Association of oppositely charged polyelectrolyte and surfactant in solution: equilibrium and nonequilibrium features

Abstract

The association of polyelectrolytes and surfactants bearing charges of opposite signs has been for long time considered under an equilibrium framework. However, this is far to provide a true description of the physico-chemical rules of the association process when kinetically arrested nonequilibrium states are formed. This is the result of specific interaction pathways between the polyelectrolyte chains and the surfactant molecules determined by the mixing procedure and the mixture composition. In fact, the specific characteristics of the method used for the mixture can induce local inhomogeneities in the mixture composition which can govern the properties of the obtained supramolecular aggregates, driving to the systems to a situation far from the true equilibrium. This topical review tries to provides to the reader a general perspective of the role of the nonequilibrium aspects in the control of the polyelectrolyte-surfactant association process, and how these impact on the obtained supramolecular nanoassemblies, and their properties.

Physico-chemical challenges on the self-assembly of natural and bio-based ingredients on hair surfaces: towards sustainable haircare formulations

“…In fact, the association of anionic surfactant and cationic polyelectrolytes and their deposition on hair fibres is on the bases of the conditioning process. [72][73][74][75][76] In fact, conventional conditioning shampoo performance depends on the interaction of cationic polymers with anionic surfactants leading to the formation of phase separate coacervates during the rinse stage. In fact, under application conditions, shampoos undergo a phase separation process characterized by the appearance of phase separated polyelectrolyte-surfactant complexes enriched in the cationic polyelectrolyte (coacervate) which contribute to the conditioning process.…”

Photoresponsive arylazopyrazole surfactant/PDADMAC mixtures: reversible control of bulk and interfacial properties

“…[4][5][6][7] Owing to their widespread use in applications, the properties of P/S mixtures with classical surfactants like dodecylsulfate or alkylammonium in bulk solutions and at interfaces are studied extensively to the present day. [5][6][7][8][9][10][11][12] Using different P/S mixing ratios allows one to tailor soft matter properties such as the size of the P/S aggregates that form after mixing or the stability of aqueous foams.…”

Pressure Changes Across a Membrane Formed by Coacervation of Oppositely Charged Polymer–Surfactant Systems

“…This can lead to kinetically trapped states which show no significant changes on an observable time scale but differ from the equilibrium situation. 24,25 We previously employed the interactions between the anionic biopolymer xanthan gum (XG) and cationic C n TAB surfactants in an aqueous solution to form growing polymer− surfactant membranes in a Hele−Shaw experimental setup. 26 The same system can be used for capsule formation, which is the focus of this work.…”

“…In systems where polymer–surfactant complexes are formed under the presence of strong concentration gradients, it is essential to consider kinetic effects and mass transfer processes. This can lead to kinetically trapped states which show no significant changes on an observable time scale but differ from the equilibrium situation. , …”