Suppression of thermally excited capillary waves by shear flow.
We investigate the thermal fluctuations of the colloidal gas-liquid interface subjected to a shear flow parallel to the interface. Strikingly, we find that the shear strongly suppresses capillary waves, making the interface smoother. This phenomenon can be described by introducing an effective interfacial tension that increases with the shear rate. The increase of sigma(eff) is a direct consequence of the loss of interfacial entropy caused by the flow, which affects especially the slow fluctuations. This demonstrates that the interfacial tension of fluids results from an intrinsic as well as a fluctuation contribution.
Derks
Didi
D
Soft Condensed Matter, Debye Institute, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
Aarts
Dirk G A L
DG
Bonn
Daniel
D
Lekkerkerker
Henk N W
HN
Imhof
Arnout
A
D002196:Capillaries / Q000737:chemistry* / Q000502:physiology; D003102:Colloids / Q000737:chemistry*; D005740:Gases / Q000737:chemistry; D007700:Kinetics; D033081:Shear Strength; D012996:Solutions / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature
D003102:Colloids; D005740:Gases; D012996:Solutions