Dilational rheological properties of sulphobetaines at the water–decane interface: Effect of hydrophobic group

Effect of Added Tetraalkylammonium Counterions on the Dilational Rheological Behaviors of N-Cocoyl Glycinate

“…K e y w o r d s : t e t r a a l k y l a m m o n i u m , a m i n o a c i d -b a s e d s u r f a c t a n t , i n t e r f a c i a l t e n s i o n , i n t e r f a c i a l d i l a t i o n a l r h e o l o g y , i o n s p e c i f i c e f f e c t s increasing their adsorption through electrostatic interaction with counterions in added electrolytes 12 . Tetraalkylammonium ions are a class of kosmotropic cations, and their effects on surfactants are even more pronounced 12 17 .…”

Influence of CTAB-Grafted Faujasite Nanoparticles on the Dynamic Interfacial Tension of Oil/Water Systems

“…It can be concluded from the figure that increasing the concentration of the nanofluids up to certain concentration levels (∼10 ppm) led to enhancing the elasticity in the low-frequency range. Then, the elasticity at the higher concentrations tended to reach an apparent plateau. , …”

“…The surface viscoelastic behavior of the o/w interface is strongly affected by the molecular structure of the adsorbed layer at the interface and plays a major role in the stability of water–oil emulsions. , Generally, the variation of surfactant concentration due to the presence of a high bulk concentration of surfactant has distinctive effects on interfacial dilational characteristics. , On the one hand, increasing the surfactant concentration might lead to (i) a higher interfacial tension gradient corresponding to the same interfacial deform, which increases the dilational modulus, or (ii) enhancing the molecular exchange of surfactant between the bulk and interface. , On the other hand, diffusion of surfactant molecules from the bulk to the interface might allow the decrease of the interfacial tension gradient, which creates a decrease in the dilational modulus. , Thus, the variation of the dilational properties at certain oscillation frequencies could impact the characteristic of the interfacial adsorption film. , Accordingly, oscillation frequency measurements at a range from 0.02 to 0.15 Hz during different stages of drop compression in the o/w interface were carried out using different concentrations of FAU–0.09CTAB nanofluid, as represented in Figure . It can be concluded from the figure that increasing the concentration of the nanofluids up to certain concentration levels (∼10 ppm) led to enhancing the elasticity in the low-frequency range.…”

“…In principle, the estimation of ε can be obtained from the sinusoidal oscillatory variation of the interfacial tension (Δγ) and the interfacial area (Δ A ), as established in eq , where γ and A are the IFT (mN/m) and interfacial area (m 2 ), respectively. Furthermore, these small and fast periodic axisymmetric droplet area compressions and expansions disturb the monolayer equilibrium and, thus, induce the appearance of relaxation processes, such as diffusion exchange between the surface layer and the bulk solution or molecular rearrangements within the layer, which eventually produce phase differences between Δ A and Δγ . In that case, ε can also be mathematically expressed as the summation of a real part, which is known as the dilational elasticity, ε d , and an imaginary part, which is related to the interfacial viscosity η d (eq ) , where ω is the oscillation angular frequency.…”

A comparative study on the interface tension and interface dilational rheological properties of three sodiumN-acyl aromatic amino acid surfactants

“…[4][5][6][7][8][9] Practical application has conrmed that interface dilational rheology is simple and powerful and it has been extensively used in molecular surface interface interactions and their aggregates. [10][11][12][13] Current research on the phenomenon of interface rheology mostly focuses on surfactant solution systems in which the rheological properties are affected by the hydrophobic alkyl chain length. For example, Li et al investigated the dynamic dilational viscoelastic properties of N-2-(phenoxy)tetradecanolytaurinate (12+B-T) and N-2-(4-ethylphenoxy)tetradecanolytaurinate (12+2B-T), as well as the inuence of time, dilational frequency, and molar concentration on the dilational modulus.…”