Supramolecular self-assembly is a convenient tool for fine-tuning of thin-film structure and properties through adjustment of intermolecular interactions. Designing an appropriate chemical structure together with selecting an optimal sample preparation protocol allows organizing wedge-shaped supramolecular building blocks in various mesophases with 1D-, 2D- or 3D-ordered systems of ion-conducting channels. The control of the topology of ion channels is crucial for the development of next-generation ion conductors. Here we study an amphiphilic wedge-shaped molecule bearing a sulfonate group at the extremity of a bulky aromatic moiety and having a pyridinium counter-ion. This compound exhibits complex structural transitions as a function of temperature and under the action of solvent vapors. The evolution of the thin-film structure was explored in situ by combination of polarizing optical microscopy and grazing-incidence small-angle X-ray scattering. In vapors of alcohols at room temperature, the thin films reveal reversible monoclinic columnar-to-lamellar phase transition. During heating in the swollen state, the films transform to a gyroid phase with 3D bicontinuous networks of ion channels. In the presence of solvent vapors, the opposite transition to lamellar phase takes place at room temperature. Upon this treatment, the gyroid phase is stable over a wide temperature range, which opens a way to fabricate efficient ion conducting materials.
展开▼
