Fabrication of closed-cell polyimide inverse opal photonic crystals with excellent mechanical properties and thermal stability

Closed-cell polyimide IOPCs were fabricated using core–shell poly(styrene–methyl methacrylate–acrylic acid) colloidal spheres as a template. For comparison, open-cell polyimide IOPCs were also prepared using polystyrene colloidal spheres as a template. The polyimide IOPCs with a closed-cell structure had much better mechanical properties than those with open-cell structures. Moreover, the photonic band gap and superhydrophobicity of the closed-cell polyimide IOPCs could be maintained even after they were treated at 400 °C for 2 h. These closed-cell polyimide IOPCs were the stablest polymer photonic crystals under high temperature conditions, and would have great potential applications in thermal insulation, energy absorption and aerospace.