| Expanded graphite (EG) is a kind of worm-like porous particle. It has been proved to perform excellent sorption performance for oils and macromolecule with its special pore structure. However, low density and fragile mechanical property have been the main hindrance to EG in its application. It is practical and meaningful to explore a new kind of porous material with applicable strength and sorption performance by using EG as the base material.In this work, low-density EG based carbon-carbon composite was prepared using thermal-setting phenolic resin strengthened expanded graphite through a four steps process of impregnation, consolidation, carbonization, activation. The compression behaviors and anti-abrasion were measured. The result revealed that the strength of the composite had been improved showing its potential of application as a realizable absorbent.The XRD analysis indicated that the composite was made of graphite and amorphous carbon. SEM observation showed that the phenolic resin pyrolytic carbon was coating on the graphite granules and intercalating between graphite layers, filling part of the interior pores and reducing the total pore volume of EG. Pore texture analysis revealed that the composite had high BET surface and micropore area. The micropores mainly distributed in the pyrolytic carbon while the mesopores and macropores mainly in the graphite base. Some factors like activation source, activation time and temperature would influence the development of micropores rather than mesopores and macropores.The composite can efficiently adsorb oil substances, including pure oil, floating oil on water and emulsified oil in oil-water emulsion, with much higher efficiencies than AC can. The adsorption capacities for pure oils were between 10g/g and 20g/g. The specific capacity would increase with the... |
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