CN113117651B

CN113117651B - Method for preparing glass fiber-metal organic framework composite film

Info

Publication number: CN113117651B
Application number: CN202110425669.5A
Authority: CN
Inventors: 傅迎春; 张琪; 李延斌; 应义斌
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2022-06-17
Anticipated expiration: 2041-04-20
Also published as: CN113117651A

Abstract

The invention discloses a method for preparing a glass fiber-metal organic framework composite film. Modifying the cleaned glass fiber membrane by using 3-aminopropyltriethoxysilane and glutaraldehyde step by step, then crosslinking biomolecules to obtain a biomolecule-modified glass fiber membrane, dissolving the biomolecule-modified glass fiber membrane in a solution containing metal ions, adding a solution containing ligands for reaction, sequentially cleaning and drying after the reaction is finished to obtain a glass fiber membrane-modified metal organic framework composite membrane, and generating different metal organic framework materials by using metal ion solutions with different concentrations and ligand solutions with different concentrations to finally obtain different glass fiber membrane-modified metal organic framework composite membranes. The invention solves the problem that the metal organic framework material on the surface of the inert substrate is difficult to form a film, realizes the preparation of the stable glass fiber-metal organic framework composite film, has high load rate, can realize the adsorption of various organic hazards by the composite film, and stably works in various extreme environments.

Description

Method for preparing glass fiber-metal organic framework composite film

Technical Field

The invention relates to a novel method for preparing a high-performance composite film, in particular to a method for preparing a glass fiber-metal organic framework composite film and application of the prepared glass fiber-metal organic framework composite film in enrichment of organic harmful substances.

Technical Field

Fiber membranes play a key role in separation, sensing, adsorption and catalysis applications in the fields of modern energy, agriculture, food, environment and medicine. The hybrid membrane can overcome the single function of the traditional membrane, and the combination of the hybrid membrane and a nanometer material shows enhanced function and even synergistic characteristics, thereby attracting wide attention. At present, two basic difficulties exist in preparing fiber-MOFs hybrid membranes, namely, selecting a proper fiber substrate and an efficient MOFs growth strategy.

There are two types of commonly used fibrous membranes, including Synthetic Polymer Fibers (SPF), such as polyacrylonitrile, polyurethane, polypropylene, polyvinylidene fluoride and nylon, and protein fibers derived from living organisms, such as silk and spider fibers. SPF is widely available and inexpensive, but lacks surface functional sites. The rich functional sites of biological fibers can promote the nucleation and growth of nanomaterials, however, the high cost and complexity of manufacture limit their further applications. In addition, at present, much attention is paid to the growth of MOFs on the surface of the fiber membrane, and the attention on the stability of the fiber membrane is insufficient.

In recent years, biomimetic mineralization growth is a newly developed method for in-situ growth of nano materials, and existing work shows that biomolecule/biomolecule devices (DNA, enzyme, cell and protein/protein-fiber membrane) can trigger the growth of MOF through biomimetic mineralization and have the functions of enhancement and even protection. However, the limitation is that it is difficult to further utilize the functional biomolecule MOF nanoparticles to prepare membranes, and biofiber membranes such as protein fiber membranes (e.g. electrospun proteins) are not readily available and are expensive.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a method for preparing a glass fiber-metal organic framework composite film and application thereof in organic hazard adsorption treatment in a water body.

The technical scheme adopted by the invention is as follows:

the preparation method of the glass fiber-metal organic framework composite film comprises the following specific steps:

1) modifying the cleaned glass fiber membrane by 3-Aminopropyltriethoxysilane (APTES) and Glutaraldehyde (GA) step by step, and then crosslinking by using biomolecules to obtain a biomolecule modified glass fiber membrane;

2) dissolving the biomolecule-modified glass fiber membrane obtained in the step 1) in a metal ion A solution, then adding a ligand B solution for oscillation reaction, reacting the metal ion A solution and the ligand B solution on the biomolecule-modified glass fiber membrane to generate a metal organic framework material MOFs, and after the reaction is finished, sequentially cleaning and drying to obtain the metal organic framework material-modified glass fiber composite membrane GF @ MOFs.

