Ab initio comparative study of montmorillonite structural models

Minisini, Benoît; Tsobnang, F.

doi:10.1016/j.apsusc.2004.07.057

Cited by 19 publications

(11 citation statements)

References 36 publications

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“…1. [29][30][31][32][33] Recently, the first ab initio MD (AIMD) simulation study on the hydration of sodium montmorillonite (tetrahedral substituted, T sub ) has been carried out. Classical methods showed that the swelling process occurs by increasing the water content through the formation of 1, 2 and 3 layer hydrates, the basal spacing ranging between B12 and 18-19 Å depending on the method used, the type of clay (chemical composition, i.e.…”

Section: Introductionmentioning

confidence: 99%

Ab initio molecular dynamics study of the hydration of Li+, Na+ and K+ in a montmorillonite model. Influence of isomorphic substitution

Mignon

Ugliengo

Sodupe

et al. 2010

Phys. Chem. Chem. Phys.

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The present work reports ab initio molecular dynamics simulations, based on density functional theory using the PBE functional, of Li(+)- Na(+)- and K(+)-montmorillonites, considering three types of isomorphic substitutions in the montmorillonite layer: tetrahedral (T(sub)), octahedral (O(sub)) and both (OT(sub)). These simulations allow us to evaluate the effect of each type of substitution on the inner- outer-sphere complex formation of the alkali cations. It is observed that, for the three kinds of substituted montmorillonites, K(+) remains bound to the surface confirming its role as swelling inhibitor. In contrast, Li(+) tends to hydrate and coordinate to 4 water molecules in all cases, except for OT(sub), for which one of the two Li(+) cations remains bound to the oxygens close to the substituted tetrahedral site. Finally, Na(+) presents an intermediate behaviour, binding to the surface in T(sub) montmorillonite but being hydrated in O(sub). These simulations show that the hydration/adsorption behaviour of alkali cations in the swelling process of montmorillonite depends on the affinity of the cation for water and the surface, as well as on the type of substitution that controls the negative charge on surface oxygen atoms.

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Section: Introductionmentioning

confidence: 99%

Ab initio molecular dynamics study of the hydration of Li+, Na+ and K+ in a montmorillonite model. Influence of isomorphic substitution

Mignon

Ugliengo

Sodupe

et al. 2010

Phys. Chem. Chem. Phys.

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“…Quantum-mechanical calculations of different compositions and cation configurations of 2:1 dioctahedral phyllosilicates in the cis-vacant polymorph showed that the VI Mg 21 , VI Fe 31 , and IV Al 31 isomorphous substitutions follow the same trends than in the trans-vacant polymorphs. [23,24] Considering all these experimental and computational results, it is difficult to draw definitive conclusions for the cation ordering in these minerals.…”

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confidence: 99%

Computer simulations of cations order‐disorder in 2:1 dioctahedral phyllosilicates using cation‐exchange potentials and monte carlo methods

Palin

Dove

Redfern

et al. 2014

Int J of Quantum Chemistry

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This article reviews the use of Monte Carlo methods with cation-exchange potentials and effective Hamiltonians, based on empirical potentials and quantum-mechanical calculations, for the study of cation ordering in phyllosilicates. The basic methodology is described, and the application of the methods is illustrated with a number of key example case studies. These include Al-Si ordering in muscovite, Al-Fe-Mg ordering (both binary and ternary compositions) in the octahedral illite/smectite sheet, examination of the ordering behavior of phengite, in which the octahedral sites are occupied by Al and Mg and the tetrahedral sites by Al and Si, and Al-Si ordering in the tetrahedral phyllosilicate sheet with variable Al:Si ratio. In several cases, complex ordering processes were found. The essential conclusion from this work is that computer simulation studies of this nature can be a valuable tool in ordering studies of many nanomaterials.

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“…The initial MMT structure was generated using the Crystal Builder of Accelrys Material Studio package which offers the optimized trans ‐Na‐MMT structure taken from the X‐ray diffraction (XRD) data . Plane‐wave pseudopotential density functional theory code CASTEP with PW91 functional and ultra‐soft Vanderbilt potentials was used to optimize unit cell of the trans ‐vacant MMT (Figure ) according to the procedure by Minisini and Tsobnang …”

Section: Methodsmentioning

confidence: 99%

Experimental and MD simulation study on the physical and mechanical properties of organically modified montmorillonite clay and compatibilized linear low density polyethylene nanocomposites

Yıldırım

Yurtsever

Eriman

et al. 2017

J of Applied Polymer Sci

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Understanding the interfacial interactions plays a key role in controlling mechanical and physical properties of polymer/ clay nanocomposites (PCNs). In this work, the surface interactions between constituents of experimentally prepared PCNs which are the pristine linear low density polyethylene (PE) chains, PE compatibilizers, montmorillonite clay surface layer, and surfactants were studied quantitatively by employing molecular dynamics simulation technique. The interaction energy between the polymer and the clay was found to be inversely proportional with the volume of the surfactant which decreases the electrostatic interactions between the compatibilizer and the hydrophilic clay surface. However, the van der Waals (vdW) interactions between alkyl tails of surfactants and the PE chains increase with the tail length of the surfactants. The most attractive interaction was between the surfactant's head group and the clay surface. We showed that there existed fine balance between the electrostatic and vdW type forces on the stability and the enhanced properties of the PE-organoclay nanocomposites. Calculated interaction energies were then correlated to the experimentally measured mechanical properties.

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Ab initio comparative study of montmorillonite structural models

Cited by 19 publications

References 36 publications

Ab initio molecular dynamics study of the hydration of Li+, Na+ and K+ in a montmorillonite model. Influence of isomorphic substitution

Ab initio molecular dynamics study of the hydration of Li+, Na+ and K+ in a montmorillonite model. Influence of isomorphic substitution

Computer simulations of cations order‐disorder in 2:1 dioctahedral phyllosilicates using cation‐exchange potentials and monte carlo methods

Experimental and MD simulation study on the physical and mechanical properties of organically modified montmorillonite clay and compatibilized linear low density polyethylene nanocomposites

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