CN115869780A - Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof - Google Patents
Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof Download PDFInfo
- Publication number
- CN115869780A CN115869780A CN202211660810.0A CN202211660810A CN115869780A CN 115869780 A CN115869780 A CN 115869780A CN 202211660810 A CN202211660810 A CN 202211660810A CN 115869780 A CN115869780 A CN 115869780A
- Authority
- CN
- China
- Prior art keywords
- membrane
- positively charged
- dimensional
- pouring
- water
- 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.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/124—Water desalination
- Y02A20/131—Reverse-osmosis
Landscapes
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention discloses a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial, a preparation method and application thereof 2 Grafting the two-dimensional nano material to make the surface of the membrane positive. The amino grafted two-dimensional nano material positively charged nanofiltration membrane prepared by the method has good hydrophilicity and provides an additional channel for filtration. The prepared nanofiltration membrane can improve water flux on one hand and improve NH on the other hand 2 Grafting of the two-dimensional nanomaterial makes the membrane surface positively charged, making Ca 2+ 、Mg 2+ Ions are removed by the Donnan effect. Meanwhile, the membrane pollution problem is improved, the service life of the membrane is prolonged, the cost is reduced, and a better prospect is provided for the application of the two-dimensional nano material in the field of sewage treatment.
Description
Technical Field
The invention relates to a positively charged nanofiltration material added based on a modified two-dimensional nanomaterial, a preparation method and application thereof, and belongs to the technical field of separation membrane materials.
Background
The nano-filtration technology has the advantages of low cost, high efficiency and the like, and is an effective method for solving the problem of water purification. Generally speaking, the method has the advantages of low cost, easy operation and relatively simple preparation process. Most of the existing nanofiltration membranes are electronegative or electroneutral, can realize effective separation of single-multivalent anions in the water body, but have poor separation effect on single-multivalent cations in the water body. However, researches in recent years find that the positively charged nanofiltration membrane not only has good acid and alkali resistance, corrosion resistance and hydrophilicity, but also can resist Ca through Tao nan electrostatic repulsion and size repulsion effects 2+ 、Na + The cations with different valence states show excellent repellency so as to solve the problems of amino acid and protein separation, cathode electrophoretic paint waste liquid treatment, positive charge dye waste water treatment and the like. Therefore, the development and application of the positively charged nanofiltration membrane are becoming the research hotspots in the field of water treatment. But there is relatively little commercial positively charged nanofiltration membrane product compared to negatively charged separation membranes. Currently, most researchers expect to obtain a positively charged NF membrane with excellent performances by innovating membrane preparation materials and preparation processes.
The common excellent positively charged nanofiltration membrane forming materials at present comprise chitosan materials, polyethyleneimine materials and quaternary ammonium salt materials, and the research on the preparation process mainly focuses on an IP method, a layer-by-layer assembly method, a grafting method, a crosslinking method and the like. N, N-dimethylaminoethyl methacrylate (DMAEMA) is grafted on a PSF base membrane by an ultraviolet ray induction method, and then the NF membrane with an electropositive surface is prepared by carrying out quaternization combination on dichlorobenzyl. The research shows that the modified membrane has obviously enhanced hydrophilicity, and the membrane flux is 6.03L.m under the optimal condition -2 .h -1 .bar -1 To MgCl 2 The retention of the solution reached 93.2% (Liang Yu. Journal of Hazardous materials. 2015); ziabawei uses polysulfone ultrafiltration membrane as bottom membrane, and uses piperazine anddiaminodipropylamine is used as a water phase monomer, trimesoyl chloride is used as an oil phase monomer to prepare an original ecological nanofiltration membrane, and then 2-chloro-1-methyl iodopyridine and sodium hydroxide are used as active agents to prepare a positively charged nanofiltration membrane (Qiabao, shuoshi academic thesis, zhejiang university of industry, 2019) by grafting polyethyleneimine on the surface of the nanofiltration membrane. The methods have obvious advantages, but have the problems of low water flux, high preparation process requirement and the like.
Meanwhile, in recent years, new two-dimensional materials have been emerging, and functional characteristics thereof have been attracting much attention from successful exfoliation of graphene to design and synthesis of frame materials. The two-dimensional material has a large diameter-thickness ratio, and is favorable for assembly to form an ordered interlayer and in-plane channel structure, and the characteristic provides possibility for preparing the high-performance nanofiltration membrane.
