A palygorskite clay material coated with a functional polymer of phenanthroline and its use

Abstract

The application discloses a palygorskite clay material coated with a phenanthroline functionalized polymer and application thereof, and first, a solution polymerization of glycidyl (meth)acrylate is initiated by a persulfate and a fatty tertiary amine redox initiation system, a polymer with an epoxy group in a side chain is grafted on a surface of a palygorskite nanorod crystal modified by a tertiary amine, then a 1,10-phenanthroline fluorescent chromophore is introduced into the grafted polymer side chain through an epoxy ring-opening reaction, and a palygorskite clay material coated with a phenanthroline functionalized polymer is prepared; the polymer-coated palygorskite nanocomposite provided by the application can be used for concentration detection and adsorption removal of copper ions in water.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polymer modification of the surface of nanoclay minerals, in particular to a palygorskite clay material coated with a functionalized polymer of phenanthroline and its application, which can be used for the detection and adsorption removal of copper ions in water. BACKGROUND

[0002] Transition metal copper is widely present in biology and environment, and is also an essential trace element for human body. With the continuous development of global industrialization, copper mining and smelting has produced a large amount of copper-containing wastewater discharge in the world, leading to pollution of water resources. The general methods for detecting copper and other metal ions include atomic absorption spectrophotometry, x-ray fluorescence spectrophotometry, and voltammetry. These methods are high in cost, long in time consumption, and inconvenient to operate. In comparison, the fluorescence probe method is not only convenient to operate but also high in sensitivity, and has been widely used in the detection of heavy metal ions in water medium.

[0003] The fluorescence probe method is a method for detecting by using a fluorescent substance to emit light under a specific excitation wavelength, and changing the fluorescence characteristics through interaction with the detected substance. At present, small molecule fluorescent probes are mainly used for fluorescence detection of heavy metal ion content. In addition, small molecule fluorescent probes can be modified on inorganic nanocarriers to prepare composite nanofluorescent probe materials. Compared with small molecule ion probes, composite nanofluorescent probe materials can not only be used for detecting the concentration of heavy metal ions in water, but also can adsorb and remove heavy metal ions in water, providing a new possibility for the detection and removal of heavy metal ions in wastewater. At the same time, these materials can be recovered and regenerated after application through desorption treatment, thereby reducing the cost and reducing environmental pollution. The detection and adsorption performance of composite nanofluorescent probe materials for heavy metal ions in water depends largely on the number of active sites (fluorescent chromophores).

[0004] Palygorskite clay, also known as attapulgite clay, is widely present in natural environment, has a special rod-shaped fibrous crystal structure, and is a kind of hydrous magnesium-aluminum silicate clay mineral with layered structure. This material has the advantages of cation exchangeability, water absorption, adsorption and decolorization, and large specific surface area. Moreover, this material is inexpensive and easy to obtain, and has been widely used in industry and agriculture. Palygorskite has a large number of hydroxyl groups on its surface, which can be used for chemical modification of the surface of materials. Palygorskite itself has non-fluorescent properties, so palygorskite clay can be used as a nanocarrier material for preparing nanofluorescent probes.

[0005] The present application develops a kind of surface coated with phenanthroline functional polymer palygorskite clay material, phenanthroline group has strong affinity to a variety of metal ions, can form stable complex. Meanwhile, phenanthroline is a strong fluorescent chromophore, can produce fluorescence change with specific metal ion combination, can be used for the fluorescence response of specific metal ion selectivity. Phenanthroline group can be bonded in surface grafted (meth) acrylate polymer side chain. Surface grafted polymer contains many repeat units, can significantly improve the coating amount of phenanthroline fluorescent chromophore. When copper ions exist in water body, fluorescence is significantly quenched. Therefore, the surface coated with phenanthroline functional polymer palygorskite clay can be used for copper ion detection, identification, solid phase extraction and enrichment separation in water. SUMMARY

[0006] The present application provides a kind of surface coated with phenanthroline functional polymer palygorskite clay material, palygorskite nanorod crystal surface grafts side chain (meth) acrylate polymer containing phenanthroline fluorescent chromophore, its structure is selected from one of general formula (I) or general formula (II):

[0007] General formula (I) General formula (II) Wherein, It refers to palygorskite nanorod crystal, x is the average polymerization degree of grafted monomer, R is selected from any one of hydrogen atom, methyl.

[0008] The present application further provides the preparation method of the above-mentioned surface coated with phenanthroline functional polymer palygorskite clay material, comprising the following steps:

[0009] Step one, hydrochloric acid pretreated palygorskite clay ATP is ultrasonically dispersed in organic solvent, and siloxane coupling agent (N,N-dimethyl-3-aminopropyl) trimethoxysilane is added, and refluxed with magnetic stirring for 12h;When cooled to room temperature, the product is centrifuged, the obtained solid is washed with ethanol, and vacuum dried to obtain palygorskite ATP-DATMS with surface modified tertiary amine group, and the above synthesis step reaction formula is expressed as follows:

[0010]

[0011] Step two, ATP-DATMS in step one is ultrasonically dispersed in organic solvent, and epoxy monomer is added, then ammonium persulfate initiator is added, vacuum is drawn, high-purity nitrogen is introduced, and the above operation is repeated for 3 times, then under the protection of nitrogen, magnetic stirring is carried out for 16-24h;When cooled to room temperature, the product is centrifuged, the obtained solid is washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80 DEG C for 24h to obtain palygorskite ATP-DATMS with surface grafted epoxy side group polymer, and the above synthesis step reaction formula is expressed as follows:

[0012]

[0013] Step three, the ATP-PGMA in step two is added into an organic solvent, after ultrasonic dispersion, any one of 2-amino-1,10-phenanthroline or 5-amino-1,10-phenanthroline is added, and heating is carried out to 100 DEG C for 24h under stirring; after cooling to room temperature, the product is centrifuged and separated, the obtained solid is washed twice with tetrahydrofuran and then washed twice with ethanol, and finally, vacuum drying is carried out at 80 DEG C for 24h to obtain the palygorskite nanocomposite ATP-PPA with phenanthroline fluorescent group side groups grafted on the surface, and according to the different positions of the amino substituent in the selected amino phenanthroline, the above synthesis steps are expressed as one of the following reaction formulae:

[0014]

[0015] Further, the organic solvent in step one is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, the volume of the organic solvent is 10-50 times the mass of the hydrochloric acid pretreated palygorskite ATP, and the mass of the (N,N-dimethyl-3-aminopropyl) trimethoxysilane is 0.5-2 times the mass of the hydrochloric acid pretreated palygorskite.

[0016] Further, the organic solvent in step two is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, the monomer is any one of glycidyl methacrylate and glycidyl acrylate, the volume of the organic solvent is 20-50 times the mass of the ATP-DATMS, the volume of the monomer is 5-15 times the mass of the ATP-DATMS, and the mass of the ammonium persulfate initiator is 10-20% of the mass of the ATP-DATMS.

[0017] The organic solvent in step three is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, the volume of the organic solvent is 50-100 times the mass of the ATP-PGMA, and the mass of the 2-amino-1,10-phenanthroline or 5-amino-1,10-phenanthroline is 0.5-2 times the mass of the ATP-PGMA.

[0018] The application further provides the application of the palygorskite clay material coated with the phenanthroline functionalized polymer to the detection and adsorption removal of copper ions in a water body.

[0019] The application has the following beneficial effects:

[0020] 1. Palygorskite clay is one of the main clay minerals in China, with abundant reserves. Palygorskite clay has rod-like morphology and natural nanostructure, with internal porous channels, large specific surface area and certain ion exchange capacity. Its surface is rich in hydroxyl groups, which is easy to be chemically modified. Therefore, palygorskite clay is known as "thousand soil king and ten thousand use soil".

[0021] 2. By using persulfate and tertiary amine initiation system, (meth) acrylate polymer containing epoxy group can be introduced on the surface of palygorskite rod-like fiber crystals. The surface grafted polymer has multiple repeating units, which can significantly increase the coating amount of phenanthroline fluorescent chromophore.

[0022] 3. The grafted phenanthroline group has strong affinity for many heavy metal ions and can form stable complexes with heavy metal ions. In particular, when forming a complex with copper ions, it will cause obvious fluorescence quenching phenomenon, so the phenanthroline group can be used as a fluorescence quenching probe material for recognizing copper ions. Therefore, the phenanthroline functional polymer coated on the surface of palygorskite clay crystals can be used for the detection, identification, solid phase extraction and enrichment separation of copper ions. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the description of the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 Transmission electron microscope photo of palygorskite ATP pretreated with hydrochloric acid used in Example 1;

[0025] Figure 2 Transmission electron microscope photo of ATP-PPA(I)-1 prepared in Example 1;

[0026] Figure 3 Thermogravimetric analysis chart of ATP-DATMS-1, ATP-PGMA-1, ATP-PPA(I)-1 and palygorskite ATP pretreated with hydrochloric acid prepared in Example 1;

