Self‐Assembly Behaviors of Anionic–Cationic Binary Surfactant Systems in Poly(ethylene glycol) 200

Abstract

The self‐assembly behaviors of mixtures of sodium bis(2‐ethylhexyl) sulfosuccinate (AOT) and didodecyl dimethylammonium bromide (DDAB) in polyethylene glycol 200 (PEG 200) and in water were investigated by surface tension, conductivity, steady‐state fluorescence and dynamic light scattering (DLS) methods. The results show that the oppositely charged binary surfactant system can form micelles in PEG 200; the critical micellization concentration (CMC) decreases for the binary system versus those of either surfactant alone. Although there is no charge screening in the PEG 200 system, the CMC values significantly increase and the system does not precipitate or show turbidity at any proportion of AOT to DDAB, while a multiphase composition gap exists in water due to the strong electrostatic attraction. It is speculated that the weak polarity of PEG 200, the decreased solvophobic interaction between the alkyl chain and PEG 200, and the loose structure of the resulting micelles might explain the experimental phenomena. Observed from the values of the interaction parameter, it is found that there are a strong attractive interaction and a synergistic effect between AOT and DDAB in aqueous solution, in comparison, the synergy between them in PEG 200 is very weak.

Study on polyetheretherketone prepreg manufactured by aqueous system of powder impregnation

“…It can be seen that with the increases of AOT concentration, the surface tension of H 2 O solution decreases and tends to be stable, with a value of 28 mN/m, its CMC is 1.23 g/L, that is, 2.77 mM, which consists with the test results of. [ 29,30 ] The Triton's stable value is 30 mN/m, the CMC is 0.15 g/L, that is, 0.29 mM, which consists with the test results of Reference [31]. The A25's stable value is 39 mN/m, the CMC is 0.4 g/L, that is, 1.32 mM.…”

Mixtures of antidepressant amphiphilic drug imipramine hydrochloride and anionic surfactant: Micellar and thermodynamic investigation

“…According to regular solution theory, for a particular system, β m should remain independent of composition, which is frequently not realized in practice. Herein, the parameter obtained to be composition‐dependent is related to previous mixed systems of cationic and anionic amphiphiles …”

Self-Assembly and Thermodynamic Properties of Dodecyldimethylethylammonium Bromide in Ethylene Glycol or Ethylene Glycol Oligomers and Water Mixed Solutions

“…Reports have shown that short-chain alcohols (methanol, ethanol, and butanol), polyols (ethylene glycol, glycerol, and polyethylene glycol), and dimethylformamide are commonly used as preferred additives or solvents. − The micellization behavior of ionic surfactants in mixed solvents has been extensively studied. − Glycols produce solvophobic effects, which enhance cmc of the surfactant compared to pure water as a solvent . This can even resolve issues regarding precipitation appearing in anion/cation mixed surfactant system, as described in our previous study . Furthermore, polyethylene glycols (PEGs) with different molecular weights differ in physical and chemical properties because of the degree of polymerization and chain length .…”

“…In the case of ionic surfactant solutions, the conductivity curve shows a turning point at cmc, which is determined by the intersection of two straight lines. 36 If the conductivity curve displays a straight line with no interruption in slope, such as the AOT/H 2 O system, 24 no micellization or complete ionization of the counterions occurs.…”

“…23 This can even resolve issues regarding precipitation appearing in anion/ cation mixed surfactant system, as described in our previous study. 24 Furthermore, polyethylene glycols (PEGs) with different molecular weights differ in physical and chemical properties because of the degree of polymerization and chain length. 25 As important chemical products and intermediates, ethylene glycol (EG) or PEG oligomers are the first choice in mixed solvent research because of their large excessive sales in China market and that they are nontoxic and non-irritating.…”