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Zhang Y, Oestreicher J, Binns WJ, Briggs S, Kim CS, Béland LK. A Coarse-Grained Interaction Model for Sodium Dominant Montmorillonite. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:13226-13237. [PMID: 36256513 DOI: 10.1021/acs.langmuir.2c02233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Montmorillonite is the main crystalline mineral present in bentonite. It is an absorbent, swelling material; the physical chemistry underlying its ability to absorb water and swell occurs at the nanoscale, governed by electrical double-layer interactions. In turn, absorption and swelling lead to important changes in the macroscopic transport properties of the clay. Mesoscale models can help us establish a link between these nanoscale processes and macroscale properties, notably by providing a detailed description of its pore network. Models on the scale of hundreds to thousands of nanometers are required, which cannot realistically be handled using traditional all-atom molecular dynamics simulations. This work presents a coarse-grained (CG) mesoscale model of sodium montmorillonite. In our model, montmorillonite platelets are represented by two types of particles: central nonhydrogen-bonded particles and edge hydrogen-bonding particles. The particle interactions are described by two-body potentials, which were optimized based on all-atom molecular dynamics simulations. Specifically, several potential mean force calculations involving dry and hydrated montmorillonite were performed, using the ClayFF potential to calculate interatomic forces. The CG model was validated by testing the scalability of the model, testing its ability to reproduce potentials of mean force reported elsewhere in the literature, and by comparing the calculated elastic properties of a system containing 1000 Na montmorillonite platelets to experimentally measured elastic properties of bentonite. The simulated elastic properties obtained using our mesoscale model agree with these experimental values.
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Affiliation(s)
- Yaoting Zhang
- Department of Mechanical & Materials Engineering, Queen's University, Nicol Hall, 60 Union Street, Kingston, K7L 3N6Ontario, Canada
- Nuclear Waste Management Organization, 22 St. Clair Avenue East Fourth Floor, Toronto, M4T 2S3Ontario, Canada
| | - Jeremy Oestreicher
- Department of Mechanical & Materials Engineering, Queen's University, Nicol Hall, 60 Union Street, Kingston, K7L 3N6Ontario, Canada
| | - W Jeffrey Binns
- Nuclear Waste Management Organization, 22 St. Clair Avenue East Fourth Floor, Toronto, M4T 2S3Ontario, Canada
| | - Scott Briggs
- Nuclear Waste Management Organization, 22 St. Clair Avenue East Fourth Floor, Toronto, M4T 2S3Ontario, Canada
| | - Chang Seok Kim
- Nuclear Waste Management Organization, 22 St. Clair Avenue East Fourth Floor, Toronto, M4T 2S3Ontario, Canada
| | - Laurent K Béland
- Department of Mechanical & Materials Engineering, Queen's University, Nicol Hall, 60 Union Street, Kingston, K7L 3N6Ontario, Canada
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Peng C, Wang G, Zhang C, Qin L, Zhu X, Luo S. Molecular dynamics simulation of NH4+-smectite interlayer hydration: Influence of layer charge density and location. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116232] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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3
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Liu Q, Zhang X, Jiang B, Li J, Li T, Shao X, Cai W, Wang H, Zhang Y. Molecular Dynamics Simulation of Ion Adsorption and Ligand Exchange on an Orthoclase Surface. ACS OMEGA 2021; 6:14952-14962. [PMID: 34151076 PMCID: PMC8209803 DOI: 10.1021/acsomega.1c00826] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/26/2021] [Indexed: 05/31/2023]
Abstract
Orthoclase (K-feldspar) is one of the natural inorganic materials, which shows remarkable potential toward removing heavy metal ions from aqueous solutions. Understanding the interactions of the orthoclase and metal ions is important in the treatment of saline wastewater. In this paper, molecular dynamics simulations were used to prove the adsorption of different ions onto orthoclase. The adsorption isotherms show that orthoclase has remarkable efficiency in the removal of cations at low ion concentrations. Aluminol groups are the preferential adsorption sites of cations due to higher negative charges. The adsorption types and adsorption sites are influenced by the valence, radius, and hydration stability of ions. Monovalent cations can be adsorbed in the cavities, whereas divalent cations cannot. The hydrated cation may form an outer-sphere complex or an inner-sphere complex in association with the loss of hydration water. Na+, K+, and Ca2+ ions mainly undergo inner-sphere adsorption and Mg2+ ions prefer outer-sphere adsorption. On the basis of simulation results, the mechanism of ion removal in the presence of orthoclase is demonstrated at a molecular level.
