کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6971908 1453098 2013 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Behind adhesion of uranyl onto montmorillonite surface: A molecular dynamics study
ترجمه فارسی عنوان
پشت چسبندگی اورانیل به سطح مونتموریلونیت: مطالعه دینامیک مولکولی
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بهداشت و امنیت شیمی
چکیده انگلیسی
We have performed molecular dynamics simulations to investigate the adsorption of radionuclide elements species onto substituted Montmorillonite (001) surface in the presence of different counterions. The structure and the dynamics of uranyl ion as well as its aquo, chloride ion, and carbonate complexes are analyzed. In addition, we have studied the surface energy between layered Montmorillonite sheets and the work of adhesion between radionuclide and charged Montmorillonite. The clay model used here is a Wyoming-type Montmorillonite with 0.75e negative charge per unit cell resulting from substitutions in Octahedral and Tetrahedral sheets. The system model was constructed based on CLAYFF force field potential model. To evaluate the thermodynamic work of adhesion, each surface and clay layer regions are converted to a thin film model. One and two species of radionuclide elements (UO2(H2O)5,UO2CO3(H2O)5, and UO2Cl2(H2O)5) were deposited near the clay surface in a pseudo-two-dimensional periodic cell. Analysis shows that the uranyl ion structure is preserved with two axial oxygen atoms detected at 1.8 Å. Radial distribution functions results indicate that average UOw distances are 2.45-2.61 Å, and 2.29-2.40 Å for UOc distance. Average UCl distances are 2.78-3.08 Å, which is relatively larger than that of Uranium atom-Oxygen atom because of electrostatic factors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 261, 15 October 2013, Pages 224-234
نویسندگان
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