Composite membrane and process
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.
1. A composite membrane with a separation-active membrane layer and a supporting membrane, wherein the separation-active membrane layer comprises a polymer hardened by at least one of electromagnetic radiation with a wavelength that is less than 800 nm and electron beams;
wherein the separation-active membrane layer comprises a silicone acrylate; and
wherein the silicone acrylate is selected from the group consisting of:
in which m and n are whole numbers and R is an alkyl functional group.
2. The composite membrane according to claim 1 , wherein the wavelength is less than 400 nm.
3. The composite membrane according to claim 1 , wherein the supporting membrane comprises polyacrylonitrile (PAN) and/or polyvinylidine fluoride (PVDF).
4. The composite membrane according to claim 1 , wherein the supporting membrane comprises an inorganic, porous material.
5. The composite membrane according to claim 4 , wherein the supporting membrane comprises an inorganic porous material selected from the group consisting of TiO 2 , ZrO 2 , Al 2 O 3 and a combination thereof.
6. A process for the production of a composite membrane according to claim 1 , wherein a layer of a solution of a polymer configured to be hardened by at least one of electromagnetic radiation with a wavelength that is less than 800 nm and electron beams and an initiator substance is applied to a supporting membrane and subsequently is hardened by at least one of: electromagnetic radiation and electron beams.
7. The process according to claim 6 , wherein the solution comprises a solvent that is vaporized before the hardening of the polymer.
8. The process according to claim 6 or 7 , wherein the supporting membrane has pores so small that the solution remains essentially on the surface of the supporting membrane.
9. A process comprising using a composite membrane according to claim 1 for retention of low-molecular weight substances from organic solutions.
10. The process according to claim 9 , further comprising using the composite membrane for at least one of the following:
purification of pharmaceutical substances, preparation of edible oils, separation of homogeneous catalysts from organic solutions, and preparation of petroleum fractions.
11. The composite membrane according to claim 10 , wherein the composite membrane is hydrophobic.
12. The composite membrane according to claim 1 , wherein the separation-active membrane layer is a nanofiltration membrane.
13. The composite membrane according to claim 1 , wherein the separation-active membrane layer is gas-tight in a dry state and only forms minimally small pores by swelling in solution.
14. The composite membrane to claim 1 , wherein the membrane has a separation limit in a separation range of between approximately 200 mw and approximately 1,500 mw.
15. The composite membrane according to claim 14 , wherein the separation limit is in a range of between approximately 200 mw and approximately 1,000 mw.
16. A process for the production of a composite membrane according to claim 1 , wherein a layer of a solution of a polymer, which is configured to be hardened by at least one of electromagnetic radiation with a wavelength that is less than 800 nm and electron beams, and an initiator substance is applied to a supporting membrane and subsequently is hardened by at least one of: electromagnetic radiation and electron beams;
wherein the composite membrane comprises a separation-active membrane layer and a supporting membrane;
wherein the separation-active membrane layer comprises the polymer; and
wherein the supporting membrane has pores so small that the solution remainsessentially on the surface of the supporting membrane.