Process for fabricating PBI hollow fiber asymmetric membranes for gas separation and liquid separation

摘要

The invention provides methods for preparing an asymmetric hollow fiber, the asymmetric hollow fibers prepared by such methods, and uses of the asymmetric hollow fibers. One method involves passing a polymeric solution through an outer annular orifice of a tube-in-orifice spinneret, passing a bore fluid though an inner tube of the spinneret, dropping the polymeric solution and bore fluid through an atmosphere over a dropping distance, and quenching the polymeric solution and bore fluid in a bath to form an asymmetric hollow fiber.

主权项

1. A method for preparing an asymmetric hollow fiber, the method comprising:
(a) passing, through an outer annular orifice of a tube-in-orifice spinneret, a polymeric solution comprising: (i) 15-25 wt % of a polybenzimidazole; (ii) 1-5 wt % of a polymeric poreforming material; and (iii) a solvent with respect to the polybenzimidazole; (b) passing, though an inner tube of the spinneret, a bore fluid comprising: (i) 65-99 wt. % of a non-solvent with respect to the polybenzimidazole; and (ii) 1-35 wt. % of a solvent with respect to the polybenzimidazole, wherein the bore fluid maintains the polymeric solution in an annular shape; (c) dropping the polymeric solution and bore fluid through a gap, wherein the gap comprises an atmosphere and a dropping distance of 0.3to 20 cm; (d) quenching the polymeric solution and bore fluid in a bath to form an asymmetric hollow fiber having an annular shape and comprising first and second concentric layers, wherein the first layer contacts the second layer and is non-porous, and wherein the second layer is porous having pores in the range 5-250 nm, and the chemical composition of the first layer and the chemical composition of the second layer are the same, wherein: the polybenzimidazole is sulfonated polybenzimidazole.