Synergistic water lubrication effect of self-assembled nanofilm and graphene oxide additive

• Published in: Applied surface science 2018-10, Vol.455, p.1070-1077
• Main Authors: Li, Xing, Lu, Hailin, Guo, Junde, Tong, Zhe, Dong, Guangneng
• Format: Article
• Language: English
• Subjects: Graphene oxide; Nano-additives; Self-assembled nanofilm; Tribofilms; Water lubrication
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.06.036

•Self-assembly 3-aminopropyltriethoxysilane nanofilm was fabricated on albronze.•The nanofilm changed albronze surface from hydrophobic to hydrophilic.•Graphene oxide was utilized as water lubrication additives.•The nanofilm could promote formation of graphene oxide tribofilms and improve lubrication effect. In this study, a pretreatment method was proposed to enhance the lubrication effect of GO as additives. During pretreatment, 3-aminopropyltriethoxysilane (3-APS) nanofilm was successfully fabricated on substrate surface by self-assembled technique. The 3-APS nanofilm with amino groups can chemically adsorb the GO nanosheets in water. Thus the graphene oxide sheets could deposit on 3-APS nanofilm quickly and last longer, forming durable tribofilms on sliding contact areas. Scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS) and water contact angle (WCA) characterizations revealed the successful preparation of 3-APS nanofilm. Importantly, tribological investigations indicated that under the synergistic effect of 3-APS nanofilm and GO additives, the friction coefficient and the wear rate decreased by 43.6% and 79.7%, compared to those of albronze lubricated by deionized water. Control experiments by respectively using GO additive, and 3-APS nanofilm were performed as well. It is found that using 3-APS nanofilm and GO additives together exhibits the best tribological performances among all the samples. Furthermore, GO tribofilms were detected on wear tracks and relative lubricating mechanisms were elucidated.