From Waste to Functional Materials: A Multifunctional Electromagnetic Interference Shielding Composite from Waste Rock Wool

Electromagnetic interference (EMI) shielding materials are effective in eliminating unwanted electromagnetic interference and reduce the potential harm to human health. Among them, the EMI shielding materials fabricated from wastes but with multiple functions are particularly attractive. However, it is always a great challenge to integrate multiple functions into one EMI shielding material, especially when using the wastes as raw materials. Here, a multifunctional EMI shielding composite was fabricated from waste rock wool, which is one of the fast-growing solid wastes in the world. The waste rock wool was converted into a valuable EMI material by simply dip-coating the rock wool into a graphene oxide aqueous dispersion and a following chemical reduction by hydrazine hydrate. The obtained rock wool/reduced graphene oxide (RW-rGO) composites showed excellent EMI shielding performance (>25 dB) and good hydrophobicity (water contact angle >130°). Moreover, the RW-rGO composites exhibit good thermal insulation and fire-retardant ability. We believe that the strategy for fabricating RW-rGO composites not only provides an effective way to solve the problem of waste rock wool pollution but also can promote the large-scale manufacturing of multifunctional EMI shielding materials.