Kinetics of collapse for a flexible coil

If a polymer chain is transferred abruptly from θ conditions to bad solvent conditions (e.g. by a shift of temperature ΔT) it collapses with a certain characteristic time τc. We propose a scaling structure for τc, based on an « expanding sausage model », and taking into account the hydrodynamic interactions. We find that τ c ≅ τR ΔT/θ where τR is the Rouse time of the θ chain : the time τc increases with the depth of quench.