scholarly journals Calculation of van der Waals Interaction Energy in Free Liquid Films Accounting for Many-body Contributions

2012 ◽  
Vol 41 (10) ◽  
pp. 1253-1255 ◽  
Author(s):  
Kirill A. Emelyanenko ◽  
Alexandre M. Emelyanenko ◽  
Ludmila Boinovich
Keyword(s):  
Interaction Energy ◽  
Van Der Waals ◽  
Liquid Films ◽  
Van Der Waals Interaction ◽  
Many Body

scholarly journals Van der Waals interactions between polymers with sequence-specific polarizabilities: Stiff polymers and Gaussian coils

2016 ◽  
Vol 31 (02n03) ◽  
pp. 1641035 ◽  
Author(s):  
Bing-Sui Lu ◽  
Ali Naji ◽  
Rudolf Podgornik
Keyword(s):  
Interaction Energy ◽  
Van Der Waals ◽  
Pairwise Interaction ◽  
Van Der Waals Interaction ◽  
Van Der Waals Interactions ◽  
Attractive Interaction ◽  
Gyration Radius ◽  
Interaction Energies ◽  
Anisotropic Interaction ◽  
Decay Behavior

We consider the van der Waals interaction between a pair of polymers with quenched heterogeneous sequences of local polarizabilities along their backbones, and study the effective pairwise interaction energy for both stiff polymers and flexible Gaussian coils. In particular, we focus on the cases where the pair of polarizability sequences are (i) distinct and (ii) identical. We find that the pairwise interaction energies of distinct and identical Gaussian coils are both isotropic and exhibit the same decay behavior for separations larger than their gyration radius, in contradistinction to the orientationally anisotropic interaction energies of distinct and identical stiff polymers. For both Gaussian coils and stiff polymers, the attractive interaction between identical polymers is enhanced if the polarizability sequence is more heterogeneous.

Size and temperature dependence of hydrocarbon solubility in concentrated aqueous solutions of urea and guanidine hydrochloride

2002 ◽  
Vol 80 (4) ◽  
pp. 388-400 ◽  
Author(s):  
Giuseppe Graziano
Keyword(s):  
Temperature Dependence ◽  
Interaction Energy ◽  
Guanidine Hydrochloride ◽  
Van Der Waals ◽  
Hydrophobic Hydration ◽  
Van Der Waals Interaction ◽  
Threshold Size ◽  
Aqueous Urea ◽  
Work Of Cavity Creation ◽  
The Difference

At 25°C, methane and ethane are more soluble in water than in 7 M aqueous urea or 4.9 M aqueous guanidine hydrochloride (GuHCl); the reverse is true for larger hydrocarbons. In addition, the hydrocarbon solubility in 7 M aqueous urea or 4.9 M aqueous GuHCl increases compared with that in water on raising the temperature in the range of 5–45°C. These experimental data have not yet been rationalized. Using a well-founded theory of hydrophobic hydration, the present analysis indicates that the transfer of hydrocarbons from water to 7 M aqueous urea or to 4.9 M aqueous GuHCl is favored by the difference in the solute–solvent van der Waals interaction energy, and contrasted by the difference in the work of cavity creation. At room temperature, on increasing the hydrocarbon size, the first contribution rises in magnitude more rapidly than the second contribution, accounting for the threshold size occurrence. Moreover, the second contribution decreases in magnitude with an increase in temperature, becoming less unfavorable, while the first contribution is practically constant in the range of 5–45°C. The different temperature dependence of the work of cavity creation in such solvent systems is due to the fact that the density of 7 M aqueous urea and 4.9 M aqueous GuHCl decreases more rapidly than that of water when raising the temperature. The relationship between the density of a liquid and the work to create a cavity in it is discussed in detail.Key words: work of cavity creation, solute-solvent van der Waals interaction energy, H-bond reorganization.

INTERACTION BETWEEN COLOUR-SINGLET HADRONS FROM NONPERTURBATIVE QCD

1990 ◽  
Vol 05 (19) ◽  
pp. 3787-3799
Author(s):  
ROLAND C. WARNER ◽  
G.C. JOSHI
Keyword(s):  
Nonperturbative Effects ◽  
Perturbative Qcd ◽  
Atomic Physics ◽  
Van Der Waals ◽  
Van Der Waals Interaction ◽  
Many Body ◽  
Qcd Vacuum ◽  
Dilute Gas ◽  
Nonperturbative Qcd ◽  
Nontrivial Topology

We present a nonperturbative QCD contribution to interactions between separated coloursinglet hadrons, arising from the nontrivial topology of the QCD vacuum. We have calculated the effect of the structure of the vacuum (modelled here as a dilute gas of instantons) on hadron propagation, as a way of studying at least some nonperturbative effects. We find that a nonperturbative interaction arises which is familiar to us from our earlier studies of many-body potentials in multiquark systems. This interaction is distinct from those earlier perturbative QCD calculations which bear a direct analogy to the van der Waals interaction of atomic physics.

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