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arXiv · 2610.36757

Tribocharging of Granular Materials Dictated by Geometric and Thermoelectric Effects

Donggeun Kang·Ji-Ho Mun·Seungil Baek·Jaeuk Seo·Sirichok Jungthawan·Yong Woon Kim·Yong-Hyun Kim
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Abstract

Tribocharging of granular materials is a widespread phenomenon ranging from volcanic eruptions and dust storms to pharmaceutical processing, yet its underlying mechanism remains elusive. Recent thermoelectric models have provided a quantitative framework for triboelectric charge transfer, but they have difficulty accounting for charging between identical materials. In this Letter, we propose a theory of granular tribocharging based on the interplay between particle geometry and thermoelectric response. Collision-induced frictional heating produces a size-dependent temperature asymmetry between particles, generating a thermoelectric voltage that drives charge transfer. The sign of the Seebeck coefficient determines the charging polarity, while particle size and thermal properties set its magnitude. Our multi-collision theory explains the experimentally observed size- and material-dependent reversal of charging polarity, as in quartz and nylon.

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Donggeun Kang, Ji-Ho Mun, Seungil Baek, Jaeuk Seo, Sirichok Jungthawan, Yong Woon Kim, Yong-Hyun Kim. 2026-10-27. Tribocharging of Granular Materials Dictated by Geometric and Thermoelectric Effects. https://arxiv.org/abs/2610.36757

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