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Jia X, Xin Z, Fu Y, Duan H. Theoretical Investigation into Polymorphic Transformation between β-HMX and δ-HMX by Finite Temperature String. Molecules 2024; 29:4819. [PMID: 39459188 PMCID: PMC11510520 DOI: 10.3390/molecules29204819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 09/04/2024] [Revised: 10/05/2024] [Accepted: 10/09/2024] [Indexed: 10/28/2024] Open
Abstract
Polymorphic transformation is important in chemical industries, in particular, in those involving explosive molecular crystals. However, due to simulating challenges in the rare event method and collective variables, understanding the transformation mechanism of molecular crystals with a complex structure at the molecular level is poor. In this work, with the constructed order parameters (OPs) and K-means clustering algorithm, the potential of mean force (PMF) along the minimum free-energy path connecting β-HMX and δ-HMX was calculated by the finite temperature string method in the collective variables (SMCV), the free-energy profile and nucleation kinetics were obtained by Markovian milestoning with Voronoi tessellations, and the temperature effect on nucleation was also clarified. The barriers of transformation were affected by the finite-size effects. The configuration with the lower potential barrier in the PMF corresponded to the critical nucleus. The time and free-energy barrier of the polymorphic transformation were reduced as the temperature increased, which was explained by the pre-exponential factor and nucleation rate. Thus, the polymorphic transformation of HMX could be controlled by the temperatures, as is consistent with previous experimental results. Finally, the HMX polymorph dependency of the impact sensitivity was discussed. This work provides an effective way to reveal the polymorphic transformation of the molecular crystal with a cyclic molecular structure, and further to prepare the desired explosive by controlling the transformation temperature.
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Affiliation(s)
- Xiumei Jia
- School of Innovation and Entrepreneurship, North University of China, Taiyuan 030051, China
| | - Zhendong Xin
- Department of Admission and Employment, North University of China, Taiyuan 030051, China;
| | - Yizheng Fu
- School of Materials Science and Engineering, North University of China, Taiyuan 030051, China; (Y.F.); (H.D.)
| | - Hongji Duan
- School of Materials Science and Engineering, North University of China, Taiyuan 030051, China; (Y.F.); (H.D.)
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Niu SJ, Ren FD. Finite Temperature String with Order Parameter as Collective Variables for Molecular Crystal: A Case of Polymorphic Transformation of TNT under External Electric Field. Molecules 2024; 29:2549. [PMID: 38893427 PMCID: PMC11173574 DOI: 10.3390/molecules29112549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 04/21/2024] [Revised: 05/08/2024] [Accepted: 05/08/2024] [Indexed: 06/21/2024] Open
Abstract
An external electric field is an effective tool to induce the polymorphic transformation of molecular crystals, which is important practically in the chemical, material, and energy storage industries. However, the understanding of this mechanism is poor at the molecular level. In this work, two types of order parameters (OPs) were constructed for the molecular crystal based on the intermolecular distance, bond orientation, and molecular orientation. Using the K-means clustering algorithm for the sampling of OPs based on the Euclidean distance and density weight, the polymorphic transformation of TNT was investigated using a finite temperature string (FTS) under external electric fields. The potential of mean force (PMF) was obtained, and the essence of the polymorphic transformation between o-TNT and m-TNT was revealed, which verified the effectiveness of the FTS method based on K-means clustering to OPs. The differences in PMFs between the o-TNT and transition state were decreased under external electric fields in comparison with those in no field. The fields parallel to the c-axis obviously affected the difference in PMF, and the relationship between the changes in PMFs and field strengths was found. Although the external electric field did not promote the convergence, the time of the polymorphic transformation was reduced under the external electric field in comparison to its absence. Moreover, under the external electric field, the polymorphic transformation from o-TNT to m-TNT occurred while that from m-TNT to o-TNT was prevented, which was explained by the dipole moment of molecule, relative permittivity, chemical potential difference, nucleation work and nucleation rate. This confirmed that the polymorphic transformation orientation of the molecular crystal could be controlled by the external electric field. This work provides an effective way to explore the polymorphic transformation of the molecular crystals at a molecular level, and it is useful to control the production process and improve the performance of energetic materials by using the external electric fields.
