Modified single-walled carbon nanotube-containing material and preparation method thereof

Abstract

The invention discloses a material containing a modified single-walled carbon nanotube. The material comprises the modified single-walled carbon nanotube and modified fluorocarbon doped hydroxyapatite. The invention also discloses a preparation method of the material containing the modified single-walled carbon nanotube, which comprises the following steps: adding the modified single-walled carbon nanotube into a Ca (NO3) 2.4 H2O solution, performing ultrasonic treatment for 40-60 minutes at the temperature of 30-40 DEG C, stirring for 10-30 minutes, and adding a mixed solution of (NH4) 2HPO4, NH4F and (NH4) 2CO3 to prepare the material containing the modified single-walled carbon nanotube. F-hydroxyapatite is synthesized by adopting a chemical precipitation method which is simple to operate and low in cost, and is loaded on industrial carbon nanotubes modified by mixed acid in a non-covalent binding manner to obtain the composite material with high dispersity and excellent Mn (II) adsorption performance, and the composite material is decomposed or evaporated by adopting pore-foaming agents (NH4) 2CO3 and NH4Cl at high temperature, so that the Mn (II) adsorption performance is improved. And micropores are reserved in the HAP, so that the purpose of increasing the specific surface area is achieved, and the adsorption capacity is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of single-walled carbon nanotube materials, and in particular relates to a material containing modified single-walled carbon nanotubes and a preparation method thereof. Background Art

[0002] The main reasons for excessive manganese concentration in water bodies are the mining and processing of manganese ore, the illegal discharge of pollutants from factories, and the dissolution of manganese-containing minerals in aquifers caused by environmental changes. The electrolytic manganese slag (EMR) produced in the electrolytic manganese process releases manganese-containing acidic leachate under the action of rainfall leaching. The filtrate migrates with rainfall infiltration and surface runoff, leading to manganese pollution in the ecosystem. In addition, sediments in water bodies will also release manganese into the water due to water disturbance and changes in redox conditions. The maximum concentration of manganese in drinking water for human consumption should not exceed 0.05 mg / L. A certain concentration of manganese is necessary and beneficial to organisms. However, higher concentrations of manganese can cause irreversible damage to the nervous system, heart, lungs, liver, etc. of animals, and can also affect the photosynthesis of plants.

[0003] Nanomaterials have been proven to be able to remove heavy metal ions and other pollutants efficiently and quickly, thanks to their high specific surface area, high surface activity and porosity. Atomic level modification, surface grafting and other technologies provide more possibilities for the modification of nanomaterials. Carbon nanotubes, as a hollow tubular nanomaterial composed entirely of carbon atoms, have the characteristics of low density, chemical inertness, reusability and excellent mechanical properties. They are one of the most promising nano-adsorbent materials due to their low synthesis and purification costs.

[0004] Hydroxyapatite (HA or HAP for short) has a molecular formula of Ca 10 (PO4)6(OH)2 is a white or off-white powder or block, stable under alkaline conditions; slightly soluble in water under neutral conditions, the pH of the aqueous solution is usually in the range of 7-9; unstable under acidic conditions. HAP is an excellent adsorption material and can be used for heavy metals (such as Cd 2+ , Pb 2+ Cr 2+ , Cu 2+ etc.), organic dyes (such as methylene blue), inorganic anions (such as F - , dichromate, borate, arsenate and other pollutants.

[0005] The present application improves the adsorption of heavy metal ions in water by composite modified carbon nanotubes and hydroxyapatite. Summary of the invention

[0006] The object of the present invention is to provide a material containing modified single-walled carbon nanotubes and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a material containing modified single-walled carbon nanotubes, including modified single-walled carbon nanotubes and modified fluorocarbon-doped hydroxyapatite.

[0008] Preferably, the method for preparing the modified single-walled carbon nanotubes comprises the following steps:

[0009] S11: pretreatment of single-walled carbon nanotubes;

[0010] S12: adding the treated single-walled carbon nanotubes into the mixed acid and letting it stand for 1-2 hours;

[0011] S13: under alkaline conditions, add bromoacetic acid and place in an ultrasonic cleaning apparatus for water bath ultrasonication;

[0012] S14: After the production is completed, the mixed solution is filtered through a 0.11-0.28 μm filter membrane, and the obtained product is washed to a pH of 7;

[0013] S15: washing away the residual water with anhydrous ethanol, and drying at 70-100° C. for 20-30 h to obtain modified single-walled carbon nanotubes.

[0014] Preferably, in any of the above schemes, in step S11, the specific operation of the pre-treatment is to dry the single-walled carbon nanotubes at 70-100° C. for 12-36 hours.

[0015] Preferably, in any of the above schemes, in step S12, the mixed acid includes concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 2-4:1-3.

[0016] Preferably, in any of the above schemes, in step S13, the temperature of the ultrasonic cleaning instrument is 30-50° C., and the ultrasonic time is 3-5 h.

[0017] Preferably, in any of the above schemes, the method for preparing the modified fluorocarbon-doped hydroxyapatite comprises the following steps:

[0018] S21: Prepare Ca(NO3)2·4H2O solution and (NH4)2HPO4 solution respectively;

[0019] S22: At 30-40°C, under stirring, first mix the (NH4)2HPO4 solution with the NH4F solution, then drip the mixed solution into the Ca(NO3)2·4H2O solution at a flow rate of 4 mL / min, add concentrated ammonia water to adjust the pH to 9-11, let stand for 30-50 min, and then add (NH4)2CO3 and NH4Cl;

[0020] S23: The mixed solution is quickly transferred to a microwave oven and heated with a microwave / light wave combination for 15-20 minutes, and then centrifuged while hot, washed with pure water until it is nearly neutral, and excess water is washed with ethanol, and dried at 80-100°C for 24 hours to obtain modified fluorocarbon-doped hydroxyapatite.

[0021] Preferably, in any of the above schemes, in step S21, the Ca(NO3)2·4H2O solution is 0.015-0.030 mol / L, and the (NH4)2HPO4 solution is 0.02-0.03 mol / L.

[0022] In any of the above schemes, preferably, in step S22, the NH4F solution is 0.02-0.04 mol / L, and the amount of NH4F solution added is based on F - Replace OH - Content 80-100%.

[0023] Preferably, in any of the above schemes, in step S22, the volume ratio of the (NH4)2HPO4 to the (NH4)2HPO4 solution is 1:1.5-2.

[0024] A method for preparing a material containing modified single-walled carbon nanotubes comprises the following steps:

[0025] The modified single-walled carbon nanotubes are added into a Ca(NO3)2·4H2O solution, ultrasonicated for 40-60 minutes and then stirred for 10-30 minutes at 30-40°C, and a mixed solution of (NH4)2HPO4, NH4F and (NH4)2CO3 is added to obtain a material containing modified single-walled carbon nanotubes.

[0026] Technical effects and advantages of the present invention: The present invention adopts a simple and low-cost chemical precipitation method to synthesize F - The hydroxyapatite was loaded on industrial-grade carbon nanotubes modified by mixed acid in a non-covalent manner to obtain a composite material with high dispersibility and excellent Mn(II) adsorption performance. The porogens (NH4)2CO3 and NH4Cl were decomposed or evaporated at high temperature to leave micropores inside the HAP, thereby increasing the specific surface area and making the adsorption capacity stronger. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] Embodiment 1:

[0029] The invention provides a modified single-walled carbon nanotube material, comprising modified single-walled carbon nanotubes and modified fluorocarbon-doped hydroxyapatite.

