Biomass hydrogel-based adsorption material and preparation method and application thereof

Abstract

The present application relates to a kind of biomass hydrogel-based adsorption material and its preparation method and application, belong to new material technical field.The biomass hydrogel-based adsorption material of the present application is three-layer structure, from top to bottom in turn: biological hydrogel fiber network layer, intermediate skeleton layer and biological hydrogel fiber network layer;The biological hydrogel fiber network layer is made using solution blowing method and photo-crosslinking technology;The intermediate skeleton layer is made using spun-bond method process;The biological hydrogel fiber network layer and the intermediate skeleton layer are compounded by airflow puncture process.The present application utilizes solution blowing spinning method, photo-crosslinking technology, spun-bond method and airflow puncture method to prepare biomass hydrogel-based adsorption material, by the mutual cooperation of interlayer, finally makes that biomass hydrogel-based adsorption material has excellent adsorption performance, good mechanical property, can be used for wastewater treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new materials, in particular to a biomass hydrogel-based adsorption material and a preparation method and application thereof. BACKGROUND

[0002] With the development of diversified demand in the clothing industry, the market demand for commercial dyes has increased and diversified, with more than 100,000 types, and the total consumption of dyes in the global textile industry exceeds 10,000 tons per year, and about 100 tons of dyes are discharged into rivers every year. In addition, many dyes threaten aquatic organisms and human health due to their toxicity and carcinogenicity, and finding an eco-friendly adsorbent with good cost-effectiveness to replace commercial activated carbon has become a research hotspot.

[0003] Hydrogel fibers refer to hydrogels with fiber or fiber-like appearance. In addition to the characteristics of solid and fluid of hydrogels, the fiber-like appearance means that the specific surface area and aspect ratio are large. The existence of this characteristic can improve the swelling property of hydrogel fibers. By integrating nanofibers and hydrogels, the functional properties of hydrogels and the structural advantages of nanofibers are endowed.

[0004] Natural biomass materials such as keratin and cellulose are rich in functional groups such as amino and carboxyl groups in their structure. These functional groups can be used as adsorption sites for heavy metal ions and dyes, making them suitable as adsorbents. Compared with other materials, biomass adsorbents have the advantages of environmental protection, renewable use, and low cost.

[0005] Solution jet spinning is a new type of nanofiber preparation technology, which has the characteristics of high fiber collection efficiency, large-scale preparation, high spinning efficiency, and irregular deposition. Compared with electrospinning technology, the nanofibers prepared by solution jet spinning have higher specific surface area, less restriction on polymer solution, simple equipment, low cost, high production efficiency, and are suitable for natural and synthetic polymers, with relatively high safety.

[0006] Currently, there have been some researches on combining hydrogels with nano-structured networks. In Chinese invention patent CN113457218B, a fiber membrane prepared by electrospinning is soaked in a hydrogel to coat it, and after freezing and thawing, an electrospinning composite hydrogel material is prepared for oil-water separation material. However, the preparation cycle of this composite hydrogel material is long, the operation is complex, the safety factor is reduced, and the preparation process is not easy to scale up. In Chinese invention patent CN112062975B, modified wool keratin and PVA are mixed by electrospinning to prepare a fiber membrane, and after cross-linking, a hydrogel is prepared, which can be used for the adsorption of metal ions. However, this adsorbent is a simple nanofiber hydrogel, and the mechanical properties are relatively poor, and the service life is relatively reduced.

[0007] Therefore, it is urgent to provide a biomass hydrogel-based adsorption material with high mechanical properties, strong adsorption capacity, short preparation time and simple preparation method. SUMMARY

[0008] To solve the above technical problems, the present application provides a biomass hydrogel-based adsorption material, a preparation method thereof and an application thereof. The biomass hydrogel-based adsorption material of the present application comprises, from top to bottom, a bio-based hydrogel fiber network layer, an intermediate skeleton layer and a bio-based hydrogel fiber network layer. The upper and lower bio-based hydrogel fiber network layers are both prepared by a solution blowing method. When the solution blowing method is used for spinning, the spinning solution solute is nanocellulose and modified keratin. During the spinning and forming process, a photopolymerization crosslinking technology is used to initiate polymerization gel. The intermediate skeleton is prepared by a spunbonding method. When the spunbonding method is used, the spinning raw material is a thermoplastic polymer and a light-heat conversion material. The three-layer composite adsorption material is prepared by a airflow puncture process to composite and reinforce the three-layer fiber network.

[0009] The present application is achieved by the following technical solutions:

[0010] The first object of the present application is to provide a biomass hydrogel-based adsorption material, which has a three-layer structure and comprises, from top to bottom, a bio-based hydrogel fiber network layer, an intermediate skeleton layer and a bio-based hydrogel fiber network layer.

[0011] The bio-based hydrogel fiber network layer is prepared by a solution blowing method and a photopolymerization crosslinking technology.

[0012] The intermediate skeleton layer is prepared by a spunbonding method.

[0013] The bio-based hydrogel fiber network layer and the intermediate skeleton layer are connected by an airflow puncture process.

[0014] In an embodiment of the present application, the diameter of the hydrogel fiber in the bio-based hydrogel fiber network layer is 180nm-320nm, and the diameter of the fiber in the intermediate skeleton layer is 14μm-22μm.

[0015] The second object of the present application is to provide a preparation method of the biomass hydrogel-based adsorption material, which comprises the following steps:

[0016] (1) Dissolve a biomass substrate in an ionic liquid, add a photoinitiator and mix to obtain a spinning solution;

[0017] Under ultraviolet light, the obtained spinning solution is spun and crosslinked by a solution blowing method to obtain a bio-based hydrogel fiber network;

[0018] (2) Mix thermoplastic polymer chips and a light-heat conversion material, and prepare a non-woven fabric by a spunbonding method. The obtained non-woven fabric is subjected to a hot calendering process to obtain an intermediate skeleton;

[0019] (3) placing the bio-based hydrogel fiber web obtained in step (1) and the intermediate skeleton obtained in step (2) in the order of bio-based hydrogel fiber web, intermediate skeleton layer, and bio-based hydrogel fiber web from top to bottom, and reinforcing by using airflow piercing process to obtain the biomass hydrogel-based adsorption material.

[0020] In an embodiment of the present application, in step (1), the biomass substrate is selected from nanocellulose and / or modified keratin; the ionic liquid is selected from 1-butyl-3-methylimidazolium chloride and / or 1-ethyl-3-methylimidazolium acetate; and the mass ratio of the biomass substrate to the photoinitiator is 10-15:1.

[0021] In an embodiment of the present application, the photoinitiator is Irgacure 2959.

[0022] In an embodiment of the present application, the modified keratin is prepared by the following method:

[0023] After stirring and reacting the keratin with a methacrylic anhydride solution, dialysis, and drying, a methacrylated keratin (FK-MA) is obtained.

[0024] In an embodiment of the present application, the content of nanocellulose in the spinning solution is 12wt%-18wt%; the content of modified keratin is 25wt%-35wt%; and the content of photoinitiator is 4wt%-8wt%.

[0025] In an embodiment of the present application, the process parameters of the photo-crosslinking are: when the hydrogel fiber is ultraviolet-crosslinked, the ultraviolet light intensity is 25mW / m 2 , and the light exposure time is 1min-5min.

[0026] In an embodiment of the present application, in step (1), the spinning parameters of the solution blowing method are: the spinning solution flow rate is 8mL / h-16mL / h, the needle distance from the receiving web is 25cm-55cm, the airflow pressure is 0.1MPa-0.6MPa, and the auxiliary electric field voltage is 6kV-15kV.

[0027] In an embodiment of the present application, in step (2), the thermoplastic polymer is selected from ethylene-vinyl alcohol copolymer and / or polyurethane; the light-heat conversion material is selected from carbide and / or metal oxide; and the mass ratio of the thermoplastic polymer chip to the light-heat conversion material is 18-23:1.

[0028] In an embodiment of the present application, the metal oxide is zirconium carbide and / or aluminum oxide.

[0029] In one embodiment of the present application, the mass percentage of the ethylene-vinyl alcohol copolymer is 30%-55%, the mass percentage of the polyurethane is 45%-70%, and the mass percentage of the light-heat conversion material is 5%-12%.

[0030] In one embodiment of the present application, in step (2), the process parameters of the spun-bonding method are as follows: the spinning temperature is 140-240 DEG C, the drawing distance is 2.5-5 m, the cooling drawing is 18-28 DEG C, and the air pressure is 0.14-0.21 MPa.

[0031] In one embodiment of the present application, in step (2), the process parameters of the spun-bonding method are as follows: the spinning temperature is 140-240 DEG C, the drawing distance is 2.5-5 m, the cooling drawing is 18-28 DEG C, and the air pressure is 0.14-0.21 MPa.

[0032] In one embodiment of the present application, in step (2), the temperature of the hot roller is 58-68 DEG C.

