Structure and morphology of microporous carbon membrane materials derived from poly(phthalazinone ether sulfone ketone)

A novel polymeric precursor, poly(phthalazinone ether sulfone ketone) (PPESK), was used to prepare microporous carbon membranes by carbonization at 950 °C. The structure and morphology of the microporous carbon membrane materials were characterized by X-ray diffraction, Raman spectrometry, transmission electron microscopy, scanning electron microscopy and nitrogen adsorption techniques. The results illustrate that PPESK is a promising carbon membrane precursor materials, which results in well-developed microporosity after carbonization treatment. The pore structure of carbon membranes derived from PPESK consists of two kinds of pores: ultramicropore centering at 0.56 nm and supermicropore centering at 0.77 nm. Graphitic structure and turbostratic carbon coexist in the as-prepared carbon membranes, of which the interlayer d spacing, the microcrystal size La and the stacking height Lc are 0.357, 3.91 and 4.39 nm, respectively. For PPESK, the oxidative stabilization prior to the carbonization is beneficial to the preparation of the carbon membrane with high gas separation performance, which helps to shift the pore size distribution to smaller pore width and to inhibit the growth of crystallites in the carbon matrix.