Hierarchical pore collapse

Another important consideration involves the hybridization of porous carbon with hierarchical 3D architectures, such as fibers or arrays. Wet chemical techniques are often useless as the mandatory solvent removal/drying typically results in the at least partial collapse of the nanocarbon pore structure. Gas phase deposition is a... 

Figure 5.11a shows mercury porosimetry data for a silica xerogel with mixed behavior the material first shrinks (full circles) up to a critical pressure Per beyond which its small, uncollapsed pores are intruded (open circles). The critical pressure is identified by a sudden change of slope of the volume variation curve. If the sample is depressurized before reaching Per (crosses), then indeed no mercury uptake is detected in the sample. The pore volume distribution in Fig. 5.11b can be computed using either Eqs. 5.4 or 5.5 depending on the considered pressure domain. At P=Pc both equations are valid so that the mechanical constant C - necessary for the hierarchical collapse equation - can be obtained conveniently (Pirard et ah, 1998) ... 

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