Adinela Cazacu

Dynamic hybrid materials for constitutional self-instructed membranes.

Constitutional self-instructed membranes were developed and used for mimicking the adaptive structural functionality of natural ion-channel systems. These membranes are based on dynamic hybrid materials in which the functional self-organized macrocycles are reversibly connected with the inorganic silica through hydrophobic noncovalent interactions. Supramolecular columnar ion-channel architectures can be generated by reversible confinement within scaffolding hydrophobic silica mesopores. They can be structurally determined by using X-ray diffraction and morphologically tuned by alkali-salts templating. From the conceptual point of view, these membranes express a synergistic adaptive behavior: the simultaneous binding of the fittest cation and its anion would be a case of “homotropic allosteric interactions,” because in time it increases the transport efficiency of the pore-contained superstructures by a selective evolving process toward the fittest ion channel. The hybrid membranes presented here represent dynamic constitutional systems evolving over time to form the fittest ion channels from a library of molecular and supramolecular components, or selecting the fittest ion pairs from a mixture of salts demonstrating flexible adaptation.

Supramolecular self-organization in constitutional hybrid materials

We present in this paper a new strategy to transcribe the supramolecular dynamic self-organization of the G-quadruplex and ureidocrown ether ion channel-type columnar architectures in constitutional hybrids. In particular, the use of a “dynamic reversible hydrophobic interface” can render the emerging hybrid mesophases self-adaptive. The reversible hydrophobic interactions allow both supramolecular and inorganic silica components to mutually (synergistically) adapt their spatial constitution during simultaneous (collective) formation of micrometric self-organized hybrid domains. More generally, applying such consideration to materials, leads to the definition of constitutional hybrid materials, in which organic (supramolecular)/inorganic domains are reversibly connected. This might provide new insights into the features that control the design of functional materials.