Observation of two biaxial nematic mesophases in the tetradecyltrimethylammonium bromide/decanol/water system

dc.creatorde Melo, AA
dc.creatorLaverde, A
dc.creatorFujiwara, FY
dc.date2003
dc.dateFEB 18
dc.date2014-11-13T12:01:30Z
dc.date2015-11-26T18:07:14Z
dc.date2014-11-13T12:01:30Z
dc.date2015-11-26T18:07:14Z
dc.date.accessioned2018-03-29T00:49:23Z
dc.date.available2018-03-29T00:49:23Z
dc.identifierLangmuir. Amer Chemical Soc, v. 19, n. 4, n. 1127, n. 1132, 2003.
dc.identifier0743-7463
dc.identifierWOS:000181017700022
dc.identifier10.1021/la026618z
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/62322
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/62322
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/62322
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1293543
dc.descriptionThe phase diagram of the nematic mesophases present in the tetradecyltrimethylammonuim bromide/n-decanol/water system was determined. Two distinct biaxial nematic mesophases with opposite diamagnetic and optical anisotropies were identified using H-2 NMR spectroscopy and optical microscopy with polarized light. Two nematic biaxial phases were observed in a very narrow region between the two uniaxial nernatic mesophases. The sequence of phase changes, hexagonal-calamitic N-C-biaxial N-BX(+)-biaxial N-BX(-) -discotic N-D-lamellar mesophases, was observed with increasing decanol content. The phase transition between the two biaxial mesophases is first order, while the phase transitions between the N-C and N-BX(+) and the NBX--N-D mesophases are second order. The order parameters of the ionic headgroup of the surfactant, determined from the H-2 quadrupolar splittings, indicate that the average micelle size decreases with the decanol content in the N-C and N-BX(+) mesophases and increases with the decanol content in the N-BX(-) and N-D mesophases.
dc.description19
dc.description4
dc.description1127
dc.description1132
dc.languageen
dc.publisherAmer Chemical Soc
dc.publisherWashington
dc.publisherEUA
dc.relationLangmuir
dc.relationLangmuir
dc.rightsfechado
dc.sourceWeb of Science
dc.subjectLyotropic Liquid-crystals
dc.subjectPhase-transitions
dc.subjectNonspherical Micelles
dc.subjectScattering
dc.subjectOrder
dc.subjectMolecules
dc.subjectBehavior
dc.subjectBromide
dc.subjectDecanol
dc.titleObservation of two biaxial nematic mesophases in the tetradecyltrimethylammonium bromide/decanol/water system
dc.typeArtículos de revistas


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