Thermotropic and lyotropic properties of long chain alkyl glycopyranosides. Part II. Disaccharide headgroups

We have investigated the thermotropic and lyotropic properties of some long chain alkyl glycosides with disaccharide headgroups. The thermotropism was measured with polarising microscopy and additionally the lyotropism with t he contact preparation method, Fourier-transform Infrared (FTIR) spectrosco py, X-ray diffraction and small angle neutron scattering. A broad thermotro pic as well as lyotropic polymorphism was found. The compounds displayed th ermotropic S-A (lamellar) and cubic phases, and the investigation of the ly otropic phase behaviour led to the observation of inverted bicontinuous cub ic V-II phases, lamellar L-alpha phases, normal bicontinuous cubic V-I phas es, normal columnar H-I phases, normal discontinuous cubic I-I f phases and lyotropic cholesteric phases. The phases are discussed with respect to the chemical structures that have been varied systematically to derive structu re-property relationships. (C) 2000 Elsevier Science Ireland Ltd. All right s reserved.