Critical Point of Fluid Confined in Nanopores: Experimental Detection and Measurement

For the first time, the presence of the critical point (CP) of fluids confined in nanopores is unambiguously demonstrated and measured using a differential scanning calorimeter with an isochoric cooling procedure. The behavior of the CP of CO2 and C2H6 in SBA-15 is found to deviate from theoretical predictions. The heat involved in capillary condensation is also discussed. The new and simple method of measurement introduced in this study opens the way to further investigate the criticality of fluids confined in nanopores.