Polymeric filament thinning and breakup in microchannels

The effects of elasticity on filament thinning and breakup are investigated in microchannel cross flow. When a viscous solution is stretched by an external immiscible fluid, a low 100 ppm polymer concentration strongly affects the breakup process, compared to the Newtonian case. At late times when viscoelastic stresses become important, polymer filaments show much slower evolution, morphology featuring multiple connected drops, and different scaling with the ratio of flow rates. The filament thinning process can be described in terms of extensional viscosities of the immiscible fluids, which for the polymer solution includes strain hardening