Preparation method and application of ultraviolet curing electrostatic spinning membrane for adsorbing copper ions

Abstract

The invention discloses a preparation method and application of an ultraviolet curing electrostatic spinning membrane for adsorbing copper ions, a DMF (Dimethyl Formamide) solution dissolved with acrylic acid, acrylamide, ethylene glycol dimethacrylate, benzoin dimethyl ether and polyacrylonitrile is blended into fibers through an electrostatic spinning method, and then a cross-linked structure is generated through ultraviolet curing. The polymer adsorbent can be prevented from being dissolved in water. The fibrous adsorbent prepared by combining electrostatic spinning and ultraviolet curing technologies has the advantages of simple preparation process, good adsorption effect and the like, can be used for adsorbing copper ions in sewage, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of membrane materials, and specifically relates to the preparation of an electrospun fiber membrane and its application in the adsorption of copper ions in wastewater. Background Art

[0002] With the rapid rise of industry, the amount of copper ion-containing wastewater generated from the mining and smelting of copper-zinc ores, metal processing, machinery manufacturing, and steel production has increased. Copper ion-containing wastewater, as a major environmental pollutant, needs to be effectively treated. Physical methods are widely used due to their advantages such as economy, high efficiency, environmental friendliness, and renewability. As a physical method, the adsorption method is considered to have broad application prospects because of its high efficiency, low cost, and simple and practical applicability in the treatment of dye wastewater.

[0003] The nanofiber materials prepared by electrospinning technology have a fast adsorption rate, good stability, convenient use, and are easy to recycle. The ultraviolet curing technology has an extremely short reaction time, simple experimental operation, can control the reaction process at any time, and saves energy. It is a very green and environmentally friendly method. In the present invention, a DMF solution of acrylic acid, acrylamide, ethylene glycol dimethacrylate, benzoin dimethyl ether and polyacrylonitrile is electrospun into fibers, and then crosslinked structures are generated by ultraviolet lamp curing. The prepared electrospun fiber membrane contains a large number of carboxyl groups and amino groups and has a good adsorption effect on copper ions. The fibrous adsorbent prepared by combining electrospinning and ultraviolet curing technologies in the present invention has the advantages of simple preparation process and good adsorption property. Summary of the Invention

[0004] Acrylic acid and acrylamide contain amino and carboxyl groups, and have a good adsorption effect after polymerization into polymers. However, their linear polymers will gradually dissolve in water as adsorbents. If they are made into crosslinked network polymers, they will not dissolve in water. In this study, monomers containing carboxyl and amino groups are first dissolved in a homogeneous solution of PAN in DMF, and then a photoinitiator is added. After spinning into a fiber membrane, a crosslinked structure is obtained by ultraviolet lamp irradiation and used to adsorb copper ions.

[0005] The present invention is achieved through the following technical solutions: In a first aspect of the present invention, a method for preparing an ultraviolet-cured electrospun membrane for adsorbing copper ions is provided, and the following steps are as follows: Dissolve PAN in an organic solvent N,N-dimethylformamide and stir until a homogeneous transparent solution is formed; Add acrylic acid, acrylamide, ethylene glycol dimethacrylate, and benzoin dimethyl ether to the above solution to obtain a uniform mixture; Electrospin the above mixture and irradiate it with an ultraviolet lamp to obtain an acrylic acid-acrylamide-ethylene glycol dimethacrylate-polyacrylonitrile electrospun membrane.

[0006] Furthermore, the mass concentration of polyacrylonitrile is 5 - 30%, the mass ratio of acrylamide to ethylene glycol dimethacrylate is 5:2 - 1:1, the mass ratio of acrylic acid to acrylamide is 3:1 - 3:2, the mass concentration of acrylic acid, acrylamide and ethylene glycol dimethacrylate is 10% - 20%, and the mass ratio of benzoin dimethyl ether to acrylic acid, acrylamide and ethylene glycol dimethacrylate is 3:100 - 8:100.

[0007] Furthermore, the electrospinning parameters are set as follows: the voltage connected to the needle is 10 - 20 kV, the voltage connected to the roller is -10 - 0 kV, the feeding speed is 0.5 - 2 mL / h, the distance from the syringe needle to the aluminum foil of the receiver is 5 - 20 cm, the humidity is maintained at 10 - 30%, and the operating temperature is 10 - 30 °C.

[0008] Furthermore, the wavelength of the ultraviolet lamp is 315 - 400 nm, the power is 30 - 20000 W, the distance between the ultraviolet lamp and the electrospun fiber membrane is 5 - 30 cm, the irradiation frequency is 1 - 10 times per hour, and each irradiation lasts for 1 to 5 minutes.

[0009] In the second aspect of the present invention, an application of the above-mentioned electrospun membrane in adsorbing copper ions is provided, and the steps are as follows: Place the adsorbent in a copper ion solution for adsorption. Conduct an adsorption experiment on a shaker, read the copper ion concentration through an atomic absorption spectrometer, and calculate its adsorption effect.

[0010] Furthermore, the copper ion solution for adsorption is one or more mixed solutions of copper nitrate, copper sulfate, copper chloride, copper acetate, copper hydroxide solution or copper ions in industrial wastewater.

[0011] Furthermore, the copper ion concentration is 10 - 1000 mg / L.

[0012] Furthermore, the shaker speed is 50 - 200 rpm.

[0013] Furthermore, the adsorption temperature is 5 - 35 °C, and the adsorption time is 12 - 24 h.

