Nanoscale Curvature Effect on Ordering of N2Molecules Adsorbed on Single Wall Carbon Nanotube

The experimental adsorption isotherm of N2molecules on mutually isolated single wall carbon nanotubes at 77 K agreed well with the grand canonical Monte Carlo simulated one. The N2adsorption isotherm had two steps stemming from monolayer formation on the internal surface and filling of the residual space of the internal tube pore. Although all of radial distribution functions of molecules adsorbed on the internal, external, and flat surfaces indicated a hexagonal packing structure, the radial distribution functions were different from each other. In particular, the radial distribution function of the monolayer on the internal surface showed an additional peak because of the markedly curved surface.