[0027] Figure 4 Infrared absorption spectrum chart of ATP-DATMS-1, ATP-PGMA-1, ATP-PPA(I)-1 prepared in Example 1;

[0028] Figure 5 Fluorescence emission spectrum chart of ATP-PPA(I)-1 prepared in Example 1 at different copper ion concentrations;

[0029] Figure 6 The adsorption amount curve of ATP-PPA(I)-1 prepared in Example 1 for different initial concentrations of copper ions. DETAILED DESCRIPTION

[0030] In order to further reveal the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0031] Example 1:

[0032] (I) 2.0 g of palygorskite ATP pretreated with hydrochloric acid was ultrasonically dispersed in 100 mL of anhydrous ethanol, and 4.0 g of (N,N-dimethyl-3-aminopropyl) trimethoxysilane was added, and refluxed with magnetic stirring for 12 h; after cooling to room temperature, the product was centrifuged and separated, and the obtained solid was washed with ethanol and vacuum dried to obtain palygorskite ATP-DATMS-1 with surface modified tertiary amine groups.

[0033] (II) 1.0 g of ATP-DATMS-1 in step (I) was ultrasonically dispersed in 50 mL of N,N-dimethylformamide, and 10 mL of glycidyl methacrylate monomer was added, followed by the addition of 0.15 g of ammonium persulfate initiator, vacuum was drawn, high-purity nitrogen was introduced, and this operation was repeated for 3 times, and then the reaction was carried out under nitrogen protection with magnetic stirring for 24 h; after cooling to room temperature, the product was centrifuged and separated, and the obtained solid was washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80°C for 24 h to obtain palygorskite ATP-PGMA-1 with surface grafted epoxy side group-containing polymers.

[0034] (III) 1.0 g of ATP-PGMA-1 in step (II) was added to 75 mL of N,N-dimethylformamide, ultrasonically dispersed, and then 1.0 g of 5-amino-1,10-phenanthroline was added, and the reaction was carried out with continuous stirring at 100°C for 24 h; after cooling to room temperature, the product was centrifuged and separated, and the obtained solid was washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80°C for 24 h to obtain palygorskite nanocomposite ATP-PPA(I)-1 with surface grafted phenanthroline fluorescent group-containing side group polymers, and the structural formula is as follows:

[0035]

[0036] Example 2:

[0037] (One) 2.0 g of the attapulgite ATP pretreated with hydrochloric acid was ultrasonically dispersed in 20 mL of anhydrous dioxane, and 2.0 g of (N,N-dimethyl-3-aminopropyl) trimethoxysilane was added, and refluxed with magnetic stirring for 12 h; after cooling to room temperature, the product was centrifuged and separated, the obtained solid was washed with ethanol, and vacuum dried to obtain the attapulgite ATP-DATMS-2 modified with tertiary amine groups on the surface.

[0038] (Two) 1.0 g of the ATP-DATMS-2 in step (One) was ultrasonically dispersed in 20 mL of anisole, and 5 mL of glycidyl methacrylate monomer was added, followed by the addition of 0.1 g of ammonium persulfate initiator, vacuumed, and high-purity nitrogen was introduced, and this operation was repeated 3 times, and then reacted with magnetic stirring under nitrogen protection for 16 h; after cooling to room temperature, the product was centrifuged and separated, the obtained solid was washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80°C for 24 h to obtain the attapulgite ATP-PGMA-2 grafted with epoxy side group-containing polymers on the surface.

[0039] (Three) 1.0 g of the ATP-PGMA-1 in step (Two) was added to 50 mL of toluene, ultrasonically dispersed, and then 0.5 g of 2-amino-1,10-phenanthroline was added, and heated to 100°C for continuous stirring reaction for 24 h; after cooling to room temperature, the product was centrifuged and separated, the obtained solid was washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80°C for 24 h to obtain the attapulgite nanocomposite ATP-PPA(II)-2 grafted with phenanthroline fluorescent group-containing side group polymers on the surface, and the structure is as follows:

[0040]

[0041] Example 3:

[0042] (One) 2.0 g of the attapulgite ATP pretreated with hydrochloric acid was ultrasonically dispersed in 80 mL of anhydrous acetonitrile, and 1.0 g of (N,N-dimethyl-3-aminopropyl) trimethoxysilane was added, and refluxed with magnetic stirring for 12 h; after cooling to room temperature, the product was centrifuged and separated, the obtained solid was washed with ethanol, and vacuum dried to obtain the attapulgite ATP-DATMS-3 modified with tertiary amine groups on the surface.

