CN108907182A - A kind of water solubility Cu@SiO2Nanoparticle and its preparation method and application - Google Patents

Abstract

The invention belongs to the field of water-based lubricating additives, and specifically relates to a water-soluble Cu@ _SiO2 nanoparticle, which is mainly prepared from the following raw materials in parts by weight: 0.1-2 parts of surface-modified oil-soluble nano-copper (DDP‑Cu), ring 60-90 parts of hexane, 5-15 parts of Igepal CO-520, 0.5-7 parts of TEOS, 0.1-3 parts of ammonia water, and 0.2-5 parts of distilled water. The present invention also provides a method for preparing the above-mentioned water-soluble Cu@SiO ₂ nanoparticles. The prepared Cu@SiO ₂ nanoparticles exhibit excellent dispersion stability and anti-oxidation stability, and when used as a water-based lubricating additive, the performance It has good anti-friction and anti-wear properties and has excellent application prospects.

Description

A kind of water-soluble Cu@SiO2 nanoparticles and its preparation method and application

technical field

The invention belongs to the field of water-based lubricating additives, and in particular relates to a preparation method of water-soluble Cu@ _SiO2 nanoparticles and its application as a water-based lubricating additive.

Background technique

Copper nanoparticles are widely used in the field of tribology due to their low shear force, low melting point and good self-healing effect, showing excellent anti-friction and anti-wear properties. Copper nanoparticles themselves are in a chemically unstable state. When synthesizing smaller copper nanoparticles due to high surface energy, agglomeration and oxidation will occur. In order to overcome this shortcoming, many researchers use surface modification technology to modify the surface of copper nanoparticles in order to effectively improve the dispersion stability and oxidation stability of copper nanoparticles in lubricants. The study found that in the synthesis of high-quality copper nanoparticles, the synthesis of oil-soluble copper nanoparticles has advantages over the synthesis of water-soluble copper nanoparticles.

In the early stage, we have obtained oil-soluble surface-modified oil-soluble nano-copper with excellent tribological properties (hereinafter referred to as DDP-Cu nanoparticles, ZL200910065056.4, a preparation method for surface-modified oil-soluble nano-copper), however, because the surface The modifier DDP is hydrophobic, so DDP-Cu nanoparticles cannot be directly used in water-based lubrication systems. Silica itself has good tribological properties and can inhibit the oxidation and agglomeration of copper nanoparticles, and the presence of a large number of Si-OH (polar groups) on the surface of the silica shell helps to significantly increase the Dispersion stability in water-based lubricants.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a water-soluble Cu@SiO ₂ nanoparticle, which uses the silica coating method to successfully transfer the oil-soluble DDP-Cu nanoparticle into the water phase to prepare the morphology Good, uniform size water-soluble Cu@ _SiO2 nanoparticles, which have good dispersion stability and anti-oxidation stability in distilled water. The water-soluble Cu@SiO ₂ nanoparticles of the present invention are used as water-based lubricating additives, can effectively improve the tribological properties of distilled water, and have broad application prospects.

The present invention also provides a preparation method of the above-mentioned water-soluble Cu@SiO ₂ nanoparticles and its application as a water-based lubricating additive.

To achieve the above object, the present invention adopts the following technical solutions:

In the present invention, the oil-soluble DDP-Cu nanoparticles are coated with a silica shell, and the oil-soluble DDP-Cu nanoparticles are successfully transferred to the water phase, and a water-soluble Cu@SiO ₂ nanoparticle is prepared; the The water-soluble Cu@ _SiO2 nanoparticles are mainly made of the following raw materials in parts by weight:

Surface modification oil-soluble nano-copper 0.1-2 parts,

Cyclohexane 60～90 parts,

Igepal CO-520 5~15 parts,

TEOS (tetraethyl silicate) 0.5 to 7 parts,

Ammonia 0.1~3 parts,

0.2 to 5 parts of distilled water.

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles, which specifically includes the following steps:

1) Take each raw material in proportion, and mix the surface-modified oil-soluble nano-copper and cyclohexane evenly to obtain a mixed solution a;

2) Add surfactant Igepal CO-520 to the mixed solution a obtained in step 1), stir and react to obtain mixed solution b;

3) Add TEOS to the mixed solution b obtained in step 2), stir and react to obtain mixed solution c;

4) Add ammonia water and distilled water to the mixed solution c obtained in step 3), stir and react for 12-40 h; after the reaction, centrifuge, wash and dry.

