CN110773000B - Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof - Google Patents
Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof Download PDFInfo
- Publication number
- CN110773000B CN110773000B CN201911089492.5A CN201911089492A CN110773000B CN 110773000 B CN110773000 B CN 110773000B CN 201911089492 A CN201911089492 A CN 201911089492A CN 110773000 B CN110773000 B CN 110773000B
- Authority
- CN
- China
- Prior art keywords
- graphene oxide
- carboxylated graphene
- nanofiltration membrane
- carboxylated
- dispersion liquid
- 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.)
- Active
Links
Images
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
- B01D67/0079—Manufacture of membranes comprising organic and inorganic components
-
- 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
- B01D69/10—Supported membranes; Membrane supports
-
- 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
- B01D71/02—Inorganic material
- B01D71/021—Carbon
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
The embodiment of the application provides a preparation method of a high-efficiency and anti-pollution carboxylated graphene oxide nanofiltration membrane, which comprises the following steps: s1: preparing graphene oxide into a graphene oxide dispersion liquid by using pure water; s2: adding HBr into the graphene oxide dispersion liquid, and stirring and reacting for 10-15 h; s3: after the reaction of the step S2, adding oxalic acid into the reaction system, continuously stirring and reacting for 2-6 h, and taking a reaction product; s4: carrying out centrifugal purification on the reaction product obtained in the step S3 to obtain carboxylated graphene oxide; s5: and (4) preparing the carboxylated graphene oxide obtained in the step (S4) into a carboxylated graphene oxide dispersion liquid, and performing suction filtration on the carboxylated graphene oxide dispersion liquid on a polyvinylidene fluoride support membrane to obtain the carboxylated graphene oxide nanofiltration membrane. The method for preparing the carboxylated graphene oxide nanofiltration membrane is simple, easy to operate, free of more chemical reagents, more environment-friendly, cost-saving, and strong in organic wastewater treatment capacity and anti-fouling capacity.
Description
Technical Field
The application relates to the technical field of nanofiltration membranes, in particular to a high-efficiency and anti-pollution carboxylated graphene oxide nanofiltration membrane, a preparation method and application thereof.
Background
In the water treatment separation membrane, a nanofiltration membrane is used as a new membrane technology, the separation efficiency of the nanofiltration membrane is higher than that of an ultrafiltration membrane, organic micromolecules and multivalent salts can be effectively intercepted, and purified water can meet most purposes, such as: food, medical treatment, scientific research, pharmacy and the like. In addition, on the premise that the filtration effect is close to that of the reverse osmosis technology, the applied pressure required by the reverse osmosis membrane technology is much smaller than that of the reverse osmosis membrane technology, so that the nanofiltration membrane technology attracts attention as a membrane separation technology with high efficiency and low energy consumption.
In the practical application of the nanofiltration membrane, the traditional polymeric nanofiltration membrane is limited due to the low water treatment efficiency, the complex process and the environmental protection of raw materials. Compared with the traditional nanofiltration membrane material, the graphene oxide nanofiltration membrane becomes a natural nanofiltration membrane material due to the strong mechanical stability and controllable interlayer spacing of the graphene oxide nanofiltration membrane. In recent years, the research report of the graphene oxide nanofiltration membrane is frequent, and the prior art well solves the problem of low water flux of the traditional nanofiltration membrane technology. However, under the condition of an applied pressure, the graphene oxide nanofiltration membrane has two major challenges in treating organic wastewater, namely: high water treatment efficiency and long-term stability.
Disclosure of Invention
An object of the embodiment of the application is to provide a preparation method of a high-efficiency anti-pollution carboxylated graphene oxide nanofiltration membrane, so as to achieve the technical effects of improving the anti-pollution performance of the nanofiltration membrane, treating the organic wastewater and prolonging the service life of the membrane.
The application is realized by the following technical scheme:
the method comprises the following steps:
s1: preparing graphene oxide into a graphene oxide dispersion liquid by using pure water;
s2: adding HBr into the graphene oxide dispersion liquid, and stirring and reacting for 10-15 h;
s3: after the reaction of the step S2, adding oxalic acid into the reaction system, continuously stirring and reacting for 2-6 h, and taking a reaction product;
s4: carrying out centrifugal purification on the reaction product obtained in the step S3 to obtain carboxylated graphene oxide;
s5: and (4) preparing the carboxylated graphene oxide obtained in the step (S4) into a carboxylated graphene oxide dispersion liquid, and performing suction filtration on the carboxylated graphene oxide dispersion liquid on a polyvinylidene fluoride support membrane to obtain the carboxylated graphene oxide nanofiltration membrane.
In order to better implement the present application, further, the specific operation of centrifugal purification in S4 is as follows:
s41, centrifuging the reaction product obtained in the step S3 at 10000 rpm, taking the precipitate, and cleaning the precipitate by pure water;
s42, centrifuging the sediment cleaned in the step S41 at 10000 r/min, taking the sediment, and cleaning the sediment by pure water;
and S43, centrifuging the precipitate cleaned in the step S42 at 10000 rpm, taking the precipitate, and cleaning the precipitate with pure water to obtain the carboxylated graphene oxide. .
To better implement the present application, further, the S5: and preparing the carboxylated graphene oxide obtained in the step S4 into a carboxylated graphene oxide dispersion liquid, wherein the concentration of the carboxylated graphene oxide dispersion liquid is 0.05 mg/mL.
In order to better implement the present application, the carboxylated graphene oxide dispersion in S5 further includes diluting the carboxylated graphene oxide dispersion with pure water, stirring, and performing ultrasonic dispersion before suction filtration.
In order to better implement the present application, further, in the step S3, oxalic acid is added into the reaction system, and the reaction is continued to be stirred for 4 hours, and the reaction product is taken out.
In order to better implement the present application, in step S2, HBr is added to the graphene oxide dispersion, and the mixture is stirred at 1000 rpm at normal temperature for 12 hours. .
In order to better realize the application, further, the monolayer size of the graphene oxide in the step S1 is less than or equal to 15 μm.
The second purpose of the embodiment of the application is to provide a high-efficient, anti-soil carboxylation oxidation graphite alkene nanofiltration membrane.
The third purpose of the embodiment of the application is to provide an application of the efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane in organic wastewater treatment.
The action mechanism is as follows: the invention provides a high-efficiency anti-fouling carboxylated graphene oxide nanofiltration membrane, HBr and oxalic acid are added into a graphene oxide dispersion liquid for biochemical reaction to obtain carboxylated graphene oxide, after carboxylation, a large number of negative charge carboxyl groups are arranged on the surface of the membrane, electrostatic repulsion is increased, and the inter-lamellar spacing of the nanofiltration membrane is further increased, so that the water flux is increased, the filtration efficiency is improved, and the working efficiency is further improved in the subsequent use process; the removal rate of the carboxylated nanofiltration membrane can reach more than 99.10 percent in the organic wastewater treatment process by taking a Trimeryl blue solution as an example, and compared with the existing graphene oxide nanofiltration membrane, the prepared carboxylated graphene oxide has better anti-fouling and easy-cleaning performances, mainly because the electrostatic action formed after carboxylation has the effect of repelling anionic dye, the service life of the membrane is prolonged, and the removal rate of the dye is increased.
Through carrying out cycle test to the blue solution of tritolyl blue with the carboxylation oxidation graphite alkene nanofiltration membrane that this application provided, though there is certain decline in throughput after the circulation many times, remain throughout more than 92%, further prove that carboxylation oxidation graphite alkene nanofiltration membrane antipollution ability is stronger, and is more durable, and economic benefits is higher.
In the process of preparing the carboxylated graphene oxide nanofiltration membrane, the size of a single layer of graphene oxide is preferably less than or equal to 15 microns, because the smaller the size, the more favorable the subsequent dispersion and the more favorable the subsequent carboxylation reaction.
In order to enhance the effect of dispersion centrifugation, it is preferable that the reaction product obtained in step S4 is centrifuged and purified three times to obtain carboxylated graphene oxide having a smaller size.
When the carboxylated graphene oxide dispersion liquid is prepared, no precipitation occurs in the subsequent film making process, so that the concentration of the carboxylated graphene oxide dispersion liquid is further limited to be 0.05mg/mL, and the carboxylated graphene oxide dispersion liquid is diluted before suction filtration, so that the film making effect is ensured.
The beneficial effects of the embodiment of the application are that:
(1) the method for preparing the carboxylated graphene oxide nanofiltration membrane is simple, easy to operate, free of more chemical reagents, more environment-friendly and cost-saving; meanwhile, the prepared nanofiltration membrane has a large number of negatively charged carboxyl groups, and the lamella spacing is increased under the action of electrostatic repulsion, so that the water flux is increased, the filtration speed is increased, and the service life of the nanofiltration membrane is prolonged and the removal rate of dye is increased because the electrostatic interaction has the effects of resisting and repelling anionic dye.
(2) According to the invention, a method of modifying the surface functional groups of the graphene oxide by oxalic acid is adopted, a large amount of charges are enriched, and the hydrophilicity and the electrostatic repulsion of the membrane are enhanced while the interlayer spacing of the graphene oxide membrane is increased, so that the effects of increasing the water flux and improving the fuel repulsion are achieved; greatly prolongs the service life of the membrane and the capability of treating organic wastewater, thereby increasing the economic benefit of enterprises.
(3) The carboxylated graphene oxide prepared by the invention keeps better treatment capacity in the organic wastewater treatment process.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.
FIG. 1 is a schematic representation of the preparative carboxylation reaction of the present application;
fig. 2 is a schematic view of the preparation of the carboxylated graphene oxide nanofiltration membrane according to the present application;
FIG. 3 is a graphical representation of XPS characterization of the relative content of oxygen-containing functional groups of graphene oxide and carboxylated graphene oxide, respectively, according to the present application;
FIG. 4 is a schematic thermogravimetric analysis of graphene oxide and carboxylated graphene oxide according to the present application;
FIG. 5 is an infrared spectrum of graphene oxide and carboxylated graphene oxide of the present application;
fig. 6 is a raman spectrum of graphene oxide and carboxylated graphene oxide according to the present application;
FIG. 7 is a schematic representation of water contact angles of graphene oxide and carboxylated graphene oxide according to the present application;
FIG. 8 is a zete potential diagram of graphene oxide dispersions and carboxylated graphene oxide dispersions of the present application;
fig. 9 is an XRD spectrogram of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane both in a dry state;
fig. 10 is an XRD spectrum of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane in a wet state;
fig. 11 is an XPD spectrum of the carboxylated graphene oxide nanofiltration membrane according to the present application at different PH values;
figure 12 is an SEM image of the graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane of the present application;
figure 13 is a schematic water flux diagram of graphene oxide nanofiltration membranes and carboxylated graphene oxide nanofiltration membranes according to the present application;
fig. 14 is a schematic diagram of a curve showing the removal rate of the dye, namely, tricresyl blue, by the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane according to the present application, as a function of the volume of the filtrate;
fig. 15 is a line graph of the removal rate of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane for 5 cycles of tritolyl blue;
figure 16 is a schematic diagram of the final flux of the present disclosure after cycling of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane;
fig. 17 is a comparison graph of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane before and after surface filtration and after cleaning.
Detailed Description
The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.
Examples
High-efficiency anti-pollution carboxylated graphene oxide nanofiltration membrane
The preparation method comprises the following steps:
s1: preparing graphene oxide with the single-layer size of less than or equal to 15 microns into 2.5mg/mL graphene oxide dispersion liquid by using pure water;
s2: taking 30ml of graphene oxide dispersion liquid, adding 5ml of HBr into a beaker, and violently stirring at the rotating speed of 1000 rpm for reaction for 12 hours;
s3: after the reaction of the step S2, adding 1.5g of oxalic acid into the reaction system, continuously stirring and reacting for 4 hours, and taking a reaction product;
s4: carrying out centrifugal dispersion purification on the reaction product, and specifically operating the following steps:
s41, centrifuging the reaction product obtained in the step S3 at 10000 rpm, taking the precipitate, and cleaning the precipitate with pure water;
s42, centrifuging the sediment cleaned in the step S41 at 10000 r/min, taking the sediment, and cleaning the sediment by pure water;
s43, centrifuging the precipitate cleaned in the step S42 at 10000 r/min, taking the precipitate, cleaning the precipitate with pure water to obtain carboxylated graphene oxide, and drying the obtained carboxylated graphene oxide in vacuum at the temperature of 40 ℃;
s5: preparing the obtained carboxylated graphene oxide into 0.05mg/mL carboxylated graphene oxide dispersion liquid by pure water; diluting the carboxylated graphene oxide dispersion liquid with 50ml of pure water, stirring, ultrasonically dispersing and centrifuging to obtain a dilute carboxylated graphene oxide dispersion liquid, then carrying out suction filtration on the dilute carboxylated graphene oxide dispersion liquid on a polyvinylidene fluoride supporting membrane with the aperture of 0.05 mu m in a vacuum filtration mode under the vacuum degree of 0.085Mpa to form a carboxylated graphene oxide nanofiltration membrane, and drying the obtained carboxylated graphene oxide nanofiltration membrane for 2 hours under the vacuum condition at 40 ℃.
Comparative example
Graphene oxide nanofiltration membrane
The preparation method comprises the following steps:
s1: preparing graphene oxide with the single-layer size of less than or equal to 15 microns into 2.5mg/mL graphene oxide dispersion liquid by using pure water;
s2: diluting the graphene oxide dispersion liquid with 50ml of pure water, stirring, ultrasonically dispersing and centrifuging to obtain a dilute graphene oxide dispersion liquid, then carrying out suction filtration on the dilute graphene oxide dispersion liquid on a polyvinylidene fluoride support membrane with the aperture of 0.05 mu m in a vacuum filtration mode under the vacuum degree of 0.085Mpa to form a graphene oxide nanofiltration membrane, and drying the obtained graphene oxide nanofiltration membrane for 2 hours under the vacuum condition at 40 ℃.
Experimental testing
Specifically, the following description is provided: graphene oxide is abbreviated as GO, carboxylated graphene oxide is abbreviated as C-GO, a graphene oxide nanofiltration membrane is abbreviated as GO membrane, and a carboxylated graphene oxide nanofiltration membrane is abbreviated as C-GO membrane.
1. XPS is used for characterizing the relative content of each oxygen-containing functional group of graphene oxide and carboxylated graphene oxide
The experimental result is shown in fig. 3, wherein a represents an XPS spectrogram of graphene oxide, b represents an XPS spectrogram of carboxylated graphene oxide, the number of oxygen-containing functional groups of the carboxylated graphene oxide is reduced to a certain extent compared with the number of oxygen-containing functional groups of graphene oxide, the spectrogram performs peak separation on C1s, and compared with the relative content of different oxygen-containing functional groups, as can be seen from b in fig. 3, the area of the carboxyl group peak is significantly increased, and the area of the hydroxyl group peak is greatly reduced, at this time, it can be proved that a large amount of hydroxyl groups are successfully esterified with carboxyl groups during the carboxylation process, so as to prepare carboxylated graphene oxide with the carboxyl group content as the dominant.
2. Thermogravimetric analysis of graphene oxide and carboxylated graphene oxide
The results of the experiment are shown in FIG. 4: the thermogravimetric analysis is carried out in an oxygen environment at a heating speed of 5 ℃ per minute, wherein the weight loss of the sample is generated by the escape of free water molecules of the sample within a range of 40-100 ℃; the weight change of the sample at 100-185 ℃ is relatively stable, wherein the weight loss is mainly caused by desorption and oxidation of physically adsorbed water molecules and unstable oxygen-containing functional groups under the heating condition; after 185 ℃, the relatively stable oxygen-containing functional group is oxidized into a dioxide group and water at high temperature, so that the tested sample is obviously weightless. Comparing the weight loss curves of the graphene oxide and the carboxylated graphene oxide shows that the curve of the carboxylated graphene oxide is lower than that of the graphene oxide, because the mass fraction of the esterified functional groups is greatly improved compared with that of the hydroxyl groups after the oxalic acid and the hydroxyl groups are esterified, so that the mass fraction of the esterified functional groups is increased, the weight loss ratio of the carboxylated graphene oxide is higher than that of the graphene oxide in the thermogravimetric analysis process of the same mass of the graphene oxide and the carboxylated graphene oxide, and the successful preparation of the carboxylated graphene oxide is further verified from the side.
3. Infrared spectroscopic analysis of graphene oxide and carboxylated graphene oxide
The experimental result is shown in FIG. 5, 1729cm-1A stretching vibration peak of O in-COOH of 1399-1064 cm-1The stretching vibration peak of C-O in C-OH/C-O-C is 1479-1309 cm-1The peak is due to C-O vibration in-COOH. Comparing the infrared spectrograms of the graphene oxide and the carboxylated graphene oxide, the two tested samples both contain hydroxyl, epoxy and carbonyl, and the carboxylated graphene oxide is 1479-1309 cm-1The peak is obviously sharper than that of graphene oxide, and the carboxyl content is proved to be improved after carboxylation.
4. Raman spectroscopy analysis of graphene oxide and carboxylated graphene oxide
As shown in FIG. 6, in graphene and its derivatives, Raman spectrum is commonly used to evaluate the order and defect condition of graphene film, D peak strength represents the defect of graphene sheet and whether the arrangement of graphite sheet is disordered, G peak strength represents sp in graphite sheet2What the intrinsic C is. And the ratio thereof was used to analyze the degree of defects and disorder of the sample film. Visible graphene oxide ID/IG0.9975, I of carboxylated graphene oxideD/IG0.9955, I of carboxylated graphene oxideD/IGThe value was slightly reduced due to the slight reduction of graphene oxide during the esterification process.
5. Water contact angle experiment of graphene oxide and carboxylated graphene oxide
The experimental result is shown in fig. 7, the water contact angle of the surface of the graphene oxide nanofiltration membrane is 39.6 °, the water contact angle of the surface of the carboxylated graphene oxide nanofiltration membrane is 46.4 °, and further, the experimental result shows that a large number of carboxyl groups change the properties of the surface of the membrane after carboxylation, which means that the hydrophilicity is reduced, and further shows that the carboxylated graphene oxide is successfully prepared.
6. Zete potential analysis of graphene oxide dispersion and carboxylated graphene oxide dispersion
As shown in fig. 8, the potentials of the graphene oxide and the carboxylated graphene oxide are negative values, which is caused by the carboxyl groups with a large amount of negative charges on the surfaces, and the absolute value of the zeta potential of the carboxylated graphene oxide is larger than that of the graphene oxide, because the carboxylated graphene oxide is repelled by a large amount of negative charges on the surface of the sheet layer, and the dispersibility of the sheet layer is enhanced.
7. XRD (X-ray diffraction) pattern analysis of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane in dry state
The experimental result is shown in fig. 9, when the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane are both at about 10 degrees in 2 theta in a dry state, the difference is not large, and the interlayer distance graphene oxide nanofiltration membrane is calculated according to the bragg formula
The carboxylated graphene oxide nanofiltration membrane is
Further shows that after carboxylation, the group behind the oxalate plays a supporting role, and the distance between the sheets is increased.
8. XRD (X-ray diffraction) spectrum analysis of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane in wet state
The results of the experiment are shown in FIG. 10Under the wet state, the 2 theta values of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane are obviously different, and the interlamellar spacing of the graphene oxide nanofiltration membrane under the wet state is calculated according to the Bragg formula
The carboxylated graphene oxide nanofiltration membrane is
This is also due to the charge repulsion effect that results from the negative charge carried by the plurality of carboxyl groups.
9. XPD spectrogram analysis of carboxylated graphene oxide nanofiltration membrane under different pH values
As shown in fig. 11, due to the fact that a large number of negatively charged carboxyl groups are loaded on the surface of the carboxylated graphene oxide nanofiltration membrane sheet, the interlayer spacing of the carboxylated graphene oxide nanofiltration membrane is easily affected by the pH value of the environment, and under a neutral condition, the interlayer spacing of the carboxylated graphene oxide nanofiltration membrane is as follows
Under acidic conditions at pH 1, the interlayer spacing decreases to
Under the alkaline condition of pH 13, under the deprotonation effect, the interlayer spacing exceeds the upper limit of the detection of XRD
Therefore, the spectrogram shows a straight line, which indicates that the interlayer spacing can be greatly increased by carboxyl, and an effective way is provided for increasing the water flux.
10. SEM images of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane
The experimental result is shown in fig. 12, the surface of the graphene oxide nanofiltration membrane contains obvious wrinkles, and the number of the wrinkles is obviously increased compared with that of the carboxylated graphene oxide nanofiltration membrane, because in the membrane preparation process through vacuum filtration, the carboxylated graphene oxide nanofiltration membrane layer containing a large number of carboxyl groups contains a large number of negative charges on the surface, so that the sheet layer is stretched in water as much as possible, and the graphene oxide nanofiltration membrane sheet layer containing a large number of hydroxyl groups causes a large number of wrinkles due to mutual attraction of hydrogen bonds of groups in the surface.
11. Water flux of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane
The experimental result is shown in fig. 13, and the water flux of the graphene oxide nanofiltration membrane is 7.22Lm-2h-1bar-1The water flux of the carboxylated graphene oxide nanofiltration membrane is increased to 9.19Lm after the interlamellar spacing of the carboxylated graphene oxide nanofiltration membrane is improved under the action of electrostatic repulsion-2h-1bar-1。
12. Curve of change of removal rate of dye tripterygium blue with filtrate volume of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane
As shown in fig. 14, in the filtration experiment of the tricresyl blue, the removal rate of the graphene oxide nanofiltration membrane is higher than that of the carboxylated graphene oxide nanofiltration membrane, and the interlayer spacing of the carboxylated graphene oxide nanofiltration membrane is higher than that of the graphene oxide nanofiltration membrane, so that the organic dye molecules are easier to pass through the interlayer channel. However, as seen from the final result, after 60mL of 20ppm of the tritolyl blue solution is filtered, the removal rate is not much different, and is 99.12% of the graphene oxide nanofiltration membrane and 99.10% of the carboxylated graphene oxide nanofiltration membrane respectively.
13. Graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane circulation test for removing rate of Triflozin blue
The experimental result is shown in fig. 15, the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane run for 5 cycles of a cycle test, the line graph of the tripterygium blue removal rate along with the change of the volume of the filtrate is obtained, before the next cycle test, the nanofiltration membrane is washed by pure water and subjected to pressure filtration for 1 hour, and then the next cycle is carried out, the triterygium blue removal rate can be recovered to a certain degree, but the whole trend is still continuously reduced, because the organic micromolecules of the triterygium blue block the channels in the membrane and are not easy to be cleaned, the washing action is more that the organic micromolecules on the surface of the membrane are removed, and the pure water pressure filtration can only discharge a small amount of dye molecules blocked in the membrane. Meanwhile, the removal rate of the tritolyl blue of the carboxylated graphene oxide nanofiltration membrane is always higher than that of the graphene oxide nanofiltration membrane (the final removal rate is 92.29% of the carboxylated graphene oxide nanofiltration membrane and 74.58% of the graphene oxide nanofiltration membrane respectively). Moreover, the flux of the graphene oxide nano-filtration membrane is higher than that of a graphene oxide nano-filtration membrane, so that the mechanism of trapping the tritolyl blue is not only size screening, but also the action of classical rejection.
14. Final flux test after circulation of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane
The experimental result is shown in fig. 16, five times of cycle experiments are performed by using the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane, each cycle experiment filters 60mL of 20mg/mL of the trityl blue solution, and finally the flux of the trityl blue solution is reduced compared with the flux of the initial pure water, which is caused by the fact that organic micromolecules of the trityl blue block inter-membrane channels in the filtration process. However, the dye flux of the carboxylated graphene oxide nanofiltration membrane is still higher than that of the graphene oxide nanofiltration membrane, and is respectively 3.74 and 1.96L m-2h-1bar-1Due to the increased interlayer spacing caused by electrostatic repulsion.
15. Control experiment before and after surface filtration and after cleaning of graphene oxide nanofiltration membrane and carboxylated graphene oxide nanofiltration membrane
The experimental result is shown in fig. 17, and before filtration, the surfaces of the graphene oxide nanofiltration membrane and the carboxylated graphene oxide nanofiltration membrane have no color impurity; after filtration, a large amount of small molecules of the Triflozin blue are attached, and the membrane presents uniform bluish purple; after the washing by pure water, the surface of the carboxylated graphene oxide nanofiltration membrane is basically washed clean, a small amount of residual dye presents bluish purple, and a large amount of dye molecules are attached to the surface of the graphene oxide nanofiltration membrane to present blue speckles. The results show that in the presence of a large amount of negative charge carboxyl, the negative charge Triflozin blue dye molecules are not easy to attach to the surface of the membrane to pollute the membrane under the action of electrostatic repulsion.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (8)
1. A preparation method of an efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane is characterized by comprising the following steps:
s1: preparing graphene oxide into a graphene oxide dispersion liquid by using pure water;
s2: adding HBr into the graphene oxide dispersion liquid, and stirring and reacting for 10-15 h;
s3: after the reaction of the step S2, adding oxalic acid into the reaction system, continuously stirring and reacting for 2-6 h, and taking a reaction product;
s4: carrying out centrifugal purification on the reaction product obtained in the step S3 to obtain carboxylated graphene oxide;
s5: preparing the carboxylated graphene oxide obtained in the step S4 into a carboxylated graphene oxide dispersion liquid, and performing suction filtration on the carboxylated graphene oxide dispersion liquid on a polyvinylidene fluoride support membrane to obtain a carboxylated graphene oxide nanofiltration membrane;
the specific operation of the centrifugal purification in S4 is as follows:
s41, centrifuging the reaction product obtained in the step S3 at 10000 rpm, taking the precipitate, and cleaning the precipitate by pure water;
s42, centrifuging the sediment cleaned in the step S41 at 10000 r/min, taking the sediment, and cleaning the sediment by pure water;
and S43, centrifuging the precipitate cleaned in the step S42 at 10000 rpm, taking the precipitate, and cleaning the precipitate with pure water to obtain the carboxylated graphene oxide.
2. The method according to claim 1, wherein the ratio of S5: and preparing the carboxylated graphene oxide obtained in the step S4 into a carboxylated graphene oxide dispersion liquid, wherein the concentration of the carboxylated graphene oxide dispersion liquid is 0.05 mg/mL.
3. The preparation method according to claim 1, wherein the carboxylated graphene oxide dispersion liquid in S5 further comprises diluting the carboxylated graphene oxide dispersion liquid with pure water, stirring and ultrasonically dispersing the diluted carboxylated graphene oxide dispersion liquid before suction filtration.
4. The method according to claim 1, wherein in step S3, oxalic acid is added to the reaction system and the reaction is continued for 4 hours with stirring to obtain the reaction product.
5. The method according to claim 1, wherein in step S2, HBr is added to the graphene oxide dispersion, and the mixture is stirred at 1000 rpm at room temperature for 12 hours.
6. The preparation method according to claim 1, wherein the graphene oxide in the step S1 has a monolayer size of 15 μm or less.
7. The efficient and anti-fouling carboxylated graphene oxide nanofiltration membrane prepared by the preparation method according to claim 1.
8. The use of a high efficiency, anti-fouling carboxylated graphene oxide nanofiltration membrane according to claim 7 in organic wastewater treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911089492.5A CN110773000B (en) | 2019-11-08 | 2019-11-08 | Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911089492.5A CN110773000B (en) | 2019-11-08 | 2019-11-08 | Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110773000A CN110773000A (en) | 2020-02-11 |
| CN110773000B true CN110773000B (en) | 2021-09-24 |
Family
ID=69389962
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911089492.5A Active CN110773000B (en) | 2019-11-08 | 2019-11-08 | Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110773000B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116442615A (en) * | 2023-06-14 | 2023-07-18 | 汕头市兴裕泰纺织有限公司 | Cool antibacterial fabric containing inorganic composite nylon, and preparation method and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104028115A (en) * | 2014-06-03 | 2014-09-10 | 上海应用技术学院 | Carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane and preparation method thereof |
| KR20160123187A (en) * | 2015-04-15 | 2016-10-25 | 한국화학연구원 | Nanocomposite ultrafiltration membrane containing graphene oxide or reduced graphene oxide and preparation method thereof |
| CN107297154A (en) * | 2017-06-05 | 2017-10-27 | 浙江工业大学 | A kind of carboxylated graphene oxide NF membrane and its preparation and application |
| CN108786499A (en) * | 2018-06-15 | 2018-11-13 | 武汉工程大学 | The preparation method of the controllable carboxylated graphene oxide NF membrane of flux |
| CN110152502A (en) * | 2019-03-20 | 2019-08-23 | 天津市水利工程有限公司 | A kind of novel environment friendly graphene oxide membrane and preparation method |
| CN110201556A (en) * | 2019-05-21 | 2019-09-06 | 西南石油大学 | A kind of graphene oxide nanofiltration membrane, preparation method and applications slightly restored |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016011124A1 (en) * | 2014-07-17 | 2016-01-21 | The Research Foundation For The State University Of New York | Porous graphene based composite membranes for nanofiltration, desalination, and pervaporation |
-
2019
- 2019-11-08 CN CN201911089492.5A patent/CN110773000B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104028115A (en) * | 2014-06-03 | 2014-09-10 | 上海应用技术学院 | Carboxylation graphene oxide/polyvinylidene fluoride compiste ultrafiltration membrane and preparation method thereof |
| KR20160123187A (en) * | 2015-04-15 | 2016-10-25 | 한국화학연구원 | Nanocomposite ultrafiltration membrane containing graphene oxide or reduced graphene oxide and preparation method thereof |
| CN107297154A (en) * | 2017-06-05 | 2017-10-27 | 浙江工业大学 | A kind of carboxylated graphene oxide NF membrane and its preparation and application |
| CN108786499A (en) * | 2018-06-15 | 2018-11-13 | 武汉工程大学 | The preparation method of the controllable carboxylated graphene oxide NF membrane of flux |
| CN110152502A (en) * | 2019-03-20 | 2019-08-23 | 天津市水利工程有限公司 | A kind of novel environment friendly graphene oxide membrane and preparation method |
| CN110201556A (en) * | 2019-05-21 | 2019-09-06 | 西南石油大学 | A kind of graphene oxide nanofiltration membrane, preparation method and applications slightly restored |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110773000A (en) | 2020-02-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106076132B (en) | A kind of graphene oxide modified polyamide composite nanometer filtering film and preparation method thereof | |
| Vatanpour et al. | Enhancing the permeability and antifouling properties of cellulose acetate ultrafiltration membrane by incorporation of ZnO@ graphitic carbon nitride nanocomposite | |
| US10118151B2 (en) | Composite with synergistic effect of adsorption and visible light catalytic degradation and preparation method and application thereof | |
| CN106178979B (en) | High-performance two-dimensional stratiform Ti3C2- MXene film and preparation method thereof and the application in water process | |
| CN107469633B (en) | Method for preparing membrane with enhanced water flux | |
| CN105617882B (en) | A kind of compound forward osmosis membrane of chitosan-modified stannic oxide/graphene nano and preparation method thereof | |
| US10710025B2 (en) | Inorganic fibrous membrane and a method of fabricating thereof | |
| CN107321197B (en) | Composite nanofiltration membrane and preparation method thereof | |
| CN110026092B (en) | Nano composite membrane for heavy metal interception and preparation method thereof | |
| Zhang et al. | Fluffy-like amphiphilic graphene oxide (f-GO) and its effects on improving the antifouling of PAN-based composite membranes | |
| CN110773000B (en) | Efficient and anti-pollution carboxylated graphene oxide nanofiltration membrane, and preparation method and application thereof | |
| CN108786464A (en) | The preparation method for graphene oxide NF membrane that flux is adjustable | |
| CN113019151B (en) | Graphene oxide-polyvinylidene fluoride composite hollow fiber membrane for water treatment, and preparation method and application thereof | |
| CN111330464A (en) | Preparation method of blending modified polysulfone charged nanofiltration membrane and obtained membrane | |
| Ma et al. | Hydrophilic PAA-g-MWCNT/TiO2@ PES nano-matrix composite membranes: Anti-fouling, antibacterial and photocatalytic | |
| CN112354378A (en) | Layered MoS2Nano graphene oxide membrane reduced by blending nanosheets and preparation method thereof | |
| CN111036082B (en) | Graphene oxide/TiO2Method for preparing composite membrane | |
| CN112588115B (en) | Fusiform MXene-carbon nanotube two-dimensional film and preparation method and application thereof | |
| Kusworo et al. | Purification of bioethanol fermentation broth using hydrophilic PVA crosslinked PVDF-GO/TiO2 membrane | |
| WO2015060782A1 (en) | Graphene oxide/polymer composite membranes and methods of forming thereof | |
| CN114669199A (en) | Modified mica sheet-nanocellulose composite nanofiltration membrane and preparation method thereof | |
| Zhai et al. | Self-cleaning catalytic membrane with super-wetting interface for high-efficiency oil-in-water emulsion separation | |
| Zhou et al. | Anti-fouling PVDF membranes incorporating photocatalytic biochar-TiO2 composite for lignin recycle | |
| CN114130197A (en) | Graphene oxide titanium dioxide-dopamine PEI nanofiltration membrane and preparation method thereof | |
| CN113522039A (en) | Preparation method of forward osmosis membrane based on PVA (polyvinyl alcohol) grafting modification |
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 |