Interactions and Aggregations in Aqueous and Brine Solutions of Poly(diallydimethylammonium chloride)/Sodium Bis(2-ethylhexyl) Sulfosuccinate

Abstract

The interactions between the anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and the polycation poly(diallydimethylammonium chloride) (PDDAC), the aggregations of AOT and PDDAC-bound AOT in PDDAC/AOT aqueous solutions, and the influence of salt on the interactions and aggregations have been studied by isothermal titration calorimetry (ITC), dynamic light scattering (DLS), and negative staining transmission electron microscopy (TEM). The adsorptions of AOT onto PDDAC and the formations of PDDAC-bound AOT micelles, free AOT micelles, and AOT vesicles were examined, and the corresponding critical concentrations were determined. Combining calculations of thermodynamic parameters with the above three experimental techniques, it was shown that the micellization of free AOT is driven by entropy gain, while the adsorption of AOT onto PDDAC and the micellization of PDDAC-bound AOT are driven by both enthalpy and entropy. It was also found that addition of salt enhances the binding of AOT onto PDDAC through the ion exchange and favors the formations of PDDAC/AOT micelles, free AOT micelles, and free AOT vesicles but prevents the transition of PDDAC/AOT micelles to the vesicles. Thermodynamic analysis suggested that the adsorption of AOT onto PDDAC and the micellization of PDDAC/AOT in PDDAC/AOT brine solutions are different in mechanism compared with that in corresponding aqueous solutions.

Moldable Material from ε-Poly-l-lysine and Lignosulfonate: Mechanical and Self-Healing Properties of a Bio-Based Polyelectrolyte Complex

“…It has been reported that the interaction between sulfonate and primary amino groups in a polyelectrolyte complex is stronger than that with quaternary ammonium groups . In fact, the ε-PL/BEHS complex is a water-insoluble complex; however, the PDADMACl/BEHS complex is a small micellar complex that dissociates at low BEHS concentration . These findings imply a stronger interaction between sulfonate and a primary amino group than with a quaternary ammonium group.…”

“…23 In fact, the ε-PL/BEHS complex is a water-insoluble complex; 11 however, the PDADMACl/BEHS complex is a small micellar complex that dissociates at low BEHS concentration. 24 These findings imply a stronger interaction between sulfonate and a primary amino group than with a quaternary ammonium group. The stronger interaction between L-SO 3 Na (sulfonate group) and ε-PL (primary amino group) than that with PDADMACl (quaternary ammonium group) may contribute to superior stress at break and a high Young’s modulus and toughness, despite the lower molecular weight of ε-PL.…”

Twin-tailed surfactant induced conformational changes in bovine serum albumin: a detailed spectroscopic and physicochemical study

“…Thus, the cmc can be determined from the intercept of the two linear extrapolations of each half of the plot, and the enthalpy of micellization (DH mic ) can be obtained from the difference between the observed enthalpies of the two linear segments of the plots. 49,50 The values of cmc and DH mic for both surfactants in the presence and absence of BSA are given in Table S3 of ESI. † It shows that the cmc values for AOT coincides with the values measured by the other techniques used.…”

Antimicrobial Activity of ε-Poly-l-lysine after Forming a Water-Insoluble Complex with an Anionic Surfactant

“…Here, we report on the preparation and availability of the water-insoluble complex formed by PL n + and the synthetic anionic surfactant, bis­(2-ethylhexyl) sulfosuccinate (BEHS – , is also commercialized as AOT) anion. Studies have demonstrated that the formation of a complex between BEHS – anion and a cationic compound, for example, poly­( N -ethyl-4-vinylpyridinium bromide), poly­(diallydimethylammonium chloride), and benzyldimethyltetradecylammonium, − strongly suggesting that the BEHS – anion may also interact with PL n + . As expected, the water-insoluble complex was obtained, and the antimicrobial activity of the PL n + /BEHS – -complex, which is soluble in organic solvents, was investigated through coating a cellulose acetate membrane.…”