Two-dimensional separation membranes represented by graphene (graphene) and derivatives thereof attract attention of a plurality of researchers due to unique physicochemical properties brought by the size of the two-dimensional separation membranes, and the membrane performance of the two-dimensional separation membranes is far higher than that of a traditional membrane, and shows a mass transfer separation mechanism which is different from that of the traditional membrane. Representative materials include graphene, molybdenum disulfide, tungsten disulfide, graphite phase carbon nitride, ti 3 C 2 T x Etc. are widely used in current nanofiltration studies. The nanofiltration membrane prepared by the nano materials has higher water flux, high interception rate of small molecular pollutants and good flexibility, and effectively ensures the water flux and the interception effect of the nanofiltration membrane.
Ten string et al synthesized single layer titanium carbide (Ti) by lithium fluoride/dilute hydrochloric acid etching of titanium aluminum carbide 3 C 2 T x ) Nanosheet, and further preparing a Ti by adopting an interfacial polymerization method 3 C 2 T x The doped polyamide thin-layer composite nanofiltration membrane improves the pure water flux of the nanofiltration membrane while keeping the rejection rate of sodium sulfate salt to be 98% (Zhangiang, wuming board, yanxi, yanjing, xushikang. Membrane science and technology, 2020, (01): 8-15.); zhao rui general MoS 2 The influence of the polymerization of the nanosheet doped in the water phase interface on the physicochemical property and the permeation/separation performance of the TFC membrane. The results show that the MoS is doped with the aqueous phase 2 Nano-sheetThe concentration of (A) was increased to 0.01wt%, the surface roughness, hydrophilicity and electronegativity of the constructed TFN membrane were increased, and the rejection rate of sodium sulfate was also increased (Zhao Rui, ph's Biochem, harbin university of industry, 2021.).
Although the rejection rate and water flux can be improved by the two-dimensional nano material nanofiltration membrane, the simple two-dimensional nano material can not meet the treatment of divalent cations. Because most of the nano materials are electronegative, the prepared composite nanofiltration membrane also has the property of negative charge, SO that the obtained nanofiltration membrane material is used for divalent anions (SO) 4 2 -、CO 3 2- ) Has better retaining capacity to Ca 2+ 、Mg 2+ The plasma hardness ion trapping capability is poor. Therefore, the charged nanofiltration membrane is developed through the Donan effect, and is an important direction for applying the two-dimensional nano material to the nanofiltration membrane. Relevant reports are not retrieved yet by the technology of the positively charged nanofiltration membrane material based on the addition of the two-dimensional nano material.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the limitation of practical application of a two-dimensional nano material in the field of separation membranes, the invention provides a preparation method of an amino-grafted two-dimensional nano material positively-charged nanofiltration membrane for removing calcium and magnesium ions.
The invention also provides a positively charged nanofiltration material prepared by the preparation method based on the addition of the modified two-dimensional nanomaterial.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
a preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
step one, dispersing 200-300mg of two-dimensional nano material in 80-100mL of deionized water, and performing ultrasonic treatment for 1-2h to obtain a dispersion solution; placing the dispersion solution in a water bath at 60-65 ℃, adding 1-2g of p-phenylenediamine and 1-3mL of isoamyl nitrite into the dispersion solution, heating and stirring in the water bath for reaction for 10-12h, and cooling the reaction solution to room temperature after the reaction is finished;
centrifuging the cooled reaction solution until the pH of the supernatant is 7, and freeze-drying the reaction solution in a freezer for at least 48 hours to obtain the amino grafted two-dimensional nanomaterial; preparing 1.2-1.5g/L of dispersion liquid by using deionized water for the amino grafted two-dimensional nano material;
preparing piperazine PIP and polyethyleneimine PEI into mixed solution with the percentage contents of 2.0-2.2% and 2.7-3.0% respectively by using deionized water, measuring dispersion liquid, and adding the dispersion liquid into the mixed solution, wherein the adding volume of the dispersion liquid is 9-20% of the volume of the deionized water; performing ultrasonic treatment for 15-30min to obtain water phase;
weighing 0.1-0.3g of trimesoyl chloride TMC, pouring into a beaker, and putting into a drying oven to melt the trimesoyl chloride into a liquid phase;
measuring 100-150mL of normal hexane, adding the normal hexane into a beaker containing trimesoyl chloride TMC, and performing ultrasonic dispersion for 10-20min to obtain an oil phase;
fixing the polysulfone support membrane in a reaction tank, pouring the water phase, soaking for 4-6min, pouring out the water phase, and airing in the air;
step seven, pouring the oil phase, soaking for 1-2min, pouring out the oil phase, and airing;
and step eight, taking out the air-dried polysulfone support membrane obtained in the step seven, placing the polysulfone support membrane into a culture dish, carrying out heat treatment in an oven, taking out the polysulfone support membrane, cooling the polysulfone support membrane to room temperature, pouring the polysulfone support membrane into deionized water, cutting and soaking the deionized water to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane.
In the first step, the two-dimensional nano material is graphene and MoS 2 ，WS 2 Graphite phase carbon nitride g-C 3 N 4 Two-dimensional titanium carbide Ti 3 C 2 T x Any one or more of them.
In the fourth step, the process of putting the mixture into an oven to melt the mixture into a liquid phase comprises the following steps: hot melting in oven at 50-60 deg.C for 5-10min.
In the eighth step, the size of the culture dish is 250mm multiplied by 250mm, the heat treatment temperature of the oven is 60-65 ℃, and the treatment time is 5-10min.
The positively charged nanofiltration material based on the addition of the modified two-dimensional nanomaterial is obtained by the preparation method.
A positively charged nanofiltration material based on modified two-dimensional nanomaterials is added, and the water flux of the positively charged nanofiltration material under the pressure of 4bar is 26.57-32.10 Lm -2 h -1 ；Ca 2+ And Mg 2+ The retention rate of the catalyst is 95.69-97.23%.
An application of a positively charged nanofiltration material added based on a modified two-dimensional nanomaterial in sewage treatment.
The sewage contains calcium and magnesium ions.
A membrane module comprises a positively charged nanofiltration material based on the addition of modified two-dimensional nanomaterials.
The design principle is as follows: the lamellar two-dimensional nanomaterial and the amino have excellent structural characteristics, can provide an additional transmission channel, so that water molecules can easily pass through the transmission channel, and simultaneously have hydrophilic functional groups so as to ensure water flux. Meanwhile, the amino grafted two-dimensional nano material enables the surface of the membrane to keep electropositivity, and Ca can be blocked due to electrostatic action 2+ 、Mg 2+ The plasma enters the membrane, and negative ions are also trapped on the membrane surface in order to maintain electrical neutrality. And because the existence of hydrophilic groups such as amino groups and the like, the surface of the membrane is covered by water, and pollutants are difficult to adsorb on the surface of the membrane, so that the pollutants adhered to the surface of the membrane can be removed by washing with deionized water.
The design idea is as follows: at present, positively charged nanofiltration membranes are applied to water treatment projects such as high-salinity wastewater and the like due to the high rejection rate of positively charged ions. The serious membrane pollution and the contradiction between the water flux and the salt rejection rate are increasingly obvious. The invention aims to remove Ca 2+ 、Mg 2+ Meanwhile, the water flux is effectively ensured, and the pollutant attachment is reduced. The design is carried out around the idea of effectively removing positive ions and reducing the attachment of pollutants by introducing NH 2 Grafting two-dimensional nano material to make the surface of the membrane be electropositive, introducing PIP and the like to reduce the roughness of the surface of the membrane and reduce the attachment of pollutants, namely Ca 2+ 、Mg 2+ The positive ions have high retention rate and are resistant to pollution.
The advantages are that: by NH 2 Grafting two-dimensional nano material to make the membrane surface be electropositive to Ca 2+ 、Mg 2+ Has excellent interception effect, provides additional channels, improves water flux, and reduces the attachment of pollutants.
Has the advantages that: compared with the prior art, the invention has the following advantages:
the amino grafted two-dimensional nano material positively charged nanofiltration membrane prepared by the method has good hydrophilicity and provides an additional channel for filtration. The prepared nanofiltration membrane can improve water flux on one hand and improve NH on the other hand 2 Grafting of the two-dimensional nanomaterial makes the membrane surface positively charged, making Ca 2+ 、Mg 2+ Ions are effectively removed by the Donnan effect. Meanwhile, the membrane pollution problem is improved, the service life of the membrane is prolonged, the cost is reduced, and a better prospect is provided for the application of the two-dimensional nano material in the field of sewage treatment.
