Wool Can Be Cool: Water‐Actuating Woolen Knitwear for Both Hot and Cold

• Published in: Advanced functional materials Vol. 30; no. 51
• Main Authors: Hu, Jinlian, Irfan Iqbal, Mohammad, Sun, Fengxin
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01-12-2020
• Subjects: adaptive textiles; all‐weather woolen knitwear; Body temperature; Knitwear; Materials science; Protective clothing; shape memory; Shivering; thermal management; water‐actuating wool; Weather
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202005033

As a second skin of the human body, clothing offers protection and aesthetic qualities. Because of the inability of materials to adapt to different weather conditions, different clothing is required for different seasons, namely, thin and open garments for summer, thick and closed ones for winter. Moreover, the body maintains its internal core temperature (37 °C) through sweating and shivering. Herein it is reported that woolen knitwear can provide not only warmth, but also a cooling sensation when a body sweats. The fascinating water‐responsive switching (opening/closing) of the knit pores keeps the skin dry, thus helping to maintain a constant body temperature, providing comfort and safety.
Water‐actuating all‐weather woolen knitwear is demonstrated here for thermoregulation by utilizing the shape memory effect of pure descaled wool. The studied woolen knitwear provides a cooling sensation during sweating and warmth when the skin is dry. This work shows significant potential to rediscover natural fibers as smart materials.