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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 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 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.
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http://dx.doi.org/10.1021/acsami.0c05411 | DOI Listing |
J Phys Chem A
September 2025
Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
The gas-phase structures of dibenzo-24-crown-8 (DB24C8) and dinaphtho-24-crown-8 (DN24C8) complexes with divalent metal ions (Mg, Ca, Sr, Ba, Fe, Ni, and Zn) were investigated by cryogenic ion mobility-mass spectrometry (IM-MS) in combination with density functional theory calculations. Several complexes, particularly those of DN24C8, exhibited multiple coexisting conformers. DFT-optimized structures were classified based on the relative orientation of the two aromatic rings in the crown ether.
View Article and Find Full Text PDFChempluschem
September 2025
Faculty of Chemistry, University of Warsaw, Pasteura 1, Warsaw, PL 02-093, Poland.
The design, synthesis, and characterization of a series of supramolecular receptors based on electron-deficient aromatic systems capable of engaging in anion-π interactions are reported. Receptors 1 and 3 combine an electron-poor aromatic scaffold with a cation-binding crown ether unit. Binding studies monitored by H NMR titrations in acetonitrile revealed that these receptors exhibit enhanced affinity for bromide anions in the presence of sodium cations, indicating cooperative ion-pair recognition.
View Article and Find Full Text PDFBiochemistry
September 2025
Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.
The recent discovery that the model multidrug efflux pump from , EmrE, can perform multiple types of transport suggests that this may be a compelling target for therapeutic intervention. Initial studies have identified several small-molecule substrates capable of inducing transporter-dependent susceptibility rather than the well-known antibiotic resistance phenotype. However, many questions regarding the underlying mechanism and regulation of this transporter still remain.
View Article and Find Full Text PDFCarbohydr Res
November 2025
Centre for Fundamental and Frontier Sciences in Nanostructure Self-Assembly, Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
Six new macrocycles incorporating glycolipids containing one triazole ring in their structures were synthesized via intramolecular macrocyclic closure. The synthesis strategy is based on the different reactivities of primary and secondary hydroxyl groups on the monosaccharides. The protecting of hydroxyls on 4,6-positions by benzylidene, followed by benzylation of 2,3-positions and removal of the benzylidene, selectively left over the free secondary and primary hydroxyl on 4- and 6-carbons, respectively.
View Article and Find Full Text PDFPolymers (Basel)
August 2025
Department of Dental Medicine and Nursing, Faculty of Medicine, Lucian Blaga University of Sibiu, 550169 Sibiu, Romania.
Polyethersulfone (PES) is one of the most used synthetic polymers for the production of hemodialysis membranes, due to its appropriate features, such as biocompatibility, high permeability for low-molecular-weight proteins, high endotoxin retention ability, and resistance to sterilization processes. However, there is room for improvement regarding their anticoagulant properties when coming into contact with blood. In the present study, commercial PES membranes were plasma-treated and then chemically modified with crown ether, an organic compound that could interfere with the coagulation cascade by complexating Ca in the blood.
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