Critical and near critical phase behaviour and interplay between the thermodynamic Casimir and van der Waals forces in confined non-polar fluid medium with competing surface and substrate potentials

Abstract

We study the behavior of the critical Casimir force and its interplay with the van der Waals force acting between two parallel slabs separated at a distance $L$ from each other confining a non-polar simple fluid or a binary liquid mixture. The surfaces of the slabs are coated by thin layers exerting strong preference to the liquid phase of the fluid, or one of the components of the mixture. The slabs influence the fluid by long-range competing dispersion potentials. Under such conditions one usually expects {\it attractive} Casimir force governed by universal scaling function to which the dispersion potentials provide only corrections to scaling. We demonstrate, however, that below a given $L<L_{\mathrm{crit}}$ the competition between the effects due to the coatings and the slabs can result in {\it sign change} of the Casimir force when one changes the temperature $T$, the chemical potential of the fluid $\mu$, or $L$. The last implies that by choosing specific materials for the slabs, coatings and the fluid for $L\lesssim L_{\mathrm{crit}}$ one can realize {\it repulsive} Casimir force with {\it non-universal} behavior which, upon increasing $L$, gradually turns into an {\it attractive} one described by an {\it universal} scaling function for $L\gg L_{\mathrm{crit}}$. We presented arguments and relevant data for specific substances in support of the experimental feasibility of the predicted behavior of the force.

22 pages, 9 figures, 2 tables

References in corpus (37)

• Quantum magnetism and criticality
• Casimir forces between arbitrary compact objects
• Quantum Criticality
• Casimir forces in a T operator approach
• The Casimir effect: from quantum to critical fluctuations
• Casimir-Lifshitz force out of thermal equilibrium
• Universal scaling functions of critical Casimir forces obtained by Monte Carlo simulations
• Critical Casimir force in ${}^4$He films: confirmation of finite-size scaling
• Monte Carlo simulation results for critical Casimir forces
• Experiment and theory in the Casimir effect
• The thermodynamic Casimir force: A Monte Carlo study of the crossover between the ordinary and the normal surface universality class
• Thermodynamic Casimir effect for films in the 3D Ising universality class: Symmetry breaking boundary conditions
• Crossover from Attractive to Repulsive Casimir Forces and Vice Versa
• Thermodynamic Casimir effects involving interacting field theories with zero modes
• Aspect-ratio dependence of thermodynamic Casimir forces
• Control of the Casimir Force Using Semiconductor Test Bodies
• Thermodynamic Casimir Forces between a Sphere and a Plate: Monte Carlo Simulation of a Spin Model
• Interplay of critical Casimir and dispersion forces
• Quantum Critical Paraelectrics and the Casimir Effect in Time
• Critical Casimir forces steered by patterned substrates
• The Casimir effect in the nanoworld
• Critical Casimir forces and adsorption profiles in the presence of a chemically structured substrate
• Fluctuation-induced forces in periodic slabs: Breakdown of epsilon expansion at the bulk critical point and revised field theory
• Finite size behaviors of critical Ising model on a rectangle with free boundaries
• Solvation force for long ranged wall-fluid potentials
• Exact thermodynamic Casimir forces for an interacting three-dimensional model system in film geometry with free surfaces
• An experimental apparatus for measuring the Casimir effect at large distances
• Casimir-Polder interaction for gently curved surfaces
• Casimir force in O(n) lattice models with a diffuse interface
• The derivative expansion approach to the interaction between close surfaces
• Critical Casimir force in slab geometry with finite aspect ratio: analytic calculation above and below $T_c$
• Scaling of solvation force in 2D Ising strip
• Crossover from Goldstone to critical fluctuations: Casimir forces in confined O$(\mathbf{n})$ symmetric systems
• Casimir attractive-repulsive transition in MEMS
• Finite-size effects on the behavior of the susceptibility in van der Waals films under $+,+$ boundary conditions
• Thermodynamic Casimir Effect in Films: the Exchange Cluster Algorithm
• Finite-size effects in presence of gravity: The behavior of the susceptibility in ${}^{3}He$ and ${}^{4}He$ films near the liquid-vapor critical point