Aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability and preparation method thereof

Abstract

An aldehyde-ketone synthetic carbon dot with a high emulsification level and excellent wettability and a preparation method thereof belong to the technical field of two-dimensional interface materials. The present invention uses acetaldehyde and acetone as carbon sources, and controls the reaction time, aldehyde-ketone type, and aldehyde-ketone ratio to prepare a carbon dot material with a high emulsification level and excellent wettability, and applies the regulated prepared carbon dot material to the emulsification of toluene organic solvent to obtain an emulsion system with a high emulsification level. The present invention adopts a solvent thermal method, which does not require a reactor to heat and reduces energy consumption compared to the hydrothermal method. The carbon dots prepared by the present invention have extremely high adaptability in the emulsification system, and their unique surface chemical properties enable them to form a highly stable emulsion layer at the oil-water interface, effectively enhancing the emulsification effect. The aldehyde-ketone carbon dot material obtained by the present invention is uniform in size and has a high degree of dispersion, which can meet the emulsification requirements under different oil phase conditions, and has extremely low cost and a simple production process.

Description

Technical Field

[0001] The present invention belongs to the technical field of two-dimensional interface materials, and specifically relates to an aldehyde-ketone synthetic carbon dot with high emulsification level and excellent wettability and a preparation method thereof. Background Art

[0002] Emulsification technology is widely used in food, cosmetics, medicine, and materials engineering. However, existing emulsifiers have drawbacks such as high toxicity, environmental pollution, and insufficient stability. There is an urgent need to develop more environmentally friendly and efficient alternatives. Compared with traditional emulsifiers, carbon dot materials have the advantages of being non-toxic and biodegradable. At the same time, their surface properties and particle size distribution can be flexibly controlled by nitrogen doping ratio and preparation conditions. This makes carbon dot materials not only excellent in areas requiring high safety, such as food and cosmetics, but also exhibits high efficiency and long-lasting performance in industrial emulsification and material synthesis. In addition, the interfacial film formed can significantly reduce the occurrence of emulsion stratification, aggregation, and precipitation, thereby improving the long-term stability of the system.

[0003] Furthermore, the preparation of carbon dot materials offers significant advantages, including low cost, simple process, and environmental friendliness. Green raw material selection: Low-cost resources such as industrial waste and biomass can be used as raw materials for carbon dot preparation, reducing production costs. Efficient preparation: Low-energy hydrothermal and microwave methods simplify the preparation process, facilitating large-scale applications. Low environmental burden: Carbon dots exhibit excellent biodegradability, reducing the potential for emulsifier accumulation in the environment.

[0004] As a novel emulsifier, carbon dot materials not only address the safety and environmental concerns of existing emulsifiers but also offer a superior alternative. Their potential applications in green chemistry, the food industry, and the development of functional materials are broad, offering a new technological path and approach to sustainable development.

[0005] Currently reported methods for preparing carbon dot materials mainly fall into two categories: "top-down" and "bottom-up." The "top-down" method involves decomposing large carbon materials into nanoscale carbon dots through methods such as laser etching and chemical oxidation. The "bottom-up" method involves generating carbon dot materials from small organic precursors through methods such as hydrothermal, solvothermal, and pyrolysis. The "bottom-up" method produces carbon dot materials with higher purity. Patent CN119797336A discloses a method for preparing carbon dots using acetaldehyde as a carbon source and condensing it under the catalysis of NaOH. The resulting product exhibits a certain emulsification effect, with an emulsification rate of up to 80%. Summary of the Invention

[0006] The present invention aims to provide an aldehyde-ketone synthesized carbon dot with high emulsification level and excellent wettability and a preparation method thereof.

[0007] The present invention uses acetaldehyde and acetone as carbon sources, and prepares carbon dot materials with high emulsification level and excellent wettability by controlling the reaction time, aldehyde and ketone types, and aldehyde and ketone ratios, and applies the regulated prepared carbon dot materials to the emulsification of toluene organic solvent to obtain an emulsion system with high emulsification level. The present invention adopts a solvent thermal method, which does not require reactor heating and reduces energy consumption compared to the hydrothermal method. The carbon dots prepared by the present invention have extremely high adaptability in the emulsification system, and their unique surface chemical properties enable them to form a highly stable emulsion layer at the oil-water interface, effectively enhancing the emulsification effect. The aldehyde and ketone carbon dot materials obtained by the present invention are uniform in size and high in dispersion, and can meet the emulsification requirements under different oil phase conditions. They are also extremely low in cost and have a simple manufacturing process.

