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The unique structure and macro-rheological properties make worm-like micelles an important basic system for surfactant applications, which are widely used in many fields and have received extensive attention from researchers. In this paper, α-olefin sodium sulfonate (AOS) and cocamidopropyl betaine (CAPB) were mixed in aqueous solution to prepare viscoelastic worm-like micelles, which can be observed by cryogenic-transmission electron microscopy (cryo-TEM). It was found that the concentration of AOS and temperature have a greater impact on the formation and rheological behavior of worm-like micelles. The typical characteristics of wormlike micelles were shown in the range of AOS concentration from 0.7 wt% to 1.7 wt%; when the temperature was too high, the worm-like micelles were destroyed. In addition, the surface tension, foaming property and wettability of AOS/CAPB mixed solutions with different ratios were studied. The two show excellent synergistic effect, in which electrostatic interaction is the decisive factor, which can provide basic data for practical applications. This work further enriches the basic theoretical research on the preparation of worm-like micelles from anionic-zwitterionic surfactant systems. [ABSTRACT FROM AUTHOR]

Sodium isotridecyl polyoxyethylene ether sulfate (iC13EOnS, n = 5, 7, and 9) with different ethylene oxide (EO) numbers were synthesized by SO3 membrane sulfation process for the first time. The effects of EO number on the equilibrium surface tension, dynamic surface tension, contact angle, and alkali/salt resistance of iC13EOnS were investigated. With the increase of EO consumption, γcmc increased, but the adsorption efficiency (pC20) of surfactant increased. The increase of EO number significantly improved the alkali resistance and salt resistance of iC13EOnS. Additionally, the influence of different electrolytes and their concentrations on the IFT between iCl3EOnS solution and n-decane was also studied. At the same salt concentration, iC13EOnS with shorter EO chains exhibited lower interfacial tension. These results show that the performance of the product can be adjusted by changing the number of EO groups. The study on the relationship between EO number and the performance of iC13EOnS in this article will help to improve the application efficiency of this surfactant. [ABSTRACT FROM AUTHOR]

The interfacial tension, wettability, foam and emulsification properties of di-tetrapropylene diphenyl ether disulfonates (C12-DADS) gemini-type surfactant have been studied and compared to mono-tetrapropylene diphenyl ether disulfonates (C12-MADS) and tetrapropylene benzene sulfonates (C12-BAS). The results show that the C12-DADS have a lower interfacial activity compared to that of C12-MADS and C12-BAS. The wettability of the three surfactants decreases in the order C12-BAS > C12-DADS > C12-MADS. For foam properties, the foamability and foam stability of C12-MADS and C12-DADS is lower than that of C12-BAS. In addition, the emulsification ability increase in the order C12-DADS < C12-MADS < C12-BAS. [ABSTRACT FROM AUTHOR]

Alpha olefin sulfonates (AOS) with various alkyl chain lengths have been used to investigate the influence of alkyl chain length on the interfacial properties at air–water, liquid paraffin–water, and parafilm–water interfaces. It was found that the critical micelle concentration decreased with increasing alkyl chain length, while the efficiency of reducing surface tension was inverse relationship with alkyl chain length. The diffusion coefficient obviously reduced with an increase of surfactant concentration and alkyl chain length. The C14-16AOS shows better wettability and emulsification than C16-18AOS and C20-24AOS. For foaming properties, the foamability and foam stability dramatically decreased with increasing alkyl chain length. [ABSTRACT FROM PUBLISHER]