Random nano-structuring of PVA/MXene membranes for outstanding flammability resistance and electromagnetic interference shielding performances

Nowadays, highly flexible, ultrathin, and conductive polymer composites are exceptionally desirable for electromagnetic interference shielding (EMI) applications due to their unique mechanical strength and electrical and flame-resistant properties. While the traditional nanocomposites blending remains the mainstream method to fabricate polymer/inorganic composites, it results in poor electrical conductivity caused by the discontinuous connection of conductive network as well as the unsatisfactory mechanical strength limiting the further practical applications. Herein, we introduce a facile and practical methodology involving the fabrication of selfinterlocked poly (vinyl alcohol) (PVA) and conductive Ti3C2Tx MXene networks, then combining them to construct a nanostructure-engineered PVA/MXene membrane. This membrane exhibits superior mechanical strength, in which the tensile strength is about three times higher than the control PVA. Additionally, the membrane demonstrates outstanding fire-resistant performances with an 80% reduction of peak heat release rate than pure PVA. More importantly, this unique membrane with random conductive networks possesses an outstanding EMI shielding efficiency near 41 dB much greater than traditional composite, which meets the requirement of high-efficiency EMI shielding applications. This article displays a novel strategy to fabricate a nanostructured polymer membrane with outstanding fire resistance, electrical conductivity, and mechanical strength, targeted and designed for high-efficiency EMI shielding applications.