Drawings
FIG. 1 shows Ti obtained in example 1 of the present invention 3 C 2 T x Contact angle test chart of nanofiltration membrane material.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely illustrative of the invention and are not intended to be limiting.
The experimental methods described in the examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
Example 1
A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
1) Mixing Ti 3 C 2 T x Dispersing 200mg in 80mL deionized water, and performing ultrasonic treatment for 1h;
2) Placing the solution obtained in the step 1) in a water bathIn the apparatus, 1g of p-phenylenediamine and 1mL of isoamyl nitrite were added to the solution, and the mixture was heated and stirred at 60 ℃ for 10 hours. Cooling the product to room temperature after the reaction is finished, centrifuging the solution until the pH of the supernatant is 7 (the specific process comprises centrifuging the solution, removing the supernatant, adding deionized water, mixing, continuing to centrifuge until the pH of the supernatant is 7), and freeze-drying in a dryer for 48h to obtain Ti 3 C 2 T x -NH 2 (ii) a Mixing Ti 3 C 2 T x -NH 2 Preparing 1.2g/L dispersion liquid;
3) 2.4g of piperazine (PIP) and 3.0g of Polyethyleneimine (PEI) are respectively weighed, and after 110mL of deionized water is added, ultrasonic treatment is carried out for 15min;
4) Adding 10mL of Ti into the solution obtained in the step 3) 3 C 2 T x -NH 2 Mixing the dispersion, and performing ultrasonic treatment for 15min to obtain water phase;
5) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and putting into a 60 ℃ oven for 5min to melt the trimesoyl chloride into a liquid phase;
6) Measuring 100mL of n-hexane, adding into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
7) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 5), soaking for 4min, pouring out the solution, and airing in the air;
8) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
9) And taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape (the specific shape is the shape required by a measuring machine and is cut according to the requirement of a measuring instrument), and soaking the membrane to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane marked as M1.
An application of a positively charged nanofiltration material added based on a modified two-dimensional nanomaterial in sewage treatment, wherein the sewage contains calcium and magnesium ions.
A membrane module comprising a positively charged nanofiltration material based on the addition of modified two-dimensional nanomaterials of this embodiment.
Analyzing and observing the taken sample M1 by a scanning electron microscope and the like, and applying the sample M1 to CaCl 2 The separation performance and water flux of (2) were investigated.
According to Table 1, when Ti 3 C 2 T x -NH 2 When the addition amount reaches 0.01%, the addition amount is adjusted to Ca 2+ The retention rate and the water flux of the filter are respectively 96.58 percent and 32.10Lm -2 h -1 (4 bar), compared with the condition that the two-dimensional nano material is not added, ti is added 3 C 2 T x -NH 2 After that, the retention rate is increased, and the water flux of the membrane is obviously improved.
Ti 3 C 2 T x -NH 2 The method for calculating the addition amount comprises the following steps: (1.2 g/L × 10 mL/1000)/(110mL + 10mL) × 100% =0.01%.
As shown in FIG. 1, ti obtained in this example was used 3 C 2 T x Contact angle test chart of the nanofiltration membrane material shows that the contact angle of the material is larger, which indicates good hydrophilicity.
Example 2
A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
1) Mixing Ti 3 C 2 T x Dispersing 200mg in 80mL deionized water, and performing ultrasonic treatment for 1h;
2) Putting the solution obtained in the step 1) into a water bath device, adding 1g of p-phenylenediamine and 1ml of isoamyl nitrite into the solution, setting the temperature of the water bath to be 60 ℃, and heating and stirring for 10 hours. After the reaction is finished, cooling the product to room temperature, centrifuging the solution until the pH of the supernatant is 7, and placing the solution in a freezer for freeze-drying for 48 hours to obtain Ti 3 C 2 T x -NH 2 (ii) a Mixing Ti 3 C 2 T x -NH 2 Preparing 1.2g/L dispersion liquid;
3) 2.4g of piperazine (PIP) and 3.0g of Polyethyleneimine (PEI) are respectively weighed, 105mL of deionized water is added, and ultrasonic treatment is carried out for 15min;
4) Adding 15mL of Ti into the solution obtained in the step 3) 3 C 2 T x -NH 2 Mixing the dispersion, and performing ultrasonic treatment for 15min to obtain water phase;
Ti 3 C 2 T x -NH 2 the addition amount calculation method comprises the following steps: (1.2 g/L × 15 mL/1000)/(105mL + 15mL) × 100% =0.015%;
5) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and putting into a 60 ℃ oven for 5min to melt the trimesoyl chloride into a liquid phase;
6) Measuring 100mL of n-hexane, adding into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
7) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 5), soaking for 4min, pouring out the solution, and airing in the air;
8) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
9) And taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape, and soaking the membrane to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane marked as M2.
Analyzing and observing the taken sample M2 by a scanning electron microscope and the like, and applying the sample to CaCl 2 /MgCl 2 The separation performance and water flux of (2) were investigated.
Example 3
A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
1) Mixing Ti 3 C 2 T x Dispersing 200mg in 80mL deionized water, and performing ultrasonic treatment for 1h;
2) Putting the solution obtained in the step 1) into a water bath device, adding 1g of p-phenylenediamine and 1ml of isoamyl nitrite into the solution, setting the temperature of the water bath to be 60 ℃, and heating and stirring for 10 hours. After the reaction is finished, cooling the product to room temperature, centrifuging the solution until the pH of the supernatant is 7, and placing the solution in a freezer for freeze-drying for 48 hours to obtain Ti 3 C 2 T x -NH 2 (ii) a Mixing Ti 3 C 2 T x -NH 2 The dispersion was prepared at 1.2g/L；
3) 2.4g of piperazine (PIP) and 3.0g of Polyethyleneimine (PEI) are respectively weighed, 100mL of deionized water is added, and ultrasonic treatment is carried out for 15min;
4) Adding 20mL of Ti into the solution obtained in the step 3) 3 C 2 T x -NH 2 Mixing the dispersion, and performing ultrasonic treatment for 15min to obtain water phase;
Ti 3 C 2 T x -NH 2 the method for calculating the addition amount comprises the following steps: (1.2 g/L × 20 mL/1000)/(100mL + 20mL) × 100% =0.02%;
5) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and placing in a drying oven at 60 ℃ for 5min to melt the trimesoyl chloride into a liquid phase;
6) Measuring 100ml of n-hexane, adding the n-hexane into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
7) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 5), soaking for 4min, pouring out the solution, and airing in the air;
8) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
9) Taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape, and soaking the membrane to obtain the organic-inorganic hybrid positively charged nanofiltration membrane marked as M3;
analyzing and observing the taken sample M3 by a scanning electron microscope and the like, and applying the sample M3 to CaCl 2 /MgCl 2 The separation performance and water flux of (2) were investigated.
Example 4
A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
1) Mixing graphene (or MoS) 2 ，WS 2 Graphite phase carbon nitride (g-C) 3 N 4 ) 200mg of the mixture is dispersed in 80mL of deionized water and is subjected to ultrasonic treatment for 1h;
2) Putting the solution obtained in the step 1) into a water bath device, adding 1g of p-phenylenediamine and 1ml of isoamyl nitrite into the solution, setting the temperature of the water bath to be 60 ℃, and heating and stirring for 10 hours. After the reaction is finished, cooling the product to room temperature, centrifuging the solution until the pH of the supernatant is 7, and placing the solution in a freezer for freeze-drying for 48 hours to prepare 1.2g/L dispersion;
3) 2.4g of piperazine (PIP) and 3.0g of Polyethyleneimine (PEI) are respectively weighed, 100mL of deionized water is added, and ultrasonic treatment is carried out for 15min;
4) Adding 20mL of graphene-NH into the solution obtained in the step 3) 2 (or MoS) 2 -NH 2 ，WS 2 -NH 2 、g-C 3 N 4 -NH 2 ) Dispersing the liquid, mixing, and performing ultrasonic treatment for 15min to obtain water phase;
5) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and putting into a 60 ℃ oven for 5min to melt the trimesoyl chloride into a liquid phase;
6) Measuring 100mL of n-hexane, adding into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
7) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 5), soaking for 4min, pouring out the solution, and airing in the air;
8) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
9) Taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape, and soaking the membrane to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane marked as M4;
analyzing and observing the taken sample M4 by a scanning electron microscope and the like, and applying the sample M4 to CaCl 2 /MgCl 2 The separation performance and water flux of (2) were investigated.
Example 5
A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial comprises the following steps:
1) Mixing Ti 3 C 2 T x 300mg is dispersed in 100mL deionized water and ultrasonic treatment is carried out for 2h;
2) Putting the solution obtained in the step 1) into a water bath device, and adding2g of p-phenylenediamine and 3mL of isoamyl nitrite are added into the solution, the temperature of a water bath is set to 65 ℃, and the solution is heated and stirred for 12 hours. After the reaction is finished, cooling the product to room temperature, centrifuging the solution until the pH of the supernatant is 7, and placing the solution in a freezer for freeze-drying for 60 hours to obtain Ti 3 C 2 T x -NH 2 (ii) a Mixing Ti 3 C 2 T x -NH 2 Preparing 1.5g/L dispersion liquid;
3) 2.2g of piperazine (PIP) and 3.3g of Polyethyleneimine (PEI) are respectively weighed, 110mL of deionized water is added, and ultrasonic treatment is carried out for 30min;
4) Adding 10mL of Ti into the solution obtained in the step 3) 3 C 2 T x -NH 2 Mixing the dispersion, and performing ultrasonic treatment for 30min to obtain water phase;
Ti 3 C 2 T x -NH 2 the addition amount calculation method comprises the following steps: (1.5 g/L × 10 mL/1000)/(110mL + 10mL) × 100% =0.0125%;
5) Weighing 0.3g of trimesoyl chloride (TMC), pouring into a beaker, and putting into a 50 ℃ oven for 10min to melt the trimesoyl chloride into a liquid phase;
6) Measuring 150mL of normal hexane, adding into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 20min to prepare an oil phase solution required by an experiment;
7) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 5), soaking for 6min, pouring out the solution, and airing in the air;
8) Pouring the oil phase solution, soaking for 2min, pouring out the solution, and air drying;
9) And taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 65 ℃ for 10min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the deionized water, and soaking the membrane to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane.
Comparative example 1
A preparation method of a nano-filtration membrane without adding nano-materials comprises the following preparation steps:
1) 2.4g of piperazine (PIP) and 3.0g of Polyethyleneimine (PEI) are respectively weighed, 120mL of deionized water is added, and ultrasonic treatment is carried out for 15min to prepare an aqueous phase solution required by an experiment;
2) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and putting into a 60 ℃ oven for 5min to melt the trimesoyl chloride into a liquid phase;
3) Measuring 100mL of n-hexane, adding into a beaker containing trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
4) Fixing a polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 1), soaking for 4min, pouring out the solution, and airing in the air;
5) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
6) Taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape, and soaking the membrane to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane, wherein the M0 is marked;
comparative example 2
A preparation method of nano material added nanofiltration membrane comprises the following steps:
1) Piperazine (PIP) 2.4g and Polyethyleneimine (PEI) 3.0g were weighed, respectively, and after adding 110mL of deionized water, sonication was carried out for 15min.
2) Adding nano TiO into the solution after ultrasonic treatment 2 10mL to prepare aqueous phase solution required by the experiment;
3) Weighing 0.1g of trimesoyl chloride (TMC), pouring into a beaker, and placing in a drying oven at 60 ℃ for 5min to melt the trimesoyl chloride into a liquid phase;
4) Measuring 100mL of normal hexane, adding the normal hexane into a beaker filled with trimesoyl chloride, and performing ultrasonic dispersion for 10min to prepare an oil phase solution required by an experiment;
5) Fixing the polysulfone support membrane in a reaction tank, pouring the polysulfone support membrane into the aqueous phase solution prepared in the step 2), soaking for 4min, pouring out the solution, and airing in the air;
6) Pouring the oil phase solution, soaking for 1min, pouring out the solution, and air drying;
7) And taking out the dried membrane, placing the membrane in a culture dish with the size of 250mm multiplied by 250mm, carrying out heat treatment in an oven at 60 ℃ for 5min, taking out the membrane, cooling to room temperature, pouring the membrane into deionized water, cutting the membrane into a specific shape, and soaking the membrane to obtain the organic-inorganic hybrid positively charged nanofiltration membrane marked as M01.
Nano TiO in this comparative example 2 Is common nanometer material and non-two-dimensional nanometer material.
Separation performance experiments:
table 1 shows the water flux (4 bar) and retention rate table of the amino grafted two-dimensional nanomaterial positive charge nanofiltration membrane material obtained under the experimental parameters. It can be seen that under the condition of ensuring relatively high interception, the interception rate and water flux of the nanofiltration membrane can be effectively improved by adding the amino grafted two-dimensional nano material 2 /MgCl 2 In solution, caCl 2 And MgCl 2 The concentrations of (A) and (B) were all 2000mg/L.
TABLE 1 Water flux and Retention Rate tables
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (9)
1. A preparation method of a positively charged nanofiltration material based on addition of a modified two-dimensional nanomaterial is characterized by comprising the following steps: the method comprises the following steps:
step one, dispersing 200-300mg of two-dimensional nano material in 80-100mL of deionized water, and performing ultrasonic treatment for 1-2h to obtain a dispersion solution; placing the dispersion solution in a water bath at 60-65 ℃, adding 1-2g of p-phenylenediamine and 1-3mL of isoamyl nitrite into the dispersion solution, heating and stirring in the water bath for reaction for 10-12h, and cooling the reaction solution to room temperature after the reaction is finished;
centrifuging the cooled reaction solution until the pH of the supernatant is 7, and freeze-drying the reaction solution in a freezer for at least 48 hours to obtain the amino grafted two-dimensional nanomaterial; preparing 1.2-1.5g/L of dispersion liquid by using deionized water for the amino grafted two-dimensional nano material;
preparing piperazine PIP and polyethyleneimine PEI into mixed solutions with percentage contents of 2.0-2.2% and 2.7-3.0% respectively by using deionized water, measuring a dispersion liquid, and adding the dispersion liquid into the mixed solutions, wherein the addition volume of the dispersion liquid is 9-20% of the volume of the deionized water; performing ultrasonic treatment for 15-30min to obtain water phase;
weighing 0.1-0.3g of trimesoyl chloride TMC, pouring into a beaker, and putting into a drying oven to melt the trimesoyl chloride into a liquid phase;
measuring 100-150mL of normal hexane, adding the normal hexane into a beaker containing trimesoyl chloride TMC, and performing ultrasonic dispersion for 10-20min to obtain an oil phase;
fixing the polysulfone support membrane in a reaction tank, pouring the water phase, soaking for 4-6min, pouring out the water phase, and airing in the air;
step seven, pouring the oil phase, soaking for 1-2min, pouring out the oil phase, and airing;
and step eight, taking out the air-dried polysulfone support membrane obtained in the step seven, placing the polysulfone support membrane into a culture dish, carrying out heat treatment in an oven, taking out the polysulfone support membrane, cooling the polysulfone support membrane to room temperature, pouring the polysulfone support membrane into deionized water, cutting and soaking the deionized water to obtain the organic-inorganic hybrid positively-charged nanofiltration membrane.
2. The method of claim 1, wherein: in the first step, the two-dimensional nano material is graphene, moS 2 ，WS 2 Graphite phase carbon nitride g-C 3 N 4 Two-dimensional titanium carbide Ti 3 C 2 T x Any one or more of them.
3. The method of claim 1, wherein: in the fourth step, the process of putting the mixture into a drying oven to melt the mixture into a liquid phase comprises the following steps: hot melting in oven at 50-60 deg.C for 5-10min.
4. The method of claim 1, wherein: in the eighth step, the size of the culture dish is 250mm multiplied by 250mm, the heat treatment temperature of the oven is 60-65 ℃, and the treatment time is 5-10min.
5. A positively charged nanofiltration material based on modified two-dimensional nanomaterials prepared by the preparation method of any one of claims 1 to 4.
6. The positively charged nanofiltration material based on the addition of modified two-dimensional nanomaterials according to claim 5, wherein: the water flux of the positively charged nanofiltration material under the pressure of 4bar is 26.57 to 32.10Lm -2 h -1 ；Ca 2+ And Mg 2+ The retention rate of the resin is 95.69 to 97.23 percent.
7. The use of the positively charged nanofiltration material added based on modified two-dimensional nanomaterials as claimed in claim 5 in wastewater treatment.
8. Use according to claim 7, characterized in that: the sewage contains calcium and magnesium ions.
9. A membrane module, characterized by: comprising a positively charged nanofiltration material based on the addition of modified two-dimensional nanomaterials according to claim 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211660810.0A CN115869780A (en) | 2022-12-23 | 2022-12-23 | Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211660810.0A CN115869780A (en) | 2022-12-23 | 2022-12-23 | Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115869780A true CN115869780A (en) | 2023-03-31 |
Family
ID=85754346
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211660810.0A Pending CN115869780A (en) | 2022-12-23 | 2022-12-23 | Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115869780A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116531961A (en) * | 2023-07-04 | 2023-08-04 | 中国农业大学 | Positively charged nanofiltration membrane for removing uranium and cesium in nuclear radioactive wastewater and preparation method thereof |
-
2022
- 2022-12-23 CN CN202211660810.0A patent/CN115869780A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116531961A (en) * | 2023-07-04 | 2023-08-04 | 中国农业大学 | Positively charged nanofiltration membrane for removing uranium and cesium in nuclear radioactive wastewater and preparation method thereof |
| CN116531961B (en) * | 2023-07-04 | 2023-09-19 | 中国农业大学 | Positively charged nanofiltration membrane for removing uranium and cesium in nuclear radioactive wastewater and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Khumalo et al. | Water recovery from hydrolysed human urine samples via direct contact membrane distillation using PVDF/PTFE membrane | |
| CN108435002B (en) | Preparation method of functionalized carbon quantum dot modified composite nanofiltration membrane | |
| Li et al. | Thin-film nanocomposite NF membrane with GO on macroporous hollow fiber ceramic substrate for efficient heavy metals removal | |
| CN115869780A (en) | Positively charged nanofiltration material added based on modified two-dimensional nanomaterial and preparation method and application thereof | |
| CN111773928B (en) | Aerogel composite membrane and preparation method and application thereof | |
| CN113522045B (en) | Preparation method and application of molybdenum disulfide nanodot hybrid nanofiltration membrane | |
| WO2021008135A1 (en) | Conductive organic membrane coupling and filtration system, and method for degrading organic waste water | |
| CN112473372A (en) | Conductive forward osmosis membrane and preparation method thereof | |
| CN114904398B (en) | Polyacrylonitrile-based uranium extraction from seawater-seawater desalination co-production membrane and preparation method thereof | |
| CN113754920A (en) | Polyimide composite aerogel, preparation method and application of polyimide composite aerogel as solar evaporator | |
| CN108295812B (en) | Graphene oxide composite membrane for selectively removing metal ions in water, and preparation method and application thereof | |
| Li et al. | Analysis of Mg2+/Li+ separation mechanism by charged nanofiltration membranes: visual simulation | |
| Barahimi et al. | Fabrication of a novel antifouling TiO 2/CPTES/metformin-PES nanocomposite membrane for removal of various organic pollutants and heavy metal ions from wastewater | |
| CN114053888B (en) | Hydrophilic conductive distillation membrane and preparation method and application method thereof | |
| Zhao et al. | Interfacial polymerization layer with CNT providing fast water channels under electric field for efficient desalination of nanofiltration membranes | |
| WO2017206579A1 (en) | Graphene micro-sheet having mesh structure and preparation method therefor | |
| CN111346576A (en) | Preparation method of graphene-based hydrogel with three-dimensional network structure and photo-thermal desalted water treatment application of graphene-based hydrogel | |
| CN114016285A (en) | Preparation method of functional nanofiber membrane for seawater desalination | |
| Wen et al. | Efficient and ultrafast separation of Li+ and Mg2+ by the porous two-dimensional nanochannel of perm-selective montmorillonite membrane | |
| Usman et al. | MXene-enhanced sulfonated TFN nanofiltration membranes for improved desalination performance | |
| Sun et al. | Enhancing TFC membrane permeability by incorporating single-layer MSN into polyamide rejection layer | |
| CN115845640B (en) | Positively charged composite nanofiltration membrane and preparation method and application thereof | |
| He et al. | La (OH) 3 nano-rods/polyacrylonitrile nanofibers: fabrication, characterization and application for phosphate removal | |
| CN109433030B (en) | Preparation method of graphene oxide quantum dot-silver phosphate composite material modified reverse osmosis composite membrane | |
| CN115350589A (en) | Polymeric nanofiltration membrane and preparation and application thereof |
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 |