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Wang HW, Daemen LL, Cheshire MC, Kidder MK, Stack AG, Allard LF, Neuefeind J, Olds D, Liu J, Page K. Synthesis and structure of synthetically pure and deuterated amorphous (basic) calcium carbonates. Chem Commun (Camb) 2017; 53:2942-2945. [DOI: 10.1039/c6cc08848a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first neutron PDF data on deuterated A(B)CC, shedding new light on H(D)-bearing species in controlling polyamorphism and crystallization processes.
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Affiliation(s)
- Hsiu-Wen Wang
- Shull Wollan Center
- The University of Tennessee/Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Luke L. Daemen
- Spallation Neutron Source
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | | | | | - Andrew G. Stack
- Chemical Sciences Division
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Lawrence F. Allard
- Materials Science and Technology Division
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Jörg Neuefeind
- Spallation Neutron Source
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Daniel Olds
- Spallation Neutron Source
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Jue Liu
- Spallation Neutron Source
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Katharine Page
- Spallation Neutron Source
- Oak Ridge National Laboratory
- Oak Ridge
- USA
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3
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Krishnan NMA, Wang B, Falzone G, Le Pape Y, Neithalath N, Pilon L, Bauchy M, Sant G. Confined Water in Layered Silicates: The Origin of Anomalous Thermal Expansion Behavior in Calcium-Silicate-Hydrates. ACS APPLIED MATERIALS & INTERFACES 2016; 8:35621-35627. [PMID: 27977137 DOI: 10.1021/acsami.6b11587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Water, under conditions of nanoscale confinement, exhibits anomalous dynamics, and enhanced thermal deformations, which may be further enhanced when such water is in contact with hydrophilic surfaces. Such heightened thermal deformations of water could control the volume stability of hydrated materials containing nanoconfined structural water. Understanding and predicting the thermal deformation coefficient (TDC, often referred to as the CTE, coefficient of thermal expansion), which represents volume changes induced in materials under conditions of changing temperature, is of critical importance for hydrated solids including: hydrogels, biological tissues, and calcium silicate hydrates, as changes in their volume can result in stress development, and cracking. By pioneering atomistic simulations, we examine the physical origin of thermal expansion in calcium-silicate-hydrates (C-S-H), the binding agent in concrete that is formed by the reaction of cement with water. We report that the TDC of C-S-H shows a sudden increase when the CaO/SiO2 (molar ratio; abbreviated as Ca/Si) exceeds 1.5. This anomalous behavior arises from a notable increase in the confinement of water contained in the C-S-H's nanostructure. We identify that confinement is dictated by the topology of the C-S-H's atomic network. Taken together, the results suggest that thermal deformations of hydrated silicates can be altered by inducing compositional changes, which in turn alter the atomic topology and the resultant volume stability of the solids.
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Affiliation(s)
- N M Anoop Krishnan
- Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
- Laboratory for the Physics of Amorphous and Inorganic Solids (PARISlab), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Bu Wang
- Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
- Laboratory for the Physics of Amorphous and Inorganic Solids (PARISlab), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Gabriel Falzone
- Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Yann Le Pape
- Oak Ridge National Laboratory , P.O. Box 2008, Oak Ridge, Tennessee 37831, United States
| | - Narayanan Neithalath
- School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85281, United States
| | - Laurent Pilon
- Department of Mechanical and Aerospace Engineering, University of California , Los Angeles, California 90095, United States
| | - Mathieu Bauchy
- Laboratory for the Physics of Amorphous and Inorganic Solids (PARISlab), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
| | - Gaurav Sant
- Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California , Los Angeles, California 90095, United States
- California Nanosystems Institute (CNSI), University of California , Los Angeles, California 90095, United States
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Hajilar S, Shafei B. Assessment of structural, thermal, and mechanical properties of portlandite through molecular dynamics simulations. J SOLID STATE CHEM 2016. [DOI: 10.1016/j.jssc.2016.09.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Guthrie M. Future directions in high-pressure neutron diffraction. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:153201. [PMID: 25789450 DOI: 10.1088/0953-8984/27/15/153201] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The ability to manipulate structure and properties using pressure has been well known for many centuries. Diffraction provides the unique ability to observe these structural changes in fine detail on lengthscales spanning atomic to nanometre dimensions. Amongst the broad suite of diffraction tools available today, neutrons provide unique capabilities of fundamental importance. However, to date, the growth of neutron diffraction under extremes of pressure has been limited by the weakness of available sources. In recent years, substantial government investments have led to the construction of a new generation of neutron sources while existing facilities have been revitalized by upgrades. The timely convergence of these bright facilities with new pressure-cell technologies suggests that the field of high-pressure (HP) neutron science is on the cusp of substantial growth. Here, the history of HP neutron research is examined with the hope of gleaning an accurate prediction of where some of these revolutionary capabilities will lead in the near future. In particular, a dramatic expansion of current pressure-temperature range is likely, with corresponding increased scope for extreme-conditions science with neutron diffraction. This increase in coverage will be matched with improvements in data quality. Furthermore, we can also expect broad new capabilities beyond diffraction, including in neutron imaging, small angle scattering and inelastic spectroscopy.
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Affiliation(s)
- M Guthrie
- European Spallation Source, ESS AB, SE-22100 Lund Sweden
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Iizuka R, Komatsu K, Kagi H, Nagai T, Sano-Furukawa A, Hattori T, Gotou H, Yagi T. Phase transitions and hydrogen bonding in deuterated calcium hydroxide: High-pressure and high-temperature neutron diffraction measurements. J SOLID STATE CHEM 2014. [DOI: 10.1016/j.jssc.2014.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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