Equilibrium partitioning of ions between a membrane and a contiguous external solution strongly influences transport properties of polymeric membranes used for water purification and energy generation applications. This study presents a theoretical framework to quantitatively predict ion sorption from aqueous electrolytes (e.g., NaCl, MgCl2) into charged (i.e., ion exchange) polymers. The model was compared with experimental NaCl, MgCl2, and CaCl2 sorption data in commercial cation and anion exchange membranes. Ion sorption in charged polymers was modeled using a thermodynamic approach based on Donnan theory coupled with Manning's counter-ion condensation theory to describe non-ideal behavior of ions in the membrane. Ion activity coefficients in solution were calculated using the Pitzer model. The resulting model, with no adjustable parameters, provides remarkably good agreement with experimental values of membrane mobile salt concentration. The generality of the model was further demonstrated using literature data for ion sorption of various electrolytes in charged polymers, including HCl sorption in Nafion.
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http://dx.doi.org/10.1039/c5cp06747b | DOI Listing |
Sci Rep
January 2025
School of Chemistry and Chemical Engineering, Heze University, Heze, 274015, People's Republic of China.
A novel adsorbent ZnAl-LDHs/SiO (ZA/SiO) was prepared by blending urea mixture of ZnSO and Al(SO) while using SiO as a support form. The adsorption properties of ZA/SiO for the removal of toxic metal ions (Cu(II) and Cr(VI)) from water were evaluated. By batch experiment method to investigate the ZA/SiO adsorption of Cu(II) and Cr(VI) solution treatment effect.
View Article and Find Full Text PDFTalanta
January 2025
National University of Uzbekistan Named After Mirzo Ulugbek, Tashkent, 100174, Uzbekistan.
Although significant progress has been made in the effective measurement of Zn(II), Аlizarin red S (ARS) was immobilized on polyethylene polyamine-modified polyacrylonitrile (PPF-1) via a new matrix. This approach allows the detection of low levels of Zn(II) ions in various water samples via preconcentrated atomic absorption spectrometry. The use of PPF-1 in a polymer matrix for zinc preconcentration presents several advantages over traditional sorbtion-spectroscopic methods, including reduced cost, high zinc recovery, increased sensitivity, and selectivity.
View Article and Find Full Text PDFChem Sci
December 2024
Instituto de Ciencia Molecular (ICMol), Universidad de Valencia c/Catedrático José Beltrán 2 Paterna 46980 Spain
We present the synthesis of a lanthanoid-organic framework (LOF) featuring a dynamic structure that exhibits tunable magnetic properties. The LOF undergoes breathing and gate-opening phenomena in response to changes in DMF content and N sorption, leading to the emergence of new crystal phases with distinct characteristics. Notably, the desolvated form of the LOF excels as a single-ion magnet, while the fully activated structure demonstrates impressive qubit properties, exhibiting Rabi oscillations up to 60 K.
View Article and Find Full Text PDFDalton Trans
January 2025
Department of Chemistry, Jadavpur University, Jadavpur, Kolkata-700 032, West Bengal, India.
This study presents the synthesis of a Cd(II) based hydrophobic three dimensional crystalline network material (CNM), [Cd(L)(LH)(bpe)], {L = {4,4'-(hexafluroisopropylidine)bis(benzoate)} and 1,2-di(4-pyridyl) ethylene (bpe)}, 1(Cd), by employing the slow-diffusion method. The three-dimensional structure of 1(Cd) was determined by single crystal X-ray diffraction and characterized by powder X-ray diffraction (PXRD), FT-IR spectroscopy and thermogravimetric analysis (TGA). Subsequently, post-synthetic modification of 1(Cd) with Cu(II) at room temperature led to the formation of isostructural 1(Cu) with partial substitution.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Physics and Astronomy and Thomas Young Centre, University College London, London WC1E 6BT, United Kingdom.
Atomic-scale understanding of important geochemical processes including sorption, dissolution, nucleation, and crystal growth is difficult to obtain from experimental measurements alone and would benefit from strong continuous progress in molecular simulation. To this end, we present a reactive neural network potential-based molecular dynamics approach to simulate the interaction of aqueous ions on mineral surfaces in contact with liquid water, taking Fe(II) on hematite(001) as a model system. We show that a single neural network potential predicts rate constants for water exchange for aqueous Fe(II) and for the exergonic chemisorption of aqueous Fe(II) on hematite(001) in good agreement with experimental observations.
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