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Hansen C, Zhou W, Brack E, Wang Y, Wang C, Paterson J, Southouse J, Copéret C. Decoding the Promotional Effect of Iron in Bimetallic Pt-Fe-nanoparticles on the Low Temperature Reverse Water-Gas Shift Reaction. J Am Chem Soc 2024; 146:27555-27562. [PMID: 39347826 DOI: 10.1021/jacs.4c08517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
The reverse water-gas shift (RWGS) reaction is a key technology of the chemical industry, central to the emerging circular carbon economy. Pt-based catalysts have previously been shown to effectively promote RWGS, especially when modified by promoter elements. However, their active states are still poorly understood. Here, we show that the intimate incorporation of an iron promoter into metal-oxide-supported Pt-based nanoparticles can increase their activity and selectivity for the low temperature reverse water-gas shift (LT-RWGS) substantially and drastically outperform unpromoted Pt-based materials. Specifically, the study explores the promotional effect of iron in Pt-Fe bimetallic systems supported on silica (PtxFey@SiO2) prepared by surface organometallic chemistry (SOMC). The most active catalyst (Pt1Fe1@SiO2) shows high selectivity (>99% CO) toward CO at a formation rate of 0.192 molCO h-1 gcat-1, which is significantly higher than that of monometallic Pt@SiO2 (96% sel. and 0.022 molCO h-1 gcat-1). In-situ diffuse reflectance FT-IR spectroscopy (DRIFTS) and X-ray absorption spectroscopy (XAS) indicate a dynamic process at the catalyst surface under the reaction conditions, revealing distinct reaction pathways for the monometallic Pt@SiO2 and bimetallic PtxFey@SiO2 systems.
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Affiliation(s)
- Colin Hansen
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
| | - Wei Zhou
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
| | - Enzo Brack
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
| | - Yuhao Wang
- Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, China
| | - Chunliang Wang
- Engineering Research Center of Metallurgical Energy Conservation and Emission Reduction, Ministry of Education, Kunming University of Science and Technology, Kunming 650093, China
| | - James Paterson
- bp Technology, Applied Sciences bp plc Saltend, Hull HU12 8DS, United Kingdom
| | - Jamie Southouse
- bp Technology, Applied Sciences bp plc Saltend, Hull HU12 8DS, United Kingdom
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1-5, Zurich CH-8093, Switzerland
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2
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Ding Y, Xiao Y, Huang G, Chen W, Li C. Kinetic research of red mud waste oxidative pyrolysis and comparison under different atmospheres. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 370:122752. [PMID: 39366223 DOI: 10.1016/j.jenvman.2024.122752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Revised: 09/14/2024] [Accepted: 09/29/2024] [Indexed: 10/06/2024]
Abstract
Red mud, as a solid waste with high alkalinity, had a detrimental impact on the environment and required urgent attention. Currently, the mass processing and consumption of red mud were typically conducted under thermal conditions, so it was essential to gain a comprehensive understanding of the oxidative pyrolysis process. The thermogravimetric experiments were conducted at multiple heating rates in air and exhibited three obvious stages. The activation energy and reaction mechanism of three oxidative pyrolysis stages were explored using model-free and model-fitting methods, revealing the activation energies of 162.2, 265.8, 214.1 kJ/mol and the most suitable reaction mechanisms of g(α)=[-ln(1-α)]³, g(α)=1-(1-α)1/⁴, g(α)=[-ln(1-α)]1/2 for each stage, respectively. Furthermore, the estimated kinetic parameters and reaction mechanisms were applied to extra heating rate to verify the accuracy. More important, the effect of air on the pyrolysis process of red mud was examined by comparing the results with those obtained from pure nitrogen pyrolysis. The obtained oxidative pyrolysis characteristics of red mud could provide valuable insights of its co-pyrolysis or combustion for resources recycling.
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Affiliation(s)
- Yanming Ding
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China; Institute for Natural Disaster Risk Prevention and Emergency Management, China University of Geosciences, Wuhan, 430074, China.
| | - Ying Xiao
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Guozhe Huang
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Wenlu Chen
- Faculty of Engineering, China University of Geosciences, Wuhan, 430074, China
| | - Changhai Li
- State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei, 230027, China
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3
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Kato K, Hotta M, Koga N. Water vapor effect on the physico-geometrical reaction pathway and kinetics of the multistep thermal dehydration of calcium chloride dihydrate. Phys Chem Chem Phys 2024; 26:18476-18492. [PMID: 38916484 DOI: 10.1039/d4cp01870b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
This study investigated how water vapor influences the reaction pathway and kinetics of the multistep thermal dehydration of inorganic hydrates, focusing on CaCl2·2H2O (CC-DH) transforming into its anhydride (CC-AH) via an intermediate of its monohydrate (CC-MH). In the presence of atmospheric water vapor, the thermal dehydration of CC-DH stoichiometrically proceeded through two distinct steps, resulting in the formation of CC-AH via CC-MH under isothermal conditions and linear nonisothermal conditions at a lower heating rate (β). Irrespective of atmospheric water vapor pressure (p(H2O)), these reaction steps were kinetically characterized by a physico-geometrical consecutive process involving the surface reaction and phase boundary-controlled reaction, which was accompanied by three-dimensional shrinkage of the reaction interface. In addition, a significant induction period was observed for the second reaction step, that is, the thermal dehydration of CC-MH intermediate to form CC-AH. With increasing p(H2O), a systematic increase in the apparent Arrhenius parameters was observed for the first reaction step, that is, the thermal dehydration of CC-DH to form CC-MH, whereas the second reaction step exhibited unsystematic variations of the Arrhenius parameters. At a larger β in the presence of atmospheric water vapor, the first and second reaction steps partially overlapped; moreover, an alternative reaction step of the thermal dehydration of CC-MH to form CaCl2·0.3H2O was observed between these reaction steps. The physico-geometrical phenomena influencing the reaction pathway and kinetics of the multistep thermal dehydration were elucidated by considering the effects of atmospheric and self-generated water vapor in a geometrically constrained reaction scheme.
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Affiliation(s)
- Kazuki Kato
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Mito Hotta
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Nobuyoshi Koga
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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4
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Ogbomo E, Bhuiyan FH, Latorre CA, Martini A, Ewen JP. Effects of surface chemistry on the mechanochemical decomposition of tricresyl phosphate. Phys Chem Chem Phys 2023; 26:278-292. [PMID: 38059507 DOI: 10.1039/d3cp05320b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The growth of protective tribofilms from lubricant antiwear additives on rubbing surfaces is initiated by mechanochemically promoted dissociation reactions. These processes are not well understood at the molecular scale for many important additives, such as tricresyl phosphate (TCP). One aspect that needs further clarification is the extent to which the surface properties affect the mechanochemical decomposition. Here, we use nonequilibrium molecular dynamics (NEMD) simulations with a reactive force field (ReaxFF) to study the decomposition of TCP molecules confined and pressurised between sliding ferrous surfaces at a range of temperatures. We compare the decomposition of TCP on native iron, iron carbide, and iron oxide surfaces. We show that the decomposition rate of TCP molecules on all the surfaces increases exponentially with temperature and shear stress, implying that this is a stress-augmented thermally activated (SATA) process. The presence of base oil molecules in the NEMD simulations decreases the shear stress, which in turn reduces the rate constant for TCP decomposition. The decomposition is much faster on iron surfaces than iron carbide, and particularly iron oxide. The activation energy, activation volume, and pre-exponential factor from the Bell model are similar on iron and iron carbide surfaces, but significantly differ for iron oxide surfaces. These findings provide new insights into the mechanochemical decomposition of TCP and have important implications for the design of novel lubricant additives for use in high-temperature and high-pressure environments.
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Affiliation(s)
- Egheosa Ogbomo
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
- The Thomas Young Centre, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
| | - Fakhrul H Bhuiyan
- Department of Mechanical Engineering, University of California-Merced, 5200 N. Lake Road, Merced 95343, CA, USA
| | - Carlos Ayestarán Latorre
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
- The Thomas Young Centre, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
| | - Ashlie Martini
- Department of Mechanical Engineering, University of California-Merced, 5200 N. Lake Road, Merced 95343, CA, USA
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
- The Thomas Young Centre, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK
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5
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Thoms E, Napolitano S. Enthalpy-entropy compensation in the slow Arrhenius process. J Chem Phys 2023; 159:161103. [PMID: 37888759 DOI: 10.1063/5.0174213] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/02/2023] [Indexed: 10/28/2023] Open
Abstract
The Meyer-Neldel compensation law, observed in a wide variety of chemical reactions and other thermally activated processes, provides a proportionality between the entropic and the enthalpic components of an energy barrier. By analyzing 31 different polymer systems, we show that such an intriguing behavior is encountered also in the slow Arrhenius process, a recently discovered microscopic relaxation mode, responsible for several equilibration mechanisms both in the liquid and the glassy state. We interpret this behavior in terms of the multiexcitation entropy model, indicating that overcoming large energy barriers can require a high number of low-energy local excitations, providing a multiphonon relaxation process.
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Affiliation(s)
- Erik Thoms
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université libre de Bruxelles (ULB), Brussels 1050, Belgium
| | - Simone Napolitano
- Laboratory of Polymer and Soft Matter Dynamics, Experimental Soft Matter and Thermal Physics (EST), Université libre de Bruxelles (ULB), Brussels 1050, Belgium
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6
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Hotta M, Zushi Y, Iwasaki S, Fukunaga S, Koga N. Efflorescence kinetics of sodium carbonate decahydrate: a universal description as a function of temperature, degree of reaction, and water vapor pressure. Phys Chem Chem Phys 2023; 25:27114-27130. [PMID: 37815046 DOI: 10.1039/d3cp04000c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The efflorescence of sodium carbonate decahydrate (SC-DH) required to form its monohydrate (SC-MH) was systematically studied under isothermal and linear nonisothermal conditions at different atmospheric water vapor pressures (p(H2O)) using a humidity-controlled thermogravimetry instrument equipped with a cooling circulator. The universal kinetic description at various temperatures (T) and p(H2O) values was evaluated using the extended kinetic equation with an accommodation function (AF) comprising p(H2O) and the equilibrium pressure of the reaction (Peq(T)). By optimizing two exponents in the AF, all kinetic data were universally described in terms of the isoconversional kinetic relationship examined at individual degrees of reaction (α). This enabled the examination of the isothermal kinetic relationship and the parameterization of the contribution of the self-generated water vapor, allowing the incorporation of kinetic data recorded in a stream of dry N2 into the universal kinetic description as a function of T, α, and p(H2O). The results indicated that the reaction is physico-geometrically controlled by the surface reaction at the hemispherical top surface of SC-DH particles and subsequent advancement of the reaction interface toward the center and bottom of these particles, where the interfacial process is regulated by an elementary step of the consumption of H2O vacancies to form the SC-MH building unit. The apparent activation energy (Ea) of ∼178 kJ mol-1 was determined using the extended kinetic approach considering the effect of p(H2O) correlated with the intrinsic Ea of the Arrhenius-type temperature dependence (∼63 kJ mol-1) by subtracting the contribution of the temperature dependence of Peq(T) in the AF.
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Affiliation(s)
- Mito Hotta
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Yuto Zushi
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Shun Iwasaki
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Shunsuke Fukunaga
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Nobuyoshi Koga
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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7
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Harrison ARP, Kwong KY, Zheng Y, Balkrishna A, Dyson A, Marek EJ. Kinetic and Thermodynamic Enhancement of Low-Temperature Oxygen Release from Strontium Ferrite Perovskites Modified with Ag and CeO 2. ENERGY & FUELS : AN AMERICAN CHEMICAL SOCIETY JOURNAL 2023; 37:9487-9499. [PMID: 37435585 PMCID: PMC10331733 DOI: 10.1021/acs.energyfuels.3c01263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 05/31/2023] [Indexed: 07/13/2023]
Abstract
The redox behavior of the nonstoichiometric perovskite oxide SrFeO3-δ modified with Ag, CeO2, and Ce was assessed for chemical looping air separation (CLAS) via thermogravimetric analysis and by cyclic release and uptake of O2 in a packed bed reactor. The results demonstrated that the addition of ∼15 wt % Ag at the surface of SrFeO3-δ lowers the temperature of oxygen release in N2 by ∼60 °C (i.e., from 370 °C for bare SrFeO3-δ to 310 °C) and more than triples the amount of oxygen released per CLAS cycle at 500 °C. Impregnation of SrFeO3-δ with Ag increased the concentration of oxygen vacancies at equilibrium, lowering (3 - δ) under all investigated oxygen partial pressures. The addition of CeO2 at the surface or into the bulk of SrFeO3-δ resulted in more modest changes, with a decrease in temperature for O2 release of 20-25 °C as compared to SrFeO3-δ and a moderate increase in oxygen yield per reduction cycle. The apparent kinetic parameters for reduction of SrFeO3-δ, with Ag and CeO2 additives, were determined from the CLAS experiments in a packed bed reactor, giving activation energies and pre-exponential factors of Ea,reduction = 66.3 kJ mol-1 and Areduction = 152 mol s-1 m-3 Pa-1 for SrFeO3-δ impregnated with 10.7 wt % CeO2, 75.7 kJ mol-1 and 623 molO2 s-1 m -3 Pa-1 for SrFeO3-δ mixed with 2.5 wt % CeO2 in the bulk, 29.9 kJ mol-1 and 0.88 molO2 s-1 m-3 Pa-1 for Sr0.95Ce0.05FeO3-δ, and 69.0 kJ mol-1 and 278 molO2 s-1 m-3 Pa-1 for SrFeO3-δ impregnated with 12.7 wt % Ag, respectively. Kinetics for reoxidation were much faster and were assessed for two materials with the slowest oxygen uptake, SrFeO3-δ, giving the activation energy Ea,oxidation = 177.1 kJ mol-1 and pre-exponential factor Aoxidation = 3.40 × 1010 molO2 s-1 m-3 Pa-1, and Sr0.95Ce0.05FeO3-δ, giving the activation energy Ea,oxidation = 64.0 kJ mol-1, and pre-exponential factor Aoxidation = 584 molO2 s-1 m-3 Pa-1.
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Affiliation(s)
- Alexander R. P. Harrison
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, U.K.
| | - Kien Y. Kwong
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, U.K.
| | - Yaoyao Zheng
- Department
of Engineering, University of Cambridge, Trumpington Street, CB2 1PZ Cambridge, U.K.
| | - Abhishek Balkrishna
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, U.K.
| | - Alice Dyson
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, U.K.
| | - Ewa J. Marek
- Department
of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, U.K.
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8
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Baklanov AV, Kiselev VG. The Nature of the Enthalpy-Entropy Compensation and "Exotic" Arrhenius Parameters in the Denaturation Kinetics of Proteins. Int J Mol Sci 2023; 24:10630. [PMID: 37445807 DOI: 10.3390/ijms241310630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/13/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
Protein unfolding is a ubiquitous process responsible for the loss of protein functionality (denaturation), which, in turn, can be accompanied by the death of cells and organisms. The nature of enthalpy-entropy compensation (EEC) in the kinetics of protein unfolding is a subject of debate. In order to investigate the nature of EEC, the "completely loose" transition state (TS) model has been applied to calculate the Arrhenius parameters for the unfolding of polyglycine dimers as a model process. The calculated Arrhenius parameters increase with increasing dimer length and demonstrate enthalpy-entropy compensation. It is shown that EEC results from the linear correlations of enthalpy and entropy of activation with dimer length, which are derived directly from the properties of the transition state. It is shown that EEC in solvated (hydrated, etc.) proteins is a direct consequence of EEC in proteins themselves. The suggested model allows us also to reproduce and explain "exotic" very high values of the pre-exponential factor measured for the proteins unfolding, which are drastically higher than those known for unimolecular reactions of organic molecules. A similar approach can be applied to analyzing the nature of EEC phenomena observed in other areas of chemistry.
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Affiliation(s)
- Alexey V Baklanov
- Institute of Chemical Kinetics and Combustion SB RAS, 3 Institutskaya Street, 630090 Novosibirsk, Russia
| | - Vitaly G Kiselev
- Institute of Chemical Kinetics and Combustion SB RAS, 3 Institutskaya Street, 630090 Novosibirsk, Russia
- Department of Physics, Novosibirsk State University, 1 Pirogova Street, 630090 Novosibirsk, Russia
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9
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Lyon RE. A Physical Basis for Kinetic Compensation. J Phys Chem A 2023; 127:2399-2406. [PMID: 36867752 DOI: 10.1021/acs.jpca.2c07715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Kinetic compensation is a strong, positive correlation between the Arrhenius activation energy E and the frequency factor A for a reaction between the same reactants under similar experimental conditions or similar reactants under the same conditions, even though these parameters are supposed to be independent. The kinetic compensation effect (KCE) is demonstrated by a linear relationship between ln[A] and E/R in the eponymous Constable plot and has been the subject of more than 50 000 publications over the past 100 years, with no consensus opinion about the cause of this effect. In this paper, it is suggested that the linear relationship between ln[A] and E is the result of a real or spurious path dependence of the reaction history between the initial state of the pure reactant(s) and the final state of the pure product(s) having standard enthalpy and entropy differences, ΔH° and ΔS°, respectively. The single-step rate law approximation of a reversible reaction leads to T0 = H°/ΔS° as the dynamic thermal (thermodynamic) equilibrium temperature and 1/T0 = (ln[A̅/k0])/(E̅/R) as the slope of a Constable/KCE plot or the crossover temperature of Arrhenius lines in an isokinetic relationship (IKR), where A̅ and E̅ are mean values for the ensemble of compensating {Ei, Ai} pairs and k0 is a constant that accounts for the path dependence of the reaction history and reconciles the KCE with the IKR. This proposed physical basis for the KCE and IKR is supported by qualitative agreement between ΔH° and ΔS° calculated from the statistics of compensating {Ei, Ai} pairs in the literature, and the difference in the standard enthalpies and entropies of formation of the products and reactants for thermal decomposition of organic peroxides, calcium carbonate, and poly(methyl methacrylate).
