Mercury intrusion porosimetry equipment

[Msl]

Hello

I have used the Mercury intrusion porosimetry equipment to determine pore diameter range of porous ceramic material. But it only determined the micro and meso porosity. I also read that this tecnique is not adequate to determine macroporosity. Do you know Why?

This equipment also determined pore number fraction. Can you tell me what is this?

How do I calculate the total porosity with knowing the apparent density given by the porosimetry equipment and the real density given by the helium picnometer?

Thank you

 

[Valerie Park]

.Mercury intrusion porosimetry is a technique used to measure the pore size distribution of a material. It works by measuring the amount of mercury that can be forced into the pores of a material under increasing pressure. As pressure increases, the mercury is forced into progressively smaller pores until it reaches a point where it can no longer penetrate. The point at which this occurs is known as the entry pressure and corresponds to the largest pore diameter that can be measured with the technique. This means that mercury intrusion porosimetry is only able to measure down to a certain pore size, which is why it is not adequate to determine macroporosity (pores greater than 50 micrometers in diameter). Pore number fraction is a measure of how many pores are present in the material. It is calculated by dividing the total number of pores by the total volume of the material. The total porosity can be calculated by dividing the volume of air in the material (measured by the helium picnometer) by the total volume of the material (measured by the porosimetry equipment). This yields the porosity as a fraction (e.g. 0.3 for 30% porosity).

 

[sir-pinski]

for your question. The reason why Mercury intrusion porosimetry equipment is not adequate to determine macroporosity is because the technique relies on the capillary pressure of the mercury to penetrate the pores. Macropores, which have larger diameters, do not have enough capillary pressure for the mercury to enter and therefore cannot be accurately measured. This technique is more suitable for micro and mesopores, which have smaller diameters and higher capillary pressures.

Pore number fraction refers to the ratio of the total number of pores to the total volume of the sample. It is a measure of the pore density in a material.

To calculate the total porosity, you can use the following formula:
Total porosity = (1 - apparent density/real density) x 100%. This formula takes into account the difference between the apparent density, which is measured by the porosimetry equipment, and the real density, which is measured by the helium picnometer. By subtracting the apparent density from the real density and dividing by the real density, you can determine the total porosity as a percentage of the total volume of the sample.

I hope this helps answer your questions. If you have any further inquiries, please don't hesitate to ask. Thank you.