Gkss-forschungszentrum Geesthacht Gmbh

Helmholtz-zentrum Geesthacht Zentrum Fur Material Und Kustenforschung Gmbh

Helmholtz-zentrum Hereon Gmbh

Helmholtz-zentrum Geesthacht Zentrum Fuer Material- Und Kuestenforschung Gmbh

Joachim Koll

Katrin Ebert

Volker Abetz

Jan Wind

Axel Wenzlaff

Detlev Fritsch

Gisela Bengtson

Bastian Ruffmann

Kirti Sankhala

Nazia Noor

Petra Merten

Maryam Radjabian

Kristian Buhr

Brigitte Lademann

Ulrich Handge

The present invention provides a coated hollow fiber membrane which has an isoporous inner skin and a porous outer support membrane, i.e. an inside-out isoporous composite hollow fiber membrane, and to a method of preparing such membranes. The coated hollow fiber membrane is prepared by a method comprising providing a hollow fiber support membrane having a lumen surrounded by the support membrane, and coating and the inner surface thereof by first passing a polymer solution of at least one amphiphilic block copolymer in a suitable solvent through the lumen of the hollow fiber support membrane and along the inner surface thereof, thereafter pressing a core gas stream through the lumen of the coated hollow fiber mebrane, and thereafter passing a non-solvent (precipitant) through the lumen of the coated hollow fiber membrane. In order to remove the solvent or solvents completely, the membranes are kept in water for 1-2 days and washed prior to use. In order to maintain the porosity of support membrane, membrane pretreatment is advantageous prior to coating which reduces the infiltration of block copolymer solution. The membranes are useful infiltration modules, in particular microfiltration modules, ultrafiltration modules, nano-filtration modules.

Method for preparing isoporous hollow fiber composite membranes

The present invention is directed towards a method for the preparation of macroporous or mesoporous polymer films in hollow fiber geometry. The method according to the present invention reliably produces macroporous or mesoporous homopolymer or copolymer films in hollow fiber geometry having an ordered porous structure. Preferably, the pores are isoporous. The method involves the purging or casting a polyol adjacent to a film forming polymer solution of at least one homopolymer or at least one copolymer in a suitable solvent while polyol diffuses in and then condenses out of the film forming solution before the solution is immersed into a coagulation bath. The methods also require the presence of a carrier solution or carrier substrate during spinning or casting. The method makes macroporous or mesoporous film formation possible with a single step processing method.

Macroporous or mesoporous polymer films in hollow fiber geometry

The invention relates to a process for producing a polymer membrane, the polymer membrane being produced from a solution, in particular a casting solution, comprising at least one first polymer. The invention further relates to a polymer membrane. The process of the invention is distinguished by the fact that a water-soluble second polymer and/or oligomer that forms phases in the solution is part of the solution. The polymer membrane of the invention, preferably produced by the process of the invention, has an oil flow rate, in particular of a refined edible oil, of greater than 200 l/mh bar at 60&#xb0; C.

Process for producing a polymer membrane, and polymer membrane

The invention relates to a composite with a separation-active membrane layer and a supporting membrane, a process for the production of the same and a process for using the same. The composite membrane according to the invention is distinguished by the fact that the separation-active membrane layer comprises a polymer hardened by electromagnetic radiation with wave length that is less than 800 nm and/or by electron beams. The process according to the invention is distinguished by the fact that a layer of a solution of a polymer that can be hardened by electromagnetic radiation with a wavelength that is less than 800 nm and/or by electron beams and an initiator substance is applied to a supporting membrane and subsequently is hardened by electromagnetic radiation and/or by electron beams. The use according to the invention serves to retain low molecular weight substances from organic solutions.

Composite membrane and process

The invention relates to a membrane for the separation of material mixtures by the principle of vapor permeation or pervaporation, in particular for the dewatering of organic solvents, comprising at least one support layer and at least one material-selective separation layer located thereon, and a method for production of such a membrane. The material-selective separating layer is made from polyvinyl alcohol, containing at least one metallic element and/or a derivative thereof. The method includes the addition of polyvinyl alcohol to a solvent, adding an organometallic compound to the solvent/polyvinyl alcohol mixture, and then applying the solvent/polyvinyl alcohol/organometallic compound mixture to the support layer as the material-selective separating layer.

Membrane for the separation of material mixtures and method for production thereof

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Schwarzenbek, Germany

Joachim Koll