The glass fiber comprises glass fiber cloth, glass fiber yarn, a hollow glass fiber pipe and chopped glass fiber; glass articles including capillary glass tubes, glass sheets, glass plates, glass blocks, physico-chemically modified glass and chemically modified glass may also be used in place of glass fibers.

In the step 1), 3-aminopropyltriethoxysilane is diluted with acetone, and the volume ratio of the 3-aminopropyltriethoxysilane to the acetone is (1: 199) - (1: 4) (ii) a Diluting glutaraldehyde with deionized water, wherein the volume ratio of the glutaraldehyde to the water is (1: 199) - (1: 9); the biomolecule is dissolved by deionized water, and the concentration of the biomolecule is 0.5mg mL^-1-20mg mL^-1。

In the step 2), the metal ions A in the metal ion A solution include but are not limited to Zn²⁺、Co²⁺、Fe²⁺、Cu²⁺、Eu³ ⁺Or Tb³⁺(ii) a Ligand B in the ligand B solution includes but is not limited to 2-methylimidazole, terephthalic acid or fumaric acid; and reacting the metal ion A solution and the ligand B solution with different concentrations on the glass fiber GF membrane modified by the biological molecules to generate different Metal Organic Frameworks (MOFs).

In the step 2), the volume of the metal ion A solution is the same as that of the ligand B solution, the concentration of the metal ion A in the metal ion A solution is 5mM-200mM, and the concentration of the ligand B in the ligand B solution is 100 mM-2M.

In the step 2), the biomolecule is protein, polypeptide or DNA; proteins include, but are not limited to, bovine serum albumin, casein, lactalbumin, myoprotein, soy protein, glutenin, gluten, gliadin, zein, legumin, fibroin, and fibrin.

In the step 1), the modification temperature of the 3-aminopropyltriethoxysilane is 4-40 ℃, and the modification time is 0.01-12 h.

In the step 1), the modification temperature of the glutaraldehyde is 4-40 ℃, and the modification time is 0.01-4 h.

In the step 1), the temperature for crosslinking the biomolecules is 4-40 ℃, and the time for crosslinking is 0.01-24 h.

In the step 2), the reaction temperature is 4-40 ℃, and the reaction time is 0.01-24 h; the drying temperature is 40-60 deg.C, and the drying time is not less than 12 h.

And finally, taking out the metal organic framework Materials (MOFs) formed by the reaction on the Glass Fiber (GF) film modified by the biomolecules, cleaning and drying to obtain the metal organic framework composite film (GF @ MOFs) modified by the Glass Fiber (GF) film. The metal organic frame Materials (MOFs) are metal salts (Zn)²⁺，Co²⁺，Fe²⁺，Cu²⁺，Eu³⁺，Tb³⁺And the like) and organic ligands (2-methylimidazole, Terephthalic acid (BDC), Fumaric acid, and the like) as precursors, including ZIF-8, ZIF-L, ZIF-67, MIL-88A, HKUST-1, Eu-BDC, Tb-BDC, and the like. In a specific embodiment, the metal ion A solution is Zn²⁺The ionic water solution and the ligand B solution are 2-methylimidazole water solutions and Zn with different concentrations²⁺The Metal Organic Frameworks (MOFs) grown from the ionic aqueous solution and the 2-methylimidazole aqueous solution comprise ZIF-8, ZIF-L-1 and ZIF-L-2, and the prepared GF @ MOFs composite films are GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2 respectively.

The GF @ ZIFs composite film of the invention is used for treating organic harmful substances in water such as dyes and antibiotics, such as: malachite green, tetracycline, and the like.

