Enhanced Triboelectric Nanogenerators via Phase Separation of Florine-Rich Polymers from Sulfur-Rich Polymers

초록

High electron affinity (EA) of negative triboelectric materials is strongly correlated with the enhancement of triboelectric nanogenerators (TENGs). Backbone of conventional negative polymers for TENG comprises carbon (EA= ?122 kJ/mol) for example polytetrafluoroethylene (PTFE). In order to design an extremely negative triboelectric material, we previously reported sulfur-backbone polymers (EA of S= ?200 kJ/mol) with direct surface fluorination (EA of F= ?322 kJ/mol). However, this direct surface fluorination requires the use of highly reactive, explosive, and hazardous fluorine gas. In this study, we introduce a toxic-gas-free strategy for high fluorine concentration on the surface of a polymer blend film through phase separation of the fluorine-rich polymers from the sulfur-rich polymer matrices. By hot-press processing, physically mixed fluorine-rich polymers are migrated to the hydrophobic air interface, thereby capable of an increase in the surface coverage of fluorine of the blend films. The blend film-based TENGs achieve 8-fold and 9-fold higher voltage and current outputs, respectively, than those of PTFE-based TENG with a similar film thickness.