Relationship between intrinsic pore-wall corrugation and adsorption hysteresis of N_2, O_2, and Ar on regular mesopores

摘要

The effects of the pore width on the hysteresis of the adsorption isotherm of N_2, O_2, and Ar on mesoporous silica at 77 K were examined. A new analysis for the adsorption hysteresis was developed using the Saam-Cole theory. The critical thickness difference DELTAl_c(=l_c-l_e) for adsorbed film, which was derived from this anlaysis, was assoicated with the intrinsic mesopore width distribution due to the surface corrugation, giving the theoretical dependence of the adsorption hysteresis on the pore width and adsorbate; the critical pore width for N_2 is about 4 nm and those for O_2 and Ar are about 3 nm, agreeing with the experimental results.