scholarly journals Desorption energy of soft particles from a fluid interface

Soft Matter ◽  
2020 ◽  
Vol 16 (37) ◽  
pp. 8655-8666
Author(s):  
Hadi Mehrabian ◽  
Jacco H. Snoeijer ◽  
Jens Harting
Keyword(s):  
Free Energy ◽  
Mechanical Work ◽  
Fluid Interface ◽  
Desorption Energy ◽  
Soft Particles

The efficiency of soft particles to stabilize emulsions is examined by measuring their desorption free energy, i.e., the mechanical work required to detach the particle from a fluid interface.

scholarly journals Remodeler Catalyzed Nucleosome Repositioning: Influence of Structure and Stability

2020 ◽  
Vol 22 (1) ◽  
pp. 76
Author(s):  
Aaron Morgan ◽  
Sarah LeGresley ◽  
Christopher Fischer
Keyword(s):  
Free Energy ◽  
Dna Replication ◽  
Recent Work ◽  
Chromatin Remodeling ◽  
Chromatin Structure ◽  
Genetic Information ◽  
Molecular Machines ◽  
Mechanical Work ◽  
Eukaryotic Genome ◽  
Hydrolysis Of

The packaging of the eukaryotic genome into chromatin regulates the storage of genetic information, including the access of the cell’s DNA metabolism machinery. Indeed, since the processes of DNA replication, translation, and repair require access to the underlying DNA, several mechanisms, both active and passive, have evolved by which chromatin structure can be regulated and modified. One mechanism relies upon the function of chromatin remodeling enzymes which couple the free energy obtained from the binding and hydrolysis of ATP to the mechanical work of repositioning and rearranging nucleosomes. Here, we review recent work on the nucleosome mobilization activity of this essential family of molecular machines.

scholarly journals Equilibrium Orientation and Adsorption of an Ellipsoidal Janus Particle at a Fluid–Fluid Interface

2020 ◽  
Vol 4 (4) ◽  
pp. 55
Author(s):  
Florian Günther ◽  
Qingguang Xie ◽  
Jens Harting
Keyword(s):  
Free Energy ◽  
Lattice Boltzmann ◽  
Adsorption Process ◽  
Particle Surface ◽  
Fluid Interface ◽  
Janus Particle ◽  
Energy Models ◽  
Lattice Boltzmann Simulations ◽  
Theoretical Predictions ◽  
Particle Aspect Ratio

We investigate the equilibrium orientation and adsorption process of a single, ellipsoidal Janus particle at a fluid–fluid interface. The particle surface comprises equally sized parts that are hydrophobic or hydrophilic. We present free energy models to predict the equilibrium orientation and compare the theoretical predictions with lattice Boltzmann simulations. We find that the deformation of the fluid interface strongly influences the equilibrium orientation of the Janus ellipsoid. The adsorption process of the Janus ellipsoid can lead to different final orientations determined by the interplay of particle aspect ratio and particle wettablity contrast.

Dynamics and Wetting Behavior of Core–Shell Soft Particles at a Fluid–Fluid Interface

Langmuir ◽  
2018 ◽  
Vol 34 (50) ◽  
pp. 15370-15382 ◽  
Author(s):  
Siddarth A. Vasudevan ◽  
Astrid Rauh ◽  
Martin Kröger ◽  
Matthias Karg ◽  
Lucio Isa
Keyword(s):  
Core Shell ◽  
Fluid Interface ◽  
Wetting Behavior ◽  
Soft Particles

scholarly journals The free energy of glycogen-lactic acid breakdown in muscle

1929 ◽  
Vol 104 (729) ◽  
pp. 153-170 ◽  
Keyword(s):  
Molecular Structure ◽  
Free Energy ◽  
Lactic Acid ◽  
Chemical Reactions ◽  
Thermodynamic Data ◽  
Chemical Change ◽  
Mechanical Work ◽  
The Other ◽  
Heat Of Reaction ◽  
Negative Difference

It is the purpose of the present discussion to show, upon the basis of thermodynamic data obtained within the last four of five years, that the free energy of glycogen-lactic acid breakdown in muscle is considerably greater than the heat of reaction, about one and one-half to two times. It is the intention to outline merely the orders of magnitude of the various quantities involved in the evaluation of this difference. This evaluation, as will be shown, need not depend upon a knowledge of the actual heat of reaction, which is still in dispute, varying between Meyerhof's value of —180 cal. and Slater's value of —235 cal. It will depend, rather, upon the specific heat differences, or ultimately, molecular structure differences, obtaining between glycogen and lactic acid. Stated briefly, the existence of this large negative difference, designated hereafter as (ΔF — ΔH), implies that the theoretical maximum mechanical work which a muscle can perform as a consequence of this breakdown is considerably greater than the corresponding heat of reaction. The notations of Lewis and Randall (1) will be used throughout. ΔH, the heat of reaction, and ΔF, the free energy of reaction, will be negative when heat and free energy respectively are liberated. Before presenting the thermodynamic data and calculations, it will be it historical interest to point out that in 1912 A. V. Hill (2) suggested the possibility of such a difference, when he first made the observation that during anaerobic lactic acid formation in muscle the heat evolved amounted to at least three times as much as would have been predicted if the precursor were a hexose carbohydrate. He suggested, "the breakdown from this body to lactic acid may be one of those somewhat rare but by no means unknown chemical reactions which can do more mechanical work than is equivalent to their total loss of energy; by virtue of their completeness they possess the power of absorbing heat from their surroundings to do this excess of work." Meyerhof (3, 1922) reconsidered the question, and while alive to the possibility of a considerable difference, offered an opinion, based upon the Nernst heat theorem, that probably no difference did exist. In general, however, little attention has been paid to A. V. Hill's original surmise, especially since further investigation of the other hydrolysis, neutralization, and deionization reactions occurring simultaneously with the formation of lactic acid, has shifted the attention to explaining the other more immediate problem, namely, the discrepancy between the observed chemical change and the required evolution of heat.

