Uranyl adsorption on (001) surfaces of kaolinite: A molecular dynamics study

Yang, Wei; Zaoui, A.

doi:10.1016/j.clay.2013.04.007

Cited by 45 publications

(23 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Two adsorption modes (inner- and outer-sphere) were proposed for the interaction of metal ions with clay minerals 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 . Inner-sphere metal ions form stable complexes directly with clay minerals, while outer-sphere ones are separated from clay minerals by an intermediate water molecule.…”

mentioning

confidence: 99%

Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

Yang

2015

Sci Rep

View full text Add to dashboard Cite

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.

show abstract

mentioning

confidence: 99%

Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

Yang

2015

Sci Rep

View full text Add to dashboard Cite

show abstract

“…To describe the Montmorillonite (001)/calcite (104) interface, we have developed existing models for calcite and clay by adding terms describing the interatomic interactions between constituents of calcite and clay at the interface. We have used the ClayFF potential model 37 , well tested for clays 38 39 40 41 42 43 44 45 46 47 48 49 and the Xiao forcefield for calcite 50 , that we have previously used in the analysis of bulk and surface state of calcite rock 51 . This is a new forcefield taking into account the aqueous environment using the TIP3P water model 52 .…”

Section: Methods Summarymentioning

confidence: 99%

Can clays ensure nuclear waste repositories?

Zaoui

Sekkal

2015

Sci Rep

Self Cite

View full text Add to dashboard Cite

Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

show abstract

“…Some of our previous works have been devoted to clay systems in order to understand the swelling and shrinking behaviors [6,7], the diffusion of cations in interlayer space [8,9], the thermodynamic and mechanical properties of clays [10][11][12][13], the interaction between radionucleides and clay surface [14,15] and pressure effect on the clay portions [16]. More recent studies have addressed the mechanical properties of nanocomposites using experiment and classical approaches [17,18] as well as molecular dynamics simulations [19].…”

Section: Molecular Dynamics (Md) Studies Of Interactions Among Constimentioning

confidence: 99%

Structural and thermodynamics properties of organo-modified montmorillonite clay

Anoukou¹,

Zaoui²,

Zaïri³

et al. 2015

Physica E: Low-dimensional Systems and Nanostructures

Self Cite

View full text Add to dashboard Cite

Uranyl adsorption on (001) surfaces of kaolinite: A molecular dynamics study

Cited by 45 publications

References 24 publications

Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

Promoting the Adsorption of Metal Ions on Kaolinite by Defect Sites: A Molecular Dynamics Study

Can clays ensure nuclear waste repositories?

Structural and thermodynamics properties of organo-modified montmorillonite clay

Contact Info

Product

Resources

About