I did not get any micropore from t plot. So I am confused wheather my sample does not have micropore or it is having but not showing as my data has not been taken so low relative pressure. We are starting measurement from p/p0 = 10-2. Between my two samples there is difference between isotherm plateau (from where the isotherm is getting started). What does it indicate?
Please reply.
Hi Debarati, The model in is agreement with your data --> i.e. no microporosity at all. Your curves look like a type III isotherm, typical of weak adsorption energies. I don't see soo much difference between the two curves except in term of proportions, SBET(N2,7)>SBET(N2,2), but the shapes seem similar.
If you had micropores, they would be filled at low P, inducing a high slope (dV/dp>>1, type I,II or IV). it is not the case in your exp.
Micropores usually strongly adsorb (a lot) at pressures of less than P/P0 < 0.1. Your sample in black curve has no accessible micropores, and your sample in red curve has very little.
Mesopores should also be very little (small hysteresis and low adsorption at less than P/P0 < 0.7.
Just by inspection, I would say that your sample have large mesopores/macropores. So your t-plot is correct.
By seeing your BET curves, I think that your sample in black curve has no micro/mesopores with the very low cumulative pore volume. On the other hand, the red curve sample has shown macropores (If this sample shows mesopores then pore size would be between 40 nm to 50 nm) with cumulative pore volume greater than black curve sample.
I hope it will help you.
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