INDUCTION OF SMECTIC A(D)-PHASE IN POLAR SYSTEMS .1. MIXTURES OF NCBB AND NOCB

Bicomponent mixtures of 4-cyanobiphenyl-4'-yl 4'-alkylbiphenyl-4-carboxylates (nCBB) and 4-alkoxy-4'-cyanobiphenyls (nOCB) were studied and their phase diagrams obtained by thermonicroscopy. The strong enhancement of a smectic A(d) phase in mixture with the smectic members of the nOCB (n greater-than-or-equal-to 8) series and the induction of a smectic A(d) phase in the shape of an island surrounded by a nematic phase in mixtures with the nematic members of the nOCB (n < 8) series were observed. The influence of aliphatic chain length on the observed phenomena is discussed.