RT Journal Article
T1 Chemistry and Mass Density of Aluminum Hydroxide Gel in Eco-Cements by Ptychographic X-ray Computed Tomography
A1 Cuesta-García, Ana María
A1 Gómez-de-la-Torre, María de los  Ángeles
A1 Santacruz-Cruz, María Isabel
A1 Trtik, Pavel
A1 Da Silva, Julio C.
A1 Díaz, Ana
A1 Holler, Mirko
A1 García-Aranda, Miguel Ángel
K1 Cemento
AB Eco-cements are a desirable alternative to ordinary Portlandcements because of their lower CO2 footprints. Some ye’elimite-based ecocementsare attracting a lot of interest. Understanding the reasons for themechanical performances requires the characterization of features such as massdensity of the hydrated component phases, including the amorphous gel, onthe submicrometer scale, which is challenging. Here we use ptychographic Xraycomputed tomography to provide 3D mass density and attenuationcoefficient distributions of eco-cement pastes with an isotropic resolution closeto 100 nm allowing to distinguish between component phases with verysimilar contrast. In combination with laboratory techniques such as theRietveld method, 27Al MAS NMR, and electron microscopies, we report compositions and densities of key components. Theettringite and gel volume distributions have been mapped out in the segmented tomograms. Moreover, we discriminate betweenan aluminum hydroxide gel and calcium aluminum monosulfate, which have close electron density values. Specifically, thecomposition and mass density of two aluminum hydroxide gel agglomerates have been determined: (CaO)0.04Al(OH)3·2.3H2Owith 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.
PB ACS
SN 1932-7455
YR 2017
FD 2017
LK http://hdl.handle.net/10630/13629
UL http://hdl.handle.net/10630/13629
LA eng
NO J. Phys. Chem. C 2017, 121, 3044−3054
NO This work has been supported by MINECO throughBIA2014−57658-C2-1-R and BIA2014-57658-C2-2-R, whichis cofunded by FEDER, research grants. We thank SLS forproviding beamtime at the cSAXS beamline. We also thank theSwiss National Science Foundation SNF for the support to thework of J.C.d.S. (Grant 137772). Instrumentation developmentwas supported by SNF (R’EQUIP, No. 145056,“OMNY”) andthe Competence Centre for Materials Science and Technology(CCMX) of the ETH-Board, Switzerland. In addition, theauthors would like to thank Dr. Manuel Guizar-Sicairos for hisvaluable assistance with the ptychography and PXCT dataanalysis.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 3 mar 2026