Water permeability test
Water vapor permeability was estimated using the cup method
in accordance to ASTM E96 testing standard. Even though ASTM
E96 was developed for the measurement of water fluxes through
building materials; such as, fiberboard or gypsum, it can still be
employed to obtain data for relative comparison since the present
membrane fabrication technique allows the membrane’s water
permeance to be tuned. A membrane was mounted on the opening
of a test cup containing distilled water. The test cup is placed in a
chamber with controlled RH and temperature. A constant humidity
difference was applied between the two sides of the membrane for
water vapor permeation.Water vapor permeance, Kw, in mol m2 -