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For some time, it has been predicted by some in the smart textile industry that a single garment will be able to adapt to changing conditions and needs, keeping its wearer cool what it’s hot outside, and warm when the weather turns chilly. In addition to wearing it outdoors, such clothing could also be worn indoors, drastically reducing the need for air conditioning or heat. That day is fast approaching.
Reporting in ACS Applied Materials & Interfaces, a research team says they have made a strong, comfortable fabric that heats and cools skin, with no energy input. Smart textiles that can warm or cool the wearer are not new, but a single fabric that can do both is. Lead on the project, Guangming Tao, and colleagues wanted to develop a more practical textile for personal thermal management that could overcome previous limitations of bulk, expense and other issues.
The researchers freeze-spun silk and chitosan, a material from the hard, outer skeleton of shellfish, into colored fibers with porous microstructures. They filled the pores with polyethylene glycol (PEG), a phase-changing polymer that absorbs and releases thermal energy. Then, they coated the threads with polydimethylsiloxane to keep the liquid PEG from leaking out. The resulting fibers were strong, flexible and water-repellent. To test the fibers, the researchers wove them into a patch of fabric that they put into a polyester glove.
When a person wearing the glove placed their hand in a hot chamber (122 F), the solid PEG absorbed heat from the environment, melting into a liquid and cooling the skin under the patch. Then, when the gloved hand moved to a cold (50 F) chamber, the PEG solidified, releasing heat and warming the skin. The process for making the fabric is compatible with the existing textile industry and could be scaled up for mass production, the researchers report.
Story Source: Materials provided by American Chemical Society.
Journal Reference: Jiawei Wu, Run Hu, Shaoning Zeng, Wang Xi, Shiyao Huang, Junhui Deng, Guangming Tao. Flexible and Robust Biomaterial Microstructured Colored Textiles for Personal Thermoregulation. ACS Applied Materials & Interfaces, 2020; DOI: 10.1021/acsami.0c02300