The Subtle Kinetics of Arrested Spinodal Decomposition: Colloidal Gels and Porous Glasses

MRS Advances ◽  
2018 ◽  
Vol 3 (63) ◽  
pp. 3817-3825 ◽  
Author(s):  
José Manuel Olais-Govea ◽  
Leticia López-Flores ◽  
Magdaleno Medina-Noyola
Keyword(s):  
Spinodal Decomposition ◽  
Irreversible Processes ◽  
Generalized Langevin Equation ◽  
Colloidal Gels ◽  
Simple Liquids ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Irreversible Relaxation ◽  
Kinetic Features ◽  
Non Equilibrium

ABSTRACTThe non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory of irreversible processes in liquids has been proposed as a theoretical framework capable of predicting the age- and preparation-dependent properties of highly ubiquitous non-equilibrium amorphous solids, such as like glasses and gels. By this formalism, we discuss the main kinetic features of the irreversible relaxation of simple liquids involved in the arrested spinodal decomposition of suddenly and deeply quenched. At some lower temperature we identify, by means of a latency time within which particles retain a finite apparently stationary mobility, the crossover from full phase separation to arrested spinodal decomposition which leads to recognize the onset of gelation.

Non-equilibrium relaxation and aging in the dynamics of a dipolar fluid quenched towards the glass transition

2021 ◽  
Author(s):  
Ricardo Peredo-Ortiz ◽  
Pablo Fernando Zubieta Rico ◽  
Ernesto Carlos Cortés Morales ◽  
Gabriel Pérez-Ángel ◽  
Thomas Voigtmann ◽  
...  
Keyword(s):  
Generalized Langevin Equation ◽  
Glass Transitions ◽  
Interacting Particles ◽  
Equilibrium Conditions ◽  
Dipolar Fluid ◽  
Hard Sphere Liquid ◽  
Self Consistent ◽  
Underlying Mechanisms ◽  
Irreversible Relaxation ◽  
Non Equilibrium

Abstract The recently developed non-equilibrium self-consistent generalized Langevin equation theory of the dynamics of liquids of non-spherically interacting particles [J. Phys. Chem. B 120, 7975 (2016)] is applied to the description of the irreversible relaxation of a thermally and mechanically quenched dipolar fluid. Specifically, we consider a dipolar hard-sphere liquid quenched (at tw = 0) from full equilibrium conditions towards different ergodic–non-ergodic transitions. Qualitatively different scenarios are predicted by the theory for the time evolution of the system after the quench (tw > 0), that depend on both the kind of transition approached and the specific features of the protocol of preparation. Each of these scenarios is characterized by the kinetics displayed by a set of structural correlations, and also by the development of two characteristic times describing the relaxation of the translational and rotational dynamics, allowing us to highlight the crossover from equilibration to aging in the system and leading to the prediction of different underlying mechanisms and relaxation laws for the dynamics at each of the glass transitions explored.

scholarly journals Interference between the glass, gel, and gas-liquid transitions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
José Manuel Olais-Govea ◽  
Leticia López-Flores ◽  
Jesús Benigno Zepeda-López ◽  
Magdaleno Medina-Noyola
Keyword(s):  
Glass Transition ◽  
First Principles ◽  
Liquid Glass ◽  
Irreversible Processes ◽  
Generalized Langevin Equation ◽  
Glass Transitions ◽  
Liquid Phase Transition ◽  
Self Consistent ◽  
Spinodal Line ◽  
Non Equilibrium

Abstract Recent experiments and computer simulations have revealed intriguing phenomenological fingerprints of the interference between the ordinary equilibrium gas-liquid phase transition and the non-equilibrium glass and gel transitions. We thus now know, for example, that the liquid-gas spinodal line and the glass transition loci intersect at a finite temperature and density, that when the gel and the glass transitions meet, mechanisms for multistep relaxation emerge, and that the formation of gels exhibits puzzling latency effects. In this work we demonstrate that the kinetic perspective of the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory of irreversible processes in liquids provides a unifying first-principles microscopic theoretical framework to describe these and other phenomena associated with spinodal decomposition, gelation, glass transition, and their combinations. The resulting scenario is in reality the competition between two kinetically limiting behaviors, associated with the two distinct dynamic arrest transitions in which the liquid-glass line is predicted to bifurcate at low densities, below its intersection with the spinodal line.

scholarly journals Recognition of hydrogen isotopomers by an open-cage fullerene

2013 ◽  
Vol 371 (1998) ◽  
pp. 20110629 ◽  
Author(s):  
Yasujiro Murata ◽  
Shih-Ching Chuang ◽  
Fumiyuki Tanabe ◽  
Michihisa Murata ◽  
Koichi Komatsu
Keyword(s):  
Equilibrium Constants ◽  
Equilibrium Mixture ◽  
Size Difference ◽  
Binding Affinities ◽  
Kinetic Isotope ◽  
Molecular Sizes ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Pressure Hydrogen