[0043] (Two) 1.0 g of the ATP-DATMS-3 in step (One) was ultrasonically dispersed in 40 mL of dioxane, and 15 mL of glycidyl acrylate monomer was added, followed by the addition of 0.2 g of ammonium persulfate initiator, vacuumed, and high-purity nitrogen was introduced, and this operation was repeated 3 times, and then reacted with magnetic stirring under nitrogen protection for 20 h; after cooling to room temperature, the product was centrifuged and separated, the obtained solid was washed with tetrahydrofuran for 2 times and then washed with ethanol for 2 times, and finally vacuum dried at 80°C for 24 h to obtain the attapulgite ATP-PGMA-3 grafted with epoxy side group-containing polymers on the surface.

[0044] (III) 1.0 g of ATP-PGMA-3 from step (II) was added to 100 mL of anisole, and after ultrasonic dispersion, 2.0 g of 5-amino-1,10-phenanthroline was added, and the mixture was heated to 100° C. and stirred for 24 h. After cooling to room temperature, the product was centrifuged, and the resulting solid was washed twice with tetrahydrofuran and then twice with ethanol, and finally dried in vacuo at 80° C. for 24 h to obtain a palygorskite nanocomposite material ATP-PPA(I)-3 with a surface-grafted polymer containing a phenanthroline fluorescent group side group, the structural formula of which is as follows:

[0045]

[0046] Specific detection:

[0047] 1. Compare the transmission electron micrograph of ATP-PPA(I)-1 of Example 1 with that of the original palygorskite. Figure 1 As shown in Figure 2, the original palygorskite presents a loose rod-like structure with a diameter of about 15 to 25 nm. Figure 2 As shown in the transmission electron microscopy image of ATP-PPA(I)-1, the rod-shaped crystal structure of palygorskite becomes blurred, cross-linked and agglomerated, and it can be seen that the rod-shaped crystals are coated with polymers.

[0048] 2. Figure 3 Thermogravimetric analysis diagrams of ATP-DATMS-1, ATP-PGMA-1, ATP-PPA(I)-1 and hydrochloric acid pretreated palygorskite ATP prepared in Example 1. The temperature-increasing thermogravimetric analysis curve of ATP shows that the weight decreases slowly and slightly after heating. When the ATP sample is heated to 800°C, the weight loss is 10.5%, and the weight loss is mainly caused by the evaporation of adsorbed water and structural water at high temperature. At 800°C, the final weight loss rates of ATP-DATMS-1, ATP-PGMA-1 and ATP-PPA(I)-1 are 14.9%, 26.6% and 29.8% weight loss, respectively. It can be seen that with the increase of the modification steps, the thermal weight loss of the material also increases, indicating that each modification step increases the content of organic components in the material.

[0049] 3. Figure 4 The infrared absorption spectra of ATP-DATMS-1, ATP-PGMA-1 and ATP-PPA(I)-1 prepared in Example 1 are shown. In the infrared absorption spectrum of ATP-DATMS-1, the wavelengths at 2923 and 2855 cm - 1The weak absorption peak belongs to the stretching vibration peak of the carbon chain CH bond in the introduced siloxane coupling agent. After poly(glycidyl methacrylate) was grafted on the surface of the material using surface-initiated polymerization, ATP-PGMA-1 was detected at 912 cm -1The peaks at 1730 cm -1 The peaks at 1730 cm -1 The peaks at 1730 cm -1 The peaks at 1730 cm -1 The peaks at 1730 cm

[0050] 4. Figure 5 The fluorescence emission spectra of ATP-PPA(I)-1 prepared in Example 1 at different concentrations of Cu(II) ions. The temperature was 25℃, the concentration of ATP-PPA(I)-1 nanoparticles in water was 0.01 mg / mL, the pH value of the solution was 6.0, and the excitation wavelength was 275 nm. It can be seen that the fluorescence emission intensity of ATP-PPA(I)-1 dispersion continuously decreases as the concentration of Cu(II) ions increases from 0 mg / L to 0.12 mg / L, while the shape of the emission band remains basically unchanged in these spectra. Finally, the fluorescence of ATP-PPA(I)-1 dispersion in water is completely quenched. Therefore, ATP-PPA(I)-1 can be used as a fluorescence probe for detecting Cu(II) ions.

[0051] 5. Figure 6 The adsorption capacity curve of ATP-PPA(I)-1 prepared in Example 1 for different initial concentrations of copper ions. The temperature was 25℃, the concentration of ATP-PPA(I)-1 nanoparticles in water was 0.1 mg / mL, the initial pH value of the solution was 6.0, and the adsorption time was 12 h. It can be seen that the equilibrium adsorption capacity of the material for copper ions increases as the concentration of copper ions increases, because the driving force of concentration gradient is increasing. When the initial concentration of copper ions is 160 mg / L, the equilibrium adsorption capacity of ATP-PPA(I)-1 for copper ions reaches 35.6 mg / g. Therefore, ATP-PPA(I)-1 has a certain ability to adsorb and remove copper ions.

