In Situ-Composing Technique for Durable, Washable, and Anti-abrasive CNT Composite Yarn

To overcome the poor wear resistance and weaving difficulties of carbon nanotube (CNT) yarn, a new type of functional yarn was prepared by a wrapping-melting method. In this method, CNT yarn was wrapped by polypropylene (PP) yarn first, and then a 15 V voltage was applied on both ends of the yarn. The electrically heated CNT yarn melts the wrapped PP yarn and forms a uniformly compacted PP wrapped CNT (PWC) yarn. The study showed that the PWC-15V yarn can retain the good electrical properties of CNT yarn with an electrical conductivity of 4643.7 S/m. Besides, it can work as a multifunctional yarn with strain sensing and electrical heating. As a strain sensor, it has a highest gauge factor of 1.06 and good stability with 100 cyclic loading. As an electrical heater, the PWC yarn can be heated to about 50°C with over 9 V applied voltage. Moreover, the washable PWC yarn also demonstrates good flexibility and improved wear resistance, which indicates that it has great potential for wearable electronics.