CN1579599A - Charged microporous filtration membrane and affinity base membrane preparing method - Google Patents
Charged microporous filtration membrane and affinity base membrane preparing method Download PDFInfo
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- CN1579599A CN1579599A CN 03133628 CN03133628A CN1579599A CN 1579599 A CN1579599 A CN 1579599A CN 03133628 CN03133628 CN 03133628 CN 03133628 A CN03133628 A CN 03133628A CN 1579599 A CN1579599 A CN 1579599A
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Abstract
The invention relates to a microporous membrane, concretely speaking, an approach of producing charge microporous membrane and its affinity basement membrane. By weight, use cellulose acetate of 5-9 percent as basic material. Mix polycation compound of 0-15 percent in acetone/ dimethyl formamide of 45-70 percent. Use polyisocyanate of 0-0.8 percent as crosslinking agent to react. Add glycerin as additive. After knifing, absorb moisture in temperature of 30-70deg.C and relative humidity of over 95 percent and volatilize impregnant misphasing gel for 1-30 minutes. Finally form membrane and solidify. Merits of the invention lie in wide applied range, stable performance and normal reaction condition.
Description
Technical field
The present invention relates to microporous barrier, the preparation method of specifically a kind of CA/PEI blend charged microporous membrane and affine basement membrane.
Background technology
Microporous barrier is normally defined a sponge pore morphology thin-wall construction, open, has narrow pore-size distribution.The pore diameter range of microporous barrier has bigger porosity between the 0.01-10 micron, its traditional application is to remove tiny pollutant from liquid or gas medium.Granular as dust or bacterium, can remove by screening mechanism with microporous membrane filters.The filter efficiency of screening mechanism is controlled by the relative size of particle and membrane aperture, for reaching absolute trapped particles, satisfies higher requirement in medical treatment and the electronics industry with regard to the film that needs smaller aperture due.But some unfavorable characteristics are brought in the small-bore, and flow velocity, less contaminant trapping capacity, short life-span fall, hang down in promptly higher transmembrane pressure.Suspended particulate substance also can be removed by the absorption of electrodynamics mechanism, particle common in most of industrial practices has negative electrical charge because of suction-operated makes the surface, introduce positive charge by modification on the filter membrane surface, can from fluid, remove pollutant by the mechanism of Electrostatic Absorption, even grain diameter is littler than membrane aperture, the removal efficient of particle also has very big raising.Charged modified micro-pore film has higher rate of flow of fluid, longer service life than the film of the suitable performance of non-modified.
Existing charged microporous modification technology is carried out at a kind of hydrophobic polymer film usually, by flooding, apply afterwards crosslinked or in film forming solution, sneaking into polymer-modified and crosslinking agent, at high temperature carry out crosslinked method after the film forming and can make film surface possess hydrophilic property and have the charge that modified material brings.For example, document 1.US4798847 (Process for the preparation of hydrophilicmembranes and such membranes) is the base film material by hydrophobic polymer (PEI), prepare the microporous hydrophilic membrane that can be used for micro-filtration and ultra-filtration process with hydrophilic macromolecule PVP (PVP) blend, after film forming, it is carried out high-temperature process, carry out crosslinked to the PVP in the film, membrane aperture is 0.05-2 μ m, and pure water flux is 200-8000l/m
2/ hr/bar; Document 2.US4915839 (Process for surface modifying a microporous membrane) is by carrying out post processing with the solution impregnation of modifier (polyamide polymeric amine epichlorohydrin resin) after the film forming or add modified material system film in preparation liquid, in 110 ℃ modified material is carried out heat cross-linking again, prepare a kind of micropore nylon membrane of charged modification; Document 3.US5277812 (Inter-penetrating networkcharge modified microporous membrane) is by adding PEI and crosslinking agent 1 in the preparation liquid of polyether sulfone (PES) preparation miillpore filter, the 4-butanediol diglycidyl ether, the preparation miillpore filter, after film forming in 115 ℃ of heat cross-linkings, the charged modified micro-pore film for preparing hydrophilic interpenetrating polymer networks, aperture 0.03-0.8 μ m, pure water flux is 10Psi, 2.3-145ml/cm
2/ min; Document 4.US6045694 (Cationically charge-modified membranes) is the solution that dipping contains modifier ethoxy polyvinyl imines (HEPEI) and epoxychloropropane modified polyamine (RETEN) after the copolymer film forming of blend such as vinyl pyrrolidone and cation imidazolium compounds behind the base film material filming or in film liquid with the polysulfones, and heat cross-linking or radiation-induced crosslinking prepare lotus positive electricity Modified Membrane.They can effectively remove pollutant by the mechanism of Electrostatic Absorption from fluid; But because therefore hydrophobic polymer often can just not limit the degree of charged modification, and limit the film application of (as affine separation) in other respects with polymer-modified compatible; Adopt hydrophobic substrates, the non-specific adsorption effect is stronger.
Summary of the invention
The object of the invention is to provide a kind of modification degree height, the charged microporous membrane of applied range and the preparation method of affine basement membrane.
For achieving the above object, the technical solution used in the present invention is:
Hydrophilic film material and charged water soluble polymer blend system film: by weight percentage, with 5～9% cellulose acetates is the matrix material of system film, at 45～70% acetone/dimethyl formamide (or other solvent such as dimethylacetylamide, methyl-sulfoxide, the N-methyl pyrrolidone) in the mixed solvent, be blended into 0～15% polycationic compounds, in solution, react as crosslinking agent with 0～0.8% polyisocyanates, in solution, take place crosslinked, complex reactions such as grafting, make high polymer form the network structure that has a large amount of amino, add 15～30% glycerine again as additive, behind the knifing at 30～70 ℃, relative humidity is higher than moisture absorption and solvent flashing phase-splitting gel 1～30min in 95% atmosphere, film forming curing also exchanges out solvent fully in the immersion water, the polyvinyl imines also can be crosslinked in addition with crosslinking agents such as glutaraldehydes after film forming, by crosslinked, the grafting effect is present in the film matrix polymer charged polymer stabilizing, and passes through hydrogen bond, electrostatic force, twine the network structure that waits the formation polymer that interacts between macromolecular chain.
Gelling temp is preferably 45～55 ℃ behind the described knifing; Polycationic compounds can be polyvinyl imines (or polylysine), and cellulose acetate (matrix high polymer) is preferably cellulose diacetate; Used solvent is preferably acetone and dimethyl formamide mixed solvent, and the preferable weight ratio of acetone/dimethyl formamide is 1: 2～1: 1.8, and optimal proportion is 1: 1.9; Also can be by in cross-linking process, adding polyethylene glycol and ethylenediamine participation cross-linking reaction, so that the amplification terminal amino group content, should make the weight ratio between polyisocyanates, polyethylene glycol, ethylenediamine this moment is 7: 4: 1; Described poly-ammoniac compounds (blend macromolecule) is the polyvinyl imines, and its molecular weight is generally 2000-100,000; Be preferably 20000-100000 (or higher), the ratio of uncle's ammonia, secondary amine, tertiary amine is 1: 2: 1; After the film forming, prepared microporous barrier with the 1%-10% crosslinking agent (for example: glutaraldehyde, bis-epoxy reagent (1, the 4-butanediol diglycidyl ether), anhydrides crosslinking agent (PMA) etc.) solution carries out secondary cross-linking to polycationic compounds, strengthen the performance of film and improve membrane stability.
The present invention has following advantage:
1. the film applied range that makes.The structure of the made film of the present invention is the uniform spongelike structure of decorticate pore size distribution, hole connectedness with height, have slight asymmetric, charged electrostrictive polymer constitutes uniform electric charge network and distributes from forming more equally distributed sites of positive charge on the membrane structure basis in the aqueous solution, has good hydrophilicity and biocompatibility, the primary amino radical, the imido grpup that contain more amount, membrane aperture is 0.1-3 μ m, and porosity is 60-85%, and pure water flux (520mmHg) can reach 2-60ml/cm
2/ min, terminal amino group content can reach 60-600 μ mol/g film, and electric charge site, disassociation back is 0.24-2.4meq/g film (its typical membrane structure electromicroscopic photograph is shown in Fig. 1～4).Can be used for removing the various electronegative fine grained pollutant in the liquid medium,, improve filter efficiency as bacterium, virus (comprising SARS virus), endotoxin etc.; Can be used for the filtration of the ultra-pure water of used in electronic industry, greatly strengthened filter efficiency; The primary amino radical that it had is suitable for the affine modification under the temperate condition, as the basement membrane (can utilize amino key and the affinity ligand of the PEI of introducing, key and mild condition react easy) of affinity membrane; A large amount of uncle's ammonia, imines, tertiary amine chela and the Cu that also can utilize on the film to be had
2+, Zn
2+Prepare the purifies and separates that the immobilized metal affinity membrane is used for albumen Deng metal ion; Select CA can avoid the non-specific adsorption that causes as matrix material with hydrophobic polymer as matrix polymer to albumen etc., be suitable for the application in bio-separation, in the pollutant processes such as endotoxin in removing protein solution remarkable advantages is arranged, also make its application obtain sound assurance as affine basement membrane.
2. the film properties that makes is stable.Preparing product of the present invention is the another kind of charged polymer (water soluble polymer polyvinyl imines) that evenly distributes in film surface and base film material (cellulose acetate), by in film liquid, carrying out crosslinked, graft reaction, charged polymer stabilizing is present in the film matrix polymer, forms the network structure of polymer.
3. reaction condition gentleness.The present invention adds the crosslinking agent polyisocyanates to carry out crosslinked back preparation preparation liquid under the normal temperature in cellulose acetate and polyvinyl imines blend solution, prepare charged modified microfiltration membrane; The used film forming method is moisture absorption and a solvent flashing under higher temperature, the super-humid conditions, immerses film-forming in the water again; Can be by adjusting aperture and the porosity that glycerine consumption, PEI blending amount, dosage of crosslinking agent are come controlling diaphragm in the preparation liquid; With polyisocyanates (polymer of methyl diphenylene diisocyanate) is that crosslinking agent has stable bond polycationic compounds (as: PEI) molecule and have the function that promotes pore in film forming procedure.
Description of drawings
Fig. 1 is the typical membrane structure upper surface of a present invention A electromicroscopic photograph;
Fig. 2 is the typical membrane structure lower surface of a present invention B electromicroscopic photograph;
Fig. 3 is the typical membrane structure section of a present invention C electromicroscopic photograph;
Fig. 4 amplifies the D electromicroscopic photograph for the typical membrane structure section of the present invention.
The specific embodiment
Embodiment 1
With the cellulose diacetate of percentage by weight 7%, dimethyl formamide 43.8%, acetone 22.7%, glycerine 26.5%, the preparation preparation liquid, with film liquid blade coating on glass plate, thick 500 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 8min in 95% the air, treats that phase-splitting finishes the back substantially and immerse in the water, makes exchange of solvent complete and remove unnecessary component, the cured film structure makes dull and stereotyped micro-filtration membrane.
Embodiment 2
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, polyethylene glycol (molecular weight 1000), ethylenediamine, the preparation Polymer Solution, 7% solution (DMF and acetone half and half are solvent) with polyisocyanates (polymer of methyl diphenylene diisocyanate), press polyisocyanates, polyethylene glycol, the ethylenediamine weight ratio is that 10: 4: 1 amount adds, add glycerine preparation preparation liquid behind the polymerization crosslinking, its final weight percentage is cellulose diacetate 6.9%, dimethyl formamide 43.2%, acetone 22.5%, the 50%PEI aqueous solution 1% has added 0.12% polyethylene glycol (molecular weight 1000), 0.03% ethylenediamine, 0.34% polyisocyanates, glycerine 23.8%, with film liquid blade coating on glass plate, thick 500 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
Embodiment 3
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, preparation blended polymer solution, its final weight percentage is cellulose diacetate 7%, dimethyl formamide 45.7%, acetone 23.7%, the 50%PEI aqueous solution 0.5%, glycerine 23.1%, with film liquid blade coating on glass plate, thick 400 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
Embodiment 4
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, the preparation Polymer Solution, 7% solution (DMF and acetone half and half are solvent) with polyisocyanates (polymer of methyl diphenylene diisocyanate), pressing polyisocyanates and 0.23: 1 amount of 50% polyvinyl imines weight ratio adds, add glycerine preparation preparation liquid behind the polymerization crosslinking, its final weight percentage is cellulose diacetate 7%, dimethyl formamide 44.8%, acetone 23.2%, 50%PEI amount of aqueous solution used 1%, glycerine 23.7%, with film liquid blade coating on glass plate, thick 400 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
Embodiment 5
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, preparation is as embodiment 4 crosslinked preceding Polymer Solutions, 7% solution (DMF and acetone half and half are solvent) with polyisocyanates (polymer of methyl diphenylene diisocyanate), pressing polyisocyanates and 0.23: 1 amount of 50% polyvinyl imines weight ratio adds, crosslinked back adds 50%PEI and glycerine preparation preparation liquid, its final weight percentage is cellulose diacetate 7%, dimethyl formamide 43.8%, acetone 22.8%, the 50%PEI aqueous solution 1.6%, polyisocyanates consumption 0.25%, glycerine 24.5%, with film liquid blade coating on glass plate, thick 400 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
Embodiment 6
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, preparation is as embodiment 4 crosslinked preceding Polymer Solutions, 7% solution (DMF and acetone half and half are solvent) with polyisocyanates (polymer of methyl diphenylene diisocyanate), pressing polyisocyanates and 0.23: 1 amount of 50% polyvinyl imines weight ratio adds, crosslinked back adds 50%PEI and glycerine preparation preparation liquid, its final weight percentage is cellulose diacetate 7%, dimethyl formamide 43.8%, acetone 22.8%, the 50%PEI aqueous solution 2%, polyisocyanates consumption 0.25%, glycerine 24.1%, with film liquid blade coating on glass plate, thick 400 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
Embodiment 7
Dimethyl formamide/acetone soln with cellulose diacetate adds the 50%PEI aqueous solution, preparation is as embodiment 4 crosslinked preceding Polymer Solutions, 7% solution (DMF and acetone half and half are solvent) with polyisocyanates (polymer of methyl diphenylene diisocyanate), pressing polyisocyanates and 2: 3 amount of 50% polyvinyl imines weight ratio adds, crosslinked back adds 50%PEI and glycerine preparation preparation liquid, its final weight percentage is cellulose diacetate 6.9%, dimethyl formamide 43.2%, acetone 22.4%, polyisocyanates consumption 0.7%, 50%PEI amount of aqueous solution used 2.8%, glycerine 24%, with film liquid blade coating on glass plate, thick 400 μ m, in 50 ℃, relative humidity is higher than moisture absorption precipitation 2min in 95% the air.All the other conditions are with embodiment 1.
The main performance of the made film of embodiment 1-7 sees the following form
| Embodiment | 520mmHg pure water flux (ml/cm 2/min) | Bubble point pressure (MPa) | Amino content (μ mol/g film) | Nitrogen content (%) |
| ????1 | ??????29.38 | ????0.11 | ????0 | |
| ????2 | ??????12.58 | ????0.35 | ????263.97 | |
| ????3 | ??????21.61 | ????0.26 | ????57.50 | |
| ????4 | ??????18.28 | ????0.29 | ????179.59 | |
| ????5 | ??????9.22 | ????0.19 | ????248.12 | ???1.61 |
| ????6 | ??????4.78 | ????0.26 | ????286.45 | ???1.81 |
| ????7 | ??????9.82 | ????0.21 | ????345.39 | ???2.68 |
The comparative example that invention is relevant:
It is the preparation method that the base film material is sneaked into the lotus positive electricity Modified Membrane of charged modifier that US4915839, US5277812, US6045694 have proposed with nylon, PES, PS respectively, all after film forming, utilize epoxide group and amino in the modifier to carry out heat cross-linking, be used for the removal of solution pollutant.It is the base film material that the present invention then adopts cellulose acetate, in preparation liquid, sneak into charged modified high-molecular and crosslinking agent, after in Polymer Solution, carrying out ambient cross-linking, add other additives and join preparation liquid, the miillpore filter of preparation lotus positive electricity modification, to adopt hydrophilic cellulose acetate be the base film material to the non-specific adsorption of protein and other much smaller than nylon, hydrophobic material PES and PS, be fit to the requirement of biological separation application, and can utilize made charged microporous barrier as affine basement membrane, the immobilization aglucon is used for affine separation.
Claims (10)
1. the preparation method of a charged microporous membrane and affine basement membrane is characterized in that:
By weight percentage, with 5～9% cellulose acetates is the matrix material of system film, in 45～70% acetone/dimethyl formamide mixed solvent, be blended into 0～15% polycationic compounds, in solution, react as crosslinking agent with 0～0.8% polyisocyanates, add 15～30% glycerine again as additive, be higher than moisture absorption and solvent flashing phase-splitting gel 1～30min in 95% atmosphere at 30～70 ℃, relative humidity behind the knifing, film forming is solidified.
2. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: gelling temp is 45～55 ℃ behind the described knifing.
3. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: described polycationic compounds is polyvinyl imines or polylysine.
4. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: described cellulose acetate is a cellulose diacetate.
5. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: the weight ratio of acetone and dimethyl formamide mixed solvent is 1: 2～1: 1.8.
6. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: described poly-ammoniac compounds is the polyvinyl imines, and its molecular weight is 2000～100000.
7. according to the preparation method of described charged microporous membrane of claim 7 and affine basement membrane, it is characterized in that: the molecular weight of described polyvinyl imines is 20000～100000, and the ratio of uncle's ammonia, secondary amine, tertiary amine is 1: 2: 1.
8. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: add polyethylene glycol and ethylenediamine participation cross-linking reaction in cross-linking process, the weight ratio between polyisocyanates, polyethylene glycol, ethylenediamine is 7: 4: 1 at this moment.
9. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: after the film forming, prepared microporous barrier carries out secondary cross-linking with 1～10% cross-linking agent solution to polycationic compounds.
10. according to the preparation method of described charged microporous membrane of claim 1 and affine basement membrane, it is characterized in that: glycerine/CA weight ratio is 3: 1～3.8: 1.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101596382B (en) * | 2009-04-28 | 2011-05-11 | 无锡荣和环保设备有限公司 | Preparation method of charge positive charge filter material and application thereof |
| CN103240004A (en) * | 2013-05-15 | 2013-08-14 | 北京碧水源膜科技有限公司 | Charged nanofiltration membrane and preparation method thereof |
| CN110944737A (en) * | 2017-07-19 | 2020-03-31 | 甘布罗伦迪亚股份公司 | Filtration membrane and device |
| CN115109301A (en) * | 2021-03-18 | 2022-09-27 | 四川大学 | Preparation method of hollow open cellulose diacetate microspheres |
-
2003
- 2003-08-01 CN CN 03133628 patent/CN1256174C/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101596382B (en) * | 2009-04-28 | 2011-05-11 | 无锡荣和环保设备有限公司 | Preparation method of charge positive charge filter material and application thereof |
| CN103240004A (en) * | 2013-05-15 | 2013-08-14 | 北京碧水源膜科技有限公司 | Charged nanofiltration membrane and preparation method thereof |
| CN103240004B (en) * | 2013-05-15 | 2015-04-15 | 北京碧水源膜科技有限公司 | Charged nanofiltration membrane and preparation method thereof |
| CN110944737A (en) * | 2017-07-19 | 2020-03-31 | 甘布罗伦迪亚股份公司 | Filtration membrane and device |
| CN110944737B (en) * | 2017-07-19 | 2022-04-15 | 甘布罗伦迪亚股份公司 | Filtration membrane and device |
| CN115109301A (en) * | 2021-03-18 | 2022-09-27 | 四川大学 | Preparation method of hollow open cellulose diacetate microspheres |
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