Between glass and gas: Thermodynamics of liquid matter
TL;DR: In this article, it was shown that disorder is not a great obstacle for calculating thermodynamic properties of liquids, and that changes of thermodynamics properties are governed only by its average interatomic separation.
Abstract: We show that disorder is not a great obstacle for calculating thermodynamic properties of liquids. We discuss recent experimental, theoretical and modelling results related to excitations in liquids, and demonstrate how these data help to understand liquid thermodynamics. An important insight is the understanding that changes of thermodynamic properties of liquids are governed only by its average interatomic separation.
Citations
More filters
TL;DR: A review of the plasma physics of liquids can be found in this paper, where the main difficulties in understanding revolve around the basic mechanisms of plasma initiation in the liquid phase and the electrical interactions at a plasma-liquid interface, which require an interdisciplinary approach.
Abstract: The interaction of plasma with liquids has led to various established industrial implementations as well as promising applications, including high-voltage switching, chemical analysis, nanomaterial synthesis, and plasma medicine. Along with these numerous accomplishments, the physics of plasma in liquid or in contact with a liquid surface has emerged as a bipartite research field, for which we introduce here the term “plasma physics of liquids.” Despite the intensive research investments during the recent decennia, this field is plagued by some controversies and gaps in knowledge, which might restrict further progress. The main difficulties in understanding revolve around the basic mechanisms of plasma initiation in the liquid phase and the electrical interactions at a plasma-liquid interface, which require an interdisciplinary approach. This review aims to provide the wide applied physics community with a general overview of the field, as well as the opportunities for interdisciplinary research on topics, such as nanobubbles and the floating water bridge, and involving the research domains of amorphous semiconductors, solid state physics, thermodynamics, material science, analytical chemistry, electrochemistry, and molecular dynamics simulations. In addition, we provoke awareness of experts in the field on yet underappreciated question marks. Accordingly, a strategy for future experimental and simulation work is proposed.
145 citations
TL;DR: It is found that the pair distribution function smoothly evolves across the FL displaying medium-range order, and low-frequency transverse excitations are observed below the "Frenkel frequency", indicating that positive sound dispersion characterizing the liquid-like region of the supercritical state is unrelated to transverse dynamics.
Abstract: The “Frenkel line” (FL), the thermodynamic locus where the time for a particle to move by its size equals the shortest transverse oscillation period, has been proposed as a boundary between recently discovered liquid-like and gas-like regions in supercritical fluids We report a simulation study of isothermal supercritical neon in a range of densities intersecting the FL Specifically, structural properties and single-particle and collective dynamics are scrutinized to unveil the onset of any anomalous behavior at the FL We find that (i) the pair distribution function smoothly evolves across the FL displaying medium-range order, (ii) low-frequency transverse excitations are observed below the “Frenkel frequency”, and (iii) the high-frequency shear modulus does not vanish even for low-density fluids, indicating that positive sound dispersion characterizing the liquid-like region of the supercritical state is unrelated to transverse dynamics These facts critically undermine the definition of the FL and it
47 citations
TL;DR: In this article, the authors proposed a model where high-frequency vibrational modes, which travel at the speed of sound and have a mean free path on the order of the average intermolecular distance, conduct heat in liquids.
Abstract: Developing predictive thermal property models for liquids based on microscopic principles has been elusive. The difficulty is that liquids have gas-like and solid-like attributes that are at odds when considering the frameworks of microscopic models: Models for gases are simple due to randomness and low density, whereas models for crystalline solids rely on symmetry and long-range order for easier calculation. The short-range order in liquids does, however, provide structure to neighboring molecules similar to amorphous solids, and there have been recent advances indicating that collective vibrational modes store heat in liquids. Models combining Debye approximations from solid-state physics and Frenkel’s theory of liquids can accurately predict the heat capacity of liquids. Phonon-like dispersions in liquids have also been widely observed in neutron scattering experiments. These developments motivate us to propose a model where high-frequency vibrational modes, which travel at the speed of sound and have a mean free path on the order of the average intermolecular distance, conduct heat in liquids. We use this liquid phonon gas model to calculate the thermal conductivity of liquids with varying intermolecular interaction energies from strongest to weakest—Coulomb, hydrogen-bonding, Keesom, and London dispersion energy. Generally, the model is more accurate as the intermolecular interaction energy and density of liquids increase. The calculated thermal conductivity of Coulombic-bound molten sodium nitrate and hydrogen-bonded water is within 1.46% and 2.98% of the experimentally measured values, respectively, across their entire temperature ranges. Further modal analysis of the velocity and the mean free path of collective vibrations could establish the liquid phonon gas model as an accurate model for weakly interacting liquids as well.
