Multifunctional superamphiphobic cotton fabrics are in high demand. However, the preparation of such fabrics is often tricky or complicated. Scientists at the Wuhan University of Technology have developed a one-step method to make cotton impermeable to water and oil. The material stays afloat with up to 35 times its weight because of air pockets. These features make this material suitable to make life jackets and swimsuits. Methods currently used to make cotton fluid repellent are time-consuming.
Waterproof and oil-proof fabrics demand recreational water activities because of their low drag and self-cleaning properties. Moreover, while cotton is a popular fabric, it is hydrophilic, so most liquids and dirt can easily mess it up. To improve cotton’s impermeability, previous researchers developed superamphiphobic coatings that were extremely water- and oil-repellant. However, because they required multiple time-consuming steps to apply, these coatings were impractical for large-scale manufacturing. Now, the scientists have done it in one step.
The researchers optimized a one-step process for a liquid-proof coating by mixing dopamine hydrochloride, 3 aminopropyltriethoxysilane, and 1H,1H,2H,2H-perfluorodecyltriethoxysilane with a piece of cotton fabric for 24 hours. The three-part solution developed into a uniform, dark brown coating on the fabric. In tests, the treated cotton was impervious to many common liquids. The new solution also coated inner cotton fibers, making them liquid-proof, too. In other tests, only strong acid and repeated washings reduced the material’s water and oil resistance, respectively.
