Controlling Contact Electrification with Photochromic Polymers

Charge switching: Control of contact electrification was achieved using a combination of photoreactive polymers and light. Upon UV irradiation, polymers substituted with photochromic spiropyrans reversibly switch their rate, and depending on chemical structure, their sign of charging by contact electrification (see picture). Consistent with empirical predictions, these photochromic polymers tended to charge positively upon irradiation with UV light.