Molecularly programmed hierarchical self-assembly of bottlebrush polymers into core–shell nanospheres with intrinsic charge-trapping for high performance triboelectric nanogenerators

Abstract

We present a solution-processed bottlebrush polymer, PNB-g-PVDF [(polynorbornene)-g-(polyvinylidene fluoride)], that self-assembles into hierarchical core–shell nanospheres to achieve outstanding triboelectric performance. A thermally decomposable molecular splint, butadiene sulfone (BDS), is used to crystallize the PVDF side chains almost exclusively in the highly polar β-phase. TEM, SAED, and depth-profile XPS confirm a core–shell structure comprising a fluorine-rich, highly polar shell wrapped around a mixed PNB/PVDF core. Crucially, isothermal surface potential decay (ISPD) analysis reveals that the hierarchical bottlebrush architecture provides more stable charge-trapping environments than the corresponding linear PVDF controls, thereby suppressing charge dissipation over the measured time window. When paired with nylon-6,6 in a triboelectric nanogenerator (TENG), the film produces V_OC = 188 V, I_SC = 18.8 µA and P_max = 0.255 mW cm⁻². This output is approximately three times higher than that of a comparable β-phase linear PVDF control and is sufficient to directly power 27 commercial LEDs. These results establish bottlebrush polymer self-assembly as a promising molecular design platform for additive-free, high-performance TENG materials.