Specific Counterion Effects on the Competitive Co-adsorption of Polyelectrolytes and Ionic Surfactants

Velegol, Stephanie Butler; Tilton, Robert D.

doi:10.1006/jcis.2002.8273

Cited by 27 publications

(28 citation statements)

References 26 publications

(27 reference statements)

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“…Increased screening of headgroup repulsions decreases the CMC, just as occurs with the addition of simple electrolytes to solution. Similar results were reported previously for polyelectrolytes and ionic surfactants that have the same sign of charge, 47,48 including PAA and SDS at high pH where no complexation occurs. 36 The CMC reduction caused by Na-PAA likely played an important role in the depletion force synergism.…”

Section: ■ Results and Discussionsupporting

confidence: 90%

Colloidal Depletion and Structural Force Synergism or Antagonism in Solutions of Mutually Repelling Polyelectrolytes and Ionic Surfactants

Lele

Tilton

2019

Langmuir

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Depletion and structural forces were measured between a silica sphere and plate in solutions containing sodium polyacrylate (Na-PAA) anionic polyelectrolyte and sodium dodecyl sulfate (SDS) anionic surfactant using colloidal probe atomic force microscopy, at high pH where the two species are electrostatically repelling from each other and from the silica surfaces. Measurements were performed for a range of SDS and Na-PAA concentrations to span conditions where only one of the species or both of the species would exert a detectable depletion or structural force when present in a single-component solution. In mixed solutions, conditions were identified (i) where depletion attraction was synergistically enhanced or antagonistically weakened relative to single component solutions; (ii) where the range of the depletion attraction was significantly extended and the repulsive structural force barrier was eliminated, due to simultaneous depletion of both species over different length scales; and (iii) where one species was the dominant depletant and forces in mixtures were indistinguishable from those in a single component solution of the dominant depletant. Force measurements were interpreted with the aid of pyrene solubilization assays of SDS micellization and dynamic light scattering investigation of the state of assembly of the polyelectrolyte or surfactant. The variety of colloidal force effects were attributed to ionic strength and excluded volume effects of Na-PAA on SDS micellization, ionic strength effects of SDS on Na-PAA chain clustering in solution, and ionic strength effects on the counterion contribution to polyelectrolyte osmotic pressure. While prior studies have shown that depletion force synergism occurs when polymers and surfactants form mixed complexes, this work shows that it can occur in noncomplexing mixtures as well, and it indicates the variety of effects that should be taken into account when attempting to predict forces in such mixtures.

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Section: ■ Results and Discussionsupporting

confidence: 90%

Colloidal Depletion and Structural Force Synergism or Antagonism in Solutions of Mutually Repelling Polyelectrolytes and Ionic Surfactants

Lele

Tilton

2019

Langmuir

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“…Complexes can adsorb to form surface layers with net properties that arise from a complex dependence on the balance of interactions between the polymers, surfactants, and surfaces. Architectures, adsorbed amounts, layer dimensions, net charge, rheological properties, etc., depend on how individual species chemistries contribute to net polymer–surfactant complex properties, which are generally emergent in the sense that they have nontrivial differences compared to constituents. , For example, adsorbed amounts and layer architectures sensitively depend on ionic strength for nonionic polymer–anionic surfactant complexes on negatively charged surfaces and like-charged surfactants and polymers compete for oppositely charged substrates . Adsorbed layers are sensitive to preadsorption of either the polymer or surfactant, co-adsorption of bulk complexes, or dilution of bulk complexes, which indicates the general importance of kinetic and nonequilibrium effects in layer properties …”

Section: Introductionmentioning

confidence: 99%

Synergistic Polymer–Surfactant-Complex Mediated Colloidal Interactions and Deposition

Najafi

Jerri

Valmacco

et al. 2020

ACS Appl. Mater. Interfaces

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Total internal reflection microscopy (TIRM) is used to directly, sensitively, and simultaneously measure colloidal interactions, dynamics, and deposition for a broad range of polymer–surfactant compositions. A deposition state diagram containing comprehensive information about particle interactions, trajectories, and deposition behavior is obtained for polymer–surfactant compositions covering four decades in both polymer and surfactant concentrations. Bulk polymer–surfactant phase behavior and surface properties are characterized to provide additional information to interpret mechanisms. Materials investigated include cationic acrylamide–acrylamidopropyltrimonium copolymer (AAC), sodium lauryl ether sulfate (SLES) surfactant, silica colloids, and glass microscope slides. Measured colloid–substrate interaction potentials and deposition behavior show nonmonotonic trends vs polymer–surfactant composition and appear to be synergistic in the sense that they are not easily explained as the superposition of single-component-mediated interactions. Broad findings show that at some compositions polymer–surfactant complexes mediate bridging and depletion attractions that promote colloidal deposition, whereas other compositions produce electrosteric repulsion that deters colloidal deposition. These findings illustrate mechanisms underlying colloid–surface interactions in polymer–surfactant mixtures, which are important to controlling selective colloidal deposition in multicomponent formulation applications.

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“…This correlation between cmc, α, ΔG m , N ag and type of counterion indicate that the micellization process is more spontaneous in the case of CTAT compared to CTAC and CTAB. From an application point of view, the higher binding of T − to CTA + explains the higher adsorption of CTAT onto silica [42]. It was concluded that on the silica surface, increasing the binding degree increases the cooperativity of adsorption below the bulk cmc, corresponding to a stabilization of interfacial self assembly.…”

Section: Introductionmentioning

confidence: 99%

Biopolymer Surfactant Interactions

Sreejith¹,

Nair²,

George³

2010

Biopolymers

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Specific Counterion Effects on the Competitive Co-adsorption of Polyelectrolytes and Ionic Surfactants

Cited by 27 publications

References 26 publications

Colloidal Depletion and Structural Force Synergism or Antagonism in Solutions of Mutually Repelling Polyelectrolytes and Ionic Surfactants

Colloidal Depletion and Structural Force Synergism or Antagonism in Solutions of Mutually Repelling Polyelectrolytes and Ionic Surfactants

Synergistic Polymer–Surfactant-Complex Mediated Colloidal Interactions and Deposition

Biopolymer Surfactant Interactions

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