Size factor in calculations of the volume filling of narrow cylindrical pores in MSM-41

The estimates of the complete filling of narrow cylindrical pores in mesoporous materials of the MSM-41 type for adsorbates modeling argon atoms and nitrogen molecules calculated with and without the inclusion of the size factor have been compared. Calculations in the framework of the lattice gas model have been performed for pores with diameters from 2 to 10 nm. This size range is divided into three subranges: in the first size subrange where a fluid has a quasi-one-dimensional behavior (up to 4 nm), there is a qualitative difference between the isotherms; in the second subrange of pore sizes (up to 7 nm), the inclusion of the size factor leads to quantitative differences in the estimates of the total pore volume; for pores with diameters >7 nm, the size factor has no effect on the estimates of the volume filling of cylindrical pores.