Mechanically Robust and Healable Transparent Electrode Fabricated via Vapor-Assisted Solution Process

Abstract

A mechanically robust, transparent, and healable electrode was successfully developed by embedding Ag nanowires (AgNWs) on the surface of polydimethylsiloxane-based polyurethane (PDMS-CPU) cross-linked by Diels-Alder (DA) adducts. The reversibility of the DA reaction enabled the heated dimethylformamide (DMF) vapor to induce de-cross-linking of the PDMS-CPU preformed as a substrate. A combination of the retro-DA reaction and the plasticizer effect softened the polymer surface, embedding the coated AgNWs on the surface of the polymer. With this simple postprocessing, the surface roughness and mechanical stability of the electrode were largely enhanced. Even with a 55 μm bending radius, which corresponds to a strain of 90%, the resistance of the electrode after 10 min of vapor treatment increased by 2.1% for inward bending and 5.3% for outward bending. This result shows a great potential of the proposed method, as it can also be used to fabricate various mechanically deformable transparent electrode. Furthermore, swelling of the PDMS-CPU film owing to the DMF vapor facilitated the healing properties of the scratched electrodes.

Heat‐triggered poly(siloxane‐urethane)s based on disulfide bonds for self‐healing application

“…To obtain the self‐healing silicone, Bao and coworkers developed a polydimethylsiloxane (PDMS) elastomer that possessed high stretchability and autonomous repair ability by metal–ligand bond, and the tensile stress was about 0.25 MPa . Kim and coworkers reported the self‐healing property of PDMS‐crosslinked polyurethane which was crosslinked by Diels–Alder reaction and could be repaired through heated dimethylformamide vapor . In a very recent paper from Xiang et al .…”

Self‐Healing Materials for Next‐Generation Energy Harvesting and Storage Devices

“…Chemical structure of various polymers for the self-healing energy harvesting and storage devices. a) PVA: poly(vinyl alcohol) [99,127,128] , b) PAA: polyacrylic acid [71,80,97,98] , c) PDMS: polydimethylsiloxane [42,77,83] , d) PDMAA: poly(N,N-dimethylacrylamide) [51,52] , e) PMCMA-co-PCMA: poly[2-(ethylcarbamoyloxy)ethyl methacrylate-co-2-(ethylcarbamoyloxy)ethyl acrylate [56] ], f) PCL: polycaprolactone [69,75] , g) bPEI: branched polyethylenimine [62,71,80] , h) PU: polyurethane. [43,81,[91][92][93] www.advancedsciencenews.com Adv.…”

“…[12,42,43, The reformation of bonding can occur either between two polymer chains, or two or more different polymers, or between polymer chain and other guest small molecules or nanomaterials. As such, it allows the realization of many different kinds functional self-healing materials, which will be discussed later.…”

“…Similarly, Pei's group presented a semitransparent composite conductor comprising a conductive layer of AgNWs percolation network embedded in the surface layer of a Diels-Alder (DA) based healable polymer film. [72] Based on the similar concept of the combination of highly conductive AgNWs layer with healable polymer matrix, other types of healable polymer matrix such as polyurethane crosslinked Diels-Alder adducts, [42,43] thermoplastic polycaprolactone, [75] photochromic healable materials, [76] dynamic-covalent boroxine bonds based polymer [77] and other conductive networks such as copper nanowires (CuNWs), [81] carbon nanotubes [78,80] have also been developed to fabricate self-healable conductors.…”

“…In order to speed up the healing process, external stimuli such as heat and moisture can be applied to improve the chain dynamic and assembly activities. For latter, many types of dynamic covalent bonds including Diels–Alder reaction, disulfide, acylhydrazone, ester, olefin, imine are feasible for the development of such intrinsic self‐healing materials. Due to the slow kinetic of covalent formation, as compared with the non‐covalent case, external stimulus such as heat, pH change, light and catalyst is always needed to trigger the healing process.…”