Asymmetric PES porous membrane for virus removal and preparation method thereof

Abstract

The invention provides an asymmetric PES porous membrane for virus removal and a preparation method thereof, the porous membrane comprises a first porous surface, a second porous surface and a main body located between the first porous surface and the second porous surface, and the main body is internally provided with a non-directional zigzag passage; the porous membrane is a single-layer membrane; the average pore size of the PMI is 15-25 nm, the porosity is 70-85%, and the thickness is 40-150 microns; the part for intercepting the colloidal gold with the diameter of 20nm is an area which is 90-100% of the thickness of the main body from the first porous surface; the average pore size of the main body is continuously reduced in a gradient manner from a region close to one side of the first porous surface to a region close to one side of the second porous surface; the PES porous membrane is prepared only through a membrane casting solution, is integrally formed, does not need to be compounded, and is relatively simple in preparation process; meanwhile, the prepared PES filter membrane has a relatively strong interception effect on parvoviruses with the particle size of 20 nm or more, and meanwhile, a relatively high protein yield can be obtained, so that the requirements of practical application are met.

Description

technical field [0001] The invention relates to the technical field of membrane materials, in particular to an asymmetric PES porous membrane for virus removal and a preparation method thereof. Background technique [0002] Membrane technology is a new high-efficiency separation technology. Compared with traditional distillation and rectification technologies, it has the advantages of high separation efficiency, low energy consumption, and small footprint. The core of membrane separation technology is the separation membrane. Among them, the polymer filter membrane is a kind of separation membrane made of organic polymers as raw materials according to a certain process; among them, according to the different types of polymers, the polymer filter membrane can be subdivided into cellulose-based polymer filters. Membranes, polyamide polymer membranes, sulfone polymer membranes, polytetrafluoroethylene polymer membranes, etc.; in addition, they can be divided into microfiltratio...

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Problems solved by technology

[0004] For example, Chinese patent CN1759924B (applied by EMD Millipore) discloses a multilayer composite ultrafiltration membrane (attached Figure 19 and 20 ), the composite ultrafiltration membrane comprises at least one layer of the first porous film layer with the first face and the equivalent second face, and at least one layer of the second porous layer with the equivalent first face and the second face a film layer, the first layer superimposed with the connection of the second layer and having a porosity connection transition region from an equivalent first face of said second layer to an equivalent second face of said first layer, Wherein at least one of the layers is an asymmetric ultrafiltration membrane; the membrane structure formed in this way has a strong interception effect on parvovirus, and can obtain a higher protein yield at the same time, which meets the needs of practical applications; but There are also the following problems. First of all, since the filter membrane is a composite membrane, the pore size will suddenly change (reduce) during the transition from one layer to another layer, which will easily cause a large range of particle sizes to remain in the passage. At the interface of the layers produced by co-casting, this particle loading of the layer boundaries leads to a loss of service life of the filter, i.e. the service life is greatly reduced; and there is a risk of delamination / layer separation during pleating of the composite membrane

[0005] At the same time, U.S. Patent US20200238221A1 (applied by Sartorius Corporation) also discloses a porous single-layer polymer film, at least one major surface of the polymer film has a surface porosity of at least 40%, and the total porosity of the polymer film 0.8 to 1.4 times the surface porosity of at least 40%; and the polymer membrane has an asymmetry factor of 1.5 to 10; It is mainly used to filter viruses, proteins or macromolecules; however, the average pore size of the polymer membrane is large, and it can only retain large particles with a particle size of several hundred nanometers, but cannot retain small viruses with a particle size of 20nm

[0006] In addition, Chinese patent CN201580007740.0 (applied by Asahi Kasei Corporation) also discloses a virus-removing membrane, which contains cellulose, and is used to remove viruses from a protein-containing solution. The first porous surface, and the surface on the second side that discharges the permeate through the virus-removing membrane, the average pore size of the membrane is 13nm-21nm; the membrane has the advantages of high-efficiency virus retention and low protein adsorption rate At the same time, the membrane is a single-layer membrane, which does not have the disadvantages of sudden change in pore size and easy separation between membrane layers; but the filter membrane also has certain disadvantages; the virus removal membrane is prepared by the copper ammonia method , that is to add the film-forming material to the cuproammonia solution for various treatments. This preparation method not only pollutes the environment, but also is extremely dangerous, and is likely to cause great harm to the life safety of the research and development personnel; secondly, the prepared virus-removing film is hollow The fiber membrane has low compressive strength and is easy to be damaged, which leads to the relatively complicated preparation process of the virus removal membrane module and its filter; in addition, due to the low compressive strength of the virus removal membrane, the front and back of the membrane The pressure difference is small, so that the filtration speed is low, and the economic benefit per unit time is too low

[0007] In summary, the existence of the above problems also limits the development of virus-removing membranes to a certain extent.

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