Specifically, in step 1), uniform mixing is carried out by mixing and stirring at room temperature, and the mixing and stirring time is 5-30 min.

Specifically, in steps 2) and 3), the stirring reaction is carried out at room temperature, and the stirring reaction time is 5-30 min.

In the present invention, the raw material surface-modified oil-soluble nano-copper (DDP-Cu nanoparticles) can be prepared by referring to the patent "ZL200910065056.4, a preparation method of surface-modified oil-soluble nano-copper". Raw material surfactants Igepal CO-520 and TEOS can be purchased from common commercially available products. The raw ammonia water is concentrated ammonia water with a concentration of 25-28%, and ordinary commercially available products can be purchased.

The present invention also provides the application of the above-mentioned water-soluble Cu@SiO ₂ nanoparticles as a water-based lubricating additive.

In the present invention, the oil-soluble DDP-Cu nanoparticles are transferred to the water phase by using the coating of the silica shell layer by the reverse-phase microemulsion method, and water-soluble Cu@ _SiO2 nanoparticles with uniform size and good shape are obtained. ;Using it as a water-based lubricating additive has good dispersion stability and anti-oxidation stability, and can significantly improve the anti-friction and anti-wear properties of distilled water, and has broad application prospects. Compared with the prior art, the present invention has the following advantages:

1) The present invention can take advantage of the advantages of oil-soluble DDP-Cu nanoparticles with small particle size, uniform size and good anti-friction and anti-wear properties;

2) In the present invention, the oil-soluble DDP-Cu nanoparticles are transferred to the water phase by coating the silica shell layer. The silica shell layer itself has good friction-reducing and anti-wear properties, and the surface of the silica shell layer There are a large number of Si-OH (polar groups), which help to significantly increase the dispersion stability of nanoparticles in water-based lubricants;

3) In the present invention, the oil-soluble DDP-Cu nanoparticles are transferred to the water phase by coating with the silica shell layer, and the silica shell layer can effectively prevent the oxidation of the copper nanoparticles, so that the prepared water-soluble Cu@SiO ₂ Nanoparticles have excellent oxidation stability;

4) The oil-soluble DDP-Cu nanoparticles used in the present invention can be produced on a large scale, and the preparation process equipment adopted in the present invention is simple, and the raw materials are cheap and easy to obtain, so it is expected to prepare water-soluble Cu@SiO ₂ nanoparticles on a large scale.

Description of drawings

Fig. 1 is the transmission electron micrograph of the oil-soluble DDP-Cu nanoparticle that is used in the preparation of Example 1 of the present invention;

Fig. 2 is a transmission electron micrograph of the water-soluble Cu@SiO ₂ nanoparticles prepared in Example 1 of the present invention;

Fig. 3 is an optical photograph of the dispersion of water-soluble Cu@SiO nanoparticles in distilled water prepared in Example ₁ of the present invention;

Fig. 4 shows the tribological experimental results obtained by testing the water-soluble Cu@SiO ₂ nanoparticles prepared in Example 1 of the present invention through a friction testing machine.

Detailed ways

The present invention will be described in detail below in conjunction with specific examples. It must be pointed out that this example is only used to further illustrate the present invention and should not be construed as limiting the protection scope of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention above are deemed to be within the protection scope of the present invention.

In the following examples, the amounts of each raw material are in parts by weight.

Example 1

A water-soluble Cu@ _SiO2 nanoparticle, which is prepared from the following raw materials in parts by weight: 0.1 part of DDP-Cu nanoparticle, 60 parts of cyclohexane, 5 parts of Igepal CO-520, 0.5 part of TEOS, 0.1 part of ammonia water, 0.2 parts of distilled water

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles specifically includes the following steps:

1) Add 0.1 part of oil-soluble DDP-Cu nanoparticles to 60 parts of cyclohexane to form a mixed solution, transfer the mixed solution to a three-necked flask, and under an inert gas atmosphere (the three-necked flask is pre-exhausted with an inert gas to exclude oxygen) and stir for 20 minutes to mix uniformly to obtain a mixed solution a;

2) Add 5 parts of surfactant Igepal CO-520 to the mixed solution a obtained in step 1), stir and react at room temperature for 20 minutes to obtain mixed solution b;

3) Add 0.5 parts of TEOS to the mixed solution b obtained in step 2), stir and react at room temperature for 20 minutes to obtain mixed solution c;

4) Add 0.1 part of ammonia water and 0.2 part of distilled water to the mixed solution c obtained in step 3), stir and react for 12 h; centrifuge after the reaction, wash and dry.