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Affiliation(s)
- Richard E Lyon
- Aviation Research Division, Federal Aviation Administration W. J. Hughes Technical Center, Atlantic City International Airport, Egg Harbor Township, New Jersey 08405, United States
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10
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How many data points and how large an R-squared value is essential for Arrhenius plots? J Catal 2023. [DOI: 10.1016/j.jcat.2023.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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11
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Zushi Y, Iwasaki S, Koga N. Effect of atmospheric water vapor on independent-parallel thermal dehydration of a compacted composite of an inorganic hydrate: sodium carbonate monohydrate grains comprising crystalline particles and a matrix. Phys Chem Chem Phys 2022; 24:29827-29840. [PMID: 36468312 DOI: 10.1039/d2cp04699g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effect of atmospheric water vapor on the thermal dehydration of sodium carbonate monohydrate (SC-MH), which was characterized as cubic grains of a compacted composite comprising columnar SC-MH crystals and a matrix, was systematically assessed using a humidity-controlled thermogravimetry system at various atmospheric water vapor pressures (p(H2O)). The thermal dehydration of the SC-MH compacted composite occurred via an induction period (IP) and partially overlapping two-step mass loss steps due to the thermal dehydration of the SC-MH matrix and columnar crystals. All component reaction steps were retarded with an increase in the p(H2O) value. The kinetics of individual reaction steps were universally described over different temperatures and p(H2O) values based on a kinetic equation that considered p(H2O) and the equilibrium pressure of the thermal dehydration. Additionally, the physico-geometrical consecutive surface reaction (SR) and subsequent phase boundary-controlled reaction (PBR) model was employed to describe the first mass loss step. The difference between the effects of atmospheric p(H2O) on SR and PBR processes was parameterized via an advanced kinetic analysis. The kinetic behavior of the second mass loss step was discussed based on a three-dimensional contracting geometry model with accelerating reaction interface advancement, where the changes in the rate behavior with atmospheric p(H2O) were explained by the total effect of atmospheric and self-generated p(H2O) on the kinetics. The present results provide additional insights into the independent-parallel thermal decomposition kinetics of composite materials by considering the effects of atmospheric and self-generated gases.
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Affiliation(s)
- Yuto Zushi
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Shun Iwasaki
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Nobuyoshi Koga
- Department of Science Education, Division of Educational Sciences, Graduate School of Humanities and Social Sciences, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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12
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Benhammada A, Trache D, Chelouche S. Catalytic effect investigation of α-Fe2O3 and α-Fe2O3-CMS nanocomposites on the thermal behavior of NC/DGEDN mixture: DSC measurements and kinetic modeling. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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13
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Lease N, Klamborowski LM, Perriot R, Cawkwell MJ, Manner VW. Identifying the Molecular Properties that Drive Explosive Sensitivity in a Series of Nitrate Esters. J Phys Chem Lett 2022; 13:9422-9428. [PMID: 36191261 PMCID: PMC9575148 DOI: 10.1021/acs.jpclett.2c02701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Energetic materials undergo hundreds of chemical reactions during exothermic runaway, generally beginning with the breaking of the weakest chemical bond, the "trigger linkage." Herein we report the syntheses of a series of pentaerythritol tetranitrate (PETN) derivatives in which the energetic nitrate ester groups are systematically substituted by hydroxyl groups. Because all the PETN derivatives have the same nitrate ester-based trigger linkages, quantum molecular dynamics (QMD) simulations show very similar Arrhenius kinetics for the first reactions. However, handling sensitivity testing conducted using drop weight impact indicates that sensitivity decreases precipitously as nitrate esters are replaced by hydroxyl groups. These experimental results are supported by QMD simulations that show systematic decreases in the final temperatures of the products and the energy release as the nitrate ester functional groups are removed. To better interpret these results, we derive a simple model based only on the specific enthalpy of explosion and the kinetics of trigger linkage rupture that accounts qualitatively for the decrease in sensitivity as nitrate ester groups are removed.
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Affiliation(s)
- Nicholas Lease
- High
Explosives Science & Technology, Los
Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Lisa M. Klamborowski
- High
Explosives Science & Technology, Los
Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Romain Perriot
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Marc J. Cawkwell
- Theoretical
Division, Los Alamos National Laboratory, Los Alamos, New Mexico87545, United States
| | - Virginia W. Manner
- High
Explosives Science & Technology, Los
Alamos National Laboratory, Los Alamos, New Mexico87545, United States
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14
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Marangwanda GT, Madyira DM, Chihobo CH. Determination of Cocombustion Kinetic Parameters for Bituminous Coal and Pinus Sawdust Blends. ACS OMEGA 2022; 7:32108-32118. [PMID: 36120035 PMCID: PMC9476186 DOI: 10.1021/acsomega.2c03342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Cocombustion of bituminous coal (HC) and Pinus sawdust (PS) was investigated in this paper with the aim of determining the kinetic parameters relevant to cocombustion reactions of their fuel blends. PS was used because it is a waste biomass product capable of generating energy. Motivated by the need to partly substitute HC used in existing boilers with PS, the optimum kinetic parameters at different blending ratios were thus investigated with the ultimate goal of diversifying the energy portfolio for these boilers. Blended samples were prepared with a PS substitution by mass ranging from 0 to 30%, thus producing five samples, namely:100HC, 90HC10PS, 80HC20PS, 70HC30PS, and 100PS. A simultaneous thermogravimetric analyzer was used to investigate the degradation of the fuel samples under a synthetic air atmosphere using 5, 12.5, and 20 °C/min heating rates. The kinetic parameters were evaluated using the distributed activation energy model (DAEM) due to its ability to evaluate complex parallel chemical mechanisms. The influential homogenous volatile combustion and heterogenous combustion stages produced an increasing trend for activation energy (E a) with increased PS (100HC to 70HC30PS) from an average of 61.80-104.34 kJ/mol while the pre-exponential factor increased from 1.31 × 105 to 6.52 × 108. Generally, blending of HC with PS did not produce a linear variation of the kinetic parameters; thus, by using various plots, an optimum blending ratio of 80HC20PS was deduced.
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Affiliation(s)
- Garikai T. Marangwanda
- Department
of Mechanical Engineering Science, University
of Johannesburg, Johannesburg 2006, South Africa
- Department
of Fuels and Energy Engineering, School of Engineering Sciences and
Technologies, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
| | - Daniel M. Madyira
- Department
of Mechanical Engineering Science, University
of Johannesburg, Johannesburg 2006, South Africa
| | - Chido H. Chihobo
- Department
of Fuels and Energy Engineering, School of Engineering Sciences and
Technologies, Chinhoyi University of Technology, Chinhoyi, Zimbabwe
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15
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Ai S, Qin Y, Hong Y, Liu L, Yu W. Removal of C3–C4 diols in ethylene glycol via selective dehydration reactions over Beta zeolite with acidity tailored. J Catal 2022. [DOI: 10.1016/j.jcat.2022.07.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Šimon P, Dubaj T, Cibulková Z. Frequent flaws encountered in the manuscripts of kinetic papers. JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY 2022; 147:10083-10088. [PMID: 35813001 PMCID: PMC9252552 DOI: 10.1007/s10973-022-11436-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
In the manuscripts dealing with thermoanalytical kinetics, many flaws, mistakes, and misconceptions are encountered repeatedly. In this paper, frequent flaws encountered in manuscript of kinetic papers are reviewed, mainly those originating in the false interpretation of the general rate equation, improper employment of integral isoconversional methods, conclusions drawn from the values of a single kinetic parameter, absence of error estimation and application of single-heating rate methods. Assessment of the quality of kinetic treatment is also noticed. Some experimental imperfections that could lead to incorrect values of kinetic parameters are mentioned.
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Affiliation(s)
- Peter Šimon
- Present Address: Faculty of Chemical and Food Technology, Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia
| | - Tibor Dubaj
- Present Address: Faculty of Chemical and Food Technology, Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia
| | - Zuzana Cibulková
- Present Address: Faculty of Chemical and Food Technology, Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia
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17
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Biochar Synthesis from Mineral- and Ash-Rich Waste Biomass, Part 1: Investigation of Thermal Decomposition Mechanism during Slow Pyrolysis. MATERIALS 2022; 15:ma15124130. [PMID: 35744189 PMCID: PMC9227128 DOI: 10.3390/ma15124130] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/19/2022] [Accepted: 06/07/2022] [Indexed: 02/04/2023]
Abstract
Synthesizing biochar from mineral- and ash-rich waste biomass (MWB), a by-product of human activities in urban areas, can result in renewable and versatile multi-functional materials, which can also cater to the need of solid waste management. Hybridizing biochar with minerals, silicates, and metals is widely investigated to improve parent functionalities. MWB intrinsically possesses such foreign materials. The pyrolysis of such MWB is kinetically complex and requires detailed investigation. Using TGA-FTIR, this study investigates and compares the kinetics and decomposition mechanism during pyrolysis of three types of MWB: (i) mineral-rich banana peduncle (BP), (ii) ash-rich sewage sludge (SS), and (iii) mineral and ash-rich anaerobic digestate (AD). The results show that the pyrolysis of BP, SS, and AD is exothermic, catalyzed by its mineral content, with heat of pyrolysis 5480, 4066, and 1286 kJ/kg, respectively. The pyrolysis favors char formation kinetics mainly releasing CO2 and H2O. The secondary tar reactions initiate from ≈318 °C (BP), 481 °C (SS), and 376 °C (AD). Moreover, negative apparent activation energies are intrinsic to their kinetics after 313 °C (BP), 448 °C (SS), and 339 °C (AD). The results can support in tailoring and controlling sustainable biochar synthesis from slow pyrolysis of MWB.
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18
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Chakraborty M, Dey A, Bhattacharjee A. Insights into the thermal decomposition of organometallic compound ferrocene carboxaldehyde as precursor for hematite nanoparticles synthesis. Z PHYS CHEM 2022. [DOI: 10.1515/zpch-2021-3175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The paper deals with the thermal decomposition of organometallic compound ferrocene carboxaldehyde [(C5H4CHO)Fe(C5H5)] in oxidative atmosphere, which leads to pure hematite nanoparticles, studied with non-isothermal thermogravimetry (TG) protocol. Deconvolution method with Fraser-Suzuki fit function is adopted to resolve the complex multistep TG profiles into six different reaction steps. Step-wise reaction kinetic parameters (activation energy, reaction mechanism function, reaction rate) are estimated based on the mathematical analysis of the multi-heating rate TG data primarily following model-free (integral isoconversional) approach and using master-plot method. The estimated kinetic parameters are utilised to reconstruct the conversion plots which successfully resemble the experimentally observed ones. A plausible reaction process leading to hematite on thermal decomposition of ferrocene carboxaldehyde as the end product is discussed. A comparative discussion on the thermal decomposition of two ferrocene derivatives have been made. The novelty of the present work lies in successful deconvolution of complex TG profiles and hence obtaining the step-wise reaction kinetic parameters demonstrating different reaction mechanisms involved in the thermal synthesis of hematite nanoparticles starting from ferrocene carboxaldehyde which have no prior reporting. Further, a satisfactory agreement between the reconstructed and experimental decomposition profiles establishes the correctness of the applied modelling approach as well as the methodology adopted.
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Affiliation(s)
- Manisha Chakraborty
- Department of Physics , Institute of Science, Visva-Bharati University , Santiniketan , 731235 , India
| | - Anubha Dey
- Department of Physics , Institute of Science, Visva-Bharati University , Santiniketan , 731235 , India
| | - Ashis Bhattacharjee
- Department of Physics , Institute of Science, Visva-Bharati University , Santiniketan , 731235 , India
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19
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Jena MK, Kumar V, Liu S, Vuthaluru H. Steam gasification of low-rank coal chars: Insights into the kinetic compensation effects and physical significance of kinetic parameters. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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20
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Explanation of the Compensation Law and the Isokinetic Point in the Electrical Conduction of Crosslinked Polyethylene. INT J POLYM SCI 2022. [DOI: 10.1155/2022/7060337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Thermally activated direct current (DC) electrical conductivity in low-density polyethylene (LDPE) is known to be subject to the compensation law. Accordingly, the preexponential factor follows a specific relation with activation energy, reducing overall changes in conductivity. This relationship is governed by the Meyer-Neldel temperature. However, there is no published evidence for a corresponding isokinetic point, a temperature where the conductivity of all LDPE samples is the same. Here, it is determined that the compensation law applies to both DC and alternating current (AC) conduction for LDPE and for crosslinked polyethylene (XLPE) without an observed isokinetic point. The potential origins of compensation in polyethylene are discussed as well as reasons for similarity between LDPE and XLPE. It is observed that prolonged water exposure removed the compensation behavior. Meanwhile, preheating samples in the oven prior to measurements modifies the compensation behavior and reduced the spread around the isokinetic point. It is thus deduced that an isokinetic point can be observed in polyethylene but is obscured by contributions from water and other impurities.
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Iwasaki S, Zushi Y, Koga N. Advanced kinetic approach to the multistep thermal dehydration of calcium sulfate dihydrate under different heating and water vapor conditions: kinetic deconvolution and universal isoconversional analyses. Phys Chem Chem Phys 2022; 24:9492-9508. [DOI: 10.1039/d2cp00640e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study aims to identify the kinetic features of individual reaction steps of the multistep thermal dehydration of calcium sulfate dihydrate (CS-DH) to anhydride via hemihydrate (CS-HH) intermediate by achieving...
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22
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Okazaki T, Hara M, Muravyev NV, Koga N. Thermally induced dehydration reactions of monosodium L-glutamate monohydrate: dehydration of solids accompanied by liquefaction. Phys Chem Chem Phys 2021; 24:129-141. [PMID: 34901979 DOI: 10.1039/d1cp04734e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we investigated the mechanistic features and kinetics of the thermal decomposition of solids accompanied by liquefaction as exemplified by the thermal dehydration reactions of monosodium L-glutamate monohydrate (MSG-MH). The thermal dehydration of MSG-MH occurs via two mass-loss processes comprising the elimination of crystalline water and intramolecular dehydration. Multistep kinetic behaviors and the liquefaction during both thermal dehydration processes were evidenced by systematic thermoanalytical measurements and in situ microscopic observations. During the thermal dehydration of crystalline water, the liquefaction of the surface product layer occurred midway through the reaction, and the subsequent reaction proceeded with a geometrical constraint, where the solid reactant was covered by a liquid surface layer, affording a solid anhydride. The intramolecular dehydration of the solid anhydride yielded a liquid product on the surface of the reacting particles, and the internal solid reactant dissolved in the liquid product. Subsequently, the intramolecular dehydration proceeded in the liquid phase to afford liquid sodium pyroglutamate. The net kinetic behavior of the physico-geometrical reaction steps in each thermal dehydration process was revealed using kinetic approaches based on cumulative and conjunct kinetic equations. The advanced kinetic approaches employed to reveal the specific kinetic features of the heterogeneous reaction processes in solid-liquid-gas systems are described in this article.
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Affiliation(s)
- Takahiro Okazaki
- Department of Science Education, Division of Educational Sciences, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Masami Hara
- Department of Science Education, Division of Educational Sciences, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Nikita V Muravyev
- Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin Str., 119991, Moscow, Russia
| | - Nobuyoshi Koga
- Department of Science Education, Division of Educational Sciences, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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23
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Ayestarán Latorre C, Remias JE, Moore JD, Spikes HA, Dini D, Ewen JP. Mechanochemistry of phosphate esters confined between sliding iron surfaces. Commun Chem 2021; 4:178. [PMID: 36697879 PMCID: PMC9814736 DOI: 10.1038/s42004-021-00615-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 11/26/2021] [Indexed: 01/28/2023] Open
Abstract
The molecular structure of lubricant additives controls not only their adsorption and dissociation behaviour at the nanoscale, but also their ability to reduce friction and wear at the macroscale. Here, we show using nonequilibrium molecular dynamics simulations with a reactive force field that tri(s-butyl)phosphate dissociates much faster than tri(n-butyl)phosphate when heated and compressed between sliding iron surfaces. For both molecules, dissociative chemisorption proceeds through cleavage of carbon-oxygen bonds. The dissociation rate increases exponentially with temperature and stress. When the rate-temperature-stress data are fitted with the Bell model, both molecules have similar activation energies and activation volumes and the higher reactivity of tri(s-butyl)phosphate is due to a larger pre-exponential factor. These observations are consistent with experiments using the antiwear additive zinc dialkyldithiophosphate. This study represents a crucial step towards the virtual screening of lubricant additives with different substituents to optimise tribological performance.
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Affiliation(s)
- Carlos Ayestarán Latorre
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
- Department of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | | | - Joshua D Moore
- Afton Chemical Corporation, Richmond, VA, 23219, USA
- Dassault Systèmes Americas Corporation, Waltham, MA, 02451, USA
| | - Hugh A Spikes
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Daniele Dini
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - James P Ewen
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
- Institute of Molecular Science and Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
- Thomas Young Centre for the Theory and Simulation of Materials, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
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24
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Zhang L, Yue Q, Yang H. Kinetics and mechanism of non-isothermal oxidation for FeO–SiO2–CaO ternary copper slag system. REACTION KINETICS MECHANISMS AND CATALYSIS 2021. [DOI: 10.1007/s11144-021-02119-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Perez-Benito JF, Clavero-Masana A. Interdependence of the Hammett and isokinetic relationships: a numerical simulation approach. MONATSHEFTE FUR CHEMIE 2021. [DOI: 10.1007/s00706-021-02804-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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26
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Griessen R, Dam B. Simple Accurate Verification of Enthalpy-Entropy Compensation and Isoequilibrium Relationship. Chemphyschem 2021; 22:1774-1784. [PMID: 34213060 PMCID: PMC8456872 DOI: 10.1002/cphc.202100431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 06/30/2021] [Indexed: 11/16/2022]
Abstract
In many experimental investigations of thermodynamic equilibrium or kinetic properties of series of similar reactions it is found that the enthalpies and entropies derived from Van ′t Hoff or Arrhenius plots exhibit a strong linear correlation. The origin of this Enthalpy‐Entropy compensation, which is strongly related to the coalescence tendency of Van ′t Hoff or Arrhenius plots, is not necessarily due to a physical/chemical/biological process. It can also be a merely statistical artefact. A new method, called Combined K‐CQF makes it possible both to quantify the degree of coalescence of experimental Van ‘t Hoff lines and to verify whether or not the Enthalpy‐Entropy Compensation is of a statistical origin at a desired confidence level. The method is universal and can handle data sets with any degree of coalescence of Van ‘t Hoff (or Arrhenius) plots. The new method requires only a standard least square fit of the enthalpyΔH versus entropy ΔS plot to determine the two essential dimensionless parameters K and CQF. The parameter K indicates the position (in inverse temperature) of the coalescence region of Van ‘t Hoff plots and CQF is a quantitative measure of the smallest spread of the Van ‘t Hoff plots. The position of the (K, CQF) couple with respect to universal confidence contours determined from a large number of simulations of random Van ‘t Hoff plots indicates straightforwardly whether or not the ΔH‐ΔS compensation is a statistical artefact.
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Affiliation(s)
- Ronald Griessen
- Condensed Matter Physics, Faculty of Sciences, VU University Amsterdam, De Boelelaan, 1081, 1081 HV, Amsterdam, The, Netherlands
| | - Bernard Dam
- Materials for Energy Conversion and Storage, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The, Netherlands
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27
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Onwumelu C, Nordeng SH, Nwachukwu FC, Adeyilola A. Combining Source Rock Kinetics and Vitrinite Reflectance in Source Rock Evaluation of the Bakken Formation, Williston Basin, USA. ACS OMEGA 2021; 6:10679-10690. [PMID: 34056221 PMCID: PMC8153773 DOI: 10.1021/acsomega.1c00048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/17/2021] [Indexed: 06/12/2023]
Abstract
The elements of Bakken Petroleum System consist of two source rocks with high underlying burial depths for significant hydrocarbon generation. However, this deep hydrocarbon generation process is dependent on its kinetic properties, thermal maturity, and geochemical properties. The statistical compensation effect is a complicating factor in the kinetic analyses of the Bakken Formation. In this study, we experimentally determined the kinetics of the Bakken formation source beds, observed the presence of the residual compensation effect, and numerically established a correlation between the kinetic parameters, thermal maturity indices (T max), and the vitrinite reflectance (VRo) and bitumen reflectance (BRo). First, we conducted source rock analysis to determine kinetic properties and the organic geochemical assays of reactive kerogen in the Bakken source beds. Finally, we incorporated previous established studies to generate numerical correlation for T max in terms of VRo and BRo reflectance. Our kinetic results show evidence of the residual compensation effect in the Bakken Formation when samples are repeatedly analyzed. The simultaneous linear expression of the residual compensation effect and the regression analysis of the solutions to the Kissinger equation for heating rate, yielded a kinetic parameter solution that correlates with T max. Furthermore, recalculated T max values established a correlation between the kinetic parameters, T max, VRo, and BRo. The application of state-of-the-art numerical correlations to measure subsurface kinetics, source rock richness, and burial-depth temperatures will enhance the accuracy of reservoir exploration and hydrocarbon production within the Bakken Formation.
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Affiliation(s)
- Chioma Onwumelu
- Harold
Hamm School of Geology and Geological Engineering, University of North
Dakota, Grand
Forks North Dakota 58202, United States
| | - Stephan H. Nordeng
- Harold
Hamm School of Geology and Geological Engineering, University of North
Dakota, Grand
Forks North Dakota 58202, United States
| | - Francis C. Nwachukwu
- Harold
Hamm School of Geology and Geological Engineering, University of North
Dakota, Grand
Forks North Dakota 58202, United States
| | - Adedoyin Adeyilola
- Department
of Earth and Atmospheric Sciences, Central
Michigan University, Mount
Pleasant Michigan 48859, United States
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28
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Bessa W, Trache D, Derradji M, Bentoumia B, Tarchoun AF, Hemmouche L. Effect of silane modified microcrystalline cellulose on the curing kinetics, thermo-mechanical properties and thermal degradation of benzoxazine resin. Int J Biol Macromol 2021; 180:194-202. [PMID: 33737176 DOI: 10.1016/j.ijbiomac.2021.03.080] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/11/2021] [Accepted: 03/13/2021] [Indexed: 10/21/2022]
Abstract
In the frame of developing sustainable, eco-friendly and high performance materials, microcrystalline cellulose modified through silane coupling agent (MCC Si) is used as a reinforcing agent of benzoxazine resin to manufacture composites at different loadings of 5, 10, 15, 20 wt%. The structural, morphological and crystallinity characterizations of the modified MCC were initially performed to scrutinize the changes and confirm the modification. Then, an investigation on the crosslinking process of the prepared composites was held through curing kinetic study employing isoconversional methods. The kinetic data revealed a decrease in the average values of activation energy and the pre-exponential factor, particularly for composite supplemented with 10% MCC Si, whereas all samples disclosed a tendency of an autocatalytic curing mechanism. Furthermore, the study of the dynamic mechanical properties and degradation features of the cured specimens, respectively, indicated a superior stiffness attributable to the good interaction between BA-a and MCC Si, and enhanced thermal stability for the composites compared to pristine resin.
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Affiliation(s)
- Wissam Bessa
- Energetic Materials Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria
| | - Djalal Trache
- Energetic Materials Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria.
| | - Mehdi Derradji
- Process Engineering Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria
| | - Benaouda Bentoumia
- Energetic Materials Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria
| | - Ahmed Fouzi Tarchoun
- Energetic Materials Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria; Energetic Propulsion Laboratory, Teaching and Research Unit of Energetic Processes, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria
| | - Larbi Hemmouche
- Materials Engineering Laboratory, Ecole Militaire Polytechnique, BP 17, Bordj El-Bahri, 16046 Algiers, Algeria
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29
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Rizk SA, El-Hashash MA, Youssef AA, Elgendy AT. A green microwave method for synthesizing a more stable phthalazin-1-ol isomer as a good anticancer reagent using chemical plasma organic reactions. Heliyon 2021; 7:e06220. [PMID: 33748447 PMCID: PMC7969343 DOI: 10.1016/j.heliyon.2021.e06220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 11/24/2020] [Accepted: 02/04/2021] [Indexed: 01/11/2023] Open
Abstract
Conventional synthesis of the phthalazine has already allowed affording the phthalazin-1-one phthalazin-1-ol dynamic equilibrium that decreases the anticancer activity due to diminishing the concentration of the phthalazin-1-ol product. Nowadays, pure phthalazin-1-ol (5) can be gaining by using green microwave tools that increase the power of the phthalazine nucleus as an anticancer drug. A microscopic thermal kinetic parameter like activation energy and the pre-exponential factor of the chemical plasma organic reactions affording pure phthalazin-1-ol (5) is calculated by using DFT simulation is obtained. Then we fed these parameters into the exact Arrhenius model to evaluate the distribution of chemical equilibrium conditions for producing phthalazin-1-ol. The proposed novel models that matching between microscopic and macroscopic show that the thermal stability of the equivalent temperature of phthalazin-1-ol is more stable than phthalazinone-1-one (4) in case of using plasma organic effect (green microwave) at 485 K. The structures of the prepared compounds were explained by physical and spectral data like FT-IR, 1H-NMR. Moreover, the theoretical calculations of Gibbs entropy of the phase transfer confirmed the equilibrium state of phthalazin-1-ol with the experimental result is achieved. Briefly, we introduce a good study for obtaining more stable phthalazin-1-ol isomer by using a green microwave method which is considered as good anticancer reagents of phenolic group (OH) and p-propenyl-anisole precursor as anise oil analogous.
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Affiliation(s)
- Sameh A. Rizk
- Organic Chemistry, Chemistry Department, Science Faculty, Ain-Shams University, Egypt
| | - Maher A. El-Hashash
- Organic Chemistry, Chemistry Department, Science Faculty, Ain-Shams University, Egypt
| | - Amr A. Youssef
- Mathematic Department, Science Department, Ain-Shams University, 11566, Cairo, Egypt
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30
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Li X, Yang Y, Song C, Sun Y, Han Y, Zhao Y, Wang J. Fabrication and Characterization of Viton@FOX-7@Al Spherical Composite with Improved Thermal Decomposition Property and Safety Performance. MATERIALS (BASEL, SWITZERLAND) 2021; 14:1093. [PMID: 33652811 PMCID: PMC7956709 DOI: 10.3390/ma14051093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/05/2021] [Accepted: 02/11/2021] [Indexed: 11/28/2022]
Abstract
To achieve a uniform distribution of the components and a better performance of aluminized composite explosives, Viton (dipolymers of hexafluoropropylene and vinylidene fluoride) @ FOX-7 (1,1-diamino-2,2-dinitroethylene) @Al microspheres and FOX-7/Viton@Al were synthesized by spray-drying strategy contrastively. Viton@FOX-7@Al owned porous and loose morphology and good sphericity with a retained crystal phase of FOX-7 and aluminum. The 23.56% fluorine content on Viton@FOX-7@Al surface indicated that Viton was completely coated on the surface of the particles. Nanosized aluminum (nAl) in Viton@FOX-7@Al had a certain catalytic activity on the thermal decomposition process of FOX-7 resulting in a depressed exothermic peak temperature and reduced apparent activation energy relative to nAl in FOX-7/Viton@Al. Because of the specific structure and the synergies between each individual component, Viton@FOX-7@Al showed reduced impact sensitivity and friction sensitivity than those of FOX-7/Viton@Al. In brief, Viton@FOX-7@Al with multilevel coating structure possessed comparatively low thermal decomposition energy requirement and improved safety performance.
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Affiliation(s)
- Xiaodong Li
- School of Environment and Safety Engineering, North University of China, Jiancaoping District, Taiyuan 030051, China; (C.S.); (Y.S.); (Y.H.); (Y.Z.); (J.W.)
| | - Yue Yang
- School of Environment and Safety Engineering, North University of China, Jiancaoping District, Taiyuan 030051, China; (C.S.); (Y.S.); (Y.H.); (Y.Z.); (J.W.)
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31
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Jelić D. Thermal Stability of Amorphous Solid Dispersions. Molecules 2021; 26:E238. [PMID: 33466393 PMCID: PMC7795217 DOI: 10.3390/molecules26010238] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/25/2020] [Accepted: 12/29/2020] [Indexed: 11/24/2022] Open
Abstract
Amorphous solid dispersion drug delivery systems (ASD DDS) were proved to be efficient for the enhancement of solubility and bioavailability of poorly water-soluble drugs. One of the major keys for successful preparation of ASD is the selection of appropriate excipients, mostly polymers, which have a crucial role in improving drug solubility and its physical stability. Even though, excipients should be chemically inert, there is some evidence that polymers can affect the thermal stability of active pharmaceutical ingredients (API). The thermal stability of a drug is closely related to the shelf-life of pharmaceutical products and therefore it is a matter of high pharmaceutical relevance. An overview of thermal stability of amorphous solids is provided in this paper. Evaluation of thermal stability of amorphous solid dispersion is perceived from the physicochemical perspective, from a kinetic (motions) and thermodynamic (energy) point of view, focusing on activation energy and fragility, as well all other relevant parameters for ASD design, with a glance on computational kinetic analysis of solid-state decomposition.
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Affiliation(s)
- Dijana Jelić
- Chemistry Department, Faculty of Natural Sciences and Mathematics, University of Banja Luka, dr Mladena Stojanovića 2a, 78 000 Banja Luka, Bosnia and Herzegovina
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32
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Characterization of raw and treated Arundo donax L. cellulosic fibers and their effect on the curing kinetics of bisphenol A-based benzoxazine. Int J Biol Macromol 2020; 164:2931-2943. [DOI: 10.1016/j.ijbiomac.2020.08.179] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/19/2020] [Accepted: 08/22/2020] [Indexed: 11/21/2022]
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33
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Vasudev V, Ku X, Lin J. Pyrolysis of algal biomass: Determination of the kinetic triplet and thermodynamic analysis. BIORESOURCE TECHNOLOGY 2020; 317:124007. [PMID: 32799076 DOI: 10.1016/j.biortech.2020.124007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 08/07/2020] [Accepted: 08/10/2020] [Indexed: 05/15/2023]
Abstract
Microalgae Spirulina has good potential for bio-oil production. Therefore, kinetic and thermodynamic analysis of its pyrolysis process was performed. The activation energy values were estimated using both differential (109-340 kJ/mol) and integral (102-272 kJ/mol) isoconversional methods. Kinetic model was determined using master plot approach and the pyrolysis reaction appeared to transition between nucleation, diffusion and order-based kinetic models. Based on sigmoidal equations, a novel kinetic model equation was proposed which can define the pyrolysis process of algal biomass showing single differential thermogravimetric peak. The proposed kinetic triplet predicted the weight loss evolution quite precisely. Additionally, the thermodynamic feasibility of the reaction was examined based on enthalpy, entropy and Gibbs free energy. It was revealed that heat is consumed to make the raw sample reach a 'more orderly' state until a fractional conversion of 0.35. Moreover, bio-char and the remaining lipids at high temperature impede the reaction spontaneity towards the end.
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Affiliation(s)
- Vikul Vasudev
- Department of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China
| | - Xiaoke Ku
- Department of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China; State Key Laboratory of Clean Energy Utilization, Zhejiang University, 310027 Hangzhou, China.
| | - Jianzhong Lin
- Department of Engineering Mechanics, Zhejiang University, 310027 Hangzhou, China
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34
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Kinetic compensation effect: discounting the distortion provoked by accidental experimental errors in the isokinetic temperature value. MONATSHEFTE FUR CHEMIE 2020. [DOI: 10.1007/s00706-020-02710-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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VDAC Gating Thermodynamics, but Not Gating Kinetics, Are Virtually Temperature Independent. Biophys J 2020; 119:2584-2592. [PMID: 33189678 DOI: 10.1016/j.bpj.2020.10.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/06/2020] [Accepted: 10/16/2020] [Indexed: 12/17/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the most abundant protein in the mitochondrial outer membrane and an archetypical β-barrel channel. Here, we study the effects of temperature on VDAC channels reconstituted in planar lipid membranes at the single- and multichannel levels within the 20°C to 40°C range. The temperature dependence of conductance measured on a single channel in 1 M KCl shows an increase characterized by a 10°C temperature coefficient Q10 = 1.22 ± 0.02, which exceeds that of the bathing electrolyte solution conductivity, Q10 = 1.17 ± 0.01. The rates of voltage-induced channel transition between the open and closed states measured on multichannel membranes also show statistically significant increases, with temperatures that are consistent with activation energy barriers of ∼10 ± 3 kcal/mol. At the same time, the gating thermodynamics, as characterized by the gating charge and voltage of equipartitioning, does not display any measurable temperature dependence. The two parameters stay within 3.2 ± 0.2 elementary charges and 30 ± 2 mV, respectively. Thus, whereas the channel kinetics, specifically its conductance and rates of gating response to voltage steps, demonstrates a clear increase with temperature, the conformational voltage-dependent equilibria are virtually insensitive to temperature. These results, which may be a general feature of β-barrel channel gating, suggest either an entropy-driven gating mechanism or a role for enthalpy-entropy compensation.
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36
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Kinetic compensation effect of isoconversional methods. REACTION KINETICS MECHANISMS AND CATALYSIS 2020. [DOI: 10.1007/s11144-020-01898-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AbstractFor experimental data obtained under different reaction/process conditions over time or temperature, the kinetic compensation effect (KCE) can be expected. Under dynamic (nonisothermal) conditions, at least two analytical pathways forming the KCE were found. Constant heating rate (q = const) and variable conversion degrees (α = var) lead to a vertical source of the KCE, called the isochronal effect. In turn, for a variable heating rate (q = var) and constant conversion degree (α = const), we can obtain an isoconversional compensation effect. In isothermal conditions (analyzed as polyisothermal), the KCE appears only as an isoconversional source of the compensating effect. The scattering of values for the determined isokinetic temperatures is evidence of a strong influence of the experimental conditions and the calculation methodology. The parameters of the Arrhenius law have been shown to allow the determination of the KCE and further the isokinetic temperature. In turn, using the Eyring equations for the same parameters, we can determine the enthalpy–entropy compensation (EEC) for the activation process and the compensation temperature, which is often treated as an isokinetic temperature. KCE effects have also been shown to be able to be amplified or dissipated, but isokinetic temperature is not a compensating quantity in the literal sense in isoconversional methods because $${T}_{iso}\to \infty .$$
T
iso
→
∞
.
Thus, in isoconversional methods, isoconversional KCE values are characterized by strong variability of activation energy corresponding to the weak variation of the pre-exponential factor, which in practice means that $${\text{ln}}\mathit {A}\to {\text{const}}.$$
ln
A
→
const
.
This is completely in line with the classical Arrhenius law.
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37
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Iwasaki S, Koga N. Thermal dehydration of calcium sulfate dihydrate: physico-geometrical kinetic modeling and the influence of self-generated water vapor. Phys Chem Chem Phys 2020; 22:22436-22450. [PMID: 32996506 DOI: 10.1039/d0cp04195e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complex kinetic behaviors in the thermal dehydration of CaSO4·2H2O under varying water vapor pressure (p(H2O)) conditions impel researchers in the field of solid-state kinetics to gain a more comprehensive understanding. Both self-generated and atmospheric p(H2O) are responsible for determining the reaction pathways and the overall kinetic behaviors. This study focuses on the influence of the self-generated water vapor to obtain further insights into the complexity of the kinetic behaviors. The single-step mass-loss process under conditions generating a low p(H2O) was characterized kinetically by a physico-geometrical consecutive induction period, surface reaction, and phase boundary-controlled reaction, along with the evaluation of the kinetic parameters for the individual physico-geometrical reaction steps. Under the conditions in which more p(H2O) was generated, the overall reaction to form the anhydride was interpreted as a three-step process, comprising the initial reaction (direct dehydration to the anhydride) and a subsequent two-step reaction via the intermediate hemihydrate, which was caused by the variations in the self-generated p(H2O) conditions as the reaction advanced. The variations in the reaction pathways and kinetics behaviors under the self-generated p(H2O) conditions are discussed through a systematic kinetic analysis conducted using advanced kinetic approaches for the multistep process.
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Affiliation(s)
- Shun Iwasaki
- Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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38
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Kodani S, Koga N. Kinetics of contracting geometry-type reactions in the solid state: implications from the thermally induced transformation processes of α-oxalic acid dihydrate. Phys Chem Chem Phys 2020; 22:19560-19572. [PMID: 32936153 DOI: 10.1039/d0cp03176c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study focuses on the physico-geometrical constraints of the kinetics of the thermal decomposition of solids as exemplified by the thermal dehydration of α-oxalic acid dihydrate and the subsequent thermally induced sublimation/decomposition of the as-produced anhydride using the samples of crystalline particles (CPs) and a single crystal (SC) form. The CP and SC samples possess approximately similar geometrical figures with different sizes. The shapes of the original dihydrate and the as-produced anhydride from thermal dehydration are practically congruent. Therefore, proper evaluations of the current kinetic understanding of contracting geometry-type reactions were expected by the comparisons of the kinetic behaviors among different sample forms and thermally induced processes. The kinetic analysis of the thermal dehydration process revealed that the consecutive physico-geometrical processes comprised of an induction period, a surface reaction, and a phase boundary-controlled reaction, where distinguishable differences in the rate behavior were observed between the CP and SC samples for the surface reaction. On the other hand, the thermally induced sublimation/decomposition of the anhydride was described as an ideal single-step geometry contraction process, for which the CP and SC samples exhibited the same rate variation behavior under isothermal conditions. However, the sublimation/decomposition processes of the CP and SC samples were characterized by the different Arrhenius parameters, in which the compensative changes in the apparent activation energy and preexponential factor were apparent. Implications for the kinetic modeling of the solid-state reactions and the interpretation of kinetic results were obtained from the results of the comparative kinetic study for different sample forms and thermally induced processes.
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Affiliation(s)
- Satoki Kodani
- Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Nobuyoshi Koga
- Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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39
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Jiang S, Zeng Z, Xue W, Zhang W, Zhou Z. Kinetic study on the reaction of palmitic acid with ethanol catalyzed by deep eutectic solvent based on dodecyl trimethyl ammonium chloride. KOREAN J CHEM ENG 2020. [DOI: 10.1007/s11814-020-0557-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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40
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Xiang C, Liu H, Mu J, Lang Z, Wang H, Nie R, Kong F. Thermodynamic Model and Kinetic Compensation Effect of Spontaneous Combustion of Sulfur Concentrates. ACS OMEGA 2020; 5:20618-20629. [PMID: 32832815 PMCID: PMC7439706 DOI: 10.1021/acsomega.0c02884] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
The spontaneous combustion of the sulfur concentrate is the main hazard faced in ore storage bins. To understand the thermodynamic characteristics of spontaneous combustion of the sulfur concentrate and test whether the kinetic compensation effects are present in the spontaneous combustion process of the sulfur concentrate, typical sulfur concentrate samples were selected as the research object, and thermogravimetric experiments were carried out under an air atmosphere at heating rates of 5, 10, and 15 K/min. On this basis, the contributions of different reaction models to the mass change during the spontaneous combustion of the sulfur concentrate, as well as the thermodynamic model and kinetic compensation effect, are analyzed. The results show that solid-phase combustion contributes the most to mass loss among different mechanisms of the reaction between the sulfur concentrate and oxygen. The contributions of reaction models to mass loss are affected by the different heating rates, and the contribution of solid-phase combustion to mass loss increases with increasing heating rates. The Malek method is used to obtain the kinetic model of the spontaneous combustion of the sulfur concentrate, and its mechanism function changes from a chemical reaction model to a three-dimensional diffusion model. There is a kinetic compensation effect in the spontaneous combustion process of the sulfur concentrate, and the level of the kinetic compensation line may be one of the bases for distinguishing the spontaneous combustion tendency of the sulfur concentrate.
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Affiliation(s)
- Chenglang Xiang
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
| | - Hui Liu
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
| | - Jie Mu
- Zhejiang Academy of Safety Science and
Technology, Hangzhou 310011, China
| | - Zhihui Lang
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
| | - Haining Wang
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
| | - Rongshan Nie
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
| | - Fanyu Kong
- College of Quality
and Safety Engineering, China Jiliang University, Hangzhou 310018, China
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41
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Griessen R, Boelsma C, Schreuders H, Broedersz CP, Gremaud R, Dam B. Single Quality Factor for Enthalpy-Entropy Compensation, Isoequilibrium and Isokinetic Relationships. Chemphyschem 2020; 21:1632-1643. [PMID: 32573925 PMCID: PMC7522686 DOI: 10.1002/cphc.202000390] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/19/2020] [Indexed: 12/04/2022]
Abstract
Enthalpy-entropy compensation (EEC) is very often encountered in chemistry, biology and physics. Its origin is widely discussed since it would allow, for example, a very accurate tuning of the thermodynamic properties as a function of the reactants. However, EEC is often discarded as a statistical artefact, especially when only a limited temperature range is considered. We show that the likeliness of a statistical origin of an EEC can be established with a compensation quality factor (CQF) that depends only on the measured enthalpies and entropies and the experimental temperature range. This is directly derived from a comparison of the CQF with threshold values obtained from a large number of simulations with randomly generated Van 't Hoff plots. The value of CQF is furthermore a direct measure of the existence of a genuine isoequilibrium or isokinetic relationship.
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Affiliation(s)
- Ronald Griessen
- Condensed Matter PhysicsFaculty of SciencesVU University AmsterdamDe Boelelaan 10811081 HVAmsterdamThe Netherlands
| | - Christiaan Boelsma
- Tata Steel, Research and DevelopmentPO Box 100001970 CAIJmuidenThe Netherlands
| | - Herman Schreuders
- Materials for Energy Conversion and StorageDepartment of Chemical Engineering, Faculty of Applied SciencesDelft University of TechnologyVan der Maasweg 92629 HZDelftThe Netherlands
| | - Chase P. Broedersz
- Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScienceLudwig-Maximilians-Universität München80333MunichGermany
| | - Robin Gremaud
- ABB Switzerland LtdCorporate ResearchSegelhofstrasse 1 K5405Baden-DättwilSwitzerland
| | - Bernard Dam
- Materials for Energy Conversion and StorageDepartment of Chemical Engineering, Faculty of Applied SciencesDelft University of TechnologyVan der Maasweg 92629 HZDelftThe Netherlands
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42
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Kodani S, Iwasaki S, Favergeon L, Koga N. Revealing the effect of water vapor pressure on the kinetics of thermal decomposition of magnesium hydroxide. Phys Chem Chem Phys 2020; 22:13637-13649. [PMID: 32519687 DOI: 10.1039/d0cp00446d] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study aims to establish an advanced kinetic theory for reactions in solid state and solid-gas systems, achieving a universal kinetic description over a range of temperature and partial pressure of reactant or product gases. The thermal decomposition of Mg(OH)2 to MgO was selected as a model reaction system, and the effect of water vapor pressure p(H2O) on the kinetics was investigated via humidity controlled thermogravimetry. The reaction rate of the thermal decomposition process at a constant temperature was systematically decreased by increasing the p(H2O) value, accompanied by an increase in the sigmoidal feature of mass-loss curves. Under nonisothermal conditions at a given heating rate, mass-loss curves shifted systematically to higher temperatures depending on the p(H2O) value. The kinetic behavior under different temperature and p(H2O) conditions was universally analyzed by introducing an accommodation function (AF) of the form (P°/p(H2O))a[1 - (p(H2O)/Peq(T))b], where P° and Peq(T) are the standard and equilibrium pressures, respectively, into the fundamental kinetic equation. Two kinetic approaches were examined based on the isoconversional kinetic relationship and a physico-geometrical consecutive reaction model. In both the kinetic approaches, universal kinetic descriptions are achieved using the modified kinetic equation with the AF. The kinetic features of thermal decomposition are revealed by correlating the results from the two universal kinetic approaches. Furthermore, advanced features for the kinetic understanding of thermal decomposition of solids revealed by the universal kinetic descriptions are discussed by comparing the present kinetic results with those reported previously for the thermal decomposition of Ca(OH)2 and Cu(OH)2.
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Affiliation(s)
- Satoki Kodani
- Chemistry Laboratory, Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Shun Iwasaki
- Chemistry Laboratory, Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
| | - Loïc Favergeon
- Mines Saint-Etienne, University of Lyon, CNRS, UMR 5307 LGF, Centre Spin, F-42023 Saint-Etienne, France
| | - Nobuyoshi Koga
- Chemistry Laboratory, Department of Science Education, Graduate School of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima 739-8524, Japan.
