Article
Materials Science, Coatings & Films
Brahim Ahammou, Paramita Bhattacharyya, Christophe Levallois, Fahmida Azmi, Jean-Pierre Landesman, Peter Mascher
Summary: Silicon nitride (SiNx) based films are widely used in the microelectronics and optoelectronics industry, as well as in building-integrated photovoltaics technologies. This study focuses on the deposition process and optimization of minimal parameters for stable plasma conditions during multilayer SiNx and SiOyNx film deposition. The influence of gas flow adjustments on the optical and mechanical properties, such as refractive index and mechanical stress, is investigated. Experimental results show a significant dependence of these properties on the deposition parameters, and thermal cycling experiments reveal the degradation mechanisms and irreversible variation of mechanical stress in SiNx films.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Physics, Applied
Martin Lee, Makars Siskins, Samuel Manas-Valero, Eugenio Coronado, Peter G. Steeneken, Herre S. J. van der Zant
Summary: The study investigates the CDW phase transition in suspended 2H-TaS2 and 2H-TaSe2 membranes using mechanical resonances, revealing that degradation can significantly affect transition temperatures, leading to multiple phase transitions and hysteresis in temperature.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Ceramics
Lulu Xie, Jianchao Lin, Xiaokang Zhong, Buke Dong, Rui Wang, Xiaoguang Zhu, Peng Tong, Wenhai Song, Yuping Sun
Summary: Negative thermal expansion (NTE) materials can be used to suppress thermal expansion and create composites with zero thermal expansion (ZTE). The composite of modified Cu2P2O7 and 2024Al exhibits ZTE effect, high thermal conductivity, and good machinability, indicating potential applications in high-precision electronics and optics.
CERAMICS INTERNATIONAL
(2023)
Article
Physics, Fluids & Plasmas
Matteo Baggioli, Alessio Zaccone
Summary: The study derives a theory of specific heat of liquids based on the vibrational density of states, explaining the typical decrease in specific heat with temperature and the correlation between liquid energy barriers and specific heat slopes. The findings demonstrate that the specific heat of liquids is controlled by instantaneous normal modes, providing a missing connection among anharmonicity, saddle points in the energy landscape, and the thermodynamics of liquids.
Article
Thermodynamics
Enrico Benassi, Haiyan Fan
Summary: Two formulae were developed to express the relationship between sublimation enthalpy, Young's modulus, and other thermodynamic properties based on a thermodynamic basis. These formulae provide alternative ways to quantitatively estimate important thermodynamic and mechanical properties for the development of new materials.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2021)
Article
Materials Science, Multidisciplinary
Palmerina Gonzalez-Izquierdo, Oscar Fabelo, Laura Canadillas-Delgado, Garikoitz Beobide, Oriol Vallcorba, Jorge Salgado-Beceiro, Manuel Sanchez-Andujar, Carmen Martin, Javier Ruiz-Fuentes, Jose Eduardo Garcia, Maria Teresa Fernandez-Diaz, Imanol de Pedro
Summary: Quinuclidinium salts and their derivatives are being focused on in materials science as building blocks for multifunctional materials due to their easily switchable properties. This study investigated the synthesis and physical properties of a homochiral hybrid halometallate ferroelectric compound using (R)-(-)-3-quinuclidinol hydrochloride. Through various diffraction techniques, the compound showed a series of structural and magnetic phase transitions at different temperatures, revealing unique magnetic structures and ferroelectric behaviors.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Polymer Science
Rahul Bhowmik, Sangwook Sihn, Ruth Pachter, Jonathan P. Vernon
Summary: Predicting the specific heat at constant pressure (Cp) of polymers using machine learning methods shows potential in designing novel polymers with desired properties;
Despite the relatively small dataset, the results indicate the usefulness of machine learning methods in predicting Cp;
Studying the impact of polymer descriptors on Cp could lead to experimental syntheses of novel materials with tailored properties.
Article
Engineering, Geological
Zi-jun Feng, Yang-sheng Zhao, Dong-na Liu
Summary: The research shows that the permeability of granite increases with temperature, with coarser-grained granite exhibiting a more significant increase in permeability. Factors such as grain size, temperature, and elastic modulus have a significant impact on thermal cracking and induced permeability.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Mechanical
Sarah Glaser, Omid Zarmandili, Elisabeth Stammen, Klaus Dilger
Summary: Understanding the curing mechanisms of adhesives is crucial for planning adhesive application and bonding processes. The demand for short manufacturing cycle times has driven the development of rapid curing adhesives. Investigating the curing behavior of fast-curing adhesives and their interaction with rheometric methods and measuring devices is essential for improving measurement accuracy.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING
(2022)
Article
Thermodynamics
Yongping Huang, Chengcheng Fan, Bo Li, Chengbin Zhang
Summary: The study investigates the influence of the thermal expansion and contraction property of phase change materials (PCMs) on the buoyancy-driven melting/solidification heat transfer in latent heat storage (LHS) units. A mathematical model is constructed to understand the mechanisms and explore the effects of different PCMs, heat transfer fluid (HTF) direction, and fin layout on the melting/solidification performance. The results show that the melting/solidification times are affected by the thermal properties of PCMs and the direction of HTF, while the fin layout can also impact the performance of PCMs with varying thermal characteristics.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Polymer Science
Alexander Korolev, Maxim Mishnev, Dmitrii Ulrikh, Alexander Zadorin
Summary: This study confirmed the models of the relations between the elastic modulus (MoE) and thermal expansivity (CTe) for thermosetting epoxy polymers and glass-fiber FRPs. The constants of the models depend on composition. Barker's model is applicable to polymers with a satisfying agreement degree of 10-20%, while our model is applicable to polymers and FRPs with a satisfying agreement degree of 6-18%.
Article
Forestry
Osman Emre Ozkan
Summary: This study investigated the effects of cryogenic temperatures on the mechanical properties of beech wood, showing that the bending strength and modulus of elasticity of the wood increased during freezing. The increase in mechanical strength properties could be attributed to the freezing of water, hardening of wood cell walls, decreasing intermolecular distance, increasing intermolecular force, and stabilization of crystalline structure.
EUROPEAN JOURNAL OF WOOD AND WOOD PRODUCTS
(2021)
Article
Engineering, Electrical & Electronic
Haolong Zhou, Wakana Hanafusa, Keigo Udo, Naoshi Hirai, Yoshimichi Ohki
Summary: In this study, flame-retardant cross-linked polyolefin, an important polymeric insulation material for electric power cables, is subjected to severe thermal and radiation stresses. The degradation of the polymer is found to be more severe under thermal aging compared to a combination of heat and gamma irradiation. The formation of densely cross-linked structures induced by gamma irradiation appears to enhance the polymer's hardness and resistance to oxidation and chemical bond scission.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Polymer Science
Henryk Bednarski, Barbara Hajduk
Summary: In this work, a new method for determining the dispersion of the thermo-optic coefficient in optical polymers is developed based on the Lorentz-Lorenz relationship. The method is validated on SiO2 glass and PMMA, and successfully explains the experimental results showing a linear relationship for the TOC of 9 different optical polymers.
Article
Energy & Fuels
Saeid Faraji, Hemayat Shekaari, Mohammed Taghi Zafarani-Moattar, Masumeh Mokhtarpour
Summary: Energy storage chemicals, such as ionic liquids, have potential for thermal energy storage due to their thermophysical properties. In this project, three protic ionic liquids were synthesized and evaluated for thermal energy storage. The ionic liquid 2-hydroxyethylammonium lactate showed higher heat capacity and thermal conductivity, making it a suitable candidate for thermal energy storage.
JOURNAL OF ENERGY STORAGE
(2022)
Article
Chemistry, Physical
Tina Hecksher, Niels Boye Olsen, Jeppe C. Dyre
Summary: Dynamic shear modulus data of two silicone oils, DC704 and DC705, were obtained and fitted using a phenomenological model. The model's alpha part was found to best fit the data, reinforcing the hypothesis of the proportionality between alpha relaxation and high-frequency loss decay with angular frequency.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Multidisciplinary Sciences
Birte Riechers, Lisa A. Roed, Saeed Mehri, Trond S. Ingebrigtsen, Tina Hecksher, Jeppe C. Dyre, Kristine Niss
Summary: The noncrystalline glassy state of matter is important in materials science and offers unique properties. However, it undergoes physical aging due to being out of equilibrium. The existence of a material time is validated and physical aging can be predicted using fluctuation-dissipation theorem and computer simulations.
Article
Chemistry, Physical
Eman Attia, Jeppe C. Dyre, Ulf R. Pedersen
Summary: By combining interface-pinning simulations and numerical integration, we accurately determined the melting-line coexistence pressure and fluid/crystal densities of the Weeks-Chandler-Andersen system across a wide range of temperatures. We compared the melting-line predictions of different approximations and found that the Andersen-Weeks-Chandler and Barker-Henderson theories provided the most accurate results, especially in the zero-temperature limit. Analytical expressions for this limit were derived in this study.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Correction
Chemistry, Physical
Ian H. Bell, Richard Messerly, Monika Thol, Lorenzo Costigliola, Jeppe C. Dyre
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Mechanics
Mathias Mikkelsen, Kira L. Eliasen, Niclas Lindemann, Kevin Moch, Roland Bohmer, Hossein Ali Karimi-Varzaneh, Jorge Lacayo-Pineda, Bo Jakobsen, Kristine Niss, Tage Christensen, Tina Hecksher
Summary: This article presents recent advances in the piezoelectric shear gauge (PSG) technique, including optimized data extraction and simplified measuring cell design. The technique is particularly suitable for measuring viscous liquids near their glass transition temperature.
