Article
Chemistry, Physical
Shaolei Gai, Zhengbiao Peng, Behdad Moghtaderi, Jianglong Yu, Elham Doroodchi
Summary: This study presents a theoretical model based on molecular kinetic energy distribution to predict homogeneous ice nucleation (HIN) rate, showing good accuracy in predicting HIN temperatures under different pressures. Nonlinear variations of ice germ size and concentration were discovered, indicating the potential error in linearly extrapolating water characteristics in low-temperature regions using data obtained at high temperatures.
JOURNAL OF MOLECULAR LIQUIDS
(2021)
Article
Physics, Multidisciplinary
Amrita Goswami, Indranil Saha Dalal, Jayant K. Singh
Summary: Using molecular simulations and modified classical nucleation theory, this study investigates the nucleation of various liquids under flow. The results reveal a universal variation of nucleation rate with shear, and a simplified theory successfully explains the nonmonotonic temperature dependence of nucleation behavior.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Adam McElligott, Andre Guerra, Alexia Denoncourt, Alejandro D. Rey, Phillip Servio
Summary: This study investigates the freezing of up to three simultaneous THF hydrate droplets using acoustic levitation, revealing different nucleation mechanisms and structural inhomogeneities within the droplets.
Article
Physics, Fluids & Plasmas
A. Escobar, F. Donado, R. E. Moctezuma, Eric R. Weeks
Summary: In a quasi-two-dimensional system of magnetic spherical particles on a shallow concave dish under a temporally oscillating magnetic field, the energy losses from collisions and friction with the dish surface are compensated by continuous energy input from the magnetic field. Particle motions resemble that of atoms and molecules in glass or crystal-forming fluid, experiencing an additional force towards the center of the dish due to its curvature. Decreasing the magnetic field leads to decreased effective temperature and slower particle motion, eventually resulting in crystallization and the growth of a hexagonal lattice structure. The study supports nonclassical theories of crystal formation, where initially a dense amorphous aggregate of particles forms and rearranges internally to form the crystalline nucleus before growing into a crystal following classical theory.
Article
Polymer Science
Jewon Choi, Seyoung Kim, Jin Yoo, Soo-Hyung Choi, Kookheon Char
Summary: Random amphiphilic copolymers containing a large fraction of ureidopyrimidinone (UPy) were synthesized to produce antifreeze and dynamic hydrogels. The directional packing of UPy-UPy dimers provides nanosized aggregates with narrow gap distances, inhibiting water crystallization by the confinement effect. The temperature-dependent dynamics of UPy allow the hydrogels to form a frozen structure at lower temperatures and exhibit injectability and self-healing properties at room temperature, with negligible cytotoxicity expanding the potential applications in drug storage and cell cryopreservation.
Article
Chemistry, Physical
Leonardo Perin, Paola Gallo
Summary: In this study, molecular dynamics simulations were used to investigate the thermodynamics and structure of supercooled aqueous solutions of lithium chloride (LiCl) at concentrations c = 0.678 and 2.034 mol/kg. The presence of a liquid-liquid phase transition was observed at c = 0.678 mol/kg, similar to bulk water. The estimated position of the liquid-liquid critical point was T (c) ≈ 174K, P (c) ≈ 1775 bar, and ρ(c) ≈ 1.065 g/cm(3). No critical point was observed when the concentration was tripled to c = 2.034 mol/kg, indicating a possible disappearance of the critical point at this concentration. The structure of water-water and water-ions in the solutions was also studied, and it was found that the effect of ions on the water-water structure was not significant, preserving the features of bulk water. The hydration number of Li and Cl ions was calculated, and the results matched experimental findings, confirming the good performance of the Madrid-2019 force field.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Norihito Kimizuka
Summary: Research shows that a metastable eutectic is formed when an NaCl aqueous solution is cooled as a water-in-oil emulsion, with a eutectic point around -28 degrees C. This phenomenon can be predicted using phase diagrams.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Physics, Fluids & Plasmas
Rodolphe Grivet, Axel Huerre, Thomas Seon, Christophe Josserand
Summary: We experimentally explore the influence of solidification on the splashing phenomenon. By investigating the impact of water drops on dry smooth surfaces, we find that cooling the surface below the liquid melting temperature can greatly reduce the transition velocity to splash. At very low temperatures (below -60°C), the splashing behavior becomes independent of surface undercooling and exhibits similar characteristics as on ambient temperature superhydrophobic surfaces. This similarity is attributed to the increase of the dynamic advancing contact angle of the lamella with surface undercooling, transitioning from isothermal hydrophilicity to superhydrophobic behavior, which is related to ice growth near the contact line. Furthermore, we demonstrate that the transition from hydrophilic to superhydrophobic behavior can be quantitatively characterized based on the dynamics of the ejected droplets.
