| 1 | Author
| A. Würflinger, M. Sandmann, W. Weissflog | Requires cookie* | | Title
| PVT Measurements on 3-Cyanobenzyl 2,5-bis(4-/i-octyloxybenzoyl- oxy)benzoate up to 250 MPa and 423 K  | | | Abstract
| P, V m , T data have been measured for the nematic and isotropic phases of 3-cyanobenzyl 2,5-bis (4-n-octyloxybenzoyloxy)benzoate between 273 and 423 K and up to 250 MPa. The volume changes accompanying the crystal -nematic and nematic -isotropic transitions have been determined. The cor-responding enthalpy changes have been calculated using the Clausius-Clapeyron equation. The p, V m , T data enable also to estimate the volume entropy for the nematic-isotropic transition. It is found that the configurational part of the transition entropy amounts to 80%, this portion being distinctly larger than found in previous studies for conventional rod-like liquid crystals. | | |
Reference
| Z. Naturforsch. 55a, 823—827 (2000); received July 17 2000 | | |
Published
| 2000 | | |
Keywords
| Aryl-branched Liquid Crystals, High Pressure, pVT\ Phase Transitions, Thermodynamics | | |
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| default:Reihe_A/55/ZNA-2000-55a-0823.pdf | | | Identifier
| ZNA-2000-55a-0823 | | | Volume
| 55 | |
2 | Author
| A. Wiirflinger, W. Weissflog | Requires cookie* | | Title
| DTA and p VT Measurements on 4-cyanobenzyI-5- (4-n-octyloxybenzoyloxy)-2-undecyloxybenzoate up to 250 MPa and 383 K  | | | Abstract
| The phase diagram of 4-cyanobenzyl-5-(4-«-octyloxybenzoyloxy)-2-undecyloxybenzoate (4CNOUB) has been established with differential thermal analysis (DTA). The pressure range for the smectic A phase is limited, resulting in a triple point at 165 MPa and 378.26 K. p, Vm, T data have been measured for the smectic and istotropic phases of 4CNOUB between 243 and 383 K and up to 250 MPa. The vol-ume changes accompanying the crystal -smectic and scmectic -isotropic transitions have been deter-mined. The corresponding enthalpy changes have been calculated using the Clausius-Clapeyron equa-tion. The p, Km, 7 data enable also to estimate the volume entropy for the smectic -isotropic transition and the volume dependence of the clearing temperature. | | |
Reference
| Z. Naturforsch. 55a, 936—940 (2000); received September 15 2000 | | |
Published
| 2000 | | |
Keywords
| Aryl-branched Liquid Crystals, High Pressure, pVT\ Phase Transitions, Thermodynamics | | |
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| default:Reihe_A/55/ZNA-2000-55a-0936.pdf | | | Identifier
| ZNA-2000-55a-0936 | | | Volume
| 55 | |
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