Radical polymerization of polydivinylbenzene in the pores of activated carbon and structural characterization

Abstract

Polydivinylbenzene (PDVB) was hybridized in the nanosized pores of activated carbon (AC) via radical polymerization. The amount of PDVB was varied by changing the adsorbed amount of divinylbenzene (DVB). DVB was adsorbed in the AC pores with sizes of <4 nm without using any organic solvents. The DVB-adsorbed AC was mixed with a radical initiator, 2,2′-azobisisobutyronitrile (AIBN), and the mixture was heated for polymerization. Unpolymerized DVB and AIBN-derived impurities were removed from the resulting AC/PDVB hybrids through vacuum heating. The absence of PDVB on the outer surface of the AC particles was verified through scanning and transmission electron microscopies. Nitrogen adsorption/desorption measurements of the hybrids revealed that their specific surface areas as well as micro- and mesopore volumes linearly decreased with increasing amount of hybridized PDVB. The electric double-layer capacitor performance of AC/PDVB hybrids was evaluated through electrochemical measurements in an aqueous H₂SO₄ as the electrolyte. The results revealed that their capacitances and rate capabilities decreased with increasing amount of hybridized PDVB. Further, they suggested that the hybridized PDVB exists as agglomerates distributed uniformly in the micropores and mesopores irrespective of the amount of PDVB.