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particle size measurement
Posted Jul 31, 2015, 9:35 a.m. EDT 3 Replies
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i asked someone to measure particle size for my calcium carbonate powder. he did and what he gave me as result was 1351.32cm2/g. this wasn't what i was expecting. i expected result in mesh, inches, microns or millimeters. could someone help me make sense of this result? i want someone to help me relate cm2/g to the units above as i can not get a table to do the conversion for me. i want the result in any of the above units.
thank you.
thank you.
3 Replies Last Post Aug 2, 2015, 10:44 p.m. EDT
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Posted:
9 years ago
This person calculated the specific surface area of your calcium carbonate, which is in units cm2/g. Ask the person if they used BET (Brunauer, Emmett and Teller) nitrogen absorption to determine the specific surface area. If this is the only data you have available...it is possible to derive the particle size by assuming that the particles are spherical and also assuming you know the density of the powder.
However, this is not the typical method of measuring particle diameter (in micrometers). It is more typical to use DLS (Dynamic Light Scattering) or microscopy with a high-resolution microscope. You should be able to find instruction on how to use DLS online- you need to make a very dilute solution <0.05% in a liquid (that does Not dissolve CaCO3!) and sonicate >15 minutes to ensure there are no particle aggregates. There also may be a problem with particle settling, so ideally you would want the liquid to have a high density to keep the particles suspended.
Otherwise, just try putting a dilute solution of the particles on a microscope slide and performing image analysis. You can download ImageJ software for free, which you can use to measure the sizes of particles if you are able to view them with a microscope (they may be too small depending on your microscope resolution). This would give you an overall particle-size distribution, and you can find the mean particle size.
However, this is not the typical method of measuring particle diameter (in micrometers). It is more typical to use DLS (Dynamic Light Scattering) or microscopy with a high-resolution microscope. You should be able to find instruction on how to use DLS online- you need to make a very dilute solution <0.05% in a liquid (that does Not dissolve CaCO3!) and sonicate >15 minutes to ensure there are no particle aggregates. There also may be a problem with particle settling, so ideally you would want the liquid to have a high density to keep the particles suspended.
Otherwise, just try putting a dilute solution of the particles on a microscope slide and performing image analysis. You can download ImageJ software for free, which you can use to measure the sizes of particles if you are able to view them with a microscope (they may be too small depending on your microscope resolution). This would give you an overall particle-size distribution, and you can find the mean particle size.
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Posted:
9 years ago
Thank you very much Emily. If I assume that the particles are spherical but do not know the density as that was not measured and the person who gave me the result quoted above is very uncooperative, is there anyway to derive the density from what I have and thereafter derive the particle size from there. If yes, how do I go shout this? What are the formulas am supposed to use. Or would you be able to help me with the derivatives and find the parties size? Thank you very much once again .
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Posted:
9 years ago
Le Chatlier Flasks or pycnometers are a simple method for density of solid powders.
Also, I think the person just misunderstood what you were asking for...if you wanted the pore size...then BET method would have been correct. But you were actually interested in a particle size distribution?
This is a ebook that I used in a undergraduate particle technology class...hopefully you can access the link
www.particles.org.uk/particle_technology_book/particle_book.htm
Also, I think the person just misunderstood what you were asking for...if you wanted the pore size...then BET method would have been correct. But you were actually interested in a particle size distribution?
This is a ebook that I used in a undergraduate particle technology class...hopefully you can access the link
www.particles.org.uk/particle_technology_book/particle_book.htm