Surface functionalization and pore size manipulation for carbons of ordered structure

Covalent functionalization and pore size manipulation were successfully achieved on ordered mesoporous carbons, by using a method in which diazonium compounds were in-situ generated and reacted with the carbon surface. Aryl groups substituted on the 4-poisiton (Ar-R, R = chlorine, ester, and alkyl) were covalently attached to the surface of hexagonally structured carbon, which was synthesized using ordered silica SBA-15 as template. The presence of these functional groups on the modified carbons was confirmed with Fourier transform infrared spectroscopy, thermogravimetric analysis, electron microscopy, and nitrogen adsorption. A relatively high grafting density of similar to 1.5 mu mol/ml was achieved. Chemical modification considerably changed the pore width from 3.0 nm for the unmodified samples to similar to 1.4 nm for modified samples, while the primary hexagonal structure and the unit parameter of ordered mesoporous carbon were retained after attachment of surface functionalities.