Researchers developed a non-toxic alternative to water-repellant coatings, according to a report published on July 2, 2018.
This study was conducted by the researchers at Massachusetts Institute of Technology (MIT). They developed a coating that adds water-repellency to natural fabrics and is more effective than the existing coatings. Coatings that are presently being used to make fabrics water repellent consist of long polymers with perfluorinated side-chains, which has many disadvantages.
Therefore, the research combined two things, a shorter-chain polymer that confers some hydrophobic properties and has been enhanced with some extra chemical processing; and a different coating process, called initiated chemical vapor deposition (iCVD). Dan Soto, lead author of the paper, was the one who came up with the best short-chain polymer and made the deposition of polymer with iCVD possible.
Using the iCVD coating process, a very thin, uniform coating was produced that follows the contours of the fibers and does not lead to any clogging of the pores, thus eliminating the need for the second processing stage to reopen the pores. Furthermore, a kind of sandblasting of the surface can be added as an optional process to increase the water repellency.
Then, few tests were conducted using the coated fabrics in the lab. The coated materials have been subjected to repeated washings with no degradation of the coatings, and also have passed severe abrasion tests, with no damage to the coatings after 10,000 repetitions. The research team is planning to continue working on optimizing the chemical formula for the best possible water-repellency.