Development of durable highly stretchable electrothermal conductive fabrics coated with carbon based fillers

Over the years, researchers have made significant strides to incorporate the conductive materials into textile structures to develop the flexible and electrically conductive fabrics. However, the development of highly stretchable and durable electrothermal conductive fabrics remains a significant challenge. In present research, we introduced a simple and novel approach for the deposition of two types of carbon-based electrothermal conductive materials (carbon nanotubes CNTs and carbon nanoparticles CNPs) over the stretchable knitted fabric structure using solution dip-dry method. The electrical resistivities (surface and volume) as a function of different pH range (2.5 to 6.5) at different number of dipping cycles (1–4) were characterized. The pH 6.5 proved to be best for dispersion and maximum attachment of CNTs and CNPs on the surface of fabrics, showing lowest volume resistivity about 85 Ω·mm CNTs and 212 Ω·mm for CNPs coated fabrics. Secondly, the comparison between volume and surface resistivities at normal condition and at different stretching percentage of fabric was also analysed, where, negligible increase in electrical resistivity values was observed up to 70% stretch. Furthermore, the effect of the applied pH range was justified by Polydispersity Index (PDI), Zeta potential, particle size analysis and Dynamic Light Scattering (DLS). The coated fabrics were assessed for their morphology and geometric characteristics by Scanning Electron Microscopy (SEM), and optical microscopy (OM). The effectiveness of developed electrothermal conductive substrates for electromagnetic shielding was analysed over a frequency range of 30 MHz to 1.5 GHz. The sample produced at higher pH and maximum number of dips exhibited the maximum shielding ability against CNTs and CNPs coated fabric was about 16 dB and 13.5 dB, respectively. Additionally, the thermal properties were also assessed. The fabrics exhibited Ohmic heating range 30°C to 130°C at 10 V in 60 min. Moreover, the noted thermal conductivities were about 1.6 W/mK for CNTs coated fabric and 0.7 W/mK for CNPs coated textile.