A lubricant with high carbon dot dispersion stability and preparation method thereof

Abstract

The present invention discloses a lubricant with high carbon dot dispersion stability and a preparation method thereof, which belongs to the field of lubricant preparation. Carbon dots are added to an organic solvent additive, and the carbon dots are uniformly dispersed in the organic solvent additive by ultrasound, and then the organic solvent additive containing the carbon dots is dissolved in the lubricant to prepare the lubricant with high carbon dot dispersion stability. The present invention provides a preparation method of a lubricant with high carbon dot dispersion stability, which effectively improves the long-term dispersion stability of carbon dots in the lubricant by using a dispersion additive, and the dispersion effect is obvious and long-term stable.

Description

Technical Field

[0001] The invention belongs to the field of lubricant preparation, and in particular relates to a lubricant with high carbon dot dispersion stability and a preparation method thereof. Background Art

[0002] Suitable lubricants can effectively reduce friction and wear, reduce component failures, and extend the service life of mechanical equipment. This is very important for improving equipment operating efficiency and reducing maintenance costs. As the manufacturing industry develops towards high precision and high efficiency, higher requirements are placed on lubrication technology. Lubricant research helps to meet the needs of advanced manufacturing and promote technological progress. CDS (carbon dots) as a new type of lubricant additive has a wide range of advantages. Surface functionalized carbon dots can form a protective friction film on the friction layer, reduce surface wear, and improve the reliability of mechanical parts. Carbon dots have high thermal stability in high temperature environments and can effectively prevent lubricants from failing prematurely. In addition, the preparation process of carbon dots is relatively simple, the raw materials are widely available, and the cost is low. However, the dispersion stability of carbon dots is poor, especially in oily lubricants, carbon dots are easy to agglomerate, and it is difficult to disperse evenly in the lubricant, which affects the performance. Summary of the invention

[0003] The purpose of the present invention is to provide a lubricant with high carbon dot dispersion stability and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art.

[0004] One of the technical solutions provided by the present invention:

[0005] A method for preparing a lubricant with high carbon dot dispersion stability comprises adding carbon dots into an organic solvent auxiliary agent, uniformly dispersing the carbon dots in the organic solvent auxiliary agent through ultrasound, and then dissolving the organic solvent auxiliary agent containing the carbon dots into the lubricant to prepare the lubricant with high carbon dot dispersion stability.

[0006] Preferably, when the lubricant is a lipid lubricating oil, the organic solvent additive is acetone.

[0007] Preferably, the volume ratio of the acetone to the lipid lubricating oil is (5-10):100, and more preferably, the volume ratio of the acetone to the lipid lubricating oil is 10:100.

[0008] More preferably, the mass of the carbon dots accounts for 0.1-0.5% of the mass of the lipid lubricant.

[0009] Preferably, when the lubricant is a base oil, the organic solvent additive is oleylamine.

[0010] Preferably, the volume ratio of the oleylamine to the base oil is (5-15):100, and more preferably, the volume ratio of the oleylamine to the base oil is 15:100.

[0011] More preferably, the mass of the carbon dots accounts for 0.1-0.5% of the mass of the base oil.

[0012] The technical principle of the present invention is: first, carbon dots are added to an organic solvent additive to make them uniformly dispersed in the organic solvent additive, and then the organic solvent additive containing carbon dots is dissolved in a lubricant. Since the organic solvent additive and the lubricant are similarly compatible, the carbon dots dispersed in the organic solvent additive are also uniformly dispersed in the lubricant along with the organic solvent additive. By further adjusting the volume ratio of the organic solvent additive and the carbon dots and the amount of carbon dots added, the long-term dispersion stability of the carbon dots in the lubricant is improved.

[0013] The second technical solution provided by the present invention is:

[0014] A lubricant with high carbon dot dispersion stability is prepared by the preparation method.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects:

[0016] The present invention provides a method for preparing a lubricant with high carbon dot dispersion stability. The long-term dispersion stability of carbon dots in the lubricant is effectively improved by utilizing a dispersing aid, and the dispersion effect is obvious and long-term stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 This is a transmission electron microscope image of the carbon dots prepared in the present invention;

[0019] Figure 2 The dispersion state photos of the lubricants obtained in Examples 1-3 and Comparative Example 1 after standing for 15 days are Z-0-S, Z-5-S, Z-8-S, and Z-10-S from left to right;

[0020] Figure 3 The particle size distribution diagram of carbon dots in the lubricants obtained in Examples 1-3 and Comparative Example 1 in lipid lubricating oil;