The invention mainly focuses on and solves the technical difficulty of preparing the metal organic framework material on the surface of the inert fiber substrate, and integrates the performance advantages of the substrate and the nano material. In the implementation example, a large number of active sites are endowed on the surface of inert GF through gradual chemical modification and crosslinking, and three metal organic framework materials (ZIF-8, ZIF-L-1 and ZIF-L-2) which are homologous but have different morphologies and loading rates (14%, 31% and 47%) are biomimetically grown on the surface of the GF by adjusting the concentrations of metal and ligands. The prepared GF @ ZIFs composite film is used for treating the water solution containing the pollutants in the modes of static adsorption/suction filtration and the like. The composite film is characterized systematically by the characterization means of morphology, structure and performance such as a scanning electron microscope, an energy spectrum, X-ray diffraction, thermogravimetric analysis, specific surface area analysis and the like, and the characterization record is carried out by the means of absorbance, digital picture shooting and the like on the aqueous solution containing the hazardous substances.

According to the invention, chemical modification-biological crosslinking is utilized to realize GF surface modification of biomolecules, and three MOFs shell layers with the thickness of 500nm-2 mu m are biomimetically grown on the GF surface by adjusting the concentration of a reactant solution. The surface functional sites of the inert substrate are manually endowed, the properties of the substrate can be fully utilized, and the substrate is combined with a porous crystal material to prepare a novel composite film which has the functions of collecting organic harmful substances and resisting various environmental interferences.

The GF @ ZIFs composite film prepared by the method has the following advantages:

1. the invention adopts chemical modification and biological crosslinking to provide a large number of functional sites for the growth of the nano material on the surface of the inert fiber film, and solves the technical problems of difficult growth of the nano material on the surface of the inert substrate and poor preparation load of the MOFs film by the GF @ ZIFs composite film prepared by in-situ growth.

2. The bionic combination between BSA and MOFs, and the MOFs particles loaded on the prepared composite film have the characteristics of continuity, uniformity, high loading rate, adjustable morphology and the like.

3. By integrating the strong stability of the glass fiber membrane and the excellent adsorption performance of the metal organic framework material, the prepared composite film can realize the efficient adsorption of organic harmful substances under the conditions of polar organic solvents, extreme working temperature and pH value.

In summary, the invention solves the problem that the metal organic framework material on the surface of the inert substrate is difficult to form a film, realizes the preparation of the stable glass fiber-metal organic framework composite film, has high load rate, can realize the adsorption of various organic harmful substances, and stably works in various extreme environments.

Drawings

FIG. 1 is a schematic diagram of the present invention;

FIG. 2 is the scanning electron microscope image of step-by-step modification, growth and Glass Fiber (GF) @ Metal Organic Framework (MOFs) of the glass fiber membrane; FIGS. 2A-2J are GF, GF-APTES, GF-APTES-GA, GF-APTES-GA-BSA, GF-ZIF-8, GF-APTES-ZIF-8, GF-APTES-GA-ZIF-8, and GF-APTES-GA-BSA @ ZIF-8, GF-APTES-GA-BSA @ ZIF-L-1, GF-APTES-GA-BSA @ ZIF-L-2, respectively, for growing three MOFs.

3A-3C are energy spectra of GF @ MOFs in three morphologies, and 3D is an infrared characterization of GF step modification and GF @ ZIFs, ZIFs;

FIG. 4A is an X-ray diffraction pattern of GF film, mimicking ZIF-8, ZIFs, GF @ ZIFs; FIG. 4B is a graph of isothermal desorption curves for GF @ BSA, ZIFs, GF @ ZIFs; FIGS. 4C and 4D are thermograms of GF @ BSA, GF @ ZIFs and ZIFs;

in the figure 5, A and B are respectively GF @ ZIFs membrane adsorption 140mg L^-1And 900mg L^-1Absorption spectra of the solution before and after dye (malachite green) adsorption;

FIG. 6 is a diagram showing the absorption spectra of a solution before and after the adsorption of an antibiotic (tetracycline) to a GF @ ZIFs membrane;

FIG. 7A is a GF @ ZIFs membrane-suction filtration apparatus, and 7B is an absorption spectrum of malachite green before and after suction filtration;

in FIG. 8, A, B, C and D are the adsorption of GF @ BSA, GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2 membranes, respectively, on malachite green in water and acetonitrile, an organic solvent, at 70 ℃;

FIG. 9 shows the adsorption of methyl orange by GF @ ZIFs membrane in NaOH solution.

Detailed Description

The invention will be described in further detail with reference to the following drawings and specific embodiments.

In order to make the technical solutions of the present invention better understood, the present invention is further described below with reference to the following examples, but the present invention is not limited to the following examples.

The examples of the invention are as follows: fig. 1 is a schematic diagram of the present invention.

Example 1

The method comprises the following steps: ultrasonically cleaning a cut Glass Fiber (GF) film with the diameter of 1.1cm for 5min by using a mixed solution of deionized water, ethanol and deionized water, drying the Glass Fiber (GF) film in an oven at 80 ℃ for 2h, then soaking the GF film in an acetone solution of 3-Aminopropyltriethoxysilane (APTES) with the volume fraction of 5%, modifying the GF film for 6h at normal temperature, cleaning the GF film by using acetone, and drying the GF film in the oven at 80 ℃ for 2h after cleaning; then it was modified at room temperature for 2h by immersing it in a deionized water solution of Glutaraldehyde (GA) with a volume fraction of 4%, followed by washing with deionized water and drying in an oven at 50 ℃ for 2h, and the GF film was placed in 10mg mL^-1The BSA solution is modified for 12 hours at normal temperature, and finally, the glass fiber GF @ BSA modified by Bovine Serum Albumin (BSA) is obtained by washing with deionized water and drying in an oven at 50 ℃ for 2 hours.

Step two: vertically immersing a glass fiber GF film GF @ BSA modified by BSA in a 4mL centrifuge tube, vertically immersing the glass fiber GF film GF @ BSA in 1.5mL of 18.4mM zinc nitrate hexahydrate solution for 1min, then adding 1.5mL of 1.38M 2-methylimidazole solution, oscillating for 10s, placing the solution at normal temperature for reaction for 12h, reacting the zinc nitrate hexahydrate solution and the 2-methylimidazole solution on the glass fiber GF film modified by BSA to generate a metal organic framework material ZIF-8, then sequentially washing and drying in an oven at 60 ℃ to obtain a GF @ ZIF-8 composite film, and collecting the obtained GF @ ZIF-8 composite film for later use.

Example 2

The method comprises the following steps: ultrasonically cleaning the cut GF film with the diameter of 1.1cm for 5min by using deionized water, ethanol and deionized water mixed solution respectively, drying the GF film in an oven at the temperature of 80 ℃ for 2h, then soaking the GF film in acetone solution of APTES with the volume fraction of 5%, modifying the GF film at the normal temperature for 6h, cleaning the GF film by using acetone, and drying the GF film in the oven at the temperature of 80 ℃ after cleaning2 h; then immersing the membrane in a deionized water solution of GA with the volume fraction of 4% for modification at the normal temperature for 2h, washing with deionized water, drying in an oven at 50 ℃ for 2h, and placing the GF membrane in 10mg mL^-1The glass fiber GF @ BSA modified by BSA is obtained by modifying the BSA solution for 12h at normal temperature, finally washing with deionized water and drying in an oven at 50 ℃ for 2 h.

Step two: vertically immersing a glass fiber GF (glass fiber) film GF @ BSA modified by BSA in a 4mL centrifuge tube for 1min in 1.5mL of 40mM zinc nitrate hexahydrate solution, then adding 1.5mL of 0.6M 2-methylimidazole solution, oscillating for 10s, placing the solution at normal temperature for reaction for 12h, reacting the zinc nitrate hexahydrate solution and the 2-methylimidazole solution on the glass fiber GF film modified by the BSA to generate a metal organic framework material ZIF-L-1, then sequentially cleaning and drying in an oven at 60 ℃ to obtain a GF @ ZIF-L-1 composite film, and collecting the obtained GF @ ZIF-L-1 composite film for later use.

