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A New Mechanism for Lubrication in Liquid Crystals

Published online by Cambridge University Press:  15 February 2011

Robijn F. Bruinsma  and
Cyrus R. Safinya
Robijn F. Bruinsma
Affiliation:
Materials and Physics Departments, and the Materials Research laboratory, University of California, Santa Barbara, CA 93106.
Cyrus R. Safinya
Affiliation:
Materials and Physics Departments, and the Materials Research laboratory, University of California, Santa Barbara, CA 93106.
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Abstract

Recent synchrotron X-ray scattering studies on the thermotropic liquid crystal lubricant 8CB under shear flow have shown that for high shear rates the smectic layers are oriented perpendicular to the orientation assumed by conventional solid layered lubricants. This result invalidates existing theories of the lubrication mechanism of these materials. We show that the new orientation is the result of flow deformation of thermal fluctuations. This same mechanism is found to create a “normal stress” lift-force which we propose as the new lubrication mechanism.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 290: Symposium N – Dynamics in Small Confining Systems , 1992 , 3
Copyright
Copyright © Materials Research Society 1993

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