Charge and Electrical Double Layer Formation in a Nonpolar Solvent Using a Nonionic Surfactant

Abstract

In this work, we study the charge formation and the characteristics of the electrical double layer in a nonpolar medium using electrical impedance spectroscopy. To stabilize the free ionic species, a nonionic surfactant is added to the system. The conductivity and permittivity of the medium are obtained from high-to medium-frequency impedance data. Based on the correlation between (viscosity-adjusted) conductivity and surfactant concentration, we conclude that charge formation occurs due to a disproportionation mechanism. We accordingly estimate the concentration of the charge carriers in the sample and the Debye length of the diffuse double layer. The capacitance of the electrical double layer can be extracted from the low-frequency impedance data. We use this data to calculate the electrode distance of an equivalent parallel plate capacitor. It is found that this distance is on the order of magnitude of Angstroms, indicating that the measured electrical double layer capacitance is in fact the Stern layer capacitance.

Effect of a Surfactant Mixture on Coalescence Occurring in Concentrated Emulsions: The Hole Nucleation Theory Revisited

“…Furthermore, we have checked that all of the results below weakly depend on the variation of these bending moduli. For our quaternary system made of Span 80, Tween 20, water, and dodecane, we take b 0 ≃ 1.7 nm, , κ = 0.59 k B T , and κ̅ = −0.58 k B T . The only remaining variable in our problem is therefore the interfacial tension γ.…”

DropBlot: single-cell western blotting of chemically fixed cancer cells

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Modulation of Surface Charge by Mediating Surface Chemical Structures in Nonpolar Solvents with Nonionic Surfactant Used as Charge Additives

“…Therefore, the surface charging in nonpolar solvents cannot be achieved through ion dissociation or ion adsorption. However, it is still possible to generate and stabilize charged ions in nonpolar solvents by a variety of methods, such as surfactant-induced charging of surfaces. , …”

“…However, it is still possible to generate and stabilize charged ions in nonpolar solvents by a variety of methods, such as surfactantinduced charging of surfaces. 7,8 Surface can be charged in nonpolar solvents if surfactants are used as charge control additives. In this process, the reverse micelles formed by the aggregation of surfactant molecules play an important role in surface charging.…”