This work elucidates the potential impact of intramolecular H-bonds within the pore walls of covalent organic frameworks (COFs) on proton conductivity. Employing DaTta and TaTta as representative hosts, it was observed that their innate proton conductivities (σ) are both unsatisfactory and σ(DaTta)<σ(TaTta). Intriguingly, the performance of both imidazole-loaded products, Im@DaTta and Im@TaTta is greatly improved, and the σ of Im@DaTta (0.91×10 S cm ) even surpasses that of Im@TaTta (3.73×10 S cm ) under 100 °C and 98 % relative humidity. The structural analysis, gas adsorption tests, and activation energy calculations forecast the influence of imidazole on the H-bonded system within the framework, leading to observed changes in proton conductivity. It is hypothesized that intramolecular H-bonds within the COF framework impede efficient proton transmission. Nevertheless, the inclusion of an imidazole group disrupts these intramolecular bonds, leading to the formation of an abundance of intermolecular H-bonds within the pore channels, thus contributing to a dramatic increase in proton conductivity. The related calculation of Density Functional Theory (DFT) provides further evidence for this inference.
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http://dx.doi.org/10.1002/chem.202302146 | DOI Listing |
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January 2025
National Energy Metal Resources and New Materials Key Laboratory, Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy, School of Metallurgy and Environment, Central South University, Changsha, 410083, P. R. China.
Electrochemical CO reduction (CORR) in membrane electrode assembly (MEA) represents a viable strategy for converting CO into value-added multi-carbon (C) compounds. Therefore, the microstructure of the catalyst layer (CL) affects local gas transport, charge conduction, and proton supply at three-phase interfaces, which is significantly determined by the solvent environment. However, the microenvironment of the CLs and the mechanism of the solvent effect on C selectivity remains elusive.
View Article and Find Full Text PDFACS EST Air
January 2025
Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States.
Wildfires at the wildland-urban interface (WUI) have been increasing in frequency over recent decades due to increased human development and shifting climatic patterns. The work presented here focuses on the impacts of a WUI fire on indoor air using field measurements of volatile organic compounds (VOCs) by Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS). We found a slow decrease in VOC mixing ratios over the course of roughly 5 weeks starting 10 days after the fire, and those levels decreased to ∼20% of the initial indoor value on average.
View Article and Find Full Text PDFSurg Open Sci
January 2025
Klinikum Friedrichshafen GmbH, Department of Visceral Surgery, Röntgenstraße 2, 88048 Friedrichshafen, Germany.
Background: This study reports outcomes of the RefluxStop procedure treating gastroesophageal reflux disease (GERD) in clinical practice at a high-volume regional hospital in Germany.
Methods: A retrospective analysis was conducted on 79 patients with chronic GERD that underwent the RefluxStop procedure, comprising high mediastinal dissection, loose cruroplasty, esophagogastroplication between vagal trunks, and fundus invagination of the RefluxStop implant. The primary outcome was GERD Health-Related Quality-of-Life (GERD-HRQL) score and improvement from baseline.
Front Antibiot
May 2024
Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Ranchi, India.
Introduction: In response to continued public health emergency of antimicrobial resistance (AMR), a significant key strategy is the discovery of novel mycobacterial efflux-pump inhibitors (EPIs) as potential adjuvants in combination drug therapy. Interest in identifying new chemotypes which could potentially synergize with the existing antibiotics and can be deployed as part of a combination therapy. This strategy could delay the emergence of resistance to existing antibiotics and increase their efficacy against resistant strains of mycobacterial species.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Proton-electron mixed conductors (PEMCs) are an essential component for potential applications in hydrogen separation and energy conversion devices. However, the exploration of PEMCs with excellent mixed conduction, which is quantified by the ambipolar conductivity, σ = σσ/(σ + σ) (σ: electronic conductivity; σ: proton conductivity), is still a great challenge, largely due to the lack of structural characterization of both conducting mechanisms. In this study, we prepared a molecule-based proton-electron mixed-conducting cation radical salt, (ET)[Pt(pop)(Hpop)]·PhCN (ET: bis(ethylenedithio)tetrathiafulvalene, pop: PHO), by electrocrystallization.
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