Universality in coalescence of polymeric fluid drops

Abstract

Coalescence of liquid droplets involves an interplay between capillary forces, viscous forces and inertial forces. Here, we unveil a universal temporal evolution of the neck radius during the coalescence of two polymeric drops. Through high speed imaging we demonstrate that drops of polyacrylamide (PAM), poly-vinyl alcohol (PVA), polyethylene oxide (PEO), polyethylene glycol (PEG) and xanthan gum (XG) depict a universal behavior $R/\sqrt{(}{\nu }_0\lambda )\sim (t/\lambda {)}^{0.36}(C/C^{\ast }{)}^{-0.83}$ over a dilute, semi-dilute and non-dilute range of concentrations. A linear Phan-Thein-Tanner viscoelastic model captures the temporal aspect of universality.

3 Figures. Soft Matter, 2020