Thermally rearranged (TR) HAB-6FDA nanocomposite membranes for hydrogen separation

Enhanced gas separation and mechanical properties of fluorene-based thermal rearrangement copolymers

“…[19][20][21][22] It is reported that the bimodal microporous structure of TR polymers is in the range of 0.3-0.4Å and 0.7-0.9Å. [23][24][25][26] The unique hourglass structure allows the TR polymer to have both high gas permeabilities and selectivities simultaneously. [27][28][29][30] However, the trade-off relationship between gas permeabilities and selectivities still exists, so for some gas pairs, such as O 2 /N 2 and CO 2 /CH 4 , the separation performance of TR polymers needs to be further improved to meet the practical applications.…”

A Facile Synthesis of (PIM-Polyimide)-(6FDA-Durene-Polyimide) Copolymer as Novel Polymer Membranes for CO2 Separation

“…This order in permeabilities can be explained by the diffusivity, which takes the same order: CO 2 >> N 2 > CH 4 , as shown in Table 3 and Figure 6. Thus, the order of diffusivity is determined by the kinetic diameter of the penetrant gases, which is inversely proportional to the gas molecule size [CO 2 (3.30 Å) < N 2 (3.64 Å) < CH 4 (3.80 Å)]; that is, smaller gases diffuse through the polymer matrix faster than larger gases do [31,32].…”

Recent progress in the development of ionic liquid‐based mixed matrix membrane for CO 2 separation: A review

“…Since PIM's permeability decreases over time, attempts have been made to boost the membrane stability and CO 2 /CH 4 selectivity via a cross‐linking approach, but limited success was reported 59,60 . Besides PIM, thermally rearranged (TR) polymer is another new polymer material that have been applied in gas separation membrane 61,62 . The PI precursor containing ortho functionality is thermally converted or rearranged at high temperature (>350°C) during the synthesis of TR polymer containing microporous structure 38 .…”