Deposition of Multiscale Thickness Graphene Coating by HarnessingExtreme Heat and Rapid Quenching: Toward Commercialization
Authors: iswajyoti Mukherjee, O. S. Asiq Rahman, Aminul Islam, Krishna Kant Pandey and Anup Kumar Keshri
Abstract: Deposition of graphene as a coating material over large-scale areas isan intense topic of research because of complexities involved in the existingdeposition techniques. Higher defects and compromised properties restricted inrealizing the full potential of graphene coating. This work aims to deposit graphenecoatings by adopting a traditional technique, that is, plasma spraying, which hasinherent merits of extremely high cooling rate (∼106K/s) and low plasma exposuretime (∼0.1−10μs). Graphene nanoplatelets (GNPs) were spray-dried intospherical agglomerates (∼60μm dia.) and coatings were deposited over a widerange of surfaces. Continuous monitoring of temperature and velocity of in-flightGNPs was done using a diagnostic sensor. Deposition of GNP coatings was theresult of striking of quasi-2D melted GNPs with higher velocity (∼197 m/s) towardthe substrate. Postcharacterizations confirmed that GNPs did not collapse even afterbeing exposed to harsh environments in plasma. Instead, high temperatures provedto be beneficial in purifying the commercial GNPs. The coatings were transparenteven in the short-wavelength infrared region and remained electrically conductive. A proof-of-concept was established bycarrying out preliminary corrosion and antifriction tests. Outstanding reduction of∼3.5 times in corrosion rate and 3 times incoefficient of friction was observed in GNP-deposited coating. It is envisaged that graphene coating by plasma spraying canbring a revolution in commercial sectors.
Publishing Date: June 2019
Published in: ACS Applied Materials and Interface