Size Effect of the Alkyl Chain of the Surfactant on the Chemomechanical Movement of a Polymer Gel

Universal Binding Behavior for Ionic Alkyl Surfactants with Oppositely Charged Polyelectrolytes

“…The outcome of such experiments of relevance here is the intrinsic cooperative binding strength parameter Ku . This intrinsic binding strength has been reported by numerous authors for a wide variety of salt-free PE–surfactant mixtures in the literature (as listed in Table ) ,− ,− ,− and thus conveniently serves as an intrinsic property characteristic of surfactant binding for each specific system. Ultimately, determining how this binding strength parameter governs the solution thermodynamics and the microstructure of the PSCs is desired for the rational formulation of PSCs with specific properties, such as elastic modulus and tackiness. , To date, there is no general predictive method for formulating specific microstructures in PSCs, especially highly ordered structures such as cubic, cylindrical, hexagonal, and lamellar morphologies, ,, and their associated properties, ,, yet it is reasonable to expect that all of these depend fundamentally on the strength of the cooperative binding of the surfactant to the polyelectrolyte.…”

“…In the following, we generalize the binding behavior of PE–surfactant mixtures with opposite charges by examining the cooperative binding constant ( Ku l,exp ) determined over a variety of salt-free PE–surfactant mixtures from our work and literature reports. ,− ,− ,− , These Ku l,exp values are reported for systems that are relevant to foods, pharmaceuticals, and cosmetics, and these systems are summarized in Table . They include polycations and polyanions.…”

“…Observations in the literature of surfactant binding to PE chains support this choice of coarse-grained properties. 28,47,50,52,58,59 For example, larger binding affinity was found in PE−surfactant mixtures with greater PE charge density 28,47 or more hydrophobic groups. 47,59 Consequently, compiling and summarizing observations of binding in terms of these properties turns out to be useful to deduce rules for formulating PSCs.…”

Complexation of Fluorosurfactants to Functionalized Solid Surfaces: Smart Behavior

“…Polyelectrolytes can spontaneously interact with oppositely charged surfactants in aqueous solution to produce polyelectrolyte−surfactant complexes according to a strict 1:1 stoichiometry required for overall charge balance. − These systems have been extensively studied in the past as a function of many parameters including surfactant tail length, − nature of the polyelectrolyte, − density of charge sites along the polyelectrolyte backbone, ,,,, solution pH, and the incorporation of low molecular weight electrolyte. ,,,− A combination of electrostatic attraction between the oppositely charged constituents and interactions between the long-chain surfactant tails is understood to culminate in a highly cooperative binding process, which leads to stabilization of the polyelectrolyte−surfactant complex. ,,,,− In the solid phase, these materials tend to display a layered arrangement derived from demixing of the polar polyelectrolyte backbone and the hydrophobic surfactant tails. The precise structure is influenced by a number of factors which include the relative volume fractions of ionic and alkyl phases present, and the molecular geometry of the surfactant molecules .…”