Raw data for: Chemistry and Mass Density of Aluminum Hydroxide Gel in Eco- Cements by Ptychographic X‑ray Computed Tomography doi: http://dx.doi.org/10.1021/acs.jpcc.6b10048 Eco-cements are a desirable alternative to ordinary Portland cements because of their lower CO2 footprints. Ye'elimite-based eco-cements are attracting a lot of interest but most of them exhibit relatively poor mechanical properties. Understanding the reasons for the low performances requires the characterization of features such as mass density of the hydrated mineralogical phases, including the amorphous gel, on the sub-micrometer scale which is very challenging. Here we use ptychographic X-ray computed tomography to provide 3D mass density and attenuation coefficient distributions of eco-cement pastes with an isotropic resolution close to 100 nm allowing to distinguish between mineralogical phases with very similar contrast. In combination with laboratory techniques such as the Rietveld method, 27Al MAS-NMR and electron microscopies, we report compositions and densities of key components. The ettringite and gel volume distributions have been mapped out in the segmented tomograms. Moreover, we discriminate between an aluminum hydroxide gel and calcium aluminum monosulfate, which have close electron density values. Specifically, the composition and mass density of two aluminum hydroxide gels have been determined: (CaO)0.04Al(OH)3·2.3H2O with 1.48(3) g∙cm-3 and (CaO)0.12Al(OH)3 with 2.05(3) g∙cm-3, which was a long standing challenge.

Funding Sources This work has been supported by MINECO through BIA2014-57658-C2-1-R and BIA2014-57658-C2-2-R, which is co-funded by FEDER, research grants. We thank SLS for providing beamtime at the cSAXS beamline. We also thank the Swiss National Science Foundation SNF for the support to the work of J. C. da Silva (Grant No. 137772). Instrumentation development was supported by SNF (R'EQUIP, No. 145056,"OMNY") and the Competence Centre for Materials Science and Technology (CCMX) of the ETH-Board, Switzerland. In addition, the authors would like to thank Dr. Manuel Guizar-Sicairos for his valuable assistance with the ptychography and PXCT data analysis.