scholarly journals Adsorption of soft particles at fluid interfaces

Soft Matter ◽  
2015 ◽  
Vol 11 (37) ◽  
pp. 7412-7419 ◽  
Author(s):  
Robert W. Style ◽  
Lucio Isa ◽  
Eric R. Dufresne
Keyword(s):  
Fluid Interfaces ◽  
Fluid Interface ◽  
Soft Particles

We explain why soft particles make good emulsifiers by analysing their deformations at a fluid–fluid interface.

scholarly journals Efficient conversion of chemical energy into mechanical work by Hsp70 chaperones

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Salvatore Assenza ◽  
Alberto Stefano Sassi ◽  
Ruth Kellner ◽  
Benjamin Schuler ◽  
Paolo De Los Rios ◽  
...  
Keyword(s):  
Free Energy ◽  
Single Molecule ◽  
Atp Hydrolysis ◽  
Critical Role ◽  
Quantitative Agreement ◽  
Mechanical Work ◽  
Chemical Energy ◽  
Coarse Grained ◽  
Theoretical Approaches ◽  
Non Equilibrium

Hsp70 molecular chaperones are abundant ATP-dependent nanomachines that actively reshape non-native, misfolded proteins and assist a wide variety of essential cellular processes. Here, we combine complementary theoretical approaches to elucidate the structural and thermodynamic details of the chaperone-induced expansion of a substrate protein, with a particular emphasis on the critical role played by ATP hydrolysis. We first determine the conformational free-energy cost of the substrate expansion due to the binding of multiple chaperones using coarse-grained molecular simulations. We then exploit this result to implement a non-equilibrium rate model which estimates the degree of expansion as a function of the free energy provided by ATP hydrolysis. Our results are in quantitative agreement with recent single-molecule FRET experiments and highlight the stark non-equilibrium nature of the process, showing that Hsp70s are optimized to effectively convert chemical energy into mechanical work close to physiological conditions.

scholarly journals Physical Theory of Fluid Interfaces Near the Critical Point

1972 ◽  
Vol 25 (4) ◽  
pp. 367 ◽  
Author(s):  
KW Sarkies ◽  
P Richmond ◽  
BW Ninham
Keyword(s):  
Free Energy ◽  
Critical Point ◽  
Physical Theory ◽  
Scaling Laws ◽  
Continuum Theory ◽  
The Self ◽  
Fluid Interfaces ◽  
Fluid Interface ◽  
Simple Fluids ◽  
Energy Of Interaction

A continuum theory of surfaces is developed for fluids near their critical points. The free energy of the fluid interface is considered to consist of two terms: the self free energy of inhomogeneity and an energy of interaction across the interface due to van der Waals forces. This second term is computed via the principles of Lifshitz theory and gives a physical basis to Widom's modification of the Cahn?Hilliard theory of surfaces. The scaling laws as derived by Widom are recalculated, and several differences from the original laws emerge. The theory permits calculation of absolute values of surface tensions and interface widths near the critical point from experimental dielectric and free energy data. Furthermore, the fluids considered are not necessarily simple fluids where only pairwise forces are important.

Non-monotonic variations of the nucleation free energy in a glass-forming ultra-soft particles fluid

Soft Matter ◽  
2018 ◽  
Vol 14 (29) ◽  
pp. 5977-5985
Author(s):  
Caroline Desgranges ◽  
Jerome Delhommelle
Keyword(s):  
Free Energy ◽  
Glass Transition ◽  
Nucleation Behavior ◽  
Crystal Nucleus ◽  
Glass Forming ◽  
Soft Particles

Non-classical nucleation behavior arising from the interplay between the formation of a crystal nucleus and the glass transition.

scholarly journals Soft particles at a fluid interface

Soft Matter ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1062-1073 ◽  
Author(s):  
Hadi Mehrabian ◽  
Jens Harting ◽  
Jacco H. Snoeijer
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Young’S Modulus ◽  
Fluid Interfaces ◽  
Liquid Droplets ◽  
Fluid Interface ◽  
Rigid Particles ◽  
Soft Particles ◽  
Dynamics Simulations ◽  
Elastic Particles

Soft particles can be used as an alternative to rigid particles, to stabilise fluid interfaces in the oil, food, and cosmetic industries. Using molecular dynamics simulations and continuum calculations, it is shown that the shape of soft elastic particles at a fluid interface is not only affected by their Young's modulus, but also strongly depends on their wettability, analogous to liquid droplets.

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