Shape dependence in the formation of condensed phases exhibited by disubstituted sucrose esters

Abstract

We report on the self-organizing properties of sucrose esters that are di-(1',6', 1',6, and 6,6')-substituted with aliphatic chains of identical or different chain lengths and levels of saturation. For the materials possessing two saturated aliphatic chains, the compounds exhibited thermotropic lamellar smectic A phases. A remarkable new phase transition was observed for the di-octadecanoyl homologue in which one smectic A phase transformed into another with a continuous change in layer spacing, but with a discontinuous change in the correlation length. The incorporation of long cis-unsaturated chains led to increased cross-sectional areas of the chains relative to the sucrose head groups and, hence, columnar phases were observed.