Mechanoassisted Synthesis of Sulfonated Covalent Organic Frameworks with High Intrinsic Proton Conductivity

Abstract

It is challenging to introduce pendent sulfonic acid groups into modularly built crystalline porous frameworks for intrinsic proton conduction. Herein, we report the mechanoassisted synthesis of two sulfonated covalent organic frameworks (COFs) possessing one-dimensional nanoporous channels decorated with pendent sulfonic acid groups. These COFs exhibit high intrinsic proton conductivity as high as 3.96 × 10(-2) S cm(-1) with long-term stability at ambient temperature and 97% relative humidity (RH). In addition, they were blended with nonconductive polyvinylidene fluoride (PVDF) affording a series of mixed-matrix membranes (MMMs) with proton conductivity up to 1.58 × 10(-2) S cm(-1) and low activation energy of 0.21 eV suggesting the Grotthuss mechanism for proton conduction. Our study has demonstrated the high intrinsic proton conductivity of COFs shedding lights on their wide applications in proton exchange membranes.

Design Principles for Covalent Organic Frameworks in Energy Storage Applications

“…Continuous-flow methods [93] and mechanochemical solid-states yntheses [91,92,94] have recently been reported for severalt ypes of COFs. The use of any new materiali no ur expansive energy infrastructure first requires that it be available in large quantities.…”

“…[91] They did this by using TpBpy-Me; [92] am echanochemically synthesized bipyridine-containing imine COF loaded with phosphoric acid. [91] They did this by using TpBpy-Me; [92] am echanochemically synthesized bipyridine-containing imine COF loaded with phosphoric acid.…”

Covalent Organic Frameworks: Chemical Approaches to Designer Structures and Built‐In Functions

“…NUS‐9 (R=H) (=TpPa‐SO 3 H COF; Figure b) with monosulfonyl edges exhibits a proton conductivity of 1.24×10 −2 S cm −1 under 97 % RH at 25 °C . The conductivity is improved to 3.96×10 −2 S cm −1 for NUS‐10 (R=SO 3 H), which contains bisulfonyl units (Figure b).…”

Kovalente organische Gerüstverbindungen: chemische Ansätze für Designerstrukturen und integrierte Funktionen

“…NUS‐9 (R=H) (=TpPa‐SO 3 H‐COF; Abbildung b) mit Monosulfylrändern zeigt eine Protonenleitfähigkeit von 1.24×10 −2 S cm −1 bei 97 % RH und 25 °C . Die Leitfähigkeit ist für NUS‐10 (R=SO 3 H) (Abbildung b), das Bisulfonyleinheiten enthält, auf 3.96×10 −2 S cm −1 verbessert.…”

“…COF-TpDb-AOk ann Uran-Ionen aus Tr ink-, Brunnen-, Fluss-und sogar Meerwasser entfernen. Nach der Behandlung mit COF-TpDb-AOi st die Restkonzentration in Meerwasser von anfangs 1000 auf 0.1 ppb verringert, deutlich unter dem Standard fürT rinkwasser (30 ppb [249] Die Leitfähigkeit ist fürN US-10 (R = SO 3 H) (Abbildung 57 b), das Bisulfonyleinheiten enthält, auf 3.96 10 À2 Scm À1 verbessert. NUS-10 (R = SO 3 H) ist ohne wesentlichen Verlust an Leitfähigkeit über mehr als 15 Tage Betrieb bei 25 8 8Cu nd 97 % RH stabil.…”