Yes.

ImageJ is used widely for the purpose for such application. when carrying out quantitative analysis from images, the most disputable part tends to be the method used for thresholding/segmentation/binarisation. After that its just pixel counting. we routinely perform morphometry (in 3D) using imageJ and other image processing apps.

however, you have to be careful about how you measure certain properties. for example, the area of a pore on a 2D image is an easy and robust metric since its just a matter of counting the pixels (or voxels) of your feature (scaling to your spatial resolution). on the other hand measuring the longest/shortest diameter is not as straightforward as certain methods (non iterative bounding box/feret) are not invariant i.e  rotating the image gives a different number!!

hope that helps a little.

sharif 

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SEM and imageJ can be used for the determination of pore size and their area fractions and conversion to volume fractions. Important: BET technique can provide information upto few nm size range pores or using the tomography. You can also use FiB to get the information on pore size using a large number of images from the surface to a reasonable depth.

So, there are many available techniques, but one need to always conduct a  complementary technique to compare the value.  

SEM is one of the methods for investigating porous structure. The suitability of the method depends on pore size. See: Inagaki M, Tascon JMD. Pore formation and control in carbon materials. In: Bandosz TJ, editor. Activated Carbon Surfaces in Environmental Remediation, vol. 7, Amsterdam: Elsevier; 2006, p. 49–105.

I think Alexander is right, and some reviewers could be critical on the quantitative data on porosity from SEM...

BET  technique encompasses external area and pore area evaluations to determine the total specific surface area in m2/g yielding important information in studying the effects of surface porosity and particle size in many applications.

I agree with Farzaneh, the Adsorption technique is better than SEM also you could contrast with the SEM image analysis. When you do the adsorption analysis you could obtain more information about distribution, size, volume and shape of pore

Yes.

We can also use the PSD (particles seize distribution) by diffusion laser for determine the specific area but it's difficult for these technics (SEM and PSD) to accede to the pores distribution versus BET which is more used 

Completely agrred with Megat Harun Al Rashid Megat Ahmad. SEM can only provide the surface porosity more accurately the structure of a surface porous or not. Some times researchers used to study the porous structure of polymeric membranes those are generally macrroporous in nature. It is better to go for BET analysis. It can give you many flavors regarding porosity of your sample i.e. surface area, total pore volume, pore distribution and many more. More over the orderness of your sample's porosity can be under stood from small angle XRD in the two theta range 0.2 to 7 degree.  If small angle XRD provide you a sharp peak then you can go for TEM analysis for better understanding of your sample's pore orderness.

Yes

SEM is usually NOT a suitable choice for pore size distribution(PSD) analysis, especially for those materials with a wide PSD, or for the case that pores are contributed by stacking of nanoparticles. A simple reason for this is that it would be quite tricky to judge where the pores are, especially for the stacking case.

A better and almost always suggested method to provide PSD is by N2 (or Ar, CO2, etc.) adsorption experiments, which is also widely accepted.

Only for those with a narrow and uniform PSD materials, such as MCM-41, TEM is a better choice. (Not SEM even in this case.)

SEM is not suitable technique for determination of a pore size distribution (PSD). Generally, a diameter of pores varies from about 0.6 nm (zeolites) up to a few hundreds of nm – very large macropores (in accordance with the IUPAC definition macropores have diameters higher than 50 nm). Using SEM, even of of a high quality you can observe only very large macropores. For a precise determination of PSD use adsorption-desorption technique (N2, Kr) combined with mercury porosimetry. Of course SEM may be useful for evaluation of size of particles and/or a texture of external surface.

SEM could approximately show a pore size distribution (PSD).

SEM can be an effective technique for determination of particle size analysis but isnot suitable for pore size distribution. BET or BJH are suitable.

Is your sample powder type or solid material

Dear Arun,

I have the same question and my sample is powder (ZnO  nanoparticles) and another one (TiO2 nanoparticles)

Dear Fazimah,

ISO 7198:2016, for example, describes a method called planimetric porosity (section A5.1.1.1) which consists on measuring the total area of voids and material within sample section observed on scanning electron microscopy images or micrographs.

The percentage of porosity is then retrieved by dividing the area of voids by the cumulative area of voids and material, and further multiplying by 100.

SEM is not suitable for pore size distribution. My suggestion to measure the surface area and the pore size distribution using

Nitrogen Gas adsorption technique BET and BJH.

The pore size obtained from SEM analysis is higher than that of BET analysis due to a particular small area was selected for the SEM analysis. Otherwise, the BET surface analysis technique based on N2 adsorption-desorption isotherm analysis provides complete details on the specific surface area and porosity of the overall samples. Usually, SEM analysis is not a suitable choice for the pore size distribution analysis. For the precise determination of the porosity of the sample, BET analysis was carried out in this manuscript. Thus the pore size distribution obtained from the BET analysis is acceptable.

perfect pore size distribution can not be get by SEM images, SEM is not suitable for pore size distribution, for the perfect nature multichannel BET surface analysis can be preferred.

I agree with the statement that SEM cannot substitute adsorption-desorption measurements and treatment of data by isotherm models – the BET isotherm used most frequently, other methods, e.g. for evaluation of micropores are possible to find in the relevant literature. However, it is necessary to stress that a good SEM picture (resolution about 100 nm) can significantly contribute to the description of external texture of sample. SEM allows characterization of particle shape, roughness (contribution to macropores) and estimation of particle size distribution (PSD). When properly done calculation of PSD from SEM, it is more reliable than for example laser methods. In the context with measurements of adsorption-desorption isotherms using small particles (micro_meter, or even lower, e.g. zeolites, activated carbon materials, etc.), condensation in an interparticle void volume in packed beds is important. This volume significantly contributes to a figure obtained for overall volume of macropores, e.g. using the BJH method. Therefore, good SEM pictures are necessary complements for characterization of powder porous materials (the relevant ISO standards can be applied).

Milan