Modulation of polymer surface chemical bonding and adhesion via oxygen plasma for enhanced triboelectric output performances

초록

Triboelectric nanogenerators (TENGs) have attracted significant attention for energy harvesting. Their operation is governed by contact electrification (CE), which is highly sensitive to the surface properties of triboelectric materials. Although plasma treatment is widely used for surface modification, its coupled chemical and morphological effects obscure the underlying CE mechanisms. Here, we investigate the effects of O2-plasma treatment on three polymers with distinct carbon–side-group bonding configurations: polyethylene (PE, C–H), poly(vinyl chloride) (PVC, partially substituted C–Cl), and poly(tetrafluoroethylene) (PTFE, fully substituted C–F). Under mild O2 plasma conditions, PE and PVC undergo progressive surface oxidation with increasing treatment time, arising from their relatively weak C–H and C–Cl bonds, leading to increased surface polarity and enhanced charge transfer in CE. In contrast, PTFE, which possesses strong C–F bonds, exhibits different behavior, where plasma-induced adhesion and energy dissipation associated with surface smoothing dominate the CE process and TENG output rather than polarity modification. However, under higher plasma power, excessive surface etching and corrugation degrade the TENG output for all three polymers. These results reveal that bonding-dependent plasma–surface interactions determine whether chemical polarity or interfacial adhesion governs CE, providing mechanistic insight and design guidelines for rational TENG surface engineering. © 2026 Elsevier B.V.

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