Coassembly of hybrid microscale biomatter for robust, water-processable, and sustainable bioplastics.

Unlike conventional methods that typically involve extracting biopolymers/monomers from biomass using lots of hazardous chemicals and high energy, the direct utilization of biological matter (biomatter) without extraction offers a more sustainable alternative for bioplastic production. However, it often suffers from insufficient mechanical performances or limited processabilities. Herein, we proposed a hybrid microscale biomatter coassembly strategy that leverages the interactions between the inherent microarchitectures of waste cotton fiber and pollen particles. With minimal preprocessing, they form a castable slurry that can spontaneously organize into a dense fiber-laminate bioplastic network, exhibiting high mechanical properties (52.22 megapascals and 2.24 gigapascals) without using toxic organic chemicals or heavy machinery. The resulting bioplastic features controlled hydration-induced microstructural disassembly/reassembly, enabling water-based processability into complex, dynamic architectural systems. In addition, it demonstrates good biodegradability, closed-loop recyclability, and satisfactory environmental benefits, outperforming most common plastics. This study provides an instant nature-derived paradigm for bioplastics' sustainable production, processing, and recycling, offering a promising solution for facilitating eco-friendly advanced applications.