摘要:

The phase behaviour of the binary systems ANBC(nC)-n-tetradecane, for nC = 8, 16 and 18, was examined using DSC, paying special attention to the role of the alkoxy chain of the ANBC molecule in the D phase. The dependence of the SmC-D and D-isotropic liquid transition temperatures upon the apparent average number of paraffinic carbon atoms closely resembles the nC dependence in the series of neat ANBCs, demonstrating that the alkoxy chain behaves, at least in part, like the solvent in lyotropic liquid crystals. The D phase was not detected in ANBC(8)-n-tetradecane.

ISSN:0267-8292    

DOI:10.1080/026782998206047

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The Landau-de Gennes model of the boundary layer phase transition in nematic liquid crystals is extended to include electric field effects. Calculations are performed in the case of a semi-infinite nematic sample bounded by a solid wall. The phase diagrams presented show that the prewetting transition can be induced by the electric field. The transition moves to higher temperature with increasing field and disappears above the prewetting critical point. A system exhibiting partial wetting should transit to complete wetting under a high enough electric field. These predictions are confirmed within the actual experimental limits.

ISSN:0267-8292    

DOI:10.1080/026782998206056

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The crystal and mesophase transitions of the discotic material 5,10,15,20-tetrakis(4- n-dodecylphenyl)porphyrin have been studied by high pressure DTA and wide angle X-ray diffraction. At lower pressures, the discotic lamellar (DL) phase is enantiotropic, but at higher pressures above a critical point determined as 240MPa and 170 C the DL phase is monotropic.

ISSN:0267-8292    

DOI:10.1080/026782998206065

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor