Driving Force for Hydrophobic Interaction at Different Length Scales

2011 ◽  
Vol 115 (10) ◽  
pp. 2303-2311 ◽  
Author(s):  
Ronen Zangi
2020 ◽  
Vol 7 (16) ◽  
pp. 2001048 ◽  
Author(s):  
Fan Xiao ◽  
Zhe Chen ◽  
Zixiang Wei ◽  
Leilei Tian

1996 ◽  
Vol 33 (6) ◽  
pp. 263-270 ◽  
Author(s):  
C. N. You ◽  
J. C. Liu

A study was conducted to assess the desorptive behavior of chlorophenols in contaminated soils. Two soils spiked with three types of chlorophenols, i.e., 2,6-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP), respectively, were examined. The effects of pH, methanol, surfactants, and soil properties were investigated. Amount of three chlorophenols desorbed from soils increased with increasing pH. Deprotonated chlorophenols were more mobile than their conjugate acids. When methanol was added to the soil-water system, the amount of chlorophenols desorbed increased. The desorption of PCP was enhanced in the presence of anionic surfactant, SDS. However, when non-ionic surfactant, TX-100, was present, the desorption of PCP decreased. The effects of pH and surfactants on desorptive behavior of chlorophenols were most significant on PCP. Generally, the amount of chlorophenol adsorption deceased in the order PCP > TCP > DCP. Hydrophobic interaction was found to be the major driving force of adsorption reactions. It was therefore proposed that hydrophobicity of chlorophenols is an important factor controlling their desorptive behavior.


RSC Advances ◽  
2021 ◽  
Vol 11 (46) ◽  
pp. 28667-28673
Author(s):  
Feiyi Zhang ◽  
Lanlan Yu ◽  
Wenbo Zhang ◽  
Lei Liu ◽  
Chenxuan Wang

Hydrophobic interaction provides the essential driving force for creating diverse native and artificial supramolecular architectures.


2018 ◽  
Author(s):  
Mrinmoy Mukherjee ◽  
Jagannath Mondal

AbstractOsmolytes’ mechanism of protecting proteins against denaturation is a longstanding puzzle, further complicated by the complex diversities inherent in protein sequences. An emergent approach in understanding osmolytes’ mechanism of action towards biopolymer has been to investigate osmolytes’ interplay with hydrophobic interaction, the major driving force of protein folding. However, the crucial question is whether all these protein-stabilizing osmolytes display a single unified mechanism towards hydrophobic interactions. By simulating the hydrophobic collapse of a macromolecule in aqueous solutions of two such osmoprotectants, Glycine and Trimethyl N-oxide (TMAO), both of which are known to stabilize protein’s folded conformation, we here demonstrate that these two osmolytes can impart mutually contrasting effects towards hydrophobic interaction. While TMAO preserves its protectant nature across diverse range of polymer-osmolyte interactions, glycine is found to display an interesting cross-over from being a protectant at weaker polymer-osmolyte interaction to a denaturant of hydrophobicity at stronger polymer-osmolyte interactions. A preferential-interaction analysis reveals that a subtle balance of conformation-dependent exclusion/binding of osmolyte molecules from/to the macromolecule holds the key to overall heterogenous behavior. Specifically, TMAO’s consistent stabilization of collapsed configuration of macromolecule is found to be a result of TMAO’s preferential binding to polymer via hydrophobic methyl groups. However, polar Glycine’s cross-over from being a protectant to denaturant across polymer-osmolyte interaction is rooted in its switch from preferential exclusion to preferential binding to the polymer with increasing interaction. Overall, by highlighting the complex interplay of osmolytes with hydrophobic interaction, this work puts forward the necessity of quantitative categorization of osmolytes’ action in protein.


2012 ◽  
Vol 715-716 ◽  
pp. 764-769
Author(s):  
Sina Shahandeh ◽  
Matthias Militzer

Modelling the evolution of structures in polycrystalline materials with distributions of fine particles requires integration of multiple length scales. Grain boundaries interact with particles on the scale of the particle diameters. The particle pinning force controls the kinetics of grain growth. Grain diameters can be several orders of magnitude larger than particles. In this work, a methodology is proposed to combine two sets of phase field models at different length scales. At the smaller scale, the effect of particles on movement of a single grain boundary is modelled in a small domain with a high grid resolution. The interface moves in an array of particles with specified shape and size distributions. The average pinning force exerted by the particles, is calculated from the interface velocity. Then, an effective driving force model is developed to incorporate the obtained pinning force into the large scale where grain growth simulations are preformed. In this model, the particle pinning force is subtracted from the driving force in the phase field formulation. In this effective formulation, particles are not resolved in the calculation grid. Therefore, with the larger numerical mesh, modelling of larger systems is possible. Kinetics of grain growth was studied with 2 dimensional simulations. Keywords: Phase field modelling, particle pinning, grain growth


Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.


Author(s):  
P. J. Goodhew

Cavity nucleation and growth at grain and phase boundaries is of concern because it can lead to failure during creep and can lead to embrittlement as a result of radiation damage. Two major types of cavity are usually distinguished: The term bubble is applied to a cavity which contains gas at a pressure which is at least sufficient to support the surface tension (2g/r for a spherical bubble of radius r and surface energy g). The term void is generally applied to any cavity which contains less gas than this, but is not necessarily empty of gas. A void would therefore tend to shrink in the absence of any imposed driving force for growth, whereas a bubble would be stable or would tend to grow. It is widely considered that cavity nucleation always requires the presence of one or more gas atoms. However since it is extremely difficult to prepare experimental materials with a gas impurity concentration lower than their eventual cavity concentration there is little to be gained by debating this point.


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