scholarly journals Multi- and instabilities in gas partitioning between nanoporous materials and rubber balloons

2019 ◽  
Vol 475 (2222) ◽  
pp. 20180703 ◽  
Author(s):  
Cory M. Simon ◽  
Carlo Carraro
Keyword(s):  
Thermodynamic Equilibrium ◽  
Stable States ◽  
Temperature Changes ◽  
Adsorbed Gas ◽  
Rubber Balloon ◽  
Balloon Size ◽  
Metal Organic ◽  
Balloon Experiment ◽  
Adsorbent System ◽  
Balloon System

In the two-balloon experiment, two rubber balloons are connected and allowed to exchange gas. Owing to the non-monotonic relationship between the radius of the balloon and the pressure of gas inside it, the two-balloon system presents multi- and in-stabilities. Herein, we consider a two-adsorbent system, where two different adsorbents are allowed to exchange gas. We show that, for rigid adsorbents, the thermodynamic equilibrium state is unique. Then, we consider an adsorbent–balloon system, where an adsorbent exchanges gas with a rubber balloon. This system can exhibit multiple states at thermodynamic equilibrium– two (meta)stable and one unstable. The size of the balloon, pressure of gas in the balloon, and partitioning of gas between the adsorbent and the balloon differ among the equilibrium states. Temperature changes and the addition/removal of gas into/from the adsorbent–balloon system can induce catastrophe bifurcations and show hysteresis. Furthermore, the adsorbent–balloon system exhibits a critical temperature where, when approached from below, the discrepancy of balloon size between the two (meta)stable states decreases and, beyond, bistability is impossible. Practically, our findings preclude multiple partitions of adsorbed gas in rigid, mixed-linker or stratified metal-organic frameworks and may inspire new soft actuator and sensor designs.

Multi- and In-Stabilities in Gas Partitioning Between Nanoporous Materials and Rubber Balloons

2018 ◽  
Author(s):  
Cory Simon ◽  
carlo carraro
Keyword(s):  
Thermodynamic Equilibrium ◽  
Stable States ◽  
Temperature Changes ◽  
Adsorbed Gas ◽  
Rubber Balloon ◽  
Balloon Size ◽  
Metal Organic ◽  
Balloon Experiment ◽  
Adsorbent System ◽  
Balloon System

<div>In the two-balloon experiment, two rubber balloons are connected and allowed to exchange gas. Owing to the non-monotonic relationship between the radius of the balloon and the pressure of gas inside of it, the two-balloon system presents multi- and in-stabilities.</div><div><br></div><div>Herein, we consider a two-adsorbent system, where two different adsorbents are allowed to exchange gas. We show that, for rigid adsorbents, the thermodynamic equilibrium state is unique.</div><div><br></div><div>Then, we consider an adsorbent-balloon system, where an adsorbent exchanges gas with a rubber balloon. This system can exhibit multiple states at thermodynamic equilibrium-- two (meta)stable and one unstable. The size of the balloon, pressure of gas in the balloon, and partitioning of gas between the adsorbent and the balloon differ among the equilibrium states. Temperature changes and the addition/removal of gas into/from the adsorbent-balloon system can induce catastrophe bifurcations and show hysteresis. Furthermore, the adsorbent-balloon system exhibits a critical temperature where, when approached from below, the discrepancy of balloon size between the two (meta)stable states decreases and, beyond, bistability is impossible.</div><div><br></div><div>Practically, our findings preclude multiple partitions of adsorbed gas in rigid mixed-linker metal-organic frameworks and may inspire new soft actuator and sensor designs.</div>

Multi- and In-Stabilities in Gas Partitioning Between Nanoporous Materials and Rubber Balloons

2018 ◽  
Author(s):  
Cory Simon ◽  
carlo carraro
Keyword(s):  
Thermodynamic Equilibrium ◽  
Stable States ◽  
Temperature Changes ◽  
Adsorbed Gas ◽  
Rubber Balloon ◽  
Balloon Size ◽  
Metal Organic ◽  
Balloon Experiment ◽  
Adsorbent System ◽  
Balloon System

<div>In the two-balloon experiment, two rubber balloons are connected and allowed to exchange gas. Owing to the non-monotonic relationship between the radius of the balloon and the pressure of gas inside of it, the two-balloon system presents multi- and in-stabilities.</div><div><br></div><div>Herein, we consider a two-adsorbent system, where two different adsorbents are allowed to exchange gas. We show that, for rigid adsorbents, the thermodynamic equilibrium state is unique.</div><div><br></div><div>Then, we consider an adsorbent-balloon system, where an adsorbent exchanges gas with a rubber balloon. This system can exhibit multiple states at thermodynamic equilibrium-- two (meta)stable and one unstable. The size of the balloon, pressure of gas in the balloon, and partitioning of gas between the adsorbent and the balloon differ among the equilibrium states. Temperature changes and the addition/removal of gas into/from the adsorbent-balloon system can induce catastrophe bifurcations and show hysteresis. Furthermore, the adsorbent-balloon system exhibits a critical temperature where, when approached from below, the discrepancy of balloon size between the two (meta)stable states decreases and, beyond, bistability is impossible.</div><div><br></div><div>Practically, our findings preclude multiple partitions of adsorbed gas in rigid mixed-linker metal-organic frameworks and may inspire new soft actuator and sensor designs.</div>

scholarly journals Unravelling thermal stress due to thermal expansion mismatch in metal–organic frameworks for methane storage

