New structural approach to rationalize the foam film stability of oppositely charged polyelectrolyte/surfactant mixtures

Uhlig, Martin; Löhmann, Oliver; Ruiz, Salomé Vargas; Varga, Imre; Klitzing, Regine von; Campbell, Richard A.

doi:10.1039/c9cc08470c

Cited by 20 publications

(47 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The self-assembly behavior of oppositely charged polyelectrolytes (PEs) and surfactants, leading to the formation of polyelectrolyte surfactant complexes (PESCs or SPECs), is very rich − and quite a number of structurally different arrangements such as pearl-necklace structures, clusters with densely packed micelles, − rodlike aggregates, − and uni- or multilamellar vesicles − can be obtained simply by mixing solutions of PEs and oppositely charged surfactants. PESCs are not only of fundamental scientific interest but are also of relevance for tailormade, nanostructured systems, − finding a number of applications in cosmetics, detergency, and enhanced oil recovery (EOR). ,− …”

Section: Introductionmentioning

confidence: 99%

Viscosity of Polyelectrolyte Surfactant Complexes—The Importance of the Choice of the Polyelectrolyte Seen for the Case of PDADMAC Versus JR 400

Kuzminskaya

Hoffmann²,

Clemens

et al. 2021

Macromolecules

View full text Add to dashboard Cite

Some oppositely charged polyelectrolyte (PE) surfactant mixtures show a remarkable increase in viscosity near charge equilibrium, while other very similar systems do not show any appreciable effect. The exact structural prerequisites to achieve a significant increase in viscosity are still unclear. In previous work, we investigated the structure and dynamics of oppositely charged polyelectrolyte surfactant complexes (PESCs) formed from sodium dodecylsulfate (SDS) and the cationically modified hydroxyethyl cellulose JR 400, which does enhance the viscosity around charge equilibrium enormously. Here, we study PESCs consisting of SDS and the cationic PE polydiallyldimethylammonium chloride (PDADMAC) which do not significantly increase the viscosity of solutions under similar conditions. Apparently very similar ingredients in PESCs can lead to largely different macroscopic behavior. Using small-angle neutron scattering, rheology, and neutron spin-echo spectroscopy, we gain insights into the system's mesoscopic structure and dynamics. Different from that in SDS/JR 400, no intermixed aggregates are formed but instead a cylindrical core−shell structure. In it, the PDADMAC is much less strongly bound and possesses much higher dynamics which explains the much lower viscosity.

show abstract

Section: Introductionmentioning

confidence: 99%

Viscosity of Polyelectrolyte Surfactant Complexes—The Importance of the Choice of the Polyelectrolyte Seen for the Case of PDADMAC Versus JR 400

Kuzminskaya

Hoffmann²,

Clemens

et al. 2021

Macromolecules

View full text Add to dashboard Cite

show abstract

“…Accompanying such phase separation, is the formation of nanostructures with different morphologies and organisation, including soluble complexes, precipitates, gels and liquid crystalline phases [ 5,6 ]. Complex coacervation is further complicated by the presence of interfaces [ [7][8][9][10], but the continued focus on studying coacervation is driven by its relevance to many and diverse applications of formulated, nanostructured systems [ [11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Interaction of Low Molecular Weight Poly(diallyldimethylammonium chloride) and Sodium Dodecyl Sulfate in Low Surfactant–Polyelectrolyte Ratio, Salt-Free Solutions

et al. 2020

View full text Add to dashboard Cite

Coacervation is widely used in formulations to induce a beneficial character to the formulation but non-equilibrium effects are often manifest. Electrophoretic (eNMR), pulsedgradient spin-echo NMR (PGSE-NMR) and small-angle neutron scattering (SANS) have been used to quantify the interaction between low molecular cationic poly(diallyldimethylammonium chloride) (PDADMAC) and the anionic surfactant sodium dodecylsulphate (SDS) in aqueous solution as a model for the precursor state to such nonequilibrium processes. The NMR data show that within the low surfactant concentration onephase region, an increasing surfactant concentration leads to a reduction in the charge on the polymer and a collapse of its solution conformation, attaining minimum values coincident with the macroscopic phase separation boundary. Interpretation of the scattering data reveals how the rod-like polymer changes over the same surfactant concentration window, with no discernible fingerprint of micellar type aggregates, rather the emergence of disc-like and lamellar structures. At the highest surfactant concentration, the emergence of a weak Bragg peak in both the polymer and surfactant scattering suggest these pre-cursor disc and lamellar structures evolve into paracrystalline stacks which ultimately phase separate. Addition of the non-ionic surfactant hexa(ethylene oxide) dodecyl ether (C12E6) to the system seems to have little effect on the PDADMAC/SDS interaction as determined by NMR, merely displacing the

show abstract

“…Having in mind the almost irreversible adsorption of proteins at liquid interfaces and the pronounced viscoelastic behavior of the corresponding interfacial layers, the phenomenon of rupture of protein black films could obey other mechanisms. Very recently, it was shown for mixed polymer/surfactant aqueous systems that resolving the molecular structure of the adsorbed interfacial layers is a vital step for revealing the surface forces operative in the corresponding foam films, and thus, the film stabilization mechanism [74]. Therefore, looking deeper into the structure of protein layers would give more insight into the stability of protein black films.…”

mentioning

confidence: 99%

β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 4. Impact on the Stability of Foam Films and Foams

et al. 2020

View full text Add to dashboard Cite

The complexity and high sensitivity of proteins to environmental factors give rise to a multitude of variables, which affect the stabilization mechanisms in protein foams. Interfacial and foaming properties of proteins have been widely studied, but the reported unique effect of pH, which can be of great interest to applications, has been investigated to a lesser extent. In this paper, we focus on the impact of pH on the stability of black foam films and corresponding foams obtained from solutions of a model globular protein—the whey β-lactoglobulin (BLG). Foam stability was analyzed utilizing three characteristic parameters (deviation time, transition time and half-lifetime) for monitoring the foam decay, while foam film stability was measured in terms of the critical disjoining pressure of film rupture. We attempt to explain correlations between the macroscopic properties of a foam system and those of its major building blocks (foam films and interfaces), and thus, to identify structure-property relationships in foam. Good correlations were found between the stabilities of black foam films and foams, while relations to the properties of adsorption layers appeared to be intricate. That is because pH-dependent interfacial properties of proteins usually exhibit an extremum around the isoelectric point (pI), but the stability of BLG foam films increases with increasing pH (3–7), which is well reflected in the foam stability. We discuss the possible reasons behind these intriguingly different behaviors on the basis of pH-induced changes in the molecular properties of BLG, which seem to be determining the mechanism of film rupture at the critical disjoining pressure.

show abstract

New structural approach to rationalize the foam film stability of oppositely charged polyelectrolyte/surfactant mixtures

Abstract: The foam film stability of polyelectrolyte/surfactant mixtures is rationalized using structural data from neutron reflectometry for the first time.

Cited by 20 publications

References 35 publications

Viscosity of Polyelectrolyte Surfactant Complexes—The Importance of the Choice of the Polyelectrolyte Seen for the Case of PDADMAC Versus JR 400

Viscosity of Polyelectrolyte Surfactant Complexes—The Importance of the Choice of the Polyelectrolyte Seen for the Case of PDADMAC Versus JR 400

Interaction of Low Molecular Weight Poly(diallyldimethylammonium chloride) and Sodium Dodecyl Sulfate in Low Surfactant–Polyelectrolyte Ratio, Salt-Free Solutions

β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 4. Impact on the Stability of Foam Films and Foams

Contact Info

Product

Resources

About