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 con sidered. Before the dehydration, the surface is composed only of single and geminal silanols. After this process begins, the surface sites are also vi cinal and empty. Two silanols have a hydrogen bridge linking each other dep ending on the local geometric structure. The simulation shows that the dist ribution of the silanols over the silica surface is random at all thr tempe ratures considered. (C) 2000 Elsevier Science B.V. All rights reserved.