[0030] The preparation method of modified single-walled carbon nanotubes comprises the following steps:

[0031] S11: pretreatment of the single-walled carbon nanotubes, specifically drying the single-walled carbon nanotubes at 70° C. for 12 h;

[0032] S12: adding the treated single-walled carbon nanotubes into a mixed acid and letting it stand for 1 hour, wherein the mixed acid includes concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 2:1;

[0033] S13: under alkaline conditions, add bromoacetic acid, place in an ultrasonic cleaner for water bath ultrasonication, the temperature of the ultrasonic cleaner is 30° C., and the ultrasonication time is 3 h;

[0034] S14: After the production is completed, the mixed solution is filtered through a 0.11 μm filter membrane, and the obtained product is washed to a pH of 7;

[0035] S15: washing away the residual water with anhydrous ethanol, and drying at 70° C. for 20 h to obtain modified single-walled carbon nanotubes.

[0036] The preparation method of modified fluorocarbon-doped hydroxyapatite comprises the following steps:

[0037] S21: Prepare Ca(NO3)2·4H2O solution and (NH4)2HPO4 solution respectively, the Ca(NO3)2·4H2O solution is 0.015mol / L, and the (NH4)2HPO4 solution is 0.02mol / L;

[0038] S22: At 30-40°C, under stirring, firstly mix (NH4)2HPO4 solution with NH4F solution, wherein the NH4F solution is 0.02 mol / L, and the amount of NH4F solution added is according to F - Replace OH - The content is 80%, and then the mixed solution is dripped into the Ca(NO3)2·4H2O solution at a flow rate of 4mL / min, the volume ratio of (NH4)2HPO4 to (NH4)2HPO4 solution is 1:1.5, concentrated ammonia is added to adjust the pH to 9, and the mixture is allowed to stand for 30min, and then the mixture of (NH4)2CO3 and NH4Cl is added, and the volume ratio of the mixture of (NH4)2CO3 and NH4Cl to the mixture of (NH4)2HPO4 and NH4F is maintained at 1:1;

[0039] S23: The mixed solution was quickly transferred to a microwave oven and heated with a microwave / light wave combination for 15 minutes, and then centrifuged while hot. The mixed solution was washed with pure water until it was nearly neutral, and excess water was washed with ethanol. The mixed solution was dried at 80°C for 24 hours to obtain modified fluorocarbon-doped hydroxyapatite.

[0040] Embodiment 2:

[0041] The invention provides a modified single-walled carbon nanotube material, comprising modified single-walled carbon nanotubes and modified fluorocarbon-doped hydroxyapatite.

[0042] The preparation method of modified single-walled carbon nanotubes comprises the following steps:

[0043] S11: pretreatment of the single-walled carbon nanotubes, specifically drying the single-walled carbon nanotubes at 80° C. for 24 hours;

[0044] S12: adding the treated single-walled carbon nanotubes into a mixed acid and letting it stand for 1 hour, wherein the mixed acid includes concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 3:1;

[0045] S13: under alkaline conditions, add bromoacetic acid, place in an ultrasonic cleaner for water bath ultrasonication, the temperature of the ultrasonic cleaner is 40° C., and the ultrasonication time is 4 h;

[0046] S14: After the production is completed, the mixed solution is filtered through a 0.19 μm filter membrane, and the obtained product is washed to a pH of 7;

[0047] S15: washing away the residual water with anhydrous ethanol, and drying at 90° C. for 25 h to obtain modified single-walled carbon nanotubes.

[0048] The preparation method of modified fluorocarbon-doped hydroxyapatite comprises the following steps:

[0049] S21: Prepare Ca(NO3)2·4H2O solution and (NH4)2HPO4 solution respectively, the Ca(NO3)2·4H2O solution is 0.015-0.030mol / L, and the (NH4)2HPO4 solution is 0.025mol / L;

