GB1581194A - Method of producing solute-rejecting dynamic membrane filters and filters including such membranes - Google Patents
Method of producing solute-rejecting dynamic membrane filters and filters including such membranes Download PDFInfo
- Publication number
- GB1581194A GB1581194A GB21681/78A GB2168178A GB1581194A GB 1581194 A GB1581194 A GB 1581194A GB 21681/78 A GB21681/78 A GB 21681/78A GB 2168178 A GB2168178 A GB 2168178A GB 1581194 A GB1581194 A GB 1581194A
- Authority
- GB
- United Kingdom
- Prior art keywords
- silica particles
- solute
- silica
- filter
- dynamic membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000012528 membrane Substances 0.000 title claims description 37
- 238000000034 method Methods 0.000 title claims description 25
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 74
- 239000002245 particle Substances 0.000 claims description 27
- 239000000758 substrate Substances 0.000 claims description 17
- 238000000151 deposition Methods 0.000 claims description 12
- 239000000377 silicon dioxide Substances 0.000 claims description 12
- 229920000867 polyelectrolyte Polymers 0.000 claims description 10
- 229920002125 Sokalan® Polymers 0.000 claims description 9
- 239000006185 dispersion Substances 0.000 claims description 9
- 239000004584 polyacrylic acid Substances 0.000 claims description 9
- 239000011148 porous material Substances 0.000 claims description 9
- 239000004115 Sodium Silicate Substances 0.000 claims description 8
- 229910021485 fumed silica Inorganic materials 0.000 claims description 8
- 239000007788 liquid Substances 0.000 claims description 8
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 8
- 230000008021 deposition Effects 0.000 claims description 7
- 229920001400 block copolymer Polymers 0.000 claims description 4
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 3
- 230000007062 hydrolysis Effects 0.000 claims description 3
- 238000006460 hydrolysis reaction Methods 0.000 claims description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- VXEGSRKPIUDPQT-UHFFFAOYSA-N 4-[4-(4-methoxyphenyl)piperazin-1-yl]aniline Chemical compound C1=CC(OC)=CC=C1N1CCN(C=2C=CC(N)=CC=2)CC1 VXEGSRKPIUDPQT-UHFFFAOYSA-N 0.000 claims description 2
- 238000001556 precipitation Methods 0.000 claims description 2
- 239000005049 silicon tetrachloride Substances 0.000 claims description 2
- 239000002244 precipitate Substances 0.000 claims 3
- 239000004793 Polystyrene Substances 0.000 claims 2
- 229920002223 polystyrene Polymers 0.000 claims 2
- BDHFUVZGWQCTTF-UHFFFAOYSA-N sulfonic acid Chemical compound OS(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-N 0.000 claims 2
- 239000000243 solution Substances 0.000 description 14
- 230000004907 flux Effects 0.000 description 11
- 239000003921 oil Substances 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 7
- 238000001816 cooling Methods 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 229920002307 Dextran Polymers 0.000 description 5
- 229910052799 carbon Inorganic materials 0.000 description 5
- 239000000839 emulsion Substances 0.000 description 5
- 238000001914 filtration Methods 0.000 description 4
- 239000012466 permeate Substances 0.000 description 4
- 239000000654 additive Substances 0.000 description 3
- 230000000996 additive effect Effects 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 239000007832 Na2SO4 Substances 0.000 description 2
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000004530 micro-emulsion Substances 0.000 description 2
- 229920000136 polysorbate Polymers 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 description 2
- 235000011152 sodium sulphate Nutrition 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- 238000002525 ultrasonication Methods 0.000 description 2
- 229920003169 water-soluble polymer Polymers 0.000 description 2
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- 229910004809 Na2 SO4 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000010425 asbestos Substances 0.000 description 1
- 238000011001 backwashing Methods 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 229910001410 inorganic ion Inorganic materials 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 150000002500 ions Chemical group 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- ZQGZJHCODJQNCB-UHFFFAOYSA-N non-2-ynal Chemical compound CCCCCCC#CC=O ZQGZJHCODJQNCB-UHFFFAOYSA-N 0.000 description 1
- 229920000620 organic polymer Polymers 0.000 description 1
- 239000010451 perlite Substances 0.000 description 1
- 235000019362 perlite Nutrition 0.000 description 1
- 235000019422 polyvinyl alcohol Nutrition 0.000 description 1
- 229910052895 riebeckite Inorganic materials 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/14—Dynamic membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0079—Manufacture of membranes comprising organic and inorganic components
- B01D67/00793—Dispersing a component, e.g. as particles or powder, in another component
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/14—Dynamic membranes
- B01D69/141—Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
- B01D69/148—Organic/inorganic mixed matrix membranes
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Dispersion Chemistry (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Description
(54) METHOD OF PRODUCING SOLUTE-REJECTING
DYNAMIC MEMBRANE FILTERS AND FILTERS INCLUDING
SUCH MEMBRANES
(711) We, YEDA RESEARCH & DEVELOPMiENtT CO. LTD., a Company of
Israel of P.O. Bot 95 Rehovot, Israel, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it lis to be performed, to be particularly described in and by the following statement : - The present invention relates to methods of producing solute-rejecting dynamic membrane filters, and also to filters including such membranes.
