title: Transitions in the Molecular Configuration and Aggregates for Mixtures of a Star-Shaped Hexameric Cationic Surfactant and a Monomeric Anionic Surfactant.
abstract: A hexameric cationic ammonium surfactant (PAHB), in which six amphiphilic moieties were connected by a star-shaped spacer group, adopted star-shaped, claw-like, and pyramid-like molecular configurations in aqueous solution, depending on the concentration. Herein, we studied the effect of adding sodium dodecyl sulfate (SDS) on the configuration and aggregation behavior of PAHB. Taking these three configurations of PAHB as initial states, the addition of SDS caused transitions of the star-shaped and claw-like configurations into a pyramid-like configuration, whilst the pyramid-like configuration remained unchanged. Moreover, the SDS/PAHB aggregates experienced transition from small spheres to large spherical fingerprint-like aggregates, no matter the initial state of PAHB. Molecular packing in the aggregates was also studied. These results have improved our understanding about the cooperative interactions between star-shaped oligomeric surfactants and monomeric surfactants, which should guide future applications of this unique type of surfactant.
authors.affiliation: Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
authors.forename: Fulin
authors.initials: F
authors.lastname: Qiao
authors.affiliation: Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
authors.forename: Meina
authors.initials: M
authors.lastname: Wang
authors.affiliation: Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. yxfan@iccas.ac.cn.
authors.forename: Yaxun
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Key Laboratory of Colloid and Interface Science, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. yilinwang@iccas.ac.cn.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Wang
keywords: fingerprint-like aggregate; molecular configuration; monomeric anionic surfactant; oligomeric cationic surfactant