Dynamics and Heterogeneity of Pb(II) Binding by SiO<sub>2</sub> Nanoparticles in an Aqueous Dispersion

Goveia, Danielle; Pinheiro, José Paulo; Milkova, Viktoria; Rosa, André Henrique; Leeuwen, Herman P. van

doi:10.1021/la2008182

Cited by 20 publications

(22 citation statements)

References 36 publications

(59 reference statements)

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“…These results are basically similar to the correction coefficient for the overall association and dissociation rate constants k a and k d as proposed by Pinheiro et al [23] and experimentally verified using metal complexes with silica NPs and surface-functionalized latex NPs [35,36]. As is clear now from the present analysis, the derived "lability" is actually an expression of the local chemodynamics of the particle in the surrounding medium.…”

Section: The Hard Np Case Of Surface Complexationsupporting

confidence: 90%

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Leeuwen

Town

2016

J Solid State Electrochem

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Lability concepts are elaborated for metal complexes with soft (3D) and hard (2D) aqueous nanoparticles. In the presence of a non-equilibrium sensor, e.g. a voltammetric electrode, the notion of lability for nanoparticulate metal complexes, M-NP, reflects the ability of the M-NP to maintain equilibrium with the reduced concentration of the electroactive free M 2+ in its diffusion layer. Since the metal ion binding sites are confined to the NP body, the conventional reaction layer in the form of a layer adjacent to the electrode surface is immaterial. Instead an intraparticulate reaction zone may develop at the particle/ medium interface. Thus the chemodynamic features of M-NP complexes should be fundamentally different from those of molecular systems in which the reaction layer is a property of the homogeneous solution (μ = (D M /k a ′ ) 1/2 ). For molecular complexes, the characteristic timescale of the electrochemical technique is crucial in the lability towards the electrode surface. In contrast, for nanoparticulate complexes it is the dynamics of the exchange of the electroactive metal ion with the surrounding medium that governs the effective lability towards the electrode surface.

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Section: The Hard Np Case Of Surface Complexationsupporting

confidence: 90%

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Leeuwen

Town

2016

J Solid State Electrochem

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“…Triclosan (purity .97 %, diffusion coefficient in water 6.1 Â 10 À10 m 2 s À1 at 25 8C [17] ), Ludox LS silica nanoparticles (mean radius of 7.5 nm as previously measured, [9,18] diffusion coefficient of 2.7 Â 10 À11 m 2 s…”

Section: Experimental Materialsmentioning

confidence: 70%

Solid phase microextraction speciation analysis of triclosan in aqueous media containing sorbing nanoparticles

Zielińska¹

2014

Environ. Chem.

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Environmental context. Speciation analysis of organic compounds in aquatic media is often performed using solid phase microextraction with the assumption that only the free organic form is accumulated. We show that in the presence of silica nanoparticles, this interpretation is confounded by partitioning of nanoparticulate-bound compounds between water and the solid phase, as well as their aggregation at solid-bulk medium interfaces. Equilibrium measurement of the target analyte is feasible if the solid phase is protected by a suitable membrane.Abstract. Solid phase microextraction (SPME) is applied in the speciation analysis of the hydrophobic compound triclosan in an aqueous medium containing sorbing SiO 2 nanoparticles (NPs). It is found that these NPs, as well as their complexes with triclosan, partition between the bulk medium and the solid phase poly(dimethylsiloxane) (PDMS). Furthermore, they appear to aggregate at the PDMS-water interface. The total triclosan concentration in the solid phase thus includes both the free and the NP-bound forms. Proper computation of the analyte concentration in the sample medium requires (i) consideration of the speciation of triclosan inside the solid phase and (ii) elimination of the effects of aggregation of NP complexes at the solid phase-bulk medium interface. Possible solutions include application of a protective membrane with pore size smaller than the NP diameter. This allows measurement of the free triclosan concentration, albeit at the cost of longer accumulation times and loss of kinetic information on the triclosan-NP complex.Additional keyword: SPME.

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“…Three suspensions were chosen for analysis: LUDOX LS30, LUDOX TM40 and LUDOX TM50. These nanoparticles used in these experiments were characterized in earlier studies (Table 1) 9 . Were added to the solutions 800 μL of LS30, 1070 μL of TM40 and 1330 μL of TM50 all in the proportion in moles of 1: 1.…”

Section: Evaluation Of Metal-binder Interactionsmentioning

confidence: 99%

“…Thus, it becomes even more important to know the dynamic nature of the complexes 9,10 . Our focus will be to understand the impact of silica nanoparticles on the matrix, that is, how they interfere in the speciation of iron and manganese metal ions in environmental systems, originally bound in organic matter.…”

Section: Introductionmentioning

confidence: 99%

Influence of the Diameter of Nanoparticles in Complexes Metal-Aquatic Humic Substances

et al. 2018

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Nanoparticles are emerging as the object of research in all fields of chemistry, their special properties are matter for concern, because a considerable portion of these materials are eliminated in the environment. A key point of the discussion is how nanoparticles will interact with other components in natural waters. In this project, the main objective will be to study the interactions of nanoparticles with metallic ions in the presence of humic substances in environmental systems. It is intended to differentiate free and labile metal ions using nanoparticles and organic matter in the form of aquatic substances (extracted from samples collected on the coast of São Paulo). It is intended to simulate the environmental systems and to verify the competition between the complexants. The differentiation of the free and complexed ions will be done using an ultrafiltration system equipped with polyethersulfone membrane (1KDa) and determination of the metals by atomic absorption spectrometry with flame atomization and graphite furnace.

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Dynamics and Heterogeneity of Pb(II) Binding by SiO₂ Nanoparticles in an Aqueous Dispersion

Cited by 20 publications

References 36 publications

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Solid phase microextraction speciation analysis of triclosan in aqueous media containing sorbing nanoparticles

Influence of the Diameter of Nanoparticles in Complexes Metal-Aquatic Humic Substances

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Dynamics and Heterogeneity of Pb(II) Binding by SiO2 Nanoparticles in an Aqueous Dispersion

Cited by 20 publications

References 36 publications

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Lability of nanoparticulate metal complexes in electrochemical speciation analysis

Solid phase microextraction speciation analysis of triclosan in aqueous media containing sorbing nanoparticles

Influence of the Diameter of Nanoparticles in Complexes Metal-Aquatic Humic Substances

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Dynamics and Heterogeneity of Pb(II) Binding by SiO₂ Nanoparticles in an Aqueous Dispersion