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- Lyotropic structures in a thermotropic liquid crystal doi link

Auteur(s): Toquer Guillaume, Porte Grégoire, Nobili M., Appell Jacqueline, Blanc C.

(Article) Publié: Langmuir, vol. 23 p.4081 (2007)
Texte intégral en Openaccess : istex


Ref HAL: hal-01208070_v1
PMID 17316029
DOI: 10.1021/la062024a
WoS: 000245012900081
Exporter : BibTex | endNote
9 Citations
Résumé:

We have investigated the nature of didodecyldimethylammonium bromide (DDAB)/water aggregates dispersed in4-n-pentyl-4¢-cyanobiphenyl thermotropic liquid crystal (5CB). The structure of this microemulsion has been probedby small-angle neutron and X-ray scattering experiments far above the nematic-to-isotropic phase transition temperatureof the solvent. Our data show that the stability of this system is controlled by strong attractive van der Waals interactionsbetween spherical inverted micelles. These interactions also explain why other swollen mesophases in related cosurfactant/DDAB/water/5CB phase diagrams are not observed. When approaching the isotropic-to-nematic phase transition,scattering experiments additionally confirm the predominance of an increasing attractive interaction due to the 5CBparanematic fluctuations.