Polyurethane Blended with Silica-Nanoparticle-Modified Graphene as a Flexible and Superhydrophobic Conductive Coating with a Self-Healing Ability for Sensing Applications

The introduction of self-healing ability into conductive materials has been the subject of great concern in recent years. In this work, a flexible and superhydrophobic nanocomposite coating with intrinsic and superficial dual self-healing ability was prepared. The fabric coating is empowered with the intrinsic self-healing ability that is performed by the disulfide bonds in the main chains of polyurethane (PU) as well as the multiple hydrogen bonds between silica-nanoparticle-modified graphene and PU. Meanwhile, the hydrophobic long chains in the side chains of PU can migrate on the surface to repair the superficial damaged parts of the coating. Owing to the integration of silica-nanoparticle-modified graphene and self-healing PU, the obtained multifunctional flexible coating not only shows excellent piezoresistive sensing performance but also exhibits superhydrophobic ability. This self-healing multifunctional flexible coating has potential applications in the fields of antistatic electricity, wearable electronics, battery, electromagnetic shielding, and so on.