Rapid and Local Self-Healing Ability of Polyurethane Nanocomposites Using Photothermal Polydopamine-Coated Graphene Oxide Triggered by Near-Infrared Laser.

Yu-Mi Ha,Yong Chae Jung,Young Nam Kim

doi:10.3390/polym13081274

Abstract

In this study, we report the self-healing ability of polyurethane (PU) nanocomposites based on the photothermal effect of polydopamine-coated graphene oxide (PDA–rGO). Polydopamine (PDA) was coated on the graphene oxide (GO) surface, while simultaneously reducing GO by the oxidation of dopamine hydrochloride in an alkaline aqueous solution. The PDA–rGO was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy–energy-dispersive X-ray analysis. PDA–rGO/PU nanocomposites with nanofiller contents of 0.1, 0.5 and 1 wt% were prepared by ex situ mixing method. The photothermal effect of the PDA–rGO in the PU matrix was investigated at 0.1 W/cm2 using an 808 nm near-infrared (NIR) laser. The photothermal properties of the PDA–rGO/PU nanocomposites were superior to those of the GO/PU nanocomposites, owing to an increase in the local surface plasmon resonance effect by coating with PDA. Subsequently, the self-healing efficiency was confirmed by recovering the tensile stress of the damaged nanocomposites using the thermal energy generated by the NIR laser.

Highlights

Self-healing materials possess the inherent ability to recover from damage, maintaining their function and structure
PDA–rGO was synthesized via oxidation polymerization using dopamine hydrochloride [28,29]
This was because the catechol groups in DA were oxidized to quinone groups; these combined with OH on the surface or edge of graphene oxide (GO), resulting in PDA–rGO [30]

Summary

Introduction

Self-healing materials possess the inherent ability to recover from damage, maintaining their function and structure. Self-healing is initiated by molecular diffusion, contact of failure surfaces, dynamic bonding, and the formation of interactions [2,3]. To recover the shape and heal the damaged parts, materials are needed as an energy source to facilitate molecular diffusion. Many self-healing methods rely on energy sources, such as heat [4], light [5], and electricity [6]. Most studies have focused on self-healing systems with thermal energy as the fundamental energy source; thermal energy can repair damaged polymers [7,8]. Thermal energy can affect the undamaged parts of the polymers, which can cause dissociation of the dynamic bond network. The material properties deteriorate due to heating, which may negatively impact the quality of the products

Methods

Results

Conclusion