Colloids immersed in a critical binary liquid mixture are subject to critical Casimir forces (CCFs) because they confine its concentration fluctuations and influence the latter via effective surface fields. To date, CCFs have been primarily studied in thermodynamic equilibrium. However, due to the critical slowing down, the order parameter around a particle can easily be perturbed by any motion of the colloid or by solvent flow. This leads to significant but largely unexplored changes in the CCF. Here we study the drag force on a single colloidal particle moving in a near-critical fluid mixture and the relative motion of two colloids due to the CCF acting on them. In order to account for the kinetic couplings among the order parameter field, the solvent velocity field, and the particle motion, we use a fluid particle dynamics method. These studies extend the understanding of CCFs from thermal equilibrium to nonequilibrium processes, which are relevant to current experiments, and show the emergence of significant effects near the critical point.

Nonequilibrium Critical Casimir Effect in Binary Fluids / Furukawa, A; Gambassi, Andrea; Dietrich, S; Tanaka, H.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 111:5(2013), pp. 055701.1-055701.5. [10.1103/PhysRevLett.111.055701]

Nonequilibrium Critical Casimir Effect in Binary Fluids

Gambassi, Andrea;
2013-01-01

Abstract

Colloids immersed in a critical binary liquid mixture are subject to critical Casimir forces (CCFs) because they confine its concentration fluctuations and influence the latter via effective surface fields. To date, CCFs have been primarily studied in thermodynamic equilibrium. However, due to the critical slowing down, the order parameter around a particle can easily be perturbed by any motion of the colloid or by solvent flow. This leads to significant but largely unexplored changes in the CCF. Here we study the drag force on a single colloidal particle moving in a near-critical fluid mixture and the relative motion of two colloids due to the CCF acting on them. In order to account for the kinetic couplings among the order parameter field, the solvent velocity field, and the particle motion, we use a fluid particle dynamics method. These studies extend the understanding of CCFs from thermal equilibrium to nonequilibrium processes, which are relevant to current experiments, and show the emergence of significant effects near the critical point.
2013
111
5
1
5
055701
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.055701
https://arxiv.org/abs/1306.6745
Furukawa, A; Gambassi, Andrea; Dietrich, S; Tanaka, H.
File in questo prodotto:
File Dimensione Formato  
44-PRL.111.055701.pdf

non disponibili

Tipologia: Versione Editoriale (PDF)
Licenza: Non specificato
Dimensione 1.56 MB
Formato Adobe PDF
1.56 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/11815
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 54
  • ???jsp.display-item.citation.isi??? 55
social impact