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43
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Bessa W, Trache D, Derradji M, Tarchoun AF. Non‐Isothermal Curing Kinetics of Alkali‐Treated Alfa Fibers/Polybenzoxazine Composites Using Differential Scanning Calorimetry. ChemistrySelect 2020. [DOI: 10.1002/slct.202000596] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Wissam Bessa
- UER Procédés EnergétiquesEcole Militaire Polytechnique BP 17 Bordj El-Bahri 16046 Algiers Algeria
| | - Djalal Trache
- UER Procédés EnergétiquesEcole Militaire Polytechnique BP 17 Bordj El-Bahri 16046 Algiers Algeria
| | - Mehdi Derradji
- UER Procédés EnergétiquesEcole Militaire Polytechnique BP 17 Bordj El-Bahri 16046 Algiers Algeria
| | - Ahmed F. Tarchoun
- UER Procédés EnergétiquesEcole Militaire Polytechnique BP 17 Bordj El-Bahri 16046 Algiers Algeria
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44
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Ligand substitution in chromium(III)-aqua complexes by l-histidine: kinetic resolution of two long-lived intermediates. REACTION KINETICS MECHANISMS AND CATALYSIS 2019. [DOI: 10.1007/s11144-019-01637-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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45
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Liu X, Chen T, Jain PK, Xu W. Revealing the Thermodynamic Properties of Elementary Chemical Reactions at the Single-Molecule Level. J Phys Chem B 2019; 123:6253-6259. [PMID: 31246466 DOI: 10.1021/acs.jpcb.9b03474] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An understanding of the thermodynamic properties of elementary chemical steps of a reaction is important for the development of fundamental reaction theories and for effective industrial practice. In this work, temperature-variable single-molecule fluorescence microscopy was employed to study a reversible redox chemical process and reveal the thermodynamics of chemical elementary reactions at a single-molecule level. Activation energies of pure elementary steps were measured on the level of single molecules and found to be heterogeneously distributed across the population of individual molecules. The activation parameters measured across the population of individual molecules also exhibited a compensation effect and an isokinetic relationship. These results constitute a new single-molecule-level perspective into a chemical reaction.
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Affiliation(s)
- Xiaodong Liu
- State Key Laboratory of Electroanalytical Chemistry & Jilin Province Key Laboratory of Low Carbon Chemical Power , Changchun Institute of Applied Chemistry, Chinese Academy of Science , 5625 Renmin Street , Changchun 130022 , China.,University of Science and Technology of China , Anhui 230026 , China
| | - Tao Chen
- State Key Laboratory of Electroanalytical Chemistry & Jilin Province Key Laboratory of Low Carbon Chemical Power , Changchun Institute of Applied Chemistry, Chinese Academy of Science , 5625 Renmin Street , Changchun 130022 , China.,Graduate University of Chinese Academy of Science , Beijing 100049 , China
| | - Prashant K Jain
- Department of Chemistry & Beckman Institute of Advanced Science and Technology , University of Illinois at Urbana-Champaign , Urbana , Illinois 61801 , United States
| | - Weilin Xu
- State Key Laboratory of Electroanalytical Chemistry & Jilin Province Key Laboratory of Low Carbon Chemical Power , Changchun Institute of Applied Chemistry, Chinese Academy of Science , 5625 Renmin Street , Changchun 130022 , China.,University of Science and Technology of China , Anhui 230026 , China
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46
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Khrapunov S. The Enthalpy-entropy Compensation Phenomenon. Limitations for the Use of Some Basic Thermodynamic Equations. Curr Protein Pept Sci 2019; 19:1088-1091. [PMID: 29779476 DOI: 10.2174/1389203719666180521092615] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 05/10/2018] [Accepted: 05/16/2018] [Indexed: 11/22/2022]
Abstract
The thermodynamic analyses of proteins, protein-ligands and protein-nucleic acid complexes involves the entropy-enthalpy (S-H) compensation phenomenon. We have examined the question whether the observed compensation is artificial or reflects anything more than the well-known laws of statistical thermodynamics (so-called extra-thermodynamic compensation). We have shown that enthalpy- entropy compensation (EEC) is mainly the trivial consequence of the basic thermodynamic laws and there are no experimental evidences for existence of the extra-thermodynamic compensation. In most cases EEC obtained in the experiments through the plot enthalpies (ΔH) and entropies (TΔS) versus one another is meaningless due to the large correlated errors in ΔH and TΔS, unless special measures are taken to minimize, quantify and propagate these errors. Van't Hoff equation can be used for entropy calculation in limited cases when enthalpy is measured in independent experiments. Eyring equation cannot be used for calculation of entropy in any case and should be excluded from scientific use. Both equation, Van't Hoff and Eyring cannot be used for simultaneous calculation of the enthalpy and entropy values using one set of data. All the data obtained in this way should be recognized as erroneous.
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Affiliation(s)
- Sergei Khrapunov
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, United States
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47
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Abstract
The study of the rates of chemical reactions and their relationship to temperature began in the 19th century with empirical measurements of the time required to reach a particular reaction end point at a constant temperature. By the mid-20th century, the theory of reaction rates had advanced and instruments had been developed in which the temperature of the sample could be increased at a constant rate. These nonisothermal methods are now widely used to determine the kinetic parameters of reactions because of their convenience. In this paper, the mathematical relationship between measurements at constant temperature (isothermal) and constant heating rate (nonisothermal) is developed and it is shown that there is a point in the temperature history of a single-step reaction at which the isothermal and nonisothermal reaction rates are equal. This equal (iso) kinetic point occurs at a temperature early in the heating history of nonisothermal analyses at which the reaction rate begins to accelerate. The isokinetic temperature is the basis for a new method of nonisothermal kinetic analysis that provides a direct measurement of the Arrhenius frequency factor A and activation energy Ea for the elementary step of a solid-state reaction without any assumptions about the relationship between these parameters (i.e., kinetic compensation) or the reaction mechanism.
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Affiliation(s)
- Richard E Lyon
- Aviation Research Division, W. J. Hughes Technical Center , Federal Aviation Administration , Atlantic City International Airport , New Jersey 08405 , United States
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48
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Albinsson D, Nilsson S, Antosiewicz TJ, Zhdanov VP, Langhammer C. Heterodimers for in Situ Plasmonic Spectroscopy: Cu Nanoparticle Oxidation Kinetics, Kirkendall Effect, and Compensation in the Arrhenius Parameters. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:6284-6293. [PMID: 30906496 PMCID: PMC6428146 DOI: 10.1021/acs.jpcc.9b00323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 02/14/2019] [Indexed: 05/12/2023]
Abstract
The ability to study oxidation, reduction, and other chemical transformations of nanoparticles in real time and under realistic conditions is a nontrivial task due to their small dimensions and the often challenging environment in terms of temperature and pressure. For scrutinizing oxidation of metal nanoparticles, visible light optical spectroscopy based on the plasmonic properties of the metal has been established as a suitable method. However, directly relying on the plasmonic resonance of metal nanoparticles as a built-in probe to track oxidation has a number of drawbacks, including the loss of optical contrast in the late oxidation stages. To address these intrinsic limitations, we present a plasmonic heterodimer-based nanospectroscopy approach, which enables continuous self-referencing by using polarized light to eliminate parasitic signals and provides large optical contrast all the way to complete oxidation. Using Au-Cu heterodimers and combining experiments with finite-difference time-domain simulations, we quantitatively analyze the oxidation kinetics of ca. 30 nm sized Cu nanoparticles up to complete oxidation. Taking the Kirkendall effect into account, we extract the corresponding apparent Arrhenius parameters at various extents of oxidation and find that they exhibit a significant compensation effect, implying that changes in the oxidation mechanism occur as oxidation progresses and the structure of the formed oxide evolves. In a wider perspective, our work promotes the use of model-system-type in situ optical plasmonic spectroscopy experiments in combination with electrodynamics simulations to quantitatively analyze and mechanistically interpret oxidation of metal nanoparticles and the corresponding kinetics in demanding chemical environments, such as in heterogeneous catalysis.
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Affiliation(s)
- David Albinsson
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | - Sara Nilsson
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
| | | | - Vladimir P. Zhdanov
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
- Boreskov
Institute of Catalysis, Russian Academy
of Sciences, Novosibirsk 630090, Russia
| | - Christoph Langhammer
- Department
of Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden
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Vlasov VM. Influence of the activation entropy on the change of the isokinetic temperature in the SN2 reactions in solution. MONATSHEFTE FUR CHEMIE 2018. [DOI: 10.1007/s00706-018-2321-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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A Practical Approach for Data Gathering for Polymer Cure Simulations. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8112227] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Producing precision parts requires good control of the production parameters. When casting thermoset polymers an understanding of the curing process, with its heat release and associated temperature changes, is important. This paper describes how the cure of a polymer of unknown detailed chemical composition in a large part can be predicted and how the necessary material properties required for the predictions can be obtained. The approach given is a relatively simple method that a part manufacturer can perform. It will not characterize chemical reactions in detail, but it gives sufficient accuracy to describe the process. The procedures will be explained for an example of casting a large block of a filled two-component thermoset polyurethane. The prediction of the degree of cure, the associated heat and temperature increase during the curing of a polymer was successfully done using a standard finite element program with the input parameters reaction energy, the Arrhenius pre-factor and the kinetic function, which describes the chemical reaction. The three parameters could be obtained with standard Differential Scanning Calorimetry (DSC) equipment. The data were analyzed with the model-free isoconversional method combined with the compensation effect. The same set of parameters allowed the prediction of experimental cure behavior over two orders of magnitude of time and at a curing temperature range from room temperature up to 420 K.
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