Example 3

The method comprises the following steps: ultrasonically cleaning the cut GF film with the diameter of 1.1cm for 5min by using deionized water, ethanol and deionized water mixed solution respectively, then drying the GF film in an oven at the temperature of 80 ℃ for 2h, then soaking the GF film in acetone solution of APTES with the volume fraction of 5 percent, modifying the GF film at the normal temperature for 6h, cleaning the GF film by using acetone, and drying the GF film in the oven at the temperature of 80 ℃ for 2h after cleaning; then it was immersed in a deionized water solution of GA with a volume fraction of 4% at room temperature for 2h for modification, followed by washing with deionized water and drying in an oven at 50 ℃ for 2h, and the GF membrane was placed in 10mg mL^-1The glass fiber GF @ BSA modified by BSA is obtained by modifying the BSA solution for 12h at normal temperature, finally washing with deionized water and drying in an oven at 50 ℃ for 2 h.

Step two: vertically immersing a glass fiber GF film GF @ BSA modified by BSA in a 4mL centrifuge tube, vertically immersing the glass fiber GF film GF @ BSA in 1.5mL of 120mM zinc nitrate hexahydrate solution for 1min, then adding 1.5mL of 1.2M 2-methylimidazole solution, oscillating for 10s, placing the solution at normal temperature for reaction for 12h, reacting the zinc nitrate hexahydrate solution and the 2-methylimidazole solution on the glass fiber GF film modified by the BSA to generate a metal organic framework material ZIF-L-2, then sequentially washing and drying in an oven at 60 ℃ to obtain a GF @ ZIF-L-2 composite film, and collecting the obtained GF @ ZIF-L-2 composite film for later use.

The tests of examples 1-3 were as follows:

1. characterization of the composite film

As shown in fig. 2, GF membranes modified BSA by stepwise chemical modification as described in the examples. When the BSA obtained in each step of step-by-step modification is soaked in a ZIF-8 growth solution for growth, only a small amount of ZIF-8 can be found in the gaps of the fibers and can not grow along the fiber surface because the functional sites on the GF surface are few. After APTES, GA step modification, the fibers remain smooth and MOFs growth thereon is still limited due to the limited role of the silyl and aldehyde groups as functional sites. The smoothness of the GF @ BSA membrane decreased slightly with the completion of the BSA modification step, since all fibers were surrounded by BSA to form functional sites. Under the same growth conditions as before, nearly 100% coverage of the particulate ZIF-8 was seen, and an MOF shell about 500nm thick was formed.

Different ZIFs are grown by using metals and organic ligands with different concentrations, ZIF-L-1 and ZIF-L-2 in sheet petal and wheat spike shapes can be obtained, and GF @ ZIF-1 and GF @ ZIF-2 composite films with fiber diameters of 4 mu m and 5 mu m are finally formed.

Other characterization methods, such as energy scattering spectroscopy (EDS), powder X-ray diffraction (PXRD), fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption-desorption (BET), and thermogravimetric analysis (TGA), were performed to comprehensively analyze the resulting composite film.

From the EDS images, it can be seen that the GF @ ZIFs of the three morphologies show different morphologies, as shown in fig. 3A-3C. Carbon elements in the ZIFs are uniformly distributed on the surface of the GF, and the biomimetic mineralization growth of the core-shell GF @ ZIFs is further shown. FIG. 3D is a FT-IR spectrum, qualitatively illustrating the modification process, for GF, the Si-O bond itself is at 1010cm^-1There is a clear and intense broad peak nearby. After APTES modification, new Si-C (890-690 cm)^-1) And Si-O (1100 to 1000 cm)^-1) The occurrence of bonds may be covered by a strong broad peak of GF. After the last step of BSA modification, GF @ BSA membrane was at 1006cm^-1、1529cm^-1And 1652cm^-1Three peaks appeared nearby and belong toAmides I, II on Si-O, BSA. For all GF @ ZIF films and ZIF powders, there were characteristic imidazole peaks at 759cm-1 and 694cm-1 at 421cm^-1Has Zn-N peak.

