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Molecular Dynamic (MD) Simulations of Organic Modified Montmorillonite. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app12010314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study complements the knowledge about organobentonites, which are intended to be new binders in foundry technology. In the developed materials, acrylic polymers act as mineral modifying compounds. Modification of montmorillonite in bentonite was carried out in order to obtain a composite containing a polymer as a lustrous carbon precursor. The polymer undergoes thermal degradation during the casting process, which results in the formation of this specific carbon form, ensuring the appropriate quality of the casting surface without negative environmental impact. The present paper reports the results of computational simulation studies (LAMMPS software) aimed at broadening the knowledge of interactions of organic molecules in the form of acrylic acid and acrylate anions (from sodium acrylate) near the montmorillonite surface, which is a simplified model of bentonite/acrylic polymer systems. It has been proven that the –COOH group promotes the adsorption of acrylic acid (AA) to the mineral surface, while acrylate ions tend to be unpredictably scattered, which may be related to the electrostatic repulsion between anions and negatively charged clay surfaces. The simulation results are consistent with the results of structural tests carried out for actual organobentonites. It has been proven that the polymer mainly adsorbs on the mineral surface, although it also partially intercalates into the interlayer spaces of the montmorillonite. This comprehensive research approach is innovative in the engineering of foundry materials. Computer simulation methods have not been used in the production of new binding materials in molding sand technology so far.
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Zhang S, Liu Q, Gao F, Ma R, Wu Z, Teppen BJ. Interfacial Structure and Interaction of Kaolinite Intercalated with N-methylformamide Insight from Molecular Dynamics Modeling. APPLIED CLAY SCIENCE 2018; 158:204-210. [PMID: 30364591 PMCID: PMC6197067 DOI: 10.1016/j.clay.2018.03.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The evolution of basal spacing and interfacial structure of kaolinite-N-methylformamide (NMF) complexes during the intercalation process were difficult to obtain using experimental methods. In present study, a series of kaolinite-NMF complex models with various numbers of NMF molecules in the interlayer space were constructed to mimic the progressive stage of the intercalation process of kaolinite intercalated by NMF. The MD simulations were performed on these models to explore the evolution of basal spacing and interfacial structure of kaolinite-NMF complexes during the intercalation process. It was found that the basal spacing of complex was stabilized at 11 Å during the intercalation process, where the molecular plane of NMF oriented at small angles with respect to the interlayer surface with the C=O groups and N-H bonds pointing toward the octahedral and tetrahedral surfaces, respectively, due to the hydrogen bonding interactions. The basal spacing can be enlarged to larger values with the prerequisite of overcoming the energy barrier. With the increase of basal spacing during the intercalation process, the NMF were rearranged as a pillar with the molecular planes orienting at higher angles with respect to the interlayer surface, and then developed to disordered bilayer structure. For the interfacial interaction of kaolinite-NMF complex, both the octahedral surface and tetrahedral surface showed binding affinity to the NMF, which is the driving force for the intercalation of NMF in kaolinite. The octahedral surface displays stronger binding affinity to the NMF in terms of the H-bonds and energetics compared to the tetrahedral surface partially due to the highly active surface hydroxyl groups. The present study provides insight into the basal spacing evolution, and interfacial structure and interaction of kaolinite-NMF complexes, which can enhance the understanding of kaolinite intercalated by small molecules.
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Affiliation(s)
- Shuai Zhang
- College of Geoscience and Surveying Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People’s Republic of China
| | - Qinfu Liu
- College of Geoscience and Surveying Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People’s Republic of China
| | - Feng Gao
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, United States
| | - Rujia Ma
- College of Geoscience and Surveying Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People’s Republic of China
| | - Zeguang Wu
- School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, People’s Republic of China
| | - Brian J. Teppen
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, United States
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Zhang S, Liu Q, Gao F, Teppen BJ. Molecular Dynamics Simulation of Basal Spacing, Energetics, and Structure Evolution of a Kaolinite-Formamide Intercalation Complex and Their Interfacial Interaction. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2018; 122:3341-3349. [PMID: 29657662 PMCID: PMC5896007 DOI: 10.1021/acs.jpcc.7b10234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Molecular dynamics simulations were performed on kaolinite-formamide complex models with various numbers of formamide molecules loaded in the kaolinite interlayer to explore the basal spacing, energetics, and structure evolution of the kaolinite-formamide complex during the intercalation process. Additionally, the interfacial interactions of formamide with kaolinite interlayer surfaces were calculated. The calculation revealed that the basal spacing of kaolinite was enlarged to 9.6 Å at the beginning of intercalation. Formamide was arranged as a monolayer structure in the kaolinite interlayer with the molecular plane oriented at small angles with respect to the interlayer surface. With continuous intercalation, the basal spacing readily reached a stable stage at 10.6 Å, where formamide rearranged its structure by rotating the molecule plane along the C-N bond that was parallel to the interlayer surface, which resulted in the molecular plane orienting at higher angles with respect to the interlayer surface. During this process, the C═O groups oriented toward the hydroxyl groups on the interlayer octahedral surface, and one of N-H bonds progressively pointed toward the basal oxygens on the opposing interlayer tetrahedral surface. Continuous intercalation can enlarge the basal spacing to more than 14 Å with the prerequisite of overcoming the energy barrier, and then formamide evolved to a disordered bilayer structure in the kaolinite interlayer. The affinity of kaolinite interlayer surfaces for formamide motivated the intercalation process. The octahedral surface displayed a relatively larger affinity toward formamide compared to the tetrahedral surface partially due to the presence of hydroxyl groups that are more active in the intermolecular interactions with formamide.
