title: Anisometric Polyelectrolyte/Mixed Surfactant Nanoassemblies Formed by the Association of Poly(diallyldimethylammonium chloride) with Sodium Dodecyl Sulfate and Dodecyl Maltoside.
abstract: The soluble complexes of oppositely charged macromolecules and amphiphiles, formed in the one-phase concentration range, are usually described on the basis of the beads on a string model assuming spherelike bound surfactant micelles. However, around and above the charge neutralization ionic surfactant to polyion ratio, a variety of ordered structures of the precipitates and large polyion/surfactant aggregates have been reported for the different systems which are difficult to connect to globular-like surfactant self-assembly units. In this article we have demonstrated through SAXS measurements that the structure of precipitates and those of the soluble polyion/mixed surfactant complexes of poly(diallyldimethylammonium chloride) (PDADMAC), sodium dodecyl sulfate (SDS), and dodecyl-maltoside (DDM) are strongly correlated. Specifically, SDS binds to the PDADMAC molecules in the form of small cylindrical surfactant micelles even at very low SDS-to-PDADMAC ratios. In this way, these anisometric surfactant self-assemblies formed in excess polyelectrolyte mimic the basic building units of the hexagonal structure of the PDADMAC/SDS precipitate and/or suspensions formed at charge equivalence or at higher SDS-to-PDADMAC ratios. The presence of DDM reduces the cmc and cac for the system but does not alter significantly the structure of the complexes in either the one-phase or two-phase region. The only exception is for samples at SDS-to-PDADMAC ratios close to charge neutralization and a high concentration of DDM where the precipitate forms a multiphasic or distorted hexagonal structure.
authors.affiliation: †Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Plazzotta
authors.affiliation: ‡Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter Sétány 1/A, 1117 Budapest, Hungary.
authors.forename: Edit
authors.initials: E
authors.lastname: Fegyver
authors.affiliation: ‡Laboratory of Interfaces and Nanosized Systems, Institute of Chemistry, Eötvös Loránd University, Pázmány Péter Sétány 1/A, 1117 Budapest, Hungary.|§Department of Chemistry, University J. Selyeho, 945 01 Komárno, Slovakia.
authors.forename: Róbert
authors.initials: R
authors.lastname: Mészáros
authors.affiliation: †Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Pedersen