High Efficiency Electrothermal Graphene/Tourmaline Composite Fabric Joule Heater with Durable Abrasion Resistance via a Spray Coating Route

Durable abrasion resistance is the critical capability for the functional textile via coating treatment routes. Here, an abrasion resistant fabric-based Joule heater with sandwich structure was fabricated via spraying in sequence of water-soluble polyurethane (WPU), then composite ink of graphene, WPU and tourmaline, and at last WPU. The composite fabrics with the incorporation of tourmaline exhibited favorable electrothermal performance, which could achieve a steady-state temperature of 75.4 °C in 30 s under 10 V voltage, and possessed a high power density (2 × 103 W/m2). The flexible heater exhibited remarkable abrasion shielding performance, only resulting in 21.1% electrical conductivity reduction after a 2500-cycles abrasion test, far less than the 87.0% of fabrics without a sandwich structure. The application on thermal therapy of the hand exhibited 1.8 °C rise of blood vessel around the heater under 8 V voltage. Therefore, the as-obtained Joule heater can be widely applied in functional protective garments and medical electro-heating wearable devices.