Oxygen isotope exchange kinetics between H2O and H4SiO4 from ab initio calculations

The mechanism of borosilicate glass corrosion revisited

“…The change in reactivity of the precipitated silica, expressed primarily in the shapes of the 18 An explanation for the decrease in reactivity is provided by ab-initio calculations, demonstrating that oxygen isotope exchange between monomeric silica and water equilibrates within a second at 25°C (Felipe et al, 2004). The same likely applies to O-O exchange between water molecules and surface silanol groups of silica particles (Eq.…”

Reaction pathways for quartz dissolution determined by statistical and graphical analysis of macroscopic experimental data

“…Certain proposed mechanisms for quartz dissolution have received support from quantum mechanical simulations Lasaga, 1994, 1996;Pelmenschikov et al, 2000Pelmenschikov et al, , 2001Felipe et al, 2004;Criscenti et al, 2006;Sahai and Rosso, 2006) (Fig. 1).…”

Calculating the partitioning of the isotopes of Mo between oxidic and sulfidic species in aqueous solution

“…This question has been addressed for various small molecules by Ayala and Schlegel (1998)and by East and Radom (1997), who presented absolute entropies for small molecules with corrections for those modes best described as hindered internal rotations. Felipe et al (2004) made approximate corrections for such effects in their studies on the rates of O isotope exchange by simply setting the vibrational entropy change between reactants or products and the transition states equal to zero. For most of the molecules studied herein, and particularly for MoO 4…”