Development of piezo-driven extensional rheometry with drop-on-demand head for dilute polymer solutions

To assess the extensional properties of viscoelastic liquids with low viscosity, we explored a method employing a piezoelectric drop-on-demand (DOD) head. This method ejected polymer solutions of dilute concentrations, which offered a higher suitability than the liquid dripping (LD) method. An exponentially decaying regime of filament diameter was observed, like the elasto-capillary regime of the LD method. The established power law relation between extensional relaxation time and polymer solution concentration holds in the dilute regime. The findings indicate that the filament decay behaviors observed for the DOD method with jetting flow and the LD method with dripping flow are comparable.