The distribution of silanols on the amorphous silica surface: a Monte Carlo simulation

A study of the heterogeneity of surface silanols over partially dehydrated amorphous silica has been carried out by a Monte Carlo simulation. For this purpose the presence of (100) and (111) face patches on the surface is considered. Before the dehydration, the surface is composed only of single and geminal silanols. After this process begins, the surface sites are also vicinal and empty. Two silanols have a hydrogen bridge linking each other depending on the local geometric structure. The simulation shows that the distribution of the silanols over the silica surface is random at all thr temperatures considered. (C) 2000 Elsevier Science B.V. All rights reserved.