The CO2 desorption in MOFs is performed by heating or applying low pressure(vacuum). It is observed that by incorporating MOFs in polymeric membranes, the CO2 selectivity increases in general. My question is that how desorption of CO2 occurs in continues permeation process? each time when MOF-based membrane is used at displays higher CO2 selectivity. so, why the MOfs saturated with CO2 do not show reduced selectivity in MOF-based membranes in continues permeation process?