[0008] The present invention proposes a new preparation method. Compared with the existing patent CN119797336A, by adding acetone, the enolate anion formed by acetaldehyde under alkaline conditions can attack the carbonyl carbon of acetone, further undergoing aldol condensation. The final product also has better wettability, the emulsification rate is increased from 80% to 85%, and the stability time can reach more than several months, which is much longer than the situation of only about half a month in the patent.

[0009] The method for preparing aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability according to the present invention comprises the following steps:

[0010] (1) Prepare 5-10 M NaOH aqueous solution, stir for 20-30 minutes and then let it stand;

[0011] (2) Slowly add the NaOH aqueous solution prepared in step (1) dropwise to the 30-50% by mass acetaldehyde aqueous solution and acetone solution, complete the addition within 20-30 minutes and stir evenly;

[0012] (3) Stir the system obtained in step (2) for 2 to 5 hours at room temperature to obtain a dark brown paste solution;

[0013] (4) Add the hydrochloric acid solution dropwise to the dark brown paste solution obtained in step (3), adjust the pH of the solution to neutral, and then continue stirring for 4 to 12 hours until the system becomes a brown-yellow solution;

[0014] (5) Centrifuge the brown-yellow solution obtained in step (4) at 12,000 to 13,000 rpm for 3 to 5 minutes, remove the supernatant after centrifugation, and retain the precipitate;

[0015] (6) Add deionized water to the precipitate obtained in step (5), disperse it evenly by ultrasonication, remove the supernatant after centrifugation, and retain the precipitate; repeat the operation of "adding deionized water to the precipitate - ultrasonic dispersion - centrifugation - retaining the precipitate" 3 to 5 times to obtain a brown-yellow precipitate;

[0016] (7) The brown-yellow precipitate obtained in step (6) was freeze-dried with liquid nitrogen to obtain a yellow carbon dot material;

[0017] (8) Disperse 1-2 g of the yellow carbon dot material obtained in step (7) in 10-20 mL of methanol, add 1-2 g of potassium methoxide and 0.5-2 g of nitrogen source, and stir until there is no solid precipitation; the addition of potassium methoxide provides an alkaline environment and enhances nucleophilicity, thereby successfully introducing amino groups;

[0018] (9) heating and stirring the system obtained in step (8) at 70-90°C for 30-60 minutes;

[0019] (10) The system obtained in step (9) is centrifuged at a speed of 10,000 to 15,000 rpm for 2 to 5 minutes, the supernatant is removed, and the precipitate is retained and dried to obtain the aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability.

[0020] Furthermore, in step (2), the volume ratio of the NaOH aqueous solution to the acetaldehyde aqueous solution and the acetone solution is 1:1-3:3-5, the concentration of the hydrochloric acid solution in step (4) is 1-3 M, the freeze-drying conditions in step (7) are a temperature of -70 to -60°C and a vacuum degree of <10 Pa, the nitrogen source in step (8) is urea, thiourea, lysine, glycine and citrulline, and step (10) is vacuum drying at 60-80°C for 15-30 hours.

[0021] The aldehyde-ketone carbon dot material obtained in step (10) is added to deionized water for ultrasonic dispersion to obtain an aldehyde-ketone carbon dot material dispersion, and then the obtained aldehyde-ketone carbon dot material dispersion is mixed with toluene in a volume ratio of 1:1 and shaken, and quickly transferred to a colorimetric tube after shaking. After standing for 24 hours, the emulsification rate is measured to detect its amphiphilic emulsification performance; cottonseed oil and turpentine are used to prepare oil phases with different gradient HLB values (hydrophile-lipophile balance values), and then the aldehyde-ketone carbon dot material dispersion is mixed with the oil phases with different gradient HLB values, and an emulsion is prepared after ultrasonic shaking. After standing for 24 hours, the emulsification rate and HLB value are obtained by observing the emulsification results.

[0022] The technical solution of the present invention can quickly synthesize a large number of nano-scale aldehyde-ketone carbon dot materials with amphiphilic emulsification effects under mild reaction conditions. The obtained aldehyde-ketone carbon dot materials are uniform in size and highly dispersed, and can meet the emulsification requirements under different oil phase conditions. The cost is extremely low and the production process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 : Optical photograph of the aldehyde-ketone carbon dot material obtained in Example 1;

[0024] Figure 2: Transmission electron microscopy photograph of the aldehyde-ketone carbon dot material obtained in Example 1;

[0025] Figure 3 : XRD pattern of the aldehyde-ketone carbon dot material obtained in Example 1;

[0026] Figure 4 : Infrared image of the aldehyde-ketone carbon dot material obtained in Example 1;

