CN114749039A - Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof - Google Patents
Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof Download PDFInfo
- Publication number
- CN114749039A CN114749039A CN202210604756.1A CN202210604756A CN114749039A CN 114749039 A CN114749039 A CN 114749039A CN 202210604756 A CN202210604756 A CN 202210604756A CN 114749039 A CN114749039 A CN 114749039A
- Authority
- CN
- China
- Prior art keywords
- nanofiber membrane
- super
- carbon nanofiber
- hydrophilic
- oleophobic
- 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
Images
Classifications
-
- 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
-
- 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
- B01D67/0039—Inorganic membrane manufacture
- B01D67/0041—Inorganic membrane manufacture by agglomeration of particles in the dry state
-
- 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
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- 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
- B01D71/024—Oxides
- B01D71/027—Silicium oxide
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/02—Hydrophilization
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/39—Electrospinning
-
- 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
Abstract
The application discloses super hydrophilic and super oleophobic carbon nanofiber membrane under water and preparation method thereof includes the following steps: firstly, sequentially adding a silicon source and a spinning polymer into a solvent containing a catalyst, fully stirring, and obtaining a stable spinning solution after the polymer is completely dissolved; then preparing a composite precursor nanofiber membrane by an electrostatic spinning method; carrying out heat treatment on the composite precursor nanofiber membrane; then carbonizing under the protection of high-purity nitrogen to prepare a nascent carbon nanofiber membrane; and finally, rapidly calcining the nascent carbon nanofiber membrane in the air atmosphere to obtain the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane. The preparation method is simple and easy to implement, efficient, pollution-free and easy to scale, and the obtained carbon nanofiber membrane has super-hydrophilicity and super-lipophobicity in water and can be used for rapid purification treatment of oil-in-water oil-water mixtures.
Description
Technical Field
The application belongs to the technical field of carbon nanofiber membrane preparation, and particularly relates to a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and a preparation method thereof.
Background
The harm of oil pollution of the water body is serious and frequent, however, the existing state of the oil pollutants in the water body is complex and the nature of the oily sewage is various, and the conventional oily sewage treatment technology is difficult to efficiently remove micro oil drops in the water body. The activated carbon material is often used for adsorbing and separating organic pollutants in water due to the characteristics of large specific surface area, good chemical/thermal stability and the like, but the activated carbon has the problems of difficult recovery and low treatment efficiency. The membrane separation method water treatment technology has the advantages of high efficiency, no secondary pollution and the like, and becomes an important development direction of the oily sewage treatment technology, but the conventional polymer separation membrane material still has the problems of insufficient chemical stability, easy oil pollution and the like. The carbon nanofiber is a novel one-dimensional carbon material with high length-diameter ratio and diameter between that of a carbon nanotube and that of common carbon fiber, has all properties of conventional carbon materials, has the characteristics of small fiber diameter, small membrane pore size and high porosity, and has wide application prospect in the technical field of membrane separation method water treatment.
In recent years, researchers have made certain research works on the research of Carbon nanofiber membranes for oil-water separation, and the application research of Carbon nanofiber membranes in the field of oil-water separation is reported in the documents "high efficiency and flexible electron spinning Carbon-silica nanofiber membranes for ultra-high performance-drive oil-water separation, ACS Applied Materials & Interfaces 2014, 6, 9393-. However, since the conventional carbon materials mostly have hydrophobic and oleophilic properties, the carbon nanofiber membranes reported in the above papers are all hydrophobic and oleophilic membrane materials, which results in that water is difficult to permeate the membrane materials and the membrane surface is very easily polluted by oil, and the oily sewage, especially the oil-in-water emulsified oil-water mixture, cannot be effectively treated, which limits the application of the carbon nanofiber membrane materials in the field of oily sewage purification to a certain extent. Therefore, the improvement of the hydrophilicity and the lipophobicity of the carbon nanofiber membrane has important significance for realizing the oily sewage treatment application of the carbon nanofiber membrane.
Literature "Hierarchical TiO2 nanorod arrays/carbon nanofiber membranes for oil-in-water emulsion separation, Industrial &Engineering Chemistry Research, 2020, 59, 21097-. However, the hydrophilicity of the carbon nanofiber membrane reported in the above documents needs to be achieved by external conditions (such as electrical stimulation or light irradiation) initiation, and the hydrophilic material loaded on the surface of the membrane is easy to fall off in long-term use, thereby causing secondary pollution to the environment.
Domestic patent CN111715081A discloses a preparation method of a hydrophilic nitrogen-doped carbon nanofiber dense network. The method comprises the steps of preparing nascent carbon nanofibers by a vapor phase growth method, introducing nitrogen for nitrogen doping treatment to improve the hydrophilicity of the carbon nanofibers, and finally preparing the carbon nanofiber membrane by a vacuum filtration deposition method. However, the method has a complex process flow and is not easy to operate, the carbon nanofibers obtained by the vapor phase growth method are short in length, and although the membrane-shaped material can be obtained after suction filtration and deposition, the entanglement degree of fibers in the membrane is low, so that the structural stability of the material in a long-term use process under a complex environment is difficult to ensure.
