scholarly journals Surfactant-Switched Positive/Negative Electrorheological Effect in Tungsten Oxide Suspensions

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3348 ◽  
Author(s):  
Alexander V. Agafonov ◽  
Anton S. Kraev ◽  
Tatiana V. Kusova ◽  
Olga L. Evdokimova ◽  
Olga S. Ivanova ◽  
...  
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Electric Field ◽  
Tungsten Oxide ◽  
Electric Fields ◽  
Silicone Oil ◽  
Sodium Dodecyl ◽  
Electrorheological Effect ◽  
Multiplicative Effect ◽  
Dodecyl Sulfate ◽  
Visualization Experiments

The electrorheological (ER) effect was experimentally observed in dielectric suspensions containing tungsten oxide (WO3) modified with surfactant molecules (sodium dodecyl sulfate (SDS) and dodecylamine (DDA)) in electric fields up to several kilovolts per millimeter. The dielectric properties of WO3 suspensions in silicone oil were analyzed, depending on the frequency of the electric field, in the range from 25 to 106 Hz. Unmodified WO3 suspensions, as well as suspensions modified with sodium dodecyl sulfate, were shown to exhibit a positive electrorheological effect, whereas suspensions modified with dodecylamine demonstrated a negative electrorheological effect. The quantitative characteristics of the negative electrorheological effect in the strain–compression and shear regimes were obtained for the first time. Visualization experiments were performed to see the chain structures formed by WO3 particles modified with sodium dodecyl sulfate, as well as for dynamic electroconvection in electrorheological fluids containing WO3 modified with dodecylamine. The negative electrorheological effect was shown to be associated with the processes of phase separation in the electric field, which led to a multiplicative effect and a strong electroconvection of the suspension at field strengths above 1 kV/mm.

scholarly journals Active control of boundary lubrication of ceramic tribo-pairs in sodium dodecyl sulfate aqueous solutions

2021 ◽  
Author(s):  
Yonggang Meng ◽  
Chenxu Liu ◽  
Jingbo Fang ◽  
Xiangli Wen ◽  
Yu Tian
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Electric Field ◽  
Aqueous Solutions ◽  
Active Control ◽  
Boundary Lubrication ◽  
Sodium Dodecyl ◽  
Electrode System ◽  
Adsorption Model ◽  
Active Control Of Friction ◽  
Dodecyl Sulfate

Abstract The objective of the study is to actively control friction between engineering ceramics in underwater applications. By designing a proper electrode system and applying an external electric field, the active control of friction between Al2O3 plate and ZrO2 ball in sodium dodecyl sulfate (SDS) aqueous solutions has been realized, which is different from the previous studies of potential controlled boundary lubrication where at least one part of tribo-pairs is a conductor. Reversible change of friction coefficient has been observed in the range from 0.12 to 0.35. An indirect electric field-assisted adsorption model has been proposed to explain the observed phenomena. The addition of inorganic salts containing counterions to the SDS solution or increasing the concentration of SDS can shorten the response time of friction to the variation of the applied electric field by facilitating the formation of SDS micelles. This opens a new way to realize the active control of friction for insulative tribo-pairs without corrosion.

Solubility and adsorption behaviors of chlorophenols in the presence of surfactant

1997 ◽  
Vol 35 (7) ◽  
pp. 123-130 ◽  
Author(s):  
J. C. Liu ◽  
P. S. Chang
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Critical Micelle Concentration ◽  
Sodium Dodecyl ◽  
Adsorption Behaviors ◽  
Brij 35 ◽  
Important Index ◽  
Dodecyl Sulfate ◽  
Triton X

The solubility of chlorophenols as affected by surfactant was investigated. Three kinds of surfactant, sodium dodecyl sulfate, Triton X-100, and Brij 35, were utilized. The solubilization of chlorophenols by surfactant follows the order of 2,4,6-trichlorophenol > 2,4-dichlorophenol > 2,6-dichlorophenol > 2-chlorophenol; and the critical micelle concentration is an important index. The adsorption reactions of 2,4-dichlorophenol and 2,4,6- trichlorophenol onto hydrous montmorillonite in the presence of surfactant were examined. The presence of surfactant decreased the adsorption of chlorophenols significantly. The roles of hydrophobicity of chlorophenols in solubilization and adsorption behaviors are discussed.

Different submicellar solubilization mechanisms revealed by 1H NMR and 2D diffusion ordered spectroscopy (DOSY)

2020 ◽  
Vol 22 (19) ◽  
pp. 11075-11085
Author(s):  
Mengjian Wu ◽  
Zhaoxia Wu ◽  
Shangwu Ding ◽  
Zhong Chen ◽  
Xiaohong Cui
Keyword(s):  
Nmr Spectroscopy ◽  
Sodium Dodecyl Sulfate ◽  
1H Nmr ◽  
Sodium Dodecyl ◽  
Butyl Methacrylate ◽  
H Nmr ◽  
Molecular Scale ◽  
Two Systems ◽  
Dodecyl Sulfate ◽  
Triton X

Different submicellar solubilization mechanisms of two systems, Triton X-100/tetradecane and sodium dodecyl sulfate (SDS)/butyl methacrylate, are revealed on the molecular scale by 1H NMR spectroscopy and 2D diffusion ordered spectroscopy (DOSY).

Sign in / Sign up

Export Citation Format

Share Document