CN110585935A - Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof - Google Patents
Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof Download PDFInfo
- Publication number
- CN110585935A CN110585935A CN201910887130.4A CN201910887130A CN110585935A CN 110585935 A CN110585935 A CN 110585935A CN 201910887130 A CN201910887130 A CN 201910887130A CN 110585935 A CN110585935 A CN 110585935A
- Authority
- CN
- China
- Prior art keywords
- hollow fiber
- membrane
- itaconic acid
- pvdf hollow
- separation 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.)
- Granted
Links
Classifications
-
- 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
- B01D67/0081—After-treatment of organic or inorganic membranes
- B01D67/0093—Chemical modification
-
- 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
- B01D69/08—Hollow fibre membranes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/30—Polyalkenyl halides
- B01D71/32—Polyalkenyl halides containing fluorine atoms
- B01D71/34—Polyvinylidene fluoride
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/38—Graft polymerization
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/24—Mechanical properties, e.g. strength
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/36—Hydrophilic membranes
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
Abstract
The invention relates to ZrO2An itaconic acid grafted PVDF hollow fiber separation membrane, a preparation method and an application thereof, belonging to the field of polymer separation membranes. The hollow fiber separation membrane is an itaconic acid grafted PVDF hollow fiber separation membrane, and ZrO is mineralized and deposited on the surface of the hollow fiber separation membrane2. The preparation of the separation membrane comprises the following steps: (1) loading and fixing an initiator in the PVDF hollow fiber membrane; (2) preparing an itaconic acid solution, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the itaconic acid solution, and reacting to prepare an itaconic acid grafted PVDF hollow fiber membrane; (3) soaking the itaconic acid grafted PVDF hollow fiber membrane obtained in the step (2) in Zr (SO) with the PH value less than 74)2Solutions ofIn the method, biomimetic mineralization reaction is carried out to form ZrO outside the membrane2-itaconic acid microstructure. Compared with an unmodified membrane, the surface of the modified hollow fiber separation membrane is super-hydrophilic, the separation efficiency of the hollow fiber separation membrane on oil-water emulsion is excellent, and the pollution resistance is obviously enhanced. The preparation method is simple in preparation process, easy to operate and strong in universality.
Description
Technical Field
The invention belongs to the field of polymer separation membranes, and particularly relates to ZrO2An itaconic acid grafted PVDF hollow fiber separation membrane and a preparation method thereof.
Background
Compared with the traditional separation technology, the membrane separation technology has the advantages of low energy consumption, simple device, small occupied area, easy operation, high separation efficiency and the like. Among the currently commonly used polymer separation membranes, the PVDF hollow fiber membrane has the characteristics of stable chemical properties, excellent mechanical properties, good heat resistance, large packing density, low filtration pressure, easy cleaning and the like, and is widely applied to the fields of water treatment, mixed gas separation, medicine, light industry, food and the like. The inherent hydrophobic nature of the surface, however, causes two problems in the treatment of water-based fluids: firstly, the transmembrane pressure is high, and the energy consumption is high; and secondly, the membrane is easy to adsorb organic matters and the like to cause membrane pollution, so that the separation efficiency is reduced, and the service life of the membrane is shortened. How to improve the separation performance and the anti-pollution capability of the membrane through functional modification is a problem which is always concerned by academia and industry, and the importance is increasingly paid to the membrane.
Among the hydrophilic modification methods of PVDF separation membranes, surface grafting modification is favored by researchers in the field of PVDF membrane preparation due to the characteristics of abundant modification methods, high modification efficiency and the like. The invention patent CN107096398A obviously improves the hydrophilicity and the anti-pollution performance of the membrane surface by grafting the amphiphilic copolymer P (AMPS-co-MMA) on the PVDF membrane surface. In the invention patent CN103736407B, the surface of the PVDF membrane is subjected to grafting modification by maleic anhydride, a hydrophilic layer is formed on the surface of the modified membrane, and the water flux of the modified membrane is improved by more than 50%. According to the invention patent CN108404684A, firstly, hyperbranched polyethyleneimine is introduced to the surface of a PVDF membrane, and then hydroxyl with negative charge is introduced to the tail end of the PVDF membrane through a ring opening reaction, so that the hydrophilicity and the stain resistance of the membrane surface are improved. According to the invention patent CN109499393A, after a PVDF membrane is subjected to plasma treatment and acid treatment modification, firstly, aminated modified nanoparticles are grafted on the surface of the membrane, and then a polyamino polymer is fixed on the surface of the PVDF membrane through a chemical grafting method, so that the super-hydrophilic PVDF oil-water separation membrane is obtained. However, the above modification method has the following disadvantages: firstly, the influence of the steric hindrance effect causes the low coverage rate of the modified layer on the membrane surface, and the introduced hydrophilic groups are few, so that the improvement of the anti-pollution performance is limited; secondly, the modification method is complex and harsh in conditions, and the requirements of commercial production are difficult to meet.
Disclosure of Invention
The invention aims to solve the technical problem of finding a simple and universal PVDF separation membrane capable of effectively improving the surface hydrophilicity and the anti-pollution performance of the membrane and a preparation method thereof.
The invention aims to solve the problems, and the method adopts itaconic acid to graft and modify a PVDF hollow fiber membrane, and then uses carboxyl and Zr+Realizes the enrichment of metal ions on the surface of the membrane by the coordination between the Zr and the Zr+The hydrolysis reaction of (2) forms ZrO on the surface of the modified film2The bionic mineralized microstructure endows a great amount of hydroxyl groups and a special microstructure on the surface of the membrane, so that the hydrophilicity, the separation performance and the pollution resistance of the separation membrane are improved. The preparation method is simple in preparation process, and the super-hydrophilic and stable ZrO is constructed on the surface of the itaconic acid grafted PVDF hollow fiber membrane2The modified membrane has excellent permeability, interception performance and pollution resistance, and has a better separation effect when being applied to water treatment so as to overcome the defects of the prior art.
Specifically, the invention provides the following technical scheme:
the invention provides a hollow fiber separation membrane, which is characterized in that the membrane is an itaconic acid grafted PVDF hollow fiber separation membrane, and ZrO is mineralized and deposited on the surface of the membrane2。
Preferably, the hollow fiber separation membrane, wherein the PVDF hollow fiber membrane has a pore size distribution of 0.05 to 0.6 μm and a weight average molecular weight in the range of 70 to 85 ten thousand.
Preferably, the hollow fiber separation membrane, wherein the grafting density of itaconic acid on the surface of the PVDF hollow fiber membrane is: 0.15-1.2mg/cm2Preferably 0.15 to 1.02mg/cm2；
Preferably ZrO2The density of the PVDF hollow fiber membrane deposited on the surface is 0.1-1.5mg/cm2More preferably 0.23 to 1.33mg/cm2。
The present invention also provides a method for preparing the hollow fiber separation membrane described in any one of the above, characterized by comprising the steps of:
(1) loading and fixing an initiator in the PVDF hollow fiber membrane;
(2) preparing an itaconic acid solution, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the itaconic acid solution, and reacting to prepare an itaconic acid grafted PVDF hollow fiber membrane;
(3) soaking the itaconic acid grafted PVDF hollow fiber membrane obtained in the step (2) in Zr (SO) with the PH value less than 74)2In the solution, the biomimetic mineralization reaction is carried out to form ZrO outside the membrane2-itaconic acid mineralized microstructure.
Preferably, in the preparation method, the initiator in the step (1) is one of benzoyl peroxide and dicumyl peroxide, and the loading density is preferably 0.1-0.5mg/cm2More preferably 0.15 to 0.48mg/cm2。
Preferably, in the preparation method, the itaconic acid solution concentration in the step (2) is 3-10 wt%; preferably, the solution is prepared by using one solvent of deionized water, ethanol and acetone.
Preferably, in the preparation method, the grafting reaction temperature in step (2) is 60 to 80 ℃, preferably 65 to 75 ℃.
Preferably, in the preparation method, the Zr (SO) with the pH value of less than 7 is prepared in the step (3)4)2Deionized water and acid are adopted as the solution, wherein the acid is one, two or three of hydrochloric acid, sulfuric acid and nitric acid, and hydrochloric acid is preferred.
Preferably, in the preparation method, the reaction temperature in the step (3) is 40 to 90 ℃, preferably 60 to 80 ℃.
The present invention provides a hollow fiber separation membrane obtained by the production method of any one of the above.
The invention also provides the application of the hollow fiber separation membrane described in any one of the above or obtained by any one of the above preparation methods in water treatment or environmental pollution treatment.
The beneficial effects of the invention include:
1. by utilizing a surface grafting technology, itaconic acid is grafted on the surface of the PVDF hollow fiber membrane, a reactive group carboxyl is introduced, the hydrophilicity of the membrane surface is improved to a certain extent, and more hydrophilic groups can be introduced on the membrane surface because the itaconic acid molecules contain two carboxyl groups;
2. ZrO is constructed on the surface of the itaconic acid grafted PVDF hollow fiber membrane by a biomimetic mineralization technology2The mineralized microstructure further improves the hydrophilicity of the membrane surface and enhances the stability;
3. the preparation method has the advantages of simple and convenient process, easy operation, mild conditions and strong universality.
Drawings
FIG. 1 shows XPS analysis before and after modification of PVDF hollow fiber separation membranes: (M0) original unmodified PVDF hollow fiber separation membrane; (M1) itaconic acid grafted PVDF hollow fiber separation membrane of example 5; (M2) ZrO in example 52-itaconic acid grafted PVDF hollow fiber separation membrane.
FIG. 2-a is a surface topography of an original unmodified PVDF hollow fiber separation membrane;
FIG. 2 b is a surface morphology structure of the itaconic acid grafted PVDF hollow fiber separation membrane of example 5;
FIG. 2-c shows ZrO in example 52-surface morphology structure of hollow fiber micro-separation membrane of itaconic acid grafted PVDF.
Detailed Description
The present inventors have found that active functional groups such as double bonds and carboxyl groups in the molecular structure of itaconic acid can be subjected to various chemical reactions such as addition, esterification, and polymerization in order to improve the hydrophilicity, anti-contamination performance, and the like of PVDF. Through sharp research, the performance of the PVDF membrane can be improved by grafting the PVDF membrane with the itaconic acid, so that the PVDF fiber membrane grafted by the itaconic acid is designed and researched for the first time, andfurther forming ZrO on the surface of the PVDF film by utilizing biomimetic mineralization technology2The mineralized layer can endow the membrane surface with super-strong hydrophilicity on one hand, and can construct a microstructure on the membrane surface on the other hand, so that the modified membrane has more excellent oil-water separation effect and anti-pollution performance, and the hollow fiber separation membrane provided by the invention has excellent hydrophilicity, permeability, interception performance and anti-pollution performance.
Specifically, the invention provides the following technical scheme:
a hollow fiber separation membrane is characterized in that the hollow fiber separation membrane formed by grafting PVDF with itaconic acid has ZrO on the surface2And (4) mineralization and deposition.
In addition, the invention also provides a method for preparing the hollow fiber separation membrane, and the technical scheme is as follows:
a method for preparing a hollow fiber separation membrane is characterized by comprising the following steps:
(1) loading and fixing an initiator in the PVDF hollow fiber membrane;
(2) preparing an itaconic acid solution, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the itaconic acid solution, and reacting to prepare an itaconic acid grafted PVDF hollow fiber membrane;
(3) soaking the itaconic acid grafted PVDF hollow fiber membrane obtained in the step (2) in Zr (SO) with the PH value less than 74)2In the solution, the biomimetic mineralization reaction is carried out to form ZrO outside the membrane2Biomimetic mineralized microstructure of itaconic acid.
According to the preparation method, itaconic acid is grafted on the surface of the PVDF hollow fiber membrane, and then carboxyl on the surface of the modified membrane is used for inducing zirconia to generate a biomimetic mineralization reaction, so that the hydrophilic performance, the pollution resistance and the structural stability of the membrane surface are further improved. The modified membrane has super-hydrophilic surface, excellent separation efficiency on oil-water emulsion and obviously enhanced pollution resistance. The preparation method is simple in preparation process, easy to operate and strong in universality.
The ZrO of the present invention will be specifically explained below by way of examples2A preparation method of an itaconic acid grafted PVDF hollow fiber separation membrane.
Examples
In the following examples of the invention, the original PVDF hollow fiber membranes were purchased from Miborun technologies, Inc., Guizhou, with a pore size distribution of 0.05-0.6 μm, an average pore size of 0.28 μm, and a weight average molecular weight ranging from: 70-85 ten thousand.
Example 1:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.15mg/cm2；
(2) Preparing an ethanol/deionized water solution of 3 wt% itaconic acid, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1), reacting at 65 ℃ for 1 hour, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.15mg/cm2；
(3) Preparing Zr (SO) with pH value of 5 by using hydrochloric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 60 ℃ for biomimetic mineralization reaction for 8 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 0.23mg/cm2。
Example 2:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.32mg/cm2；
(2) Preparing acetone/deionized water solution of itaconic acid with the concentration of 6 wt%, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the acetone/deionized water solution, reacting for 1.5 hours at 65 ℃, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.38mg/cm2；
(3) Preparing Zr (SO) with pH value of 5 by using hydrochloric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 60 ℃ for biomimetic mineralization reaction for 8 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 0.64mg/cm2。
Example 3:
(1) the initiator is addedThe benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing ethanol/deionized water solution of itaconic acid with the concentration of 6 wt%, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the ethanol/deionized water solution, reacting at 70 ℃ for 1.5 hours, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.46mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using hydrochloric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 60 ℃ for biomimetic mineralization reaction for 9 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 0.75mg/cm2。
Example 4:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing ethanol/deionized water solution of itaconic acid with the concentration of 6 wt%, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the ethanol/deionized water solution, reacting at 70 ℃ for 2.5 hours, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.75mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using hydrochloric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 60 ℃ for biomimetic mineralization reaction for 9 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 0.91mg/cm2。
Example 5:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing an ethanol/deionized water solution of 9 wt% itaconic acid, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1), reacting at 70 ℃ for 2.5 hours, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid is graftedThe branch density is 1.02mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using nitric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 70 ℃ for biomimetic mineralization reaction for 9 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 1.33mg/cm2。
Example 6:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing an ethanol/deionized water solution of 9 wt% itaconic acid, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1), reacting at 75 ℃ for 2.5 hours, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.95mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using nitric acid and deionized water4)2Soaking itaconic acid grafted PVDF hollow fiber membrane in the solution at 70 ℃ for biomimetic mineralization reaction for 10 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 1.12mg/cm2。
Example 7:
(1) the initiator dicumyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing an ethanol/deionized water solution of 9 wt% itaconic acid, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1), wherein the itaconic acid grafted PVDF hollow fiber membrane is prepared after the reaction is carried out for 2.5 hours at the temperature of 75 ℃, and the itaconic acid grafting density is 0.86mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using sulfuric acid and deionized water4)2Soaking the itaconic acid grafted PVDF hollow fiber membrane in the solution at 80 ℃ for biomimetic mineralization reaction for 9 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2Deposition ofThe density was 1.05mg/cm2。
Example 8:
(1) the initiator benzoyl peroxide is loaded and fixed in the PVDF hollow fiber membrane, and the loading density is 0.48mg/cm2；
(2) Preparing an ethanol/deionized water solution of 9 wt% itaconic acid, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1), reacting at 75 ℃ for 2.5 hours, and preparing the itaconic acid grafted PVDF hollow fiber membrane, wherein the itaconic acid grafting density is 0.68mg/cm2；
(3) Preparing Zr (SO) with pH value of 3 by using sulfuric acid and deionized water4)2Soaking the itaconic acid grafted PVDF hollow fiber membrane in the solution at 80 ℃ for biomimetic mineralization reaction for 10 hours to form ZrO on the surface of the membrane outer membrane2Of mineralized microstructure of (1), wherein ZrO2The deposition density was 0.87mg/cm2。
PVDF hollow fiber Membrane grafted with intermediate product of only itaconic acid and ZrO as final product in the above examples2Itaconic acid graft density and ZrO of itaconic acid-grafted PVDF hollow fiber separation Membrane2The deposition density test method comprises the following steps:
wherein W1 represents the mass (mg) of the film after modification, W0 represents the mass (mg) of the film before modification, Am represents the external surface area (cm) of the PVDF film2)。
The itaconic acid graft density of the intermediate product prepared in step (2) and ZrO of the final product prepared in step (3) in each of the above examples are summarized2Deposition density, as shown in the following table:
TABLE 1 examples 1-8 itaconic acid graft Density with ZrO2Density of deposition
| Examples | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| Itaconic acid graft Density (mg/cm)2) | 0.15 | 0.38 | 0.46 | 0.75 | 1.02 | 0.95 | 0.86 | 0.68 |
| ZrO2Deposition Density (mg/cm)2) | 0.23 | 0.64 | 0.75 | 0.91 | 1.33 | 1.12 | 1.05 | 0.87 |
Characterization test results for the hollow fiber membranes prepared in examples 1-8 above:
(1) testing the average pore diameter of the separation membrane according to a maximum bubble point method, and adopting a 3H-2000PB type full-automatic bubble pressure method filter membrane pore diameter analyzer of Behcet instruments and technologies (Beijing) Limited company to test the pressure to be 0.3 MPa;
(2) and (3) measuring the porosity of the separation membrane by adopting a weighing method, wherein the reagent used for adsorption is n-butyl alcohol:
wherein, ε%: porosity; mpAnd ρp: the mass and density of the dry film, wherein the dry film density is: dry film mass/dry film volume; mbAnd ρbRespectively as follows: the mass and density of n-butanol adsorbed by the separation membrane.
(3) XPS detection result analysis of the hollow fiber membrane prepared by the invention
For the original unmodified PVDF hollow fiber membrane and the itaconic acid-only grafted PVDF hollow fiber membrane prepared in the step (2) of the above example 5 and ZrO prepared in the step (3)2Itaconic acid grafted PVDF hollow fiber separation membranes, respectively subjected to XPS test, with the test instruments being PHI-1600, Perkin-Elmer Co., USA.
FIG. 1 shows the XPS test results, and it can be seen from FIG. 1 that M0 is the XPS curve of the original PVDF hollow fiber membrane, which shows characteristic peaks of C1s, O1s and F1 s; m1 is an XPS curve of the PVDF fiber membrane grafted and modified by itaconic acid, and the curve shows that the characteristic peak of new elements does not appear on the XPS curve because itaconic acid molecules only contain C, 0 and H elements; and in the M2 curve, ZrO passes2The deposited PVDF fiber film has new characteristic peaks of Zr element in an XPS graph, so the XPS result shows that the experimental scheme of the invention is determined to be feasible. Wherein XPS analysis before and after modification (M0: unmodified PVDF hollow fiber separation membrane; M1: itaconic acid-grafted PVDF hollow fiber separation membrane of example 5; M2: ZrO of example 5)2-itaconic acid grafted PVDF hollow fiber separationFilm)
(4) SEM analysis of surface appearance of hollow fiber membrane prepared by the invention
Surface morphology: the surface morphology of the film was observed by a QuantaFEG 250 type field emission scanning electron microscope (FEI, USA), and the sample was treated by spraying gold (scale: 5 μm, magnification: 20k) before the test. Wherein, FIG. 2-a is SEM photograph of original PVDF hollow fiber membrane, FIG. 2-b is PVDF fiber membrane grafted with itaconic acid, and the comparison shows that the pore diameter of the membrane is reduced after grafting with hydrophilic molecule itaconic acid; FIG. 2-c is ZrO2SEM photograph of hollow fiber separation membrane of itaconic acid-grafted PVDF, comparing with (b), it can be seen that the pore diameter of the fiber membrane does not change much and the membrane surface becomes uneven, indicating that ZrO exists on the surface2Deposition occurs and mineralized deposition does not cause damage to the pore structure of the membrane, wherein both fig. 2-b and fig. 2-c employ the separation membrane prepared in example 5.
(5) ZrO prepared by the invention2The surface wetting property, pure water flux, separation property and contamination resistance property test conditions and procedures of the itaconic acid-grafted PVDF hollow fiber separation membrane and the intermediate product prepared in the step (2) of the above example, i.e., the itaconic acid-only-grafted PVDF membrane, are as follows:
surface wettability the water contact angle of the membrane surface was measured using a model DSA25S contact angle tester, produced by KRUSS, germany, at 5 different locations on each sample, respectively, at room temperature, and the average was then determined.
The water flux, separation performance and anti-pollution performance of the separation membrane are as follows: the water flux, separation and pollution resistance of the membrane are measured by an external pressure method (the prepressing pressure is 0.15MPa at room temperature, the prepressing time is 0.5h, the pore structure can be stable through the prepressing process, the great attenuation of the permeation flux is avoided, and the test pressure is 0.1MPa at room temperature).
Firstly testing the pure water permeability of the separation membrane, recording the volume of the permeated water of different separation membranes, the effective membrane area and the permeation time, and calculating the pure water flux J according to the formula (1)w1；
Then, an oil-water emulsion (vacuum pump oil: sodium dodecyl sulfate: deionized water ═ 0.9:0.1: 999: (vacuum pump oil))Mass ratio)) as a feed liquid, the oil-water concentration is CfAfter filtering for 6 hours, the obtained oil-water concentration is CpAnd then calculating oil-water separation efficiency R (%) according to a formula (2), wherein the vacuum pump oil: the trade mark is as follows: GS-1, manufacturer: beijing Beihua Wanda science and technology, Inc.;
then, after the separation membrane is cleaned (clear water and ultrasonic cleaning for half an hour) for three times, pure water is used as a feeding liquid again, and the water flux J of the cleaned separation membrane is recorded and calculated according to the formula (1) to obtain the water flux J of the separation membranew2And finally calculating the water Flux Recovery Rate (FRR) by adopting a formula (3).
The calculation formula of the above test is as follows:
in the formula, J-water flux, L/m2h; v-volume of permeated water, L; a-effective membrane area, m2(ii) a Δ t-penetration time, h.
In the formula, R-oil-water separation efficiency,%; cf-pre-filtration oil water concentration, mg/L; cp-oil water concentration after filtration, mg/L. (the concentration is equal to the mass of oil/volume of oil-water mixture, and the measurement is carried out by ultraviolet spectrophotometer by first drawing a standard curve of concentration and absorbance, and determining the concentration according to the standard curve after measuring the absorbance during the measurement)
FRR Water flux recovery (%), JW2Represents the water flux of the membrane after washing with clear water, JW1Indicating the initial water flux of the membrane.
Through the above tests, the intermediate products prepared in step (2) of examples 1 to 8 were prepared by grafting only itaconic acid to PVDF hollow fiber membrane and ZrO as the final product prepared in step (3)2Grafting of itaconic acid to PVDFThe porosity, water contact angle, pure water flux, oil-water separation efficiency and water flux recovery of the hollow fiber separation membrane are summarized in tables 2 and 3:
TABLE 2 Performance of intermediate itaconic acid grafted PVDF hollow fiber membranes
TABLE 3 ZrO2Performance of-itaconic acid grafted PVDF hollow fiber separation Membrane
As can be seen from the above test data, compared with the performance of the original PVDF hollow fiber membrane, the performance of the modified PVDF hollow fiber membrane (including the intermediate product and the final product) is improved in the invention, because the itaconic acid molecules and ZrO are introduced to the surface of the original PVDF hollow fiber membrane by the modification means2The hydrophilicity of the fiber membrane can be improved by deposition, so that the performance of the modified PVDF fiber membrane is improved;
in addition, the properties of the intermediate products prepared in examples 1 to 8 were compared with those of the final product, in which ZrO was obtained2The water contact angle of the itaconic acid grafted PVDF hollow fiber separation membrane is 86.5-5.6 degrees, and the pure water flux is 233.6-776.5 (L/m)2h) The oil-water separation efficiency is 65.1-99.9%, the water flux recovery rate is 63.2-98.7%, and compared with the porosity of the original PVDF hollow fiber membrane, the porosity of the modified PVDF fiber membrane is not changed greatly, so that the modification process of the invention is proved not to damage the surface structure characteristic porosity of the PVDF fiber membrane;
furthermore, as can be seen from the above table, the intermediate products prepared in examples 5 and 6 have the best performance with respect to the final product, the water contact angle of the final product is 5-10 °, and the pure water flux is 650-780L/m2h, the oil-water separation efficiency is 96-99.9%, and the water flux recovery rate is 95-99%. The reasons for the superior performance of the two embodiments described above are: when the itaconic acid grafting is carried out in the step (2), the method adoptsBenzoyl peroxide initiator, itaconic acid solution concentration 9 wt%; when the mineralization deposition is carried out in the step (3), the mineralization is carried out in a nitric acid solution, and the temperature of the mineralization is 70 ℃. The PVDF fiber membrane obtained by the method has good hydrophilicity and anti-fouling performance.
The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the scope of the invention, and all equivalent changes and modifications made within the spirit and scope of the present invention should be included in the present invention.
Claims (10)
1. A hollow fiber separation membrane is characterized in that the membrane is an itaconic acid grafted PVDF hollow fiber separation membrane, and ZrO is mineralized and deposited on the surface of the membrane2。
2. The hollow fiber separation membrane according to claim 1, wherein the PVDF hollow fiber membrane has a pore size distribution of 0.05 to 0.6 μm and a weight average molecular weight in the range of 70 to 85 ten thousand.
3. The hollow fiber separation membrane according to claim 1 or 2, wherein the grafting density of itaconic acid on the surface of the PVDF hollow fiber membrane is: 0.15-1.2mg/cm2Preferably 0.15 to 1.02mg/cm2；
Preferably ZrO2The density of the PVDF hollow fiber membrane deposited on the surface is 0.1-1.5mg/cm2More preferably 0.23 to 1.33mg/cm2。
4. A method for preparing a hollow fiber separation membrane according to any one of claims 1 to 3, comprising the steps of:
(1) loading and fixing an initiator in the PVDF hollow fiber membrane;
(2) preparing an itaconic acid solution, soaking the PVDF hollow fiber membrane loaded with the initiator in the step (1) in the itaconic acid solution, and reacting to prepare an itaconic acid grafted PVDF hollow fiber membrane;
(3) soaking the itaconic acid grafted PVDF hollow fiber membrane obtained in the step (2) in Zr (SO) with the PH value less than 74)2In solution, intoCarrying out biomimetic mineralization reaction to form ZrO outside the membrane2-itaconic acid mineralized microstructure.
5. The preparation method according to claim 4, wherein the initiator in the step (1) is one of benzoyl peroxide and dicumyl peroxide, and the loading density is preferably 0.1-0.5mg/cm2More preferably 0.15 to 0.48mg/cm2。
6. The production method according to claim 4 or 5, wherein the itaconic acid solution concentration in the step (2) is 3 to 10 wt%; preferably, the solution is prepared by using one solvent of deionized water, ethanol and acetone.
7. The production method according to any one of claims 4 to 6, wherein the grafting reaction temperature in step (2) is 60 to 80 ℃, preferably 65 to 75 ℃.
8. The production method according to any one of claims 4 to 7, wherein Zr (SO) having a pH of less than 7 is formulated in step (3)4)2Deionized water and acid are adopted as the solution, wherein the acid is one, two or three of hydrochloric acid, sulfuric acid and nitric acid, and nitric acid is preferred.
9. The production method according to any one of claims 4 to 8, wherein the mineralization reaction temperature in step (3) is 40 to 90 ℃, preferably 60 to 80 ℃, and more preferably 70 to 75 ℃.
10. Use of a hollow fibre separation membrane according to any one of claims 1 to 3 or prepared by a process according to any one of claims 4 to 9 in water treatment or environmental pollution remediation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910887130.4A CN110585935B (en) | 2019-09-19 | 2019-09-19 | Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910887130.4A CN110585935B (en) | 2019-09-19 | 2019-09-19 | Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110585935A true CN110585935A (en) | 2019-12-20 |
| CN110585935B CN110585935B (en) | 2021-11-30 |
Family
ID=68861139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910887130.4A Active CN110585935B (en) | 2019-09-19 | 2019-09-19 | Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110585935B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111330454A (en) * | 2020-03-12 | 2020-06-26 | 燕山大学 | Amyloid fiber nano-zirconia composite membrane for efficiently and deeply purifying fluoride ions in water and preparation and purification method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030020475A (en) * | 2001-08-29 | 2003-03-10 | 백동수 | Process for preparing of a proton-conducting polyvinylidene fluoride membrane |
| CN1509804A (en) * | 2002-12-26 | 2004-07-07 | 天津工业大学膜科学与技术研究所 | Method for preparing composite hollow fibre membrane |
| CN107088367A (en) * | 2016-11-18 | 2017-08-25 | 曲靖师范学院 | A kind of preparation method of anti-pollution PVDF hybridized film |
| CN107126849A (en) * | 2017-06-22 | 2017-09-05 | 曲靖师范学院 | A kind of preparation method of hydrophilic polyvinylidene fluoride hybridized film |
| CN108722201A (en) * | 2018-06-11 | 2018-11-02 | 贵州省材料产业技术研究院 | The method of modifying of PVDF hollow-fibre membranes |
| CN109065926A (en) * | 2018-08-06 | 2018-12-21 | 西北工业大学 | Mineralising legal system in situ has machine-Inorganic multilayer compound proton exchange membrane preparation method |
-
2019
- 2019-09-19 CN CN201910887130.4A patent/CN110585935B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20030020475A (en) * | 2001-08-29 | 2003-03-10 | 백동수 | Process for preparing of a proton-conducting polyvinylidene fluoride membrane |
| CN1509804A (en) * | 2002-12-26 | 2004-07-07 | 天津工业大学膜科学与技术研究所 | Method for preparing composite hollow fibre membrane |
| CN107088367A (en) * | 2016-11-18 | 2017-08-25 | 曲靖师范学院 | A kind of preparation method of anti-pollution PVDF hybridized film |
| CN107126849A (en) * | 2017-06-22 | 2017-09-05 | 曲靖师范学院 | A kind of preparation method of hydrophilic polyvinylidene fluoride hybridized film |
| CN108722201A (en) * | 2018-06-11 | 2018-11-02 | 贵州省材料产业技术研究院 | The method of modifying of PVDF hollow-fibre membranes |
| CN109065926A (en) * | 2018-08-06 | 2018-12-21 | 西北工业大学 | Mineralising legal system in situ has machine-Inorganic multilayer compound proton exchange membrane preparation method |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111330454A (en) * | 2020-03-12 | 2020-06-26 | 燕山大学 | Amyloid fiber nano-zirconia composite membrane for efficiently and deeply purifying fluoride ions in water and preparation and purification method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110585935B (en) | 2021-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhu et al. | Improving the hydrophilic and antifouling properties of polyvinylidene fluoride membrane by incorporation of novel nanohybrid GO@ SiO2 particles | |
| Gao et al. | Regenerated cellulose strongly adhered by a supramolecular adhesive onto the PVDF membrane for a highly efficient oil/water separation | |
| Yu et al. | Improving the antifouling property of polyethersulfone ultrafiltration membrane by incorporation of dextran grafted halloysite nanotubes | |
| Xu et al. | Organosilane-functionalized graphene oxide for enhanced antifouling and mechanical properties of polyvinylidene fluoride ultrafiltration membranes | |
| Ray et al. | Surface engineering for anti-wetting and antibacterial membrane for enhanced and fouling resistant membrane distillation performance | |
| Zhang et al. | Engineering amphiphilic nanofiltration membrane surfaces with a multi-defense mechanism for improved antifouling performances | |
| Ma et al. | Functional surface modification of PVDF membrane for chemical pulse cleaning | |
| Zhou et al. | Cellulose acetate ultrafiltration membranes reinforced by cellulose nanocrystals: Preparation and characterization | |
| He et al. | A nonionic polymer-brush-grafted PVDF membrane to analyse fouling during the filtration of oil/water emulsions | |
| CN104001436A (en) | Method for preparing amidogen-modified oxidized graphene grafting modification ultra-filtration or micro-filtration membrane | |
| CN111286068B (en) | Method for preparing hydrophilic-hydrophobic composite membrane by grafting zwitterion on surface | |
| Yu et al. | Effect of functionalized multi-walled carbon nanotubes on the microstructure and performances of PVDF membranes | |
| CN107899432B (en) | A kind of plate compounding nanofiltration membrane and preparation method thereof for water filter purification | |
| Wang et al. | Surface modification of mesoporous silica nanoparticle with 4-triethoxysilylaniline to enhance seawater desalination properties of thin-film nanocomposite reverse osmosis membranes | |
| CN110585935B (en) | Zirconium dioxide-itaconic acid grafted PVDF hollow fiber separation membrane and preparation method and application thereof | |
| CN110548478A (en) | modified magnetic nano particle and application thereof | |
| Ahmad et al. | Optimization of a high performance 3-aminopropyltriethoxysilane-silica impregnated polyethersulfone membrane using response surface methodology for ultrafiltration of synthetic oil-water emulsion | |
| Li et al. | PVA and CS cross-linking combined with in situ chimeric SiO 2 nanoparticle adhesion to enhance the hydrophilicity and antibacterial properties of PTFE flat membranes | |
| Zhu et al. | Preparation of organic–inorganic hybrid membranes with superior antifouling property by incorporating polymer-modified multiwall carbon nanotubes | |
| Wang et al. | Chemically graft aminated GO onto dehydro-fluorinated PVDF for preparation of homogenous DF-PVDF/GO-NH2 ultrafiltration membrane with high permeability and antifouling performance | |
| CN115772348A (en) | Full-bio-based super-hydrophilic/underwater super-oleophobic coating and preparation method thereof | |
| Guo et al. | Interpenetrating network nanoarchitectonics of antifouling poly (vinylidene fluoride) membranes for oil–water separation | |
| Guo et al. | Silica-modified electrospun membrane with underwater superoleophobicity for effective gravity-driven oil/water separation | |
| CN113522038A (en) | Preparation method and application of composite membrane for removing pollutants in water | |
| CN110270236B (en) | Preparation method and application of oil-proof swelling-resistant oil-water separation membrane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |