Latest knowledge on the reactivity of charged nanoparticulate complexants toward aqueous metal ions is discussed in mechanistic detail. We present a rigorous generic description of electrostatic and chemical contributions to metal ion binding by nanoparticulate complexants, and their dependence on particle size, particle type (i.e., reactive sites distributed within the particle body or confined to the surface), ionic strength of the aqueous medium, and the nature of the metal ion. For the example case of soft environmental particles such as fulvic and humic acids, practical strategies are delineated for determining intraparticulate metal ion speciation, and for evaluating intrinsic chemical binding affinities and heterogeneity. The results are compared with those obtained by popular codes for equilibrium speciation modeling (namely NICA-Donnan and WHAM). Physicochemical analysis of the discrepancies generated by these codes reveals the a priori hypotheses adopted therein and the inappropriateness of some of their key parameters. The significance of the characteristic time scales governing the formation and dissociation rates of metal-nanoparticle complexes in defining the relaxation properties and the complete equilibration of the metal-nanoparticulate complex dispersion is described. The dynamic features of nanoparticulate complexes are also discussed in the context of predictions of the labilities and bioavailabilities of the metal species.
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http://dx.doi.org/10.1021/acs.est.9b00624 | DOI Listing |
Langmuir
January 2025
College of Chemistry and Chemical Engineering, Qingdao University, Qingdao 266071, China.
The recovery of valuable materials from spent lithium-ion batteries (LIBs) has experienced increasing demand in recent years. Current recycling technologies are typically energy-intensive and are often plagued by high operation costs, low processing efficiency, and environmental pollution concerns. In this study, an efficient and environmentally friendly dielectrophoresis (DEP)-based approach is proposed to separate the main components of "black mass" mixtures from LIBs, specifically lithium iron phosphate (LFP) and graphite, based on their polarizability differences.
View Article and Find Full Text PDFNative ion channels play key roles in biological systems, and engineered versions are widely used as chemogenetic tools and in sensing devices . Protein design has been harnessed to generate pore-containing transmembrane proteins, but the capability to design ion selectivity based on the interactions between ions and selectivity filter residues, a crucial feature of native ion channels , has been constrained by the lack of methods to place the metal-coordinating residues with atomic-level precision. Here we describe a bottom-up RFdiffusion-based approach to construct Ca channels from defined selectivity filter residue geometries, and use this approach to design symmetric oligomeric channels with Ca selectivity filters having different coordination numbers and different geometries at the entrance of a wide pore buttressed by multiple transmembrane helices.
View Article and Find Full Text PDFManganese (Mn)-sensing riboswitches protect bacteria from Mn toxicity by upregulating expression of Mn exporters. The Mn aptamers share key features but diverge in other important elements, including within the metal-binding core. Although X-ray crystal structures of isolated aptamers exist, these structural snapshots lack crucial details about how the aptamer communicates the presence or absence of ligand to the expression platform.
View Article and Find Full Text PDFRSC Adv
January 2025
Waste Recycling Technologies, Materials & Chemistry Unit, Flemish Institute for Technological Research, VITO N.V. Boeretang 200 B-2400 Mol Belgium
Antimony is a critical raw material in Europe wherein for 43% of its market share it is applied in the form of antimony trioxide as a fire retardant in plastics. Currently, antimony recycling from waste plastics does not take place and has been scarcely studied. In this work, a process was developed to extract antimony from a soft PVC material and recover it as SbClO.
View Article and Find Full Text PDFAll-solid-state Li-ion batteries (ASSBs) represent a promising leap forward in battery technology, rapidly advancing in development. Among the various solid electrolytes, argyrodite thiophosphates Li6PS5X (X = Cl, Br, I) stand out due to their high ionic conductivity, structural flexibility, and compatibility with a range of electrode materials, making them ideal candidates for efficient and scalable battery applications. However, despite significant performance advancements, the sustainability and recycling of ASSBs remain underexplored, posing a critical challenge for achieving efficient circular processes.
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