Nonideal mixed micelles of Gemini surfactant homologues and their application as templates for mesoporous material MCM-48

The micellization properties of aqueous solutions of the mixed Gemini surfactant homologues GEM16-6-16 and GEM16-12-16 with various compositions were investigated. The measured critical micelle concentration (CMC) deviated significantly from the ideal mixing model. Good agreement was found with a nonideal mixing model, the Margules model, which has two optimal parameters, A12=−3.611A12=−3.611 and A21=−6.318A21=−6.318. It was shown that the properties of mixed micelles were not sensitive to the compositions, and most of the GEM16-12-16 molecules were aggregated into the micelles. Dynamic laser light-scattering measurements revealed that the mixed micelles had almost the same size and similar zeta potential. When the mixed micelles were used as templates, a series of highly ordered cubic MCM-48 mesoporous materials, characterized by XRD and TEM, were produced through self-assembly. The N2 adsorption–desorption measurements suggested that the pores of these materials had similar average diameters of 2.2–2.5 nm. This further demonstrated the nonideal behavior of the homologue mixture.

Graphical abstractGemini surfactant homologues GEM16-6-16 and GEM16-12-16 are nonideal mixed micelles and have template approaches for ordered mesoporous materials MCM-48.Figure optionsDownload full-size imageDownload as PowerPoint slide