2021 ◽  
Author(s):  
Jelle Wieme ◽  
Veronique Van Speybroeck
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Pressure Coefficient ◽  
Metal Organic Frameworks ◽  
Methane Storage ◽  
Thermal Expansion Mismatch ◽  
Thermal Pressure ◽  
Temperature Changes ◽  
Metal Organic ◽  
The Impact

Thermal stress is present in metal–organic frameworks undergoing temperature changes during adsorption and desorption. We computed the thermal pressure coefficient as a proxy for this phenomenon and discuss the impact of thermal expansion mismatch.

scholarly journals Effect of pore size and shape on the thermal conductivity of metal-organic frameworks

2017 ◽  
Vol 8 (1) ◽  
pp. 583-589 ◽  
Author(s):  
Hasan Babaei ◽  
Alan J. H. McGaughey ◽  
Christopher E. Wilmer
Keyword(s):  
Thermal Conductivity ◽  
Pore Size ◽  
Metal Organic Frameworks ◽  
Molecular Simulations ◽  
Size And Shape ◽  
Adsorbed Gas ◽  
Metal Organic

We investigate the effect of pore size and shape on the thermal conductivity of a series of idealized metal-organic frameworks (MOFs) containing adsorbed gas using molecular simulations.

scholarly journals Local thermodynamics governs the formation and dissolution of protein condensates in living cells

2021 ◽  
Author(s):  
Anatol W. Fritsch ◽  
Andrés F. Diaz-Delgadillo ◽  
Omar Adame-Arana ◽  
Carsten Hoege ◽  
Matthäus Mittasch ◽  
...  
Keyword(s):  
Phase Separation ◽  
Thermodynamic Equilibrium ◽  
Spatial Organization ◽  
Living Cells ◽  
Fast Diffusion ◽  
Temperature Changes ◽  
P Granules ◽  
Active Processes ◽  
Molecular Components ◽  
The Impact

Membraneless compartments, also known as condensates, provide chemically distinct environments and thus spatially organize the cell. A well-studied example of condensates is P granules in the roundworm C. elegans which play an important role in the development of the germline. P granules are RNA-rich protein condensates that share the key properties of liquid droplets such as a spherical shape, the ability to fuse, and fast diffusion of their molecular components. An outstanding question is to what extent phase separation at thermodynamic equilibrium is appropriate to describe the formation of condensates in an active cellular environment. To address this question, we investigate the response of P granule condensates in living cells to temperature changes. We observe that P granules dissolve upon increasing the temperature and recondense upon lowering the temperature in a reversible manner. Strikingly, this temperature response can be captured by in vivo phase diagrams which are well described by a Flory-Huggins model at thermodynamic equilibrium. This finding is surprising due to active processes in a living cell. To address the impact of such active processes on intra-cellular phase separation, we discuss temperature heterogeneities. We show that, for typical estimates of the density of active processes, temperature represents a well-defined variable and that mesoscopic volume elements are at local thermodynamic equilibrium. Our findings provide strong evidence that P granule assembly and disassembly are governed by phase separation based on local thermal equilibria where the non-equilibrium nature of the cytoplasm is manifested on larger scales.SIGNIFICANCE STATEMENTLiving cells rely on a continuous flux of energy to spatially organize biochemical processes. It remained unclear whether cells can achieve this spatial organization via thermodynamic principles. Here, we report the striking behavior of a cold-blooded organism that reacts to environmental temperature changes similar to a thermodynamic system at local equilibrium. Our key finding is that protein-rich droplets form and dissolve reversibly with temperature due to changes in the organism?s entropy. We show that the organism uses a specific molecule to extend droplet stability to the natural temperature range of the organism’s habitat. Due to the relevance of such protein droplets for the organism?s fertility, our works shed light on how molecular components could facilitate biological functions via thermodynamic principles.

scholarly journals Predicting the Features of Methane Adsorption in Large Pore Metal-Organic Frameworks for Energy Storage

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 818 ◽  
Author(s):  
George Manos ◽  
Lawrence Dunne
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Gas Storage ◽  
Methane Adsorption ◽  
Energy Applications ◽  
Adsorbed Gas ◽  
Theoretical Approaches ◽  
Large Pore ◽  
Metal Organic ◽  
Computer Simulation Studies