FIG. 1 is a transmission electron micrograph of the oil-soluble DDP-Cu nanoparticles prepared in Example 1; FIG. 2 is a transmission electron micrograph of the water-soluble Cu@SiO ₂ nanoparticles prepared in Example 1. It can be seen from Figure 1 that the oil-soluble DDP-Cu nanoparticles have a small particle size and are very uniformly dispersed, with an average particle size of about 4 nm. It can be seen from Fig. 2 that the prepared water-soluble Cu@SiO ₂ nanoparticles are in good spherical shape with uniform particle size and good dispersion. The oil-soluble DDP-Cu nanoparticles are well coated in the silica spheres, and aggregation does not occur in the silica spheres.

Example 2

A water-soluble Cu@ _SiO2 nanoparticle, which is prepared from the following raw materials in parts by weight: 0.5 parts of DDP-Cu nanoparticles, 65 parts of cyclohexane, 7 parts of Igepal CO-520, 1 part of TEOS, 0.3 parts of ammonia water, 0.9 parts of distilled water

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles specifically includes the following steps:

1) Add 0.5 parts of oil-soluble DDP-Cu nanoparticles to 65 parts of cyclohexane to form a mixed solution, transfer the mixed solution to a three-necked flask, and under an inert gas atmosphere (the three-necked flask is pre-exhausted with an inert gas to exclude oxygen) and stir for 10 minutes to mix uniformly to obtain mixed solution a;

2) Add 7 parts of surfactant Igepal CO-520 to the mixed solution a obtained in step 1), and stir and react at room temperature for 10 minutes to obtain mixed solution b;

3) Add 1 part of TEOS to the mixed solution b obtained in step 2), and stir and react at room temperature for 10 minutes to obtain mixed solution c;

4) Add 0.3 parts of ammonia water and 0.9 parts of distilled water to the mixed solution c obtained in step 3), stir and react for 17 hours; centrifuge after the reaction, wash and dry.

Example 3

A water-soluble Cu@ _SiO2 nanoparticle, which is prepared from the following raw materials in parts by weight: 0.8 parts of DDP-Cu nanoparticles, 72 parts of cyclohexane, 9 parts of Igepal CO-520, 1.5 parts of TEOS, 0.9 parts of ammonia water, 1.7 parts of distilled water

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles specifically includes the following steps:

1) Add 0.8 parts of oil-soluble DDP-Cu nanoparticles to 72 parts of cyclohexane to form a mixed solution, transfer the mixed solution to a three-necked flask, and under an inert gas atmosphere (the three-necked flask is pre-exhausted with an inert gas to exclude oxygen) and stir for 20 minutes to mix uniformly to obtain a mixed solution a;

2) Add 9 parts of surfactant Igepal CO-520 to the mixed solution a obtained in step 1), and stir and react at room temperature for 20 minutes to obtain mixed solution b;

3) Add 1.5 parts of TEOS to the mixed solution b obtained in step 2), stir and react at room temperature for 20 minutes to obtain mixed solution c;

4) Add 0.9 parts of ammonia water and 1.7 parts of distilled water to the mixed solution c obtained in step 3), stir and react for 26 hours; centrifuge after the reaction, wash and dry.

Example 4

A water-soluble Cu@ _SiO2 nanoparticle, which is prepared from the following raw materials in parts by weight: 1 part of DDP-Cu nanoparticle, 83 parts of cyclohexane, 10 parts of Igepal CO-520, 5 parts of TEOS, 1.9 parts of ammonia water, 2.5 parts of distilled water

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles specifically includes the following steps:

1) Add 1 part of oil-soluble DDP-Cu nanoparticles to 83 parts of cyclohexane to form a mixed solution, transfer the mixed solution to a three-necked flask, and under an inert gas atmosphere (the three-necked flask is pre-exhausted with an inert gas to exclude oxygen) and stir for 30 minutes to mix uniformly to obtain a mixed solution a;

2) Add 10 parts of surfactant Igepal CO-520 to the mixed solution a obtained in step 1), and stir and react at room temperature for 30 minutes to obtain mixed solution b;

3) Add 5 parts of TEOS to the mixed solution b obtained in step 2), stir and react at room temperature for 30 minutes to obtain mixed solution c;

4) Add 1.9 parts of ammonia water and 2.5 parts of distilled water to the mixed solution c obtained in step 3), stir and react for 32 hours; centrifuge after the reaction, wash and dry to obtain the product.