[0033] In one embodiment of the present application, in step (3), the parameters of the air flow piercing process are as follows: the gas pressure is 0.18-0.36 MPa, the gas piercing needle density is 80-260 needles / m, and the air flow diameter is 150-235 nm.

[0034] The third object of the present application is to provide the application of the biomass hydrogel-based adsorption material in wastewater treatment.

[0035] The present application utilizes free radical polyaddition type photo-crosslinking reaction to prepare upper and lower layer bio-based fibrous hydrogel. Acrylate / oligomer containing double bonds is used to graft modify bio-based macromolecules, acrylate or acrylamide groups are introduced on the end groups or side groups of the macromolecules to synthesize reactive macromolecules, and under UV irradiation, photo-crosslinking reaction can realize the preparation of hydrogel.

[0036] Compared with the prior art, the above technical solution of the present application has the following advantages:

[0037] The application provides a biomass hydrogel-based adsorption material and a preparation method and application thereof.

[0038] Compared with the hydrogel block solid, the hydrogel is prepared into a nano network form, and the two structures of the hydrogel and the nano fiber network are integrated, so that the material has the functional characteristics of the hydrogel and the structural advantages of the nano fiber; the nano composite hydrogel mechanical enhancement mechanism is used, the nano cellulose is used as a reinforcing body, and the molecular chains of the protein hydrogel are wound on the surface of the nano cellulose through physical or chemical bonds; when the hydrogel is subjected to external force, the molecular chains transmit stress to the nano cellulose, so as to disperse stress and avoid stress concentration, thereby enhancing the mechanical properties of the hydrogel fiber.

[0039] Compared with the fiber-like hydrogel prepared by the wet method and electrospinning, the solution blowing method has higher production efficiency; the specific surface area is larger, more active sites are provided for ion adsorption in wastewater, molecules or ions can diffuse into the three-dimensional network system, the adsorption sites in the nano fiber are fully utilized, and the adsorption performance of the material is enhanced.

[0040] The intermediate layer network skeleton provides solid support to increase the force while having a large specific surface area and increasing the adsorption sites; the photo-thermal conversion material is doped, light energy is converted into heat energy, the kinetic energy of dye molecules in the solution is increased, and the adsorption performance of the material is improved; the airflow piercing process is used, under the action of the airflow generated by the direct reflection of the airflow or the drag net reflection, the fibers are relatively moved, rearranged and intertwined, and the three-layer fiber net is compounded and reinforced; compared with the water jet reinforcement, the airflow piercing reinforcement avoids a large amount of water, and saves cost; compared with the needle punching reinforcement, since the needle and the fiber are in rigid contact, the damage to the fiber in the reinforcement process is reduced, and the mechanical properties of the material are ensured; it can be seen that the solution blowing spinning, photo-crosslinking technology, spun-bonding method and airflow piercing method are used to prepare a multi-layer composite structure, through the mutual cooperation and synergistic effect between the layers, the biomass hydrogel-based adsorption material finally has excellent adsorption performance and good mechanical properties.

[0040] The keratin and cellulose have the advantages of rich source and biodegradation, and are used as hydrogel fiber raw materials, which has important significance for the reuse of waste. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to make the content of the application more easily understood, the application is further described in detail below according to specific embodiments of the application and in combination with the drawings, in which

[0042] Figure 1 The preparation process flow chart of the biomass hydrogel-based adsorption material in the application is shown in the figure.

[0043] Figure 2Schematic diagram of biomass hydrogel-based adsorption material in the present application;

[0044] Description of the figures: 101 is the upper layer of the bio-based hydrogel fiber network, 102 is the middle skeleton layer; 103 is the lower layer of the bio-based hydrogel fiber network. DETAILED DESCRIPTION

[0045] The present application will be further described below in conjunction with the drawings and specific examples, so that those skilled in the art can better understand the present application and implement it. The examples are not intended to limit the present application.

[0046] The materials used in the following examples are commercially available unless otherwise specified. If the experimental method is not specified, it is usually carried out under conventional conditions or according to the manufacturer's recommended conditions.

[0047] Performance test method

[0048] (1) Mechanical properties: The tensile test of the adsorption material sample was carried out at room temperature using a universal testing machine, and the sample was cut into dumbbell shape (10 mm long, 5 mm wide), the tensile rate was 20 mm / min. Three parallel samples were tested.

[0049] (2) Adsorption performance: Cationic dyes are one of the important and widely used dye components in the textile dyeing industry, and the present application selects common methylene blue (MB) and malachite green (MD) as pollutants for adsorption performance test.

