Agriculture & Climate Change, Canada (Commonwealth Union) – Microplastics are the tinier components of macro plastics which has a significant impact on atmospheric pollution as they can enter the food chain via ingestion by fish in oceans and rivers and by animals on land. The excessive use of plastic has been blamed for much of these woes, with researchers focusing on a variety of fields to help tackle the negative effects of microplastics from Artificial Intelligence to nanotechnology.
Researchers from the University of Toronto (U of T) have formed a remedy to lower the amount of microplastic fibres shed while washing synthetic fabrics.
The global fashion industry is said to be responsible for the formation of large numbers of cheaply made clothing with a high impact on the atmosphere, where over 2 thirds of clothes are currently produced with synthetic fabrics, like nylon, polyester, acrylic and rayon, according to researchers.
When clothes produced from synthetic fabrics are placed into the washing machine, the friction resulting from cleaning cycles forms tiny tears leading to microplastic fibres. These measure under 500 micrometres in length, to break off and move into the laundry drains that end up in waterways. Once it enters the waterways it is hard to remove the particles and they may take many years to degrade.
U of T researchers however may have a solution as they have indicated that the slippery solution to this issue may be a silicon-based organic polymer coating available in plenty of household products.
Kevin Golovin, who is an assistant professor of mechanical and industrial engineering in the Faculty of Applied Science & Engineering, and his team have formed a 2-layer coating produced from polydimethylsiloxane (PDMS) brushes, which are linear, single polymer chains grown from a substrate producing a nanoscale surface layer.
Research done by the team has demonstrated that this coating is capable of significantly lowering microfibre shedding of nylon clothing after repeated laundering, according to findings that appeared in Nature Sustainability.
“My lab has been working with this coating on other surfaces, including glass and metals, for a few years now,” said Golovin. “One of the properties we have observed is that it is quite slippery, meaning it has very low friction.”
PDMS is utilized in shampoos to produce hair shiny and slippery, and is further present in food as an additive in oils to block liquid foaming as they are bottled.
Sudip Kumar Lahiri, who is a post-doctoral researcher in Golovin’s lab and lead author of the study, made the case that lowering the friction that takes place while wash cycles with a PDMS-based fabric finish that may block fibres from rubbing together and disconnecting when in the washing machine.
A key obstacle the researchers were impacted by during their research was ensuring the PDMS brushes remained on the fabric. Lahiri, a textile engineer by trade, formed a molecular primer based on his knowledge of fabric dyes.
Lahiri worked out the type of bonding required for keeping dyed apparel colorful following repeated washes that would also work for the PDMS coating.
Both the primer nor the PDMS brushes work separately to lower the shedding of microplastic-fibre. However together, they form a tough finish that lowered microfibres release by over 90% following 9 washes.
“PDMS brushes are environmentally friendly because they are not derived from petroleum like many polymers used today,” explained Golovin, who was also awarded the Connaught New Researcher award for the research.
“With the addition of Sudip’s primer, our coating is robust enough to remain on the garment and continue to reduce micro-fibre shedding over time.”
As PDMS is naturally a water-repellent material, the scientists are presently conducting research on making the coating hydrophilic making coated fabrics with an improved ability to wick away sweat. The team has gone further with their work beyond nylon fabrics.