Metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes with enhanced selectivity

A method for producing a metallopolyimide precursor fibers for aging-resistant carbon molecular sieve hollow fiber membranes having enhanced selectivity, comprising the steps of:

• ejecting a bore fluid from a circular opening in a hollow fiber spinneret, cations of a transition metal being dissolved in the bore fluid;
• extruding a core spin dope composition from an annular opening that surrounds the circular opening, the core spin dope composition comprising a polyimide dissolved in a solvent;
• allowing the extruded core spin dope composition to traverse an air or inert gas gap to produce a nascent hollow fiber;
• allowing the nascent hollow fiber to travel through a coagulation bath of a non-solvent where still-dissolved portions of the polyimide in the nascent hollow fiber are solidified via phase inversion, wherein the transition metal cations diffuse into the hollow and complex with electronegative regions of the polyimide;
• and
• drying the solidified hollow fiber.