JOURNAL OF RHEOLOGY
(2022)
Article
Chemistry, Physical
Mathias Mikkelsen, Jan Philipp Gabriel, Tina Hecksher
Summary: This study presents a dielectric and shear mechanical analysis of 1-propanol and three phenylpropanols. Unlike other mono-alcohols, phenylpropanols do not exhibit a bimodal behavior in their dielectric response, but instead show a single, narrow process. Combining the dielectric and light scattering spectra, it is found that the single peak in phenylpropanols can be separated into a self-correlation and a cross-correlation part, indicating the presence of hydrogen-bonded structures. Shear mechanical analysis supports this interpretation, showing a subtle polymer-like mode in the low-frequency range, similar to other mono-alcohols.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Physical
Jeppe C. Dyre, Ulf R. Pedersen
Summary: In this study, an alternative zero-parameter prediction method based on the isomorph theory and properties at a single reference state point is proposed to accurately predict the melting line of the WCA system at high temperatures, while the hard-sphere theory performs better at lower temperatures. Additionally, the results show that the excellent predictions of the isomorph theory for the WCA potential at higher temperatures may be partly due to a cancellation of errors between the two basic assumptions.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Trond S. Ingebrigtsen, Jeppe C. Dyre
Summary: The difference in structure and dynamics between size-polydisperse and energy-polydisperse liquids is studied numerically. It is found that while size-polydisperse systems show changes in average structure and dynamics, energy-polydisperse systems do not. Even with extreme energy polydispersity leading to phase separation, the average structure and dynamics remain unchanged. This is consistent with the fact that forces on individual particles do not change with energy polydispersity.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Zahraa Sheydaafar, Jeppe C. Dyre, Thomas B. Schroder
Summary: Isomorphs are curves in the thermodynamic phase diagram that exhibit structural and dynamic invariance. Tracing isomorphs can be done using different methods, such as configurational-adiabat and direct-isomorph-check. A recent force-based method, which only requires a single equilibrium configuration, shows promising results in atomic systems. In this study, we test the generalization of this method to molecular systems and compare it to simulations of three different molecular models.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Physics, Condensed Matter
Daniel Jespersen, Lorenzo Costigliola, Jeppe C. Dyre, Shibu Saw
Summary: This paper investigates the existence of isomorphs in size-polydisperse Lennard-Jones systems described by active Ornstein-Uhlenbeck particle (AOUP) dynamics. Isomorphs, which are curves of invariant structure and dynamics, are traced out from a single steady-state configuration using the configurational-temperature method. The study demonstrates good isomorph invariance for three uniform-distribution polydispersities and compares the results to active-matter isomorphs generated by another method.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Nanoscience & Nanotechnology
Sina Ariaee, Bo Jakobsen, Ib Host Pedersen, Torben Steen Rasmussen, Dorthe Posselt
Summary: A compact setup is presented for in situ solvothermal vapor annealing of thin polymer films. The setup is optimized to avoid solvent condensation and includes a chamber, a gas delivery system, a film-thickness measuring device, and a solvent vapor concentration sensor. Optical reflectometry is used for determining the film-swelling ratio and UV-absorption for monitoring the solvent concentration in the exhaust gas.
Article
Physics, Fluids & Plasmas
Saeed Mehri, Jeppe C. Dyre, Trond S. Ingebrigtsen
Summary: This paper investigates the smectic-B phase of the Gay-Berne liquid-crystal model at high density and low temperatures, complementing a previous study. The research reveals strong correlations between thermal fluctuations in the virial and potential energy, indicating the existence of isomorphs. Simulation results further confirm the approximate isomorph invariance through various physical properties. Thus, the isomorph theory can simplify the relevant regions of the Gay-Berne model for liquid-crystal experiments.
Article
Chemistry, Physical
Zahraa Sheydaafar, Jeppe C. Dyre, Thomas B. Schroder
Summary: Isomorphs are curves in the thermodynamic phase diagram where structure and dynamics are approximately invariant. There are two main methods for tracing isomorphs: the configurational-adiabat method and the direct-isomorph-check method. Recently, a new force-based method has been introduced and shown to work well for atomic systems. This method only requires a single equilibrium configuration for tracing isomorphs.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Trond S. Ingebrigtsen, Jeppe C. Dyre
Summary: Size-polydisperse liquids are commonly used as models for studying supercooled liquids and glasses formed by colloidal systems. In this study, we investigated the difference in structure and dynamics between size-polydisperse and energy-polydisperse liquids using numerical simulations. The results showed that the average structure and dynamics remain unchanged even for strong energy polydispersity, while they vary significantly in size-polydisperse systems. The distribution of forces on individual particles is believed to be the key factor contributing to these differences.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
