Precise chemical regulation of polar groups to enhance the charge transfer density of cellulosic triboelectric textiles

Abstract

Cellulose has a wide range of sources in nature and is one of the main components of natural recycled materials, such as cotton, hemp and bamboo. However, due to the electrical neutrality and weak dielectric properties of cellulose, the mechano-electric conversion efficiency and charge transfer density of cellulosic triboelectric textiles are relatively low, making it difficult to meet the practical power supply and self-powered sensing requirements. Here, through precise chemical grafting methods, amino and fluorine functional groups are introduced onto the cellulose macromolecular chains of traditional cotton fabrics to enhance their electron-donating and electron-withdrawing abilities, respectively. Furthermore, a cellulosic triboelectric textile with high charge transfer ability is developed using aminosilane-grafted fabric and fluorosilane-grafted fabric as contact layers, which can increase the transfer charge density to 2.5 times that of the unmodified fabric. It is noteworthy that the modified cellulosic cotton fabric not only does not change its crystallization and mechanical properties, but also maintains its original washability and stability. The output power density of the modified cellulosic triboelectric textile reaches 6.08 mW m⁻² at an external resistance of 300 MΩ, which can simultaneously light 60 LEDs and continuously power miniature electronic devices. In summary, this work proposes a novel strategy based on precise control of cellulose electrification polarity to improve the triboelectric output performance, which is of great significance for optimizing the mechano-electric conversion ability of non-polar or weak-polar materials.