Flexible, large area preparable phase change PVA/P(ILs-AM)/SSD films for electromagnetic wave absorption and infrared stealth

Electromagnetic wave absorption (EMA) and infrared stealth are two vital ways of anti-detection that it is a great challenge to develop a compatible material which is low-cost, easy to prepare and exhibits excellent mechanical properties. Here, multifunctional films are prepared using one-pot method by wrapping phase change crystals Na₂SO₄·10H₂O (SSD) with dual-network molecular chains. The phase change behavior with high enthalpy (150.8 J/g) at a temperature of 31.2°C can absorb and release latent heat, which endows films with the ability to regulate temperature dynamically. The dual-network acts as phase change buffer-medium to prevent leakage, with excellent mechanical properties, and also provides abundant conductivity and polarization loss. The results show that the films significantly reduce thermal radiation temperature of the target in low-medium temperatures while achieving excellent EMA properties (the effective absorption bandwidth reaches 6 GHz at 1.9 mm). It provides an idea for the development of multi-band compatible functional materials.