1
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Li D, Zhu J, Liu Q, Qi Q, Bai Z. Degradation of thermal stability and micromechanical properties of the C-S-H phase induced by ultra-confined water at elevated temperatures. Phys Chem Chem Phys 2023. [PMID: 38037879 DOI: 10.1039/d3cp03804a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Water in the nanometer to micrometer-sized pores of calcium silicate hydrate (C-S-H) is essential for the binding process of cementitious materials. The quantity, location, and physical state of water in C-S-H pores under extreme conditions significantly influence the strength and durability of cementitious materials. The present study employed ReaxFF and molecular dynamics (MD) simulation to evaluate the effects of water ultra-confined in the nanopores on the structure, bonds, dynamics, and tensile mechanism of the C-S-H grains at elevated temperatures. The results indicate that the temperature elevation may interfere with the water molecule's hydrogen-bond network between the C-S-H grains, causing a notable nanometer-scale pore expansion. Simultaneously, the diffusion coefficient of water molecules confined in nanopores gradually increased, and their dynamic characteristics shifted from a glassy nature to free water. Additionally, high temperatures promoted hydrolysis reactions and the breakage of chemical bonds in the C-S-H framework, causing disintegration of the silicate skeleton and a decrease in the mechanical attributes of C-S-H. Moreover, the uniaxial tensile test at high temperatures revealed that the silicate chain groups in the C-S-H substrates underwent thermal curling. In contrast to interlayer-bound water, under the action of tension, water molecules in nanopores are viscous, forming water layers.
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Affiliation(s)
- Dongbo Li
- School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Jing Zhu
- School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Qinlong Liu
- Mechanical Experiment Center, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Qinde Qi
- School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China.
| | - Zhentao Bai
- College of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
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2
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Salha MS, Yada RY, Farrar DH, Chass GA, Tian KV, Bodo E. Aluminium catalysed oligomerisation in cement-forming silicate systems. Phys Chem Chem Phys 2022; 25:455-461. [PMID: 36477563 DOI: 10.1039/d2cp03918d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alumino-silicates form the backbone of structural materials including cements and the concrete they form. However, the nanoscale aspects of the oligomerisation mechanisms elongating the (alumino-)silicate chains is not fully clarified; the role of aluminium in particular. Herein, we explore and contrast the growth of silicate and alumino-silicate oligomers by both neutral and anionic mechanisms, with focus on the influence of Al on oligomer structure and stability. Further, the spontaneity of chain lengthening in the absence and presence of Al of differing coordination (Al-IV, V, VI) was characterised. Result trends showed Al-IV facilitating oligomerisation in neutral conditions, with respect to Si only systems, effectively promoting longer chain formation and stabilisation. The anionic pathway similarly showed Al reducing the overall energetic barriers to oligomerisation. In both conditions, Al's coordinative and structural flexibility, at O-Al-O hinge points in particular, was responsible for the lowering of the energetic expense for oligomerisation. The results and implications resolved herein are informative for chain formation and stability for bulk material properties of alumino-silicate materials such as cements, where the aluminosilicate systems are dominated by short chains of 2-5 units in length.
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Affiliation(s)
- Mohammed S Salha
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Roma, Italy.,Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Rickey Y Yada
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - David H Farrar
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Gregory A Chass
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.,Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,School of Physical and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK.
| | - Kun V Tian
- Faculty of Land and Food Systems, The University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.,Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Department of Chemical Science and Pharmaceutical Technologies, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Roma, Italy.
| | - Enrico Bodo
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Roma, Italy
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3
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A Molecular Description of Hydrogel Forming Polymers for Cement-Based Printing Paste Applications. Gels 2022; 8:gels8090592. [PMID: 36135304 PMCID: PMC9498349 DOI: 10.3390/gels8090592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/17/2022] Open
Abstract
This research endeavors to link the physical and chemical characteristics of select polymer hydrogels to differences in printability when used as printing aids in cement-based printing pastes. A variety of experimental probes including differential scanning calorimetry (DSC), NMR-diffusion ordered spectroscopy (DOSY), quasi-elastic neutron scattering (QENS) using neutron backscattering spectroscopy, and X-ray powder diffraction (XRD), along with molecular dynamic simulations, were used. Conjectures based on objective measures of printability and physical and chemical-molecular characteristics of the polymer gels are emerging that should help target printing aid selection and design, and mix formulation. Molecular simulations were shown to link higher hydrogen bond probability and larger radius of gyration to higher viscosity gels. Furthermore, the higher viscosity gels also produced higher elastic properties, as measured by neutron backscattering spectroscopy.
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4
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Chen Y, Chen M, Tong X, Wang S, Kang X. Molecular insights into the interactions between chloride liquids and C−S−H nanopore surfaces under electric field-induced transport. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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5
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Zhang R, Troya D, Madsen LA. Prolonged Association between Water Molecules under Hydrophobic Nanoconfinement. J Phys Chem B 2021; 125:13767-13777. [PMID: 34898212 DOI: 10.1021/acs.jpcb.1c06810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present an investigation of the dynamics of water confined among rigid carbon rods and between parallel graphene sheets with molecular dynamics simulations. Diffusion coefficients, activation energy of diffusion, and residence-time correlation functions as a function of confinement geometry reveal a retardation of water dynamics under hydrophobic confinement compared to bulk water. In fact, water under various confinements possesses longer associations with its neighbors and exhibits diffusion dynamics characteristic of a lower temperature. Analysis of the residence-time correlation functions reveals long and short residence times, which we relate to the diffusion coefficient and activation energy of diffusion, respectively. Additional investigations reveal how the level of confining surface hydrophobicity affects water dynamics, further broadening our understanding of water diffusion inside diverse media. Overall, this study sheds light on the physical origin of retarded water dynamics under hydrophobic confinement and the close relationship between residence times and diffusion behavior.
