Fueling the future: A fibrillar network (red fibers, see figure) is formed from an activated building block (red), which is obtained from a synthetic gelator (blue) in a dissipative self‐assembly process that is fueled by an alkylating agent. When the available energy is depleted, the system reverts to its thermodynamic equilibrium, that is, an isotropic solution.

Chirality seems to be intimately associated with the growth and stability of self-assembled fibrillar networks and with the most common macroscopic property of these networks, which is the thermoreversible gelation of the solvent. The presence and the relative configurations of stereogenic centers in the structure of a small molecule gelator are generally (but not always) observed to be critical to its ability to form gels. Symmetry considerations of chiral molecular packing provide thermodynamic and kinetic arguments that may explain why chirality favors fiber growth. Additionally, molecular chirality is sometimes expressed at a scale of nanometers or micrometers and gives rise to twisted or coiled fiber structures that are readily observable by microscopic techniques. These chiral fiber morphologies have already found some applications as templates for helical protein crystallization or for the growth of chiral inorganic replicas. The chiroptical properties of assembled chiral molecules, e.g., circular dichroism, allow monitoring of aggregation and may sometimes give insights into molecular packing. But determining chiral molecular arrangements in the fibers remains a challenge and requires the use of multiple techniques.

Amphiphile supramolecular assemblies result from the cooperative effects of multiple weak interactions between a large number of subcomponents. As a result, prediction of and control over the morphologies of such assemblies remains difficult to achieve. Here, we described the fine-tuning of the shape, size, and morphology transitions of twisted and helical membranes formed by non-chiral dicationic n-2-n gemini amphiphiles complexed with chiral tartrate anions. We have reported that such systems express the chirality of the tartrate components at a supramolecular level and that the mechanism of the chiral induction by counterions involves specific anion cation recognition and the induction of conformationally labile chirality in the cations. Here, we demonstrate that the morphologies and dimensions of twisted and helical ribbons, as well as tubules, can be controlled and that interconversion between these structures can be induced upon modifying temperature, upon introducing small amounts of additives, or slightly modifying molecular structure. Specifically, electron microscopy, IR spectroscopy, and small-angle X-ray scattering show that (i) varying the hydrophobic chain length or adding gemini having bromide counterions (1%) or the opposite enantiomer (10%) leads to an increase of the diameter of membrane tubules from 33 to 48.5 nm; (ii) further addition (1.5%) of gemini bromide or a slight increase in temperature induces a transition from tubules to twisted ribbons; (iii) the twist pitch of the ribbons can be continuously tuned by varying enantiomeric excess; and (iv) it was also observed that the morphologies of these ribbons much evolve with time. Such unprecedented observations over easy tuning of the chiral supramolecular structures are clearly related to the original feature that the induction of chirality is solely due the counterions, which are much more mobile than the amphiphiles.