[0052] The above results show that the multifunctional nanocomposite material ATP-PPA(I)-1 prepared in Example 1 can be used for detecting and adsorbing and removing copper ions in water.

[0053] The above only describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A palygorskite clay material coated with a phenanthroline functionalized polymer, wherein a (meth)acrylate polymer containing a phenanthroline fluorescent chromophore as a side chain is grafted onto the surface of the palygorskite nanorod-shaped crystals, wherein the structure of the polymer is selected from one of the general formulas (I) or (II): General formula (I) ; General formula (II) ; in, refers to palygorskite nanorod-shaped crystals, x is the average degree of polymerization of the grafted monomer, and R is selected from any one of a hydrogen atom and a methyl group; The preparation method comprises the following steps: Step 1: ultrasonically disperse the hydrochloric acid pretreated palygorskite clay ATP in an organic solvent, add a siloxane coupling agent (N,N-dimethyl-3-aminopropyl)trimethoxysilane, and reflux under magnetic stirring for 12 hours; after cooling to room temperature, the product is centrifuged, and the resulting solid is washed with ethanol and vacuum dried to obtain palygorskite ATP-DATMS with a surface modified tertiary amine group. The above synthesis steps are expressed as follows: ； Step 2: Ultrasonic dispersion of ATP-DATMS in step 1 in an organic solvent, and adding epoxy monomer, followed by adding ammonium persulfate initiator, vacuuming, introducing high-purity nitrogen, repeating this operation three times, and reacting under nitrogen protection with magnetic stirring for 16 to 24 hours; after cooling to room temperature, the product was centrifuged, and the obtained solid was washed twice with tetrahydrofuran and then twice with ethanol, and finally heated at 80 o C vacuum drying for 24 hours to obtain palygorskite ATP-DATMS with epoxy side group-containing polymer grafted on the surface. The above synthesis steps are expressed as follows: ； Step 3: Add ATP-PGMA prepared in step 2 to an organic solvent, disperse it by ultrasonication, and then add either 2-amino-1,10-phenanthroline or 5-amino-1,10-phenanthroline. Heat to 100°C and continue stirring to react for 24 hours. After cooling to room temperature, centrifuge the product, wash the solid twice with tetrahydrofuran and then with ethanol, and finally heat at 80 o C vacuum drying for 24 hours to obtain a palygorskite nanocomposite material ATP-PPA with a surface-grafted polymer containing a phenanthroline fluorescent group side group. Depending on the position of the amino substituent in the aminophenanthroline, the above synthesis steps can be expressed as one of the following reaction formulas: ； or 。 2. The palygorskite clay material having a surface coated with a phenanthroline functionalized polymer according to claim 1, wherein: The organic solvent in step 1 is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, and the volume of the organic solvent is 10 to 50 times the mass of the hydrochloric acid pretreated palygorskite, and the mass of the (N,N-dimethyl-3-aminopropyl) trimethoxysilane is 0.5 to 2 times the mass of the hydrochloric acid pretreated palygorskite ATP.

3. The palygorskite clay material having a surface coated with a phenanthroline functionalized polymer according to claim 1, wherein: In step 2, the organic solvent is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, the monomer is any one of glycidyl methacrylate and glycidyl acrylate, the volume usage of the organic solvent is 20 to 50 times the mass of ATP-DATMS, the volume usage of the monomer is 5 to 15 times the mass of ATP-DATMS, and the mass of the ammonium persulfate initiator is 10 to 20% of the mass of ATP-DATMS.

4. The palygorskite clay material having a surface coated with a phenanthroline functionalized polymer according to claim 1, wherein: In step 3, the organic solvent is selected from any one of acetone, ethanol, toluene, anisole, xylene, tetrahydrofuran, dioxane, acetonitrile and N,N-dimethylformamide, the volume of the organic solvent is 50 to 100 times the mass of ATP-PGMA, and the mass of the 2-amino-1,10-phenanthroline or 5-amino-1,10-phenanthroline is 0.5 to 2 times the mass of ATP-PGMA.

5. The palygorskite clay material having a surface coated with a phenanthroline functionalized polymer according to claim 1, wherein: The polymer-coated palygorskite nanocomposite material can be used for concentration detection and adsorption removal of copper ions in water.

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