[0014] The beneficial effects of the present invention are as follows: By using electrospinning and ultraviolet light polymerization method, first, a DMF solution dissolved with acrylic acid, acrylamide, ethylene glycol dimethacrylate, dimethoxybenzil and polyacrylonitrile is electrospun into fibers, and then cured by an ultraviolet lamp to generate a crosslinked structure. Since the crosslinked structure polymer can avoid the dissolution of the product in water, the unstable adsorption effect caused by it is avoided. This material contains a large number of carboxyl groups and amino groups and has good adsorption performance for copper ions. The fibrous adsorbent prepared by combining electrospinning and ultraviolet curing technology in the present invention has the advantages of simple preparation process and good adsorption property, and has certain application prospects in removing copper ions from industrial wastewater. Description of the Drawings

[0015] Figure 1 It is a scanning electron microscope (SEM) picture of the prepared electrospun membrane. Detailed Embodiments

[0016] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0017] Example 1 Dissolve 6.1 g of PAN in 8 g of organic solvent N,N-dimethylformamide and stir until a homogeneous transparent solution is formed; add 1.7 g of acrylic acid, 1.5 g of acrylamide, 1.4 g of ethylene glycol dimethacrylate, and 0.05 g of dimethoxybenzil to the above solution and stir to obtain a uniform mixture; electrospin the above mixture and irradiate it with a 50-watt 365-nm ultraviolet lamp for 1 minute every 1 hour to obtain an acrylic acid-acrylamide-ethylene glycol dimethacrylate-polyacrylonitrile electrospun membrane.

[0018] Example 2 Dissolve 5.8 g of PAN in 8.2 g of organic solvent N,N-dimethylformamide and stir until a homogeneous transparent solution is formed; add 1.6 g of acrylic acid, 1.5 g of acrylamide, 1.5 g of ethylene glycol dimethacrylate, and 0.06 g of dimethoxybenzil to the above solution and stir to obtain a uniform mixture; electrospin the above mixture and irradiate it with a 50-watt 365-nm ultraviolet lamp for 1 minute every 1 hour to obtain an acrylic acid-acrylamide-ethylene glycol dimethacrylate-polyacrylonitrile electrospun membrane.

[0019] Example 3 To study the adsorption performance of the above embodiments of the present invention, 0.1 g of the electrospun membranes of Examples 1 and 2 were respectively placed in 50 ml of an aqueous copper nitrate solution with a concentration of 50 mg / L. After adsorption for 24 h, the equilibrium concentration of copper ions was measured using an atomic absorption spectrometer, and the equilibrium adsorption capacity of the polyacrylonitrile electrospun composite fiber membrane was calculated using the following formula; q e =(C o -C e )V / m. In the formula, q e (mg / g) is the equilibrium adsorption capacity; C o (mg / L) and C e (mg / L) are the initial concentration and equilibrium concentration of the solution, respectively; m (g) is the mass of the adsorbent; V (L) is the volume of the solution.

[0020] The adsorption results showed that the adsorption capacity of the polyacrylonitrile electrospun composite fiber membrane prepared in Example 1 for copper ions in a 50 mg / L aqueous copper nitrate solution was 184.3 mg / g, and the adsorption capacity of the polyacrylonitrile electrospun composite fiber membrane prepared in Example 2 for copper ions in a 50 mg / L aqueous copper nitrate solution was 187.6 mg / g.

[0021] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a UV-curable electrospinning membrane for adsorbing copper ions, characterized in that: The method comprises the following steps: dissolving PAN in an organic solvent N,N-dimethylformamide and stirring until a homogeneous transparent solution is formed; adding acrylic acid, acrylamide, ethylene glycol dimethacrylate and benzoin dimethyl ether to the solution to obtain a uniform mixed solution, and electrospinning the mixed solution into fibers. Using an ultraviolet lamp to irradiate the electrospun fibers, an acrylic acid-acrylamide-ethylene glycol dimethacrylate-polyacrylonitrile electrospinning membrane is obtained.

2. The method for preparing a UV-curable electrospinning membrane for adsorbing copper ions according to claim 1, characterized in that: The relative molecular mass of polyacrylonitrile is 65000-100000, the mass concentration of polyacrylonitrile is 5-30%, the mass ratio of acrylamide to ethylene glycol dimethacrylate is 5:2-1:1, the mass ratio of acrylic acid to acrylamide is 3:1-3:2, the mass concentration of acrylic acid, acrylamide and ethylene glycol dimethacrylate is 10%-20%, and the mass ratio of benzoin dimethyl ether to acrylic acid, acrylamide and ethylene glycol dimethacrylate is 1:100-8:

100.

3. The method for preparing a UV-curable electrospinning membrane for adsorbing copper ions according to claim 1, characterized in that: The electrospinning parameters were set as follows: voltage connected to the needle 10-20 kV, voltage connected to the roller -10-0 kV, delivery speed 0.5-2 mL / h, distance from syringe needle to receiver foil 5-20 cm, humidity maintained at 10-30%, and operating temperature 10-30 °C.

4. The method for preparing a UV-curable electrospinning membrane for adsorbing copper ions according to claim 1, characterized in that: The wavelength of the ultraviolet lamp is 315-400nm, the power is 30-20000W, the distance between the ultraviolet lamp and the electrospinning fiber membrane is 5-30cm, the irradiation frequency is 1-10 times per hour, and each time lasts 1-5 minutes.

5. Use of the electrospinning membrane according to claim 1 in adsorbing copper ions.

6. The use according to claim 5, characterized in that: The copper ion solution used for adsorption is one or more mixed solutions of copper nitrate, copper sulfate, copper chloride, copper acetate, copper hydroxide solution or copper ions in industrial wastewater.

7. The use according to claim 5, characterized in that: The concentration of copper ions is 10-1000 mg / L.

8. The use according to claim 5, characterized in that: The shaking speed is 50-200rpm, the adsorption temperature is 5-35℃, and the adsorption time is 12-24h.

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