Fig. 4A is PXRD results, showing steamed bun peaks (20 ° to 30 °) for GF indicating self-amorphous structure. GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2 membranes, ZIF-8, ZIF-L-1 and ZIF-L-2 powders had clearly corresponding crystal diffraction peak positions, indicating that the ZIF powders and GF @ ZIFs membranes were successfully prepared. As shown in FIG. 4B, the BET surface area of the irregular macroporous and dense structures of the GF and GF @ BSA films, respectively, was 2.0m² g^-1And 1.9m² g^-1. After ZIF-8 biomimetic mineralization growth, due to ZIF-8 powder (1046.8 m)² g^-1) Has a large specific surface area, and the obtained GF @ ZIF-8 film (137.4 m)² g^-1) Increased compared to GF @ BSA membrane. The BET surface area values of the other two GF @ ZIFs films and the two ZIF powders also showed the same behavior, 12.5m each² g^-1、2.6m2 g^-1And 41.4m² g^-1、3.5m² g^-1. The above data all indicate successful growth of ZIFs on GF surfaces.

2. Load rate analysis

As shown in fig. 4C and 4D, the load ratios of ZIFs on GF membranes were evaluated by calculating the weight changes before and after growth of ZIFs on GF membranes using TGA data. The change in the weight ratio of the ZIFs to the prepared composite film was defined as the loading rate. According to the weight of the composite film, GF and ZIFs at three different temperature points of 540 ℃, 565 ℃ and 590 ℃, the load ratios of the three ZIFs on the GF are respectively 14 percent (ZIF-8), 31 percent (ZIF-L-1) and 47 percent (ZIF-L-2).

3. Adsorption applications

Industrial and agricultural environments cause the accumulation of organic pollutants in water and therefore rapid and efficient membrane treatment techniques are needed. As common contaminants in water, organic dyes (malachite green (MG)) and antibiotics (tetracycline hydrochloride (TC)) were chosen as models. MG and TC were collected by making GF @ ZIF membranes of different morphology.

In each independent experiment, GF @ BSA film, ZIFs powder and GF @ ZIFs film are placed in an aqueous solution containing organic pollutants, and the pollutants (with the same concentration in a given time period) in the solution are quantitatively detected. And reading the absorbance of the organic dye by using a microplate reader, and detecting the absorbance value of the antibiotic by using an ultraviolet visible spectrometer. The adsorption capacity of the adsorbent to the adsorbate was calculated in units of milligrams (dye or antibiotic)/grams (GF @ BSA membrane, ZIF powder or GF @ ZIF membrane), and the results were calibrated using a correlation calibration curve.

And (3) calculating the mass of the membrane in the adsorption process according to the load rate for all organic dyes and antibiotics, and enabling the weight of GF @ BSA in each GF @ ZIFs membrane to be equal so as to obtain the adsorption capacity of the ZIFs.

In literature reports, ZIF-8 has 1667MG g on MG^-1High adsorption capacity. Two different concentrations of MG were collected using GF @ ZIF membranes. Briefly, 1mL of 140mg L of each of 2mg GF @ BSA, 2mg ZIF-8, 2.4mg GF @ ZIF-8 (14% ZIF-8 loading) was adsorbed^-1MG solution of (a). After 6 hours, the residual MG intensity in the solution was calculated as (absorbance at 618 nm). The results are shown in FIG. 5 for a GF @ BSA membrane pair of 140mg L^-1The MG adsorption rate was about 0.2%, and the digital photographs with the drawings showed little discoloration. The removal rates for GF @ ZIFs were 95.0%, and 95.4%, respectively. Whereas ZIF powder also showed 95.6%, 95.4% and 95.0% removal.

