Supramolecular Switching of Ion-Transport in Nanochannels

Abstract

Noncovalent approaches to achieve smart ion-transport regulation in artificial nanochannels have garnered significant interest in the recent years because of their advantages over conventional covalent routes. Herein, we demonstrate a simple and generic approach to control the surface charge in mesoporous silica nanochannels by employing π-electron-rich charged motifs (pyranine-based donors) to interact with the surface of mesoporous silica modified with π-electron-deficient motifs (viologen-based acceptors) through a range of noncovalent forces, namely, charge-transfer, electrostatic, and hydrophobic interactions. The extent of each of these interactions was independently controlled by molecular design and pH, while employing them in a synergistic or antagonistic fashion to modulate the binding affinity of the charged motifs. This enabled the precise control of the surface charge of the nanochannels to achieve multiple ion-transport states.

Preparation Of ZnO/Co3O4 Hollow Microsphere By Pollen‐biological Template And Its Application In Photocatalytic Degradation

“…[55][56][57] These free radicals have a strong oxidizing power and can oxidize and decompose organic matter until they are completely mineralized into CO 2 and H 2 O. [58,59] Under the irradiation of visible light, the conduction band (CB) and the valence band (VB) of Co 3 [60,61] Therefore, the recombination of photogenerated charges can be suppressed under the irradiation of visible light. The two semiconductor materials can generate more electron-hole pairs, which are effectively separated and rapid transfered to the active sites, resulting in its enhanced activity compared with the single ZnO or Co 3 O 4 species.…”

Biomimetic Nanochannels: From Fabrication Principles to Theoretical Insights

“…Apart from above efforts, Eswaramoorthy et al proposed supramolecular control of surface charge through varieties of noncovalent forces, namely, charge-transfer, electrostatic, and hydrophobic interactions, etc. [89] Supramolecular chargetransfer (C-T) based nanopores can be built for gating ionic transport with charge-reversal surfaces. In this case, pyranine was employed as the donor and viologen as the acceptor, hence the surface charge can be manipulated from positive to neutral or negative.…”

Rational ion transport management mediated through membrane structures

“…[27,64,65] Hydrophilic and hydrophobic nanochannels tend to transport polar and nonpolar matter, respectively. [66][67][68] Taking advantage of the specific recognition between the target ions and molecules with binding sites on the inner walls, selective transport of specific cations [69,70] and anions [71][72][73] can be achieved. The performance of ion selectivity can be quantitatively reflected by the water flux, interception, and ionic conductance of these membranes.…”