Microscopy techniques (SEM, TEM and AFM) are efficient  tools  to investigate dispersion and homogeneity of  the nanocomposites

Microscopy techniques are efficient tools

Dear Dr. Alshamsi

Could you please introduce me paper(s) which has utilized TEM to investigate dispersion? 

Dear Ali

Please have a look at link below

Warm regards

https://www.researchgate.net/publication/278023986_Investigation_on_the_dispersion_of_carbon_nanotubes_in_solvent_media_effect_of_sonication_energy_and_carbon_nanotube_diameters

Conference Paper Investigation on the dispersion of carbon nanotubes in solve...

Dear Dr. Alshamsi

Thank you so much for your kind help

Using TEM/HETEM, surface morphology of graphene/reduced graphene oxide can be clearly seen including surface defect. But, the nanoparticles (NPs) dispersed on it can be well recognized and an excellent technique for the determination of dispersed NPs on the surface of graphene/reduced graphene oxide etc.  

You may also have a look on the following articles:

- Materials 2014, 7(7), 5212-5224

- Polymer composites Volume 35, Issue 12,  December 2014 , Pages 2318–2323

TEM will tell you about number of layers of your graphene, and size. If you deal with a dispersion on a surface, AFM is more suitable as you can do better statistics on a larger scale. 

 Dr Bouchiat, actually I deal with dispersion in a liquid phase in a solvent like water.

I understood that. But for TEM as for AFM analyses you cannot use the liquid phase directly. You have to spread your solution on a surface or membrane and dry it to look at the deposits. 

Dear Dr Bouchiat you are right, but in fact this is my originally question. Can we use TEM image (which has been obtained in a dried form) as an evidence to speak about the quality of dispersion (solution form)?

the answer is yes (you dry the solution on a lacey carbon grid and look at the density, size, thickness of materials but as I said  AFM is probably better suited for that analysis.

However, TEM is quite fine, but AFM would be much better for your purpose 

I am not sure that conventional TEM and AFM are suitable, because you need to dry the sample and it may be expected the sample in dry form to be different as compared to its liquid form.