PHYSICAL REVIEW FLUIDS
(2023)
Article
Chemistry, Multidisciplinary
Yue Zhao, Fansen Zeng, Dachuan Zhao, Lei Lin, Zhengcai Zhang
Summary: This study investigates the growth process of carbon dioxide hydrate in the presence of salt through systematic molecular dynamics simulations. The results show that the growth rate of hydrate decreases with increasing solution salinity, and the number of ions bound in the hydrate structure is related to the growth rate and salinity. The replacement of water molecules by ions at the vertex of the cages is energetically unfavorable. The temperature has a maximum effect on the growth rate, while pressure has a negligible impact. The ion concentration in the hydrate phase decreases with temperature and is hardly affected by pressure. The trapping of ions in the hydrate phase is kinetically controlled by ion diffusion properties.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Physics, Fluids & Plasmas
Julien Sebilleau, Emeryk Ablonet, Philippe Tordjeman, Dominique Legendre
Summary: The humidity in the air influences the kinetics of icing front and the shape of the iced drop by inducing a liquid-vapor phase change at the icing droplet interface, affecting heat transfer. Experimental results show good agreement with a modified Stefan model that considers the effects of humidity on both front kinetics and tip angle.
Article
Chemistry, Physical
Joseph Kangas, John C. Bischof, Christopher J. Hogan
Summary: This paper extends the classic Avrami equation to nonisothermal systems with arbitrary temperature-time history and initial distributions of transformed phase. By examining phase change in Fourier space, a nonlinear differential equation relating nucleation rate, growth rate, and transformed fraction is derived. Analytical solutions for the population balance partial differential equation on the phase size distribution are obtained, and initial conditions for the differential equation linking nucleation rate, growth rate, and transformed fraction are derived.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Mahabir Prasad, Niall J. English, Somendra Nath Chakraborty
Summary: We studied the effect of static electric fields on the hydrogen bond structure and dynamics of TIP4P/2005 water. Electric fields of 0.1 and 0.4 V/nm had no additional effect on the water's changes, while a field of 1.0 V/nm enhanced the slowing down of dynamics and caused crystallization or amorphization. With increased electric fields, H-bonds became stronger, but the asymmetry between donor/acceptor bonds remained.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ignacio Sanchez-Burgos, Andres R. Tejedor, Carlos Vega, Maria M. Conde, Eduardo Sanz, Jorge Ramirez, J. O. R. G. E. R. Espinosa
Summary: This work investigates the nucleation rates of water under various supercooling conditions using computer simulations. The study compares two different water models and finds that the TIP4P/ICE model provides more accurate predictions of nucleation rates compared to the mW model.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Fausto Martelli, Jeremy C. Palmer
Summary: We investigated the spontaneous crystallization of water in the ST2 model under deeply supercooled conditions using molecular dynamics simulations. The ST2 model separates into low-density liquid and high-density liquid phases, promoting the formation of a sub-critical ice nucleus. Polymorphic selection favors the formation of cubic ice over hexagonal ice, and the critical nucleus absorbs both types of crystallites in the liquid phase.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Debdas Dhabal, Subramanian K. R. S. Sankaranarayanan, Valeria Molinero
Summary: Coarse-grained water models are more efficient than all-atom models, allowing simulations of supercooled water and crystallization. The machine-learned monatomic model ML-BOP reproduces the experimental equation of state and ice-liquid thermodynamics at 0.1 MPa with similar accuracy to existing all-atom models. The accuracy of ML-BOP is attributed to its ability to capture structural changes under different pressures and temperatures.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Physical
Jose Martin-Roca, Valentino Bianco, Francisco Alarcon, Ajay K. Monnappa, Paolo Natale, Francisco Monroy, Belen Orgaz, Ivan Lopez-Montero, Chantal Valeriani
Summary: Bacterial biofilms are viscoelastic media consisting of bacteria cross-linked to extracellular polymeric substances (EPSs) embedded in water. A mechanical modeling approach using Dissipative Particle Dynamics (DPD) captures the interactions between bacterial particles and cross-linked EPS-embedding under shear stress. The proposed DPD simulation qualitatively captures the rheology of P. fluorescens biofilm over several decades of dynamic scaling.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
G. D. Soria, A. Serrano, J. E. Prieto, A. Quesada, G. Gorni, J. de la Figuera, J. F. Marco
Summary: We investigated the influence of the annealing treatment on the crystalline growth of previously deposited SrFe12O19 films on Si (100) substrates by RF magnetron sputtering. The results showed that the as-grown film consisted of nanocrystalline maghemite nanoparticles and amorphous strontium oxide, while the annealed film exhibited a strontium hexaferrite canonical structure with a c-axis orientation. The findings were obtained through various analysis techniques, including Mossbauer spectroscopy, EXAFS, and XANES data.