[0050] The xerogel sample was immersed in MB and MD solution, shaken and adsorbed, and the supernatant was taken when the adsorption equilibrium was reached. The concentration of MB and MG was measured using ultraviolet-visible spectrophotometer, and the wavelength was 664 nm and 617 nm respectively. The equilibrium adsorption capacity of the hydrogel and the removal rate of the pollutants were calculated according to the formula:

[0051]

[0052]

[0053] In the formula, C0 is the initial concentration of the pollutant, unit: mg / L; C e is the equilibrium concentration of the pollutant solution after adsorption, unit: mg / L; m is the mass of the adsorption material, V is the volume of the MB / MD solution, unit: L; Q e is the equilibrium adsorption capacity, unit: mg / g; R is the removal rate, %.

[0054] The effect of adsorption conditions on the adsorption performance of the composite material was investigated by controlling the single-factor variable method, and blank and parallel experiments were performed. The variable range of the adsorption performance experiment was as follows: the pH value of the solution was adjusted to 2-9 using 1M HC1 and NaOH; the adsorption temperature was 30℃, 40℃, 50℃, and 60℃; the adsorption time was 0-48h; and the solution concentration was 50mg / L-800mg / L.

[0055] (3)Cyclic adsorption performance

[0056] The hydrogel was added to the dye solution for adsorption, and then desorbed in the desorption solution. After each adsorption-desorption cycle, the adsorption material was washed with distilled water for the next round of adsorption-desorption experiment. The biomass hydrogel-based adsorption material prepared in Example 1 was subjected to 5 times of adsorption-desorption cycle experiment.

[0057] The sources of the materials used in the examples are as follows:

[0058] Ethylene-vinyl alcohol copolymer chips EV-4405F were purchased from Yiding Plastic Raw Material (Dongluan) Co., Ltd.; polyurethane chips with the trade name 1195A were purchased from Dongluan City Jiuru Plastic Raw Material Co., Ltd.; nanocellulose CNF-H1 was purchased from Zhejiang Jingahao Green Nanometer Material Co., Ltd.; zirconium carbide 12070-14-3 was purchased from Jinzhou Haixin Metal Material Co., Ltd.; aluminum oxide 4N5G-40B was purchased from Zibo Honghao Crystal Material Co., Ltd.; and photoinitiator (Irgacure 2959, I2959) 106797-53-9 was purchased from Suzhou Saosen New Material Technology Co., Ltd.

[0059] Example 1

[0060] This example provides a preparation method of a biomass hydrogel-based adsorption material, and the preparation process flow chart is as shown in Figure 1 The specific steps are as follows:

[0061] (1) Preparation of bio-based hydrogel fiber network

[0062] The keratin was modified by using methacrylic anhydride (MA): 6g of keratin (FK) was dissolved in 200mL of phosphate buffer (pH=7.5) to obtain a FK solution with a mass concentration of 0.03g / mL, 4mL of MA solution was added, and the reaction was stirred at room temperature for 1h, and then 400mL of phosphate buffer was added for dilution to terminate the reaction. After dialysis and freeze-drying, a white solid was obtained, which was methacrylated keratin (FK-MA).

[0063]

[0064] ​Solution blowing method: take FK-MA, nanocellulose and dissolve in ionic liquid 1-ethyl-3-methylimidazole acetate, add photoinitiator Irgacure2959, stir until completely dissolved, then get the spinning solution; the obtained spinning solution is subjected to solution blowing spinning, and the obtained nanocellulose fiber network is subjected to crosslinking and compounding under the action of ultraviolet light with an intensity of 25 mW / m 2 400 nm for 3 min to initiate polymerization gel, to obtain a bio-based hydrogel fiber network, and the diameter of the hydrogel fiber in the obtained bio-based hydrogel fiber network is 220 nm.

[0065] Solution blowing spinning is also called air flow spinning method, which utilizes the principle of high-speed air flow stretching and Bernoulli principle. Under the drafting of high-speed air flow, the polymer overcomes the surface tension to form a solution jet, and the fiber is deposited on the collecting device.

[0066] In the spinning solution, the mass fraction of nanocellulose is 15%, the mass fraction of keratin is 28%, and the mass fraction of photoinitiator is 6%.

[0067] The process parameters of the blowing spinning are as follows: the flow rate of the spinning solution is 12 mL / h, the distance between the needle and the receiving net is 35 cm, the air flow pressure is 0.2 MPa, and the auxiliary electric field voltage is 8 kV.

