Design of Hyperbranched CNF-Grafted Vegetable Oil Polymer Electrospun Membranes for Sensitive Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) from bioderived polymers offer a sustainable route for energy harvesting. Specifically, vegetable oil-based polymers (VOPs) combine renewability with flexibility, yet their high viscosity and poor mechanical strength have impeded the fabrication of robust, high-surface-area architectures essential for efficient devices. To overcome this, we designed a hyperbranched one-component nanocomposite (HOCN) by covalently grafting VOP chains onto cellulose nanofibrils (CNFs). By enabling the stable electrospinning of high-oil-content VOPs, the HOCN architecture concurrently addresses key processing challenges: reducing viscosity, enhancing conductivity, and reinforcing the network. Consequently, the resulting membranes exhibit a tensile strength of 0.6 ± 0.1 MPa and a toughness of 2.6 ± 0.3 MJ/m3, a nearly 6-fold improvement over pure PLT membranes. Integrating carbon nanotubes (CNTs) into this network produces a flexible, self-supporting triboelectric layer that couples efficient charge induction with rapid electron transport. The optimized HOCN/CNT-based TENG delivers a maximum output of 365 nA and 5.32 V (3 Hz, 4 × 4 cm2) and functions reliably as a pressure sensor, with voltage response proportional to finger pressure and stable performance over 10,000 cycles. By addressing the longstanding processing and performance challenges of vegetable oil polymers, this study demonstrates the potential of biobased HOCN/CNT composites for self-powered sensing systems and sustainable energy applications.