Charge separation at contact lines slows down the breakup of liquid bridges on surfaces

ORAL

Abstract

Electrostatic charge separation at receding contact lines, called slide electrification, has been extensively studies in recent years. The resulting electrostatic interactions fundamentally contribute to contact angle hysteresis and can significantly slow down the movement of sliding drops. Yet, the relevance of electrostatic effects in dynamic wetting beyond single drops has largely remained obscure. Here, we experimentally study the breakup of liquid bridges on non-conductive solid substrates and find a substantial influence of electrostatic charge separation. First, electrostatic interactions lead to the spontaneous random movement of satellite drops after the liquid bridge breakup. Second, electrostatic forces slow down the dynamics of the breakup process. We find that the influence of electrostatics increases with the liquid viscosity and that our experimental observations align with slide electrification theory. Our results highlight the wider importance of slide electrification in dewetting scenarios beyond drops, even when the liquid is connected to a large reservoir.

Publication: Electrostatics slows down the breakup of liquid bridges on solid surfaces, Salar Jabbary Farrokhi, Aaron D. Ratschow, and Steffen Hardt, in preparation

Presenters

  • Aaron D Ratschow

    Technische Universitat Darmstadt, Institute for Nano- and Microfluidics, TU Darmstadt, TU Darmstadt

Authors

  • Aaron D Ratschow

    Technische Universitat Darmstadt, Institute for Nano- and Microfluidics, TU Darmstadt, TU Darmstadt

  • Salar Jabbary Farrokhi

    Technische Universität Darmstadt

  • Steffen Hardt

    Technische Universität Darmstadt, TU Darmstadt, Fachgebiet Nano- und Mikrofluidik, TU Darmstadt, 64287 Darmstadt, Germany