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Affiliation(s)
- Shi-Jie Niu
- School of Chemistry and Chemical Engineering, North University of China, Taiyuan 030051, China;
- School of Management, Wuhan Polytechnic University, Wuhan 430040, China
| | - Fu-De Ren
- School of Chemistry and Chemical Engineering, North University of China, Taiyuan 030051, China;
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Ren FD, Liu YZ, Ding KW, Chang LL, Cao DL, Liu S. Finite temperature string by K-means clustering sampling with order parameters as collective variables for molecular crystals: application to polymorphic transformation between β-CL-20 and ε-CL-20. Phys Chem Chem Phys 2024; 26:3500-3515. [PMID: 38206084 DOI: 10.1039/d3cp05389j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 01/12/2024]
Abstract
Polymorphic transformation of molecular crystals is a fundamental phase transition process, and it is important practically in the chemical, material, biopharmaceutical, and energy storage industries. However, understanding of the transformation mechanism at the molecular level is poor due to the extreme simulating challenges in enhanced sampling and formulating order parameters (OPs) as the collective variables that can distinguish polymorphs with quite similar and complicated structures so as to describe the reaction coordinate. In this work, two kinds of OPs for CL-20 were constructed by the bond distances, bond orientations and relative orientations. A K-means clustering algorithm based on the Euclidean distance and sample weight was used to smooth the initial finite temperature string (FTS), and the minimum free energy path connecting β-CL-20 and ε-CL-20 was sketched by the string method in collective variables, and the free energy profile along the path and the nucleation kinetics were obtained by Markovian milestoning with Voronoi tessellations. In comparison with the average-based sampling, the K-means clustering algorithm provided an improved convergence rate of FTS. The simulation of transformation was independent of OP types but was affected greatly by finite-size effects. A surface-mediated local nucleation mechanism was confirmed and the configuration located at the shoulder of potential of mean force, rather than overall maximum, was confirmed to be the critical nucleus formed by the cooperative effect of the intermolecular interactions. This work provides an effective way to explore the polymorphic transformation of caged molecular crystals at the molecular level.
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Affiliation(s)
- Fu-de Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China.
| | - Ying-Zhe Liu
- Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
| | - Ke-Wei Ding
- Xi'an Modern Chemistry Research Institute, Xi'an 710065, China
| | - Ling-Ling Chang
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China.
| | - Duan-Lin Cao
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China.
| | - Shubin Liu
- Research Computing Center, University of North Carolina, Chapel Hill, North Carolina 27599-3420, USA.
- Depaertment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA
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4
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Tonauer CM, Fidler LR, Giebelmann J, Yamashita K, Loerting T. Nucleation and growth of crystalline ices from amorphous ices. J Chem Phys 2023; 158:141001. [PMID: 37061482 DOI: 10.1063/5.0143343] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 04/17/2023] Open
Abstract
We here review mostly experimental and some computational work devoted to nucleation in amorphous ices. In fact, there are only a handful of studies in which nucleation and growth in amorphous ices are investigated as two separate processes. In most studies, crystallization temperatures Tx or crystallization rates RJG are accessed for the combined process. Our Review deals with different amorphous ices, namely, vapor-deposited amorphous solid water (ASW) encountered in many astrophysical environments; hyperquenched glassy water (HGW) produced from μm-droplets of liquid water; and low density amorphous (LDA), high density amorphous (HDA), and very high density amorphous (VHDA) ices produced via pressure-induced amorphization of ice I or from high-pressure polymorphs. We cover the pressure range of up to about 6 GPa and the temperature range of up to 270 K, where only the presence of salts allows for the observation of amorphous ices at such high temperatures. In the case of ASW, its microporosity and very high internal surface to volume ratio are the key factors determining its crystallization kinetics. For HGW, the role of interfaces between individual glassy droplets is crucial but mostly neglected in nucleation or crystallization studies. In the case of LDA, HDA, and VHDA, parallel crystallization kinetics to different ice phases is observed, where the fraction of crystallized ices is controlled by the heating rate. A key aspect here is that in different experiments, amorphous ices of different "purities" are obtained, where "purity" here means the "absence of crystalline nuclei." For this reason, "preseeded amorphous ice" and "nuclei-free amorphous ice" should be distinguished carefully, which has not been done properly in most studies. This makes a direct comparison of results obtained in different laboratories very hard, and even results obtained in the same laboratory are affected by very small changes in the preparation protocol. In terms of mechanism, the results are consistent with amorphous ices turning into an ultraviscous, deeply supercooled liquid prior to nucleation. However, especially in preseeded amorphous ices, crystallization from the preexisting nuclei takes place simultaneously. To separate the time scales of crystallization from the time scale of structure relaxation cleanly, the goal needs to be to produce amorphous ices free from crystalline ice nuclei. Such ices have only been produced in very few studies.
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Affiliation(s)
- Christina M Tonauer
- Institute of Physical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | - Lilli-Ruth Fidler
- Institute of Physical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | - Johannes Giebelmann
- Institute of Physical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | - Keishiro Yamashita
- Institute of Physical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, 6020 Innsbruck, Austria
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Tonauer CM, Bauer M, Loerting T. The impact of temperature and unwanted impurities on slow compression of ice. Phys Chem Chem Phys 2021; 24:35-41. [PMID: 34897324 PMCID: PMC8694060 DOI: 10.1039/d1cp03922a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 01/09/2023]
Abstract
For slowly compressed hexagonal ice pressure-induced amorphisation to high-density amorphous ice (HDA) takes place below and at 130 K, but polymorphic transformation to ice IX takes place at 140–170 K. Stable ice II only forms above 170 K. Ice IX impurities trigger ice IX growth even at 120 K. HDA and ice IX are equally long-lived, where both can be regarded as metastable phases. Slow compression of ice at 100 K usually results in pressure-amorphisation, unless there are ice IX seeds and temperature gradients.![]()
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Affiliation(s)
- Christina M Tonauer
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, Innsbruck A-6020, Austria.
| | - Marion Bauer
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, Innsbruck A-6020, Austria.
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, Innsbruck A-6020, Austria.
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Handle PH, Sciortino F, Giovambattista N. Glass polymorphism in TIP4P/2005 water: A description based on the potential energy landscape formalism. J Chem Phys 2019; 150:244506. [PMID: 31255050 DOI: 10.1063/1.5100346] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/15/2022] Open
Abstract
The potential energy landscape (PEL) formalism is a statistical mechanical approach to describe supercooled liquids and glasses. Here, we use the PEL formalism to study the pressure-induced transformations between low-density amorphous ice (LDA) and high-density amorphous ice (HDA) using computer simulations of the TIP4P/2005 molecular model of water. We find that the properties of the PEL sampled by the system during the LDA-HDA transformation exhibit anomalous behavior. In particular, at conditions where the change in density during the LDA-HDA transformation is approximately discontinuous, reminiscent of a first-order phase transition, we find that (i) the inherent structure (IS) energy, eIS(V), is a concave function of the volume and (ii) the IS pressure, PIS(V), exhibits a van der Waals-like loop. In addition, the curvature of the PEL at the IS is anomalous, a nonmonotonic function of V. In agreement with previous studies, our work suggests that conditions (i) and (ii) are necessary (but not sufficient) signatures of the PEL for the LDA-HDA transformation to be reminiscent of a first-order phase transition. We also find that one can identify two different regions of the PEL, one associated with LDA and another with HDA. Our computer simulations are performed using a wide range of compression/decompression and cooling rates. In particular, our slowest cooling rate (0.01 K/ns) is within the experimental rates employed in hyperquenching experiments to produce LDA. Interestingly, the LDA-HDA transformation pressure that we obtain at T = 80 K and at different rates extrapolates remarkably well to the corresponding experimental pressure.
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Affiliation(s)
- Philip H Handle
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Francesco Sciortino
- Department of Physics, Sapienza-University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Nicolas Giovambattista
- Department of Physics, Brooklyn College of the City University of New York, New York, New York 10016, USA
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Temperature-induced amorphization in CaCO 3 at high pressure and implications for recycled CaCO 3 in subduction zones. Nat Commun 2019; 10:1963. [PMID: 31036817 PMCID: PMC6488655 DOI: 10.1038/s41467-019-09742-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 11/12/2018] [Accepted: 03/05/2019] [Indexed: 11/08/2022] Open
Abstract
Calcium carbonate (CaCO3) significantly affects the properties of upper mantle and plays a key role in deep carbon recycling. However, its phase relations above 3 GPa and 1000 K are controversial. Here we report a reversible temperature-induced aragonite-amorphization transition in CaCO3 at 3.9-7.5 GPa and temperature above 1000 K. Amorphous CaCO3 shares a similar structure as liquid CaCO3 but with much larger C-O and Ca-Ca bond lengths, indicating a lower density and a mechanism of lattice collapse for the temperature-induced amorphous phase. The less dense amorphous phase compared with the liquid provides an explanation for the observed CaCO3 melting curve overturn at about 6 GPa. Amorphous CaCO3 is stable at subduction zone conditions and could aid the recycling of carbon to the surface.
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Abstract
We report a numerical study of the statistical properties of the potential energy landscape of TIP4P/2005, one of the most accurate rigid water models. We show that, in the region where equilibrated configurations can be generated, a Gaussian landscape description is able to properly describe the model properties. We also find that the volume dependence of the landscape properties is consistent with the existence of a locus of density maxima in the phase diagram. The landscape-based equation of state accurately reproduces the TIP4P/2005 pressure-vs-volume curves, providing a sound extrapolation of the free-energy at low T. A positive-pressure liquid-liquid critical point is predicted by the resulting free-energy.
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Affiliation(s)
- Philip H Handle
- Department of Physics, Sapienza-University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Francesco Sciortino
- Department of Physics, Sapienza-University of Rome, Piazzale Aldo Moro 5, I-00185 Roma, Italy
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9
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Lemke S, Handle PH, Plaga LJ, Stern JN, Seidl M, Fuentes-Landete V, Amann-Winkel K, Köster KW, Gainaru C, Loerting T, Böhmer R. Relaxation dynamics and transformation kinetics of deeply supercooled water: Temperature, pressure, doping, and proton/deuteron isotope effects. J Chem Phys 2018; 147:034506. [PMID: 28734291 DOI: 10.1063/1.4993790] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 12/27/2022] Open
Abstract
Above its glass transition, the equilibrated high-density amorphous ice (HDA) transforms to the low-density pendant (LDA). The temperature dependence of the transformation is monitored at ambient pressure using dielectric spectroscopy and at elevated pressures using dilatometry. It is found that near the glass transition temperature of deuterated samples, the transformation kinetics is 300 times slower than the structural relaxation, while for protonated samples, the time scale separation is at least 30 000 and insensitive to doping. The kinetics of the HDA to LDA transformation lacks a proton/deuteron isotope effect, revealing that this process is dominated by the restructuring of the oxygen network. The x-ray diffraction experiments performed on samples at intermediate transition stages reflect a linear combination of the LDA and HDA patterns implying a macroscopic phase separation, instead of a local intermixing of the two amorphous states.
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Affiliation(s)
- Sonja Lemke
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Philip H Handle
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Lucie J Plaga
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Josef N Stern
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Markus Seidl
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | | | - Katrin Amann-Winkel
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Karsten W Köster
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Catalin Gainaru
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, A-6020 Innsbruck, Austria
| | - Roland Böhmer
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
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Handle PH, Sciortino F. The Adam-Gibbs relation and the TIP4P/2005 model of water. Mol Phys 2018; 116:3366-3371. [PMID: 30338319 PMCID: PMC6171618 DOI: 10.1080/00268976.2018.1471230] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Academic Contribution Register] [Received: 02/27/2018] [Accepted: 04/18/2018] [Indexed: 11/24/2022]
Abstract
We report a numerical test of the Adam-Gibbs relation for the TIP4P/2005 model of water. The configurational entropy is here evaluated as the logarithm of the number of different basins in the potential energy landscape sampled in equilibrium conditions. Despite the non-monotonic behaviour which characterise the density dependence of the diffusion coefficient, the Adam-Gibbs relation is satisfied within the numerical precision in a wide range of densities and temperatures. We also show that expressions based on the excess entropy (the logarithm of the number of sampled microstates in phase space) fail in the region of densities where a tetrahedral hydrogen bond network develops.
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Handle PH, Loerting T. Experimental study of the polyamorphism of water. I. The isobaric transitions from amorphous ices to LDA at 4 MPa. J Chem Phys 2018; 148:124508. [DOI: 10.1063/1.5019413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Philip H. Handle
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
| | - Thomas Loerting
- Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria
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12
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Supercooled and glassy water: Metastable liquid(s), amorphous solid(s), and a no-man's land. Proc Natl Acad Sci U S A 2017; 114:13336-13344. [PMID: 29133419 DOI: 10.1073/pnas.1700103114] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/18/2022] Open
Abstract
We review the recent research on supercooled and glassy water, focusing on the possible origins of its complex behavior. We stress the central role played by the strong directionality of the water-water interaction and by the competition between local energy, local entropy, and local density. In this context we discuss the phenomenon of polyamorphism (i.e., the existence of more than one disordered solid state), emphasizing both the role of the preparation protocols and the transformation between the different disordered ices. Finally, we present the ongoing debate on the possibility of linking polyamorphism with a liquid-liquid transition that could take place in the no-man's land, the temperature-pressure window in which homogeneous nucleation prevents the investigation of water in its metastable liquid form.
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Johari GP, Teixeira J. Thermodynamic Analysis of the Two-Liquid Model for Anomalies of Water, HDL-LDL Fluctuations, and Liquid-Liquid Transition. J Phys Chem B 2015; 119:14210-20. [PMID: 26436324 DOI: 10.1021/acs.jpcb.5b06458] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Academic Contribution Register] [Indexed: 11/28/2022]
Abstract
After reviewing the protocol-dependent properties of HDA, which thermally anneals to LDA, and the data gap over an unusually large T-range between HDA, LDA, and water, we investigate whether or not, despite HDA's ill-defined state and distinction from a glass, the HDL-LDL fluctuations view of the two-liquid model can explain water's anomalous behavior. An analysis of the density, ρ, compressibility, β, heat capacity, Cp, and thermal conductivity, κ, of water over a monotonic (continuous) path bridging this data gap shows the following: (i) Such a path between ρwater at 320 K and ρHDA yields an untenable thermal expansion coefficient of water. (ii) There is neither a continuous path between βwater at 353 K and βHDA, nor between Cp,water at 363 K and Cp,HDA. (iii) The same value of ρwater, of βwater, or of Cp,water at two temperatures separated by a maxima or a minima is incompatible with the HDL-LDL fluctuations view. (iv) κLDA at ∼140 K is about twice that of κ water at 253 K. (v) κHDA at 120 K is incompatible with κwater at T > 320 K. Thus, there is an internal inconsistency between the thermodynamics of HDA seen as a glass and that of water seen as an HDL-LDL mixture, which is incompatible with both the HDL-LDL fluctuations view and the liquid-liquid transition.
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Affiliation(s)
- G P Johari
- Department of Materials Science and Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada.,Laboratoire Léon Brillouin (CEA/CNRS), CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
| | - J Teixeira
- Department of Materials Science and Engineering, McMaster University , Hamilton, Ontario L8S 4L7, Canada.,Laboratoire Léon Brillouin (CEA/CNRS), CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
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