Spherical porous framework of calcium carbonate prepared in the presence of precursor PS–PAA as template

Spherical calcium carbonate composite of 5–6 μm in diameter was firstly prepared using the PS–PAA (polymer of polystyrene and poly(acrylic acid)) as template. Porous calcium carbonate spheres with calcite structure were then obtained by a slow heating rate of 1 °C min−1 calcination process in air. The morphology and structure of the as-prepared products were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and Thermo-Gravimetric/Differential Thermal (TG–DTA) methods. Nitrogen sorption measurements revealed that the obtained products exhibited high BET surface area of 42.88 m2 g−1 and average pore size of 20.10 nm. For comparison, a common heating rate of 10 °C min−1 calcination process was carried out. Only CaCO3 grains with high dispersion existed.