I have some highly porous materials and I have to determine the density of them.
Depending on your sample, you can measure the density by hydrostatic weighing. You can find a brief description on wikipedia http://en.wikipedia.org/wiki/Hydrostatic_weighing
One thing to watch out for is that you will need to measure the temperature at which you weigh the sample, as you will need to know the density of water at that temperature.
As you know, density is the ratio of mass to the volume of the sample. Find out the porosity of the sample using any of the standard methods and deduct it from the volume of the sample to get the actual volume. Weigh your sample to get the actual weight and you can calculate the density.
Depending on the nature of your sample (hydrophobic or hydrophilic), use an absorbing solvent. From the weights of wet and dry samples you can also determine the porosity.
Do you what to know the nominal density, or the density of the solid from which the structure is constructed (i.e.the material if it did not contain any pours)?
Skeletal density of porous materials can be measured by helium pycnometry.
For light weight and very porous materials, temperature and specific gravity of the liquid used are important considerations for using Archimede's principle for such a measurement.
Agree strongly with Tomin Liu, however, the water has perfectly wett your sample surface, but currently most reliable method was proposed by Soumen Dasgupta...
You can find out apparent density simply by ratio of mass and apparent volume, provided you have a sample of known geometric shape (like cube, cuboid etc). For true density, you can crush the sample(if possible) into a fine powder and press fill in a cylinder of known volume. Record the weight and volume. The simple method is to used helium gas pycnometer.
You must clearly define the composition of your material and know what kind of pores are, if they are micropores, you must not only measure the density by the Archimede's principle, but also the microporosity with nitrogen physisorption.
The "density" should be defined, as true (skeletal) density is not bulk (apparent) density. True density should be measured by helium pycnometry at temperatures preferably above room temperature (for avoiding He adsorption in microporous solids, not negligible !), after thorough grinding of the material for avoiding the possible contribution of closed porosity. Mercury porosimetry may work (at pressures of 4000 bar, at least), but leads to less accurate results. Or even to wrong results if microposity is present. For bulk density, just weight a sample of even shape and known dimensions. Or, if you can't and if the pores are not too big, try powder pycnometry, very efficient for aerogels of irregular shapes for example.
Alain
Density is defined as the ratio of mass to the volume of any sample of matter . You should Find out the porosity of the sample using any of the standard methods and desubtract it from the volume of the sample to get the actual volume. Weigh your sample to get the actual weight and then you can calculate the density. Depending on the nature of the sample is it hydrophobic or hydrophilic, you should use an absorbing solvent. From the weights of wet and dry samples you can also determine the porosity.
Try to calculate volume fraction of your porous sample. Volume fraction empirically, can be given as following: Volume fraction =density of sample/density of pure sample, then you can estimate the density of your sample: But you need to define the composition and the purity
I don't know how porous and what state of your material is. If your sample is something like rock, here I can recommend a method for both grain density and bulk density measurement. The porosity of sample is also can be calculated using this method. Li S. J. et al. 2012. A new method for the measurement of meteorite bulk volume via ideal gas pycnometry. Journal of Geophysical Research Planets. 10/2012; 117(E10):10001-. DOI: 10.1029/2012JE004202
Article A new method for the measurement of meteorite bulk volume vi...
what is the theoretically method to predict the density distribution in porous part?
If i have light weight material like Rice husk ash or coal bottom ash, how can i measure its density?
Find the answer uploaded as a PNG image. One must calculate the porosity and proportion of the pore space occupied by the phase.
you can use the nitrogen sorption to determine the porosity, then calculate the density of the porous materials concerning the density of bulk counterparts
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