Other concentrations were further used to calculate the adsorption capacity and rate of the GF @ ZIF membranes prepared. As before, 2mg GF @ BSA film, 2mg ZIF-8, 2.4mg GF @ ZIF-8, 2mg adsorbed 1.5mL900mg L, respectively^-1MG solution of (a). The adsorption time increased to 24h with increasing concentration. The adsorption rate of GF @ BSA membrane to MG remained low at 0.2%. The adsorption capacities of GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2 (respectively 556.3mg g) obtained by combination calculation^-1、447.8mg g^-1And 352.4mg g^-1) Binding to GF @ BSA (1.4mg g^-1) Adsorption capacity of (a) and a loading rate of ZIFs on a GF membrane. The final adsorption capacity of the ZIF loaded on the membrane was calculated to be 3965.1mg g each^-1、1538.2mg g^-1And 748.3mg g^-1。

TC is a common antibiotic in livestock and poultry farming. Here, similarly to the MG. 1mg GF @ BSA film, 1mg ZIF-8, 12mg GF @ ZIF-8, 1mg ZIF-L-1, 1.4mg GF @ ZIF-L-1, 1mg ZIF-L-2 and 1.9mg GF @ ZIF-L-2 for 1.5mL 80mg L^-1Adsorption of TC (b). After 24 hours, the intensity of the residual TC at 357nm was calculated, and as shown in FIG. 6, the GF @ BSA film showed almost no adsorption of TC (removal rate: 0.4%). Adsorption capacities of ZIFs (ZIF-8 powder and GF @ ZIF-8, ZIF-L-1 powder and GF @ ZIF-L-1, ZIF-L-2 powder and GF @ ZIF-L-2 powder) loaded on the ZIFs and GF @ ZIFs to TC were respectively 49.8mg g^-1And 193.4mg g^-1、99.5mg g^-1And 185.2mg g^-1And 100.6mg g^-1And 107.6mg g^-1. TC adsorption may be attributed to hydrogen bonding, electrostatic and pi-pi interactions.

4. Application of suction filtration membrane

To further understand the organic pest-collecting ability of the prepared membrane. As shown in fig. 7A, it is very important to rapidly collect harmful materials in the face of a large amount of water samples. Here, the prepared films (GF @ ZIF-8, GF @ ZIF-L-1, GF @ ZIF-L-2) were placed between metal clamps and flowed 30mg L from the top^-1And (7) MG. After 1 minute at a pressure of 0.8bar provided by a vacuum pump, the filtrate was collected and the absorbance value was measured and the removal rate was calculated. As shown in FIG. 7B, the results indicated that three membranes (GF @ ZIF-8, GF @ ZIF-L-1, GF @ ZIF-L-2) were paired with 10mL of 30mg L in 1min^-1The removal rates of MG were 78.3%, 59.0% and 46.4%, respectively. This indicates that the membrane can be used for rapid treatment of agricultural tests, food safety tests, water purification.

5. Stability in high temperature, organic solvents and alkaline solutions

In agricultural and industrial environments, membranes are subjected to unconventional environments, such as high temperatures or organic solvents and acidic or basic solutions, which result in a loss of the adsorption capacity of the membrane. Thus, the stability of the GF @ ZIFs membranes prepared was investigated, including the effects of hot water, chloroform and pH14 NaOH.

This process is similar to the adsorption performance of MG. Placing GF @ ZIF membrane (2mg GF @ BSA, 2.4mg GF @ ZIF-8, 2.8mg GF @ ZIF-L-1, 3.8mg GF @ ZIF-L-2) in a container containing 1mL 100mg L^-1Water and chloroform at 70 ℃. After 1 hour, the residual strength (OD value) of MG is shown in FIG. 8. The water treatment at the temperature of 70 ℃ is carried out,23.9%, 92.2%, 92.7% and 93.4% of MG were adsorbed by GF @ BSA, GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2, respectively. Noticeable fading can also be seen in the inserted digital photographs. Through the stability research in chloroform, the MG with the content of 11.7%, 86.5%, 80.9% and 66.1% can be respectively adsorbed by GF @ BSA, GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2. All these results demonstrate the high temperature, organic solvent resistance of the GF-ZIFs composite films, in comparison to GF @ BSA films.

