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Atomistic molecular dynamics simulations have been employed to study the self-ion (H and OH) distribution at the interface between long-chain C-OH alcohol (cetyl alcohol) monolayer and water. It is well known that the free air-water interface is acidic due to accumulation of the hydronium (HO) ions at the interface. In the present study, we have observed that contrary to the air-water interface, at the long-chain alcohol monolayer-water interface, it is the hydroxide (OH) ion, not the hydronium ion (HO) that gets accumulated. By calculating the potential of mean forces, it is confirmed that there is extra stabilization for the OH ions at the interface relative to the bulk, but no such stabilization is observed for the HO ions. By analyzing the interaction of the self-ions with other constituents in the medium, it is clearly shown that the favorable interaction of the OH ions with the alcoholic -OH groups stabilizes this ion at the interface. By calculating coordination numbers of the self-ions it is observed that around 50% water neighbors are substituted by alcoholic -OH in case of the hydroxide ion at the interface, whereas in the case of hydronium ions, only 15% water neighbors are substituted by the alcoholic -OH. The most interesting observation about the local structure and H-bonding pattern is that the hydroxide ion acts solely as the H-bond acceptor, but the hydronium ion acts only as the H-bond donor.
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http://dx.doi.org/10.1021/acs.jpcb.2c05719 | DOI Listing |
J Org Chem
September 2025
Department of Chemistry, Indian Institute of Technology Guwahati, North Guwahati 781039, India.
The synthesis of α-ketoamides through oxidative ring opening of 1-acetylindoline-3-one under electrochemical conditions is reported. In an undivided cell, the reaction proceeds via the formation of an iminium ion intermediate, nucleophilic attack by a hydroxide ion, and subsequent ring opening through pre-existing C-N bond cleavage. The reaction in the presence of HO confirms that the amidic oxygen originated from the moisture present in the medium.
View Article and Find Full Text PDFResearch (Wash D C)
August 2025
Materials Science, Energy and Nanoengineering (MSN) Department, University Mohammed VI Polytechnic, Ben Guerir, Morocco.
Water electrolysis is a key industrial process for producing green hydrogen. To avoid the use of noble metals and fluorinated polymer membranes, liquid water electrolysis is often carried out in alkaline conditions. It is common to distinguish between 3 processes: alkaline electrolysis at high electrolyte concentrations (≥7 M) with porous membranes, alkaline electrolysis at high electrolyte concentrations (≥7 M) with ion-solvating membranes, and alkaline electrolysis at moderate electrolyte concentrations (<2 M) with anion-exchange membranes.
View Article and Find Full Text PDFBiomolecules
July 2025
Key Laboratory of Chemo/Biosensing and Detection of Xuchang, Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Henan Joint International Research Laboratory of Nanomaterials for Energy and Catalysis, College of Chemical and Materials Engineering, Xuchang Uni
In the context of critical challenges in curcumin-modified polyurethane synthesis-including limited curcumin bioavailability and suboptimal biodegradability/biocompatibility-a novel polyurethane material (Cur-PU) with good mechanical, shape memory, pH-responsive, and biocompatibility was synthesized via a one-pot, two-step synthetic protocol in which HO-PCL-OH served as the soft segment and curcumin was employed as the chain extender. The experimental results demonstrate that with the increase in Cur units, the crystallinity of the Cur-PU material decreases from 32.6% to 5.
View Article and Find Full Text PDFMembranes (Basel)
July 2025
Department of Chemical and Biomolecular Engineering, Universidad de Cantabria, A. Los Castros s/n, 39005 Santander, Spain.
The demand for anion exchange membranes (AEMs) is growing due to their applications in water electrolysis, CO reduction conversion and fuel cells, as well as water treatment, driven by the increasing energy demand and the need for a sustainable future. However, current AEMs still face challenges, such as insufficient permeability and stability in strongly acidic or alkaline media, which limit their durability and the sustainability of membrane fabrication. In this study, polyvinyl alcohol (PVA) and chitosan (CS) biopolymers are selected for membrane preparation.
View Article and Find Full Text PDFBioresour Technol
August 2025
Qingdao New Energy Shandong Laboratory, Qingdao Key Laboratory of Functional Membrane Material and Membrane Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China.
The recovery of volatile fatty acids (VFAs) from waste-activated sludge (WAS) is crucial for sustainable bio-based systems; however, low substrate degradability limits this process. This study combines heat-alkali pretreatment, NaSiO buffering for pH stabilization, and electrodialysis with bipolar membranes (EDBM) to enhance VFAs production and alkali recovery. Semi-continuous fermentation with ultrafiltration pretreatment achieved a maximum VFAs yield of 8.
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