MODELING OF INTERCALATED CLAY-MINERALS

Molecular mechanics simulations in Cerius(2) modelling environment hav e been used to investigate the structure of montmorillonites, intercal ated with aluminium complex cations. Two different intercalating speci es have been investigated: 1. Keggin cation (ideal and hydrolyzed) and 2. gibbsite-like polymers, arranged in two layers in the interlayer o f montmorillonites. The results of molecular simulations showed that t he position, orientation, and concentration of Keggin cations in the i nterlayer space depends on the degree of hydrolysis. The average value s of basal spacings for different degree of hydrolysis are within the range of 19.51--20.05 10(-10) m. in the case of gibbsite-like polymers , arranged in two layers in the interlayer of montmorillonites, basal spacing depends on the mutual position of Al-OH polymers. Average basa l spacings for different arrangements of Al(OH)(3) fragments are in th e range of 19.58-20.06 10(-10) m. Molecular simulations also showed th at for both intercalating species no two-dimensional ordering of compl ex cations can occur in the interlayer of montmorillonites.