DETERMINATION OF THE PORE STRUCTURE OF POROUS MATERIALS USING ELECTRICAL CONDUCTANCE

A new method for determining the pore structure of porous materials has been developed. The methodology combines the plastic ice model for solid-liquid phase transitions of pore water with relationships between conductance and temperature, and conductance and pore structure. With these relationships and measurements of the electrical conductance and the corresponding temperature of a saturated porous material subjected to a cycle of capillary freezing and melting, a pore size distribution is obtainable.

Baaed on this methodology a conductometric phase transition poroai-meter was constructed. The pore size distribution of porous Vycor glass was measured using this porosimeter. The modal neck and body radii measured by thia method are 28 and 55 angstroms respectively. These results are comparable to those obtained using other techniques. The modal neck and body radii measured on the same sample by mercury porosimetry are 30 and 85 angstroms and by phase transition porosimetry, 27 and 49 angstroms, respectively.