Colloidal Behavior of Aluminum Oxide Nanoparticles As Affected by pH and Natural Organic Matter

Ghosh, Swapankumar; Mashayekhi, Hamid; Pan, Bo; Bhowmik, Pradip K.; Xing, Baoshan

doi:10.1021/la802015f

Cited by 197 publications

(130 citation statements)

References 28 publications

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“…Steric hindrance effects may also contribute to the enhanced stability of humiccoated NPs. Conversely, Ghosh and co-workers [63] showed that at low pH, humic acid caused aggregation of Al 2 O 3 NPs. Here, the charge of the humic acid appeared sufficiently low to allow its aggregation because of hydrophobic interactions; thus, humic acid-coated particles also became susceptible to aggregation.…”

Section: Soil Propertiesmentioning

confidence: 97%

“…This sorption may influence particle properties in a number of ways. Humic substances are negatively charged at environmental pHs, and thus their sorption will make the overall particle-humic conglomerate negatively charged [63]. This may increase particle stability in solution, reducing aggregation and settling [48,61].…”

Section: Soil Propertiesmentioning

confidence: 99%

“…Aggregation tends to increase the importance of pore straining as a retention mechanism by producing a range of aggregate sizes that overlap to a greater extent with the size distribution of soil pores. The influence of pore straining in particle retention thus tends to depend on similar factors to those controlling aggregation, for example, pH and ionic strength [63]. Increases in particle size attributable to aggregation may also be associated with chemical conditions favoring sorption to the soil (e.g., pH, iso-electric point).…”

Section: Transport Of Metal-based Nps In Soilmentioning

confidence: 99%

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Metal‐based nanoparticles in soil: Fate, behavior, and effects on soil invertebrates

Tourinho

Gestel²,

Lofts

et al. 2012

Enviro Toxic and Chemistry

396

229

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Abstract-Metal-based nanoparticles (NPs) (e.g., silver, zinc oxide, titanium dioxide, iron oxide) are being widely used in the nanotechnology industry. Because of the release of particles from NP-containing products, it is likely that NPs will enter the soil compartment, especially through land application of sewage sludge derived from wastewater treatment. This review presents an overview of the literature dealing with the fate and effects of metal-based NPs in soil. In the environment, the characteristics of NPs (e.g., size, shape, surface charge) and soil (e.g., pH, ionic strength, organic matter, and clay content) will affect physical and chemical processes, resulting in NP dissolution, agglomeration, and aggregation. The behavior of NPs in soil will control their mobility and their bioavailability to soil organisms. Consequently, exposure characterization in ecotoxicological studies should obtain as much information as possible about dissolution, agglomeration, and aggregation processes. Comparing existing studies is a challenging task, because no standards exist for toxicity tests with NPs. In many cases, the reporting of associated characterization data is sparse, or missing, making it impossible to interpret and explain observed differences in results among studies. Environ. Toxicol. Chem.

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Section: Soil Propertiesmentioning

confidence: 97%

Section: Soil Propertiesmentioning

confidence: 99%

Section: Transport Of Metal-based Nps In Soilmentioning

confidence: 99%

See 1 more Smart Citation

Metal‐based nanoparticles in soil: Fate, behavior, and effects on soil invertebrates

Tourinho

Gestel²,

Lofts

et al. 2012

Enviro Toxic and Chemistry

396

229

View full text Add to dashboard Cite

show abstract

“…In asymmetric bridging the polymer first attaches to one of the surfaces, leading to a modification in polymer configuration and entropy, which enables it to attach to the other particle it may otherwise not have interacted with [142]. Although studies of asymmetric bridging in NPs-based systems are sparse, factors affecting morphology of polymers such as pH, ionic strength, and temperature [144][145][146] are expected to affect heteroaggregation occurring via polymer bridging. Heteroaggregation via bridging may also refer to a phenomenon where a NPs connects to at least two other NPs (both similar) in a sandwich-like manner [147].…”

Section: Bridgingmentioning

confidence: 99%

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Wang

Adeleye

Huang

et al. 2015

Advances in Colloid and Interface Science

169

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The application of nanoparticles has raised concern over the safety of these materials to human health and the ecosystem. After release into an aquatic environment, nanoparticles are likely to experience heteroaggregation with biocolloids, geocolloids, natural organic matter (NOM) and other types of nanoparticles. Heteroaggregation is of vital importance for determining the fate and transport of nanoparticles in aqueous phase and sediments. In this article, we review the typical cases of heteroaggregation between nanoparticles and biocolloids and/or geocolloids, mechanisms, modeling, and important indicators used to determine heteroaggregation in aqueous phase. The major mechanisms of heteroaggregation include electric force, bridging, hydrogen bonding, and chemical bonding. The modeling of heteroaggregation typically considers DLVO, X-DLVO, and fractal dimension. The major indicators for studying heteroaggregation of nanoparticles include surface charge measurements, size measurements, observation of morphology of particles and aggregates, and heteroaggregation rate determination. In the end, we summarize the research challenges and perspective for the heteroaggregation of nanoparticles, such as the determination of α hetero values and heteroaggregation rates; more accurate analytical methods instead of DLS for heteroaggregation measurements; sensitive analytical techniques to measure low concentrations of nanoparticles in heteroaggregation systems; appropriate characterization of NOM at the molecular level to understand the structures and fractionation of NOM; effects of different types, concentrations, and fractions of NOM on the heteroaggregation of nanoparticles; the quantitative adsorption and desorption of NOM onto the surface of nanoparticles and heteroaggregates; and a better understanding of the fundamental mechanisms and modeling of heteroaggregation in natural water which is a complex system containing NOM, nanoparticles, biocolloids and geocolloids.

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“…In natural aqueous media, large NP agglomerates will deposit faster than single particles due to their gravity, and will be blocked easily while transporting into a porous media (Chen and Elimelech, 2007;Ghosh et al, 2008;Petosa et al, 2010). NPs interact with natural organic matter (NOM) under various chemical solutions, which controls the agglomeration of NPs, as well as their attachment to environmental surfaces (Keller et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Effects of humic acid and bovine serum albumin on the agglomeration and sedimentation of oxide nanoparticles

Lin

Chen

et al. 2014

J. Zhejiang Univ. Sci. A

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Abstract:To better understand the nanoparticle (NP) transport in the environment, the agglomeration and sedimentation of Al 2 O 3 , SiO 2 , and TiO 2 NPs were evaluated after being treated with bovine serum albumin (BSA) and a commercial humic acid (HA). The morphology of NP agglomerates was examined through a transmission electron microscope (TEM), and the agglomeration kinetics was evaluated using established time-resolved dynamic light scattering techniques. BSA treatments decreased the hydrodynamic diameters (d H ) of the three NPs in both NaCl and CaCl 2 electrolytes due to their steric repulsive forces caused by the BSA globular architecture. The treatments using HA induced the smallest d H of NPs in NaCl electrolyte, but the largest d H of NPs was found in CaCl 2 electrolyte, because the HA bound to each other via calcium complexation and thereby enhanced the NP agglomeration. The zeta potentials of NPs were not the dominant factor to affect agglomeration. The NP sedimentation kinetics were studied through measuring the suspension optical absorbance. It was shown that the BSA treatments retarded the sedimentation in most situations; however, HA treatments accelerated the sedimentation greatly in CaCl 2 electrolyte, which was consistent with the measured changes in the d H values. The smallest d H of HA-treated NPs in NaCl electrolyte did not result in the lowest sedimentation rate, which indicated that the agglomeration size was not the only factor to affect the NP sedimentation.

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Colloidal Behavior of Aluminum Oxide Nanoparticles As Affected by pH and Natural Organic Matter

Cited by 197 publications

References 28 publications

Metal‐based nanoparticles in soil: Fate, behavior, and effects on soil invertebrates

Metal‐based nanoparticles in soil: Fate, behavior, and effects on soil invertebrates

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Effects of humic acid and bovine serum albumin on the agglomeration and sedimentation of oxide nanoparticles

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