Identification of montmorillonite particle edge orientations by atomic-force microscopy

Sergey Kraevsky (1, 2, 3, 4) , Christophe Tournassat (2, 5, 6, 7) , Marylène Vayer (8) , Fabienne Warmont (8) , Sylvain Grangeon (2) , Brice F. Ngouana Wakou (1) , Andrey G. Kalinichev (1)

1 SUBATECH - Laboratoire de physique subatomique et des technologies associées
2 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
3 ITEP - Institute of Theoretical and Experimental Physics [Moscow]
4 Federal Research and Clinical Center of Physical-Chemical Medicine
5 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
6 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
7 Biogéosystèmes Continentaux - UMR7327
8 ICMN - Interfaces, Confinement, Matériaux et Nanostructures

Statistical information on the edge surface area and edge crystallographic orientation of clay nanoparticle surfaces is essential for proper accounting of the protonation-deprotonation reactions as a part of mechanistic surface complexation models. A combination of atomic-force microscopy (AFM) measurements and molecular dynamics computer simulations made it possible to quantify the relative contributions of the most frequently occurring montmorillonite edge surfaces to the total edge surface area. Edge surfaces normal to the [110] and [010] crystallographic directions are found to be the most abundant (~60% and ~20%, respectively), in agreement with previous estimations.

Keywords: Clay nanoparticles; Montmorillonite; Edges ratio; AFM; MD simulations

Domains: Sciences of the Universe [physics]; Continental interfaces, environment

Sergey Kraevsky, Christophe Tournassat, Marylène Vayer, Fabienne Warmont, Sylvain Grangeon, et al.. Identification of montmorillonite particle edge orientations by atomic-force microscopy. Applied Clay Science, 2020, 186, 105442 (8 p.). ⟨10.1016/j.clay.2020.105442⟩. ⟨insu-02476314⟩