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Affiliation(s)
- Qian Liu
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Xuan Zhang
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Binbin Jiang
- State
Key Laboratory of Water Resource Protection and Utilization in Coal
Mining, Beijing 100011, China
| | - Jingfeng Li
- State
Key Laboratory of Water Resource Protection and Utilization in Coal
Mining, Beijing 100011, China
| | - Ting Li
- State
Key Laboratory of Water Resource Protection and Utilization in Coal
Mining, Beijing 100011, China
| | - Xianzhen Shao
- Hekou
Oil Production Plant of Shengli Oilfield, Sinopec, Dongying, Shandong 257200, China
| | - Weibin Cai
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Hongyuan Wang
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
| | - Yuankun Zhang
- School
of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China
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Mitra S, Sharma VK, Mukhopadhyay R. Diffusion of confined fluids in microporous zeolites and clay materials. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:066501. [PMID: 33740783 DOI: 10.1088/1361-6633/abf085] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Fluids exhibit remarkable variation in their structural and dynamic properties when they are confined at the nanoscopic scale. Various factors, including geometric restriction, the size and shape of the guest molecules, the topology of the host, and guest-host interactions, are responsible for the alterations in these properties. Due to their porous structures, aluminosilicates provide a suitable host system for studying the diffusion of sorbates in confinement. Zeolites and clays are two classes of the aluminosilicate family, comprising very ordered porous or layered structures. Zeolitic materials are important due to their high catalytic activity and molecular sieving properties. Guest molecules adsorbed by zeolites display many interesting features including unidimensional diffusion, non-isotropic rotation, preferred orientation and levitation effects, depending on the guest and host characteristics. These are useful for the separation of hydrocarbons which commonly exist as mixtures in nature. Similarly, clay materials have found application in catalysis, desalination, enhanced oil recovery, and isolation barriers used in radioactive waste disposal. It has been shown that the bonding interactions, level of hydration, interlayer spacing, and number of charge-balancing cations are the important factors that determine the nature of diffusion of water molecules in clays. Here, we present a review of the current status of the diffusion mechanisms of various adsorbed species in different microporous zeolites and clays, as investigated using quasielastic neutron scattering and classical molecular dynamics simulation techniques. It is impossible to write an exhaustive review of the subject matter, as it has been explored over several decades and involves many research topics. However, an effort is made to cover the relevant issues specific to the dynamics of different molecules in microporous zeolites and clay materials and to highlight a variety of interesting features that are important for both practical applications and fundamental aspects.
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Affiliation(s)
- S Mitra
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - V K Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - R Mukhopadhyay
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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Abstract
Sorption of chemicals onto soil particle surfaces is an important process controlling their availability for uptake by organisms and loss from soils to ground and surface waters. The mechanisms of chemical sorption are inner- and outer-sphere adsorption and precipitation onto mineral surfaces. Factors that determine the sorption behavior are properties of soil mineral and organic matter surfaces and properties of the sorbing chemicals (including valence, electron configuration, and hydrophobicity). Because soils are complex heterogeneous mixtures, measuring sorption mechanisms is challenging; however, advancements analytical methods have made direct determination of sorption mechanisms possible. In this review, historical and modern research that supports the mechanistic understanding of sorption mechanisms in soils is discussed. Sorption mechanisms covered include cation exchange, outer-sphere adsorption, inner-sphere adsorption, surface precipitation, and ternary adsorption complexes.
