Abstract
The composition of the adsorbed film and the excess Gibbs energy of adsorption $$ {\widehat{g}}^{\mathrm{H},\mathrm{E}} $$ were evaluated from thermodynamic analysis of surface tensions for the 1-decyl-3-methylimidazoulium bromide (C10mimBr)–tetraethylene glycol monooctyl ether (C8E4) and 1-decyl-3-methyl-imidazolium tetrafluorobrorate (C10mimBF4)–C8E4 systems, where the counter anion of imidazolium salts is different from each other. The higher miscibility of two components compared to an ideal mixing and thus negative $$ {\widehat{g}}^{\mathrm{H},\mathrm{E}} $$ were observed in the former, which comes from the ion–dipole interaction between imidazolium cation and the oxyethylene group of C8E4. On the other hand, the lower miscibility and thus positive $$ {\widehat{g}}^{\mathrm{H},\mathrm{E}} $$ were observed for the latter. Such differences were attributed to that BF4 − forms two hydrogen bonds and has stronger affinity with the cationic head group of C10mim+ than Br−. This results in that the ion–dipole interaction between C8E4 and C10mim+ cation is diminished in the C10mimBF4–C8E4 system.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
