I am attempting to make a covalent organic framework membrane for gas separation. Some articles use GPU as unit, others use Barrer. Which one should I choose as unit?
depend on your membrane, if using Barrer you need to consider thickness of membrane in your calculation, while GPU the thickness of membrane is not considered.
Barrer is a non SI unit of gas permeability used in the membrane technology, while GPU is used in the measurement of gas permeance. Permeance can be expressed as the ratio of the permeability with the thickness of membrane.