[0068] (2) Preparation of intermediate skeleton

[0069] The ethylene-vinyl alcohol copolymer chip and the polyurethane chip are blended, silicon carbide is used as a light-heat conversion material, and after drying, the raw material components are mixed. The non-woven fabric is prepared by melt blending extrusion, drafting, cooling and laying, and the network skeleton is obtained after being reinforced by a hot calendering roller with a temperature of 60 DEG C. The diameter of the fiber is 20 microns.

[0070] The mass fraction of ethylene-vinyl alcohol copolymer in the raw material is 45%, the mass fraction of polyurethane in the raw material is 50%, and the mass fraction of zirconium carbide in the raw material is 5%.

[0071] The process parameters of the spun-bonding method are as follows: the temperature of the first zone is 150 DEG C, the temperature of the second zone is 180 DEG C, and the temperature of the third zone is 220 DEG C; the drafting distance is 3 m, the cooling drafting is 20 DEG C, and the air pressure is 0.16 MPa.

[0072] (3) Airflow puncture method reinforcement

[0073] The upper layer of the bio-based hydrogel fiber network, the intermediate skeleton and the lower layer of the bio-based hydrogel fiber network are compounded in order, and the three-layer fiber network is reinforced by using airflow puncture process. The fiber in the bio-based hydrogel fiber network is entangled and combined with the fiber in the adjacent intermediate skeleton by jet airflow, and mechanical bonding is formed. Finally, the three-layer fiber network is reinforced to obtain a biomass hydrogel-based adsorption material, and the structure is shown in Figure 2as shown.

[0074] The gas flow piercing process has a gas pressure of 0.25 MPa, a gas piercing needle density of 180 needles / m, and a gas flow diameter of 125 nm.

[0075] The biomass hydrogel-based adsorption material prepared in this embodiment has a tensile strength of 19.4 MPa, an adsorption capacity of 634.6 mg / g for MB, and a removal rate of 99.1%; an adsorption capacity of 565.3 mg / g for MG dye, and a removal rate of 87.4%. After five adsorption and desorption cycles, the adsorption capacity for MB is 434.2 mg / g, and the removal rate is 75.2%; the adsorption capacity for MG dye is 343.6 mg / g, and the removal rate is 60.3%.

[0076] Example 2

[0077] The biomass hydrogel-based adsorption material of this embodiment is prepared by a method similar to that of Example 1, except that:

[0078] In step (1) of preparing the bio-based hydrogel fiber network, the mass fraction of nanocellulose is 20%.

[0079] The diameter of the hydrogel fibers in the obtained bio-based hydrogel fiber network is 180 nm.

[0080] The biomass hydrogel-based adsorption material prepared in this embodiment has a tensile strength of 26.5 MPa, an adsorption capacity of 654.3 mg / g for MB, and a removal rate of 98.4%; an adsorption capacity of 543.6 mg / g for MG dye, and a removal rate of 87.1%.

[0081] Example 3

[0082] The biomass hydrogel-based adsorption material of this embodiment is prepared by a method similar to that of Example 1, except that:

[0083] In step (2) of preparing the intermediate skeleton, the process parameters of the spunbond method are: a drawing distance of 5 m and a wind pressure of 0.21 MPa.

[0084] The diameter of the fibers of the intermediate skeleton prepared by the spunbond method is 14 μm.

[0085] The biomass hydrogel-based adsorption material prepared in this embodiment has a tensile strength of 18.1 MPa, an adsorption capacity of 669.8 mg / g for MB, and a removal rate of 99.5%; an adsorption capacity of 572.2 mg / g for MG dye, and a removal rate of 89.4%.

[0086] Example 4

[0087] The preparation method of the biomass hydrogel-based adsorption material of the embodiment is similar to that of Embodiment 1, and the only difference is that:

[0088] In the air flow needling method for reinforcement in step (3), the air needle density is 260 needles / m.

[0089] It is tested that the tensile strength of the biomass hydrogel-based adsorption material prepared in the embodiment is 24.8 MPa; the adsorption amount of MB is 621.6 mg / g, and the removal rate is 97.8%; the adsorption amount of MG dye is 534.3 mg / g, and the removal rate is 86.3%.

[0090] Comparative Example 1

[0091] The present comparative example provides a preparation method of a composite hydrogel adsorption material, and the specific steps are as follows:

[0092] (1) Preparation of intermediate skeleton

[0093] The ethylene-vinyl alcohol copolymer chip and the polyurethane chip are blended, carbonized zirconium is used as a light-heat conversion material, and after drying of the raw material components, they are melt-blended and extruded together by using a spunbond method, drawn, cooled, and laid to prepare a non-woven fabric, which is reinforced by a hot calender roller with a temperature of 60°C to obtain an intermediate skeleton.

[0094] Among them, the mass ratio of ethylene-vinyl alcohol copolymer is 45%; the mass ratio of polyurethane is 50%; and the mass ratio of carbonized zirconium is 5%.

[0095] Among them, the process parameters of the spunbond method are: the temperature of the first zone is 150°C, the temperature of the second zone is 180°C, and the temperature of the third zone is 220°C; the drawing distance is 3 m, the cooling drawing is 20°C, and the air pressure is 0.16 MPa.

[0096] (2) Preparation of composite hydrogel adsorption material

[0097] The FK-MA and nanocellulose are dissolved in the ionic liquid 1-ethyl-3-methylimidazole acetate, and the photoinitiator Irgacure 2959 is added; the intermediate skeleton prepared by the spunbond method is immersed in the hydrogel precursor, and after saturation adsorption, the composite hydrogel adsorption material is prepared by using the photo-crosslinking technology.

[0098] Among them, the mass fraction of nanocellulose is 15%; the mass fraction of keratin is 28%; and the mass fraction of photoinitiator is 4%.

[0099] Among them, when the hydrogel fiber is ultraviolet crosslinked, the ultraviolet light intensity is 25 mW / m 2 , and the illumination time is 5 min.

[0100] The tensile strength of the adsorption material prepared by the above method is 18.4 MPa; the adsorption capacity for MB is 452.3 mg / g, and the removal rate is 63.6%; the adsorption capacity for MG dye is 315.5 mg / g, and the removal rate is 57.4%.

[0101] In Comparative Example 1, the intermediate skeleton prepared by the spun-bond method is directly immersed in the hydrogel precursor, i.e., the hydrogel precursor is infiltrated into the intermediate skeleton, to prepare a composite adsorption material. Compared with Example 1, the specific surface area of the composite adsorption material prepared by this method is small, and there are not enough active sites for adsorption. At the same time, due to the fact that the voids between the intermediate composite intermediate skeletons have been occupied by the hydrogel, there is no more space for adsorbing dyes, and the adsorption performance of the material is poor.

[0102] Comparative Example 2

[0103] (1) Preparation of bio-based hydrogel fiber network

[0104] The solution blow spinning solution is prepared as follows: FK-MA and nanocellulose are dissolved in ionic liquid 1-ethyl-3-methylimidazole acetate, and photoinitiator Irgacure 2959 is added and stirred until completely dissolved to obtain a spinning solution; the obtained spinning solution is subjected to solution blow spinning, and a polymerization gel is initiated by using a photo-crosslinking technology to prepare a bio-based hydrogel fiber adsorption material.

[0105] The mass fraction of nanocellulose is 15%, the mass fraction of keratin is 28%, and the mass fraction of photoinitiator is 4%. The process parameters of solution blow spinning are as follows: the flow rate of the spinning solution is 12 mL / h, the needle distance from the receiving net is 35 cm, the air flow pressure is 0.8 MPa, and the auxiliary electric field voltage is 8 kV.

[0106] When the hydrogel fibers are ultraviolet-crosslinked, the ultraviolet light intensity is 25 mW / m 2 , and the illumination time is 3 min.

[0107] The diameter of the hydrogel fibers in the bio-based hydrogel fiber network is 220 nm.

[0108] It is tested that the tensile strength of the bio-based hydrogel fiber adsorption material prepared in this comparative example is 5.3 MPa; the adsorption capacity for MB is 256.6 mg / g, and the removal rate is 48.5%; the adsorption capacity for MG dye is 212.3 mg / g, and the removal rate is 51.2%.

[0109] Compared with Example 1, Comparative Example 2 directly uses a solution blowing method to prepare a bio-based hydrogel fiber adsorption material, that is, without a composite intermediate skeleton as a mechanical support, the mechanical properties of the adsorption material prepared by this method are reduced; at the same time, the intermediate skeleton in the example makes the adsorption material have a larger specific surface area and more space to adsorb dyes, so the adsorption performance of the biomass hydrogel-based adsorption material prepared in Example 1 is better than that of the adsorption material prepared in Comparative Example 2.

[0110] Comparative Example 3

[0111] This comparative example provides a preparation method of a biomass hydrogel-based adsorption material, and the specific steps are as follows:

[0112] (1) Preparation of bio-based hydrogel fiber network

[0113] Prepare the spinning solution by dissolving FK-MA in ionic liquid 1-ethyl-3-methyl imidazole acetate, adding a photoinitiator Irgacure 2959, stirring until completely dissolved, and then obtaining the spinning solution; the obtained spinning solution is subjected to solution blowing spinning, and a polymerization gel is initiated by using a photo-crosslinking technology to prepare a bio-based hydrogel fiber network.

[0114] Among them, the mass fraction of keratin is 30%; the mass fraction of the photoinitiator is 5%.

[0115] The process parameters of the blowing spinning are as follows: the flow rate of the spinning solution is 12 mL / h, the needle distance from the receiving net is 35 cm, the air flow pressure is 0.8 MPa, and the auxiliary electric field voltage is 8 kV.

[0116] Among them, when the hydrogel fiber is ultraviolet crosslinked, the ultraviolet light intensity is 25 mW / m 2 , and the illumination time is 3 min;

[0117] (2) The method for preparing the intermediate skeleton is the same as that in Example 1.

[0118] (3) The method for reinforcing by air flow puncture is the same as that in Example 1.

[0119] The tensile strength of the adsorption material prepared in this comparative example is 11.9 MPa; the adsorption capacity for MB is 534.2 mg / g, and the removal rate is 83.4%; the adsorption capacity for MG dye is 455.4 mg / g, and the removal rate is 81.4%.

[0120] Compared with Example 1, no nanocellulose is added as a reinforcing body in Comparative Example 3, and the mechanical properties of the adsorption material are reduced. This is because in the example, nanocellulose is added as a reinforcing body, and the molecular chains of the protein hydrogel are entangled on the surface of the nanocellulose through physical or chemical bonds. When the hydrogel is subjected to external force, the molecular chains transfer the stress to the nanocellulose, achieve the effect of dispersing stress, and enhance the mechanical properties of the hydrogel fiber.

[0121] Comparative Example 4

[0122] The preparation method of the biomass hydrogel-based adsorption material of the present comparative example is similar to that of Example 1, except that:

[0123] In the process of preparing the intermediate skeleton in step (2), no photo-thermal conversion material is added.

[0124] The tensile strength of the adsorption material prepared by the above method is 18.4 MPa; the adsorption capacity for MB is 364.5 mg / g, and the removal rate is 56.6%; the adsorption capacity for MG dye is 345.4 mg / g, and the removal rate is 68.9%.

[0125] Compared with Example 1, no photo-thermal conversion material is added in Comparative Example 4, which cannot convert light energy into heat energy, cannot accelerate the kinetic energy of dye molecules in wastewater, cannot accelerate the operation of the adsorption process, and has low adsorption performance of the material.

[0126] Comparative Example 5

[0127] The preparation method of the biomass hydrogel-based adsorption material of the present comparative example is similar to that of Example 1, except that:

[0128] In step (3), a water jet method is used for reinforcement: after pre-wetting the intermediate skeleton to remove air in the fiber web, the upper bio-based hydrogel fiber network, the intermediate skeleton, and the lower bio-based hydrogel fiber network are sequentially compounded, and the three-layer fiber web is reinforced by a water jet process through forward and reverse processes.

[0129] The parameters of the water jet process are: water needle pressure is 1.8 MPa; water needle arrangement density is 780 strokes / m; water needle diameter is 5 μm. The tensile strength of the adsorption material prepared in the present comparative example is 8.2 MPa; the adsorption capacity for MB is 474.6 mg / g, and the removal rate is 65.6%; the adsorption capacity for MG dye is 375.8 mg / g, and the removal rate is 78.4%.

[0130] Compared with Example 1, Comparative Example 5 uses a water jet method to reinforce the composite material, which requires a large amount of water, and the water requirement is strict to ensure the continuous operation of the process, which is high in cost, and the high-speed water flow causes damage to the fibers, so the mechanical properties of the material are relatively poor.

[0131] Results analysis

[0132] The adsorption performance and mechanical property test results of the biomass hydrogel-based adsorption materials prepared in Examples 1-4 and Comparative Examples 1-5 are shown in Table 1:

[0133] Table 1 Performance test results of biomass hydrogel-based adsorption materials

[0134]

[0135] In summary, the biomass hydrogel-based adsorption material prepared in the examples has excellent adsorption performance and good mechanical properties. In consideration of various factors such as production process requirements, energy consumption and product performance, compared with other comparative examples, the method of the examples is more suitable for preparing adsorption materials.

[0136] Obviously, the above examples are only examples for the sake of clarity, and are not a limitation on the embodiments. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. It is not necessary and impossible to enumerate all the embodiments here. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A biomass hydrogel-based adsorbent material, characterized in that, The biomass hydrogel-based adsorption material is a three-layer structure, from top to bottom in turn: a bio-based hydrogel fiber network layer, an intermediate skeleton layer and a bio-based hydrogel fiber network layer. The bio-based hydrogel fiber network layer is prepared by using a solution blowing method and a photo-crosslinking technology. The intermediate skeleton layer is prepared by using a spun-bonding method process. The bio-based hydrogel fiber network layer and the intermediate skeleton layer are compounded by using an air flow piercing process. The preparation method of the biomass hydrogel-based adsorption material comprises the following steps: (1) Dissolve a biomass substrate in an ionic liquid, add a photo initiator and mix to obtain a spinning solution; Under ultraviolet light, the obtained spinning solution is spun and crosslinked by using a solution blowing method to obtain a bio-based hydrogel fiber network; (2) Mix thermoplastic polymer chips with a light-heat conversion material, prepare a non-woven fabric by using a spun-bonding method, and obtain an intermediate skeleton by using a hot calendering roller process; (3) Place the bio-based hydrogel fiber network obtained in step (1) and the intermediate skeleton obtained in step (2) in the order of bio-based hydrogel fiber network, intermediate skeleton layer and bio-based hydrogel fiber network from top to bottom, and compound them by using an air flow piercing process to obtain the biomass hydrogel-based adsorption material; In step (1), the biomass substrate is selected from nanocellulose and / or modified keratin; the ionic liquid is selected from 1-butyl-3-methylimidazolium chloride and / or 1-ethyl-3-methylimidazolium acetate; In step (2), the thermoplastic polymer is selected from ethylene-vinyl alcohol copolymer and / or polyurethane; the light-heat conversion material is selected from carbide and / or metal oxide.

2. The biomass hydrogel-based sorption material according to claim 1, wherein The diameter of the hydrogel fiber in the bio-based hydrogel fiber network layer is 180 nm-320 nm; the diameter of the fiber in the intermediate skeleton layer is 14 μm-22 μm.

3. The method of producing a biomass hydrogel-based sorption material according to claim 1 or 2, characterized in that, The preparation method comprises the following steps: (1) Dissolve a biomass substrate in an ionic liquid, add a photo initiator and mix to obtain a spinning solution; Under ultraviolet light, the obtained spinning solution is spun and crosslinked by using a solution blowing method to obtain a bio-based hydrogel fiber network; (2) Mix thermoplastic polymer chips with a light-heat conversion material, prepare a non-woven fabric by using a spun-bonding method, and obtain an intermediate skeleton by using a hot calendering roller process; (3) Place the bio-based hydrogel fiber network obtained in step (1) and the intermediate skeleton obtained in step (2) in the order of bio-based hydrogel fiber network, intermediate skeleton layer and bio-based hydrogel fiber network from top to bottom, and compound them by using an air flow piercing process to obtain the biomass hydrogel-based adsorption material; In step (1), the biomass substrate is selected from nanocellulose and / or modified keratin; the ionic liquid is selected from 1-butyl-3-methylimidazolium chloride and / or 1-ethyl-3-methylimidazolium acetate; In step (2), the thermoplastic polymer is selected from ethylene-vinyl alcohol copolymer and / or polyurethane; the light-heat conversion material is selected from carbide and / or metal oxide.

4. The production method according to claim 3, characterized by, In step (1), the mass ratio of the biomass substrate to the photo initiator is 10-15:

1.

5. The preparation method according to claim 3, characterized in that In step (1), the spinning parameters of the blowing method are as follows: the flow rate of the spinning solution is 8 mL / h-16 mL / h, the distance between the needle and the receiving net is 25 cm-55 cm, the air flow pressure is 0.1 MPa-0.6 MPa, and the auxiliary electric field voltage is 6 kV-15 kV.

6. The preparation method according to claim 3, characterized in that In step (2), the mass ratio of the thermoplastic polymer chip to the light-heat conversion material is 18-23:

1.

7. The preparation method according to claim 3, characterized in that In step (2), the process parameters of the spun-bonding method are as follows: the spinning temperature is 140℃-240℃, the drawing distance is 2.5 m-5 m, the cooling drawing is 18℃-28℃, and the wind pressure is 0.14 MPa-0.21 MPa.

8. The preparation method according to claim 3, characterized in that In step (2), the temperature of the hot rolling roller is 58℃-68℃.

9. The production method according to claim 3, wherein In step (3), the parameters of the air flow piercing process are as follows: the gas pressure is 0.18 MPa-0.36 MPa; the gas piercing needle density is 80 needles / m-260 needles / m, and the air flow diameter is 150 nm-235 nm.

10. The use of the biomass hydrogel-based adsorption material according to claim 1 or 2 in wastewater treatment.

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