Designing of Self‐Dispersing Soft Dendritic Microcleaners for Microplastics Capture and Recovery

Abstract The recovery of persistent microplastics (MPs) from aquatic systems is a pressing environmental issue that is hard to address by conventional methods such as filtration or centrifugation. Strategies are investigated for the design of the self‐dispersal and collection cycle of a class of active microcleaners comprising soft dendritic colloids (SDCs). The SDCs are made of chitosan and have a hierarchical fibrillar structure which enables adhesive collection of MP particles through van der Waals attraction. Wide‐scale dispersion is achieved by agglomerating the SDCs into larger supraparticles, which self‐propel on the water surface by the Marangoni effect driven by small amounts of organic oil. The cycle of propulsion, rehydration, and sinking enables efficient MP capture by the sedimenting SDCs. Further, magnesium hydrolysis reaction timed by encapsulation leads to vertical bubble propulsion and collection of the SDC‐MPs aggregates on the surface. Overall, the results present a proof of concept of the potential of comprehensive MP cleanup methods based on sustainable self‐dispersing microcleaners.