Molecular Dynamics Insights into the Electrospray Behavior of Polymer Solutions

A molecular dynamics (MD) method was employed to investigate the potential influence of operating parameters on the electrospray behavior of aqueous poly(ethylene glycol) (PEG) solutions at the micro- and nanoscale. The evolution of jet dynamics, droplet generation characteristics, and energy properties on the molecular scale under varying electric field strengths and flow rates were analyzed in the present study. The results reveal that polymer solution electrospray jets exhibit diverse dynamic behaviors including winding, linking, overflow, coalescence, and rupture. Both the electric field strength and flow rate significantly affect the atomization mode of the electrospray. As the electric field strength increases, the jet transitions from multicone to single-cone mode, accompanied by changes in jet length and position. Similarly, with an increase in liquid flow rate, the jet evolves from multicone to single-cone mode and further into a single-stranded cylindrical jet, along with a marked increase in the number of droplet clusters. Moreover, the electrospray current is more sensitive to variations in flow rate, and its response time becomes longer as the flow rate increases. This study elucidates the microscopic mechanisms underlying the dynamic behavior evolution of polymer solution electrospray jets, providing a theoretical foundation for the design of complex polymer atomization media and the optimization of the electrospray process parameters.