Long-ranged correlations in a fluid close to its critical point Tc cause distinct forces between immersed colloidal particles and the container walls. We calculate such a force and its temperature dependence for the generic case of a spherical particle located at a distance D from a planar wall and find that the force attains a maximum at a temperature Tmax(D) above Tc, which facilitates quantitative experimental tests. The corresponding effective pair interaction between the colloidal particles themselves, potentially leading to aggregation, is also discussed.
Hanke, A., et al. “Critical Casimir Forces between Spherical Particles in Fluids.” Physical Review Letters, vol. 81, no. 9, American Physical Society, Aug. 1998, pp. 1885–88, doi:10.1103/PhysRevLett.81.1885.
Physical Review Letters