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Chen H, Li Q, Wang M, Ji D, Tan W. XPS and two-dimensional FTIR correlation analysis on the binding characteristics of humic acid onto kaolinite surface. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 724:138154. [PMID: 32272401 DOI: 10.1016/j.scitotenv.2020.138154] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 03/12/2020] [Accepted: 03/22/2020] [Indexed: 06/11/2023]
Abstract
The stabilization and preservation of soil organic matter have been attributed to the strong reactive sites of mineral surfaces that cause physical isolation and chemical stabilization due to the organic-mineral interface. However, much of the micro-scale knowledge about interactions between organic ligands and minerals largely remains at the qualitative level, and neglects the heterogeneity of functional groups of organic matter. Here, we report the use of molecular-scale technologies of two-dimensional FTIR Correlation Spectroscopy (2D-FTIR-CoS) and X-ray Photoelectron Spectroscopy (XPS) to directly measure the binding processes of humic acid (JGHA) groups onto kaolinite surface. The spectroscopy results showed that the carboxylate groups, aliphatic OH and aromatic structure participate in the binding of JGHA on kaolinite surface. The carboxylic and phenolic hydroxyl interact with kaolinite surface through the interfacial COAl/Si bonds. Kaolinite prefers to adsorb C-groups at pH 4.0 and O-groups at pH 8.0. The interaction of COO- group at 1566 cm-1 of JGHA leads to the formation of inner-sphere complex first and then outer-sphere complex with increasing contact time. The interaction of COOH group at 1261 cm-1 with the AlOH2+ of kaolinite was could be ascribed to ligand exchange and/or electrostatic attraction, whose contribution was evaluated to be 13.90%, 7.65% and 0% at pH 4.0, 6.0 and 8.0, respectively. These results of molecular binding provide quantitative mechanistic insights into organic-mineral interactions and expound the effect of functional groups of HA on binding mechanisms, and thus bring important clues for better understanding the mobility and transformation of land‑carbon including mineral-bound carbon.
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Affiliation(s)
- Hongfeng Chen
- College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002, PR China; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Qi Li
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Mingxia Wang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Daobin Ji
- College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002, PR China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China.
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7
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Ho TA, Greathouse JA, Wang Y, Criscenti LJ. Atomistic Structure of Mineral Nano-aggregates from Simulated Compaction and Dewatering. Sci Rep 2017; 7:15286. [PMID: 29127405 PMCID: PMC5681677 DOI: 10.1038/s41598-017-15639-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/31/2017] [Indexed: 11/22/2022] Open
Abstract
The porosity of clay aggregates is an important property governing chemical reactions and fluid flow in low-permeability geologic formations and clay-based engineered barrier systems. Pore spaces in clays include interlayer and interparticle pores. Under compaction and dewatering, the size and geometry of such pore spaces may vary significantly (sub-nanometer to microns) depending on ambient physical and chemical conditions. Here we report a molecular dynamics simulation method to construct a complex and realistic clay-like nanoparticle aggregate with interparticle pores and grain boundaries. The model structure is then used to investigate the effect of dewatering and water content on micro-porosity of the aggregates. The results suggest that slow dewatering would create more compact aggregates compared to fast dewatering. Furthermore, the amount of water present in the aggregates strongly affects the particle-particle interactions and hence the aggregate structure. Detailed analyses of particle-particle and water-particle interactions provide a molecular-scale view of porosity and texture development of the aggregates. The simulation method developed here may also aid in modeling the synthesis of nanostructured materials through self-assembly of nanoparticles.
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Affiliation(s)
- Tuan Anh Ho
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA.
| | - Jeffery A Greathouse
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA
| | - Yifeng Wang
- Nuclear Waste Disposal Research and Analysis Department, Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA
| | - Louise J Criscenti
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico, 87185, USA.
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8
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Li X, Li H, Yang G. Electric fields within clay materials: How to affect the adsorption of metal ions. J Colloid Interface Sci 2017; 501:54-59. [PMID: 28433885 DOI: 10.1016/j.jcis.2017.04.040] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/05/2017] [Accepted: 04/09/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Xiong Li
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Hang Li
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environment & Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China.
