Patent ID: 8404278

Claim:
A method of manufacturing porous polyimide microparticles having pore diameters of more than 10 nm for forming carrier matrices for adsorbers, the method comprising the following steps: a) providing a polymer solution of at least one polyimide polymer and a solvent or a solvent mixture, b) converting the polymer solution to microparticles by spraying or thermal phase inversion, c) treating the microparticles obtained in step b) with an aqueous functionalization solution including 1 to 10 wt % of an amine-containing modifier chosen from the group of diamines and triamines, wherein the amine-containing modifier comprises at least one of a primary, a secondary and a tertiary amine group and further comprises alkylene groups with 2 to 5 C atoms interconnecting the amine groups, wherein the treatment is performed at a temperature of 50 to 100° C. for a period of 5 min to 4 hours, and d) washing the obtained modified microparticles to remove therefrom the amine-containing modifier.