https://scholars.lib.ntu.edu.tw/handle/123456789/611473
標題: | Aggregation Behavior of Inorganic 2D Nanomaterials beyond Graphene: Insights from Molecular Modeling and Modified DLVO Theory | 作者: | Mohona T.M. Gupta A. Masud A. Chien S.-C. Lin L.-C. Nalam P.C. Aich N. LI-CHIANG LIN |
關鍵字: | Biological materials;Electrolytes;Ionic strength;Layered semiconductors;Molecular modeling;Molybdenum compounds;Nanosheets;Nanostructured materials;Sodium chloride;Tungsten compounds;Van der Waals forces;Critical coagulation concentration (ccc);Electrical double layers;Electrolyte concentration;Electrosteric repulsion;Molecular level interactions;Natural aquatic environments;Suwanee river natural organic matters;Van der Waals attraction;Boron nitride;calcium chloride;electrolyte;graphene;nanomaterial;nanosheet;natural organic matter;graphite;aggregation;carbon;coagulation;concentration (composition);electrical method;molecular analysis;numerical model;organic matter;theoretical study;aquatic environment;Article;dispersion;ecosystem;hydrodynamics;ionic strength;limited mobility;macromolecule;molecular model;photon correlation spectroscopy;static electricity;kinetics;Ecosystem;Graphite;Kinetics;Nanostructures | 公開日期: | 2019 | 卷: | 53 | 期: | 8 | 起(迄)頁: | 4161-4172 | 來源出版物: | Environmental Science and Technology | 摘要: | We report the comparative aggregation behavior of three emerging inorganic 2D nanomaterials (NMs): MoS2, WS2, and h-BN in aquatic media. Their aqueous dispersions were subjected to aggregation under varying concentrations of monovalent (NaCl) and divalent (CaCl2) electrolytes. Moreover, Suwanee River Natural Organic Matter (SRNOM) has been used to analyze the effect of natural macromolecules on 2D NM aggregation. An increase in electrolyte concentration resulted in electrical double-layer compression of the negatively charged 2D NMs, thus displaying classical Derjaguin-Landau-Verwey-Overbeek (DLVO)-type interaction. The critical coagulation concentrations (CCC) have been estimated as 37, 60, and 19 mM NaCl and 3, 7.2, and 1.3 mM CaCl2 for MoS2, WS2, and h-BN, respectively. Theoretical predictions of CCC by modified DLVO theory have been found comparable to the experimental values when dimensionality of the materials is taken into account and a molecular modeling approach was used for calculating molecular level interaction energies between individual 2D NM nanosheets. Electrostatic repulsion has been found to govern colloidal stability of MoS2 and WS2 while the van der Waals attraction has been found to govern that of h-BN. SRNOM stabilizes the 2D NMs significantly possibly by electrosteric repulsion. The presence of SRNOM completely stabilized MoS2 and WS2 at both low and high ionic strengths. While h-BN still showed appreciable aggregation in the presence of SRNOM, the aggregation rates were decreased by 2.6- and 3.7-fold at low and high ionic strengths, respectively. Overall, h-BN nanosheets will have higher aggregation potential and thus limited mobility in the natural aquatic environment when compared to MoS2 and WS2. These results can also be used to mechanistically explain fate, transport, transformation, organismal uptake, and toxicity of inorganic 2D NMs in the natural ecosystems. ? 2019 American Chemical Society. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85064960228&doi=10.1021%2facs.est.8b05180&partnerID=40&md5=eeb6ff0a20a7ce02634f8a69fbb27f55 https://scholars.lib.ntu.edu.tw/handle/123456789/611473 |
DOI: | 10.1021/acs.est.8b05180 |
顯示於: | 化學工程學系 |
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