[0027] Figure 5 : Optical photograph of the emulsification effect of the aldehyde-ketone carbon dot material obtained in Example 1;

[0028] Figure 6 : Leica electron microscope emulsification bubble image of the aldehyde and ketone carbon dot material obtained in Example 1;

[0029] Figure 7 : Water contact angle image of the aldehyde-ketone carbon dot material obtained in Example 1;

[0030] Figure 8 : Oil contact angle image of the aldehyde-ketone carbon dot material obtained in Example 1;

[0031] Figure 9 : Optical photograph of the oil phase with gradient HLB value after dispersion of aldehyde and ketone carbon dot material obtained in Example 1;

[0032] Figure 10 : Optical images of the emulsification effects of Examples 1 to 9;

[0033] Figure 11 : Leica electron microscope emulsification bubble images of Examples 1 to 9;

[0034] Table 1: Mass of cottonseed oil and turpentine required to prepare different HLB values

[0035] DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme, effect advantage of the embodiments of the present invention clearer, the embodiments will be described in more detail below, and it should be noted that the embodiments described below are not all embodiments, but only embodiments of the preferred invention conditions of the present invention. The reagents and instruments used in the embodiments can be purchased through normal commercial channels. Based on the embodiments of the present invention, those of ordinary skill in the art directly obtain the present embodiments without creative activities, and belong to the scope of protection of the present invention.

[0037] Example 1:

[0038] (1) Prepare 10 mL of 10 M NaOH aqueous solution, stir for 20 minutes and then let it stand;

[0039] (2) Slowly add the NaOH aqueous solution prepared in step (1) dropwise to 10 mL of 40% acetaldehyde aqueous solution and 30 mL of acetone solution, complete the addition within 20 minutes and stir evenly;

[0040] (3) Stirring the system obtained in step (2) for 3 h at room temperature to obtain a dark brown paste solution;

[0041] (4) Prepare 30 mL of 1 M hydrochloric acid solution; add the obtained hydrochloric acid solution dropwise to the dark brown paste solution obtained in step (3), adjust the solution to pH = 7.0, and then continue stirring for 8 hours to obtain a brown-yellow solution;

[0042] (5) Centrifuge the brown-yellow solution obtained in step (4) at 13,000 rpm for 5 minutes, remove the supernatant after centrifugation, and retain the precipitate;

[0043] (6) Add deionized water to the precipitate obtained in step (5), disperse it evenly by ultrasonication, remove the supernatant after centrifugation, and retain the precipitate; repeat the operation of "adding deionized water to the precipitate - ultrasonic dispersion - centrifugation - retaining the precipitate" 4 times to obtain a brown-yellow precipitate;

[0044] (7) The brown-yellow precipitate obtained in step (6) was freeze-dried using liquid nitrogen extraction (-65°C, vacuum degree <10Pa) to obtain 2.5 g of orange-yellow carbon dot material;

[0045] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of urea, and stir for 10 minutes until no solid precipitates;

[0046] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0047] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 3 minutes, the supernatant was removed, and the precipitate was retained and vacuum-dried at 80°C for 24 hours to obtain 0.8 g of aldehyde-ketone synthesized carbon dot material with high emulsification level and excellent wettability.

[0048] 20 mg of carbon dot material was added to 5 mL of deionized water and ultrasonicated for 10 minutes (frequency 40 kHz) to obtain a carbon dot material dispersion. The obtained carbon dot material dispersion was added to 5 mL of toluene to form a water-oil system. The system was then placed in a constant temperature shaker at 300 rpm for 1 hour. Finally, the system was transferred to a glass bottle, sealed, and allowed to stand for more than 24 hours. The height of the emulsion layer H was measured. 乳 And the total height H of the oil-water system 总 , according to the emulsification rate = (H 乳 / H 总) * 100%, the calculated emulsification rate was 85%. Leica electron microscope observation revealed an average diameter of 45 μm for the formed emulsified bubbles. The resulting carbon dot dispersion was added to 5 mL of an oil phase with a gradient of HLB values (HLB = 7-13). After mixing, the mixture was sonicated for 30 minutes (40 kHz) and allowed to stand for 24 hours. The system with the highest stability and emulsion layer height corresponded to an HLB value of 9-10.

[0049] Figure 1 This is a photo of the solid appearance of aldehyde-ketone carbon dot material, which is a yellow powder. Figure 2 This is a transmission electron microscope photo, from which it can be seen that the obtained aldehyde and ketone carbon dot materials have an average particle size of 2~4nm. Figure 3 This is the X-ray diffraction (XRD) spectrum of the aldehyde-ketone carbon dot material. It can be seen that the aldehyde-ketone carbon dot material has a broad peak at θ=20 degrees, corresponding to the highly graphitized structure of the aldehyde-ketone carbon dot material. Figure 4 This is the infrared (IR) spectrum of aldehyde and ketone carbon dot materials. It can be seen that the carbon dot materials have rich functional groups such as hydroxyl, carboxyl, alkyl, and epoxy groups. Figure 5 This is the emulsification effect diagram of aldehyde and ketone carbon dot materials. In the water / toluene system, the formed emulsion layer occupies the entire toluene phase and part of the water phase (toluene phase on the top and water phase on the bottom), forming a stable Pickering emulsion. Figure 6 This is a Leica electron microscope image of emulsified bubbles after adding aldehyde and ketone carbon dot materials to the water / toluene system. It can be seen that the emulsified bubbles formed are uniform in size, with an average diameter of 45μm. Figure 7 This is a photo of the water contact angle. It can be seen that the aldehyde and ketone carbon dots have a good hydrophilic effect. Figure 8 This is a photo of the oil (hexadecane) contact angle. It can be seen that the aldehyde-ketone carbon dots have a good lipophilic effect, indicating that the aldehyde-ketone carbon dot material has excellent wettability. Figure 9 This is an optical photograph of the carbon dot material dispersion in the gradient HLB value oil phase. The numbers in the figure represent the corresponding HLB values. It can be clearly seen that the emulsion layer heights of numbers 9 and 10 are the highest and the stabilization effect is the best, indicating that the HLB value range of aldehyde and ketone carbon dot materials is 9~10. Figure 10 These are optical photos of the emulsification effects of Examples 1 to 9. The emulsification rates of the examples can be calculated, with Example 1 having the best effect, with an emulsification rate of 85%, and a stable duration of up to several months. Figure 11 The emulsified bubble images of Examples 1 to 9 are taken under a Leica electron microscope. It can be observed that the emulsified bubbles formed by the emulsified system of Example 1 have an extremely narrow size distribution and the smallest average particle size of 45 μm. The emulsified layer formed in Example 7 is extremely unstable, and the emulsified bubbles demulsify rapidly. The emulsified bubbles formed in Example 9 are very dense but have a wide size distribution, and gradually demulsify and dissipate after 1 hour.

[0050] Example 2:

[0051] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0052] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of lysine, and stir for 10 minutes until no solid precipitates;

[0053] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0054] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 60°C for 24 hours to obtain 0.79 g of carbon dot material with a diameter of 6-15 nm, an emulsification rate of 40%, an average diameter of emulsified bubbles of 100 μm, and a stable emulsion layer without demulsification.

[0055] Example 3:

[0056] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0057] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of thiourea, and stir for 10 minutes until no solid precipitates;

[0058] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0059] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 60°C for 24 hours to obtain 0.56 g of carbon dot material with a diameter of 20-28 nm, an emulsification rate of 58%, an average diameter of emulsified bubbles of 80 μm, and a stable emulsion layer without demulsification.

[0060] Example 4:

[0061] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0062] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of glycine, and stir for 10 minutes until no solid precipitates;

[0063] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0064] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 60°C for 24 hours to obtain 0.61 g of carbon dot material with a diameter of 30-40 nm, an emulsification rate of 56%, an average diameter of emulsified bubbles of 80 μm, and a stable emulsion layer without demulsification.

[0065] Example 5:

[0066] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0067] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of citrulline, and stir for 10 minutes until no solid precipitates;

[0068] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0069] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 80°C for 24 hours to obtain 0.77 g of carbon dot material with a diameter of 12-15 nm, an emulsification rate of 45%, an average diameter of emulsified bubbles of 130 μm, and a stable emulsion layer without demulsification.

[0070] Example 6:

[0071] 10 mL of 40% acetaldehyde aqueous solution, 30 mL of acetone solution, and 20 mL of ammonia water (concentration is 27%) were mixed and reacted at 20°C for 3 hours. 30 mL of 1 M hydrochloric acid solution was added and the pH was adjusted to neutral. The remaining operations were the same as those in Example 1. No carbon dot material was produced after step (7).

[0072] Example 7:

[0073] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0074] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of aniline, and stir for 10 minutes until no solid precipitates;

[0075] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0076] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 80°C for 24 hours to obtain 1.1 g of carbon dot material with a diameter of 20-25 nm. The emulsification effect was very poor, the emulsion layer was unstable, and the emulsion broke quickly.

