Surface Characterization and Tribological Behavior of Graphene-Reinforced Cellulose Composites Prepared by Large-Area Spray Coating on Flexible Substrate

• Main Authors: Shih-Chen Shi, Chih-Chia Wang, Yung-Chen Cheng, Yue-Feng Lin
• Format: Article
• Language: English
• Published: MDPI AG 2020-12-01
• Series: Coatings
• Subjects: tribology; wear; graphene; cellulose; large area; spray coating
• Online Access: https://www.mdpi.com/2079-6412/10/12/1176

A large-area spray coating process is introduced to efficiently apply a graphene/Cu/cellulose composite on a flexible glass substrate. The dispersion characteristics of nano-additives are measured and the Tyndall effect observed. The characteristics of the composite coating such as the film thickness, surface roughness, water contact angle, and lubricating characteristics are measured. The tribological properties of the composite coating are measured using a ball-on-disk. The wear width of the abrasive parts, as well as the wear and friction coefficient of the grinding balls, are investigated. Adding graphene/Cu helps to improve the anti-wear ability of cellulose. The transfer layer was observed using the Raman spectroscopy and mapping technology. Finally, the lubricating mechanism is discussed, and the wear mechanism is proposed. Nanoparticles existed in the wear track as the third-body particles and improved the load capacity of the composites. The wear mechanism of the composites is discussed in terms of the worn surfaces and the analysis of the transfer film with the third-body approach.