Synthesis, structural characterization, and thermodynamic properties of 11Å Al‐tobermorite

In the present paper, the structure as well as the solubility and thermodynamic data of synthesized Al‐tobermorite is discussed. 29Si NMR and XRD prove the successful synthesis of an Al‐tobermorite with a ratio of Al/(Al + Si) = 0.1. The aluminum is incorporated in the branching (Q3) sites of the silicate chains. Solubility of the synthesized Al‐tobermorite can be calculated from the measured ionic concentrations from storage in aqueous solution, which show little variation over time. The tobermorite remains stable in aqueous solution. Consequently, an equilibrium between aqueous solution and the synthesized Al‐tobermorite can be assumed. On the basis of the experiments, thermodynamic data for Al‐tobermorite can be estimated and presented in the present paper.