Strong synergistic effect of cationic hydrocarbon surfactant and novel nonionic tri-block short-chain fluorocarbon surfactant mixtures on surface activity, wettability and solubilization

Abstract

Abstract

Mixing hydrocarbon surfactants with fluorocarbon surfactants is still an important strategy to improve the economic benefits and performances of fluorocarbon surfactants and expand their range of application. Herein, we prepared a novel kind of hydrocarbon-fluorocarbon surfactant mixtures via mixing a cationic surfactant, cetyltrimethylammonium bromide (CTAB), with a tri-block nonionic short-chain fluorocarbon surfactant (F₉EG₁₃F₉) in aqueous solution. The results showed that adding a small CTAB amount to F₉EG₁₃F₉ (the molar fraction of CTAB in the mixture (x ₁) was 0.2) could greatly reduce its critical micelle concentrations (cmc) from 0.408 mmol/L to 0.191 mmol/L. At this x ₁, the contact angle of the mixture was the minimum (57.7 °) at 100 s on polytetrafluoroethylene film, which was even lower than that of F₉EG₁₃F₉. Besides, CTAB/F₉EG₁₃F₉ mixtures possessed better colloidal stability and solubilization ability toward hydrophobic dye (Sudan І) than F₉EG₁₃F₉. The outstanding performances of binary surfactant mixtures benefited from the non-ideal mixing and strong synergistic effect evidence that CTAB/F₉EG₁₃F₉ surfactant mixtures could be used in practical applications instead of individual F₉EG₁₃F₉, thereby reducing the used cost of F₉EG₁₃F₉.

Graphical abstract

Funding

National Natural Science Foundation of China(No. 22078207)

Sichuan Science and Technology Program(2021ZHCG0042)

Fundamental Research Funds for the Central Universities