We present our study on the recognition of hydrogen isotopes by an open-cage fullerene through determination of binding affinity of isotopes H 2 /HD/D 2 with the open-cage fullerene and comparison of their relative molecular sizes through kinetic-isotope-release experiments. We took advantage of isotope H 2 /D 2 exchange that generated an equilibrium mixture of H 2 /HD/D 2 in a stainless steel autoclave to conduct high-pressure hydrogen insertion into an open-cage fullerene. The equilibrium constants of three isotopes with the open-cage fullerene were determined at various pressures and temperatures. Our results show a higher equilibrium constant for HD into open-cage fullerene than the other two isotopomers, which is consistent with its dipolar nature. D 2 molecule generally binds stronger than H 2 because of its heavier mass; however, the affinity for H 2 becomes larger than D 2 at lower temperature, when size effect becomes dominant. We further investigated the kinetics of H 2 /HD/D 2 release from open-cage fullerene, proving their relative escaping rates. D 2 was found to be the smallest and H 2 the largest molecule. This notion has not only supported the observed inversion of relative binding affinities between H 2 and D 2 , but also demonstrated that comparison of size difference of single molecules through non-convalent kinetic-isotope effect was applicable.

The Self-Decay Characteristics of Chlorine Dioxide in Water

2012 ◽  
Vol 610-613 ◽  
pp. 296-299
Author(s):  
Xin Jie Li ◽  
Dan Nan Jiang ◽  
Yue Jun Zhang
Keyword(s):  
Rate Constants ◽  
Tap Water ◽  
Pure Water ◽  
Decay Behaviour ◽  
Increase With Increase ◽  
Higher Temperature ◽  
Effects Of Temperature ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Temperature Water

In order to learn the ClO2 decay behaviour in tap water, the kinetics of ClO2 decay in pure water was studied. Under the conditions of tap water treatment and keeping away from light, the effects of temperature and pH on ClO2 degradation were investigated. The results show that the ClO2 decay reaction in pure water is the first-order with respect to ClO2, the decay rate constants increase with increase in temperature or pH. At pH=6.87, the rate constants are 0.012h-1(15°C), 0.017h-1(25°C), 0.023h-1(35°C), and 0.029h-1(45°C), respectively. At 25°C, the rate constants are 0.0083h-1(pH=4.5), 0.0111h-1(pH=5.5), 0.0143h-1(pH=6.5), 0.0222h-1(pH=7.5), and 0.0351h-1(pH=8.5), respectively. The experimental data prove that ClO2 is more stable in acidic or lower temperature water than in neutral, alkalescent, or higher temperature water.

Anisothermal densification kinetics of the cold sintering process below 150 °C

2020 ◽  
Vol 8 (17) ◽  
pp. 5668-5672 ◽  
Author(s):  
Sun Hwi Bang ◽  
Arnaud Ndayishimiye ◽  
Clive A. Randall
Keyword(s):  
Ceramic Powder ◽  
Sintering Process ◽  
Process Variables ◽  
Densification Process ◽  
Sintering Kinetics ◽  
Equilibrium Process ◽  
Process Methodology ◽  
Kinetics Of ◽  
Reduced Temperature ◽  
Non Equilibrium

Cold sintering is an emerging non-equilibrium process methodology that densifies ceramic powder at significantly reduced temperature and time, and its sintering kinetics can be identified by controlling four densification process variables.

A study of barium strontium titanate thin films for use in bypass capacitors

1998 ◽  
Vol 13 (1) ◽  
pp. 197-204 ◽  
Author(s):  
B. A. Baumert ◽  
L-H. Chang ◽  
A. T. Matsuda ◽  
C. J. Tracy ◽  
N. G. Cave ◽  
...  
Keyword(s):  
Thin Films ◽  
Perovskite Phase ◽  
Electrical Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Strontium ◽  
Aluminum Metallization ◽  
On Chip ◽  
Lower Temperature ◽  
Kinetics Of

Physical and electrical characterization techniques have been applied to the problem of developing a lower temperature process for spin-on Ba0.7Sr0.3TiO3 thin films and capacitors compatible with on-chip aluminum metallization. The films were prepared by spin-coating from carboxylate precursors and were processed at temperatures between 650 °C and 450 °C. Capacitors annealed at higher temperatures have a dielectric constant (κ) of 382, a C/A of 20 fF/μm2, and a leakage current density of 2 × 10−7 A/cm2 at 3.3 V. Those processed at 450 °C show occasionally promising but inconsistent results, correlated using TEM images with locally variable crystallization into the perovskite phase. The kinetics of the spin-on solution chemical decomposition and crystallization has been investigated through the use of x-ray diffraction (XRD), thermogravimetric analysis (TGA), and Raman spectroscopy.

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