Instability of a polymeric thread

When a liquid containing a dilute solution of long, flexible polymers breaks up under the action of surface tension, it forms long threads of nearly uniform thickness. However, at a thickness in the order of microns, the thread becomes unstable to the formation of a non-uniform "blistering" pattern: tiny drops separated by threads of highly concentrated polymer solution.We show that standardmodels for the coupling between stress and polymer concentration lead to a linear instability, which exhibits very strong transient growth of the free surface perturbation. A high concentration of polymer remains in the thread part of the structure.