Glassy polymer membranes fluorinated

In the mid-1990s, MTR Inc. evaluated at laboratory scale (on 1-2 m membrane modules) a wide array of composite membranes which selective membranes were made of various glassy or rubbery polymers (Table 6.5). Intuitively, rubbery polymers proved to be more selective toward methane (due to its higher sorption, induced by its more condensable behavior than nitrogen) while glassy polymers, especially fluorinated ones, proved to be more selective towards nitrogen (due to diffusive selectivity). 

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