Domestic patent CN113600033A discloses a preparation method of a phenolic-based super-hydrophilic carbon nanofiber net film. The method comprises the steps of preparing a carbon nanofiber membrane through electrostatic spinning and high-temperature carbonization, and then performing hydrophilization treatment on the obtained carbon nanofiber membrane by adopting a surface oxidation method, plasma treatment or surface coating modification method to prepare the super-hydrophilic carbon nanofiber membrane. However, the technology of this patent still needs to be modified by strong oxidizing chemicals, high-energy plasma or complex surface self-polymerization, and the process is relatively complex and costly. In addition, the existing hydrophilic modification technology of the carbon nanofiber membrane has the problem that the fibers are easily damaged, so that the overall mechanical property of the membrane material is reduced, and the use stability of the membrane is finally influenced. On the other hand, due to the oleophilic property of the carbon material, the carbon nanofiber membrane mostly shows oleophilic property under water, so that the carbon nanofiber membrane is easy to be polluted in the using process. Therefore, the underwater oleophobic modification of the carbon nanofiber membrane has important significance for improving the application performance of oily sewage purification, but related technologies are rarely reported.
Disclosure of Invention
In order to solve the problems that the existing hydrophilic carbon nanofiber membrane preparation technology is complex and high in cost, the existing hydrophilic modification method has large damage to the structure and mechanical properties of the carbon nanofiber membrane, and the existing technology is difficult to obtain an underwater super-oleophobic effect, the application provides a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and a preparation method thereof.
A preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): adding a silicon source and a spinning polymer into a solvent containing a catalyst in sequence, and fully stirring to obtain a stable spinning solution after the polymer is completely dissolved;
step (2): performing electrostatic spinning on the spinning solution obtained in the step (1) to obtain a precursor nanofiber membrane with uniform thickness;
and (3): carrying out heat treatment on the precursor nanofiber membrane obtained in the step (2);
and (4): carbonizing the precursor nanofiber membrane subjected to heat treatment in the step (3) to obtain a nascent carbon nanofiber membrane;
and (5): and (4) carrying out rapid calcination treatment on the nascent carbon nanofiber membrane obtained in the step (4) in an air atmosphere to obtain the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane.
Further, the silicon source in the step (1) is one or a mixture of two of tetraethoxysilane liquid and silicon dioxide nano-particles, wherein the particle size of the silicon dioxide nano-particles is 7-40 nm.
Further, the spinning polymer in the step (1) is polyacrylonitrile or polyacrylonitrile in a mass ratio of 3: 2 with a thermosetting phenolic resin.
Further, the mass fraction of the spinning polymer in the spinning solution in the step (1) is 5-12%; the addition amount of the silicon source is 15-30% of the total mass of the spinning polymer.
Further, the solvent in the step (1) is one or a mixture of more of N, N-dimethylformamide, N-dimethylacetamide and dimethyl sulfoxide, the catalyst is glacial acetic acid, and the addition amount of the glacial acetic acid is 0-6.25% of the volume of the solvent.
Further, the electrostatic spinning parameters in the step (2) are as follows: spinning voltage is 25kV, receiving distance is 20cm, spinning solution perfusion speed is 0.5-1.5mL/h, ambient temperature is 20-30 ℃, and ambient humidity is 40-50%; the thickness of the precursor nanofiber membrane is controlled to be 10-100 mu m. .
Further, the heat treatment in the step (3) comprises single-temperature-stage heat treatment or double-temperature-stage heat treatment; the single-temperature-section heat treatment comprises the following steps: firstly, heating the temperature of a blast oven to 240 ℃, then placing the precursor nanofiber membrane on a metal mesh support, placing the metal mesh support in the blast oven for pre-oxidation for 120min, taking out the metal mesh support, and naturally cooling to room temperature; the double-temperature-section treatment comprises the following steps: the temperature of a blast oven is firstly raised to 150 ℃, then the precursor nanofiber membrane is placed on a metal mesh support frame and is put into the blast oven for pre-oxidation for 30min, then the temperature of the blast oven is raised to 240 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 120min, and then the membrane is taken out and is naturally cooled to the room temperature.
Further, the carbonization treatment process in the step (4) is as follows: and (3) placing the precursor nanofiber membrane subjected to heat treatment in a vacuum tube furnace in a free state, heating to 800-class 1000 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature.
Further, the step (5) of performing the flash calcination treatment in the air atmosphere comprises: placing the nascent carbon nanofiber membrane in a crucible, placing the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, preserving heat for 6-30min, and finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane prepared by any one of the methods is provided.
Compared with the prior art, the beneficial effect of this application lies in:
1. the silicon dioxide component is introduced into the carbon nanofiber, so that the flexibility of the carbon nanofiber membrane is improved;
2. according to the method, the carbon nanofiber membrane containing the silicon dioxide component is subjected to rapid calcination treatment in the air, and the treatment method can locally ablate a carbon layer on the surface of the fiber, so that the silicon dioxide component is locally exposed to form high-density hydrophilic sites, and the carbon nanofiber membrane is super-hydrophilic; meanwhile, due to the hydration of the hydrophilic sites, an oleophobic hydration layer is formed on the surface of the carbon nanofiber, so that the contact area of oil drops and the carbon nanofiber membrane is reduced, and the carbon nanofiber membrane has underwater super-oleophobic performance;
3. the technology has small damage to the nascent carbon nanofiber membrane, and the obtained carbon nanofiber oil-water separation membrane has good structural integrity and excellent mechanical property;
4. the preparation method of the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane has the advantages of simple process, easiness in operation, no need of additional chemical reagent modification, low cost, environmental friendliness, no pollution and easiness in large-scale production.
Description of the drawings:
FIG. 1 is a schematic diagram of the superhydrophilic and underwater superoleophobic properties of a carbon nanofiber membrane of the present application;
FIG. 2 is a photograph of a dynamic water contact angle test of a superhydrophilic and underwater superoleophobic carbon nanofiber membrane of the present application;
FIG. 3 is a photograph of an underwater static oil contact angle test of an ultra-hydrophilic and underwater ultra-oleophobic carbon nanofiber membrane of the present application;
FIG. 4 is a photo of an underwater oil adhesion resistance test of the superhydrophilic and underwater superoleophobic carbon nanofiber membrane of the present application;
FIG. 5 is a photograph showing a water static contact angle test of the carbon nanofiber membrane obtained in comparative example 1;
fig. 6 is a photograph of an underwater dynamic oil contact angle test of the carbon nanofiber membrane obtained in comparative example 1.
The specific implementation mode is as follows:
the following examples will give the skilled person a more complete understanding of the present invention, but do not limit the invention in any way.
In the following examples, polyacrylonitrile (molecular weight 9 ten thousand) for preparing a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane was purchased from hong Yi plastics ltd, kunsho, where thermosetting phenol resin was a laboratory synthetic polybenzoxazine resin, and ethyl orthosilicate, silica nanoparticles (7-40 nm), N-dimethylformamide, N-dimethylacetamide, dimethyl sulfoxide, and glacial acetic acid were purchased from mclin biochemical technology ltd, shanghai; the electrostatic spinning adopts an HZ-11 type multi-nozzle electrostatic spinning machine produced by Qingdao Nuokang environmental protection science and technology Limited, and the receiving base material adopts polypropylene spun-bonded non-woven fabric with the gram weight of 10g/m 2; the contact angle test adopts an SDC-350 contact angle measuring instrument of intelligent science and technology Limited company of Chengding industries in Kunshan, wherein during the water contact angle test, a carbon nanofiber oil-water separation membrane is stretched by a tension clamp to be flat and is fixedly arranged on a horizontal test table, a microinjector is adopted to transfer 3 mu L of ultrapure water liquid drops to the surface of the carbon nanofiber oil-water separation membrane, after the water drops are stable in shape, contact angle pictures are taken and measured, and at least 5 measured results are averaged; when testing the underwater oil contact angle, firstly fixing and stretching a carbon nanofiber oil-water separation membrane by a tension clamp, horizontally immersing the carbon nanofiber oil-water separation membrane into a quartz cuvette containing deionized water, transferring 3 mu L of dichloromethane liquid drops to the surface of the carbon nanofiber oil-water separation membrane by using a micro-injector, taking a contact angle picture and measuring after the liquid drops are stable in shape, and averaging at least 5 measured results; when measuring the dynamic infiltration time of the liquid drop on the surface of the film, shooting the infiltration process of the liquid drop at the speed of 100 frames/second by adopting a high-speed camera, and then calculating the complete infiltration time according to the time required when the contact angle of the liquid drop in the shot picture is changed into 0 degree; the evaluation of the purification performance of the membrane material oily sewage is to take n-hexane as a template of an oil pollutant, mix the n-hexane and deionized water in a volume ratio of 1:9, and carry out emulsification treatment on the obtained oil-water mixture for 1h by adopting a 100W ultrasonic wave dispersing instrument to prepare the oil-in-water type emulsified oil-water mixture. The oil-water separation performance test process of the membrane material comprises the following steps: firstly, placing a separation membrane in a commercially available filtering device, adding an oil-in-water emulsified oil-water mixture into a funnel of the filtering device, keeping the liquid level height at 10cm, and calculating the membrane separation flux by measuring the volume V of filtrate collected in unit time t (t =1 min) and using a formula P = V/St, wherein S is the effective working area of the separation membrane; subsequently, a Total Organic Carbon (TOC) value C0 of the pre-separation miscella and a TOC value C1 of the post-separation filtrate were measured using a total organic carbon analyzer and were determined by the following formula: e = (C0-C1)/C0 to calculate membrane separation efficiency.
Example 1:
a preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): polyacrylonitrile is taken as a spinning polymer, tetraethoxysilane is taken as a silicon source, N-dimethylformamide is taken as a solvent, the mass fraction of the polyacrylonitrile is 12 percent (3.6 g), and the adding amount of the tetraethoxysilane is 30 percent (1.08 g) of the mass of the polyacrylonitrile; adding tetraethoxysilane into N, N-dimethylformamide (26.4 g) containing glacial acetic acid (the volume fraction is 6.25%) at room temperature, magnetically stirring for 30min, then adding polyacrylonitrile, and fully stirring the mixed solution until the polyacrylonitrile is completely dissolved to obtain a spinning solution;
step (2): adding the spinning solution obtained in the step (1) into an electrostatic spinning machine for electrostatic spinning, wherein the spinning voltage is 25kV, the receiving distance is 20cm, the ambient temperature is 25 ℃, the ambient humidity is 45%, and the spinning solution filling speed is 1mL/h, so as to prepare a precursor nanofiber membrane with uniform structure and thickness;
and (3): carrying out single-temperature-section heat treatment on the precursor nanofiber membrane obtained in the step (2): firstly, heating the temperature of a blast oven to 240 ℃, then placing the precursor nanofiber membrane on a metal mesh support, placing the metal mesh support in the blast oven for pre-oxidation for 120min, taking out the metal mesh support, and naturally cooling to room temperature;
and (4): placing the precursor nanofiber membrane subjected to heat treatment in the step (3) in a vacuum tube furnace in a free state, heating to 800 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature to prepare a nascent carbon nanofiber membrane;
and (5): placing the nascent carbon nanofiber membrane obtained in the step (4) in a crucible, putting the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, and keeping the temperature for 6 min; and finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is prepared by the method.
Example 2:
a preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): polyacrylonitrile is taken as a spinning polymer, tetraethoxysilane is taken as a silicon source, N-dimethylformamide is taken as a solvent, the mass fraction of the polyacrylonitrile is 5 percent (1.5 g), and the adding amount of the tetraethoxysilane is 30 percent (0.45 g) of the mass of the polyacrylonitrile; adding tetraethoxysilane into N, N-dimethylformamide (28.5 g) containing glacial acetic acid (the volume fraction is 6.25%) at room temperature, magnetically stirring for 30min, then adding polyacrylonitrile, and fully stirring the mixed solution until the polyacrylonitrile is completely dissolved to obtain a spinning solution;
step (2): adding the spinning solution obtained in the step (1) into an electrostatic spinning machine for electrostatic spinning, wherein the spinning voltage is 25kV, the receiving distance is 20cm, the ambient temperature is 25 ℃, the ambient humidity is 45%, and the spinning solution filling speed is 1mL/h, so as to prepare a precursor nanofiber membrane with uniform structure and thickness;
and (3): carrying out single-temperature-section heat treatment on the precursor nanofiber membrane obtained in the step (2): firstly, heating the temperature of a blast oven to 240 ℃, then placing the precursor nanofiber membrane on a metal mesh support, placing the metal mesh support in the blast oven for pre-oxidation for 120min, taking out the metal mesh support, and naturally cooling to room temperature;
and (4): placing the precursor nanofiber membrane subjected to heat treatment in the step (3) in a vacuum tube furnace in a free state, heating to 800 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature to prepare a nascent carbon nanofiber membrane;
and (5): placing the nascent carbon nanofiber membrane obtained in the step (4) in a crucible, putting the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, and preserving heat for 30 min; and finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is prepared by the method.
Example 3:
a preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): the method is characterized in that a mixture of polyacrylonitrile and thermosetting phenolic resin is used as a spinning polymer, silicon dioxide nanoparticles are used as a silicon source, N-dimethylformamide is used as a solvent, and the total mass fraction of the spinning polymer is 12% (3.6 g), wherein the mass ratio of the polyacrylonitrile to the thermosetting phenolic resin is 3: 2, namely the mass fraction of polyacrylonitrile is 7.2 percent (2.16 g), the mass fraction of thermosetting phenolic resin is 4.8 percent (1.44 g), and the adding amount of silicon dioxide nano particles is 15 percent (0.54 g) of the total mass of polyacrylonitrile and thermosetting phenolic resin; adding silicon dioxide nanoparticles into N, N-dimethylformamide at room temperature, performing ultrasonic dispersion treatment for 1h at the power of 200W, then adding polyacrylonitrile and thermosetting phenolic resin, and fully stirring the mixed solution until all spinning polymers are completely dissolved to obtain a spinning solution;
step (2): adding the spinning solution obtained in the step (1) into an electrostatic spinning machine for electrostatic spinning, wherein the spinning voltage is 25kV, the receiving distance is 20cm, the ambient temperature is 25 ℃, the ambient humidity is 45%, and the spinning solution filling speed is 0.5mL/h, so as to prepare a precursor nanofiber membrane with uniform structure and thickness;
and (3): carrying out double-temperature-section heat treatment on the precursor nanofiber membrane obtained in the step (2): firstly, heating the temperature of a blast oven to 150 ℃, then placing a precursor nanofiber membrane on a metal mesh support frame, placing the precursor nanofiber membrane in the blast oven for pre-oxidation for 30min, then heating the temperature of the blast oven to 240 ℃ at the heating rate of 5 ℃/min, preserving the heat for 120min, and then taking out the membrane and naturally cooling to the room temperature;
and (4): placing the precursor nanofiber membrane subjected to heat treatment in the step (3) in a vacuum tube furnace in a free state, heating to 1000 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature to prepare a nascent carbon nanofiber membrane;
and (5): placing the nascent carbon nanofiber membrane obtained in the step (4) in a crucible, putting the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, and preserving heat for 30 min; and finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is prepared by the method.
Example 4:
a preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): polyacrylonitrile is used as a spinning polymer, silicon dioxide nanoparticles are used as a silicon source, a mixture of dimethyl sulfoxide and N, N-dimethylacetamide in equal mass is used as a solvent, the mass fraction of polyacrylonitrile is 7% (2.1 g), and the addition amount of the silicon dioxide nanoparticles is 30% (0.63 g) of the mass of polyacrylonitrile; adding silicon dioxide nanoparticles into a mixture of dimethyl sulfoxide (13.95 g) and N, N-dimethylacetamide (13.95 g) at room temperature, performing ultrasonic dispersion treatment for 1h at 200W power, adding polyacrylonitrile, and fully stirring the mixed solution until the polyacrylonitrile is completely dissolved to obtain a spinning solution;
step (2): adding the spinning solution obtained in the step (1) into an electrostatic spinning machine for electrostatic spinning, wherein the spinning voltage is 25kV, the receiving distance is 20cm, the ambient temperature is 25 ℃, the ambient humidity is 45%, and the spinning solution filling speed is 0.5mL/h, so as to prepare a precursor nanofiber membrane with uniform structure and thickness;
and (3): carrying out single-temperature-section heat treatment on the precursor nanofiber membrane obtained in the step (2): firstly, heating the temperature of a blast oven to 240 ℃, then placing the precursor nanofiber membrane on a metal mesh support, placing the metal mesh support in the blast oven for pre-oxidation for 120min, taking out the metal mesh support, and naturally cooling the metal mesh support to room temperature;
and (4): placing the precursor nanofiber membrane subjected to heat treatment in the step (3) in a vacuum tube furnace in a free state, heating to 850 ℃ at 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature to prepare a nascent carbon nanofiber membrane;
and (5): and (4) placing the nascent carbon nanofiber membrane obtained in the step (4) in a crucible, placing the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, and preserving heat for 10 min. And finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is prepared by the method.
Example 5:
a preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane comprises the following specific steps:
step (1): the method is characterized in that a mixture of polyacrylonitrile and thermosetting phenolic resin is used as a spinning polymer, silicon dioxide nanoparticles are used as a silicon source, an equal mass mixture of N, N-dimethylformamide and dimethyl sulfoxide is used as a solvent, the total mass fraction of the spinning polymer is 10% (3.0 g), wherein the mass ratio of polyacrylonitrile to thermosetting phenolic resin is 3: 2, namely the mass fraction of polyacrylonitrile is 6 percent (1.8 g), the mass fraction of thermosetting phenolic resin is 4 percent (1.2 g), and the adding amount of silica nano-particles is 19 percent (0.57 g) of the total mass of the polyacrylonitrile and the thermosetting phenolic resin; adding silicon dioxide nanoparticles into a mixture of N, N-dimethylformamide (13.5 g) and dimethyl sulfoxide (13.5 g) at room temperature, performing ultrasonic dispersion treatment, adding polyacrylonitrile and thermosetting phenolic resin, and fully stirring the mixed solution until all spinning polymers are completely dissolved to obtain a spinning solution;
step (2): adding the spinning solution obtained in the step (1) into an electrostatic spinning machine for electrostatic spinning, wherein the spinning voltage is 25kV, the receiving distance is 20cm, the environmental temperature is 25 ℃, the environmental humidity is 45%, and the spinning solution filling speed is 1.5mL/h, so as to prepare a precursor nanofiber membrane with a uniform structure and thickness;
and (3): carrying out double-temperature-section heat treatment on the precursor nanofiber membrane obtained in the step (2): firstly, heating the temperature of a blast oven to 150 ℃, then placing a precursor nanofiber membrane on a metal mesh support frame, placing the precursor nanofiber membrane in the blast oven for pre-oxidation for 30min, then heating the temperature of the blast oven to 240 ℃ at the heating rate of 5 ℃/min, preserving the heat for 120min, then taking out the membrane, and naturally cooling to room temperature;
and (4): placing the precursor nanofiber membrane subjected to heat treatment in the step (3) in a vacuum tube furnace in a free state, heating to 950 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen and keeping for 120min, wherein the flow rate of the high-purity nitrogen is 2mL/min and the gas outlet valve of the tube furnace is kept half open, and finally naturally cooling to room temperature to prepare a nascent carbon nanofiber membrane;
and (5): placing the nascent carbon nanofiber membrane obtained in the step (4) into a dry pot, placing the dry pot into a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, and preserving heat for 20 min; and finally, naturally cooling to room temperature.
The super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is prepared by the method.
The oil-water selective wettability of the superhydrophilic and underwater superoleophobic carbon nanofiber membranes prepared in the above examples was evaluated. The result shows that, for example, as shown in fig. 1, 3 μ L of water droplets can rapidly infiltrate the surfaces of the carbon nanofiber oil-water separation membranes prepared in all the examples, and the static water contact angles of all the carbon nanofiber membranes can reach 0 °, the underwater oil contact angles are all larger than 150 ° (as shown in fig. 2), and the carbon nanofiber membranes have good oil adhesion resistance (as shown in fig. 3), which indicates that the carbon nanofiber membranes obtained by the preparation method provided by the present application have super-hydrophilic/underwater super-oleophobic properties. In addition, an oil-water separation performance test of the membrane material shows that the separation efficiency of the obtained carbon nanofiber membrane on an oil-in-water type oil-water mixture can reach more than 95%, and the water flux can reach more than 2000Lm-2 h-1.
Comparative example 1:
to further illustrate the beneficial effects of adding a silicon source into the spinning solution in the present application technology, polyacrylonitrile is used as the spinning polymer, the carbon nanofiber membrane is prepared by the same method as the steps (2) - (5) in example 1 without adding a silicon source, and the water contact angle and the underwater oil contact angle of the carbon nanofiber membrane are tested. As can be seen from FIG. 4, the water contact angle can reach more than 145 degrees, and the water-repellent coating is hydrophobic; fig. 5 is a photograph of a contact angle test of the underwater dynamic oil of the carbon nanofiber membrane obtained in the present comparative example, which shows that oil drops (3 μ L of dichloromethane) can rapidly infiltrate the surface of the membrane, indicating that the carbon nanofiber membrane obtained in the present comparative example is oleophilic under water, and water is difficult to permeate through the carbon nanofiber membrane wetted with oil, so the carbon nanofiber membrane obtained in the present comparative example cannot be applied to filtration and separation of an oil-in-water oil-water mixture.
Comparative example 2:
to further illustrate the important role of the rapid calcination process in air in step (5) of the technology of the present application in the preparation of superhydrophilic and underwater superoleophobic carbon nanofiber membranes. This comparative example prepared a carbon nanofiber membrane in the same manner as in steps (1) to (4) of example 1. Tests show that the silicon dioxide-containing carbon nanofiber membrane obtained without the rapid calcination process in the step (5) has a water contact angle of more than 140 degrees and an underwater oil contact angle of 0 degrees, is hydrophobic and oleophilic under water, and water still hardly penetrates through the carbon nanofiber membrane wetted by oil. Therefore, the carbon nanofiber membrane obtained in the comparative example cannot be applied to filtration and separation of an oil-in-water type oil-water mixture.
Claims (10)
1. A preparation method of a super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane is characterized by comprising the following steps:
step (1): adding a silicon source and a spinning polymer into a solvent containing a catalyst in sequence, and fully stirring to obtain a stable spinning solution after the polymer is completely dissolved;
step (2): performing electrostatic spinning on the spinning solution obtained in the step (1) to obtain a precursor nanofiber membrane with uniform thickness;
and (3): carrying out heat treatment on the precursor nanofiber membrane obtained in the step (2);
and (4): carbonizing the precursor nanofiber membrane subjected to heat treatment in the step (3) to obtain a nascent carbon nanofiber membrane;
and (5): and (4) carrying out rapid calcination treatment on the nascent carbon nanofiber membrane obtained in the step (4) in an air atmosphere to obtain the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane.
2. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the silicon source in the step (1) is one or a mixture of two of tetraethoxysilane liquid and silicon dioxide nano-particles, wherein the particle size range of the silicon dioxide nano-particles is 7-40 nm.
3. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane as claimed in claim 1, characterized in that: the spinning polymer in the step (1) is polyacrylonitrile or polyacrylonitrile with the mass ratio of 3: 2 with a thermosetting phenolic resin.
4. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the mass fraction of the spinning polymer in the spinning solution in the step (1) is 5-12%; the addition amount of the silicon source is 15-30% of the total mass of the spinning polymer.
5. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the solvent in the step (1) is one or a mixture of N, N-dimethylformamide, N-dimethylacetamide and dimethyl sulfoxide, the catalyst is glacial acetic acid, and the adding amount of the glacial acetic acid is 0-6.25% of the volume of the solvent.
6. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the electrostatic spinning process parameters in the step (2) are as follows: spinning voltage is 25kV, receiving distance is 20cm, spinning solution perfusion speed is 0.5-1.5mL/h, ambient temperature is 20-30 ℃, and ambient humidity is 40-50%; the thickness of the precursor nanofiber membrane is controlled to be 10-100 mu m.
7. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the heat treatment in the step (3) is one of single-temperature-section heat treatment or double-temperature-section heat treatment; the single-temperature section heat treatment mode is as follows: firstly, heating the temperature of a blast oven to 240 ℃, then placing the precursor nanofiber membrane on a metal mesh support, placing the metal mesh support in the blast oven for pre-oxidation for 120min, taking out the metal mesh support, and naturally cooling to room temperature; the double-temperature section treatment mode is as follows: the temperature of a blast oven is firstly raised to 150 ℃, then the precursor nanofiber membrane is placed on a metal mesh support frame and is pre-oxidized in the blast oven for 30min, then the temperature of the blast oven is raised to 240 ℃ at the heating rate of 5 ℃/min, the temperature is preserved for 120min, and then the membrane is taken out and is naturally cooled to the room temperature.
8. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: the carbonization treatment process in the step (4) comprises the following steps: and (3) placing the precursor nanofiber membrane subjected to heat treatment in a vacuum tube furnace in a free state, heating to 800-class 1000 ℃ at a speed of 5 ℃/min under the protection of high-purity nitrogen, keeping the temperature for 120min, keeping the flow of the high-purity nitrogen at 2mL/min, keeping a gas outlet valve of the tube furnace half open, and naturally cooling to room temperature.
9. The method for preparing the super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane according to claim 1, characterized in that: and (5) the step of carrying out rapid calcination treatment in the air atmosphere comprises the steps of placing the nascent carbon nanofiber membrane in a crucible, placing the crucible in a muffle furnace, heating to 500 ℃ at a heating rate of 15 ℃/min, keeping the temperature for 6-30min, and finally naturally cooling to room temperature.
10. A superhydrophilic and underwater superoleophobic carbon nanofiber membrane made by the method of any of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210604756.1A CN114749039B (en) | 2022-05-31 | 2022-05-31 | Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210604756.1A CN114749039B (en) | 2022-05-31 | 2022-05-31 | Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114749039A true CN114749039A (en) | 2022-07-15 |
| CN114749039B CN114749039B (en) | 2022-12-27 |
Family
ID=82336280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210604756.1A Active CN114749039B (en) | 2022-05-31 | 2022-05-31 | Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114749039B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114984777A (en) * | 2022-08-04 | 2022-09-02 | 常熟东南塑料有限公司 | Preparation method and application of phenolic resin carbon film |
| CN115337791A (en) * | 2022-09-02 | 2022-11-15 | 万华化学集团股份有限公司 | Hollow fiber porous membrane and preparation method and application thereof |
| CN115519859A (en) * | 2022-09-30 | 2022-12-27 | 南通大学 | Carbon nanofiber-based breathable gas-defense garment fabric and preparation method thereof |
| CN115337791B (en) * | 2022-09-02 | 2024-05-03 | 万华化学集团股份有限公司 | Hollow fiber porous membrane and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160129400A1 (en) * | 2010-06-14 | 2016-05-12 | The Regents Of The University Of Michigan | Superhydrophilic and oleophobic porous materials and methods for making and using the same |
| CN107583470A (en) * | 2017-09-18 | 2018-01-16 | 上海大学 | Super hydrophilic and underwater superoleophobic water-oil separationg film and preparation method thereof |
| CN110756062A (en) * | 2019-10-14 | 2020-02-07 | 淮阴师范学院 | Super-hydrophilic underwater super-hydrophobic oil separation membrane and preparation method thereof |
-
2022
- 2022-05-31 CN CN202210604756.1A patent/CN114749039B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20160129400A1 (en) * | 2010-06-14 | 2016-05-12 | The Regents Of The University Of Michigan | Superhydrophilic and oleophobic porous materials and methods for making and using the same |
| CN107583470A (en) * | 2017-09-18 | 2018-01-16 | 上海大学 | Super hydrophilic and underwater superoleophobic water-oil separationg film and preparation method thereof |
| CN110756062A (en) * | 2019-10-14 | 2020-02-07 | 淮阴师范学院 | Super-hydrophilic underwater super-hydrophobic oil separation membrane and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| SHAN YANG等: "Superwetting hierarchical porous silica", 《NANOSCALE》 * |
| 张继超: "超润湿性纳米纤维基油水乳液分离膜的结构设计及其性能研究", 《中国博士学位论文全文数据库（电子期刊）工程科技Ⅰ辑》 * |
| 葛建龙: "乳化含油污水净化用静电纺纳米纤维膜的结构设计及性能研究", 《中国博士学位论文全文数据库（电子期刊）工程科技Ⅰ辑》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114984777A (en) * | 2022-08-04 | 2022-09-02 | 常熟东南塑料有限公司 | Preparation method and application of phenolic resin carbon film |
| CN115337791A (en) * | 2022-09-02 | 2022-11-15 | 万华化学集团股份有限公司 | Hollow fiber porous membrane and preparation method and application thereof |
| CN115337791B (en) * | 2022-09-02 | 2024-05-03 | 万华化学集团股份有限公司 | Hollow fiber porous membrane and preparation method and application thereof |
| CN115519859A (en) * | 2022-09-30 | 2022-12-27 | 南通大学 | Carbon nanofiber-based breathable gas-defense garment fabric and preparation method thereof |
| WO2024066669A1 (en) * | 2022-09-30 | 2024-04-04 | 南通大学 | Carbon nanofiber-based breathable hazmat suit fabric, and preparation method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114749039B (en) | 2022-12-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114749039B (en) | Super-hydrophilic and underwater super-oleophobic carbon nanofiber membrane and preparation method thereof | |
| CN110756062B (en) | Super-hydrophilic underwater super-hydrophobic oil separation membrane and preparation method thereof | |
| Zhang et al. | A heterostructured PPy/ZnO layer assembled on a PAN nanofibrous membrane with robust visible-light-induced self-cleaning properties for highly efficient water purification with fast separation flux | |
| CN109012237B (en) | Super-hydrophobic super-oleophylic nanofiber membrane for oil-water mixture separation and preparation method thereof | |
| CN110755887B (en) | Preparation method and application of super-infiltrated Janus material | |
| Cao et al. | Construction of Polytetrafluoroethylene nanofiber membrane via continuous electrospinning/electrospraying strategy for oil-water separation and demulsification | |
| CN109731479B (en) | Preparation method of super-hydrophobic nanofiber membrane and super-hydrophobic nanofiber membrane | |
| CN104722215B (en) | Preparation method of carbon dioxide separation film based on graphene material | |
| CN110368718B (en) | Three-dimensional printed super-hydrophilic and underwater super-oleophobic net film and preparation method thereof | |
| Qiao et al. | Al-DTPA microfiber assisted formwork construction technology for high-performance SiC membrane preparation | |
| CN108246125B (en) | High-anti-pollution internal support polyvinylidene fluoride hollow fiber membrane and preparation method thereof | |
| CN111604032B (en) | Janus nitrogen-doped carbon nanofiber film and preparation method and application thereof | |
| Li et al. | Electrospun fibrous PTFE supported ZnO for oil–water separation | |
| Fan et al. | Electro-blown spun PS/PAN fibrous membrane for highly efficient oil/water separation | |
| CN106283894B (en) | A kind of graphene oxide is modified filter paper and preparation method and application | |
| CN107930415B (en) | Preparation method of hollow fiber ceramic membrane with petal-shaped cross section and surface loaded with catalyst | |
| KR101713858B1 (en) | Hydrophobic alumina hollow fiber membrane for absorption of carbon dioxide and preparation method thereof | |
| Pei et al. | Preparation of superhydrophilic polyimide fibrous membranes by electrostatic spinning fabrication for the efficient separation of oil-in-water emulsions | |
| CN112755805B (en) | Underwater super-oleophobic two-dimensional nanoscale mica sheet oil-water separation membrane and preparation method and application thereof | |
| CN113308753A (en) | High-temperature adsorbable porous polyimide nanofiber and preparation method and application thereof | |
| CN108771981A (en) | Graphene composite material and its preparation method and application, graphene-carbon nano-fiber film and preparation method thereof | |
| CN112999895A (en) | Preparation method of polyvinylidene fluoride hydrophilic stretched film | |
| CN110055622B (en) | Preparation method of hollow-structure porous carbon nanofiber | |
| CN115418795B (en) | Janus type micro-nano composite fiber membrane with single-sided superhydrophobic and single-sided superhydrophilic properties and preparation method thereof | |
| CN114247312B (en) | Composite fiber membrane with asymmetric wettability, preparation method thereof and application thereof in oil-water separation |
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 |