A series of synthetic natrolites with different non-framework cations (Li-NAT, Na-NAT, K-NAT, Rb-NAT, Cs-NAT, Ca-NAT, Sr-NAT and Pb-NAT) are investigated by high temperature oxide melt solution calorimetry. The formation enthalpy from the component oxides (ΔHf,ox) becomes less exothermic with increasing ionic potential (Z/r) of the cations. The dehydration behavior of NATs is examined using TG-DSC. The strength of water binding decreases with increasing cation size. Similar to the trend seen in anhydrous zeolites, a linear dependence of ΔHf,ox on Al/(Al + Si) ratio for hydrous zeolites is established.
Bibliographical noteFunding Information:
Synthesis work was jointly supported by The Nuclear R&D program and The Global Research Laboratory program of the Korean Research Foundation. Calorimetry was supported by the U.S. Department of Energy, Grant 97ER14749. We thank Tae-Jin Park, Kristina Lilova and Ao Ji for discussions.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials