Surfaces, POSS-based molecules

The monolayer capacity Vm is of primary interest because it allows for the calculation of the surface area based on the area occupied by each adsorbed gas molecule. According to Equation (9.27), a plot of p/[V(po - p)] versus p/po should be linear over the pressure region noted above. From the slope of the line, S = (c - l)IVraC and the intercept I = 1/VatC one can calculate the monolayer capacity Vra of the solid and thereby its specific surface area Agi... 

Most commercial instruments using gas adsorption for surface area and porosity determination are based on the BET isotherm. In Eq. (1.45), the monolayer capacity Vm can be used to calculate the surface area on the basis of the area occupied by each adsorbed gas molecule. According to Eq. (1.45), a plot of p/[Va(p0 - p)] versus p/po is linear. From the slope and the intercept, Vm can be obtained. Thus, the specific surface area S can be obtained as... 

The method of Neimark [7, 8, 33, 34] for the determination of the surface fractal dimension of a microporous solid is based on the adsorption isotherm equation that was developed by Kiselev [35]. This equation relates the surface area of pores filled by the adsorbate S(x) to the amount of adsorbed molecules N(x) at a given relative pressure x = pf po. ... 

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