Roland Hilke - Academia.edu (original) (raw)
Papers by Roland Hilke
Macromolecular Chemistry and Physics, 2003
Transfusion and Apheresis Science, 2001
On-line plasmapheresis using microporous membranes for ®ltration normally requires two external c... more On-line plasmapheresis using microporous membranes for ®ltration normally requires two external circulations (double treatment) before the detoxi®ed plasma can be returned to the patient. The duomodule, a new ®lter arrangement developed by our group, integrates both steps in one equipment module using only one external circuit. Separations of aqueous polyethylene glycol (PEG) solutions as well as human plasma were carried out using the duomodule arrangement. The results revealed a considerable decrease of higher molecular substances in the feed solutions and a signi®cant increase of these components in the permeate solution accumulated in the external compartment of the module. In conclusion, the duomodule arrangement seems to be an useful tool for the therapeutic apheresis. Ó
Formation of porous bilayer hollow fibre membranes
Macromolecular Symposia, 2002
Support membranes in bioartificial organs contact blood or plasma on one-side and adhesion depend... more Support membranes in bioartificial organs contact blood or plasma on one-side and adhesion dependent cells on the other side. Since membranes for biomedical applications, such as for haemodialysis, are optimised for blood contact and membranes for biotechnological ...
Macromolecular Chemistry and Physics, 2003
Hollow fiber membrane contactor for air humidity control: Modules and membranes
Journal of Membrane Science, 2006
The application of membrane contactors in air humidity control offers advantages over the convent... more The application of membrane contactors in air humidity control offers advantages over the conventional treatment methods, eg dew pointing by cooling (high energy consumption) and direct absorption (risk of air contamination by the absorbent). In gas/liquid membrane ...
Journal of Membrane Science, 2005
Polymeric membranes have been well established in many separation processes since the introductio... more Polymeric membranes have been well established in many separation processes since the introduction of a preparation technique generating asymmetric morphologies by Loeb and Sourirajan. If the separation layer of an asymmetric membrane is highly permeable, the support layer resistance can become significant. A highly asymmetric structure over the entire cross-section of a membrane is a prerequisite for the restriction of this resistance. With regard to hollow fiber membranes, a very open pore structure on the membrane surface opposite to the active layer is required.
Selection of microporous hydrophobic membranes for use in gas/liquid contactors: An experimental approach
Journal of Membrane Science, 2005
Contactors equipped with hydrophobic porous membranes were widely tested and operated in differen... more Contactors equipped with hydrophobic porous membranes were widely tested and operated in different separation processes. New applications, e.g. concentration of fruit juice or air conditioning, require a reliable separation of the two contacting phases at a higher level as for common applications in order to avoid product pollution by the liquid absorbent. The application of coated membranes as a liquid
The duomodule
Journal of Membrane Science, 2000
ABSTRACT The duomodule integrates two kinds of serially connected hollow fiber filters in a commo... more ABSTRACT The duomodule integrates two kinds of serially connected hollow fiber filters in a common module housing. The inner compartments of both filters are interlocked by a stable connection in which a throttle valve is integrated. The connected outer compartments of the filters are filled with an incompressible fluid. At a liquid flow in the inner compartment (primary circulation), a secondary circulation is generated due to a pressure drop between the filters. Filtration from the inner compartment to the outer compartments is initiated in the first filter, whereas refiltration takes place in the common outer compartment to the inner compartment in the second filter as a consequence of a transmembrane pressure reversal. In this paper, different duomodule arrangements are used for the fractionation of an aqueous dextran solution mixture to detect the duomodule separation ability and efficiency and to optimize the module construction. The fractionation ability and efficiency are related to the membrane characteristics. The results of the fractionation experiments demonstrate the separation function of the equipment. In the refiltration step, the transport direction goes from the outer to the inner membrane surface; therefore, an internal concentration polarization in the membrane wall can change the permeability and the separation behavior of the refiltration membrane. Accordingly, only symmetrically structured membranes or outside active refiltration membranes realize a desirable high fractionation ability and efficiency.
Journal of Membrane Science, 1999
On-line plasma detoxification requires two circulation: the separation of the plasma from the pat... more On-line plasma detoxification requires two circulation: the separation of the plasma from the patients blood, in a first circulation, and a plasma fractionation, in a second circulation, before the detoxified plasma returns back to the patient. These processes can be realised in one single step by use of a duofilter. The duofilter is a modular construction integrating two different hollow
ACS Applied Materials & Interfaces, 2013
We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform por... more We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes.
Macromolecular Chemistry and Physics, 2003
Transfusion and Apheresis Science, 2001
On-line plasmapheresis using microporous membranes for ®ltration normally requires two external c... more On-line plasmapheresis using microporous membranes for ®ltration normally requires two external circulations (double treatment) before the detoxi®ed plasma can be returned to the patient. The duomodule, a new ®lter arrangement developed by our group, integrates both steps in one equipment module using only one external circuit. Separations of aqueous polyethylene glycol (PEG) solutions as well as human plasma were carried out using the duomodule arrangement. The results revealed a considerable decrease of higher molecular substances in the feed solutions and a signi®cant increase of these components in the permeate solution accumulated in the external compartment of the module. In conclusion, the duomodule arrangement seems to be an useful tool for the therapeutic apheresis. Ó
Formation of porous bilayer hollow fibre membranes
Macromolecular Symposia, 2002
Support membranes in bioartificial organs contact blood or plasma on one-side and adhesion depend... more Support membranes in bioartificial organs contact blood or plasma on one-side and adhesion dependent cells on the other side. Since membranes for biomedical applications, such as for haemodialysis, are optimised for blood contact and membranes for biotechnological ...
Macromolecular Chemistry and Physics, 2003
Hollow fiber membrane contactor for air humidity control: Modules and membranes
Journal of Membrane Science, 2006
The application of membrane contactors in air humidity control offers advantages over the convent... more The application of membrane contactors in air humidity control offers advantages over the conventional treatment methods, eg dew pointing by cooling (high energy consumption) and direct absorption (risk of air contamination by the absorbent). In gas/liquid membrane ...
Journal of Membrane Science, 2005
Polymeric membranes have been well established in many separation processes since the introductio... more Polymeric membranes have been well established in many separation processes since the introduction of a preparation technique generating asymmetric morphologies by Loeb and Sourirajan. If the separation layer of an asymmetric membrane is highly permeable, the support layer resistance can become significant. A highly asymmetric structure over the entire cross-section of a membrane is a prerequisite for the restriction of this resistance. With regard to hollow fiber membranes, a very open pore structure on the membrane surface opposite to the active layer is required.
Selection of microporous hydrophobic membranes for use in gas/liquid contactors: An experimental approach
Journal of Membrane Science, 2005
Contactors equipped with hydrophobic porous membranes were widely tested and operated in differen... more Contactors equipped with hydrophobic porous membranes were widely tested and operated in different separation processes. New applications, e.g. concentration of fruit juice or air conditioning, require a reliable separation of the two contacting phases at a higher level as for common applications in order to avoid product pollution by the liquid absorbent. The application of coated membranes as a liquid
The duomodule
Journal of Membrane Science, 2000
ABSTRACT The duomodule integrates two kinds of serially connected hollow fiber filters in a commo... more ABSTRACT The duomodule integrates two kinds of serially connected hollow fiber filters in a common module housing. The inner compartments of both filters are interlocked by a stable connection in which a throttle valve is integrated. The connected outer compartments of the filters are filled with an incompressible fluid. At a liquid flow in the inner compartment (primary circulation), a secondary circulation is generated due to a pressure drop between the filters. Filtration from the inner compartment to the outer compartments is initiated in the first filter, whereas refiltration takes place in the common outer compartment to the inner compartment in the second filter as a consequence of a transmembrane pressure reversal. In this paper, different duomodule arrangements are used for the fractionation of an aqueous dextran solution mixture to detect the duomodule separation ability and efficiency and to optimize the module construction. The fractionation ability and efficiency are related to the membrane characteristics. The results of the fractionation experiments demonstrate the separation function of the equipment. In the refiltration step, the transport direction goes from the outer to the inner membrane surface; therefore, an internal concentration polarization in the membrane wall can change the permeability and the separation behavior of the refiltration membrane. Accordingly, only symmetrically structured membranes or outside active refiltration membranes realize a desirable high fractionation ability and efficiency.
Journal of Membrane Science, 1999
On-line plasma detoxification requires two circulation: the separation of the plasma from the pat... more On-line plasma detoxification requires two circulation: the separation of the plasma from the patients blood, in a first circulation, and a plasma fractionation, in a second circulation, before the detoxified plasma returns back to the patient. These processes can be realised in one single step by use of a duofilter. The duofilter is a modular construction integrating two different hollow
ACS Applied Materials & Interfaces, 2013
We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform por... more We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes.