Akpinar Erol, Guner Emre, Demir-Ordu Oznur, Neto Antônio Martins Figueiredo
Bolu Abant Izzet Baysal University, Faculty of Arts and Sciences, Department of Chemistry, Golkoy, 14030, Bolu, Turkey.
Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, 05508-090, São Paulo, SP, Brazil.
Eur Phys J E Soft Matter. 2019 Apr 8;42(4):44. doi: 10.1140/epje/i2019-11806-y.
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.
制备了一些十四烷基烷基溴化铵表面活性剂的溶致四元混合物，以研究表面活性剂头基大小对不同溶致向列相稳定性的影响。通过在溴化钠/癸醇（DeOH）/水的混合物中加入十四烷基烷基溴化铵（TTAABr）来制备溶致混合物。通过激光锥光法测定单轴向双轴向列相转变。从稀释的二元表面活性剂/水溶液的电导率测量中评估了一些胶束化参数，如临界胶束浓度、反离子结合度和胶束化吉布斯自由能。结果表明，表面活性剂分子的头基大小影响两亲分子聚集体的拓扑结构。此外，每个表面活性剂头基的有效面积是稳定溶致双轴向列相的关键参数。