[0050] S22: At 40°C, under stirring, firstly, (NH4)2HPO4 solution and NH4F solution were mixed, wherein the NH4F solution was 0.03 mol / L, and the amount of NH4F solution added was according to F - Replace OH -The content is 90%, and then the mixed solution is dripped into the Ca(NO3)2·4H2O solution at a flow rate of 4mL / min, the volume ratio of (NH4)2HPO4 to (NH4)2HPO4 solution is 1:2, concentrated ammonia is added to adjust the pH to 10, and the mixture is allowed to stand for 40min, and then the mixture of (NH4)2CO3 and NH4Cl is added, and the volume ratio of the mixture of (NH4)2CO3 and NH4Cl to the mixture of (NH4)2HPO4 and NH4F is maintained at 1:1;

[0051] S23: The mixed solution was quickly transferred to a microwave oven and heated with a microwave / light wave combination for 18 minutes, and then centrifuged while hot. The mixed solution was washed with pure water until it was nearly neutral, and excess water was washed with ethanol. The mixed solution was dried at 90°C for 24 hours to obtain modified fluorocarbon-doped hydroxyapatite.

[0052] Embodiment 3:

[0053] The invention provides a modified single-walled carbon nanotube material, comprising modified single-walled carbon nanotubes and modified fluorocarbon-doped hydroxyapatite.

[0054] The preparation method of modified single-walled carbon nanotubes comprises the following steps:

[0055] S11: pretreatment of the single-walled carbon nanotubes, specifically drying the single-walled carbon nanotubes at 100° C. for 36 hours;

[0056] S12: adding the treated single-walled carbon nanotubes into a mixed acid and letting it stand for 2 hours, wherein the mixed acid includes concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 4:3;

[0057] S13: under alkaline conditions, add bromoacetic acid, place in an ultrasonic cleaner for water bath ultrasound, the temperature of the ultrasonic cleaner is 50° C., and the ultrasound time is 5 h;

[0058] S14: After the production is completed, the mixed solution is filtered through a 0.28 μm filter membrane, and the obtained product is washed to a pH of 7;

[0059] S15: washing away the residual water with anhydrous ethanol, and drying at 100° C. for 30 h to obtain modified single-walled carbon nanotubes.

[0060] The preparation method of modified fluorocarbon-doped hydroxyapatite comprises the following steps:

[0061] S21: Prepare Ca(NO3)2·4H2O solution and (NH4)2HPO4 solution respectively, the Ca(NO3)2·4H2O solution is 0.030mol / L, and the (NH4)2HPO4 solution is 0.03mol / L;

[0062] S22: At 40°C, under stirring, firstly, (NH4)2HPO4 solution and NH4F solution were mixed, wherein the NH4F solution was 0.04 mol / L, and the amount of NH4F solution added was according to F - Replace OH - The content is 100%, and then the mixed solution is dripped into the Ca(NO3)2·4H2O solution at a flow rate of 4mL / min, the volume ratio of (NH4)2HPO4 to (NH4)2HPO4 solution is 1:1.5, concentrated ammonia is added to adjust the pH to 11, and the mixture is allowed to stand for 50min, and then the mixture of (NH4)2CO3 and NH4Cl is added, and the volume ratio of the mixture of (NH4)2CO3 and NH4Cl to the mixture of (NH4)2HPO4 and NH4F is maintained at 1:1;

[0063] S23: The mixed solution was quickly transferred to a microwave oven and heated with a microwave / light wave combination for 20 minutes, and then centrifuged while hot, washed with pure water until it was nearly neutral, and excess water was washed away with ethanol, and dried at 100°C for 24 hours to obtain modified fluorocarbon-doped hydroxyapatite.

[0064] Embodiment 4:

[0065] A method for preparing a material containing modified single-walled carbon nanotubes comprises the following steps:

[0066] The modified single-walled carbon nanotubes were added into a Ca(NO3)2·4H2O solution, wherein the amount of the modified single-walled carbon nanotubes added was 1% of the total mass of all solid reagents added. The solution was ultrasonicated for 40-60 minutes and then stirred for 10-30 minutes at 30-40°C. A mixed solution of (NH4)2HPO4, NH4F and (NH4)2CO3 was added to make n(Ca:P:C:F)51.5:0.8:0.2:0.18, thereby obtaining a material containing modified single-walled carbon nanotubes.

