Numerical modelling of glass dissolution: gel layer morphology

Numerical simulations of glass dissolution are presented. The glass is mode lized as a random binary mixture composed of two species representing silic a and soluble oxides, such as boron and alkali oxides. The soluble species are dissolved immediately when they are in contact with the solution. For t he species which represents silica, one introduces dissolution and condensa tion probabilities. It is shown that the morphology and the thickness of th e surface hydration layer (the gel) are highly dependent on the dissolution model, especially on the parameter which controls the surface tension. Sim ulations with different glass surface area to solution volume ratio (SIV) s how that this experimental parameter as important effects on both the shrin kage and the gel layer thickness. (C) 2001 Elsevier Science B.V. All rights reserved.