Using simulations and scaling methods, the effect of an electric field on a collapsed polyelectrolyte globule is investigated, where conduction by counterions and the polyelectrolyte itself is taken into account. At a critical field $E^{*}$, a nonequilibrium transition occurs at which the polyelectrolyte unfolds and aligns parallel to the external field. $E^{*}$ is determined using scaling results for the polarizability of a polyelectrolyte globule and exhibits a dependence on the chain length $N$, $E^{*}\sim N^{-1/2}$, which might be useful for electrophoretic separation of charged biopolymers.

• Received 6 September 2002

DOI:https://doi.org/10.1103/PhysRevLett.90.128104