Adaptive two capacitor model to describe slide electrification in moving water drops

TL;DR

This paper introduces an adaptive two-capacitor model to explain slide electrification in moving water drops, capturing charge separation dynamics and polarity changes across various surfaces, providing new molecular insights.

Contribution

The paper presents a novel adaptive two-capacitor model that accurately describes slide electrification phenomena, including polarity reversal, across different surface types.

Findings

Model explains charge polarity reversal.

Captures drop-rate dependence of charge.

Provides molecular-level insights into charge separation.

Abstract

Slide electrification is a spontaneous charge separation between a surface and a sliding drop. Here, we describe this effect in terms of a voltage generated at the three-phase contact line. This voltage moves charges between capacitors, one formed by the drop and one on the surface. By introducing an adaptation of the voltage upon water contact, we can model drop charge experiments on many surfaces, including more exotic ones with drop-rate dependent charge polarity. Thus, the adaptive two capacitor model enables new insights into the molecular details of the charge separation mechanism.