Ionogels of pseudogemini supra-amphiphiles in ethylammonium nitrate: Structures and properties.

Thermoreversible ionogels formed by pseudogemini surfactants were prepared in protic ionic liquid, ethylammonium nitrate (EAN). Gemini-type supra-amphiphiles were formed by single-chain surfactants and bola-type molecules in a 2:1M ratio. The structures of aggregates including polymorphous lamellar structures and fibrous networks constituted by multilayer lamellae were determined by optical microscopy observations, transmission electron microscopy (TEM) observations, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) measurements. The mechanism of molecular arrangement in aggregates was proposed. Transformation temperatures of samples which are closely related to the stability of well-ordered molecules in aggregates, as well as the rheological properties of ionogels were investigated systematically. The work affords a new way to construct ionogel by using the supramolecular self-assembly of pseudogemini-type molecules, and brings new ideas for the future construction of ionogels.