Theories for the effective polarizability of a small particle in a medium are presented using different levels of approximation: we consider the virtual cavity, real cavity, and the hard-sphere models as well as a continuous interpolation of the latter two. We present the respective hard-sphere and cavity radii as obtained from density-functional simulations as well as the resulting effective polarizabilities at discrete Matsubara frequencies. This enables us to account for macroscopic media in van der Waals interactions between molecules in water and their Casimir-Polder interaction with an interface.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jpca.7b10159 | DOI Listing |
Sci Rep
January 2025
Department of Physics, Khalifa University, Abu Dhabi, United Arab Emirates.
The current research aims to determine the impact of orange peel dye (OPD), an eco-friendly addition, on the optical properties of biodegradable polymers. This study investigates the enhancement of optical properties in solid electrolytes based on chitosan (CS) and glycerol, with varying OPD concentrations. UV-Vis-NIR spectroscopy revealed significantly enhanced UV-visible light absorption in the 200-500 nm region and effective UV light blocking.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemistry "Ugo Schiff" and CSGI, University of Florence, 50019 Sesto Fiorentino, Italy.
Specific ion effects are widespread and have been studied for over a century, yet they remain poorly understood. Terms like "kosmotropes" and "chaotropes" are convenient rules of thumb but the frequent reversal of the Hofmeister series implies their limitations. Polarizability is often used to classify ions, with kosmotropes considered low in polarizability and chaotropes high.
View Article and Find Full Text PDFSci Rep
January 2025
DIMES Department, University of Calabria, Rende, 87036, Italy.
Despite their widespread adoption, particle-scale simulation methods, such as the Discrete Element Method (DEM), for electrically charged particles in several natural processes and industrial transformations do not include realistic polarization effects. At close distances, these can dominate the particle motion and are impossible to predict by the commonly adopted Coulomb point-charge approximation. Sophisticated mathematical tools can account for uneven charge distributions, predicting an attractive force between a charged particle and a neutral particle or possible attraction between two like-charged particles.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States.
Conventional methods for extracting rare earth metals (REMs) from mined mineral ores are inefficient, expensive, and environmentally damaging. Recent discovery of lanmodulin (LanM), a protein that coordinates REMs with high-affinity and selectivity over competing ions, provides inspiration for new REM refinement methods. Here, we used quantum mechanical (QM) methods to investigate trivalent lanthanide cation (Ln) interactions with coordination systems representing bulk solvent water and protein binding sites.
View Article and Find Full Text PDFPhotochem Photobiol Sci
January 2025
CQC-IMS, Department of Chemistry, University of Coimbra, 3004-535, Coimbra, Portugal.
Solvatochromism exhibited by azobenzene-4-sulfonyl chloride (here abbreviated as Azo-SCl) has been investigated in a series of non-polar, polar-aprotic and polar-protic solvents. The UV-vis spectra of Azo-SCl exhibit two long-wavelength bands, observed at 321-330 nm (band-I) and 435-461 nm (band-II), which are ascribed to the π*-π (S ← S) and π*-n (S ← S) transitions, respectively. The shorter wavelength band indicates a reversal in solvatochromism, from negative to positive solvatochromism, for a solvent with a dielectric constant of 32.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!