Low temperature pyrolysis of polyimide films in air

Carbon films were prepared from polyimide (PI) films by heat-treatment at low temperature in air. Porous pyrolyzed films were obtained by maintaining the PI films at 500 ∼ 560 °C for 10 min in air. It was shown that heat-treatment in air is advantageous for the production of porous films with low energy and low cost. Furthermore, the pore size of the films was distributed between 1 nm and 6 nm, having not only micropores but also mesopores. This is very different from material produced by heat-treatment in nitrogen between 700 °C and 900 °C, where micropores are predominantly formed. It is expected that the porous films prepared by the heat-treatment in air are useful for the adsorption of a wide range of molecules other than small molecules. 2014 (No. 262), 63–66.]