[0021] Figure 4 This is a photo of the dispersion state of the lubricant obtained in Comparative Example 2 after being left to stand for 2 days;

[0022] Figure 5 This is a photo of the dispersion state of the lubricant obtained in Comparative Example 3 after standing for 15 days;

[0023] Figure 6 This is a photo of the dispersion state of the lubricant obtained in Comparative Example 4 after standing for 15 days;

[0024] Figure 7 This is a photo of the dispersion state of the lubricant obtained in Comparative Example 5 after standing for 5 days;

[0025] Figure 8 The dispersion state pictures of the lubricants obtained in Examples 4-7 and Comparative Example 6 after standing for 15 days are J-0-S, J-5-S, J-8-S, J-10-S, and J-15-S from left to right;

[0026] Fig. 9 The particle size distribution diagram of carbon dots in the base oil in the lubricants obtained in Examples 6-7 and Comparative Example 6;

[0027] Fig.10 This is a photo of the dispersion state of the lubricant obtained in Comparative Example 7 after being left to stand for 2 days;

[0028] Fig.11 This is a photograph of the dispersion state of the lubricant obtained in Comparative Example 8 after being left to stand for 5 days. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0031] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0032] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present application description and examples are exemplary only.

[0033] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0034] In some embodiments of the present invention, carbon dots are added to acetone, ultrasonically treated, and then poured into a lipid lubricant. After ultrasonic treatment, the mixture is stirred to prepare a lubricant with high carbon dot dispersion stability. The volume ratio of the acetone to the lipid lubricant is (5-10):100, and the mass of the carbon dots accounts for 0.1-0.5% of the mass of the lipid lubricant.

[0035] In other embodiments of the present invention, carbon dots are added to oleylamine, ultrasonically treated, and then poured into base oil. After ultrasonic treatment, the mixture is stirred to prepare a lubricant with high carbon dot dispersion stability. The volume ratio of the oleylamine to the base oil is (5-15):100, and the mass of the carbon dots accounts for 0.1-0.5% of the mass of the base oil.

[0036] The lipid lubricating oil required in the embodiments of the present invention is sourced from Shenzhen Yuepengfu Chemical Co., Ltd., the base oil is sourced from Shenzhen Yuepengfu Chemical Co., Ltd., the acetone is sourced from Yonghua Chemical Technology Co., Ltd., and the oleylamine is sourced from Aladdin Biochemical Technology Co., Ltd.

[0037] The method for preparing carbon dots in the embodiment of the present invention is as follows:

[0038] Pour 20 mL of acetaldehyde solution into a beaker, and slowly add 2 g of urea and 6 g of sodium hydroxide during stirring. After adding the reaction reagents, stir the solution for 2 h. After the reaction is completed, pour in 50 mL of distilled water, continue ultrasonic treatment, add hydrochloric acid to neutralize pH = 7, and stir until uniformly dispersed. Wash the resulting flocculated sample twice with deionized water, and freeze-dry the final product for 48 h to prepare about 4.12 g of carbon dots. Figure 1 The transmission electron microscope image of the carbon dots prepared in the present invention is shown in FIG. Figure 1 It can be seen that the carbon dots prepared by this method have good particle size uniformity and an average particle size of 3.2 nm.

[0039] Example 1

[0040] 10 mg of carbon dots were added to 0.45 mL of acetone, ultrasonically treated for 10 min, and then poured into a beaker containing 10 g (9 mL) of ester lubricating oil so that the volume concentration of acetone in the ester lubricating oil was 5%. After ultrasonic treatment for 30 min, stirring was continued for another 30 min. The lubricant with high carbon dot dispersion stability was recorded as Z-5-S.

[0041] Example 2

[0042] 10 mg of carbon dots were added to 0.72 mL of acetone and ultrasonically treated for 10 min. The mixture was then poured into a beaker containing 10 g (9 mL) of ester lubricating oil so that the volume concentration of acetone in the ester lubricating oil was 8%. After ultrasonic treatment for 30 min, the mixture was stirred for another 30 min. The lubricant with high carbon dot dispersion stability was recorded as Z-8-S.

[0043] Example 3

[0044] 10 mg of carbon dots were added to 0.9 mL of acetone and ultrasonically treated for 10 min. The mixture was then poured into a beaker containing 10 g (9 mL) of ester lubricant oil so that the volume concentration of acetone in the ester lubricant oil was 10%. After ultrasonic treatment for 30 min, the mixture was stirred for another 30 min. The resulting lubricant with high carbon dot dispersion stability was recorded as Z-10-S.

[0045] Comparative Example 1

[0046] 10 mg of carbon dots were directly poured into a beaker containing 10 g (9 mL) of lipid lubricating oil, ultrasonically treated for 30 min, and then stirred for another 30 min. The resulting sample was recorded as Z-0-S.

[0047] Figure 2 The dispersion state of the lubricants obtained in Examples 1-3 and Comparative Example 1 after standing for 15 days is shown in the following pictures, from left to right: Z-0-S, Z-5-S, Z-8-S, Z-10-S, Figure 2 It can be seen that after 15 days of storage, Z-0-S has obvious precipitation in the lower layer, which proves that the carbon dots have a certain degree of agglomeration, indicating that the stability of Z-0-S without the addition of organic solvent additives is poor; while Z-5-S and Z-8-S have almost no sedimentation after 15 days of storage, indicating that the acetone additive can effectively improve the dispersion stability of carbon dots in ester lubricants, and Z-10-S lubricant is still clear and transparent after 15 days of storage, showing excellent uniformity, indicating that the stability of Z-5-S, Z-8-S, and Z-10-S can meet the requirements, especially Z-10-S has the best dispersion stability. Considering that too much dispersant will reduce the viscosity of ester lubricants, thereby affecting their friction properties, the dispersant should not be too much, just meet the dispersion requirements.

[0048] Figure 3The particle size distribution diagram of carbon dots in the lubricants obtained in Examples 1-3 and Comparative Example 1 in lipid lubricating oil shows that acetone has good compatibility with lipid lubricating oil and can promote the stable dispersion of carbon dots in base oil as a dispersing aid. Figure 3 It can be seen that with the increase of acetone content, the particle size of carbon dots in lipid oil decreases significantly, indicating that the acetone additive is beneficial to hinder the agglomeration of carbon dots in lipid oil and promote its dispersion. When the volume of acetone is 10% of the lipid oil, the average particle size of the carbon dots is about 116.8nm, and there is almost no sedimentation after standing for 15 days.

[0049] Comparative Example 2

[0050] 10 mg of carbon dots were added to a beaker containing 10 g (9 mL) of lipid lubricant, ultrasonically treated for 30 min, stirred for 30 min, then added to 0.9 mL of acetone and ultrasonically treated for 10 min. The sample obtained in Comparative Example 2 was left to stand for 2 days, and the dispersion of carbon dots in the lubricant was shown in Table 1. Figure 4 ,Depend on Figure 4 It can be seen that in this comparative example, since the carbon dots were first added to the lipid lubricating oil and then acetone was added, slight sedimentation occurred after standing for 2 days.

[0051] Comparative Example 3

[0052] The same as Example 1, except that acetone was replaced by N,N-dimethylformamide. The sample prepared in this comparative example was left to stand for 15 days, and the dispersion of carbon dots in the lubricant was observed. Figure 5 ,Depend on Figure 5 It can be seen that when acetone is replaced by N,N-dimethylformamide, the solution is no longer clear and transparent after standing for 15 days.

[0053] Comparative Example 4

[0054] The same as Example 1, except that acetone was replaced by ethyl acetate. The sample prepared in this comparative example was left to stand for 15 days, and the dispersion of carbon dots in the lubricant was observed. Figure 6 ,Depend on Figure 6 It can be seen that when acetone was replaced with ethyl acetate, precipitation appeared at the bottom after standing for 15 days.

[0055] Comparative Example 5

[0056] 100 mg of carbon dots were added to 9 mL of acetone and ultrasonically treated for 10 min. Then, the mixture was poured into a beaker containing 10 g (9 mL) of lipid lubricating oil and ultrasonically treated for 30 min. The mixture was stirred for another 30 min. Figure 7 This is a picture of the comparison sample after it was left to stand for 5 days. Figure 7 It can be seen that due to excessive addition of carbon dots, a small amount of precipitation will appear at the bottom.

[0057] Example 4

[0058] 7 mg of carbon dots were added to 0.4 mL of oleylamine, ultrasonically treated for 10 min, and then poured into a beaker containing 7 g (8 mL) of base oil so that the volume concentration of oleylamine in the base oil was 5%. After ultrasonic treatment for 3 min, stirring was continued for 30 minutes. The resulting lubricant with high carbon dot dispersion stability was recorded as J-5-S.

[0059] Example 5

[0060] 7 mg of carbon dots were added to 0.64 mL of oleylamine, ultrasonically treated for 10 min, and then poured into a beaker containing 7 g (8 mL) of base oil so that the volume concentration of oleylamine in the base oil was 8%. After ultrasonic treatment for 3 min, stirring was continued for 30 minutes. The resulting lubricant with high carbon dot dispersion stability was recorded as J-8-S.

[0061] Example 6

[0062] 7 mg of carbon dots were added to 0.8 mL of oleylamine, ultrasonically treated for 10 min, and then poured into a beaker containing 7 g (8 mL) of base oil so that the volume concentration of oleylamine in the base oil was 10%. After ultrasonic treatment for 3 min, stirring was continued for 30 minutes. The resulting lubricant with high carbon dot dispersion stability was recorded as J-10-S.

[0063] Example 7

[0064] 7 mg of carbon dots were added to 1.2 mL of oleylamine, ultrasonically treated for 10 min, and then poured into a beaker containing 7 g (8 mL) of base oil so that the volume concentration of oleylamine in the base oil was 15%. After ultrasonic treatment for 3 min, stirring was continued for 30 minutes. The resulting lubricant with high carbon dot dispersion stability was recorded as J-15-S.

[0065] Comparative Example 6

[0066] 7 mg of carbon dots were directly poured into a beaker containing 7 g (8 mL) of base oil, ultrasonically treated for 30 min, and then stirred for another 30 min. The resulting lubricant was recorded as J-0-S.

[0067] Figure 8 The dispersion state pictures of the lubricants obtained in Examples 4-7 and Comparative Example 6 after being left to stand for 15 days are J-0-S, J-5-S, J-8-S, J-10-S, and J-15-S from left to right. Figure 8 It can be seen that the carbon dots in J-0-S are completely separated from the base oil, indicating that the stability of the carbon dots in the base oil is extremely poor when there is no organic co-solvent; while a small amount of precipitates are precipitated in J-5-S and J-8-S, and almost no precipitates are precipitated in J-10-S and J-15-S, especially J-15-S, which shows excellent dispersibility and stability, indicating that J-15-S has the best stability.

[0068] Fig. 9 The particle size distribution diagram of carbon dots in the base oil in the lubricants obtained in Examples 6-7 and Comparative Example 6 shows that oleylamine has good compatibility with the base oil and can promote the stable dispersion of carbon dots in the base oil as a dispersing aid. Fig. 9 It can be seen that with the increase of oleylamine content, the particle size of carbon dots in lipid oil decreases significantly. When the volume of oleylamine is 15% of the base oil, the average particle size of carbon dots is about 80.6nm, and there is almost no sedimentation after standing for 15 days.

[0069] Comparative Example 7

[0070] 7 mg of carbon dots were added to a beaker containing 7 g (8 mL) of base oil, ultrasonically treated for 30 min, stirred for another 30 min, then added to 1.2 mL of oleylamine and ultrasonically treated for 10 min. The comparative sample was left to stand for 2 days. Fig.10 ,from Fig.10 It can be seen that obvious sedimentation of carbon dots occurs in the lubricant to which oleylamine is added later.

[0071] Comparative Example 8

[0072] 50 mg of carbon dots were added to 1.2 mL of oleylamine and ultrasonically treated for 10 min. Then, the mixture was poured into a beaker containing 7 g (8 mL) of base oil so that the volume concentration of oleylamine in the base oil was 15%. After ultrasonic treatment for 3 min, the mixture was stirred for another 30 min. Fig.11 This is a picture of the comparative sample left to stand for 5 days. Fig.11 It can be seen that too much addition is not conducive to the distribution of carbon dots.

[0073] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A lubricant with high carbon dot dispersion stability, characterized in that: The preparation method of the lubricant with high carbon dot dispersion stability comprises: adding carbon dots to an organic solvent auxiliary agent, uniformly dispersing the carbon dots in the organic solvent auxiliary agent by ultrasound, and then dissolving the organic solvent auxiliary agent containing the carbon dots in the lubricant to prepare the lubricant with high carbon dot dispersion stability; The lubricant is an ester lubricating oil, and the organic solvent additive is acetone; The volume ratio of the acetone to the ester lubricating oil is (5-10):100; The mass of carbon dots accounts for 0.1-0.5% of the mass of the ester lubricant; the method for preparing carbon dots is: pouring 20mL of acetaldehyde solution into a beaker, and slowly adding 2g of urea and 6g of sodium hydroxide during stirring; after adding the reaction reagent, stirring the solution for 2h, after the reaction is completed, pouring 50mL of distilled water, continuing ultrasonic treatment, and adding hydrochloric acid to neutralize pH=7, and stirring until uniformly dispersed, washing the obtained flocculated sample twice with deionized water, and freeze-drying the final product for 48h to prepare carbon dots.

2. The lubricant with high carbon dot dispersion stability according to claim 1, characterized in that The volume ratio of the acetone to the ester lubricating oil is 10:100.

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