Hy everyone, i would like to know when the porous volume of a zeolite diminshes does this mean that we lose some of its cristallinity? thanks for answering to my question please.
thanks in advance.
If you treat a ~100% crystalline sample of a given type of silicoaluminate zeolite with some reagent that remove Al or Si you will lose crystallinity and increase some kind of pores and pore volume.
Thank you Mr Joao G R.Poco for answering my request but my treatments were heat treatments (ion exchange, impregnation) .
After ion exchange of H-form of zeolites, or after impregnation, you input cations or molecules inside to micropores, so consequently the volume of micropores logically decreases at the same, unchanged crystallinity. The degree of crystallinity after ion-exchange or impregnation you can verify by XRD, but at the same time you must to take into account that the content of crystalline phase (zeolite) is lower by the introduction of mass of cations or impregnating molecules.
If you are dealing with FAU zeolites ymou should see ASTMs standards to determine crystallinty in zeolites. Some of the peaks change their height after ion exchange but there is others that does not change.
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