Recycling breakthrough turns discarded Covid face masks into EV tech

Researchers from Australia and China have developed an innovative method to upcycle the vast quantities of discarded polypropylene (PP) Covid-19 face masks—estimated at over 950 billion since 2020—into high-performance nanocomposite films for electric vehicle (EV) electronics. The process involves cleaning and shredding used masks, coating the PP fibers with food-grade tannic acid to impart a negative charge, and then self-assembling positively charged graphene nanoplatelets around each fiber. A brief hot-pressing step fuses these into metre-scale films using only water and tannic acid under atmospheric pressure, making the method environmentally friendly and compatible with scalable roll-to-roll manufacturing. The resulting PP@G films exhibit exceptional thermal and electromagnetic interference (EMI) shielding properties, with thermal conductivity reaching 87 W/m·K—about 100 times higher than typical plastics—and EMI shielding effectiveness of 88 dB at 800 micrometers thickness, outperforming many advanced composites. These films can significantly