| abstract |
Gaseous molecules, such as H<sub>2</sub>, CO<sub>2</sub>and CH<sub>4</sub>, can be separated using a hybrid organic-inorganic polyimide network membrane, wherein the polyimide contains bis-imide units of formula 1wherein A represents an organic moiety having 2-22 carbon atoms; or corresponding tris-imide groups,wherein a nitrogen atom of two or more of said bis-imide units is linked to a group Q of a polyhedral oligomeric silsesquioxane (POSS) group of formula 3 Q<sub>m</sub>R<sub>(2n-m)</sub>Si<sub>2n</sub>O<sub>3n</sub>.xH<sub>2</sub>O 3whereinQ is C<sub>p</sub>H<sub>q</sub>bound to a silicon atom,R is hydrogen, hydroxy or C<sub>1</sub>-C<sub>4</sub>alkyl, alkoxy, hydroxyalkyl, aminoalkyl or ammonioalkyl, bound to a silicon atom,m is from 2 up to 2n,n is from 2 up to 6,p = 1 to 6;q = 2(p - r) with r = 0, 1, 2 < p; andx is from 0 to 2n-1. |