摘要:
A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possess on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to ≦25 ml/(h·m2·mmHg). The hollow fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient of cytochrome c that satisfies the equation SCcc≧5·10−5·UFRAlb3−0.004·UFRAlb2+0.1081·UFRAlb−0.25.
摘要:
A hydrophilic, semipermeable hollow-fiber membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possesses on its inner surface a porous separating layer and an open-pored supporting layer adjoining the separating layer, and has an ultrafiltration rate in albumin solution of 25 to 60 ml/(h·m2·mmHg). The hollow-fiber membrane is free from pore-stabilizing additives, and has a minimum sieving coefficient for cytochrome c of 0.8 and maximum sieving coefficient for albumin of 0.005. Method for the preparation of such membranes based on coagulation induced by a non-solvent, whereby a spinning solution of a synthetic first polymer and possibly a hydrophilic second polymer is extruded into a hollow fiber through the annular slit of a hollow-fiber die with simultaneous extrusion of a coagulation medium as the interior filler through the central opening of the hollow-fiber die, the interior filler initiating coagulation in the interior of the hollow fiber as a result of which a separating layer on the inner surface of the hollow-fiber membrane is formed as well as the membrane structure, the method being characterized in that the interior filler contains a polyelectrolyte with negative fixed charges.
摘要:
A hydrophilic semipermeable hollow-fiber membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fiber membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fiber membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC≧5·10−5·UFRAlb3−0.004·UFRAlb2+1.081·UFRAlb−0.25.
摘要:
A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilising additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC≧5·10−5·UFRAlb3−0.004·UFRAlb2+1.081·UFRAlb−0.25 A method for producing such membranes by a coagulation process induced by a non-solvent, in which a spinning solution comprising a synthetic first polymer and possibly a hydrophilic second polymer is extruded through the annular slit of a hollow-fibre die to give a hollow fibre, and a coagulation medium that initiates coagulation in the interior of the hollow fibre is simultaneously extruded through the central opening of the hollow-fibre die, the coagulation medium initiating coagulation in the interior of the hollow fibre for formation of a separating layer on the inner surface of the hollow fibre and formation of the membrane structure, the method being characterised in that the interior filler contains a polyelectrolyte with negative fixed charges.
摘要:
A hydrophilic, semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a porous separating layer and an open-pored supporting layer adjoining the separating layer, and has an ultrafiltration rate in albumin solution of 25 to 60 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilising additives, and has a minimum sieving coefficient for cytochrome c of 0.8 and maximum sieving coefficient for albumin of 0.005. Method for the preparation of such membranes based on coagulation induced by a non-solvent, whereby a spinning solution of a synthetic first polymer and possibly a hydrophilic second polymer is extruded into a hollow fibre through the annular slit of a hollow-fibre die with simultaneous extrusion of a coagulation medium as the interior filler through the central opening of the hollow-fibre die, the interior filler initiating coagulation in the interior of the hollow fibre as a result of which a separating layer on the inner surface of the hollow-fibre membrane is formed as well as the membrane structure, the method being characterised in that the interior filler contains a polyelectrolyte with negative fixed charges.
摘要:
A hydrophilic semipermeable hollow-fibre membrane for blood treatment, with an integrally asymmetric structure based on a synthetic polymer. The hollow-fibre membrane possesses on its inner surface a separating layer and an adjoining open-pored supporting layer, and has an ultrafiltration rate in albumin solution of 5 to 25 ml/(h·m2·mmHg). The hollow-fibre membrane is free from pore-stabilizing additives and has a maximum sieving coefficient for albumin of 0.005 and a sieving coefficient for cytochrome c that satisfies the equation SCCC≧5·10−5·UFRAlb3−0.004·UFRAlb2+1.081·UFRAlb−0.25A method for producing such membranes by a coagulation process induced by a non-solvent, in which a spinning solution comprising a synthetic first polymer and possibly a hydrophilic second polymer is extruded through the annular slit of a hollow-fibre die to give a hollow fibre, and a coagulation medium that initiates coagulation in the interior of the hollow fibre is simultaneously extruded through the central opening of the hollow-fibre die, the coagulation medium initiating coagulation in the interior of the hollow fibre for formation of a separating layer on the inner surface of the hollow fibre and formation of the membrane structure, the method being characterized in that the interior filler contains a polyelectrolyte with negative fixed charges.
摘要:
Method for producing this membrane from a casting solution comprising the hydrophobic first sulfone polymer and the hydrophilic second polymer in a solvent system, the method comprising the steps of pouring the casting solution, conditioned to a molding temperature, onto a carrier to form a film, which carrier has a temperature that is higher in comparison to the molding temperature, conveying the film through a climate-controlled zone, initiating the coagulation in a coagulation bath for the formation of a membrane structure, withdrawing the membrane structure from the carrier with a speed that is increased in comparison to the carrier speed, stabilizing, extracting, and subsequently drying the membrane.
摘要:
Method for producing this membrane from a casting solution comprising the hydrophobic first sulfone polymer and the hydrophilic second polymer in a solvent system, the method comprising the steps of pouring the casting solution, conditioned to a molding temperature, onto a carrier to form a film, which carrier has a temperature that is higher in comparison to the molding temperature, conveying the film through a climate-controlled zone, initiating the coagulation in a coagulation bath for the formation of a membrane structure, withdrawing the membrane structure from the carrier with a speed that is increased in comparison to the carrier speed, stabilizing, extracting, and subsequently drying the membrane.
摘要:
Integrally asymmetric flat membrane for microfiltration comprising at least 40 wt. % of a hydrophobic first sulfone polymer and a hydrophilic second polymer with a pore size distribution over the membrane wall, having a separating layer in the wall's interior, and also having, in the direction from this separating layer, pore sizes increasing towards the surfaces, the second surface having pores with a mean diameter of at least 1 μm. The membrane comprises the hydrophilic second polymer in a concentration of 0.1-10 wt. %. The separating layer is located in an region facing the first surface, and the pore size passes through a maximum in the direction from the asymmetrical region towards the second surface.Method for producing this membrane from a casting solution comprising the hydrophobic first sulfone polymer and the hydrophilic second polymer in a solvent system, the method comprising the steps of pouring the casting solution, conditioned to a molding temperature, onto a carrier to form a film, which carrier has a temperature that is higher in comparison to the molding temperature, conveying the film through a climate-controlled zone, initiating the coagulation in a coagulation bath for the formation of a membrane structure, withdrawing the membrane structure from the carrier with a speed that is increased in comparison to the carrier speed, stabilizing, extracting, and subsequently drying the membrane.
摘要:
The invention relates to a method for producing a hydrolytically stable polyamide membrane having an open-pored, microporous and sponge-like support-layer structure, using a process involving thermally induced liquid-liquid phase separation. A solution of an aliphatic polyamide in a solvent system, comprising preferably a solvent and a non-solvent for the polyamide, is extruded to form a shaped object. After leaving the die, the shaped object is cooled by means of a cooling medium until phase separation occurs and the polymer-rich phase solidifies to form the membrane structure. The solution of the polyamide in the solvent system contains an antioxidant agent as a stabiliser for the polyamide which, together with the solvent system, is selected in a way that the antioxidant agent is essentially insoluble in the solvent system at the phase separation temperature. The invention also relates to a polyamide membrane with improved hydrolytic stability, characterised in that it contains an antioxidant agent as a stabiliser for improving hydrolytic stability.