Surface properties of porous carbons obtained from polystyrene-based polymers within inorganic templates: role of polymer chemistry and inorganic template pore structure

Three inorganic adsorbents were applied as templates to produce porous carbons from polystyrene-based organic polymers. As matrices, amorphous silica gel, mesoporous alumina and microporous zeolite 13X were used. Organic precursors were polystyrene sulfonic acid (co-maleic acid) sodium salt and polystyrene co-maleic acid isobutyl/methyl mixed ester. The impregnated templates were carbonized at 800 °C. After removal of inorganic matrices porous carbons were obtained. Materials were characterized by adsorption of nitrogen, thermal analysis, potentiometric titration and SEM. Owing to the template carbonization, highly mesoporous carbons were obtained (SBET up to 1500 m2/g, Vt up to 3 cm3/g) with majority of pores with sizes between 20–200 Å. Although the carbons were not replicas of their matrices, the carbonization within the confined space with utilization of self-released pore formers resulted in unique carbonaceous materials with very acidic surface. That acidity is linked to either exothermic effect of sodium reactivity with moist air or susceptibility for air oxidation of small graphene layers formed in the confined pore space.