Recyclable Biophenolic Nanospheres for Sustainable and Durable Multifunctional Applications in Thermosets

Nanomaterialshave a critical role in functional materials engineering;however, their efficient recycling, durable use, and multifunctionalintegration remain a huge challenge for sustainable development. Herein,we report multifunctional biophenolic nanospheres that exploit stimuli-responsivereversible assembly based on multiple directional interactions, allowingfor closed-loop recycling and durability, even in complex systemsof thermosets. The biobased nanospheres can serve long-term in variousenvironments (high temperature, water, acid, surfactant solutions,etc.). By matching disassembly conditions, the nanospheres can becircularly dissociated into precursors, removed from application systems,reassembled, and reused sustainably. The corresponding mechanism isillustrated by experimental characterization and theoretical simulation.We further demonstrate the recycling and durable multifunctional effectsof the nanospheres in thermoset foams. The reproducible nanosphereswith diverse radical scavenging abilities endow nanocomposites withexcellent mechanical enhancement, aging resistance, and durable flameretardancy. This study paves the way for tackling the pressing issueof high-value functional nanomaterial sustainability.