Super Tough and Self-Healable Poly(dimethylsiloxane) Elastomer via Hydrogen Bonding Association and Its Applications as Triboelectric Nanogenerators

Poly(dimethylsiloxane) (PDMS) as one of the electron-drawing materials has been widely used in triboelectric nanogenerators (TENG), which is expected to generate electron through friction and required to endure dynamic loads. However, the nature of the siloxane bond and the low interchain interaction between the methyl side groups result in low fracture energy in PDMS elastomers. Here, a strategy that combined the advantages of the dynamic of hierarchical hydrogen bonding and phase-separation-like structure was adopted to improve the toughness of PDMS elastomers. By varying both stronger and weaker hydrogen bonding within the PDMS network, a series of super tough (up to 24,000 J/m²), notch-insensitive, transparent, and autonomous self-healable elastomers were achieved. In addition, a hydrophilic polymeric material (PDMAS-U10) was synthesized as the conductive layer. A transparent TENG was fabricated by sandwiching the PDMAS-U10 between two pieces of the PDMS elastomer. Despite its hydrophilic nature, PDMAS-U10 exhibit strong adhesion interaction with hydrophobic PDMS elastomers. As such, a tough (16,500 J/m²), self-healable (efficiency ∼97%), and transparent triboelectric nanogenerator was constructed. A self-powered system employing the TENG is also demonstrated in this work.