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9
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Xu J, Camara M, Liu J, Peng L, Zhang R, Ding T. Molecular dynamics study of the swelling patterns of Na/Cs-, Na/Mg-montmorillonites and hydration of interlayer cations. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2016.1274982] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Jiafang Xu
- School of Petroleum Engineering, China University of Petroleum, Qingdao, P.R. China
| | - Moussa Camara
- School of Petroleum Engineering, China University of Petroleum, Qingdao, P.R. China
| | - Jinxiang Liu
- School of Physics and Technology, University of Jinan, Jinan, P.R. China
| | - Lin Peng
- School of Petroleum Engineering, China University of Petroleum, Qingdao, P.R. China
| | - Rui Zhang
- School of Petroleum Engineering, China University of Petroleum, Qingdao, P.R. China
| | - Tingji Ding
- School of Petroleum Engineering, China University of Petroleum, Qingdao, P.R. China
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Yan KF, Li XS, Chen ZY, Xia ZM, Xu CG, Zhang Z. Molecular Dynamics Simulation of the Crystal Nucleation and Growth Behavior of Methane Hydrate in the Presence of the Surface and Nanopores of Porous Sediment. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:7975-7984. [PMID: 27398713 DOI: 10.1021/acs.langmuir.6b01601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The behavior of hydrate formation in porous sediment has been widely studied because of its importance in the investigation of reservoirs and in the drilling of natural gas hydrate. However, it is difficult to understand the hydrate nucleation and growth mechanism on the surface and in the nanopores of porous media by experimental and numerical simulation methods. In this work, molecular dynamics simulations of the nucleation and growth of CH4 hydrate in the presence of the surface and nanopores of clay are carried out. The molecular configurations and microstructure properties are analyzed for systems containing one H2O hydrate layer (System A), three H2O hydrate layers (System B), and six H2O hydrate layers (System C) in both clay and the bulk solution. It is found that hydrate formation is more complex in porous media than in the pure bulk solution and that there is cooperativity between hydrate growth and molecular diffusion in clay nanopores. The hydroxylated edge sites of the clay surface could serve as a source of CH4 molecules to facilitate hydrate nucleation. The diffusion velocity of molecules is influenced by the growth of the hydrate that forms a block in the throats of the clay nanopore. Comparing hydrate growth in different clay pore sizes reveals that the pore size plays an important role in hydrate growth and molecular diffusion in clay. This simulation study provides the microscopic mechanism of hydrate nucleation and growth in porous media, which can be favorable for the investigation of the formation of natural gas hydrate in sediments.
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Affiliation(s)
- Ke-Feng Yan
- Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640, China
- Guangdong Key Laboratory of New and Renewable Energy Research and Development , Guangzhou 510640, China
| | - Xiao-Sen Li
- Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640, China
- Guangdong Key Laboratory of New and Renewable Energy Research and Development , Guangzhou 510640, China
| | - Zhao-Yang Chen
- Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640, China
- Guangdong Key Laboratory of New and Renewable Energy Research and Development , Guangzhou 510640, China
| | - Zhi-Ming Xia
- Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640, China
- Guangdong Key Laboratory of New and Renewable Energy Research and Development , Guangzhou 510640, China
| | - Chun-Gang Xu
- Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences , Guangzhou 510640, China
- Guangdong Key Laboratory of New and Renewable Energy Research and Development , Guangzhou 510640, China
| | - Zhiqiang Zhang
- College of Mining Engineering, Taiyuan University of Technology , Taiyuan 030024, China
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11
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Li X, Li H, Yang G. Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study. Sci Rep 2015; 5:14377. [PMID: 26403873 PMCID: PMC4585903 DOI: 10.1038/srep14377] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 08/25/2015] [Indexed: 11/26/2022] Open
Abstract
Defect sites exist abundantly in minerals and play a crucial role for a variety of important processes. Here molecular dynamics simulations are used to comprehensively investigate the adsorption behaviors, stabilities and mechanisms of metal ions on defective minerals, considering different ionic concentrations, defect sizes and contents. Outer-sphere adsorbed Pb2+ ions predominate for all models (regular and defective), while inner-sphere Na+ ions, which exist sporadically only at concentrated solutions for regular models, govern the adsorption for all defective models. Adsorption quantities and stabilities of metal ions on kaolinite are fundamentally promoted by defect sites, thus explaining the experimental observations. Defect sites improve the stabilities of both inner- and outer-sphere adsorption, and (quasi) inner-sphere Pb2+ ions emerge only at defect sites that reinforce the interactions. Adsorption configurations are greatly altered by defect sites but respond weakly by changing defect sizes or contents. Both adsorption quantities and stabilities are enhanced by increasing defect sizes or contents, while ionic concentrations mainly affect adsorption quantities. We also find that adsorption of metal ions and anions can be promoted by each other and proceeds in a collaborative mechanism. Results thus obtained are beneficial to comprehend related processes for all types of minerals.
