I can not see what you calculated to be the specific surface of your PAni sample.

What I can comment now is that we found N2 (nitrogen) being not useful to be used on PAni, for unknown reasons. It seemed, N2 would not properly adsorb on PAni.

we found a very low specific surface which simply did not match what we saw in SEM and which particle size we achieved during dispersion (depending on how we proceeded: down to 10 nm)

Bernhard Wessling according to the IUPAC 2015 report, there are few types of isotherm to describe the porosity of a material...

those isotherm are convex or concave shape, but my one is almost linear;

i have 3 copolymer samples, one shows concave isotherm means it is mesoporous; but other 2 such linear is making me questionable...

dont understand, is it ok or i made any mistakes?

please check the following reference...

M. Thommes, K. Kaneko, A.V. Neimark, J.P. Olivier, F. Rodriguez-Reinoso, J. Rouquerol, K.S. Sing, Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report), Pure Appl. Chem. 87 (9-10) (2015) 160. https://doi.org/10.1515/pac-2014-1117.

yes, but apart from isotherms - what is the specific m² figure your measurement tells you? (independant of what s the porosity, first I want to know what does it tell you about specific surface in total)

63.85 of what? m²? cm²?

Average pore diameter: 6.63 of what? nm? km?

Bernhard Wessling

Cumulative pore volume (V/ml/g): 0.10

Average pore area(S/ m²/g): 63.85

Cumulative pore diameter /nm: 6.63

That's not bad, I am surprised; I assume this is not a pore area but the real outside surface area; that would correspond with the small pore volume value, isn't it?

Bernhard Wessling

yes sir...to my understanding this is the outside surface area...and have some pores in it...

regarding pores, I don't know how your polymer looks like - in my case, there had been no pores at all;

can you provide high-resolution SEM pictures?

Bernhard Wessling

please check the image file

thanks for sending, but for determining whether or not there are pores in your product (which I have never found in the mines), you would need to look at a much better / higher magnification and resolution;

what you see here is an agglomeration or flocculation of primary particles which all of them have a diameter of about 10 nm;

so your BET analysis describes the surface area available to N2 for these primary particles adsorbed onto their neighbours;

you can not tell whether within the 10 nm particles (which are the real primary units!) there are pores or not -

- which I doubt, I have never seen any and I concluded the primary particles are compact.

Please look at this publication as well:

Article New Insight into Organic Metal Polyaniline Morphology and Structure

and references cited therein (all or most of them available here in RG, if not, I can probably send you)