Effect of director fluctuations on the surface tension of nematic liquid crystals.
We discuss the surface tension of a thermotropic nematic liquid crystal near the nematic-isotropic temperature. We find that certain experimentally observed features of the temperature trend that present difficulties to mean-field theoretical approaches can be attributed to director fluctuations. Our main result is the possibility of a minimum below T(NI) if the anchoring extrapolation length scales with reduced temperature in the spinodal limit as tx, with x<1. We also show in the case of partial nematic wetting that dampening of director fluctuations at the surface by anchoring at the nascent interface can reverse the sign of the surface tension discontinuity at T(NI).
Braun
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FN
Department of Physics and Astronomy, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom. braun@ph.ed.ac.uk