Hot bubble method for obtaining carbon quantum dots and carbon quantum dots obtained by the method

Abstract

The invention relates to the hot bubble method (100) used in the production of carbon quantum dots which are an organic -based type of quantum dots, frequently preferred to be used as bioimaging agents, in drug delivery systems, in solar batteries, in gene therapies, as therapeutic agents, as nanosensors and / or sensors or as LEDs in televisions; and to carbon quantum dots obtained by the method (100).

Description

[0001] HOT BUBBLE METHOD FOR OBTAINING CARBON QUANTUM DOTS AND CARBON QUANTUM DOTS OBTAINED BY THE METHOD

[0002] Technical Field

[0003] The invention relates to the hot bubble method used in the production of carbon quantum dots which are an organic -based type of quantum dots, frequently preferred to be used as bioimaging agents, in drug delivery systems, in solar batteries, in gene therapies, as therapeutic agents, as nanosensors and / or sensors or as LEDs in televisions; and to carbon quantum dots obtained by the method.

[0004] Background of the Invention

[0005] The known methods for carbon quantum dot synthesis are divided into two groups as the bottom-up approach or the top-down approach. In the synthesis of carbon quantum dots in their pure or processed forms, bottom-up approach methods include arc discharge and laser removal; bottom-up approach methods include electrochemical, thermal, hydrothermal, microwave-assisted, microwave-assisted hydrothermal and hot injection synthesis methods. In these synthesis methods, the formation of carbon quantum dots is generally determined by the color change, which can be considered as a relative feature, and the synthesis time is determined and terminated accordingly. Furthermore, the fact that the materials used in the synthesis methods are usually materials that may not be available in every laboratory, such as graphite electrodes, or that the synthesis is achieved as a result of being kept in an autoclave at very high temperatures or for very long periods of time, reduces the applicability of carbon quantum dot synthesis in every laboratory.

[0006] Among these methods, the hot injection method was carried out by using materials such as acetone, ethyl alcohol, sulfuric acid and diethyl ether, which are readily available and easily accessible in every laboratory; however, the formation of the carbon quantum dots was determined based on the color change, which can be considered relative. Again, among the mentioned methods, in another study, which demonstrates the obtaining of carbon quantum dots without relativity, the particles floating on the distilled water after the electric current was applied to graphite electrodes (1.2 M resistance) in distilled water were detected to be mostly carbon quantum dots. Although this method demonstrates the formation of carbon quantum dots in a non-relativistic way, it is assumed that the materials used in the synthesis are not as easily accessible as the materials used in the hot injection method.

[0007] Considering the above-mentioned methods of carbon quantum synthesis, most methods have the same disadvantages. Long synthesis times, high energy consumption during synthesis, working with materials that are not usually available in laboratory environments (except for the hot injection method), and the lack of indicators designating that the synthesis has been successfully carried out.

[0008] For this reason, there is a need for a new production method for carbon quantum dot synthesis that overcomes the mentioned shortcomings.

[0009] The Chinese patent document no. CN114410093, an application included in the state of the art, discloses a preparation method of carbon quantum dot polylactic acid oligomer. The invention subject to the said Chinese patent document belongs to the technical field of chemical materials and particularly relates to a preparation method and application of a carbon quantum dot polylactic acid oligomer. The carbon quantum dot polylactic acid oligomer comprises the following steps: Adding a carbon nanotube into a mixture of concentrated sulfuric acid and concentrated nitric acid, then stirring for reaction, the solution is filtered and dialyzed to obtain carbon quantum dot polylactic acid oligomer. A carbon quantum dot aqueous solution containing carboxyl and hydroxyl is obtained; uniformly mixing lactic acid with the carbon quantum dot aqueous solution prepared in the step 1, and then evaporating water in the mixed solution to obtain a carbon quantum dot lactic acid solution; adding a catalyst into the carbon quantum dot lactic acid solution, uniformly stirring, controlling the reaction temperature to be 140-150 °C, and introducing inert gas for protection in the whole reaction process to prepare a carbon quantum dot polylactic acid oligomerization crude product; and adding chloroform and an acetone solution into the carbon quantum dot polylactic acid oligomer crude product, and extracting the carbon quantum dot polylactic acid oligomer. The preparation method is simple and can be used as a toughening filler or a crosslinking agent of a polylactic acid material to improve the elongation at break of the polylactic acid material.

[0010] Summary of the Invention

[0011] An object of the present invention is to realize the hot bubble method used in the production of carbon quantum dots which are an organic -based type of quantum dots, frequently preferred to be used as bioimaging agents, in drug delivery systems, in solar batteries, in gene therapies, as therapeutic agents, as nanosensors and / or sensors or as LEDs in televisions; and to carbon quantum dots obtained by the method.

[0012] Another object of the present invention is to perform carbon quantum dot synthesis by the hot bubble method, a method that is highly applicable in the laboratory, can be synthesized with more than one organic solvent, can be carried out in a short time, and has an indicator designating that the synthesis has been successfully carried out.

