Thermodynamic and Interfacial Study of Two Liquid Crystals substituted with polyethylene oxyde (POE) chains.

In this work thermodynamic and surface properties of two liquid crystals su bstituted with polyethylene oxyde (POE) chains are considered. The first of them is N,N'diphenyl-[4-(2,3,4 -tri(2-(2-metoxyethoxy) ethoxy) benzylidene )imine] piperidine (LC1) and the second is 2hydroxy-3-methyl-4-[4-(2-(2-but oxyethoxy)ethoxy)]-4'-[4-(2-(2-butoxyethoxy)ethoxy)styryl] azobenzene (LC2) . The POE chains increase the polarity and induce an amphiphilic character of these compounds. The inverse gas chromatography was used to determine ex cess functions of selected solutes infinitely diluted in the liquid or nema tic LC1 and LC2. The formation of multilayers by LC1 and LC2 at the air/sat urated aqueous NaCl interface was observed using the Langmuir balance techn ique. Results obtained show that the hydrophilic character of the compounds may play an important role in the mechanism of the molecular recognition d uring chromatographic separations. (C) 2001 Elsevier Science B.V. All right s reserved.