Hydrophilic Flexible Ether Containing, Cross-Linked Anion-Exchange Membrane Quaternized with DABCO

Abstract

Anion-exchange membranes (AEM) with high ion content usually suffer from excessive water absorption and dilution effects that impair conductivity and mechanical properties. We herein report a novel ether containing a cross-linking strategy without adopting high ion-exchange capacity (IEC). The ether-containing cross-links and the quaternized structure are created simultaneously by introducing an ether-containing flexible hydrophilic spacer between two 1,4-diazabicyclo­[2,2,2,2]­octane or DABCO molecules; the resultant bi-DABCO structure was further employed to react with chloromethylated polysulfone. The long spacer with the ether moiety may benefit the hydroxide ion transport, and the cross-links will control the swelling and water absorption of the AEM. The two ether groups in the long spacer of the cross-links will also shield the DABCO cation from OH– attack due to an electron-donating effect. The prepared membranes exhibited an improved conductivity of 31 mS/cm (at 25 °C) at a comparatively low IEC (1.08 mmol/g) with a rational water absorption and low swelling ratio (95.0 and 27.1%, respectively); they also displayed an enhanced alkaline stability in 1 M NaOH aqueous solution at 80 °C for 150 h. The density functional theory study and physical characterization after the alkaline treatment further confirm the better chemical stability of the cross-linked membrane over its counterpart. Our work presents an effective strategy to balance AEM conductivity and robustness.

Cation–dipole interaction that creates ordered ion channels in an anion exchange membrane for fastOH−conduction

“…52,53 The To compare our membranes with recently reported AEMs, we summarize the AEMFCs peak power densities as a function of room temperature OH − conductivities for recently reported AEMs that based on similar aryl ether-containing polyaromatics backbone (Figure 4g and Table S2). 9,20,21,47,[54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] And our QA38PPO-P membrane show a competitive OH − conductivity and fuel cell performance among these AEMs. This highlights the advantages of developing AEMs containing well-defined cation-dipole interaction networks, which can form inter-connected ionic channels that facilitate ion transport.…”

Performance of Quaternized Polybenzimidazole-Cross-Linked Poly(vinylbenzyl chloride) Membranes in HT-PEMFCs

“…A potentially good amine for the application in IPMs is 1,4-diazabicyclo(2.2.2)­octane (DABCO) (see Figure ), which is, for example, known for its use in the research field of anion-exchange membranes. , In this work, its performance as a quaternizing agent for OPBI- c -PVBC cross-linked membrane systems for the application in HT-PEMFCs was investigated. Furthermore, the amines 1-azabicyclo(2.2.2)­octan-3-ol (quinuclidinol) and 1-azabicyclo(2.2.2)­octane (quinuclidine) (see Figure ) were chosen as structural relatives to DABCO.…”

Pendent Persubstituted Imidazolium and a Polyimidazolium Cross-Linked Polymer as Robust Alkaline Anion Exchange Membranes for Solid-State Zn–Air Batteries

“…Along with this, the high oxidative and mechanical stability of AEMs holds a critical role during the working in batteries. Numerous polar cationic groups have been investigated for their alkaline stability including guanidinium-, DABCO-, , pyrrolidinium-, , sulfonium-, and phosphonium-based , cations. However, exposure of these cations to a high pH and temperature leads to fast degradation in a relatively shorter time period.…”