Published online by Cambridge University Press: 26 February 2011
Zeta potentials of SRL-131-29.8% TOS simulated nuclear waste glasses leached in D.I. water, Al, Ca, Mg, and Zn chloride solutions at 90°C were measured as a function of leaching time. For short term leaching, the adsorption of Ca, Mg, Zn and Al reverses the glass surface potential from negative to positive. Colloids were found to be stable in D.I. water and AICl3 solutions after leaching, presumably due to the electrostatic repulsion between the glass surface and similarly charged particles. Colloids were not found in Mg, Zn or Ca chloride solutions after leaching; instead, a relatively thick metasilicate surface layer was formed on glass surfaces leached in these solutions. The concentration of Si in solution is reduced by the formation of these surface layers.