SiO₂It cannot work in very high pH solutions, it will dissolve and form silicates. Here, the performance of the composite film in a high pH solution is investigated. Another dye, methyl orange (MO, stable in basic solution), was chosen. The same as in hot water and organic solvents.

As shown in FIG. 9, GF @ ZIFs membranes (2mg GF @ BSA, 2.4mg GF @ ZIF-8, 2.8mg GF @ ZIF-L-1, 3.8mg GF @ ZIF-L-2) were placed in a volume of 1mL of 20mg L^-1Dissolved in MO solution at pH14 NaOH and adsorbed for 1 hour. GF @ BSA, GF @ ZIF-8, GF @ ZIF-L-1 and GF @ ZIF-L-2 adsorbed 4.9%, 58.7%, 48.3% and 35.1% MO, respectively. GF @ BSA was gradually destroyed. The composite film is kept stable in alkaline solution, and the prepared ZIFs shell layer has a synergistic protection effect on the GF film.

All the results show that the stability of the bionic mineralized and grown GF @ ZIFs membrane can be used for collecting organic hazards in high-temperature water/organic solvent/alkaline solution.

Claims

1. A method for preparing a glass fiber-metal organic framework composite film is characterized by comprising the following steps: the method comprises the following steps:

1) modifying the cleaned glass fiber membrane by 3-aminopropyltriethoxysilane and glutaraldehyde step by step, and then crosslinking by using biomolecules after modification to obtain a biomolecule-modified glass fiber membrane;

2) dissolving the biomolecule-modified glass fiber membrane obtained in the step 1) in a metal ion A solution, then adding a ligand B solution for oscillation reaction, reacting the metal ion A solution and the ligand B solution on the biomolecule-modified glass fiber membrane to generate a metal organic framework material MOFs, and after the reaction is finished, sequentially cleaning and drying to obtain a glass fiber-metal organic framework composite film GF @ MOFs;

in the step 1), 3-aminopropyltriethoxysilane is diluted with acetone, and the volume ratio of the 3-aminopropyltriethoxysilane to the acetone is (1: 199) - (1: 4) (ii) a Diluting glutaraldehyde with deionized water, wherein the volume ratio of the glutaraldehyde to the water is (1: 199) - (1: 9); the biomolecule is dissolved in deionized water, and the concentration of the biomolecule is 0.5mg mL^-1-20mg mL^-1；

In the step 2), the metal ion A in the metal ion A solution is Zn²⁺、Co²⁺、Fe²⁺、Cu²⁺、Eu³⁺Or Tb³⁺(ii) a The ligand B in the ligand B solution is 2-methylimidazole, terephthalic acid or fumaric acid;

in the step 2), the biological molecules are proteins or polypeptides; the protein is bovine serum albumin, casein, lactalbumin, myoprotein, soy protein, gluten, gliadin, zein, glycinin, fibroin or fibrin.

2. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein: the glass fiber is glass fiber cloth, glass fiber yarn, hollow glass fiber tube or chopped glass fiber.

3. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein:

4. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein: in the step 1), the modification temperature of the 3-aminopropyltriethoxysilane is 4-40 ℃, and the modification time is 0.01-12 h.

5. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein: in the step 1), the modification temperature of the glutaraldehyde is 4-40 ℃, and the modification time is 0.01-4 h.

6. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein: in the step 1), the temperature for crosslinking the biomolecules is 4-40 ℃, and the time for crosslinking is 0.01-24 h.

7. The method of preparing a glass fiber-metal organic framework composite film according to claim 1, wherein: in the step 2), the reaction temperature is 4-40 ℃, and the reaction time is 0.01-24 h; the drying temperature is 40-60 deg.C, and the drying time is not less than 12 h.