We show that aqueous sodium sulfate solutions exhibit an unrealistically large degree of ion pairing and clustering when modeled using nonpolarizable force fields, with clusters resembling precipitate readily forming in a 0.5 m solution at ambient conditions. This aggregation behavior was found to be persistent in nonpolarizable water for a range of parameters of the sulfate anion. In contrast, a polarizable potential performs satisfactorily, producing a well dissolved salt with a degree of association that is consistent with activity data for real solutions. Most of this improvement is due to polarization of water molecules in the vicinity of the divalent sulfate anion, which enhances its solvation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ct100465g | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Council for Geoscience, Private Bag X112, Pretoria, 0001, South Africa.
One-step high-pressure and high-temperature direct aqueous mineral carbonation of tailings derived from mining of Platinum Group Metals in South Africa requires a fundamental understanding of the reactivity of the most dominant mineral phases, i.e. pyroxene and plagioclase (66 wt.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Engineering Research Center of Oil and Gas Field Chemistry, Universities of Shaanxi Provence, Xi'an Shiyou University, Xi'an 710065, China.
In order to solve the problems of long dissolution and preparation time, cumbersome preparation, and easy moisture absorption and deterioration during storage or transportation, acrylamide (AM), acrylic acid (AA), sodium p-styrene sulfonate (SSS), and cetyl dimethylallyl ammonium chloride (DMAAC-16) were selected as raw materials, and the emulsion thickener P(AM/AA/SSS), which can be instantly dissolved in water and rapidly thickened, was prepared by the reversed-phase emulsion polymerization method. DMAAC-16, the influence of emulsifier dosage, oil-water ratio, monomer molar ratio, monomer dosage, aqueous pH, initiator dosage, reaction temperature, reaction time, and other factors on the experiment was explored by a single-factor experiment, and the optimal process was determined as follows: the oil-water volume ratio was 0.4, the emulsifier dosage was 7% of the oil phase mass, the initiator dosage was 0.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Department of Biology, College of Science, Hail University, P.O. Box 2440, Ha'il 2440, Saudi Arabia.
Quinoa is recognized for its nutritional and pharmacological properties. This study aims to investigate the impact of salt stress induced by varying concentrations of sodium chloride (NaCl) on the production of phenolic compounds and their biological activities in different quinoa accessions. Leaves from three quinoa accessions (Q4, Q24, and Q45) cultivated under increasing NaCl treatments were subjected to chemical analysis using ethanol and water extract.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
School of Life and Health Sciences, Hainan Province Key Laboratory of One Health, Collaborative Innovation Center of One Health, Hainan University, No. 58 Renmin Avenue, Haikou 570228, China.
Inflammatory bowel disease (IBD) is a persistent inflammatory condition affecting the gastrointestinal tract, distinguished by the impairment of the intestinal epithelial barrier, dysregulation of the gut microbiota, and abnormal immune responses. (L.) , traditionally used in Chinese herbal medicine for gastrointestinal issues such as bleeding and dysentery, has garnered attention for its potential therapeutic benefits.
View Article and Find Full Text PDFMolecules
January 2025
College of Chemistry & Pharmacy, Northwest A&F University, 22 Xiong Road, Yangling 712100, China.
The separation of large polar constituents presents a substantial challenge in natural product research when employing column chromatography techniques, as the process is both complex and time-consuming. In this study, an acetonitrile/tetrahydrofuran/di-(2-ethylhexyl) phosphoric acid/aqueous saturated sodium chloride solvent system was developed and utilized for the countercurrent chromatography of polar constituents from L. seeds.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!