Solute-rejecting dynamic membrane filters are well known, for example as described in
U.S. Patent 3,577,339 of May 4, 19711. Such known filters include a porous substrate (e.g., porous metal, ceramic, of carbon) having a relatively large pore size (e.g., 5 to 50 microns in diameter) on which has been deposited a bed of smaller particles (e.g. in the range of 0.01-100 microns in diameter) of an inert material, for example diatonaceous earth, perlite, asbestos fibres, cellulose fibres, dried silica gel, and carbon. The thin bed of particles functions as a finely pored body and remains uniformly distnibuted even when deposited in the presence of a cross-flow velocity parallel to the surface of the membrane. The thickness of the bed is a function of the cross-flow velocity, and therefore, it is often useful to deposit the bed under turbulent flow conditions. The filters are easily removed by backwashing, and are easily re-established by depositing a new bed of the particles on the porous substrate.
In order to make the known dynamic membrane filters solute-rejecting, it is generally necessary to include a solute-re1ectiing additive; for example, a neutral organic polymer, polyelectrolyte, organic Of inorganic ion exchanger, Of hydrous metal oxide, as described in column 3, lines 12-23 of the above-oited patent.
Moreover, it is generally difficult, in the known procedures, to tailor the produced dynamic membrane to have a preselected molecular weight cut-off characteristic.
An object of the present invention is to provide a novel method of producing a soluterejecting dynamic membrane filter, and also to provide a filter including such membrane, which method and filter have advantages in the above respects.
According to one aspect of thi present invention, there is provided a method of producing a solute-rejecting dynamic membrane filter, comprising depositing a bed of silica particles on a porous substrate having a pore size of 0.025-3 microns, the silica particles being substantially spherical and uniform and having a nominal particle diameter of 20~80 A.
According to another aspect of the present invention, .there is also provided a soluterejecting dynamic membrane filter, comprising: a porous substrate having a pore size of 0.025-3 microns, and a bed of silica particles deposited thereon, said silica particles being substantially spherical and uniform, and having a nonainal particle diameter of 20-80 A.
It has been found that when the dynamic membrane filter is formed with a porous sub strate of the above range, and particularly including silica particles in the above range of sizes (both of which ranges are below those specified in the above-cited U.S. Patent), a solute-rejecting membrane lis produced without the need for adding a solute-rejecting additive as described in the above-cited U.S. Patent (e.g. Column 3, lines 12-23). Moreover, it has been found that the molecular weight cutoff characteristic of the dynamic filter can be preselected over a snide range by merely selecting the pressure applied during the deposition of the silica particles.
The pressure at which the deposition is carried out may generally vary from 0.5 to 70 atmospheres, depending on the selectivity desired, the higher pressures producing a lower molecular weight cut-off characteristic, and the lower pressures producing a higher molecular weight cutoff characteristic. By utilizing the smaller particles (below 40 Ä) together with those of larger size (between 70-80 ), it is possible to obtain greater solute selectivity at a lower operating pressure. This may be carried out by first depositing a layer of particles of a size range of 70-80 followed by a second deposition of particles of size range of less than 40 , e.g. 20-40 or 30-40 . The pH should be in the range 2-9.5, with the preferred pH=4, while the ionic strength of the solution should be less than 0.3M, and always below that required to cause coagulation of the silica particles.
It has also been found that by including a polyelectrolyte with the silica particles in the liquid applied to the substrate, an increase is produced in the rejection of small negatively
charged solute present in the liquid being filtered. This makes the filter particularly useful in removing the charged surfactants in oil emulsions. It has also been found that by using a polyelectrolyte and then further treating the
dynamic membrane with another water soluble polymer (e.g. a solution of polyvinyl), the pro
duct flux is maintained relatively constant over
a substantial period of time, besides increasing
the selectivity of the membrane in salt rejection.
The foregoing advantages of the present
invention will be better illustrated by the
specific examples set forth below.
Generally, the formation, from silica of a
dynamic membrane having solute rejecting properties is carried out staring with silica
particles which consist of or include furred
silica or silica precipitated from sodium silicate.
The fumed silica can be obtained by vapour phase hydrolysis of silicon tetrachloride. The
silica is then desirably formulated as an
aqueous dispersion, preferably in the following
manner: a very fine dispersion of silica par
ticles, whose nominal particle diameter is be
tween 20-80 and whose concentration is
between 5-5000 ppm. is prepared in ion
exchanged, filtered water. This dispersion may
be prepared either by ultrasonication of fumed
silica particles, or by treatment of a solution
of sodium silicate to a pH between 2-9.5,
and allowing the precipitated particles to grow
to a well defined size, as known in the prior
art. This solution is then filtered through a
filter medium substrate possessing small umi- form pores in such a way as to lead to the
deposit of a thin uniform bed of particles. The
pores of the substrate may be from 0.025 to
3 microns, with the preferred range being be
tween 0.1-1 microns, although is may
depend on the type of filter medium used.
"Cab-O-Sil" is a Registered Trade Mark.
EXAMPLE 1.
A dispersion of 500 ppm fumed silica, par
ticle size 70 (Cab-O-Sil EH-5 Cabot Corp.)
was made up in ion-exchanged, filtered water
at pH=7 by ultrasonication for 90 min. in a 50 W "Bransonic" ultrasonic bath. The solution was filtered for 30 minutes at a cross flaw rate of 0.5 l/min. and a pressure of 25 psi. through a tubular Selas ceramic support
(Flotronics Corp.) containing pores 0.27 microns in diameter. The dynamic membrane formed displayed 85% rejection of a 2x106 g/M molecular weight (0.1%) dextran solution, but only 24% rejection for a dextran fraction of SX106 g/M and 6.5% rejection for a dextran fraction of 7 X 104 g/M molecular weight. The solute rejection of a 10-3
N Na2 SO4 salt solution was found to be 40%, which demonstrated that the membrane also rejected the samll mol.wt. ionic solutes. The filtration of a 3% commercial cooling oil emulsion (Trucut EP/CW) gave 90% rejection of total organic carbon (TOC). Flux decline was also tested with the cooling oil at a pressure of 30 PSI, the initial flux was 12 cm/hr, which flux decreased to 8 cm/hr over a period of
80 hrs. For a second commercial cooling oil
(Chimcool) which forms transparent microemulsions, the TOC rejection was 67%, and the flux was 10-12 cm/hr.
It will thus be seen that the membrane made as described above in Example 1 has soluterejecting properties even without the addition of a solute-rejecting additive such as described in the above-cited U.S. Patent.
To show the criticality of the above range of particle diameters, the same procedure as described above in Example 1 was carried out but with silica particles of 120 (Cab-O-Sil
M5). The filter produced exhibited zero rejection of 2x106 g/M Mol.Wt. (0.1% dextran solution), as compared to 85% when silica particles of a size of 70 A were used, as des cribed in Example 1.
As noted above, the molecular weight cut-off characteristic of the filter produced can be varied by merely selecting the formation pressure of the silica particle bed, a filter having a higher solute molecular weight cut-off being produced by using a formation pressure of the order of 1-5 atmospheres, and a filter having a lower solute molecular weight cut-off being produced by using a formation pressure of the order of 5-50 atmospheres. This may be illustrated by the following example:
EXAMPLE 2.
Silica dispersion and filtration conditions were identical to Example 1 except that formation pressure was raised to 120 psi. Rejection of a 0.1% solution of a 5x105 g/M dextran fraction was 100%, while rejection of 1.1x105 g/M fraction was 92% and that of 7x104 g/M fraction was 65%.
As also noted above, greater solute selectivity can be obtained at a lower operating pressure by first depositing larger silica particles (e.g., 70-80 ) and then smaller silica particles (e.g., 20-40 ). This is illustrated by the following example.
EXAMPLE 3.
A dynamic membrane was simultaneously prepared from a solution as in Example 1 at a feed cross-flow rate of 1 I/min and a pressure of 15 psi, on a 0.45y Acropor flat sheet porous support (Gelman Inst. Corp.) and a 0.27/ Selas ceramic tube. This was followed by a second filtration, at the same pressure and cross-flow rate, of a dispersion of 250 ppm silica prepared by passing 1 cc of a 25% aqueous solution of sodium silicate down an ion-exchange column and diluting to 11, the final solution having a pH of 8.5, adjusted to pH=4 with HCl. When tested with 10-3 N
Na2SO4 at a pressure of 15 psi and a circulation flow rate of 1-31/rain, the membrane formed on both porous supports showed 85% rejection of salt, as measured by permeate solution conductance and a permeate flux of 13 em/br (as compared to 40% in Example 1). The same membranes displayed 93% rejection of Total Organic Carbon (TOC) of a 3% commercial cooling oil Emulsion (Trucut
EP/CW) with the same permeate flux. For the micro-emulsion of a seond commercial cooling oil (Chimcool), the dynamic membranes displayed TOC rejection of 80% (as compared to 67% in Example 1) with a permeate flux between 9-12 cm/hr.
The above example also illustrates the use of silica particles produced by precipitation from a sodium silicate solution, the particle size being about 30-40 .
As further noted above, the rejection of small negatively charged solutes present in the medium can be increased by including a polyelectrolyte in the silica particle dispersion producing .the silica ;bed. This makes the filter particularly useful in removing the charged surfactants in oil emulsions. This feature is illustrated by the following example: EXAMPLE 4.
As Example 1, except that the concentration of fumed silica was only 250 ppm; and 1000 ppm of a block copolymer polyelectrolyte was added to the dispersion, which was adjusted ,to pH=2. The block copolymer comprised polyacrylic acid (1104 molecular weight) co valency bonded to polystyreneulphonic acid (4x504 molecular weight) covalently bonded to a second block of polyacrylic acid (104 molecular weight). When a 3% emulsion of a commercial cooling oil (Trucut EP/CW) was filtered, the flux obtained was 10 cm/hr, and the rejection of Total Organic Carbon (TOC) was 99% (as compared to 90% in Example 1).
The selectivity of the membrane can be further increased and moreover its product flux
can be maintained substantially constant over a long period of time, by an additional watersoluble polymer treatment of the membrane.
This is illustrated by the following example.
EXAMPLE 5.
As in Example 1, except that the silica concentration was 250 ppm, and 500 ppm of polyacrylic acid (molecular weight 1-3 X 10') adjusted to pH=2. The pressure of formation was 26 atmospheres. After formation of the dynamic membrane, a further treatment was given with a solution of 5 ppm of polyvinylalcohol (Dupont grade 52-22, molecular weight 150,000, degree of hydrolysis = 87%) at a pH=4. The rejection of a solution of 10-3 N Na2SO4 was 100% (as compared to the case of Example 1 in which it was only 40%). For a membrane of similar composition formed at 7 atmospheres, the filtration of the 3% commercial cooling oil of Example 3 gave 95% rejection of TOC (as compared to 90% in Example 1), and maintained its initial flux of 15 cm/hr for 80 hours with no significant decline.
While the invention has been illustrated by several examples, it will be appreciated that many variations, modifications and other applicautions of the invention may be made.
Claims (27)
1. A method of producing a solute-rejecting dynamic membrane filter, comprising depositing a bed of silica particles on a porous substrate having a pore size of 0.025-3 microns, the silica particles being substantially spherical and uniform and having a nominal particle diameter of 20-80 A.
2. The method of Cla.im 1, wherein said silica particles consist of or include fumed silica.
3. The method of Claim 2, wherein said fumed silica particles are produced by vapour phase hydrolysis of silicon tetrachloride.
4. The method of Claim 1, wherein said silica particles consist of or include the precipi- tate from a solution of sodium silicate.
5. The method according to any one of
Claims 1-4, wherein the bed of silica particles is deposited by dispersing the particles in a
Liquid and applying said liquid to the porous substrate at a preselected pressure of 0.5-70 atmospheres said pressure having been preselected according to the desired solute molecu- lar weight cut-off for the filter.
6. The method according to Claim 5, wherein the silica particle dispersion is applied to the substrate at a pressure in the order of 1-5 atmospheres to produce a relaltively high solute molecular weight cut-off.
7. The method according to Claim 5, wherein the silica particle dispersion is applied to the substrate at a pressure in the order of 5-50 atmospheres to produce a relatively low solute molecular weight cut-off.
8. The method according to any one of
Claims 1-7, wherein the liquid in which the
silica particles are dispersed is water.
9. The method according to any one of
Claims 5-8, wherein the bed of silica particles is deposited in two steps, the first step being to apply to the porous substrate a liquid including silica particles having a nominal particle diameter of 70-80 , the second step being to apply to the so-treated porous substrate a liquid including silica particles having a nominal particle diameter of 20-40 A.
10. The method of Claim 9, wherein, in the first step the silica particles are fumed silica, and in the second step the silica particles are produced by precipitation from a solution of sodium silicate.
11. The method according to any one of
Claims 5-10, wherein a polyelectrolyte is included with the silica particles in the liquid applied to the substrate.
12. The method according to Claim 1;1, wherein said polyelectrolyte is a block copolymer comprising polyacrylic acid covalently bonded to polystyrene sulphonic acid covalently bonded to a second block of polyacrylic acid.
13. The method according to Claim 11, wherein said polyelectrolyte is polyacrylic acid.
14. The method according to any one of
Claims 11--13, including the further step of treating the dynamic membrane with a solution of polyvinyl alcohol.
15. A solute-rejecting dynamic membrane fitter, comprising a porous substrate having a pore size of 0.025-3 microns, and a bed of silica particles deposited thereon, said silica particles being substantially spherical and uniform, and having a nominal particle diameter of 20-80 .
16. A filter according to Claim 15, wherein said silica particles consist of or include fumed silica.
17. A filter according to Claim 15, wherein said silica particles consist of or include the precipitate from a solution of sodium silicate.
118. A filter according to Claim 15, wherein the bed o silica particles consists d or includes a first deposition of silica particles having a nominal particle diameter of 70-80 , and a second deposition of silica particles having a nominal particle diameter of 20-40 A.
19. A filter according to Claim 18, wherein the silica particles of the first deposition are fulmed silica, and the silica particles in the second deposition are the precipitate from a solution of sodium silicate.
20. The filter according to any one of Claims 15-19, wherein a polyelectrolyte is included in the bed of silica particles.
21. The filter according to Claim 20, wherein said polyclectrolyte is a block copolymer comprising polyacrylic acid covalently bonded to polystyrene sulphonic acid covalently bonded to a second block of polyacrylic acid.
22. The filter according to Claim 20, wherein said polyelectrolyte is polyacrylic acid.
23. The filter according to any one of Claims 20-22, wherein the dynamic membrane has been treated with a solution of polyvinyl alcohol.
24. The filter according to any one of Claims 15-23, wherein the substrate has a pore size of 0.1-1 micro.
25. A method of producing a solute-rejecting dynamic membrane filter substantially as described with reference to the disclosed examples.
26. A solute-rejecting dynamic membrane filter substantially as described with reference to the disclosed examples.
27. A solute-rejecting dynamic membrane filter when produced by the method of any of Claims 1 to 14 or 25.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IL52462A IL52462A (en) | 1977-07-05 | 1977-07-05 | Method of producing solute rejecting dynamic membrane filters and filters including such membranes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1581194A true GB1581194A (en) | 1980-12-10 |
Family
ID=11049637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB21681/78A Expired GB1581194A (en) | 1977-07-05 | 1978-05-23 | Method of producing solute-rejecting dynamic membrane filters and filters including such membranes |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5414377A (en) |
| DE (1) | DE2825699A1 (en) |
| FR (1) | FR2408376A1 (en) |
| GB (1) | GB1581194A (en) |
| IL (1) | IL52462A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1983002905A1 (en) * | 1982-02-26 | 1983-09-01 | Michel Serge Maxime Lefebvre | Immobilised inorganic diffusion barriers and their application to the separation of small molecular species from a solution |
| EP1066656A1 (en) * | 1998-02-24 | 2001-01-10 | Tel-Aviv University Future Technology Development L.P. | Ion conductive matrixes and their use |
-
1977
- 1977-07-05 IL IL52462A patent/IL52462A/en unknown
-
1978
- 1978-05-23 GB GB21681/78A patent/GB1581194A/en not_active Expired
- 1978-06-05 FR FR7816782A patent/FR2408376A1/en active Granted
- 1978-06-12 DE DE19782825699 patent/DE2825699A1/en not_active Withdrawn
- 1978-06-29 JP JP7924278A patent/JPS5414377A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1983002905A1 (en) * | 1982-02-26 | 1983-09-01 | Michel Serge Maxime Lefebvre | Immobilised inorganic diffusion barriers and their application to the separation of small molecular species from a solution |
| US4717425A (en) * | 1982-02-26 | 1988-01-05 | Limitinstant Limited | Immobilized inorganic diffusion barriers and the use thereof in the separation of small molecular species from a solution |
| EP1066656A1 (en) * | 1998-02-24 | 2001-01-10 | Tel-Aviv University Future Technology Development L.P. | Ion conductive matrixes and their use |
| EP1066656A4 (en) * | 1998-02-24 | 2001-05-30 | Univ Ramot | Ion conductive matrixes and their use |
| US6811911B1 (en) | 1998-02-24 | 2004-11-02 | Tel Aviv University Future Technology Development L.P. | Ion conductive matrixes and their use |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2408376B3 (en) | 1981-02-27 |
| DE2825699A1 (en) | 1979-01-18 |
| IL52462A (en) | 1979-11-30 |
| JPS5414377A (en) | 1979-02-02 |
| FR2408376A1 (en) | 1979-06-08 |
| IL52462A0 (en) | 1977-10-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2716879B2 (en) | Composite polytetrafluoroethylene articles with controlled porosity and control methods therefor | |
| Schacher et al. | Self‐supporting, double stimuli‐responsive porous membranes from polystyrene‐block‐poly (N, N‐dimethylaminoethyl methacrylate) diblock copolymers | |
| JP3416131B2 (en) | Superporous and microporous membranes and their preparation | |
| US4188418A (en) | Separation process | |
| EP0355188B1 (en) | Process of making and using polyamide membranes useful for water softening | |
| US3556992A (en) | Anisotropic ultrafiltration membrane having adhering coating and methods of forming and using this membrane | |
| US5770631A (en) | Production process of connected microgel particles and articles treated with connected microgel particles | |
| RU2007137124A (en) | NANOCOMPOSITE MEMBRANES AND METHODS FOR PRODUCING AND USING THEM | |
| JPH0223214B2 (en) | ||
| JPS62267340A (en) | Polyvinylidene difluoride structure and its production | |
| Kotp | Enhancement of industrial effluents quality by using nanocomposite Mg/Al LDH ultrafiltration membranes | |
| Belfort et al. | Artificial particulate fouling of hyperfiltration membranes—II analysis and protection from fouling | |
| Castro et al. | The permeability behavior of polyvinylpyrrolidone-modified porous silica membranes | |
| AU610547B2 (en) | Alkali resistant hyperfiltration membrane | |
| US4338194A (en) | Method of producing solute-rejecting dynamic membrane filters and filters including such membranes | |
| US20240226817A1 (en) | Graphene membrane and method for making graphene membrane | |
| CN116036896A (en) | Composite nanofiltration membrane with low molecular weight cutoff and narrow pore size distribution and preparation method thereof | |
| GB1581194A (en) | Method of producing solute-rejecting dynamic membrane filters and filters including such membranes | |
| US3577339A (en) | Filtration method of separating liquids from extraneous materials | |
| JP3236754B2 (en) | Mosaic charged membrane, manufacturing method thereof, desalination method and desalination apparatus using the same | |
| EP0037730B1 (en) | Asymmetric ultrafiltration membrane and production thereof | |
| JP3234426B2 (en) | Manufacturing method of mosaic charged film and mosaic charged film | |
| IL31867A (en) | Improved hyperfiltration process | |
| JPH0259029A (en) | Porous membrane having hydrophilic surface and preparation thereof | |
| Errede et al. | Flow rate of water through porous membranes as affected by surface modification on the low-pressure side of the membrane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |