Cotton coated with a new diblock copolymer repels hydrophobic and hydrophilic substances alike; drops of liquid can sit on the surface of the fabric for over a year.
By Tyler Irving
Posted July 2012
Imagine a fabric that could simply shrug off even the worst stains, from red wine to ketchup. That’s exactly what’s been developed by researchers at Queen’s University, who have created a superamphiphobic coating for cotton textiles using a diblock copolymer.
Guojun Liu and Dean Xiong of Queen’s Department of Chemistry are experts in superamphiphobic coatings. In a paper recently published in Langmuir, they describe a diblock copolymer that consists of about 10 units of poly-3-(triisopropyloxysilyl)propyl methacrylate (PIPSMA) and 10 more of poly-2-(perfluorooctyl)ethyl methacrylate (PFOEMA). The PIPSMA block anchors the molecule to hydroxyl groups on the surface of the cotton, while the fluorinated PFOEMA group gives the desired low-energy surface. Experiments showed that the polymers pack very densely on the cotton surface, giving rise to a thick amphiphobic surface that is hard to breach with normal use. The large PIPSMA anchor resists removal during washing.
Liu imagines many commercial applications, from stain repellent lab coats to high-performance swimwear that could cut through the water by trapping a layer of air next to the fabric. If the cost is low enough, the coating could even be added to everyday clothing to prevent stains. “You’re not coating a lot of polymer, so I don’t think it would be too expensive,” says Liu, adding that the processes for making the polymers and coating the cotton are relatively straightforward and amenable to scale-up. Xiong and Liu have filed patent applications internationally and are working with Queen’s’ technology transfer office and an unnamed industrial partner to commercialize the innovation.
Photo credit: Dean Xiong
This video demonstrates how both water and oil-based substances are easily repelled by simple cotton textiles coated with the new diblock copolymer. Such stain-resistant fabrics could be used in high-performance sportswear, military uniforms, and everyday cloating.
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