LUBRICATION WITH LIQUID CRYSTAL: MINIMIZATION OF FRICTION AT VARIOUS SPEEDS USING AUTONOMOUS CONTROL OF ITS VISCOSITY

摘要

(1) When lubricated by 5CB, changes in the film thickness and friction coefficient for various speeds are quite similar to those in ordinary liquids. (2) When lubricated by 5CB-HDA, the boundary films formed by HDA induce surface anchoring that makes 5CB molecules align perpendicular to the solid surfaces. This effect competes with the flow alignment that makes 5CB molecules align to the flow direction, which induces an increase in the viscosity of 5CB in the mixed lubrication regime. (3) The increase in the viscosity of 5CB induced by HDA reduces the friction coefficient in the mixed lubrication regime, which results in a constant friction coefficient region in the Stribeck curve on the left side of the minimum friction coefficient point. (4) These changes in the film thickness and friction coefficient for 5CB-HDA occur autonomously, without the need for external fields such as electric fields to be applied. The boundary films are formed spontaneously at the contact and reduce the friction coefficient in the boundary lubrication regime.