Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements
The analysis of atomic ordering in a nanocrystalline phase with small particle sizes, below 5 nm, is intrinsically complicated because of the lack of long-range order. Furthermore, the presence of additional crystalline phase(s) may exacerbate the problem, as is the case in cement pastes. Here, we u...
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| Format: | Article |
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MDPI AG
2017-10-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/7/10/317 |
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| author | Ana Cuesta Jesus D. Zea-Garcia Diana Londono-Zuluaga Angeles G. De la Torre Isabel Santacruz Oriol Vallcorba Miguel A.G. Aranda |
| author_facet | Ana Cuesta Jesus D. Zea-Garcia Diana Londono-Zuluaga Angeles G. De la Torre Isabel Santacruz Oriol Vallcorba Miguel A.G. Aranda |
| author_sort | Ana Cuesta |
| collection | DOAJ |
| description | The analysis of atomic ordering in a nanocrystalline phase with small particle sizes, below 5 nm, is intrinsically complicated because of the lack of long-range order. Furthermore, the presence of additional crystalline phase(s) may exacerbate the problem, as is the case in cement pastes. Here, we use the synchrotron pair distribution function (PDF) chiefly to characterize the local atomic order of the nanocrystalline phases, gels, in cement pastes. We have used a multi r-range analysis approach, where the ~4–7 nm r-range allows determining the crystalline phase contents; the ~1–2.5 nm r-range is used to characterize the atomic ordering in the nanocrystalline component; and the ~0.2–1.0 nm r-range gives insights about additional amorphous components. Specifically, we have prepared four alite pastes with variable water contents, and the analyses showed that a defective tobermorite, Ca11Si9O28(OH)2.8.5H2O, gave the best fit. Furthermore, the PDF analyses suggest that the calcium silicate hydrate gel is composed of this tobermorite and amorphous calcium hydroxide. Finally, this approach has been used to study alternative cements. The hydration of monocalcium aluminate and ye’elimite pastes yield aluminum hydroxide gels. PDF analyses show that these gels are constituted of nanocrystalline gibbsite, and the particle size can be as small as 2.5 nm. |
| first_indexed | 2024-04-13T07:50:39Z |
| format | Article |
| id | doaj.art-b9574f84787a4dd383fbddc6cbc24908 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-13T07:50:39Z |
| publishDate | 2017-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-b9574f84787a4dd383fbddc6cbc249082022-12-22T02:55:32ZengMDPI AGCrystals2073-43522017-10-0171031710.3390/cryst7100317cryst7100317Synchrotron Radiation Pair Distribution Function Analysis of Gels in CementsAna Cuesta0Jesus D. Zea-Garcia1Diana Londono-Zuluaga2Angeles G. De la Torre3Isabel Santacruz4Oriol Vallcorba5Miguel A.G. Aranda6ALBA Synchrotron radiation facility, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, SpainDepartamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga, SpainDepartamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga, SpainDepartamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga, SpainDepartamento de Química Inorgánica, Cristalografía y Mineralogía, Universidad de Málaga, 29071 Málaga, SpainALBA Synchrotron radiation facility, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, SpainALBA Synchrotron radiation facility, Carrer de la Llum 2-26, 08290 Cerdanyola del Vallès, SpainThe analysis of atomic ordering in a nanocrystalline phase with small particle sizes, below 5 nm, is intrinsically complicated because of the lack of long-range order. Furthermore, the presence of additional crystalline phase(s) may exacerbate the problem, as is the case in cement pastes. Here, we use the synchrotron pair distribution function (PDF) chiefly to characterize the local atomic order of the nanocrystalline phases, gels, in cement pastes. We have used a multi r-range analysis approach, where the ~4–7 nm r-range allows determining the crystalline phase contents; the ~1–2.5 nm r-range is used to characterize the atomic ordering in the nanocrystalline component; and the ~0.2–1.0 nm r-range gives insights about additional amorphous components. Specifically, we have prepared four alite pastes with variable water contents, and the analyses showed that a defective tobermorite, Ca11Si9O28(OH)2.8.5H2O, gave the best fit. Furthermore, the PDF analyses suggest that the calcium silicate hydrate gel is composed of this tobermorite and amorphous calcium hydroxide. Finally, this approach has been used to study alternative cements. The hydration of monocalcium aluminate and ye’elimite pastes yield aluminum hydroxide gels. PDF analyses show that these gels are constituted of nanocrystalline gibbsite, and the particle size can be as small as 2.5 nm.https://www.mdpi.com/2073-4352/7/10/317Portland cementcementitious materialsC-S-H gelamorphous phasestotal scattering |
| spellingShingle | Ana Cuesta Jesus D. Zea-Garcia Diana Londono-Zuluaga Angeles G. De la Torre Isabel Santacruz Oriol Vallcorba Miguel A.G. Aranda Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements Crystals Portland cement cementitious materials C-S-H gel amorphous phases total scattering |
| title | Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements |
| title_full | Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements |
| title_fullStr | Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements |
| title_full_unstemmed | Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements |
| title_short | Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements |
| title_sort | synchrotron radiation pair distribution function analysis of gels in cements |
| topic | Portland cement cementitious materials C-S-H gel amorphous phases total scattering |
| url | https://www.mdpi.com/2073-4352/7/10/317 |
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