Characterization and optimization of robust, highly conductive CNT/PANI composite yarn

Multifunctional carbon nanotube (CNT) yarn possessing exceptional mechanical and electrical properties are highly desirable for smart textile applications but remain challenging to fabricate. In this study, a simple in-situ chemical polymerization approach is proposed to deposit polyaniline (PANI) onto CNT yarn surfaces by precisely controlling the polymerization time. The optimized CNT/PANI composite yarn exhibits significant enhancements, including a 142% increase in tensile strength, more than 120% improvement in Young’s modulus, and a 100% rise in electrical conductivity. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) confirm the successful formation of PANI nanoparticles on the CNT yarn surface, with maximum deposition achieved at a polymerization time of 4 hours (h). Acid-induced densification promotes improved load transfer through a robust PANI network. Notably, the gauge factor (GF) remains largely unchanged, indicating balanced multifunctional performance. This facile strategy provides a promising route for fiber-based electronics and flexible smart textile devices.