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Affiliation(s)
- Shuai Zhang
- College of Geoscience and Surveying Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People’s Republic of China
| | - Qinfu Liu
- College of Geoscience and Surveying Engineering, China University of Mining & Technology (Beijing), Beijing 100083, People’s Republic of China
| | - Feng Gao
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, United States
| | - Brian J. Teppen
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, Michigan 48824, United States
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Ható Z, Rutkai G, Vrabec J, Kristóf T. Communication: Molecular simulation study of kaolinite intercalation with realistic layer size. J Chem Phys 2014; 141:091102. [PMID: 25194356 DOI: 10.1063/1.4894756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Intercalation phenomena of kaolinite in aqueous potassium acetate and in hexyl-amine solutions are studied by large scale molecular dynamics simulations. The simulated kaolinite particle is constructed from ~6.5 × 10(6) atoms, producing a particle size of ~100 nm × 100 nm × 10 nm. The simulation with potassium acetate results in a stable kaolinite-potassium acetate complex, with a basal spacing that is in close agreement with experimental data. The simulation with hexyl-amine shows signs of the experimentally observed delamination of kaolinite (the initial phase of the formation of nanoscrolls from the external layers).
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Affiliation(s)
- Zoltán Ható
- Institute of Chemistry, Department of Physical Chemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
| | - Gábor Rutkai
- Thermodynamics and Energy Technology (ThEt), University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Jadran Vrabec
- Thermodynamics and Energy Technology (ThEt), University of Paderborn, Warburger Str. 100, D-33098 Paderborn, Germany
| | - Tamás Kristóf
- Institute of Chemistry, Department of Physical Chemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary
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Makó É, Kovács A, Ható Z, Zsirka B, Kristóf T. Characterization of kaolinite-ammonium acetate complexes prepared by one-step homogenization method. J Colloid Interface Sci 2014; 431:125-31. [PMID: 24996021 DOI: 10.1016/j.jcis.2014.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 10/25/2022]
Abstract
Although kaolinite-ammonium acetate complexes are of interest in the area of kaolinite nanocomposites, the structures of these complexes have remained largely elusive. Experimental and molecular simulation analysis is used to investigate their structures, revealing that two types of water-containing kaolinite-ammonium acetate complex exist. A cost-efficient one-step homogenization method was used to synthesize these complexes. The effect of the aging time and the amount of reagents on the intercalation were characterized experimentally by X-ray diffraction, thermogravimetry, Fourier transform infrared spectroscopy and scanning electron microscopy. The optimal degree of intercalation was obtained by using two orders of magnitude lower amount of reagents than in the case of the solution method. It was found that the so far less investigated 1.7-nm complex has higher water content than the 1.4-nm one. For both complexes, our molecular simulations predict the double-layered structure of the acetate ions, which is usually assumed in the case of the kaolinite-acetate complexes. For the 1.7-nm complex, however, a quasi-triple-layered structure of water molecules instead of the double-layered one was calculated.
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Affiliation(s)
- Éva Makó
- Institute of Materials Engineering, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary.
| | - András Kovács
- Institute of Materials Engineering, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary.
| | - Zoltán Ható
- Institute of Chemistry, Department of Physical Chemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary.
| | - Balázs Zsirka
- Institute of Environmental Engineering, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary.
| | - Tamás Kristóf
- Institute of Chemistry, Department of Physical Chemistry, University of Pannonia, P.O. Box 158, H-8201 Veszprém, Hungary.
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Táborosi A, Kurdi R, Szilágyi RK. The positions of inner hydroxide groups and aluminium ions in exfoliated kaolinite as indicators of the external chemical environment. Phys Chem Chem Phys 2014; 16:25830-9. [DOI: 10.1039/c4cp03566f] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New insights: a molecular cluster model was created for exfoliated kaolinite using coordination chemistry principles highlighting the remarkable structural differences relative to crystalline kaolinite.
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Affiliation(s)
- Attila Táborosi
- Department of Environmental Engineering
- Faculty of Engineering
- University of Pannonia
- Veszprém, Hungary
| | - Róbert Kurdi
- Department of Environmental Engineering
- Faculty of Engineering
- University of Pannonia
- Veszprém, Hungary
| | - Róbert K. Szilágyi
- Department of Analytical Chemistry
- Faculty of Engineering
- University of Pannonia
- Veszprém, Hungary
- Department of Chemistry and Biochemistry
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