A systematic evaluation of agglomeration of Ag and TiO2 nanoparticles under freshwater relevant conditions.

A systematic evaluation of agglomeration of Ag and TiO2 nanoparticles under freshwater relevant conditions.

Environmental pollution (Barking, Essex : 1987) (2014-07-08)

Emel Topuz, Laura Sigg, Ilhan Talinli

RESUMEN

This study aims to investigate effects of freshwater components in order to predict agglomeration behavior of silver nanoparticles coated with citrate (AgNP-Cit), polyvinylpyrrolidone (AgNP-PVP), and of TiO2 nanoparticles. Agglomeration studies were conducted in various media based on combinations of ions, natural organic matter (humic, fulvic acid) and surfactants (sodium dodecyl sulfate, alkyl ethoxylate), at a constant ionic strength of 10 mM over time for up to 1 week. Agglomeration level of AgNP-Cit and TiO2 was mostly dependent on the concentration of Ca(2+) in media, and their size strongly increased to micrometer scale over 1 week. However, AgNP-Cit and TiO2 were stabilized to particle size around 500 nm in the presence of NOM, surfactants and carbonate over 1 week. AgNP-PVP maintained their original size in all media except in the presence of Mg(2+) ions which led to significant agglomeration. Behavior of these engineered nanoparticles was similar in a natural freshwater medium.

MATERIALES

Referencia del producto

Marca

Descripción del producto

27109

Sigma-Aldrich

Ácido cítrico, meets analytical specification of Ph. Eur., BP, USP, E330, anhydrous, 99.5-100.5% (based on anhydrous substance)

PVP360

Sigma-Aldrich

Polyvinylpyrrolidone, mol wt (number average molecular weight Mn 360kDa)

718467

Sigma-Aldrich

Óxido de titanio (IV), nanopowder, 21 nm primary particle size (TEM), ≥99.5% trace metals basis

437190

Sigma-Aldrich

Polyvinylpyrrolidone, average M_w ~1,300,000 by LS

PVP40

Sigma-Aldrich

Polyvinylpyrrolidone, average mol wt 40,000

856568

Sigma-Aldrich

Polyvinylpyrrolidone, powder, average M_w ~55,000

14027

Sigma-Aldrich

Óxido de titanio (IV), puriss., meets analytical specification of Ph. Eur., BP, USP, 99-100.5%

232033

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Titanium(IV) oxide, anatase, powder, 99.8% trace metals basis

14021

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Óxido de titanio (IV), ReagentPlus^®, ≥99%

251275

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Ácido cítrico, ACS reagent, ≥99.5%

234257

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Polyvinylpyrrolidone, powder, average M_w ~29,000

224227

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Titanium(IV) oxide, rutile, powder, <5 μm, ≥99.9% trace metals basis

P0930

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Polyvinylpyrrolidone, powder, BioXtra, suitable for mouse embryo cell culture

W230618

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Ácido cítrico, ≥99.5%, FCC, FG

248576

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Titanium(IV) oxide, anatase, powder, −325 mesh, ≥99% trace metals basis

C2404

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Ácido cítrico, anhydrous, suitable for cell culture, suitable for plant cell culture

1134368

USP

Ácido cítrico, United States Pharmacopeia (USP) Reference Standard

634662

Sigma-Aldrich

Titanium(IV) oxide, mixture of rutile and anatase, nanopowder, <100 nm particle size (BET), 99.5% trace metals basis

27487

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Ácido cítrico, BioUltra, anhydrous, ≥99.5% (T)

C0759

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Ácido cítrico, 99%

348791

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Titanium, foil, thickness 0.127 mm, 99.7% trace metals basis

81420

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Polyvinylpyrrolidone, K 30

739421

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Silver nanowires, diam. × L 50 nm × 6 μm, 0.5% (isopropyl alcohol suspension)

267503

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Titanium, foil, thickness 0.25 mm, 99.7% trace metals basis

700347

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Titanium(IV) oxide, mixture of rutile and anatase, nanoparticles, <150 nm particle size (volume distribution, DLS), dispersion, 40 wt. % in H₂O, 99.5% trace metals basis

PVP10

Sigma-Aldrich

Polyvinylpyrrolidone, average mol wt 10,000

02286

Sigma-Aldrich

Kollidon^® 25

327026

Sigma-Aldrich

Silver, wire, diam. 0.5 mm, 99.9% trace metals basis

81430

Sigma-Aldrich

Polyvinylpyrrolidone solution, K 60, 45% in H₂O

81440

Sigma-Aldrich

Polyvinylpyrrolidone, K 90