(364e) Contact Electrification of Natural and Synthetic Polymers: The Role of Material Strain

It is well known that insulating materials can build up static charge when they are rubbed together, referred to as contact electrification or triboelectric charging.  Classically, one thinks of rubbing an inflated balloon on hair or socks on a carpet.  This phenomenon also manifests itself in a number of real-world circumstances, such as polymer synthesis where static charging of the powder leads to catastrophic effects such as plating of the reactor walls.  Despite a general familiarity, the fundamental mechanism behind triboelectric charging remains poorly understood.  We have recently found that strain in material can lead to interesting effects in the charging behavior of polymeric materials¹.  To study the effect of strain, a latex rubber material is stretched by inflating and contacted with Teflon.  The charge on the Teflon is found to vary and even reverse in polarity depending on the magnitude of strain in the latex.    We have found similar effects in other polymeric materials such as Teflon and Nylon, suggesting that the importance of strain in contact electrification is universal.

 1. M. Sow, R. Widenor, A. Kumar, S. W. Lee, D. J. Lacks, and R. M. Sankaran, “Strain-induced reversal of charge transfer in contact electrification,” Angew. Chem. Int. Ed. 51, 2695 (2012).