The overlooked key factors for accurate determination of polymer triboelectric series
Triboelectrification (TE) governs charge transfer between contacting polymers, with electron transfer via electron cloud overlap as the dominant mechanism. Reliable triboelectric series are critical for mitigating electrostatic hazards and optimizing triboelectric nanogenerators (TENGs), yet current polarity rankings suffer from overlooked inconsistencies in polymer film properties. This perspective identifies three key factors undermining accuracy: purity, surface roughness, and mass/thickness. Plasticizers such as 30 wt% glycerol in protein composite films shift measured triboelectric polarity relative to pure films, while insufficient drying of hygroscopic polymers introduces water-mediated artifacts. Surface roughness disparities, exemplified by porous cellulose versus chitosan aerogels, alter effective contact areas and distort assessments of amine versus hydroxyl contributions. Mass and thickness variations further modulate charge transfer. Standardizing these parameters—identical shape, contact area, roughness, and rigorous drying—is essential for valid triboelectric series. The analysis provides actionable protocols for researchers and engineers, emphasizing that without such controls, reported triboelectric polarities may reflect composite or geometric artifacts rather than intrinsic polymer properties, compromising material selection for TENGs and electrostatic mitigation.