[0013] Detailed Description of the Invention

[0014] “Hot Bubble Method for Obtaining Carbon Quantum Dots and Carbon Quantum Dots Obtained by The Method” realized to fulfd the objectives of the present invention is shown in the figure attached, in which: Figure 1 is a flowchart of the inventive method.

[0015] The components illustrated in the figure are individually numbered, where the numbers refer to the following:

[0016] 100. Method

[0017] The inventive hot bubble method (100) for synthesizing carbon quantum dots, which is highly applicable in the laboratory, can be synthesized with more than one organic solvent, can be carried out in a short time and has an indicator designating that the synthesis has been successfully carried out comprises the steps of mixing sulfuric acid and acetone in a single or two neck silicoborate beaker (101); connecting the mixture to the reflux condenser (102); forming the carbon quantum dots and the water bubble, an indicator, by the dehydration reaction taking place between sulfuric acid and acetone (103); and carrying out neutralization and purification processes (104).

[0018] At the step of mixing sulfuric acid and acetone in a single or two neck silicoborate beaker (101) of the inventive method (100), pure acetone with sulfuric acid 96-98% in a 2: 1 ratio is put into a single or two neck volumetric flask that is placed in a beaker with silicone oil on its base and the carbon quantum dot synthesis is initiated by mixing them by heating from laboratory temperature to 150- 165 °C at 400-500 rpm with a magnetic stirrer with hotplate. During the synthesis, the temperature of the heated silicone oil is measured with a food thermometer.

[0019] At the step of connecting the mixture to the reflux condenser (102) of the inventive method (100), the cold water recirculation system connected to the reflux condenser in order to prevent the mixture from heating up too fast during the synthesis is added to the experimental setup comprising the beaker and the volumetric flask, and this system operates by connecting the power supply to a small motor and energizing it with 9V. The connection between the reflux condenser and the single or two neck volumetric flask is established by parafilm coating. The beaker containing the silicone oil is covered with glass wool so as to prevent the loss of heat transmitted by the magnetic stirrer with hotplate, and nitrogen gas (N2) contained in the fume cupboard is introduced into the reflux condenser fitted with a plastic cork on the end in order for the synthesis to be carried out in an inert environment.

[0020] At the step of forming the carbon quantum dots and the water bubble, an indicator, by the dehydration reaction taking place between sulfuric acid and acetone (103) of the inventive method (100), with the temperature of the beaker containing silicone oil reaching between 150-165°C within 3.5-4 hours, the dehydration reaction between sulfuric acid and acetone takes place in this temperature range. The dehydration reaction taking place between sulfuric acid and acetone is shown by equation (1). Mesitylene molecules and water, which form carbon quantum dots by coming together, are formed as a result of the dehydration reaction. The formed water molecules start to appear on the edge and surface of the mixture as water bubbles since the synthesis takes place in an inert and hot environment. Once the bubbles completely cover the surface of the mixture, it is waited for 30-60 seconds and then the mixture is removed from the hot environment and allowed to cool at room temperature.

[0021] At the step of carrying out neutralization and purification processes (104) of the inventive method (100), a 50-80 mL solution of 5 M sodium hydroxide (NaOH) is added to the mixture in order to neutralize the mixture once the obtained mixture reaches room temperature. The mixture is mixed in such a way that the ratio of deionized water is 1: 1 and centrifuged at 5000-10000 rpm for 15-20 minutes in order to purify the neutral mixture. The supernatant is separated from the precipitate (pellet) after centrifugation and centrifuged again at 5000-10000 rpm for 15-20 minutes after being dissolved in deionized water in certain volumes based on the pellet amount. The supernatant is separated from the precipitate (pellet) after the 2nd centrifugation and centrifuged again at 5000-10000 rpm for 15-20 minutes after being dissolved in deionized water in certain volumes based on the pellet amount. The precipitate (pellet) separated from the supernatant after the last centrifugation is dissolved in a 500 pl-1 mL of deionized water based on the precipitate amount, and the mixture purified by centrifugation is passed through a dialysis membrane (MWCO: 1 kDa) for 1-3 days in the beaker in which the deionized water mixed with a magnetic stirrer is contained. The deionized water in which the water and membrane are contained is changed every 3-6 hours.

[0022] Carbon quantum dot synthesis by the hot bubble method (100) is a method that has high applicability in the laboratory, can be synthesized with more than one organic solvent, can be carried out in a short time, and has an indicator (bubble covering the surface of the mixture) designating that the synthesis has been successfully carried out.

[0023] Quantum dots synthesized with the hot bubble carbon quantum dot synthesis method (100) are used as bioimaging agents, in the detection of certain heavy metal ions, in the production of light emitting diodes (LEDs), as in-vivo imaging agents, for integration into dialysis membranes, in drug delivery systems and gene therapies.

