The Impact of Polyphosphates on the Colloidal Stability of Laponite Particles.
| Autor: | Katana B; MTA-SZTE Momentum Biocolloids Research Group, Department of Physical Chemistry and Materials Science, Interdisciplinary Centre of Excellence, University of Szeged, 6720 Szeged, Hungary., Baptista J; Group of Polymers and Nanostructures, Federal Technological University of Paraná - UTFPR, 85902-490 Toledo, Paraná, Brazil.; Chemical Engineering, University of São Paulo - USP, 05508-800 São Paulo, Brazil., Schneider R; Group of Polymers and Nanostructures, Federal Technological University of Paraná - UTFPR, 85902-490 Toledo, Paraná, Brazil., de Oliveira RJ; Physical Chemistry of Materials Group, State University of Paraíba - UEPB, 58429-500 Campina Grande, Paraíba, Brazil., Szilágyi I; MTA-SZTE Momentum Biocolloids Research Group, Department of Physical Chemistry and Materials Science, Interdisciplinary Centre of Excellence, University of Szeged, 6720 Szeged, Hungary. |
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| Jazyk: | angličtina |
| Zdroj: | The journal of physical chemistry. B [J Phys Chem B] 2024 Jul 18; Vol. 128 (28), pp. 6957-6965. Date of Electronic Publication: 2024 Jul 09. |
| DOI: | 10.1021/acs.jpcb.4c03193 |
| Abstrakt: | The effect of polyphosphate (polyP) adsorption on the colloidal properties of disc-shaped laponite (LRD) particles was examined in aqueous dispersions with a focus on elucidating the interparticle forces that govern the colloidal stability of the systems. The charge and aggregation rate data of bare LRD exhibited an ionic strength-dependent trend, confirming the presence of double-layer repulsion and van der Waals attraction as major surface interactions. The charge of LRD particles significantly increased in magnitude at elevated polyP concentrations as a result of polyP adsorption and subsequent overcharging of the positively charged sites on the edges of the LRD discs. A transition from stable to unstable LRD colloids was observed with increasing polyP doses indicating the formation of aggregates in the latter systems due to depletion forces and/or bridging interactions induced by dissolved or adsorbed polyP, respectively. The degree of phosphate polymerization influenced neither the charge nor the aggregation mechanism. The findings clearly confirm that polyP adsorption was the driving phenomenon to induce particle aggregation in contrast to other clay types, where phosphate derivatives act as dispersion stabilizing agents. This study provides valuable insights into the early stages of aggregation in colloidal systems involving LRD and polyPs, which have a crucial role in predicting further material properties that are important to designing LRD-polyP composites for applications such as potential phosphate sources in chemical fertilizers. |
| Databáze: | MEDLINE |
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