Structural characterization of activated carbon adsorbents prepared from paper mill sludge

Small-angle neutron scattering (SANS) was used to characterize the microstructure of a series of activated carbons produced from paper mill sludge using ZnCl₂. The pores in these carbons are roughly rod-like; their radii and volumes increase with an increase in the amount of activating agent (ZnCl₂) used for the production of the carbons. Contrast-variation SANS studies demonstrate the existence of two different phases, a zinc-rich particle phase and a bulk carbon phase with nanopores. Both phases are largely accessible to the solvent. The size and morphology of the pores and inclusions were determined from the SANS data. A conceptual model describing these carbons as consisting of amorphous carbon containing zinc-rich particles in large voids linked by narrow channels is proposed.