Study of the effect of hydration on the tensile strength of a silica nanotube

Abstract

Molecular dynamics simulations using quantum mechanical potentials have been performed to study the interaction of water with silica. The water–water and water–silica interactions were determined at the ab initio coupled cluster and MBPT(2) levels of theory and the resulting forces and reaction mechanisms encoded into a transfer Hamiltonian. Using forces from the rapid evaluation of the transfer Hamiltonian, two prototypical systems, consisting of an (SiO2)10 ring and a 108 atom silica nanorod, were fractured in the presence of water. It was found that inclusion of water caused a reduction in tensile strength of both systems and that the water dimer, as suggested by ab initio calculations, is the most effective mediator of Si–O bond rupture.