Pristine and thermally-rearranged gas separation membranes from novel o-hydroxyl-functionalized spirobifluorene-based polyimides
KAUST DepartmentAdvanced Membranes and Porous Materials Research Center
Chemical Engineering Program
Physical Science and Engineering (PSE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/563261
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AbstractA novel o-hydroxyl-functionalized spirobifluorene-based diamine monomer, 2,2′-dihydroxyl-9,9′-spiro-bifluorene- 3,3′-diamine (HSBF), was successfully prepared by a universal synthetic method. Two o-hydroxyl-containing polyimides, denoted as 6FDA-HSBF and SPDA-HSBF, were synthesized and characterized. The BET surface areas of 6FDA-HSBF and SPDA-HSBF are 70 and 464 m2 g-1, respectively. To date, SPDA-HSBF exhibits the highest CO2 permeability (568 Barrer) among all hydroxyl-containing polyimides. The HSBF-based polyimides exhibited higher CO2/CH4 selectivity than their spirobifluorene (SBF) analogues (42 for 6FDA-HSBF vs. 27 for 6FDA-SBF) due to an increase in their diffusivity selectivity. Polybenzoxazole (PBO) membranes obtained from HSBF-based polyimide precursors by thermal rearrangement showed enhanced permeability but at the cost of significantly decreased selectivity.
SponsorsThe authors acknowledge KAUST funding for Professor Ingo Pinnau.
PublisherRoyal Society of Chemistry (RSC)