Interaction between the added long-chain ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate and Triton X-100 in aqueous solutions

The effect of added long-chain ionic liquid 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12mim][BF4]) on Triton X-100 aqueous solution has been studied by surface tension measurements, electrical conductivity, 1H NMR and FF-TEM technologies. The surface tension measurements revealed that the ionic liquid [C12mim][BF4] can increase the critical micelle concentration (CMC) of Triton X-100 dramatically, suggesting that it is not conducive to the micelle formation of Triton X-100. The electrical conductivity results showed very interesting features. The electrical conductivity curves of Triton X-100 are very different while the concentration of added [C12mim][BF4] is below and upon its CMC. The 1H NMR data demonstrated that there are hydrogen-bond interactions between the imidazolium cation of [C12mim][BF4] and the hydrophilic PEO groups of Triton X-100 and hydrophobic interactions between the dodecyl chain of the imidazolium cation and the hydrophobic chain with phenyl of Triton X-100. Through these two kinds of interactions, [C12mim][BF4] and Triton X-100 can form mixed micelles.

Hydrogen-bond interactions between the imidazolium cation of [C12mim][BF4] and the hydrophilic PEO groups of Triton X-100 and hydrophobic interactions between the dodecyl chain of the imidazolium cation and the hydrophobic chain of Triton X-100 occur when Triton X-100 is added into [C12mim][BF4] aqueous solutions. Through these two kinds of interactions, [C12mim][BF4] and Triton X-100 can form mixed micelles.Figure optionsDownload as PowerPoint slideResearch highlights▶ The physicochemical properties of Triton X-100 aqueous solutions can be modified by addition of long-chain ionic liquid [C12mim][BF4]. ▶ The effect of added ionic liquid [C12mim][BF4] on the micelle formation of Triton X-100 results from hydrogen-bond interactions and hydrophobic interactions between them. ▶ The change of the morphology of the aggregates formed by [C12mim][BF4]/Triton X-100 is demonstrated by FF-TEM.