Quantitative X-ray pair distribution function analysis of nanocrystalline calcium silicate hydrates: a contribution to the understanding of cement chemistry
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- 作者：Sylvain Grangeon ; Alejandro Fernandez-Martinez ; Alain Baronnet ; Nicolas Marty ; Agnieszka Poulain ; Erik Elkaï ; m ; Cé ; dric Roosz ; Sté ; phane Gaboreau ; Pierre Henocq and Francis Claret
- 关键词：C&ndash ; S&ndash ; H ; calcium silicate hydrates ; pair distribution function ; transmission electron microscopy
- 刊名：Journal of Applied Crystallography
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：50
- 期：1
- 页码：14-21
- 全文大小：1381K
- ISSN：1600-5767
文摘
The structural evolution of nanocrystalline calcium silicate hydrate (C–S–H) as a function of its calcium to silicon (Ca/Si) ratio has been probed using qualitative and quantitative X-ray atomic pair distribution function analysis of synchrotron X-ray scattering data. Whatever the Ca/Si ratio, the C–S–H structure is similar to that of tobermorite. When the Ca/Si ratio increases from ∼0.6 to ∼1.2, Si wollastonite-like chains progressively depolymerize through preferential omission of Si bridging tetrahedra. When the Ca/Si ratio approaches ∼1.5, nanosheets of portlandite are detected in samples aged for 1 d, while microcrystalline portlandite is detected in samples aged for 1 year. High-resolution transmission electron microscopy imaging shows that the tobermorite-like structure is maintained to Ca/Si > 3.