Triple kill: Fabrication of composites coming from waste face masks, polystyrene microplastics, graphene, and their electromagnetic interference shielding behaviors

Conducting polymer composites possessing excellent electromagnetic interference shielding effectiveness (EMI SE) are effective methods to prevent the harm caused by electromagnetic pollution. Since COVID-19 in 2019, people have made a lot of progress in the recycling of waste face masks (FMs). Besides, effective measures are needed to reduce the harm of microplastics (MPs) pollution in the water environment. However, so far, no publications are available in the literature that simultaneously solve the problem of electromagnetic pollution, FM pollution, and MP pollution. Herein, FMs, polystyrene MPs (PS MPs), and graphene (Gr) were used to fabricate EMI shielding composites with isolated conductive network structures via the adhesion of polydopamine (PDA). The effects of isolated conductive networks, different sizes of PS MPs, and different layers of FMs on the adsorption properties of FMs-PDA-Gr, as well as electrical performance for the obtained polypropylene-PDA-Gr composites, were studied. The composites displayed EMI SE for 29.3 dB in X-band with 2 vol.% Gr content due to the isolated conductive network structure, which may be useful to the simultaneous elimination of garbage from electromagnetic pollution, FMs pollution, and MPs pollution to a certain degree.