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Affiliation(s)
- Rui Zhang
- Department of Chemistry and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Diego Troya
- Department of Chemistry and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Louis A Madsen
- Department of Chemistry and Macromolecules Innovation Institute, Virginia Tech, Blacksburg, Virginia 24061, United States
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6
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Verdolotti L, Santillo C, Rollo G, Romanelli G, Lavorgna M, Liguori B, Lama GC, Preziosi E, Senesi R, Andreani C, di Prisco M. MWCNT/rGO/natural rubber latex dispersions for innovative, piezo-resistive and cement-based composite sensors. Sci Rep 2021; 11:18975. [PMID: 34556805 PMCID: PMC8460753 DOI: 10.1038/s41598-021-98596-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 08/27/2021] [Indexed: 02/08/2023] Open
Abstract
The present study is focused on the development and characterization of innovative cementitious-based composite sensors. In particular, multifunctional cement mortars with enhanced piezoresistive properties are realized by exploiting the concept of confinement of Multiwall Carbon Nanotubes (MWCNTs) and reduced Graphene Oxide (rGO) in a three-dimensional percolated network through the use of a natural-rubber latex aqueous dispersion. The manufactured cement-based composites were characterized by means of Inelastic Neutron Scattering to assess the hydration reactions and the interactions between natural rubber and the hydrated-cement phases and by Scanning Electron Microscopy and X-Ray diffraction to evaluate the morphological and mineralogical structure, respectively. Piezo-resistive properties to assess electro-mechanical behavior in strain condition are also measured. The results show that the presence of natural rubber latex allows to obtain a three-dimensional rGO/MWCNTs segregate structure which catalyzes the formation of hydrated phases of the cement and increases the piezo-resistive sensitivity of mortar composites, representing a reliable approach in developing innovative mortar-based piezoresistive strain sensors.
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Affiliation(s)
- L. Verdolotti
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy ,grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, Via Previati 1/C, 23900 Lecco, Milan, Italy
| | - C. Santillo
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy
| | - G. Rollo
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy
| | - G. Romanelli
- grid.14467.30Rutherford Appleton Laboratory, ISIS Facility, Chilton, Didcot, Oxfordshire, OX11OQX UK
| | - M. Lavorgna
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy ,grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, Via Previati 1/C, 23900 Lecco, Milan, Italy
| | - B. Liguori
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy ,grid.4691.a0000 0001 0790 385XDepartment of Chemical, Materials and Production Engineering, University of Naples Federico II, P.le Tecchio, 1, 80138 Naples, Italy
| | - G. C. Lama
- grid.5326.20000 0001 1940 4177Institute of Polymers, Composite and Biomaterials, National Research Council, , P.Le Enrico Fermi, 1, 80055 Portici, Naples, Italy
| | - E. Preziosi
- grid.6530.00000 0001 2300 0941Dipartimento di Fisica and NAST Centre, Università degli Studi di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - R. Senesi
- grid.6530.00000 0001 2300 0941Dipartimento di Fisica and NAST Centre, Università degli Studi di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - C. Andreani
- grid.6530.00000 0001 2300 0941Dipartimento di Fisica and NAST Centre, Università degli Studi di Roma “Tor Vergata”, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - M. di Prisco
- grid.4643.50000 0004 1937 0327Department of Civil and Environmental Engineering, Politecnico di Milano, P.za Leonardo da Vinci, 32, 20133 Milan, Italy
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7
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Goyal A, Palaia I, Ioannidou K, Ulm FJ, van Damme H, Pellenq RJM, Trizac E, Del Gado E. The physics of cement cohesion. SCIENCE ADVANCES 2021; 7:7/32/eabg5882. [PMID: 34348896 PMCID: PMC8336951 DOI: 10.1126/sciadv.abg5882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/17/2021] [Indexed: 06/13/2023]
Abstract
Cement is the most produced material in the world. A major player in greenhouse gas emissions, it is the main binding agent in concrete, providing a cohesive strength that rapidly increases during setting. Understanding how such cohesion emerges is a major obstacle to advances in cement science and technology. Here, we combine computational statistical mechanics and theory to demonstrate how cement cohesion arises from the organization of interlocked ions and water, progressively confined in nanoslits between charged surfaces of calcium-silicate-hydrates. Because of the water/ions interlocking, dielectric screening is drastically reduced and ionic correlations are proven notably stronger than previously thought, dictating the evolution of nanoscale interactions during cement hydration. By developing a quantitative analytical prediction of cement cohesion based on Coulombic forces, we reconcile a fundamental understanding of cement hydration with the fully atomistic description of the solid cement paste and open new paths for scientific design of construction materials.
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Affiliation(s)
- Abhay Goyal
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA.
| | - Ivan Palaia
- Université Paris-Saclay, CNRS, LPTMS, 91405 Orsay, France
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Katerina Ioannidou
- Laboratoire de Mécanique et Génie Civil, CNRS, Université de Montpellier, 34090 Montpellier, France
- Massachusetts Institute of Technology/CNRS/Aix-Marseille University Joint Laboratory, Cambridge, MA 02139, USA
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Franz-Josef Ulm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Henri van Damme
- École Supérieure de Physique et Chimie Industrielle de la Ville de Paris, 10 rue Vauquelin, 75005 Paris, France
| | - Roland J-M Pellenq
- Massachusetts Institute of Technology/CNRS/Aix-Marseille University Joint Laboratory, Cambridge, MA 02139, USA
- Department of Physics, Georgetown University, Washington, DC 20057, USA
| | | | - Emanuela Del Gado
- Department of Physics, Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA.
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8
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Structure, Fractality, Mechanics and Durability of Calcium Silicate Hydrates. FRACTAL AND FRACTIONAL 2021. [DOI: 10.3390/fractalfract5020047] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cement-based materials are widely utilized in infrastructure. The main product of hydrated products of cement-based materials is calcium silicate hydrate (C-S-H) gels that are considered as the binding phase of cement paste. C-S-H gels in Portland cement paste account for 60–70% of hydrated products by volume, which has profound influence on the mechanical properties and durability of cement-based materials. The preparation method of C-S-H gels has been well documented, but the quality of the prepared C-S-H affects experimental results; therefore, this review studies the preparation method of C-S-H under different conditions and materials. The progress related to C-S-H microstructure is explored from the theoretical and computational point of view. The fractality of C-S-H is discussed. An evaluation of the mechanical properties of C-S-H has also been included in this review. Finally, there is a discussion of the durability of C-S-H, with special reference to the carbonization and chloride/sulfate attacks.
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9
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Kupwade-Patil K, Boul PJ, Rasner DK, Lapidus SH, Leao JB, Johnson KD, Thaemlitz CJ, Büyüköztürk O. In situ investigation of phosphonate retarder interaction in oil well cements at elevated temperature and pressure conditions. JOURNAL OF THE AMERICAN CERAMIC SOCIETY. AMERICAN CERAMIC SOCIETY 2020; 103:10.1111/jace.17373. [PMID: 37533536 PMCID: PMC10395400 DOI: 10.1111/jace.17373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 07/08/2020] [Indexed: 08/04/2023]
Abstract
The effect of a high-performance retarding additive in oil well cements was investigated under elevated temperature (165°C) and pressure (1000 psi) conditions via in situ synchrotron-based X-ray diffraction (XRD) and quasielastic neutron scattering (QENS) techniques. Under these temperature and pressure conditions, crystalline calcium silicate hydrates (C-S-H) are formed through the cement hydration process. From in situ XRD experiments, the retardation effect was observed by a change in the rate of the appearance of 11 Å tobermorites as well as a change in the rate of the α-C2SH generation and depletion. QENS analysis revealed that the retardation effect was related to the non-conversion of free water to chemical and constrained water components. A high presence of free water components was attributed to a decrease in 11 Å tobermorites along with slower consumption of the quartz and portlandite phases. Furthermore, QENS results infer that the water molecules experienced confinement in the restricted pore spaces. The retarder inhibited this initial water confinement by slowing the bulk diffusion of free water in the confined region.
