Hi, we are testing neat PVA membranes in pervaporation for ethanol dehydration. What we are observing is that it's not pervaporation happening there, in fact, it's simple permeation as the permeate is coming drop-wise in permeate flask. What could be the reasons for it, What should be the parameters to perform the pervaporation instead of permeation using neat PVA membranes? Thanks for your kind support in advance. Regards, Babar