Enhancement of the Triboelectric Properties of a Polymer Fiber Membrane by Ultrapure Water

Enhancing the charge density and stability of triboelectric materials is essential for developing high-performance triboelectric nanogenerators (TENGs). In this work, a simple enhancement strategy based on ultrapure water treatment is proposed to improve the triboelectric performance of polymer fiber membranes. Unlike previously reported water-assisted modifications or conventional electret charging, the proposed UWE strategy achieves deep charge trapping through spontaneous, ion-free liquid-solid contact electrification, fundamentally avoiding both ion-induced charge screening and external high-voltage fields. Under optimized conditions, the transfer charge and open-circuit voltage of the ultrapure-water-treated polypropylene sample (UWE-PP) reach 305.24 nC and 3.19 kV, respectively, while the transfer charge increases by about 161.2% compared with untreated PP. The treated fiber membranes also show improved charge retention, allowing the devices to maintain stable triboelectric output during long-term operation. The water-treated membranes further exhibit superior performance under humid conditions compared with conventional corona-charged samples, indicating stronger resistance to moisture-induced charge dissipation. At a relative humidity of 80%, the UWE strategy increases the transfer charge of PP, poly(vinylidenefluoride), and polystyrene by approximately 597.1%, 57.1%, and 733.5%, respectively. Overall, this environmentally friendly and simple method provides an effective strategy for enhancing the electrical performance of polymer-based TENGs, particularly for applications requiring improved humidity tolerance and long-term operational stability.