Open pore volume

Symbol Solid material volume Open pore volume Closed pore volume Interparticle void volume... 

By determining the apparent density of coal in fluids of different but known dimensions, it is possible to calculate the pore size (pore volume) distribution. The open pore volume (V), the pore volume accessible to a particular fluid, can be calculated from the relationship... 

In the petroleum industry, the effective particle density of free-flowing cracking catalysts is measured indirectly by measuring the open pore volume. This consists of adding water or another liquid of low viscosity and volatility, to the powder until the liquid has filled all the open pores and it starts coating the external surfaces of particles the powder cakes-up by surface tension at this point and stops flowing. 

Porosimetry The determination of the open pore volume in a material. Example Mercury porosimetry, where mercury is hydrostatically forced into the pores and the weight change is measured. Porosimetry can be used in the specification of sputtering targets formed by powder pressing processes. 

Porosity, open Pore volume that is interconnected and coimected to the surface. May or may not affect measured density depending on the measuring technique. 

The filler process typically results in open porous glass or glassceramic parts with an open pore volume of around 60vol % and only 8vol % of deadend pores and 2 vol % of closed pores. 

Textural properties were obtained from measurement of true (helium) and apparent (mercury) densities, total open pore volumes and pore volume distributions. For determination of the helium densities, a Micromeritics Autopycnometer 1320 was used. Apparent densities were determined in a Carlo Erba Macropore Unit 120. The pore volume distributions were evaluated with a mercury porosimeter. Carlo Erba 2000. Specific surface areas were determined by physical adsorption in a Omnisorb 360 and a Sorptomatic Carlo Erba 1900. Nj at 77 K and CO2 at 273 K were used. We assumed a cross-section for a molecule of N2 of 0.162 nm and of 0.187 nm for a molecule of COj. All textural properties are e.xpressed on a dry ash free basis (daf). 

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