Any composite material has to have a heterogeneous structure at a certain level of dimension (or range). The "ordinary" composites are heterogeneous in macro/micro level. While nanocomposites are heterogeneous in nano level (less than 100 nm). This means that reinforcement and the matrix are indistinguishable from each other in the micro/macro level, i.e. the structure, with respect to these phases, is homogeneous in the micro/macro level.

The term "nanocomposite" was formally adopted by Roy, Komarneni, and colleagues*. According to their definition nanocomposite is a composite of more than one Gibbsian solid phase where at least one of the phases shows dimensions in the nanometer range.

Based on that, mixing nanoparticles, if any in the solid form, may and may NOT produce nanocomposites. The homogeneity of the mixture in the microscale must be confirmed before designating it as nanocomposites>

* Roy, R .. Roy. R. A. and Roy. D. M .. Alternative perspectives on ·quasi-crystallinity': Non-uniformity and nanocomposites. Mater. Lett .. l 986, 4. 323-328.

Thank you very much sir. But I am new in this field, so, I am very much confused. But from the FETEM image, I think it can be designated as nanocomposite. I am providing you the image. It is indistinguishable and homogeneous from each other in the micro/macro level. Please kindly go through the image and suggest me, can I say it a nanocomposite?

It’s a mixture of fused sub- and post-micron aggregates and agglomerates. There are no single, discrete, independent particles < 100 nm. However, it probably meets the EU definition of nano. Have you measured the specific surface area?

Sir, I have measured the BET surface area of that material, which was 3 m2/g.

Somen Mondal Then your material is far from nano in terms of performance. You need an SSA > 60 m2/g for the material to be considered nano. As the SSA = 6/D(3,2), then your average particle size is 2000 nm or around 2 microns.

ok sir, thank you very much.

I think you can find the answer in this 1 year discussion https://www.researchgate.net/post/Can_we_define_a_nanocomposite_in_nanomaterials_as_a_mixture_of_two_or_more_components_that_does_not_have_chemical_or_physical_interactions

Thank you very much sir.

Sir, Alan F Rawle , I have repeated the BET test in another instrument, and it showed that the SSA is 595 m2/g. I was very much confused about the previous result as the SSA of only Activated carbon was 1360 m2/g. Hence, I have gone for repetition, and got that much (595 m2/g) SSA. Now what would be the case!!! It would be mixture or composite. Initially, I have indicated it as a mixture, and the paper is under review. Should it be changed or it is right???