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Anisotropic Surface Order in the Isotropic Phase of Nematic Liquid Crystals
Author(s) -
Harthi Salim Al,
George A. K.
Publication year - 1997
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.2170320405
Subject(s) - liquid crystal , isotropy , anisotropy , surface tension , materials science , condensed matter physics , drop (telecommunication) , phase (matter) , thermodynamics , optics , chemistry , physics , organic chemistry , telecommunications , computer science
A spinning‐drop technique was used to study the thermal variation of surface tension of two nematic liquid crystals at the interface with an isotropic fluid. A sharp increase in interfacial tension was observed in the vicinity of the nematic‐isotropic transition. The interfacial tension‐temperature characteristics, unlike monotonically decreasing dependence found in most isotropic fluids, showed regions of positive slope, both in the isotropic and anisotropic phases. A positive slope in the isotropic region of the liquid crystal is interesting since it implies that excess order has developed at the surface while the buk interior remains isotropic.