High surface area hyper-cross-linked resins containing multi-walled carbon nanotubes

A synthetic route to produce high surface area polystyrene networks consists in the post cross-linking of linear polystyrene chains or lightly cross-linked "gel-type" resins based on styrene (St), divinylbenzene (DVB) and vinylbenzyl chloride (VBC). The precursor resin is prepared by suspension polymerization, then through post cross-linking various structural bridges between neighboring phenyl groups are obtained. In the present study, a new synthetic process was set up, based on the mass polymerization of the gel-type resin. Therefore, high specific surface area polymers were prepared through extensive cross-linking of a series of precursor resins obtained by mass polymerization and based on St, DVB and VBC monomers. The proposed synthetic protocol allowed easily incorporating multi-walled carbon nanotubes (MWCNTs) into the precursor, leading to a new class of nanocomposites based on gel-type resins and containing different amounts of MWCNTs. Prior to the synthesis of the nanocomposites, MWCNTs were properly functionalized to improve their dispersion in the host matrix. By the post cross-linking of these precursors new high surface area nanocomposite resins were obtained. The distribution of the filler was evaluated by TEM analysis. Furthermore, the extent of the hyper-cross-linking reaction and the structure of the resin were studied by means of FTIR and NMR spectroscopy. The effects of the precursor composition and the nanotubes content on the surface area of the resin, its pore size distribution and gas sorption capacity were evaluated through nitrogen and hydrogen adsorption analysis.