[0077] Example 8:

[0078] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0079] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of pyridine, and stir for 10 minutes until no solid precipitates;

[0080] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0081] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 60°C for 24 hours to obtain 0.78 g of carbon dot material with a diameter of 10-15 nm, an emulsification rate of 55%, an average diameter of emulsified bubbles of 70 μm, and demulsification after 1 hour.

[0082] Example 9:

[0083] Steps (1) to (7) were the same as in Example 1 to obtain 2.5 g of orange-yellow carbon dot material;

[0084] (8) Disperse 1 g of the orange-yellow carbon dot material obtained in step (7) in 10 mL of methanol, add 1 g of potassium methoxide and 1 g of arginine, and stir for 10 minutes until no solid precipitates;

[0085] (9) The system obtained in step (8) was heated and stirred at 80°C for 30 minutes;

[0086] (10) The system obtained in step (9) was centrifuged at 13,000 rpm for 5 minutes, the supernatant was removed, and the precipitate was retained and vacuum dried at 60°C for 24 hours to obtain 0.66 g of carbon dot material with a diameter of 15-20 nm, an emulsification rate of 44%, an emulsified bubble diameter of 90-105 μm, and demulsification after 1 hour.

[0087] In the examples, a mixed solution of acetaldehyde and acetone was added. An attempt to use acetone as the sole reagent was made, but acetone's own steric hindrance to condensation made the reaction difficult, and no carbon dots were formed under the same conditions. The carbon dot materials obtained in Examples 7, 8, and 9 exhibited some emulsification, but the emulsified bubbles quickly dissipated, indicating an unstable emulsification. This demulsification may be due to a weakening of Brownian motion, which in turn degrades the interfacial tension and prevents the emulsified bubbles from maintaining stability.

Claims

1. A method for preparing aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability, characterized by: The steps are as follows: (1) Prepare 5-10 M NaOH aqueous solution, stir for 20-30 minutes and then let it stand; (2) Slowly add the NaOH aqueous solution prepared in step (1) dropwise to the 30-50% by mass acetaldehyde aqueous solution and acetone solution, complete the addition within 20-30 minutes and stir evenly; the volume ratio of the NaOH aqueous solution to the acetaldehyde aqueous solution and acetone solution is 1:1-3:3-5; (3) Stir the system obtained in step (2) for 2 to 5 hours at room temperature to obtain a dark brown paste solution; (4) Add the hydrochloric acid solution dropwise to the dark brown paste solution obtained in step (3), adjust the pH of the solution to neutral, and then continue stirring for 4 to 12 hours until the system becomes a brown-yellow solution; (5) Centrifuge the brown-yellow solution obtained in step (4) at 12,000 to 13,000 rpm for 3 to 5 minutes, remove the supernatant after centrifugation, and retain the precipitate; (6) Add deionized water to the precipitate obtained in step (5), disperse it evenly by ultrasonication, remove the supernatant after centrifugation, and retain the precipitate; repeat the operation of "adding deionized water to the precipitate - ultrasonic dispersion - centrifugation - retaining the precipitate" 3 to 5 times to obtain a brown-yellow precipitate; (7) The brown-yellow precipitate obtained in step (6) was freeze-dried with liquid nitrogen to obtain a yellow carbon dot material; (8) Disperse 1-2 g of the yellow carbon dot material obtained in step (7) in 10-20 mL of methanol, add 1-2 g of potassium methoxide and 0.5-2 g of a nitrogen source, and stir until no solid precipitates; the nitrogen source is urea, thiourea, lysine, glycine, or citrulline; (9) heating and stirring the system obtained in step (8) at 70-90°C for 30-60 minutes; (10) The system obtained in step (9) is centrifuged at a speed of 10,000 to 15,000 rpm for 2 to 5 minutes, the supernatant is removed, and the precipitate is retained and dried to obtain the aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability.

2. The method for preparing aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability according to claim 1, characterized in that: The concentration of the hydrochloric acid solution in step (4) is 1~3 M.

3. The method for preparing aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability according to claim 1, characterized in that: The freeze-drying conditions in step (7) are a temperature of -70 to -60°C and a vacuum degree of <10Pa.

4. The method for preparing aldehyde-ketone synthesized carbon dots with high emulsification level and excellent wettability according to claim 1, characterized in that: In step (10), vacuum drying is performed at 60-80° C. for 15-30 hours.

5. An aldehyde-ketone synthesized carbon dot with high emulsification level and excellent wettability, characterized by: The invention is prepared by the preparation method according to any one of claims 1 to 4.

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