Publications [#10205] of Linda B. Smolka

Papers Submitted

1. L. B. Smolka and A. Belmonte, Effects of salt on filament dynamics during drop pinch-off in xanthan gum solutions, Phys. Fluids , submitted 2001
   (last updated on 2002/03/20)

   Abstract:
   We experimentally investigate pendant drops of non-Newtonian fluid falling in a gravitational field, and report the effects of semi-dilute concentrations of the polymer xanthan gum mixed in 80:20 glycerol/water. Our results demonstrate the macroscopic consequences of charge screening in extensional flows of polyelectrolyte polymer solutions. We find the addition of xanthan gum and potassium chloride (KCl) to the glycerol/water solution produces dramatic effects: when 780 ppm xanthan gum is added the drop length just before pinch-off increases by two orders of magnitude. This length then is decreased by as much as an order of magnitude as KCl is added. We relate this to a known molecular transition in xanthan gum driven by charge screening of its self-repulsion.