A stage-based framework for closed-loop recycling of polymeric composite membranes.

Abstract

Polymeric composite membranes are essential in modern separation technologies but pose critical challenges for sustainable end-of-life (EOL) management due to their chemically heterogeneous, multilayer structures. Existing approaches, such as mechanical processing or catalytic depolymerization, exhibit limited efficiency in separating and recovering multiple components. Here, we present a stage-based physical-chemical recycling strategy enabling multicomponent recovery and closed-loop regeneration of composite membranes through sequential solvent extraction, catalytic depolymerization, and membrane recasting. Using real EOL membranes as feedstock, the process yields regenerated membranes with mechanical robustness and separation performance comparable to commercial counterparts. Life-cycle assessment and technoeconomic analysis reveal substantial reductions in environmental impacts and material costs relative to conventional membrane manufacturing. By engineering a scalable process system for the circular recovery of complex membrane components, this work bridges materials science and process engineering, offering a viable route for sustainable management of polymeric composite waste streams.