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Affiliation(s)
- Kunal Kupwade-Patil
- Laboratory for Infrastructure Science and Sustainability (LISS), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | | | | | - Saul H. Lapidus
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - Juscelino B. Leao
- NIST Center for Neutron Research (NCNR), National Institute of Standards and Technology, Gaithersburg, MD, USA
| | | | | | - Oral Büyüköztürk
- Laboratory for Infrastructure Science and Sustainability (LISS), Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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10
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Cho BH, Chung W, Nam BH. Molecular Dynamics Simulation of Calcium-Silicate-Hydrate for Nano-Engineered Cement Composites-A Review. NANOMATERIALS 2020; 10:nano10112158. [PMID: 33138107 PMCID: PMC7693929 DOI: 10.3390/nano10112158] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/19/2020] [Accepted: 10/20/2020] [Indexed: 01/01/2023]
Abstract
With the continuous research efforts, sophisticated predictive molecular dynamics (MD) models for C-S-H have been developed, and the application of MD simulation has been expanded from fundamental understanding of C-S-H to nano-engineered cement composites. This paper comprehensively reviewed the current state of MD simulation on calcium-silicate-hydrate (C-S-H) and its diverse applications to nano-engineered cement composites, including carbon-based nanomaterials (i.e., carbon nanotube, graphene, graphene oxide), reinforced cement, cement–polymer nanocomposites (with an application on 3D printing concrete), and chemical additives for improving environmental resistance. In conclusion, the MD method could not only compute but also visualize the nanoscale behaviors of cement hydrates and other ingredients in the cement matrix; thus, fundamental properties of C-S-H structure and its interaction with nanoparticles can be well understood. As a result, the MD enabled us to identify and evaluate the performance of new advanced nano-engineered cement composites.
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Affiliation(s)
- Byoung Hooi Cho
- Department of Civil, Environmental and Construction Engineering, University of Central Florida, 12800 Pegasus Drive, Suite 211, Orlando, FL 32816, USA
| | - Wonseok Chung
- Department of Civil Engineering, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si 17104, Korea
| | - Boo Hyun Nam
- Department of Civil, Environmental and Construction Engineering, University of Central Florida, 12800 Pegasus Drive, Suite 211, Orlando, FL 32816, USA
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11
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Lyngdoh GA, Kumar R, Krishnan NMA, Das S. Realistic atomic structure of fly ash-based geopolymer gels: Insights from molecular dynamics simulations. J Chem Phys 2019. [DOI: 10.1063/1.5121519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Gideon A. Lyngdoh
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Rajesh Kumar
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - N. M. Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Sumanta Das
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, Rhode Island 02881, USA
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12
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Martins ML, Dinitzen AB, Mamontov E, Rudić S, Pereira JEM, Hartmann-Petersen R, Herwig KW, Bordallo HN. Water dynamics in MCF-7 breast cancer cells: a neutron scattering descriptive study. Sci Rep 2019; 9:8704. [PMID: 31213625 PMCID: PMC6581907 DOI: 10.1038/s41598-019-45056-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 05/29/2019] [Indexed: 01/09/2023] Open
Abstract
Water mobility in cancer cells could be a powerful parameter to predict the progression or remission of tumors. In the present descriptive work, new insight into this concept was achieved by combining neutron scattering and thermal analyses. The results provide the first step to untangle the role played by water dynamics in breast cancer cells (MCF-7) after treatment with a chemotherapy drug. By thermal analyses, the cells were probed as micrometric reservoirs of bulk-like and confined water populations. Under this perspective we showed that the drug clearly alters the properties of the confined water. We have independently validated this idea by accessing the cellular water dynamics using inelastic neutron scattering. Finally, analysis of the quasi-elastic neutron scattering data allows us to hypothesize that, in this particular cell line, diffusion increases in the intracellular water in response to the action of the drug on the nanosecond timescale.
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Affiliation(s)
- Murillo L Martins
- Niels Bohr Institute, University of Copenhagen, DK-2100, Copenhagen, Denmark. .,System and Production Engineering Graduate Program, Pontifical Catholic University of Goias, 74605-010, Goiania, Brazil.
| | | | - Eugene Mamontov
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States
| | - Svemir Rudić
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 OQX, UK
| | - José E M Pereira
- Niels Bohr Institute, University of Copenhagen, DK-2100, Copenhagen, Denmark
| | | | - Kenneth W Herwig
- Neutron Scattering Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States
| | - Heloisa N Bordallo
- Niels Bohr Institute, University of Copenhagen, DK-2100, Copenhagen, Denmark.,European Spallation Source, PO Box 176, SE-221 00, Lund, Sweden
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13
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Gong K, Cheng Y, Daemen LL, White CE. In situ quasi-elastic neutron scattering study on the water dynamics and reaction mechanisms in alkali-activated slags. Phys Chem Chem Phys 2019; 21:10277-10292. [PMID: 31070223 DOI: 10.1039/c9cp00889f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, in situ quasi-elastic neutron scattering (QENS) has been employed to probe the water dynamics and reaction mechanisms occurring during the formation of NaOH- and Na2SiO3-activated slags, an important class of low-CO2 cements, in conjunction with isothermal conduction calorimetry (ICC), Fourier transform infrared spectroscopy (FTIR) analysis and N2 sorption measurements. We show that the single ICC reaction peak in the NaOH-activated slag is accompanied with a transformation of free water to bound water (from QENS analysis), which directly signals formation of a sodium-containing aluminum-substituted calcium-silicate-hydrate (C-(N)-A-S-H) gel, as confirmed by FTIR. In contrast, the Na2SiO3-activated slag sample exhibits two distinct reaction peaks in the ICC data, where the first reaction peak is associated with conversion of constrained water to bound and free water, and the second peak is accompanied by conversion of free water to bound and constrained water (from QENS analysis). The second conversion is attributed to formation of the main reaction product (i.e., C-(N)-A-S-H gel) as confirmed by FTIR and N2 sorption data. Analysis of the QENS, FTIR and N2 sorption data together with thermodynamic information from the literature explicitly shows that the first reaction peak is associated with the formation of an initial gel (similar to C-(N)-A-S-H gel) that is governed by the Na+ ions and silicate species in Na2SiO3 solution and the dissolved Ca/Al species from slag. Hence, this study exemplifies the power of in situ QENS, when combined with laboratory-based characterization techniques, in elucidating the water dynamics and associated chemical mechanisms occurring in complex materials, and has provided important mechanistic insight on the early-age reactions occurring during formation of two alkali-activated slags.
