Flow birefringence at the sol-gel transition

J.-F. Joanny

The information provided by a flow birefringence experiment at the sol-gel transition in the sol phase is discussed There are two competing effects : cluster rotations, and cluster elastic deformation. In a steady state, rotational effects turn out to be dominant. For small velocity gradients S we predict an extinction angle x such that π/4 - x diverges with an exponent roughly equal to 3.4 i.e. a very strong effect In the vicinity of the transition, the birefringence Δn has the same divergence as the macroscopic viscosity.

Mots clés: flow birefringence; gels; non Newtonian flow; polymer solutions; sols

Domaines: Articles anciens

J.-F. Joanny. Flow birefringence at the sol-gel transition. Journal de Physique, 1982, 43 (3), pp.467-473. ⟨10.1051/jphys:01982004303046700⟩. ⟨jpa-00209415⟩