Physics – Condensed Matter – Materials Science
Scientific paper
2006-03-29
J. Chem. Phys. 125, 014704 (2006)
Physics
Condensed Matter
Materials Science
7 pages, 10 figures, format revtex. Submitted to J. Chem. Phys
Scientific paper
10.1063/1.2210008
The properties of butane (C4H10) lubricants confined between two approaching solids are investigated by a model that accounts for the curvature and elastic properties of the solid surfaces. We consider the linear n-butane and the branched iso-butane. For the linear molecule, well defined molecular layers develop in the lubricant film when the width is of the order of a few atomic diameters. The branched iso-butane forms more disordered structures which permit it to stay liquid-like at smaller surface separations. During squeezing the solvation forces show oscillations corresponding to the width of a molecule. At low speeds (< 0.1 m/s) the last layers of iso-butane are squeezed out before those of n-butane. Since the (interfacial) squeezing velocity in most practical applications is very low when the lubricant layer has molecular thickness, one expects n-butane to be a better boundary lubricant than iso-butane. N-butane possessing a slightly lower viscosity at high pressures, our result refutes the view that squeeze out should be harder for higher viscosities, on the other hand our results are consistent with wear experiments in which n-butane were shown to protect steel surfaces better than iso-butane.
Persson B. N. J.
Sivebaek Ion M.
Tartaglino Ugo
Tosatti Erio
No associations
LandOfFree
Impact of molecular structure on the lubricant squeeze-out between curved surfaces with long range elasticity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Impact of molecular structure on the lubricant squeeze-out between curved surfaces with long range elasticity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Impact of molecular structure on the lubricant squeeze-out between curved surfaces with long range elasticity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-585773