The surface action on dimer-monomer liquid crystal system

A microscopical mechanism of the interaction between dimerized nematics of 4,n-alkyloxybenzoic acids and hydrophilic solid surfaces is developed. The liquid crystal molecules: monomers and closed dimers are considered like di poles and quadrupoles, respectively. It is demonstrated that in the low-tem perature and the high-temperature ranges of the nematic phase, the mechanis ms of the microscopical interaction are different thus providing different macroscopical effects. The cell thickness and the temperature trends of the scalar order parameter, the effective surface energy and the concomitant a nomalies in these trends are discussed on the basis of the proposed microsc opical mechanism. (C) 2001 Elsevier Science B.V. All rights reserved.