Effects of Gas or Vapor Adsorption on Adhesion, Friction, and Wear of Solid Interfaces

Abstract

The adsorption of vapor molecules plays an important role in countless fields and is increasingly realized to be critical in tribology, which encompasses adhesion, friction, and wear of surfaces. This feature article reviews experimental methods for quantifying gas and vapor adsorption on flat solid surfaces under equilibrium conditions (ambient pressure and temperature) as well as the effects of these adsorbates on the adhesion, friction, and wear of various materials. Particular attention is given to species that are present in the ambient environment such as water (humidity) and organic vapors. These adsorbed species can have drastic yet varied influences on tribology depending on the surface chemistry of materials. Despite prolonged and ubiquitous observations in a broad range of materials and vapors, a fundamental understanding of the effect of adsorbed gases and vapors on the adhesion, friction, and wear of surfaces has begun only recently through surface-sensitive characterization.

Vapors in the ambient—A complication in tribological studies or an engineering solution of tribological problems?

“…The water layer adsorbed on fused quartz ( Fig. 6(a)) behaved like a typical physisorption layer [93,109]. The adsorption of water on soda lime glass differed drastically with three distinct peaks identified at ~3,200, ~3,430, and ~3,680 cm −1 (Fig.…”

Effect of coadsorption of water and alcohol vapor on the nanowear of silicon

“…The ethanol adsorbate can not only prevent the formation of Si substrate -O-Si tip bonded bridges during rubbing process, but also increase the energy barrier of Si-O-Si bonds dissociation on silicon surface [22]. Since the adsorption of longer chain molecule may further increase the energy barrier of Si-O-Si bonds dissociation on silicon substrate, the propanol or butanol vapor may have a better capability to resist the tribochemical wear of silicon surface [22,42,43].…”

Surface removal of a copper thin film in an ultrathin water environment by a molecular dynamics study

“…In addition, the slurry is another factor that has a significant effect on the polishing environment and makes the polishing process more complex [12−14]. As one of the simple but key components of a slurry, water not only carries the other components but also acts as an efficient lubricant, which affects the friction and wear behavior of the polished surface, material removal rate, and quality of the polished surface [15]. By studying the nanoscale friction and wear properties of silicon wafer, Chen et al found that the wear rate and friction coefficient in water lubrication were lower and smaller, respectively, than those under dry friction conditions, and the wear mechanism of water lubrication was considered to be a molecule-scale removal process [16].…”