Interfacial dilational properties of tri-substituted alkyl benzene sulfonates at air/water and decane/water interfaces

Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ldis. interface during the molecules exchange between interface and bulk phase, has been extensively studied in recent years and played a significant role in many research fields, such as foam and emulsion stability. [1,2] In general, interfacial rheology is classified to dilational rheology and shear rheology according to the interface modification under different external mechanical perturbation. Two kinds of interfacial rheology coexisted when the interfacial film was compressed and expanded. The dilational modulus is several orders of magnitude than shear modulus, therefore, the contribution Hydroxyl sulfobetaines with hexadecyl-, octadecyl-hydrophobic chain and an industrial product hydroxyl sulfobetaine were synthesized from analytical-grade and industrial-grade tertiary amine, respectively. The dilational properties and surface tension of the three surfactants at the water-air interface were investigated by drop shape analysis and ring method. The influences of oscillating frequency and bulk concentration on dilational properties were explored. The experimental results show that the dilational module of octadecyl-hydroxyl sulfobetaine was higher than hexadecyl hydroxyl sulfobetaine and the dilational elastic component of the three surfactants were higher than dilational viscous component. Furthermore, the dilational elastic component of mixed surfactant system shows two maxima in a lower concentration than that of single surfactant system. As a result, the surface tension of mixed surfactant system reaches to minimum value in a lower concentration compared with single surfactant system. The simulation results show that the hydrophobic chains in the mixed betaine solution were more curled than in single-component betaine solution ascribed to stronger interaction among different hydrophobic chains, resulting to a more compact interfacial film.

Section: Results and Discussion Effect Of Frequency On Dilational Elamentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Dilational Rheology at Air/Water Interface and Molecular Dynamics Simulation Research of Hydroxyl Sulfobetaine Surfactant

Chen

Zhang

Jiang

et al. 2014

“…Therefore, the dilational viscosity may run through a maximum with increasing concentration. [34] With respect to low molecular weight surfactants, it is generally believed that there are two kinds of relaxation processes. One is diffusion process between the interface and the bulk, the other is relaxation processes at the interface, such as molecular reorientation or rearrangement.…”

Section: Surface and Interfacial Dilational Viscosity For C 8 E 3 Nc mentioning

confidence: 99%

“…These are different from tri-substituted alkyl benzene sulfonates, whose interfacial dilational data are much smaller than those surface data. [34] It could speculate that the peculiarities of dilational properties between water-air and water-decane interface may be attributed to the structures of the zwitterionic gemini surfactants, in which one ionic group is negative and the other is cationic. That is, the different sign electric charge results in Coulombic attraction, which could be intermolecular and intramolecular attraction.…”

mentioning

confidence: 99%

Dilational Viscoelasticity of the Zwitterionic Gemini Surfactants with Polyoxyethylene Spacers at the Interfaces

Feng

Liu

Zhang

et al. 2011

Self Cite

The dilational viscoelasticity of zwitterionic gemini surfactants C 8 E x NC 12 with polyoxyethylene spacers at the water-air and water-decane interfaces were investigated by oscillating barriers method. The experiments were carried out at different concentrations with an accessible frequency range of 0.005 to 0.1 Hz. Interfacial tension relaxation method was employed to obtain dilational parameters in a reasonably broad frequency range. Experimental results show that the values of dilational elasticity and viscosity of C 8 E x NC 12 are larger than those of common nonionic surfactants, such as T Â 100, and the dilational viscoelasticity at the water-decane is close to that at the water-air interface on the whole . The results may be attributed to Coulombic attraction, and the possible schematic diagrams of adsorbed molecules with different polyoxyethylene spacers at the water-air and water-decane interfaces are proposed. We also analyzed C 8 E x NC 12 from the results of relaxation experiments and Cole-Cole plots.

“…In recent years, progress in interfacial rheometrical instrumentation has lead to an increase in the quality and availability of dilational rheological experiment. [24][25][26][27][28][29][30] A change in interfacial composition will lead to a change in interfacial rheological properties of adsorbed layers. In the present work, we have carried out dilational experiments on hydrophobically modified partly hydrolyzed polyacrylamide HMPAM (at a constant concentration of 1500 mg Á L À1 ) in the absence or presence of various amounts of anionic surfactants with the additions of different types of salt (NaCl, MgCl 2 , CaCl 2 ).…”

Section: Introductionmentioning

confidence: 99%

Interfacial Dilational Properties of Hydrophobically Modified Partly Hydrolyzed Polyacrylamide and Anionic Surfactants at the Water-Decane Interface

2010

The dilational viscoelastic properties of hydrophobically modified partly hydrolyzed polyacrylamide and anionic surfactants (4,5-diheptyl-2-propylbenzene sulfonate and gemini surfactant C 12 COONa-p-C 9 SO 3 Na) in the absence or presence of electrolyte have been investigated at the decane-water interface by means of longitudinal method and the interfacial tension relaxation method. Experimental results show that at low surfactant concentration, the increase of the dilational modulus by the addition of surfactant molecules at low frequency might be explained by the mix-adsorption of the polymer chains and surfactant molecules. At the same time, polymer chain could sharply decrease the dilational modulus of surfactant film mainly due to the weakening of the strong interactions among long alkyl chains in surfactant molecules. At high surfactant concentration, the addition of surfactant molecules can decrease the dilational modulus of polymer solution due to the fast process involving in the exchange of surfactant molecules between the interface and the mixed complex formed by surfactant molecules and hydrophobic microdomains. The added electrolyte, which results in screening of electrostatic interactions between the ionized groups, generally increases the frequency dependence of the interfacial dilational modulus. The data obtained on the relaxation processes via interfacial tension relaxation measurements can explain the results from oscillating barriers measurements very well.