| Autor: |
Margareta Socaciu, Stelian Radu, J. Neamtu, Marcela Ursache, Cristian Sarpe-Tudoran, G. Bratulescu |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
ROMOPTO '97: Fifth Conference on Optics. |
| ISSN: |
0277-786X |
| DOI: |
10.1117/12.312817 |
| Popis: |
Some interesting experimental results involving new synthesized liquid crystals. derivatives of 44-dihidroxyazobenzeneand 4.4'-dihidroxy-azoxvbenzene inferred by means of optical absorption spectroscopy are exposed. The absorption spectradependence on the sample temperature in both heating and cooling processes is investigated. At the same time, the opticaldensity is recorded at a fixed wavelength and it presents significant variations at phase transition temperatures. These datacon1plete the results correlated with mesomorphism. obtained by classical techniques (DTA and microstructural analysis inpolarized light).Keywords: liquid crystals. azo and azoxv derivatives. phase transitions. optical absorption spectroscopy1. P4TRODUCTION Azo and azoxybenzene with different substituents at the end of the molecule constitute a large group of mesomorphic substances. It is of great interest to investigate the influence of the molecular structure, particularly thenature of terminal groups, on the mesomorphic properties and also on the spectroscopic manifestations. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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