Microplastics—minuscule plastic particles less than 5 millimeters in length—are continually shedding from our clothes, especially when they’re being laundered. A single routine wash could release 700,000 microplastic fibers, which leak into our waterways, harm wildlife, and end up in our drinking supply (and our bodies).
Researchers in the University of Toronto’s mechanical and industrial engineering department found that as fibers rub against one another and against the sides and drum of the washing machine, tiny tears form, releasing minute plastic particles. This is significant, as an estimated 35% of microplastics in aquatic systems come from washing synthetic clothes.
To counter that, they developed a two-layer nanoscopic silicone coating material. In tests, the coating shielded garments from friction, significantly reducing the shedding of plastics from synthetic materials during wash cycles. The team hopes the product could soon be adopted by the fashion industry, and reports early interest from sustainably minded companies, including Patagonia in the U.S., and Lululemon and Arc’teryx in Canada.
The coating’s first layer is silicone, which has slippery properties that allow fibers to glide past one another, explains Kevin Golovin, an assistant professor and the project’s lead researcher. A second layer was added so that the silicone coating would actually adhere to the garment, using the same principles that permit dyes to cling to textiles. “We call it a primer, like when you’re priming a wall to paint it,” Golovin says.
The testing was admittedly laborious.The team performed actual washes and filtered out material from the water, then students slowly and carefully counted every microfiber under a microscope. They found that the coating reduced microplastic shedding by 93% and remained resilient through different temperatures and cycle durations.
Silicone is a relatively sustainable material, since it’s made from sand, unlike most petroleum-derived plastics. “I wouldn’t say it’s the world’s most environmentally friendly material because it doesn’t degrade,” Golovin says. “But it also is completely chemically inert.” It doesn’t affect the look of the clothing, because the coating is nanoscopic, and breathability tests ensured that it doesn’t clog the pores of the textile.
They did the initial research on nylon clothing, but hope the coating’s properties will extend to all kinds of synthetic materials—from which two-thirds of our clothing is made. Currently they’re looking to prepare a water-absorbent coating for polyester, another common synthetic fabric.
Further studies are focusing on whether the coating would prevent atmospheric shedding, because research has found that microplastics also shed in the air and humans inevitably inhale them.
Although the team hasn’t done an economic analysis, Golovin says silicone finishes already exist, so they are likely economically viable for businesses. Still,for less environmentally motivated companies, more persuasion may be needed. Golovin hopes that if the research continues to be successful, governments could create microplastics regulation mandating that companies use the technology in their garments to help reduce plastic pollution.
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