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Affiliation(s)
- Kai Gong
- Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
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14
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Hajilar S, Shafei B. Structure, orientation, and dynamics of water-soluble ions adsorbed to basal surfaces of calcium monosulfoaluminate hydrates. Phys Chem Chem Phys 2018; 20:24681-24694. [PMID: 30187069 DOI: 10.1039/c8cp03872d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Transport of water molecules and chloride ions in nanopores of hydrated cement paste (HCP) is proven to adversely affect the long-term durability of reinforced concrete structures exposed to seawater or deicing salts. The resistance against chloride attack is primarily associated with the chloride binding capacity of the main HCP constituents. Experimental tests revealed that AFm phases of HCP play a central role in binding the chloride ions. However, many aspects of AFm-solution interactions were largely unknown, especially at their interfaces. This was the motivation of the current study, in which the atomistic processes underlying the transport of water-soluble ions are investigated in detail using the classical molecular dynamics (MD) method. To this end, an aqueous layer containing various concentrations of sodium chloride solution is sandwiched between two basal surfaces of calcium monosulfoaluminate hydrate, which is the most abundant phase of AFm. The adsorption mechanisms of water molecules and diffusing ions are then characterized for inner- and outer-sphere distance ranges from the basal surfaces of monosulfoaluminate. It is found that the self-diffusion coefficient of the chloride and sodium ions present in the outer-sphere range are 83% and 47% larger than those residing in the inner-sphere range. With increasing the distance from the solid surface, an increase in the self-diffusion coefficient is captured. This increase in mobility is larger for chloride ions than sodium ions. This can be understood based on the observation that the inner- and outer-sphere complex formation are the governing adsorption mechanisms for the chloride and sodium ions, respectively.
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Affiliation(s)
- Shahin Hajilar
- Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50011, USA.
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15
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Zhang Y, Li T, Hou D, Zhang J, Jiang J. Insights on magnesium and sulfate ions' adsorption on the surface of sodium alumino-silicate hydrate (NASH) gel: a molecular dynamics study. Phys Chem Chem Phys 2018; 20:18297-18310. [PMID: 29966028 DOI: 10.1039/c8cp02469c] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The movement of water and ions in sodium alumino-silicate hydrate gel (NASH) influences the physical and chemical properties of the geopolymer material. In this paper, in order to better understand the structure and dynamics of water and ions in the interfacial region of the NASH gel, molecular dynamics was utilized to model Na2SO4 and MgSO4 solutions (both at 0.44 mol L-1) near the NASH surface. The broken silicate-aluminate surface network, with predominant percentage of randomly connected Q1 and Q2 silicate and aluminate species, provides plenty of non-bridging oxygen sites to accept the H bond from the surface water molecules, contributing toward a strongly adsorbed hydration layer with a thickness of around 5 Å. Consequently, the water molecule in the hydration layer exhibits increased density, increased dipole moment magnitude, orientation preference, and slow diffusivity. In contrast, up to 36.4% of the counter sodium ions, originally caged in the vacancies on the NASH surface, gradually dissociate from the silicate-aluminate skeleton and migrate into the bulk solution, which is consistent with the experimentally observed leaching process of alkali ions in the geopolymer material. In the MgSO4 solution, the magnesium ions-with a smaller ionic radius-penetrate into the silicate-aluminate skeleton vacancy, have 1.8 to 2.5 coordinated solid oxygen atoms, and remain on the NASH surface for a fairly longer time due to the stable Mg-O bonds. Mg species adsorbed on the inner sphere got rooted onto the hydroxyl layer, healing the damaged silicate-aluminate structures and stabilizing the network by inhibiting Na ion immigration into the solution. Mg ions in the outer layer, on average, associated with around one neighboring SO4 ion, forming ionic pairs and accumulating into large Mg-SO4 clusters, to help the immobilization of sulfate ions on the NASH surface.
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Affiliation(s)
- Yu Zhang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China.
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16
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Berg MC, Benetti AR, Telling MTF, Seydel T, Yu D, Daemen LL, Bordallo HN. Nanoscale Mobility of Aqueous Polyacrylic Acid in Dental Restorative Cements. ACS APPLIED MATERIALS & INTERFACES 2018; 10:9904-9915. [PMID: 29504390 DOI: 10.1021/acsami.7b15735] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hydrogen dynamics in a time range from hundreds of femtoseconds to nanoseconds can be directly analyzed using neutron spectroscopy, where information on the inelastic and quasi-elastic scattering, hereafter INS and QENS, can be obtained. In this study, we applied these techniques to understand how the nanoscale mobility of the aqueous solution of polyacrylic acid (PAA) used in conventional glass ionomer cements (GICs) changes under confinement. Combining the spectroscopic analysis with calorimetric results, we were able to separate distinct motions within both the liquid and the GICs. The QENS analysis revealed that the self-diffusion translational motion identified in the liquid is also visible in the GIC. However, as a result of the formation of the cement matrix and its setting, both translational diffusion and residence time differed from the PAA solution. When comparing the local diffusion obtained for the selected GIC, the only noticeable difference was observed for the slow dynamics associated with the polymer chain. Additionally, over short-term aging, progressive water binding to the polymer chain occurred in one of the investigated GICs. Finally, a considerable change in the density of the GIC without progressive water binding indicates an increased polymer cross-linking. Taken together, our results suggest that accurate and deep understanding of polymer-water binding, polymer cross-linking, as well as material density changes occurring during the maturation process of GIC are necessary for the development of advanced dental restorative materials.
