Eur. Phys. J. E 2, 359-365
Viscosity critical behaviour at the gel point in a 3d lattice model
E. Del Gado1 - L. de Arcangelis2 - A. Coniglio1
1 Dipartimento di Scienze Fisiche, Università di Napoli
"Federico II'', INFM Sezione di Napoli, Mostra d'Oltremare pad.
19, 80125 Napoli, Italy
2 Dipartimento di Ingegneria
dell'Informazione, Seconda Università di Napoli, INFM Sezione di
Napoli, via Roma 29, 81031 Aversa (Caserta), Italy
antonio.coniglio@na.infn.it
Received 20 December 1999 and Received in final form 18 February 2000
Abstract
Within a recently introduced model based on the
bond-fluctuation dynamics, we study the viscoelastic behaviour of a
polymer solution at the gelation threshold. We here present the
results of the numerical simulation of the model on a cubic
lattice: the percolation transition, the diffusion properties and
the time autocorrelation functions have been studied. From both the
diffusion coefficients and the relaxation times critical behaviour
a critical exponent k for the viscosity coefficient has been
extracted: the two results are comparable within the errors giving
,
in close agreement with the Rouse model prediction and
with some experimental results. In the critical region below the
transition threshold the time autocorrelation functions show a long-time
tail which is well fitted by a stretched exponential decay.
PACS
05.20.-y Classical statistical mechanics
- 82.70.Gg gels and sols
- 83.10.Nn Polymer dynamics
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