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Affiliation(s)
- Xiong Li
- College of Resources and Environment &Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Hang Li
- College of Resources and Environment &Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
| | - Gang Yang
- College of Resources and Environment &Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, Southwest University, Chongqing 400715, China
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Duarte D, Salanne M, Rotenberg B, Bizeto MA, Siqueira LJA. Structure of tetraalkylammonium ionic liquids in the interlayer of modified montmorillonite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:284107. [PMID: 24920411 DOI: 10.1088/0953-8984/26/28/284107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We perform molecular dynamics simulations of tetraalkylammonium ionic liquids confined in the interlayer of montmorillonite (MMT). We study the structure and energetics of the systems, which consist of cations with two different alkyl chain lengths and several ionic liquid concentrations. The results we obtained for the structure, namely the presence of a strong layering in all systems and the formation of nonpolar domains with interdigitated alkyl chains in some cases, are largely consistent with previous surface force balance experiments performed on similar systems. Finally, we show that swelling of the organo-modified MMT by a large amount of ionic liquid seems energetically favorable in all cases.
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Affiliation(s)
- Daniel Duarte
- Laboratório de Materiais Híbridos, Departamento de Ciências Exatas e da Terra, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, CEP 09913-030, Diadema, SP, Brazil
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14
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Salles F, Douillard JM, Bildstein O, Gaudin C, Prelot B, Zajac J, Van Damme H. Driving force for the hydration of the swelling clays: case of montmorillonites saturated with alkaline-earth cations. J Colloid Interface Sci 2013; 395:269-76. [PMID: 23352873 DOI: 10.1016/j.jcis.2012.12.050] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/20/2012] [Accepted: 12/21/2012] [Indexed: 11/15/2022]
Abstract
Important structural modifications occur in swelling clays upon water adsorption. The multi-scale evolution of the swelling clay structure is usually evidenced by various experimental techniques. However, the driving force behind such phenomena is still not thoroughly understood. It appears strongly dependent on the nature of the interlayer cation. In the case of montmorillonites saturated with alkaline cations, it was inferred that the compensating cation or the layer surface could control the hydration process and thus the opening of the interlayer space, depending on the nature of the interlayer cation. In the present study, emphasis is put on the impact of divalent alkaline-earth cations compensating the layer charge in montmorillonites. Since no experimental technique offers the possibility of directly determining the hydration contributions related to interlayer cations and layer surfaces, an approach based on the combination of electrostatic calculations and immersion data is developed here, as already validated in the case of montmorillonites saturated by alkaline cations. This methodology allows to estimate the hydration energy for divalent interlayer cations and therefore to shed a new light on the driving force for hydration process occurring in montmorillonites saturated with alkaline-earth cations. Firstly, the surface energy values obtained from the electrostatic calculations based on the Electronegativity Equalization Method vary from 450 mJ m(-2) for Mg-montmorillonite to 1100 mJ m(-2) for Ba-montmorillonite. Secondly, considering both the hydration energy for cations and layer surfaces, the driving force for the hydration of alkaline-earth saturated montmorillonites can be attributed to the interlayer cation in the case of Mg-, Ca-, Sr-montmorillonites and to the interlayer surface in the case of Ba-montmorillonites. These results explain the differences in behaviour upon water adsorption as a function of the nature of the interlayer cation, thereby allowing the macroscopic swelling trends to be better understood. The knowledge of hydration processes occurring in homoionic montmorillonites saturated with both the alkaline and the alkaline-earth cations may be of great importance to explain the behaviour of natural clay samples where mixtures of the two types of interlayer cation are present and also provides valuable information on the cation exchange occurring in the swelling clays.
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Affiliation(s)
- Fabrice Salles
- Institut Charles Gerhardt, UMR 5253, CNRS-UM2-ENSCM-UM1, Université Montpellier II, Montpellier, France.
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15
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Yan W, Zhang J, Jing C. Adsorption of Enrofloxacin on montmorillonite: Two-dimensional correlation ATR/FTIR spectroscopy study. J Colloid Interface Sci 2013; 390:196-203. [DOI: 10.1016/j.jcis.2012.09.039] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 09/10/2012] [Accepted: 09/17/2012] [Indexed: 11/26/2022]
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16
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Bonnaud PA, Coasne B, Pellenq RJM. Solvated calcium ions in charged silica nanopores. J Chem Phys 2012; 137:064706. [DOI: 10.1063/1.4742854] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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