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Affiliation(s)
- Marcella C Berg
- The Niels Bohr Institute , University of Copenhagen , DK-2100 Copenhagen , Denmark
- European Spallation Source ESS ERIC , P.O. Box 176 , SE-221 00 Lund , Sweden
| | - Ana R Benetti
- Department of Odontology, Faculty of Health and Medical Sciences , University of Copenhagen , DK-2200 Copenhagen , Denmark
| | - Mark T F Telling
- ISIS Facility , Rutherford Appleton Laboratory , Chilton, Oxford OX11 0QX , U.K
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , U.K
| | - Tilo Seydel
- Institut Max von Laue-Paul Langevin , CS 20156 , F-38042 Grenoble , France
| | - Dehong Yu
- Australian Nuclear Science and Technology Organisation , New Illawarra Road , Lucas Heights , New South Wales 2234 , Australia
| | - Luke L Daemen
- Oak Ridge National Laboratory , P.O. Box 2008 , Oak Ridge , Tennessee 37831 , United States
| | - Heloisa N Bordallo
- The Niels Bohr Institute , University of Copenhagen , DK-2100 Copenhagen , Denmark
- European Spallation Source ESS ERIC , P.O. Box 176 , SE-221 00 Lund , Sweden
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17
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Hajilar S, Shafei B. Atomic-scale investigation of physical adsorption of water molecules and aggressive ions to ettringite's surfaces. J Colloid Interface Sci 2018; 513:104-116. [PMID: 29132102 DOI: 10.1016/j.jcis.2017.09.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/31/2017] [Accepted: 09/02/2017] [Indexed: 11/15/2022]
Abstract
The strength and durability of cementitious composite materials are adversely affected by the ingress of water molecules and aggressive ions into their intrinsic meso- and nano-pore spaces. Among various phases of hydrated cement paste (HCP), aluminum-rich phases play an important role in controlling the diffusivity of aqueous solutions, which can contain aggressive ions. To this date, however, there has been no systematic study to understand the adsorption mechanisms and chloride binding capacity of the aluminum-rich phases of HCP. This research gap has been the motivation of the current study to investigate the physical adsorption characteristics of ettringite as the main aluminum-rich phase of HCP and the primary hydrated product of calcium sulfoaluminate cement. Through a set of Molecular Dynamics simulations supported by macro-scale experimental tests, a fundamental insight into the molecular origins of the diffusion of water molecules, as well as sodium and chloride ions, in contact with ettringite is provided. As the primary objective of this study is to evaluate the transport properties at and near solution/solid interfaces, the molecular adsorption mechanisms are characterized for inner- and outer-sphere distances from the solid substrate. With an in-depth understanding of the structure and dynamics of water molecules and aggressive ions in contact with ettringite's surfaces, the outcome of this study provides reliable measures of physical adsorption, binding capacity, and self-diffusion coefficient, which can be further employed to introduce strategies to avoid the degradation of a wide variety of cementitious materials exposed to harsh environmental conditions.
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Affiliation(s)
- Shahin Hajilar
- Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50011-1066, United States.
| | - Behrouz Shafei
- Department of Civil, Construction and Environmental Engineering, Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-1066, United States.
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18
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Prishchenko DA, Zenkov EV, Mazurenko VV, Fakhrullin RF, Lvov YM, Mazurenko VG. Molecular dynamics of the halloysite nanotubes. Phys Chem Chem Phys 2018; 20:5841-5849. [PMID: 29412207 DOI: 10.1039/c7cp06575b] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report large-scale and long-time molecular dynamics simulations demonstrating the transformation of a single kaolin alumosilicate sheet to a halloysite nanotube. The models we consider contain up to 5 × 105 atoms, which is two orders of magnitude larger than that used in previous theoretical works. It was found that the temperature plays a crucial role in the formation of the rolled geometry of the halloysite. For the models with periodic boundary conditions, we observe the tendency to form twin-tube structures, which is confirmed experimentally by atomic force microscopy imaging. The molecular dynamics calculations show that the rate of the rolling process is very sensitive to the choice of the winding axis and varies from 5 ns to 25 ns. The effects of the open boundary conditions and the initial form of the kaolin alumosilicate sheet are discussed. Our simulation results are consistent with experimental TEM and AFM halloysite tube imaging.
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Affiliation(s)
- Danil A Prishchenko
- Theoretical Physics and Applied Mathematics Department, Ural Federal University, Mira Str. 19, Ekaterinburg, Russia.
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19
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Ridi F, Tonelli M, Fratini E, Chen SH, Baglioni P. Water as a Probe of the Colloidal Properties of Cement. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:2205-2218. [PMID: 29035549 DOI: 10.1021/acs.langmuir.7b02304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cement is produced by mixing mineral phases based on calcium silicates and aluminates with water. The hydration reaction of the mixture leads to a synthetic material with outstanding properties that can be used as a binder for construction applications. Despite the importance of cement in society, for a long time, the chemical reactions involved in its hydration remained poorly understood as a result of the complexity of hydration processes, nanostructure, and transport phenomena. This feature article reviews the recently obtained results using water as a probe to detail the essential features in the setting process. By examining the peculiar physicochemical properties of water, fundamental information on the evolving inorganic colloid matrix can be deduced, ranging from the fractal nanostructure of the inorganic silicate framework to the transport phenomena inside the developing porosity. A similar approach can be transferred to the investigation of a plethora of other complex systems, where water plays the main role in determining the final structural and transport properties (i.e., biomaterials, hydrogels, and colloids).
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Affiliation(s)
- Francesca Ridi
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence , via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence, Italy
| | - Monica Tonelli
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence , via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence, Italy
| | - Emiliano Fratini
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence , via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence, Italy
| | - Sow-Hsin Chen
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Piero Baglioni
- Department of Chemistry "Ugo Schiff" and CSGI, University of Florence , via della Lastruccia 3-Sesto Fiorentino, I-50019 Florence, Italy
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20
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Faux DA, McDonald PJ, Howlett NC. Nuclear-magnetic-resonance relaxation due to the translational diffusion of fluid confined to quasi-two-dimensional pores. Phys Rev E 2017; 95:033116. [PMID: 28415296 DOI: 10.1103/physreve.95.033116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 01/09/2023]
Abstract
Nuclear-magnetic-resonance (NMR) relaxation experimentation is an effective technique for nondestructively probing the dynamics of proton-bearing fluids in porous media. The frequency-dependent relaxation rate T_{1}^{-1} can yield a wealth of information on the fluid dynamics within the pore provided data can be fit to a suitable spin diffusion model. A spin diffusion model yields the dipolar correlation function G(t) describing the relative translational motion of pairs of ^{1}H spins which then can be Fourier transformed to yield T_{1}^{-1}. G(t) for spins confined to a quasi-two-dimensional (Q2D) pore of thickness h is determined using theoretical and Monte Carlo techniques. G(t) shows a transition from three- to two-dimensional motion with the transition time proportional to h^{2}. T_{1}^{-1} is found to be independent of frequency over the range 0.01-100 MHz provided h≳5 nm and increases with decreasing frequency and decreasing h for pores of thickness h<3 nm. T_{1}^{-1} increases linearly with the bulk water diffusion correlation time τ_{b} allowing a simple and direct estimate of the bulk water diffusion coefficient from the high-frequency limit of T_{1}^{-1} dispersion measurements in systems where the influence of paramagnetic impurities is negligible. Monte Carlo simulations of hydrated Q2D pores are executed for a range of surface-to-bulk desorption rates for a thin pore. G(t) is found to decorrelate when spins move from the surface to the bulk, display three-dimensional properties at intermediate times, and finally show a bulk-mediated surface diffusion (Lévy) mechanism at longer times. The results may be used to interpret NMR relaxation rates in hydrated porous systems in which the paramagnetic impurity density is negligible.
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Affiliation(s)
- D A Faux
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - P J McDonald
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - N C Howlett
- Department of Physics, University of Surrey, Guildford GU2 7XH, United Kingdom
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21
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Hou D, Hu C, Li Z. Molecular Simulation of the Ions Ultraconfined in the Nanometer-Channel of Calcium Silicate Hydrate: Hydration Mechanism, Dynamic Properties, and Influence on the Cohesive Strength. Inorg Chem 2017; 56:1881-1896. [PMID: 28151682 DOI: 10.1021/acs.inorgchem.6b02456] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactive force field molecular dynamics was utilized to investigate the structure, dynamics, and mechanical nature of different cations solvated in the nanometer-channel of highly disordered calcium silicate hydrate. The local structures of different cations bonded with hydroxyl groups are characterized by the long spatial correlation, bond angel distribution preference, and featured coordinated number, resembling those of the tetra-/penta-/octahedron for cation-oxygen structure in the defective region of the silicate glass. Al atoms in the interlayer region play a role in bridging the defective silicate chains and enhance the connectivity of the silicate skeleton. Dynamically, the mobility of ultraconfined water molecules and cations is significantly influenced by the ionic chemistry: the residence time for water molecules in the hydration shell of Al and Mg ions is longer than that in the environment of Na and Ca ions. Furthermore, uniaxial tension simulation provides insight that while both the stiffness and cohesive strength of the C-S-H gels are significantly improved due to the silicate-aluminate branch structure formation, sodium ions with unstable Na-O connection weaken the loading resistance of the C-S-H gels. During the tensile process, the hydrolytic reaction is also affected by the cationic type: water molecules coordinated with Al and Mg cations at high stress state are likely to decompose, but those aggregated with sodium ions are hard to be stretched broken due to the low failure stress.
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Affiliation(s)
- Dongshuai Hou
- Department of Civil Engineering, Qingdao Technological University , Qingdao, China 266000
| | - Chuanlin Hu
- State Key Laboratory of Silicate Materials for Architecture, Wuhan University of Technology , Wuhan, China 430000
| | - Zongjin Li
- The Hong Kong University of Science and Technology , Clear Water Bay, Hong Kong, China 999077
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22
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Characteristic features of water dynamics in restricted geometries investigated with quasi-elastic neutron scattering. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2015.11.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Presti D, Pedone A, Mancini G, Duce C, Tiné MR, Barone V. Insights into structural and dynamical features of water at halloysite interfaces probed by DFT and classical molecular dynamics simulations. Phys Chem Chem Phys 2016; 18:2164-74. [DOI: 10.1039/c5cp05920h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory calculations and classical molecular dynamics simulations have been used to investigate the structure and dynamics of water molecules on kaolinite surfaces and confined in the interlayer of a halloysite model of nanometric dimension.
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Affiliation(s)
- Davide Presti
- Dipartimento di Scienze Chimiche e Geologiche
- Università di Modena e Reggio-Emilia
- I-41125 Modena
- Italy
| | - Alfonso Pedone
- Dipartimento di Scienze Chimiche e Geologiche
- Università di Modena e Reggio-Emilia
- I-41125 Modena
- Italy
| | | | - Celia Duce
- Dipartimento di Chimica e Chimica Industriale
- Università di Pisa
- Pisa
- Italy
| | - Maria Rosaria Tiné
- Dipartimento di Chimica e Chimica Industriale
- Università di Pisa
- Pisa
- Italy
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24
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Dongshuai H, Zeyu L, Peng Z, Qingjun D. Molecular structure and dynamics of an aqueous sodium chloride solution in nano-pores between portlandite surfaces: a molecular dynamics study. Phys Chem Chem Phys 2015; 18:2059-69. [PMID: 26687688 DOI: 10.1039/c5cp05884h] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Portlandite plays an important role in the hydration phase of cement-based materials and influences the strength and durability of such materials. This study describes a molecular dynamics study of the structure and dynamics of water and ions confined at ambient temperature in calcium hydroxyl nanopores with widths of 35 Å. Strong layering of water in the vicinity of the (001) surface of portlandite demonstrates special structural features such as large density, good orientation preference, ordered interfacial organization and low diffusion rate. Due to the fixed vibration and rotation of the hydroxyl groups at the interface, water molecules within the first adsorbed layer adopt both H-downward and H-upward orientations by donating H-bonds and accepting H-bonds from the OH groups in the solid surface. Regarding the interaction of the ions and portlandite, Na(+) ions, deeply rooted in spaces in the surface hydroxyl groups, are significantly slowed and remain near the surface for long periods of time. On the other hand, due to the weak H-bonds formed by chloride ions and hydroxyl groups, adsorbed chloride ions near the surface cannot remain for longer times. In addition, when water and ions are confined in the nano-pores, the residence time for the ion-water and ion-ion clusters is lengthened so that the ion adsorption capability of the porlandite surface is enhanced due to the stable Na-Cl connections in the electrolyte solution.
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25
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Miskowiec A, Anderson BB, Huq A, Mamontov E, Herwig KW, Trowbridge L, Rondinone A. Time-dependent water dynamics in hydrated uranyl fluoride. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1084056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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26
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Li H, Zhang LL, Yi Z, Fratini E, Baglioni P, Chen SH. Translational and rotational dynamics of water contained in aged Portland cement pastes studied by quasi-elastic neutron scattering. J Colloid Interface Sci 2015; 452:2-7. [PMID: 25898172 DOI: 10.1016/j.jcis.2015.04.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 04/03/2015] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
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27
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Shen Y, Peng B, Yang Y, Ma J, Haapasalo M. What do different tests tell about the mechanical and biological properties of bioceramic materials? ACTA ACUST UNITED AC 2015. [DOI: 10.1111/etp.12076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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28
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Hou D, Li Z, Zhao T, Zhang P. Water transport in the nano-pore of the calcium silicate phase: reactivity, structure and dynamics. Phys Chem Chem Phys 2015; 17:1411-23. [DOI: 10.1039/c4cp04137b] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structural and dynamic properties of surface water molecules.
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Affiliation(s)
- Dongshuai Hou
- Qingdao Technological University (Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone)
- Qingdao
- China
| | - Zongjin Li
- Qingdao Technological University (Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone)
- Qingdao
- China
| | - Tiejun Zhao
- Qingdao Technological University (Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone)
- Qingdao
- China
| | - Peng Zhang
- Qingdao Technological University (Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone)
- Qingdao
- China
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29
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Jacobsen J, Rodrigues MS, Telling MTF, Beraldo AL, Santos SF, Aldridge LP, Bordallo HN. Nano-scale hydrogen-bond network improves the durability of greener cements. Sci Rep 2014; 3:2667. [PMID: 24036676 PMCID: PMC3773627 DOI: 10.1038/srep02667] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 08/30/2013] [Indexed: 11/26/2022] Open
Abstract
More than ever before, the world's increasing need for new infrastructure demands the construction of efficient, sustainable and durable buildings, requiring minimal climate-changing gas-generation in their production. Maintenance-free “greener” building materials made from blended cements have advantages over ordinary Portland cements, as they are cheaper, generate less carbon dioxide and are more durable. The key for the improved performance of blends (which substitute fine amorphous silicates for cement) is related to their resistance to water penetration. The mechanism of this water resistance is of great environmental and economical impact but is not yet understood due to the complexity of the cement's hydration reactions. Using neutron spectroscopy, we studied a blend where cement was replaced by ash from sugar cane residuals originating from agricultural waste. Our findings demonstrate that the development of a distinctive hydrogen bond network at the nano-scale is the key to the performance of these greener materials.
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Affiliation(s)
- Johan Jacobsen
- 1] The Niels Bohr Institute, University of Copenhagen, DK-2100, Copenhagen, Denmark [2] European Spallation Source ESS AB P.O Box 176, SE-221 00 Lund, Sweden [3]
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30
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Qomi MJA, Bauchy M, Ulm FJ, Pellenq RJM. Anomalous composition-dependent dynamics of nanoconfined water in the interlayer of disordered calcium-silicates. J Chem Phys 2014; 140:054515. [DOI: 10.1063/1.4864118] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Li H, Fratini E, Chiang WS, Baglioni P, Mamontov E, Chen SH. Dynamic behavior of hydration water in calcium-silicate-hydrate gel: a quasielastic neutron scattering spectroscopy investigation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:061505. [PMID: 23367956 DOI: 10.1103/physreve.86.061505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Indexed: 06/01/2023]
Abstract
The translational dynamics of hydration water confined in calcium-silicate-hydrate (C-S-H) gel was studied by quasielastic neutron scattering spectroscopy in the temperature range from 280 to 230 K. The stretch exponent β, the self-diffusion constant D, the average translational relaxation time {τ}, and the temperature dependence of confinement radius α extracted from the elastic fraction of immobile water molecules p(Q) were obtained from the analyses of the low-Q spectra according to the relaxing cage model. Measurements were made using C-S-H of three different water contents, 10%, 17%, and 30%. Among the three samples of C-S-H gel with different water contents, the values of β decrease with increasing water contents, while α increases. The values of D and {τ} are insensitive to temperature for the two lower water contents, as opposed to the 30% case where a slight variation is observed. The trend for violation of the Stokes-Einstein relation is only visible in the case of 30% water content.
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Affiliation(s)
- Hua Li
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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32
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Cerveny S, Arrese-Igor S, Dolado JS, Gaitero JJ, Alegría A, Colmenero J. Effect of hydration on the dielectric properties of C-S-H gel. J Chem Phys 2011; 134:034509. [PMID: 21261370 DOI: 10.1063/1.3521481] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The behavior of water dynamics confined in hydrated calcium silicate hydrate (C-S-H) gel has been investigated using broadband dielectric spectroscopy (BDS; 10(-2)-10(6) Hz) in the low-temperature range (110-250 K). Different water contents in C-S-H gel were explored (from 6 to 15 wt%) where water remains amorphous for all the studied temperatures. Three relaxation processes were found by BDS (labeled 1 to 3 from the fastest to the slowest), two of them reported here for the first time. We show that a strong change in the dielectric relaxation of C-S-H gel occurs with increasing hydration, especially at a hydration level in which a monolayer of water around the basic units of cement materials is predicted by different structural models. Below this hydration level both processes 2 and 3 have an Arrhenius temperature dependence. However, at higher hydration level, a non-Arrhenius behavior temperature dependence for process 3 over the whole accessible temperature range and, a crossover from low-temperature Arrhenius to high-temperature non-Arrhenius behavior for process 2 are observed. Characteristics of these processes will be discussed in this work.
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Affiliation(s)
- Silvina Cerveny
- Centro de Fisica de Materiales (CSIC, UPV∕EHU), Paseo Manuel de Lardizabal 5, 20018, San Sebastián, Spain.
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33
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Cement: A two thousand year old nano-colloid. J Colloid Interface Sci 2011; 357:255-64. [DOI: 10.1016/j.jcis.2011.02.026] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 02/07/2011] [Accepted: 02/08/2011] [Indexed: 11/18/2022]
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34
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Youssef M, Pellenq RJM, Yildiz B. Glassy nature of water in an ultraconfining disordered material: the case of calcium-silicate-hydrate. J Am Chem Soc 2011; 133:2499-510. [PMID: 21294516 DOI: 10.1021/ja107003a] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present the structural and dynamic nature of water ultraconfined in the quasi-two-dimensional nanopores of the highly disordered calcium-silicate-hydrate (C-S-H), the major binding phase in cement. Our approach is based on classical molecular simulations. We demonstrate that the C-S-H nanopore space is hydrophilic, particularly because of the nonbridging oxygen atoms on the disordered silicate chains which serve as hydrogen-bond acceptor sites, directionally orienting the hydrogen atoms of the interfacial water molecules toward the calcium-silicate layers. The water in this interlayer space adopts a unique multirange structure: a distorted tetrahedral coordination at short range up to 2.7 Å, a disordered structure similar to that of dense fluids and supercooled phases at intermediate range up to 4.2 Å, and persisting spatial correlations through dipole-dipole interactions up to 10 Å. A three-stage dynamics governs the mean square displacement (MSD) of water molecules, with a clear cage stage characteristic of the dynamics in supercooled liquids and glasses, consistent with its intermediate-range structure identified here. At the intermediate time scales corresponding to the β-relaxation of glassy materials, coincident with the cage stage in MSD, the non-Gaussian parameter indicates a significant heterogeneity in the translational dynamics. This dynamic heterogeneity is induced primarily because of the heterogeneity in the distribution of hydrogen bond strengths. The strongly attractive interactions of water molecules with the calcium silicate walls serve to constrain their motion. Our findings have important implications on describing the cohesion and mechanical behavior of cement from its setting to its aging.
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Affiliation(s)
- Mostafa Youssef
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Bordallo HN, Aldridge LP. Concrete and Cement Paste Studied by Quasi-Elastic Neutron Scattering. ACTA ACUST UNITED AC 2010. [DOI: 10.1524/zpch.2010.6098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
In a world where the effects of climate change on weather patterns is accepted as real and serious, the problem of decreasing the production of carbon dioxide is perceived as increasingly important. The cement industry produces 5–7% of the world’s carbon dioxide emission and its survival will depend on improvements in the production of concrete which will be both more durable and require less carbon dioxide per unit of manufacture than the currently produced concrete. The durability of concrete is related to its ability to limit fluid transmission and knowledge of how to reduce the rate at which water will be transmitted through cement paste is critical to improving durability. However, because of the complex chemical and physical nature of cement pastes, understanding water mobility is a great challenge. Many techniques are not applicable simply because they are not sensitive to the range of size from angstroms to microns and the extent of water interaction with the cement where water can either be chemically bound at hydroxyls or physically free in large pores. In this review paper, we present the most up to date results on the physical chemistry of the water/ cement paste interactions studied by quasi-elastic neutron scattering. These results bring new insight to the mobility of water in the gel pores, the small pores (radius less than 50Å) that control the rate of water transmission in the cement pastes from which high quality concrete will be made.
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Bordallo HN, Aldridge LP, Fouquet P, Pardo LC, Unruh T, Wuttke J, Yokaichiya F. Hindered water motions in hardened cement pastes investigated over broad time and length scales. ACS APPLIED MATERIALS & INTERFACES 2009; 1:2154-2162. [PMID: 20355849 DOI: 10.1021/am900332n] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We investigated the dynamics of confined water in different hydrated cement pastes with minimized contributions of capillary water. It was found that the water motions are extremely reduced compared to those of bulk water. The onset of water mobility, which was modified by the local environment, was investigated with elastic temperature scans using the high-resolution neutron backscattering instrument SPHERES. Using a Cauchy-Lorenz distribution, the quasi-elastic signal observed in the spectra obtained by the backscattering spectrometer was analyzed, leading to the identification of rotational motions with relaxation times of 0.3 ns. Additionally, neutron spin echo (NSE) spectroscopy was used to measure the water diffusion over the local network of pores. The motions observed in the NSE time scale were characterized by diffusion constants ranging from 0.6 to 1.1 x 10(-9) m(2) s(-1) most likely related to water molecules removed from the interface. In summary, our results indicate that the local diffusion observed in the gel pores of hardened cement pastes is on the order of that found in deeply supercooled water. Finally, the importance of the magnetic properties of cement pastes were discussed in relation to the observation of a quasi-elastic signal on the dried sample spectra measured using the time-of-flight spectrometer.
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Affiliation(s)
- Heloisa N Bordallo
- Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH, Glienicker Strasse 100, D-14109 Berlin, Germany.
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González Sánchez F, Jurányi F, Gimmi T, Van Loon L, Unruh T, Diamond LW. Translational diffusion of water and its dependence on temperature in charged and uncharged clays: A neutron scattering study. J Chem Phys 2008; 129:174706. [DOI: 10.1063/1.3000638] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jalarvo N, Bordallo HN, Aliouane N, Adams MA, Pieper J, Argyriou DN. Dynamics of Water in NaxCoO2·yH2O. J Phys Chem B 2007; 112:703-9. [DOI: 10.1021/jp074398y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Niina Jalarvo
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
| | - Heloisa N. Bordallo
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
| | - Nadir Aliouane
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
| | - Mark A. Adams
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
| | - Jörg Pieper
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
| | - Dimitri N. Argyriou
- Hahn-Meitner Institut, Glienicker Strasse 100, 14109 Berlin, Germany, Institut Laue Langevin, B.P. 156, 38042 Grenoble, Cedex 9, France, ISIS Pulsed Neutron Scattering Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX, U.K., and Technische Universität Berlin, Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Strasse des 17. Juni 135 10623 Berlin, Germany
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Nekoofar MH, Adusei G, Sheykhrezae MS, Hayes SJ, Bryant ST, Dummer PMH. The effect of condensation pressure on selected physical properties of mineral trioxide aggregate. Int Endod J 2007; 40:453-61. [PMID: 17459121 DOI: 10.1111/j.1365-2591.2007.01236.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM To examine the effect of condensation pressure on surface hardness, microstructure and compressive strength of mineral trioxide aggregate (MTA). METHODOLOGY White ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN, USA) was mixed and packed into cylindrical polycarbonate tubes. Six groups each of 10 specimens were subjected to pressures of 0.06, 0.44, 1.68, 3.22, 4.46 and 8.88 MPa respectively. The surface hardness of each specimen was measured using Vickers microhardness. Cylindrical specimens of 4 mm in diameter and 6 mm in height were prepared in polycarbonate cylindrical moulds for testing the compressive strength. Five groups of 10 specimens were prepared using pressures of 0.06, 0.44, 1.68, 3.22 or 4.46 MPa. Data were subjected to one-way anova. The microstructure was analysed using a scanning electron microscope (SEM) after sectioning specimens with a scalpel. RESULT A trend was observed for higher condensation pressures to produce lower surface hardness values. A condensation pressure of 8.88 MPa produced specimens with significantly lower values in terms of surface hardness than other groups (P<0.001). A condensation pressure of 1.68 MPa conferred the maximum compressive strength; however, it was not statistically different. Higher condensation pressures resulted in fewer voids and microchannels when analysed with SEM. In specimens prepared with lower condensation pressures distinctive crystalline structures were observed. They tended to appear around microchannels. CONCLUSION Condensation pressure may affect the strength and hardness of MTA. Use of controlled condensation pressure in sample preparation for future studies is suggested.
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Affiliation(s)
- M H Nekoofar
- Endodontology Research Group, School of Dentistry, Cardiff University, Cardiff, UK.
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