A process for manufacturing a hollow fibre membrane having a supporting layer and a separating layer with a double orifice spinneret having an outer annular orifice and a central annular orifice, said process comprising,: (a) extruding a spinning composition comprising a first polymer and a solvent for the first polymer through the outer annular orifice of the double orifice spinneret; (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 extruded through the central annular orifice of the double orifice spinneret; and (c) passing the hollow-fibre through a coagulation bath, wherein: the separating layer is chemically adjoined to the supporting layer, the first polymer is a thermoplastic hydrophobic polymer chosen from a functionalized polyethersulfone, a polyamidoimide, a polyimide or a polyether imide; and the organic nucleophilic reagent comprises amino groups, has a molecular weight of 60 to 750.000 g/mol and is selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, or the organic nucleophilic reagent comprising amino groups is a polyethyleneimine, wherein the polyethyleneimine is linear or branched and has the general formula: wherein p + q is 8 to 5800 and p = 8 - 2900 and q = 0 - 2900. and a central annular orifice, said process comprising,: (a) extruding a spinning composition comprising a first polymer and a solvent for the first polymer through the outer annular orifice of the double orifice spinneret; (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 extruded through the central annular orifice of the double orifice spinneret; and (c) passing the hollow-fibre through a coagulation bath, wherein: the separating layer is chemically adjoined to the supporting layer, the first polymer is a thermoplastic hydrophobic polymer chosen from a functionalized polyethersulfone, a polyamidoimide, a polyimide or a polyether imide; and the organic nucleophilic reagent comprises amino groups, has a molecular weight of 60 to 750.000 g/mol and is selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, or the organic nucleophilic reagent comprising amino groups is a polyethyleneimine, wherein the polyethyleneimine is linear or branched and has the general formula: wherein p + q is 8 to 5800 and p = 8 - 2900 and q = 0 - 2900. (a) extruding a spinning composition comprising a first polymer and a solvent for the first polymer through the outer annular orifice of the double orifice spinneret; (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 extruded through the central annular orifice of the double orifice spinneret; and the composition is extruded through the central annular orifice of the double orifice spinneret; and (c) passing the hollow-fibre through a coagulation bath, wherein: the separating layer is chemically adjoined to the supporting layer, the first polymer is a thermoplastic hydrophobic polymer chosen from a functionalized polyethersulfone, a polyamidoimide, a polyimide or a polyether imide; and the organic nucleophilic reagent comprises amino groups, has a molecular weight of 60 to 750.000 g/mol and is selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, or the organic nucleophilic reagent comprising amino groups is a polyethyleneimine, wherein the polyethyleneimine is linear or branched and has the general formula: wherein p + q is 8 to 5800 and p = 8 - 2900 and q = 0 - 2900. the separating layer is chemically adjoined to the supporting layer, the first polymer is a thermoplastic hydrophobic polymer chosen from a functionalized polyethersulfone, a polyamidoimide, a polyimide or a polyether imide; and the organic nucleophilic reagent comprises amino groups, has a molecular weight of 60 to 750.000 g/mol and is selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine, or the organic nucleophilic reagent comprising amino groups is a polyethyleneimine, wherein the polyethyleneimine is linear or branched and has the general formula: wherein p + q is 8 to 5800 and p = 8 - 2900 and q = 0 - 2900.