Currently, metal-organic frameworks (MOFs) are receiving significant attention as part of an international push to use their special properties in an extensive variety of energy applications. In particular, MOFs have exceptional potential for gas storage especially for methane and hydrogen for automobiles. However, using theoretical approaches to investigate this important problem presents various difficulties. Here we present the outcomes of a basic theoretical investigation into methane adsorption in large pore MOFs with the aim of capturing the unique features of this phenomenon. We have developed a pseudo one-dimensional statistical mechanical theory of adsorption of gas in a MOF with both narrow and large pores, which is solved exactly using a transfer matrix technique in the Osmotic Ensemble (OE). The theory effectively describes the distinctive features of adsorption of gas isotherms in MOFs. The characteristic forms of adsorption isotherms in MOFs reflect changes in structure caused by adsorption of gas and compressive stress. Of extraordinary importance for gas storage for energy applications, we find two regimes of Negative gas adsorption (NGA) where gas pressure causes the MOF to transform from the large pore to the narrow pore structure. These transformations can be induced by mechanical compression and conceivably used in an engine to discharge adsorbed gas from the MOF. The elements which govern NGA in MOFs with large pores are identified. Our study may help guide the difficult program of work for computer simulation studies of gas storage in MOFs with large pores.

Thermodynamic equilibrium and metal-organic interface dipole

2002 ◽  
Vol 81 (15) ◽  
pp. 2752-2754 ◽  
Author(s):  
Li Yan ◽  
N. J. Watkins ◽  
S. Zorba ◽  
Yongli Gao ◽  
C. W. Tang
Keyword(s):  
Thermodynamic Equilibrium ◽  
Interface Dipole ◽  
Metal Organic

Direct Measurement of Adsorbed Gas Redistribution in Metal–Organic Frameworks

2015 ◽  
Vol 137 (8) ◽  
pp. 2919-2930 ◽  
Author(s):  
Ying-Pin Chen ◽  
Yangyang Liu ◽  
Dahuan Liu ◽  
Mathieu Bosch ◽  
Hong-Cai Zhou
Keyword(s):  
Direct Measurement ◽  
Metal Organic Frameworks ◽  
Adsorbed Gas ◽  
Metal Organic

scholarly journals The use of the coherer to investigate adsorption films

1924 ◽  
Vol 106 (735) ◽  
pp. 55-68 ◽  
Keyword(s):  
Specific Effect ◽  
Systematic Investigation ◽  
Carbon Filament ◽  
Thermo Electric ◽  
Temperature Changes ◽  
Additional Information ◽  
Adsorbed Gas ◽  
Tungsten Filaments ◽  
Fine Tungsten ◽  
The Stability

In spite of the former widespread use of the "coherer" or loose-contact detector of electric waves, and the numerous researches on its mode of action, no systematic investigation appears to have been undertaken to ascertain the effect on the detector of the gas surrounding the contact. Branly and others suggested that the cohering effect under electric stress across the contact might be due to the dispersion of a badly-conducting film originally lying between the metal surfaces at the point of contact. This hypothesis appears to be con­firmed by the results described below, which indicate not only a highly specific effect for each gas, but an effect in agreement with the known phenomena of adsorption of gases at solid surfaces. The possibility that additional information might be obtained about the stability and formation of these films was the incentive to the present work. The theory of Eccles, founded upon the thermo-electric properties of the metals in contact and depending upon temperature changes at the point of contact, seems to be untenable when it is found that cohering action can certainly occur with a frequency of 10 6 times a second. In the investigation described below, contacts between fine tungsten filaments taken from an old lamp, between platinum filaments, and between carbon-tungsten surfaces were studied. The first named material is admirably suited for these experiments, which are held to depend upon the formation of films of adsorbed gas, as by reason of its very refractory properties it can be raised to a high temperature in order to clean the surface. In addition there is the advantage that the filaments must have been exceptionally well glowed-out during the working of the lamp of which they formed a part. The same advantage applies to the carbon filament used.

Electron microscope characterization of MOCVD-grown gap layers on Si

1986 ◽  
Vol 44 ◽  
pp. 724-725
Author(s):  
K.M. Jones ◽  
M.M. Al-Jassim ◽  
J.M. Olson
Keyword(s):  
Atmospheric Pressure ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Lattice Match ◽  
Si Substrates ◽  
Metal Organic ◽  
Good Lattice ◽  
Antiphase Domains

The epitaxial growth of III-V semiconductors on Si for integrated optoelectronic applications is currently of great interest. GaP, with a lattice constant close to that of Si, is an attractive buffer between Si and, for example, GaAsP. In spite of the good lattice match, the growth of device quality GaP on Si is not without difficulty. The formation of antiphase domains, the difficulty in cleaning the Si substrates prior to growth, and the poor layer morphology are some of the problems encountered. In this work, the structural perfection of GaP layers was investigated as a function of several process variables including growth rate and temperature, and Si substrate orientation. The GaP layers were grown in an atmospheric pressure metal organic chemical vapour deposition (MOCVD) system using trimethylgallium and phosphine in H2. The Si substrates orientations used were (100), 2° off (100) towards (110), (111) and (211).

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