Effect of head-group size of some tetradecylalkylammonium bromide surfactants on obtaining the lyotropic biaxial nematic phase

Author(s)

Akpinar, Erol ^[1] ; Guner, Emre ^[1] ; Demir-Ordu, Oznur ^[1] ; Figueiredo Neto, Antonio Martins ^[2]

Affiliation

^[1] Abant Izzet Baysal Univ, Fac Arts & Sci, Dept Chem, TR-14030 Golkoy, Bolu - Turkey

^[2] Univ Sao Paulo, Inst Fis, Rua Matao 1371, BR-05508090 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: EUROPEAN PHYSICAL JOURNAL E; v. 42, n. 4 APR 2019.
• Web of Science Citations: 1

Abstract

Lyotropic quaternary mixtures of some tetradecylalkylammonium bromide surfactants were prepared to examine the effect of the size of the surfactant head group on the stabilization of different lyotropic nematic phases. The lyotropic mixtures were prepared by the addition of the tetradecylalkylammonium bromides (TTAABr) in the mixture of NaBr/decanol (DeOH)/water. The uniaxial to biaxial nematic phase transitions were determined via laser conoscopy. Some micellization parameters such as critical micelle concentration, degree of counterion binding and micellization Gibbs energy were evaluated from the electrical conductivity measurements of diluted binary surfactants/water solutions. The results indicate that the head-group size of the surfactant molecules influences the amphiphilic molecular aggregate topology. Moreover, the effective area per surfactant head group is a key parameter on stabilizing the lyotropic biaxial nematic phase. (AU)

• FAPESP's process: 16/24531-3 - Structural and biophysics properties of native and modified lipoproteins
• Grantee: Antonio Martins Figueiredo Neto
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/50983-3 - INCT 2014: complex fluids
• Grantee: Antonio Martins Figueiredo Neto
• Support Opportunities: Research Projects - Thematic Grants