[0024] Within these basic concepts; it is possible to develop various embodiments of the inventive “Hot Bubble Method (100) for Obtaining Carbon Quantum Dots and Carbon Quantum Dots Obtained by The Method”; the invention cannot be limited to examples disclosed herein and it is essentially according to claims.

Claims

CLAIMS1. The hot bubble method (100) for synthesizing carbon quantum dots, which is highly applicable in the laboratory, can be synthesized with more than one organic solvent, can be carried out in a short time and has an indicator designating that the synthesis has been successfully carried out; characterized in that it comprises the steps of; mixing sulfuric acid and acetone in a single or two neck silicoborate beaker (101); connecting the mixture to the reflux condenser (102); forming the carbon quantum dots and the water bubble, an indicator, by the dehydration reaction taking place between sulfuric acid and acetone (103); and carrying out neutralization and purification processes (104).

2. A method (100) according to Claim 1; characterized in that at step of mixing sulfuric acid and acetone in a single or two neck silicoborate beaker (101), pure acetone with sulfuric acid 96-98% in a 2:1 ratio is put into a single or two neck volumetric flask that is placed in a beaker with silicone oil on its base and the carbon quantum dot synthesis is initiated by mixing them by heating from laboratory temperature to 150-165°C at 400-500 rpm with a magnetic stirrer with hotplate.

3. A method (100) according to Claim 1; characterized in that at step of connecting the mixture to the reflux condenser (102), the cold water recirculation system connected to the reflux condenser in order to prevent the mixture from heating up too fast during the synthesis is added to the experimental setup comprising the beaker and the volumetric flask, and this system operates by connecting the power supply to a small motor and energizing it with 9V.

4. A method (100) according to Claim 3 ; characterized in that the connection between the reflux condenser and the single or two neck volumetric flask is established by parafilm coating.

5. A method (100) according to Claim 3 or 4; characterized in that the beaker containing the silicone oil is covered with glass wool to prevent the loss of heat transmitted by the magnetic stirrer with hotplate, and nitrogen gas (N2) contained in the fume cupboard is introduced into the reflux condenser fitted with a plastic cork on the end in order for the synthesis to be carried out in an inert environment.

6. A method (100) according to Claim 1; characterized in that at step of forming the carbon quantum dots and the water bubble, an indicator, by the dehydration reaction taking place between sulfuric acid and acetone (103), with the temperature of the beaker containing silicone oil reaching between 150-165°C within 3.5-4 hours, the dehydration reaction between sulfuric acid and acetone takes place in this temperature range.

7. A method (100) according to Claim 6; characterized in that the mesitylene molecules and water, which form carbon quantum dots by coming together, are formed as a result of the dehydration reaction, and the formed water molecules start to appear on the edge and surface of the mixture as water bubbles since the synthesis takes place in an inert and hot environment.

8. A method (100) according to Claim 6 or 7; characterized in that once the bubbles completely cover the surface of the mixture, it is waited for 30-60 seconds and then the mixture is removed from the hot environment and allowed to cool at room temperature.

9. A method (100) according to Claim 1; characterized in that at step of carrying out neutralization and purification processes (104), a 50-80 mLsolution of 5 M sodium hydroxide (NaOH) is added to the mixture in order to neutralize the mixture once the obtained mixture reaches room temperature.

10. A method (100) according to Claim 9; characterized in that the mixture is mixed in such a way that the ratio of deionized water is 1: 1 and centrifuged at 5000-10000 rpm for 15-20 minutes in order to purify the neutral mixture.

11. A method (100) according to Claim 9 or 10; characterized in that the supernatant is separated from the precipitate (pellet) after centrifugation and centrifuged again at 5000-10000 rpm for 15-20 minutes after being dissolved in deionized water in certain volumes based on the pellet amount.

12. A method (100) according to any one of the claims 9 to 11; characterized in that the supernatant is separated from the precipitate (pellet) after the 2nd centrifugation and centrifuged again at 5000-10000 rpm for 15-20 minutes after being dissolved in deionized water in certain volumes based on the pellet amount.

13. A method (100) according to any one of the claims 9 to 12; characterized in that the precipitate (pellet) separated from the supernatant after the last centrifugation is dissolved in a 500 pl-1 mL of deionized water based on the precipitate amount, and the mixture purified by centrifugation is passed through a dialysis membrane for 1-3 days in the beaker in which the deionized water mixed with a magnetic stirrer is contained.

14. A method (100) according to any one of the claims 9 to 13; characterized in that the deionized water in which the water and membrane are contained is changed every 3-6 hours.

15. Carbon quantum dots synthesized by the steps of method (100) above, which are used as bioimaging agents, in the detection of certain heavy metal ions, in the production of light emitting diodes (LED), as in-vivo imaging agents, for integration into dialysis membranes, in drug delivery systems and gene therapies.

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