Abdorrazzagh Mohebbi

I believe you might even use this method for qualitative purposes but I'm not sure. If you decide to use it, note that you should change in the equation the values of the water vapor pressure gradient in the air (3085.05 Pa) to the ethanol vapor pressure gradient.

In addition, this methodology varies according to the polymer film that will be using in the Payne cup. So they are variable variables.

Best Regards

Breidi Albach

Hi Abdorrazzagh,

As you pointed out, the cup method (ASTM E96) should be applicable to other vapors as long as you use the correct the partial and saturation pressures.

You can modify the setup to fit your sample requirements. Check out this paper on silk where they used pretty small films:

http://www.nature.com/articles/srep25263

You can use other gas permeability methods for ethanol vapors (coulometric test or pressure rise methods), but that requires a much fancier setup.

Hope it helps!

Apf