Rapid Photothermal Healing of Vitrimer Nanocomposites Activated by Gold-Nanoparticle-Coated Graphene Nanoplatelets

Abstract

Vitrimers, an emerging class of polymer materials, are thermosets with dynamic covalent cross-linkers, allowing for topology rearrangement at elevated temperatures. However, vitrimers have several drawbacks, such as slow response times and often lack photothermal catalytic activity. Herein, we demonstrate that embedding functional nanofillers, i.e., hierarchically assembled plasmonic gold nanoparticles (AuNPs) on graphene nanoplatelets (GNPIs) into a vitrimer matrix, induces an ultrafast photothermal healing response. Unlike previous research that mainly focused on bulk materials, our exploration of vitrimer nanocomposite films uncovers unique advantages, such as optical transparency in the visible wavelength, flexibility, and ultrafast localized healing upon exposure to a 532 nm wavelength laser. These remarkable properties of vitrimer nanocomposite films were demonstrated with three various filler compositions and concentrations, where AuNPs/GNPls serve as a powerful filler. Photothermally activated self-healing of these hybrid materials is demonstrated by taking advantage of the localized surface plasmon resonance (LSPR) of AuNPs and the broad absorbance wavelength and high thermal conductivity of GNPls. Furthermore, profilometry is utilized to quantify the volume percent recovery of healing, providing quantitative evidence of increased healing with a higher filler concentration and laser dosage. This localized, ultrafast healing is pivotal for future coating applications, where bulk heating could lead to undesirable deformations. Our comprehensive understanding of the role of filler composition, filler concentration, and laser dosage in the self-healing properties of films opens up a wide array of potential applications for these light-responsive functional materials. The potential applications of these materials span from self-healing coatings to flexible electronics, inspiring a new era of innovative solutions.