13 citations
TL;DR: In this paper, the authors provide a brief overview of the fundamental mechanisms in laser-matter interaction as proposed in literature, and throw the spotlight on some aspects that have not received much attention yet.
12 citations
TL;DR: In this paper, theoretical and experimental evidence for the existence of a boundary between a solid-like melt and a dense gas at supercritical pressures is discussed, and the boundary is shown to exist at high pressure.
Abstract: It is an experimental fact that in the neighborhood of melting curves, including those measured at above-critical pressures and temperatures, all fluids have some short- and intermediate-range order and their excitation spectra contain high-frequency transverse waves. At high pressure, both smooth and sharp first-order phase transitions involving changes in the liquid structure and properties can occur between various liquid states. However, at sufficiently high temperatures, any liquid loses its identity and turns into an unstructured dense gas in which only longitudinal waves can propagate. We discuss theoretical and experimental evidence for the existence of a boundary between a 'solid-like' melt and a dense gas at supercritical pressures.
11 citations
References
More filters
Book•
01 Jan 1976
TL;DR: In this article, the authors present a mathematical model for time-dependent correlation functions and response functions in liquid solvers, based on statistical mechanics and molecular distribution functions, and show that these functions are related to time correlation functions in Ionic and Ionic liquids.
Abstract: Introduction. Statistical Mechanics and Molecular Distribution Functions. Computer "Experiments" on Liquids. Diagrammatic Expansions. Distribution Function Theories. Perturbation Theories. Time-dependent Correlation Functions and Response Functions. Hydrodynamics And Transport Coefficients. Microscopic Theories of Time-Correlation Functions. Ionic Liquids. Simple Liquid Metals. Molecular Liquids. Appendices. References. Index.
9,144 citations
TL;DR: In this paper, the authors reviewed the basic characteristics of the liquid-glass transition, emphasizing its universality and briefly summarizing the most popular phenomenological models, focusing on a number of alternative models which one way or the other connect the fast and slow degrees of freedom of viscous liquids.
Abstract: Basic characteristics of the liquid-glass transition are reviewed, emphasizing its universality and briefly summarizing the most popular phenomenological models. Discussion is focused on a number of alternative models which one way or the other connect the fast and slow degrees of freedom of viscous liquids. It is shown that all these ``elastic'' models are equivalent in the simplest approximation.
1,080 citations
Book•
01 Jan 1962
TL;DR: In this article, the Liouville equation is used to relate the memory function to the time correlation function of the fluctuations of the fluxes, a key result in modern non-equilibrium statistical mechanics.
Abstract: In the preceding chapter we discussed the microscopic foundations of extended irreversible thermodynamics through fluctuation theory. The present chapter deals with more general methods of non-equilibrium statistical mechanics. First, we start from the Liouville equation and introduce the projection operator technique to relate the memory function to the time correlation function of the fluctuations of the fluxes, a key result in modern non-equilibrium statistical mechanics. This result is of special interest in EIT, because it emphasizes the role played by the evolution of the fluctuations of the thermodynamic fluxes. Furthermore, the method of projection operators is useful, since it provides an explicit method for formulating the dynamical equations of the basic variables. Classically, the set of variables consists of the conserved slow variables (energy, linear momentum, mass) and some order parameters characterizing second-order phase transitions. Here we shall present a generalization of this method by adding the dissipative fast fluxes to the basic set of variables.
960 citations