Chinese Develop New Waterproof Cotton Fabric

(Agricultural Research Service, USDA)

Scientists with the Shanghai Institute of Applied Physics and the Graduate University of Chinese Academy of Sciences in Beijing have developed a waterproof cotton fabric that continues to repel water after 250 commercial launderings.

The new fabric, say the researchers, looks almost identical to ordinary cotton, is both impermeable and breathable, and retains its super-hydrophobic (waterproof) properties even after being laundered many times. Most waterproof fabrics don’t stay that way after being washed a few times.

The new fabric was made by grafting a commercially available fluorinated acrylate monomer — atom or small molecule that combines or reacts with other small molecules to become polymers — onto bundles of cotton fibers which were irradiated with gamma rays to induce polymerization. The cotton forms covalent bonds with the polymer, rather than coating the cotton as normally done with most waterproof fabrics. The polymer prevents water from adhering to the cotton surface and the water instead forms droplets that roll off the fabric, taking any dust or surface dirt with them.

The researchers tested the fabric in 50 accelerated washings in different detergents, and even adding stainless steel balls to simulate the punishment equivalent to 250 commercial launderings. The researchers say the new fabric retained its super-hydrophobic properties after these tests. The binding of the polymer enables the cotton to maintain its breathability and comfort, which the fabric also maintained after repeated washings.

The authors published their findings in the journal Advanced Materials (paid subscription required).

Hat tip: PhysOrg