Hollow fibre membrane

A process for manufacturing a hollow fibre membrane having a supporting layer and a separating layer, said process comprising:

• (a) extruding a spinning composition comprising a first polymer and a solvent for the first polymer through an inner annular orifice of a hollow-fibre die;
• (b) co-extruding a composition comprising an organic nucleophilic reagent and a mixture of a solvent and a non-solvent for the first polymer, wherein the composition is either extruded through a central annular orifice of the hollow-fibre die or through an outer annular orifice of a hollow-fibre die;
• and
• (c) passing the hollow-fibre through a coagulation bath, wherein:
• (1) the first polymer is a hydrophobic polymer;
• and
• (2) the organic nucleophilic reagent is selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine and polvethyleneimines;
• and
• wherein the organic nucleophilic reagent crosslinks the first polymer.