Page 269 - Gas Adsorption Equilibria

5. Oscillometry 255

Figure 5.7. Reduced masses resulting from oscillometric and gravimetric
adsorption measurements of He on activated carbon (Norit R1 Extra) at 293 K.
Gibbs excess masses adsorbed are calculated from

In Figure 5.8 also data of the Gibbs excess mass adsorbed
calculated from gravimetric measurements are depicted. These data
show a slight decrease with increasing sorptive gas density at high density
values indicating (again) problems in interpreting thermodynamically Gibbs
excess masses at high gas pressures, cp. Chapter 1. The absolute masses of
adsorbed have been calculated from data using
Eqs. (2.9, 2.10). They show a monotonous increase with increasing sorptive
gas density and coincide remarkably well thus proving – in this example –
that oscillometric and gravimetric measurements lead (within experimental
uncertainties) to identical results.

In Figure 5.8 also data of the Gibbs excess mass adsorbed
calculated from gravimetric measurements are depicted. These data
show a slight decrease with increasing sorptive gas density at high density
values indicating (again) problems in interpreting thermodynamically Gibbs
excess masses at high gas pressures, cp. Chapter 1. The absolute masses of
adsorbed have been calculated from data using