Scientists Link Coating Corrosion to Water Droplets' Slide Electrification

A Nature study shows water droplets sliding across insulators pick up charges of up to 2 nanocoulombs and trigger localized dielectric breakdown when hitting coatings. The effect gradually destroys protective layers on bridges, pipelines, car bodies and monuments.

• Droplets carry 0.2 nC on a leaf up to ~2 nC on quartz
• After 3,000 impacts, Teflon coatings showed visible damage
• Breakdown punctures the layer "like a small flash of lightning"
• Charged droplets also form in clouds, waves and waterfalls