Microscopic Evidence for Liquid-Liquid Separation in Supersaturated CaCO3 Solutions

Recent experimental observations of the onset of calcium carbonate (CaCO3) mineralization suggest the emergence of a population of clusters that are stable rather than unstable as predicted by classical nucleation theory. This study uses molecular dynamics simulations to probe the structure, dynamics, and energetics of hydrated CaCO3 clusters and lattice gas simulations to explore the behavior of cluster populations before nucleation. Our results predict formation of a dense liquid phase through liquid-liquid separation within the concentration range in which clusters are observed. Coalescence and solidification of nanoscale droplets results in formation of a solid phase, the structure of which is consistent with amorphous CaCO3. The presence of a liquid-liquid binodal enables a diverse set of experimental observations to be reconciled within the context of established phase-separation mechanisms.

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Cavitation in Liquids by Classical Nucleation Theory and Molecular Dynamics Simulations

Liquids Under Negative Pressure ◽

10.1007/978-94-010-0498-5_20 ◽

2002 ◽

pp. 231-242

Author(s):

C. Xiao ◽

D. M. Heyes ◽

M. E. Parker ◽

J. G. Powles

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Dynamics Simulations

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Dissolution and Growth Kinetics of Small Crystals in Liquids

MRS Proceedings ◽

10.1557/proc-238-279 ◽

1991 ◽

Vol 238 ◽

Author(s):

Michael J. Uttormark ◽

Michael O. Thompson ◽

Paulette Clancy

Keyword(s):

Molecular Dynamics ◽

Melting Point ◽

Driving Force ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Equilibrium Melting Point ◽

Small Crystals ◽

Dynamics Simulations ◽

Kinetics Of ◽

Nucleation Phenomenon

ABSTRACTMolecular Dynamics simulations of the melting of small crystalline clusters (≃800 atoms) in the liquid have been performed at various temperatures above the equilibrium melting point. The melting rates as functions of size and temperature are derived and compared to that predicted by Classical Nucleation Theory. It is found that the driving force for the melting of clusters does not follow the form assumed in the theory, and that this difference is most apparent for clusters containing less than 300 atoms. The implications of these findings on nucleation phenomenon and possible sources for the discrepancies are discussed.

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Homogeneous nucleation of NaCl in supersaturated solutions

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02093e ◽

2021 ◽

Author(s):

Cintia Pulido Lamas ◽

Jorge R. Espinosa ◽

María Martín Conde ◽

Jorge Ramirez ◽

Pablo Montero de Hijes ◽

...

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Homogeneous Nucleation ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Approximate Approach ◽

Seeding Method ◽

Dynamics Simulations ◽

Supersaturated Solutions

The Seeding method is an approximate approach to investigate nucleation that combines molecular dynamics simulations with classical nucleation theory. This technique has been successfully implemented in a broad range of...

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Fluctuations near the liquid–liquid transition in a model of silica

Physical Chemistry Chemical Physics ◽

10.1039/c8cp04237c ◽

2018 ◽

Vol 20 (39) ◽

pp. 25195-25202 ◽

Cited By ~ 2

Author(s):

Jingxiang Guo ◽

Jeremy C. Palmer

Keyword(s):

Molecular Dynamics ◽

Phase Separation ◽

Liquid Phase ◽

Molecular Dynamics Simulations ◽

Small Angle ◽

Ionic Model ◽

Liquid Transition ◽

Angle Scattering ◽

Dynamics Simulations ◽

Liquid Liquid Phase Separation

Molecular dynamics simulations reveal anomalous small-angle scattering and liquid–liquid phase separation in an ionic model of silica.

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Nucleation Parameters of SPC/E And TIP4P/2005 Water Vapor Measured In NPT Molecular Dynamics Simulations

10.21203/rs.3.rs-1177344/v1 ◽

2022 ◽

Author(s):

Tomáš Němec

Keyword(s):

Molecular Dynamics ◽

Steady State ◽

Water Vapor ◽

Standard Deviation ◽

Molecular Dynamics Simulations ◽

Nucleation Rate ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Nucleation Process ◽

Dynamics Simulations

Abstract Nucleation rates for droplet formation in water vapor are measured in molecular dynamics simulations of SPC/E and TIP4P/2005 water by monitoring individual nucleation events. The nucleation process is simulated in the NPT ensemble to evaluate the steady-state nucleation rate in accordance with the assumptions of classical nucleation theory (CNT). Nucleation rates measured between 300 K and 425 K for the SPC/E model, and between 325 K and 475 K for the TIP4P/2005 model, agree with the CNT predictions roughly within the standard deviation of the MD measurements of the nucleation rates.

