ABSTRACT
The interfacial behavior of β-casein and BSA solutions have been investigated in the presence of imidazolium-based ionic liquid surfactant ([C14mim]Br) at the decane/water interface with the oscillating the drop and interfacial tension relaxation measurements. Both the electrostatic and the hydrophobic interaction between protein and [C14mim]Br played crucial roles as [C14mim]Br concentration increases. Furthermore, it was found that the dilational rheology parameters provided information of the adsorbed layers structure, and the dynamics properties of the adsorbed layers depend on the bulk [C14mim]Br concentration. Moreover, with the concentration of [C14mim]Br increasing, β-casein in the interfacial layer was subject to conformational changes where it gave space to [C14mim]Br molecules in the form of co-adsorb; for BSA/[C14mim]Br solutions, the globule protein BSA deformed and then co-adsorb with [C14mim]Br molecules at the decane/water interface. These results will contribute to elucidation of the influence of the surfactant on the different structure proteins and the wide applications of protein/surfactant systems in practice.
GRAPHICAL ABSTRACT
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