Dear colleagues,

I added the total amount of 30% glycerol to 89% hydrolized PVOH and starch, and extruded them together to obtain the blend sheets (flat die). I want to observe the morphology on their cross-section.

I have searched in literature, and I have found several papers with SEM images of this blend, however it was impossible to observe any phase difference.

I had already tried BSE-SEM and EDS-SEM analysis after some iodine vapor exposition, but I had no results (maybe it could be my method, I had nothing to be based on, if you suggest anything about it, I would be grateful too).

Could you suggest any kind of extraction method to remove one of the phases (both materials are water soluble) or to stain one of them ?

Anyway, thanks