Host: The Japan Society of Vacuum and Surface Science
Water lubrication has received considerable attention not only due to the importance as the fundamental mechanism of low friction in biological lubrication but also due to the benefits for energy efficiency and low environmental burden in machinery (from the SDGs standpoint). The excellent fluidity of water is maintained even in molecular scale gap between contacting surfaces, which is, of course, the major origin of low friction in boundary lubrication. However, this high fluidity may result in the easily squeezed out of water from the gap, which leads to surface damage. Selecting suitable chemicals as lubricant additives is one of the solutions for this problem; the impact of using water-soluble polymers as additives for water lubrication was investigated. We found that some silicone-type amphiphilic polymer formed an adsorbed layer on surface and exhibited excellent tribological performance mainly due to the easy slippage of hydrated water on polymer layer surface.
