Electric rain can eat through metal

New research published in Nature reveals that raindrops become electrified as they slide down smooth surfaces, causing metal corrosion. Physicist Hans-Jürgen Butt from the Max Planck Institute for Polymer Research in Germany led the study and discovered that this phenomenon helps explain why rain corrodes metals even if they have protective coatings.

Butt and his team tested water droplets on various surfaces and a copper plate with a Teflon coating, observing the droplets burrowing into the metal, creating pits. The water droplets acquire a positive charge while the metal plate becomes negatively charged as they approach, leading to an electric field that eventually breaks down the metal.

The study suggests that charged rain droplets can help explain why corrosion sometimes fails in industrial solutions despite proper application. Materials scientist Preet Singh from the Georgia Institute of Technology, who was not involved in the research, believes that understanding this mechanism could lead to better corrosion control, saving money and lives in the long run.