J. Phys. II France
Volume 5, Numéro 4, April 1995
Page(s) 491 - 495
DOI: 10.1051/jp2:1995145
J. Phys. II France 5 (1995) 491-495

Drag on a Tethered Chain Moving in a Polymer Melt

A. Ajdari1, F. Brochard-Wyart2, C. Gay3, P.G. de Gennes3 and J.L. Viovy1

1  ESPCI, Physico-Chimie Théorique, 10 rue Vauquelin, 75231 Paris Cedex 05, France
2  PSI, Institut P. et M. Curie, 11 rue P. et M. Curie, 75231 Paris Cedex 05, France
3  Collège de France, 1 place M. Berthelot, 75231 Paris Cedex 05, France

(Received 17 January 1995, accepted 25 January 1995)

A chain of N monomers is attached to a small colloïdal particle, and is pulled (at a velocity V) inside a polymer melt (chemically identical, with P monomers per chain). The main parameter for this problem is the number X(V) of P chains entangled with the ( N) chain. Earlier estimates of X are criticized, and a new form is proposed: at large $N(N>N^2_{\rm e})$, we are led to a "Stokes" regime, X=N1/2, while at smaller $N(N<N^2_{\rm e})$, we find a "Rouse" regime, $X=N/N_{\rm e}$ (where $N_{\rm e}$ is the number of monomers per entanglement).

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