Evaluation of carbon nanopores using large molecular probes in grand canonical Monte Carlo simulations and experiments

Abstract Nanopores (pores between 1 and 5 nm) have been the object of a great deal of attention because they can selectively adsorb relatively large molecules such as macromolecules and polymer molecules. Conventional methods for analyzing porous structures—such as N 2 adsorption measurements at 77 K—can be used to investigate microporous and mesoporous structures, but there is a lack of investigation of nanopores or the boundary between micropores ( 6 . Grand canonical Monte Carlo simulations for N 2 and SF 6 suggested that SF 6 was adsorbed in 1.5–5 nm nanopores, while there was N 2 adsorption for the wide range of pore sizes. The SF 6 adsorption could therefore be used to confirm existence of the nanopores. To test this, we used single-walled carbon nanohorns as porous carbons with widely distributed pore size. SF 6 was well adsorbed only in the nanopores at 195 K, whereas N 2 adsorption was observed in all micropores and mesopores. This structural analysis of nanopores using a large-molecule probing method complements structural analyses using N 2 adsorption, as well as other techniques.