Near-Infrared-Light-Assisted Self-Healing Graphene-Thermopolyurethane Composite Films

Abstract

Graphene-thermopolyurethane (G-TPU) composite films were fabricated and the effects of the TPU initial concentration, characteristics of TPU, and graphene loading on the electrical, mechanical, thermal, infrared thermal response and near-infrared-light-assisted self-healing properties of the composite films were investigated in detail. The experimental results demonstrate that the comprehensive performances of the composite film are related to the initial concentration of the TPU solution and the characteristics of the TPU and the graphene loading. The composite film prepared from TPU solution with low initial concentration can have conductivity under the condition of low graphene content. However, the composite film prepared with appropriate initial concentration of TPU solution and high graphene loading is conducive to obtain high conductivity. After 60 s of near-infrared illumination, the temperature of the composite film first increases and then decreases with the increase in graphene loading until it reaches saturation. The near-infrared light thermal response of the composite film with high graphene loading is related to the initial concentration of TPU solution, while the near-IR thermal response of the composite film with low graphene loading is independent of the initial concentration of TPU. The surface micro-cracks of the composite film almost disappeared after 10 min of near-infrared illumination. The resistance of the conductive composite film increases after healed. The composite film prepared with low melting point TPU is more favorable to obtain high near-IR thermal self-healing efficiency.

Near-infrared light induced curing of electrically conductive adhesive assisted by upconversion particles

“…Especially for the system containing photothermal fillers (for example, carbon nanotubes and graphene), NIR light could be converted into heat more efficiently. 21–23 Bonardi et al 24 reported the photothermal induced free radical polymerization of (meth)acrylates using graphene as well as carbon nanotubes as NIR light heaters. After 100 s irradiation of NIR light, the system temperature reached more than 100 °C which induced the polymerization of the monomer, and the final double bond conversion rate reached 75%.…”