Anion conductive poly(2,6-dimethyl phenylene oxide)s with clicked bulky quaternary phosphonium groups

Understanding the Effect of Triazole on Crosslinked PPO–SEBS-Based Anion Exchange Membranes for Water Electrolysis

For anion exchange membrane water electrolysis (AEMWE), two types of anion exchange membranes (AEMs) containing crosslinked poly(phenylene oxide) (PPO) and poly(styrene ethylene butylene styrene) (SEBS) were prepared with and without triazole. The impact of triazole was carefully examined. In this work, the PPO was crosslinked with the non-aryl ether-type SEBS to take advantage of its enhanced chemical stability and phase separation under alkaline conditions. Compared to their triazole-free counterpart, the crosslinked membranes made with triazole had better hydroxide-ion conductivity because of the increased phase separation, which was confirmed by X-ray diffraction (XRD) and atomic force microscopy (AFM). Moreover, they displayed improved mechanical and alkaline stability. Under water electrolysis (WE) conditions, a triazole-containing crosslinked PPO–SEBS membrane electrode assembly (MEA) was created using IrO2 as the anode and a Pt/C catalyst as the cathode. This MEA displayed a current density of 0.7 A/cm2 at 1.8 V, which was higher than that of the MEA created with the triazole-free counterpart. Our study indicated that the crosslinked PPO–SEBS membrane containing triazoles had improved chemo-physical and electrical capabilities for WE because of the strong hydrogen bonding between triazole and water/OH−.

Enhanced antifungal activity of novel cationic chitosan derivative bearing triphenylphosphonium salt via azide-alkyne click reaction

As one of the most promising biopolymers for a variety of potential applications, chitosan has attracted much attention because of its unique biological, chemical, and physical properties. The functionalization of chitosan has been adopted to synthesize novel chitosan derivatives with improved water-solubility and excellent biological activities. In this paper, chitosan was functionalized with a triphenylphosphonium group by means of the copper (I) catalyzed azide-alkyne "click" reaction and has been investigated as potential polymer for agricultural antifungal biomaterial. The influence of chemical modification on the structural characteristics and water-solubility of chitosan was investigated by FTIR spectroscopy, ¹H NMR spectroscopy, elemental analysis, and UV-vis spectrum. Furthermore, the antifungal property of target chitosan derivative against four plant threatening fungal pathogens was evaluated and in vitro investigation demonstrated that triphenylphosphonium salt incorporated chitosan backbone had excellent antifungal property compared with chitosan and intermediate chitosan derivative. Notably, target chitosan derivative displayed relatively strongest antifungal effect with over 80% inhibitory index against Botrytis cinerea at 1.0 mg/mL. The results of a detailed antifungal study indicated that cationic chitosan derivative bearing 1,2,3-triazole and triphenylphosphonium moieties provided a promising platform for preparation of novel cationic antifungal biomaterials in the field of agriculture.

Multiple Enhancement Effects of Crown Ether in Tröger's Base Polymers on the Performance of Anion Exchange Membranes

The development of anion exchange membranes (AEMs) is hindered by the trade-off of ionic conductivity, alkaline stability, and mechanical properties. Tröger's base polymers (Tb-polymers) are recognized as promising membrane materials to overcome these obstacles. Herein, the AEMs made from Tb-poly(crown ether)s (Tb-PCEs) show good comprehensive performance. The influence of crown ether on the conductivity and alkaline stability of AEMs has been investigated in detail. The formation of hydronium ion-crown ether complexes and an obvious microphase-separated structure formed by the existence of crown ether can enhance the conductivity of the AEMs. The maximum OH^- conductivity of 141.5 mS cm^-1 is achieved from the Tb-PCEs based AEM (Tb-PCE-1) at 80 °C in ultrapure water. The ion-dipole interaction of the Na⁺ with crown ether can protect the quaternary ammonium from the attack of OH^- to improve the alkaline stability of AEMs. After 675 h of alkaline treatment, the OH^- conductivity of Tb-PCE-1 decreases by only 6%. The Tb-PCE-1-based single cell shows a peak power density of 0.202 W cm^-2 at 80 °C. The prominent physicochemical properties are attributed to the well-developed microstructure of the Tb-PCEs, as revealed by TEM, AFM, and SAXS observations.

Crosslinked metallo-polyelectrolytes with enhanced flexibility and dimensional stability for anion-exchange membranes

We report a class of crosslinked metallo-polyelectrolytes as anion exchange membranes with exceptional mechanical flexibility, dimensional stability and ionic conductivity.