Long-range attractions between solutes in near-critical fluids

Attard, Phil; Ursenbach, Charles P.; Patey, G. N.

doi:10.1103/physreva.45.7621

Cited by 42 publications

(25 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Two alternative mechanisms have been proposed for explaining the occurrence of these forces: on one hand, the presence of air-lled nanobubbles at the solid surface drives the attraction via a bubble-driven mechanism; on the other hand, longrange correlations in the critical region or near the spinodal line could induce an extended density depletion at the surfaces which results in the attraction [8,9,10].…”

Section: Introductionmentioning

confidence: 99%

Water confined in nanopores: Spontaneous formation of microcavities

et al. 2007

View full text Add to dashboard Cite

Molecular Dynamics simulations of water conned in nanometer sized, hydrophobic channels show that water forms localized cavities for pore diameter 2.0 nm. The cavities present non-spherical shape and lay preferentially adjacent to the conning wall inducing a peculiar form to the liquid exposed surface. The regime of localized cavitation appears to be correlated with the formation of a vapor layer, as predicted by the Lum-Chandler-Weeks theory, implying partial lling of the pore.

show abstract

Section: Introductionmentioning

confidence: 99%

Water confined in nanopores: Spontaneous formation of microcavities

et al. 2007

View full text Add to dashboard Cite

show abstract

“…As far as the theoretical side is concerned, it was de Gennes who first obtained the CCF between spherical particles [53] considering a local freeenergy functional. Among the other techniques used to study the CCF in sphere-plate and sphere-sphere geometries are the Ornstein-Zernike theory [54], conformal invariance methods [55][56][57], Monte Carlo calculations [58][59][60][61][62][63][64][65][66][67], fluid-particle dynamics simulations [68,69], mean-field type [70][71][72][73][74] and density-functional [75] theory calculations combined with the Derjaguin approximation [44,[76][77][78]. Several review articles and works [8,[79][80][81][82] summarize both the experimental and theoretical results presented there.…”

Section: Introductionmentioning

confidence: 99%

Sign change in the net force in sphere-plate and sphere-sphere systems immersed in nonpolar critical fluid due to the interplay between the critical Casimir and dispersion van der Waals forces

Valchev

Dantchev

2017

Phys. Rev. E

View full text Add to dashboard Cite

We study systems in which both long-ranged van der Waals and critical Casimir interactions are present. The last arise as an effective force between bodies when immersed in a near-critical medium, say a nonpolar onecomponent fluid or a binary liquid mixture. They are due to the fact that the presence of the bodies modifies the order parameter profile of the medium between them as well as the spectrum of its allowed fluctuations. We study the interplay between these forces, as well as the total force (TF) between a spherical colloid particle and a thick planar slab, and between two spherical colloid particles. We do that using general scaling arguments and mean-field type calculations utilizing the Derjaguin and the surface integration approaches. They both are based on data of the forces between two parallel slabs separated at a distance L from each other, confining the fluctuating fluid medium characterized by its temperature T and chemical potential µ. The surfaces of the colloid particles and the slab are coated by thin layers exerting strong preference to the liquid phase of the fluid, or one of the components of the mixture, modeled by strong adsorbing local surface potentials, ensuring the socalled (+, +) boundary conditions. On the other hand, the core region of the slab and the particles, influence the fluid by long-ranged competing dispersion potentials. We demonstrate that for a suitable set of colloids-fluid, slab-fluid, and fluid-fluid coupling parameters the competition between the effects due to the coatings and the core regions of the objects involved result, when one changes T , µ or L, in sign change of the Casimir force (CF) and the TF acting between the colloid and the slab, as well as between the colloids. This can be used for governing the behavior of objects, say colloidal particles, at small distances, say in colloid suspensions for preventing flocculation. It can also provide a strategy for solving problems with handling, feeding, trapping and fixing of microparts in nanotechnology. Data for specific substances in support of the experimental feasibility of the theoretically predicted behavior of the CF and TF have been also presented.

show abstract

“…This result implies that on the spinodal line of the bulk mixture the solute± mixture system undergoes instability with long-range (in this case in® nitely long-range [5]) solute interactions for all x (i.e., irrespective of the solute±¯uid particle interactions), which is in accord with the theoretical prediction by Attard et al [5]. When the bulk mixture is not near the spinodal line, on the other hand, the solute interactions are dependent on solute±¯uid particle interactions and can become long range (not in® nitely long range) in the sense that the range is far longer than molecular dimensions.…”

Section: Resultsmentioning

confidence: 88%

“…Although the range of the force is not in® nitely long, it is far longer than molecular dimensions (e.g.,~100 nm). As the thermodynamic state of a¯uid approaches the spinodal line, the interaction between solutes immersed in this¯uid becomes longer range due to the divergence of the bulk correlation length [5]. This property, however, is not immediately applicable to the long range force mentioned above, because the force measurements are performed in water at standard temperature and pressure.…”

Section: Introductionmentioning

confidence: 90%

See 1 more Smart Citation

Long-range attractive interaction between macroparticles in a binary fluid mixture

Kinoshita¹

1998

Molecular Physics

View full text Add to dashboard Cite

In a previous paper (Kinoshita, M., Iba, S., Kuwamoto, K., and Harada, M., 1996, J. chem. Phys., 105, 7184) we analysed the interaction between macroparticles immersed in a binarȳ uid mixture using reference hypernetted chain theory. The bulk mixture treated in the analysis separates into two immiscible phases in a certain composition regime, but the thermodynamic state considered was far from the spinodal line and the mixture was stable as a single phase. The singular behaviour of the reduced density pro® les of mixture components near the macroparticle surface and the potential of mean force between macroparticles revealed in that study have been examined further. It has been found that the thickness of the surface-induced layer and the range of macroparticle interactions suddenly grow to a submacroscopic scale which is far longer than molecular dimensions (but not in® nitely long) near the singular point. The macroparticle interactions always become strongly attractive. This is a transition phenomenon and can be interpreted as`partial wetting' of one of the components accompanied bỳ partial drying' of the other. It has been pointed out that trace amounts of impurity can a ect the macroparticle interactions to a dramatic extent. For instance, the presence of trace amounts of small, nonpolar solutes in water can cause aggregation of large, hydrophobic molecules or particles.

show abstract

Long-range attractions between solutes in near-critical fluids

Cited by 42 publications

References 9 publications

Water confined in nanopores: Spontaneous formation of microcavities

Water confined in nanopores: Spontaneous formation of microcavities

Sign change in the net force in sphere-plate and sphere-sphere systems immersed in nonpolar critical fluid due to the interplay between the critical Casimir and dispersion van der Waals forces

Long-range attractive interaction between macroparticles in a binary fluid mixture

Contact Info

Product

Resources

About