Cotton Fabrics Coated with Few-Layer Graphene as Highly Responsive Surface Heaters and Integrated Lightweight Electronic-Textile Circuits

In this work, we describe an eco-friendly and cost-efficient method for the production of highly dispersed few-layer graphene solutions using karaya gum as a bioinspired exfoliating agent. The as-synthesized graphene aqueous solutions can be easily applied on a cotton cloth through dip- or brush-coating, thanks to the interaction between the graphene sheets decorated with the gum and the functional groups on the cotton cloth host substrate surface. The as-prepared fabric composites display high mechanical stability, anchorage, and high electrical conductivity that make them excellent candidates within a relatively high number of technological applications. The study mainly focuses on the potentialities of cotton fabric composites as planar heating devices or electronic-textile (e-textile) circuits prepared by postlaser treatment. By means of a laser beam, local graphitization or partial etching of the graphene conductive lines can be achieved to generate conductive areas with different resistances, which can act as flexible and integrated electronic circuits. Besides lightweight conductive circuits, the graphene-coated cotton fabrics were experimentally tested for other technological applications, that is, as flexible metal-free markers or for IR shielding or as nonflammable barriers for the protection of sensitive devices or to prevent flame spreading. This technology allows one to open a new route toward the development of daily life connected and flexible e-textile devices of added value with low carbon footprint impact.