Enhanced Adsorption Selectivity of Aromatic Vapors in Carbon Capsule Film by Control of Surface Surfactants on Carbon Capsule

Carbon capsules with mesoporous wall and hollow interior were used to fabricate the sensing thin films for volatile aromatic vapors. To grow the thin film based on convenient layer-by-layer (LbL) process, carbon capsules need precoating with surfactants to assist their dispersion into aqueous solution. The influence of the surface covered surfactants on the adsorption selectivity of the corresponding carbon capsule film on aromatic vapors is studied. The results showed that poly (styrene sulfonate) (PSS) which is mainly covered on the outer surface of carbon capsules may be of benefit for higher accessibility of vapors with benzonoid nature to the carbon surfaces. A more enhanced adsorption selectivity to aromatic vapors is thus achieved compared to the cases of (sodium dodecyl sulfonate (SDS) and poly(allylamine hydrochloride) (PAH)), which can be fully or partial filled into the pores of carbon capsule.