SPP 2171 Spring Conference: Dynamic Wetting of Flexible, Adaptive, and Switchable Substrates

Electrostatic charge separation at receding contact lines, called slide electrification, has been extensively studies in recent years. 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 surfaces and find a substantial influence of electrostatic charge separation. First, electrostatic interactions lead to 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 electrostatic 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.