic particles on the surface of cotton fabric. However, the durability of the superhydrophobic cotton fabric is very poor due to the inorganic/organic particles are easily detachable from the fabric surface. In this work, a mild eutectic solvent prepared by choline chloride and oxalic acid was used to etch the cotton fabric, making the surface of the cotton fabric have many ravines. These ravines on the cotton fabric can be used the embedded the silica particles, thus making the silica particles firmly immobilized on the cotton fibers. Then, the treated cotton fabric was coated with polydimethylsiloxane (PDMS). As a result, the water contact angle of the finished fabric was reached at 156.9°. In addition, the superhydrophobic cotton fabric constructed by silica particles and PDMS via “Mosaic Mode” showed excellent mechanical and chemical stability. Therefore, the finished fabric has great potential application in the self-cleaning and oil–water separation fields.