Aqueous, Mixed Micelles as a Means of Delivering the Hydrophobic Ionic Liquid EMIM TFSI to Graphene Oxide Surfaces.
Langmuir
; 38(1): 531-540, 2022 Jan 11.
Article
en En
| MEDLINE
| ID: mdl-34978199
ABSTRACT
Most ionic liquids (ILs) are not surface-active and cannot, alone, be directed to assemble at surfacesâdespite their potential as nonvolatile structure-directing agents and use as advanced materials in a multitude of applications. In this work, we investigate aqueous systems of common nonionic surfactants (Triton X-100 and Tween 20), which we use to solubilize 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. The resulting solution of mixed micelle leads to spontaneous adsorption of the IL/surfactant complex onto graphene oxide (GO) surfaces, forming a compact film. Adsorption isotherms generated by fluorescence labeling of the IL and surfactant phases are used to quantify the extent of adsorption. While sensitive to the GO dispersion concentration, upwards of 3 g IL/g GO adsorb under dilute conditions. Atomic force microscopy is used to show that the adsorbed layer uniformly distributes as an â¼1 nm thick coating (per GO side) as the system reaches the first plateau of a Langmuir-type isotherm. Adsorption beyond this plateau is possible but leads to thicker (>30 nm), inhomogeneous adsorbed layers. Both micellar size in solution and adsorbed layer thickness reduce upon the addition of IL to the surfactant phase, suggesting significant interactions among the materials and nonideal mixing of the components.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Langmuir
Asunto de la revista:
QUIMICA
Año:
2022
Tipo del documento:
Article
País de afiliación:
Canadá