Aqueous dissolution of sodium aluminosilicate geopolymers derived from metakaolin

► In dilute solutions, Na, Al and Si releases were not sensitive to pH in range 4-10. ► On heating from 18 to 90 °C in DIW, Na dissolution rate increased by a factor of ∼4. ► Elemental extractions in DIW at 18 °C increased linearly with time over 1-7 days. ► Na release kinetics in DIW followed a pseudo-second-order kinetic model. ► Contact with KCl, KHCO3 and phthalate buffers (pH6 & 10) resulted in Na+ ↔ K+ exchange.