Spreading laws for liquid polymer droplets : interpretation of the « foot » - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal de Physique Lettres Année : 1984

Spreading laws for liquid polymer droplets : interpretation of the « foot »

Résumé

Depending upon the nature of the polymer-substrate system, it has been observed that the shape of a spreading polymer droplet on a flat surface could be either a spherical cap — as for low viscosity liquids — or a spherical cap with a projecting macroscopic « foot ». We interpret this « foot » by an effect of finite slip of the polymer liquid at the surface : the existence of a large extrapolation length (b) for the velocity field of polymeric liquids near a smooth surface was predicted long ago by one of us. We calculate the detailed shape of the foot, and show that the foot thickness is comparable to b ; this length may reach very high values (> 100 microns) for entangled polymers. On the other hand, if the surface is rough, or if some chains are strongly bound to it, b is drastically reduced : this explains why the existence of the « foot » depends on the precise conditions at the surface.
Fichier principal
Vignette du fichier
ajp-jphyslet_1984_45_12_597_0.pdf (550.3 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt

Dates et versions

jpa-00232387 , version 1 (04-02-2008)

Identifiants

Citer

F. Brochard, P.-G. de Gennes. Spreading laws for liquid polymer droplets : interpretation of the « foot ». Journal de Physique Lettres, 1984, 45 (12), pp.597-602. ⟨10.1051/jphyslet:019840045012059700⟩. ⟨jpa-00232387⟩

Collections

CNRS CDF AJP PSL
47 Consultations
849 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More