Capillary breakup extensional electrorheometry (CaBEER)

Abstract

A new electrorheological cell for the capillary breakup extensional rheometer (HaakeTM CaBER 1TM, Thermo Scientific) allowing the analysis of the rheological properties of complex fluids under the simultaneous application of an extensional flow and an electric field has been developed and tested. In this study, the add-on is described in full detail and different cornstarch suspensions in olive oil are characterized under different stretching conditions with and without an electric field. The results show that, under extensional flow and no electric field, the sample behaves as a Newtonian-like fluid, showing a linear relationship between time and filament minimum diameter. However, when the external electric field is imposed, the filament thinning process delays increasing the breakup time. If the external electric field is further increased, then the filament may even not break, depending on the imposed voltage, the Hencky strain, and the concentration of particles in the fluid sample.