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On the Role of Poly-Glutamic Acid in the Early Stages of Iron(III) (Oxy)(hydr)oxide Formation

Minerals ◽

10.3390/min11070715 ◽

2021 ◽

Vol 11 (7) ◽

pp. 715

Author(s):

Miodrag J. Lukić ◽

Felix Lücke ◽

Teodora Ilić ◽

Katharina Petrović ◽

Denis Gebauer

Keyword(s):

Fourier Transform ◽

Infrared Spectroscopy ◽

Phase Separation ◽

Fourier Transform Infrared Spectroscopy ◽

Fourier Transform Infrared ◽

Nucleation Theory ◽

Classical Nucleation Theory ◽

Oxide Formation ◽

Early Stages ◽

Titration Assay

Nucleation of minerals in the presence of additives is critical for achieving control over the formation of solids in biomineralization processes or during syntheses of advanced hybrid materials. Herein, we investigated the early stages of Fe(III) (oxy)(hydr)oxide formation with/without polyglutamic acid (pGlu) at low driving force for phase separation (pH 2.0 to 3.0). We employed an advanced pH-constant titration assay, X-ray diffraction, thermal analysis with mass spectrometry, Fourier Transform infrared spectroscopy, and scanning electron microscopy. Three stages were observed: initial binding, stabilization of Fe(III) pre-nucleation clusters (PNCs), and phase separation, yielding Fe(III) (oxy)(hydr)oxide. The data suggest that organic–inorganic interactions occurred via binding of olation Fe(III) PNC species. Fourier Transform Infrared Spectroscopy (FTIR) analyses revealed a plausible interaction motif and a conformational adaptation of the polypeptide. The stabilization of the aqueous Fe(III) system against nucleation by pGlu contrasts with the previously reported influence of poly-aspartic acid (pAsp). While this is difficult to explain based on classical nucleation theory, alternative notions such as the so-called PNC pathway provide a possible rationale. Developing a nucleation theory that successfully explains and predicts distinct influences for chemically similar additives like pAsp and pGlu is the Holy Grail toward advancing the knowledge of nucleation, early growth, and structure formation.

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Using Molecular Dynamics Simulations to Understand Electron Beam Interactions with Macromolecules in Liquid-phase Transmission Electron Microscopy

Microscopy and Microanalysis ◽

10.1017/s1431927621010084 ◽

2021 ◽

Vol 27 (S1) ◽

pp. 2892-2893

Author(s):

John Smith ◽

Chang Liu ◽

Qian Chen

Keyword(s):

Electron Microscopy ◽

Molecular Dynamics ◽

Transmission Electron Microscopy ◽

Electron Beam ◽

Liquid Phase ◽

Molecular Dynamics Simulations ◽

Transmission Electron ◽

Phase Transmission ◽

Dynamics Simulations

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Prion-Like Proteins in Phase Separation and Their Link to Disease

Biomolecules ◽

10.3390/biom11071014 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1014

Author(s):

Macy L. Sprunger ◽

Meredith E. Jackrel

Keyword(s):

Protein Folding ◽

Phase Transitions ◽

Phase Separation ◽

Liquid Phase ◽

Protein Misfolding ◽

Solid Phase ◽

Liquid Phase Separation ◽

Therapeutic Approaches ◽

Important Physiological Process ◽

Liquid Liquid Phase Separation

Aberrant protein folding underpins many neurodegenerative diseases as well as certain myopathies and cancers. Protein misfolding can be driven by the presence of distinctive prion and prion-like regions within certain proteins. These prion and prion-like regions have also been found to drive liquid-liquid phase separation. Liquid-liquid phase separation is thought to be an important physiological process, but one that is prone to malfunction. Thus, aberrant liquid-to-solid phase transitions may drive protein aggregation and fibrillization, which could give rise to pathological inclusions. Here, we review prions and prion-like proteins, their roles in phase separation and disease, as well as potential therapeutic approaches to counter aberrant phase transitions.

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