Method for preparing high purity carbon quantum dots by using microwave method

A technology of carbon quantum dots and microwave method, which is applied in the direction of nanocarbon, nanotechnology for materials and surface science, nanotechnology, etc., to achieve the effect of reducing environmental pressure, easy operation and ensuring uniformity

Inactive Publication Date: 2014-02-19
张岐
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Aiming at the shortcomings of the existing microwave method, the present invention technically uses a microwave reactor to replace the traditional microwave oven. In the microwave process, the macromolecular raw materials are microwaved in two stages under certain conditions, and the first microwave is used to tre

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  • Method for preparing high purity carbon quantum dots by using microwave method
  • Method for preparing high purity carbon quantum dots by using microwave method
  • Method for preparing high purity carbon quantum dots by using microwave method

Examples

Experimental program
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Effect test

Embodiment 1

[0032] (1) The deacetylation degree of 2.0g is 98%, and the molecular weight distribution index (M w / M n ) of 1.20 chitosan powder was dissolved in 120mL of acetic acid (HAc) solution with a mass concentration of 0.5%, and 1.2mL of hydrogen peroxide (H 2 o 2 ), stirred at normal temperature for 5 minutes to form a uniform and transparent colorless viscous liquid;

[0033] (2) Place the viscous liquid above in a microwave reactor (model: HKWB-10RB) for microwave degradation. The parameters are set as follows: microwave power 700W, temperature 80°C, microwave time 70 minutes, colorless viscous liquid Become a uniform transparent light yellow liquid;

[0034] (3) Put the above-mentioned uniform and transparent light yellow liquid in a microwave reactor (model: HKWB-10RB) to continue the reaction, and reset the microwave parameters. The parameters are set as follows: microwave power 900W, temperature 110°C, microwave time 70 minutes, increase Microwave power and reaction temp...

Embodiment 2

[0039] (1) The deacetylation degree of 2.0g is 98%, and the molecular weight distribution index (M w / M n ) is 1.24 chitosan powder dissolved in 180mL mass concentration of 30% hydrochloric acid (HCl) solution, and add 6mL of hydrogen peroxide (H 2 o 2 ), stirred at normal temperature for 20 minutes, forming a uniform and transparent colorless viscous liquid;

[0040] (2) Place the viscous liquid above in a microwave reactor (model: HKWB-10RB) for microwave degradation. The parameters are set as follows: microwave power 800W, temperature 100°C, microwave time 120 minutes, colorless viscous liquid Become a uniform transparent light yellow liquid;

[0041] (3) Put the above uniform and transparent light yellow liquid in a microwave reactor (model: HKWB-10RB) to continue the reaction, reset the microwave parameters, the parameters are set as follows: microwave power 1100W, temperature 300°C, microwave time 120 minutes, increase Microwave power and reaction temperature, open t...

Embodiment 3

[0046] (1) The deacetylation degree of 3.0g is 95%, the molecular weight distribution index (M w / M n ) is 1.17 chitosan powder dissolved in 180mL of nitric acid (HNO 3 ) solution, and add 6mL of hydrogen peroxide (H 2 o 2 ), stirred at normal temperature for 10 minutes to form a uniform and transparent colorless viscous liquid;

[0047] (2) Place the viscous liquid above in a microwave reactor (model: HKWB-10RB) for microwave degradation. The parameters are set as follows: microwave power 800W, temperature 70°C, microwave time 50 minutes, colorless viscous liquid Become a uniform transparent light yellow liquid;

[0048] (3) Put the above-mentioned uniform and transparent light yellow liquid in a microwave reactor (model: HKWB-10RB) to continue the reaction, and reset the microwave parameters. The parameters are set as follows: microwave power 1000W, temperature 90°C, microwave time 60 minutes, increase Microwave power and reaction temperature, open the action, the solut...

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Abstract

The invention provides a method for preparing high purity carbon quantum dots by using a microwave method, which is characterized in that the two-step segmentation microwave method is used, the method comprises the following steps: 1) placing a raw material solution in a microwave reactor, using microwave power at 400-800W, setting the temperature at 60-100 DEG C, preparing after 20-120 minutes of microwave action time; and 2) using microwave power at 800-1100W, setting the temperature at 80-300 DEG C, preparing the solution prepared in the step 1) to a solution containing carbon quantum dots after 20-120 minutes of microwave action time. According to the invention, a microwave reaction instrument substitutes a traditional microwave oven, microwave is carried out by two steps, first microwave is used for degrading a macro-molecule raw material, a low molecular raw material with moderate molecular weight and narrow molecular weight distribution can be obtained, uniformity of quantum dot particles can be finally ensured, and second microwave is used for preparing the carbon quantum dots with high yield and high purity.

Description

technical field [0001] The invention belongs to the preparation and purification technology of carbon quantum dots, in particular to a method for producing high-purity carbon quantum dots by a two-step segmental microwave method. Background technique [0002] Quantum dots (Quantum Dots, QDs) generally refer to semiconductor nanocrystals with a radius smaller than or close to the laser Bohr radius, and are nanometer-sized particles with unique optical and electrical properties. Traditional semiconductor quantum dots are composed of highly toxic metal elements, generally some transition metal sulfides or tellurides, such as cadmium sulfide, cadmium telluride, etc., which have biological toxicity and environmental hazards, and the synthesis conditions are harsh and the cost is high. , limiting its application in life sciences. With the development of carbon source materials such as carbon nanotubes, nanodiamonds, and graphene, carbon quantum dots have emerged as the times requ...

Claims

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Application Information

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IPC IPC(8): C01B31/02B82Y30/00C01B32/15
Inventor 张岐贾春满曹丽黄燕张春艳华明清
Owner 张岐
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