[0067] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A material containing modified single-walled carbon nanotubes, characterized in that: include Modified single-walled carbon nanotubes and modified fluorocarbon-doped hydroxyapatite.

2. The modified single-walled carbon nanotube material according to claim 1, characterized in that: The method for preparing the modified single-walled carbon nanotubes comprises the following steps: S11: pretreatment of single-walled carbon nanotubes; S12: adding the treated single-walled carbon nanotubes into the mixed acid and letting it stand for 1-2 hours; S13: under alkaline conditions, add bromoacetic acid and place in an ultrasonic cleaning apparatus for water bath ultrasonication; S14: After the production is completed, the mixed solution is filtered through a 0.11-0.28 μm filter membrane, and the obtained product is washed to a pH of 7; S15: washing away the residual water with anhydrous ethanol, and drying at 70-100° C. for 20-30 h to obtain modified single-walled carbon nanotubes.

3. The modified single-walled carbon nanotube material according to claim 3, characterized in that: In step S11, the specific operation of the pre-treatment is to dry the single-walled carbon nanotubes at 70-100°C for 12-36 hours.

4. The modified single-walled carbon nanotube material according to claim 3, characterized in that: In step S12, the mixed acid includes concentrated sulfuric acid and concentrated nitric acid, and the volume ratio of the concentrated sulfuric acid to the concentrated nitric acid is 2-4:1-3.

5. The modified single-walled carbon nanotube material according to claim 3, characterized in that: In step S13, the temperature of the ultrasonic cleaning instrument is 30-50°C, and the ultrasonic time is 3-5h.

6. The modified single-walled carbon nanotube material according to claim 1, characterized in that: The preparation method of the modified fluorocarbon-doped hydroxyapatite comprises the following steps: S21: Prepare Ca(NO3)2·4H2O solution and (NH4)2HPO4 solution respectively; S22: At 30-40°C, under stirring, first mix the (NH4)2HPO4 solution with the NH4F solution, then drip the mixed solution into the Ca(NO3)2·4H2O solution at a flow rate of 4 mL / min, add concentrated ammonia water to adjust the pH to 9-11, let stand for 30-50 min, and then add (NH4)2CO3 and NH4Cl; S23: The mixed solution is quickly transferred to a microwave oven and heated with a microwave / light wave combination for 15-20 minutes, and then centrifuged while hot, washed with pure water until it is nearly neutral, and excess water is washed with ethanol, and dried at 80-100°C for 24 hours to obtain modified fluorocarbon-doped hydroxyapatite.

7. The modified single-walled carbon nanotube material according to claim 6, characterized in that: In step S21, the Ca(NO3)2·4H2O solution is 0.015-0.030 mol / L, and the (NH4)2HPO4 solution is 0.02-0.03 mol / L.

8. The modified single-walled carbon nanotube material according to claim 6, characterized in that: In step S22, the NH4F solution is 0.02-0.04 mol / L, and the amount of NH4F solution added is based on F - Replace OH - Content 80-100%.

9. The modified single-walled carbon nanotube material according to claim 6, characterized in that: In step S22, the (NH4)2HPO 4与 The volume ratio of (NH4)2HPO4 solution is 1:1.5-2.

10. A method for preparing a material containing modified single-walled carbon nanotubes according to any one of claims 1 to 9, characterized in that: The following steps are involved: The modified single-walled carbon nanotubes are added into a Ca(NO3)2·4H2O solution, ultrasonicated for 40-60 minutes and then stirred for 10-30 minutes at 30-40°C, and a mixed solution of (NH4)2HPO4, NH4F and (NH4)2CO3 is added to obtain a material containing modified single-walled carbon nanotubes.