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Colloidal Interactions of Microplastic Particles with Anionic Clays in Electrolyte Solutions

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Journal Langmuir
Specialty Chemistry
Date 2023 Aug 30
PMID 37647144
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Abstract

Homoaggregation of polystyrene microplastics (MPs) and heteroaggregation of MPs with anionic clay minerals, namely, layered double hydroxide (LDH), in different salt (NaCl, CaCl, and NaSO) solutions were systematically investigated using light scattering techniques. The salt type and ionic strength had significant effects on the stability of both MPs and LDH particles individually and the results could be explained by DLVO theory and the Schulze-Hardy rule. However, once stable colloidal dispersions of the individual particles were mixed, heteroaggregation occurred between the oppositely charged MPs and LDH, which was also confirmed by transmission electron microscopy and X-ray scattering. Adsorption of the LDH particles resulted in neutralization and reversal of MPs surface charge at appropriate LDH doses. Once LDH adsorption neutralized the negative charges of the MP spheres, rapid aggregation was observed in the dispersions, whereas stable samples formed at high and low LDH concentrations. The governing interparticle interactions included repulsive electrical double-layer forces, as well as van der Waals and patch-charge attractions, the strength of which depended on the mass ratio of the interacting particles and the composition of the aqueous solvent. Our results shed light on the colloidal behavior of MPs in a complex aquatic environment and, in the long term, are also useful for developing LDH-based approaches for water remediation to remove contamination with MP particles.

References
1.
Holmes L, Turner A, Thompson R . Adsorption of trace metals to plastic resin pellets in the marine environment. Environ Pollut. 2011; 160(1):42-8. DOI: 10.1016/j.envpol.2011.08.052. View

2.
Alsharif N, Bere K, Saringer S, Samu G, Takacs D, Hornok V . Design of hybrid biocatalysts by controlled heteroaggregation of manganese oxide and sulfate latex particles to combat reactive oxygen species. J Mater Chem B. 2021; 9(24):4929-4940. DOI: 10.1039/d1tb00505g. View

3.
Tiwari E, Singh N, Khandelwal N, Abdolahpur Monikh F, Darbha G . Application of Zn/Al layered double hydroxides for the removal of nano-scale plastic debris from aqueous systems. J Hazard Mater. 2020; 397:122769. DOI: 10.1016/j.jhazmat.2020.122769. View

4.
Wu J, Liu J, Wu P, Sun L, Chen M, Shang Z . The heteroaggregation and deposition behavior of nanoplastics on AlO in aquatic environments. J Hazard Mater. 2022; 435:128964. DOI: 10.1016/j.jhazmat.2022.128964. View

5.
Oncsik T, Trefalt G, Borkovec M, Szilagyi I . Specific ion effects on particle aggregation induced by monovalent salts within the Hofmeister series. Langmuir. 2015; 31(13):3799-807. DOI: 10.1021/acs.langmuir.5b00225. View