Micropore characterization

To begin with, it should be noted that micropores fill at very low relative pressures, sometimes as low as 10 ^–7 w/w ⁰ , which corresponds to a nitrogen equilibrium pressure of 10 ^–4 mbar. To be able to highlight microporosity, it is therefore necessary to ensure that the apparatus used enables reliable measurements to be made at these low pressures. This requires not only a 0 to 1 mbar pressure gauge, but also a device that is sufficiently tight to obtain a static vacuum for the duration of the measurements. Moreover, the smaller the micropores, the longer it takes to reach equilibrium, since diffusion of nitrogen is...