Scalable preparation of MWCNTs/PAN conductive composite fibers with Tai Chi structure for thermotherapy textiles

Compared with traditional clothing, wearable textiles with physiotherapy were a breakthrough innovation, among which fiber materials with good mechanical properties and excellent electrical conductivity were key. Herein, we prepared profiled conductive composite fibers (PCFs) with Tai Chi structure based on the polyacrylonitrile (PAN) and carboxylic multiwall carbon nanotubes (MWCNTs) by wet spinning, achieving the synchronous improvement of mechanical and conductivity under a small quantity of conductive fillers doped. By changing the angle of spinning, the migration of MWCNTs could be induced and controlled, realizing the preparation of Tai Chi structure. The PAN and MWCNTs were enriched into the axial unilateral of fibers respectively, similar to the Tai Chi structure, when the spinning angle was 30°. The special Tai Chi structure could concentrate carriers to form a continuous and interpenetrating conductive path and retained the good flexibility and tensile strength of composite fibers. The PCFs prepared with 6 wt% MWCNTs loading possessed 51.6 S/cm and 291 MPa. The wearable electric heaters prepared by PCFs could get a comfortable temperature (30 °C ∼ 60 °C) under the safe voltage condition and had good repeatability and stability, which was expected to provide valuable reference for the development of thermotherapy textiles.