Synthesis and surface activity of phenylselenide-1-undecyl trimthylamonium bromide

Abstract

Selenium-containing surfactant has aroused considerable attention due to its unique chemical properties, especially environmental sensitivity. Here we synthesized a Se-containing cationic surfactant, phenylselenide-1-undecyl trimethylammonium bromide (PSeTAB), and studied its Krafft temperature (T_K), equilibrium/dynamic surface tension, and foam properties. The results showed that with the addition of H₂O₂, the hydrophobic selenide group in PSeTAB was oxidized to a hydrophilic selenoxide structure, providing another polar head, and thus producing a larger geometry. As a result, PSeTAB-Ox exhibited a stronger affinity to water, lowering the T_K, tendency toward micellization and adsorption (higher cmc, less negative $\Delta G_m^o$ and $\Delta G_{\mathit{ads}}^o$), dynamic surface activity (smaller $R_{1/2}$) and diffusion coefficients, compared to PSeTAB. Macroscopically, PSeTAB showed relatively good foaming properties, while PSeTAB-Ox has hardly any foaming ability.

Graphical Abstract

Keywords:

• Cationic surfactant
• equilibrium/dynamic surface tension
• foam
• Krafft temperature
• selenium-containing

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China (21474114) and the Central University Basic Research Fund of Southwest Minzu University (2018NZD08).