The impact of electric fields on rheology and fiber formation in ElectroHydroDynamics-based manufacturing

This study investigates the impact of solution properties on the morphology of electrosprayed and electrospun polyvinylpyrrolidone (PVP) structures. PVP solutions with varying molecular weights (30 kDa, 90 kDa) and concentrations (10 wt%, 30 wt%) were prepared in dimethylformamide (DMF) and ethanol (EtOH). Despite the dominant viscous nature of PVP solutions, viscosity alone did not significantly influence final structure. Instead, solvent properties proved crucial in determining morphology. DMF’s high surface tension and boiling point inhibited fiber formation, leading to particle formation, while EtOH’s lower properties promoted fiber formation through rapid solidification. Polymer concentration also affected solvent evaporation rate and subsequent structure formation. Electrorheologycal measurements suggest polymer chain alignment within the electric field, yet overall solution behavior was dominated by viscous forces. These findings highlight the critical role of solvent properties in determining the final morphology of electrospun and electrosprayed structures.