Abstract
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.
Disclosure statement
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.