Aqueous Nanocoating Approach to Strong Natural Microfibers with Tunable Electrical Conductivity for Wearable Electronic Textiles

Electronically conductive and mechanically strong natural fibers with desirable durability, flexibility, and environmental compatibility are in great need for manufacturing multifunctional textiles. Here we reveal a facile yet effective nanocoating approach to immobilization of few-layer graphene oxide (GO) nanosheets at ramie fiber by hydrogen-bond-driven self-assembly process under all-aqueous and additive-free condition. The surface morphology and chemistry of GO-functionalized ramie fiber (GOFR) were significantly altered with the homogeneous decoration of trace amount of GO nanosheets, readying remarkable property improvements and functionality realization. The tensile strength of GOFR (553 MPa) witnessed an increase of over 25% compared to pristine ramie, as accompanied by moderate promotion of extensibility with the assistance of robust GO nanosheets. It is worth noting that exceptionally high electrical conductivity was achieved for thermally reduced GOFR (rGOFR), with values as high as 83.2 S/cm after reduction at 250 °C for only 30 min. By tuning the reduction time and temperature, the conductivity of rGOFR was well controlled in an extremely wide range of 0.1–83.2 S/cm. This effort provides useful insights into the fabrication of highly strong and conductive natural fibers in the promising field of smart fabrics integrating high strength, flexibility, intelligent functionality, and environmental compatibility.