Mass and momentum interface equilibrium by molecular modeling. Simulating AFM adhesion between (120) gypsum faces in a saturated solution and consequences on gypsum cohesion

P. Jouanna (1) , L. Pedesseau , G. Pepe (2) , Dave Mainprice (1)

1 Géosciences Montpellier
2 GCOMM - Groupe de chimie organique et matériaux moléculaires

Properties of composite materials depend on interatomic phenomena occurring between binder crystals. Experimental information of Atomic Force Microscopy (A.F.M.) is of prime importance; however understanding is helped by molecular modeling. As underlined in Section 1, the present study is able to simulate crystal interfaces in presence of a solution within apertures less than 1 Nanometer at a full atomic scale. Section 2 presents the case study of a gypsum solution between (120) gypsum faces, with related boundary conditions and atomic interactions. Section 3 deals with the mass equilibrium of the solution within interfaces <5 angstrom, using the original Semi Analytical Stochastic Perturbations (SASP) approach. This information becomes in Section 4 the key for explaining the peak of adhesion obtained in A.F.M. around an aperture of 3 A and gives enlightenments on gypsum cohesion. In conclusion, this illustration shows the potentialities of full atomic modeling which could not be attained by any numerical approach at a mesoscopic scale.

Mots clés: microstructure; bond strength; micromechanics; sulfate; modeling

Domaines: Matériaux

P. Jouanna, L. Pedesseau, G. Pepe, Dave Mainprice. Mass and momentum interface equilibrium by molecular modeling. Simulating AFM adhesion between (120) gypsum faces in a saturated solution and consequences on gypsum cohesion. Cement and Concrete Research, 2008, 38 (3), pp.290-299. ⟨10.1016/j.cemconres.2007.09.022⟩. ⟨hal-00411868⟩