JOURNAL OF MATERIALS RESEARCH
(2023)
Article
Chemistry, Physical
Cintia P. Lamas, Carlos Vega, Eva G. Noya, Eduardo Sanz
Summary: The formation of vapor bubbles in a metastable liquid, known as cavitation, has attracted much attention due to its practical implications. Different experimental strategies and theoretical analyses have been employed to measure and predict the cavitation line of liquid water. In this study, molecular simulations were used to fill the gap in understanding the cavitation rate dependence on pressure and temperature. The results revealed a comprehensive view of the water cavitation phenomenon and provided an efficient strategy for further investigation.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Ignacio Sanchez-Burgos, Maria Carolina Muniz, Jorge R. Espinosa, Athanassios Z. Panagiotopoulos
Summary: In this study, the Deep Potential methodology was used to investigate the phase transition of liquid water to vapor. The machine learning model was trained on ab initio energies and forces based on the SCAN density functional. Various properties, such as surface tension, saturation pressure, and enthalpy of vaporization, were computed and compared with experimental data and a classical model. The results showed a deviation in nucleation rates due to an underestimation of surface tension in the Deep Potential model, and also revealed a preferential orientation of water molecules in the liquid-vapor interface.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Editorial Material
Chemistry, Physical
Michele Ceriotti, Lasse Jensen, David E. Manolopoulos, Todd Martinez, David R. Reichman, Francesco Sciortino, C. David Sherrill, Qiang Shi, Carlos Vega, Lai-Sheng Wang, Emily A. Weiss, Xiaoyang Zhu, Jenny Stein, Tianquan Lian
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Cintia P. Lamas, Eduardo Sanz, Carlos Vega, Eva G. Noya
Summary: The liquid-vapor transition is initiated by the formation of a large enough bubble in the metastable liquid. However, understanding and studying this process is challenging due to the timescales involved. The seeding method, which simulates a liquid with an inserted bubble, provides a practical approach to estimate cavitation rates without the need for long times of bubble formation. The applicability of this method to homogeneous cavitation in mixtures is demonstrated in this work.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Jesus Algaba, Ivan M. Zeron, Jose Manuel Miguez, Joanna Grabowska, Samuel Blazquez, Eduardo Sanz, Carlos Vega, Felipe J. Blas
Summary: In this paper, the solubility of CO2 in water at 400 bar is determined using computer simulations. The solubility decreases in a liquid-liquid system with increasing temperature, while it increases in a hydrate-liquid system. The results are compared with previous work and a new method for evaluating the change in chemical potential for hydrate formation is proposed.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Jorge R. R. Espinosa, Jose Luis F. Abascal, Lucia F. F. Sedano, Eduardo Sanz, Carlos Vega
Summary: The anomalous behavior of water can be explained by the presence of a liquid-liquid critical point (LLCP) buried within the supercooled regime. A modified water potential accurately reproduces the experimental compressibility and equation of state, confirming the location of the model LLCP. The estimated experimental LLCP is located at approximately 1250 bar and 195 K based on the pressure shift required to recover the behavior of supercooled water.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
P. Montero de Hijes, J. R. Espinosa, C. Vega, C. Dellago
Summary: Despite the lack of research on ice nucleation at negative pressures, this study explores homogeneous ice nucleation in stretched water using molecular dynamics simulations. The results show that the critical nucleus size, interfacial free energy, free energy barrier, and nucleation rate remain constant across a wide pressure range. Additionally, the pressure dependence of the interfacial free energy is found to be related to the excess entropy and the slope of the melting line. The study also estimates the excess internal energy and entropy of the ice-water interface.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Andres R. Tejedor, Rosana Collepardo-Guevara, Jorge Ramirez, Jorge R. Espinosa
Summary: Biomolecular condensates are important for cellular organization and have diverse material properties. This study compares three computational methods for measuring the viscoelasticity of condensates and finds that the Green-Kubo and oscillatory shear techniques outperform the bead tracking method. The study also reveals correlations between condensate viscosity and density, protein/RNA length, and amino acid protein sequence.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
S. Blazquez, M. M. Conde, C. Vega, E. Sanz
Summary: CO2 and CH4 hydrates are important both energetically and environmentally. Molecular dynamics simulations reveal that the growth rate of these hydrates is affected by the incorporation of guest molecules, with CO2 hydrate growing faster due to higher solubility. Additionally, higher temperatures require more molecular motion for solid growth. Our calculations show good agreement with experiments of hydrate growth along the guest-solution interface, but further work is needed to reconcile different experimental results.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Samuel Blazquez, Jose L. F. Abascal, Jelle Lagerweij, Parsa Habibi, Poulumi Dey, Thijs J. H. Vlugt, Othonas A. Moultos, Carlos Vega
Summary: In this study, the electrical conductivities of aqueous NaCl and KCl solutions under ambient conditions were computed using the Einstein-Helfand equation. Conventional force fields could not accurately predict the experimental values of electrical conductivities, viscosities, and diffusion coefficients. However, by introducing the concept of using different charges to describe the potential energy surface and the dipole moment surface, excellent agreement with experimental results was achieved for the first time for the entire concentration range.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)