The adsorption of organic vapours on carbon aerogels and their precursor organic aerogels

Carbon aerogels were prepared by sol-gel polycondensation of resorcinol and furfural in alcohol using hexamethylenetetramine as a catalyst, and then directly drying the organic gels under conventional ambient pressure drying conditions, followed by carbonization under a nitrogen atmosphere. The structures of the organic aerogels and the carbon aerogels obtained were investigated by TEM and N2 adsorption-desorption analysis. Relationships between the structure and adsorption property of the carbon aerogels and their precursor organic aerogels were studied by the adsorption of organic vapor. It was found that both the organic aerogels and the carbon aerogels have a higher static adsorption capacity for polar organic vapors than that for non-polar organic vapors. With an increase of pyrolysis temperature, the aerogels have a higher adsorption capacity for the non-polar benzene vapor with various concentrations and for the polar ethanol vapor with a low concentration, but have a lower adsorption capacity for the polar ethanol vapor with a high concentration. With an increase in the concentration of the organic vapors, the adsorption capacity of the aerogels for the non-polar benzene vapor only slightly increases whereas that for the polar ethanol vapor sharply increases. In addition, the desorption efficiencies of the various organic vapors on the organic aerogels and on their related carbon aerogels at room temperature are up to 60 - 85 %, and that on the former is higher than that on the latter.