Example 5

A water-soluble Cu@ _SiO2 nanoparticle, which is prepared from the following raw materials in parts by weight: 1.5 parts of DDP-Cu nanoparticle, 89 parts of cyclohexane, 12 parts of Igepal CO-520, 6 parts of TEOS, 2.3 parts of ammonia water, 3.9 parts of distilled water

The preparation method of the above-mentioned water-soluble Cu@ _SiO2 nanoparticles specifically includes the following steps:

1) Add 1.5 parts of oil-soluble DDP-Cu nanoparticles to 89 parts of cyclohexane to form a mixed solution, transfer the mixed solution to a three-necked flask, and under an inert gas atmosphere (the three-necked flask is pre-exhausted with an inert gas to exclude oxygen) and stir for 30 minutes to mix uniformly to obtain a mixed solution a;

2) Add 12 parts of surfactant Igepal CO-520 to the mixed solution a obtained in step 1), and stir and react at room temperature for 30 minutes to obtain mixed solution b;

3) Add 6 parts of TEOS to the mixed solution b obtained in step 2), stir and react at room temperature for 30 minutes to obtain mixed solution c;

4) Add 2.3 parts of ammonia water and 3.9 parts of distilled water to the mixed solution c obtained in step 3), stir and react for 38 hours; centrifuge after the reaction, wash and dry to obtain the product.

Application test:

Figure 3 is an optical photograph of the water-soluble Cu@ _SiO2 nanoparticles dispersed in distilled water (right picture) and oil-soluble DDP-Cu nanoparticles dispersed in cyclohexane (left picture) prepared in Example 1 of the present invention (still 1 month), it can be seen from Figure 3 that the oil-soluble DDP-Cu nanoparticles are completely transferred to the water phase after being coated with silica, and can exist stably in the water phase medium.

Figure 4 shows the tribological performance test results of the water-soluble Cu@SiO ₂ nanoparticles prepared in Example 1 of the present invention as a water-based lubricant additive (instrument model UMT-2, American CETR company, amplitude: 5 mm; frequency: 2 Hz; Load: 4 N; Test time: 30 min).

It can be seen from Figure 4a that the friction coefficient of pure distilled water is 0.3902; after adding 0.2wt% of Cu@SiO ₂ nanoparticles prepared in Example 1, the friction coefficient is reduced from 0.3902 to 0.2103, a decrease of 46.10%; adding 0.4wt% % After Cu@SiO ₂ nanoparticles prepared in Example 1, the friction coefficient decreased from 0.3902 to 0.171, a decrease of 56.18%; after adding 0.6wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the friction coefficient decreased from 0.3902 Reduced to 0.1965, reduced by 49.64%; after adding 0.8wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the friction coefficient was reduced from 0.3902 to 0.2265, reduced by 41.95%; added 1.0wt% prepared in Example 1 After adding Cu@SiO ₂ nanoparticles, the friction coefficient decreased from 0.3902 to 0.3052, which was reduced by 21.78%. Through comparison, it was found that the Cu@SiO ₂ nanoparticles prepared by the present invention had good friction-reducing properties.

It can be seen from Figure 4b that the wear volume of pure distilled water is 1.05×10 ^-4 mm ³ /N m; after adding 0.2wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the wear volume increases from 1.05×10 ^-4 mm ³ /N·m decreased to 6.24×10 ^-6 mm ³ /N·m, a decrease of 94.06%; after adding 0.4wt% of Cu@SiO ₂ nanoparticles prepared in Example 1, the wear volume increased from 1.05× 10 ^-4 mm ³ /N·m was reduced to 6.87×10 ^-6 mm ³ /N·m, a decrease of 93.46%; after adding 0.6wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the wear volume was reduced from 1.05 ×10 ^-4 mm ³ /N·m decreased to 7.27×10 ^-6 mm ³ /N·m, a decrease of 93.08%; after adding 0.8wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the wear volume decreased from 1.05×10 ^-4 mm ³ /N·m decreased to 1.17×10 ^-5 mm ³ /N·m, a decrease of 88.86%; after adding 1.0wt% Cu@SiO ₂ nanoparticles prepared in Example 1, the wear volume From 1.05×10 ^-4 mm ³ /N·m to 1.91×10 ^-5 , a decrease of 81.81%. Through comparison, it is found that the Cu@SiO ₂ nanoparticles prepared by the present invention have good anti-wear properties.

Tribological tests were also performed on the water-soluble Cu@SiO ₂ nanoparticles prepared in Examples 2 to 5. The experimental results show that the performance of the products prepared in Examples 2 to 5 is equivalent to the anti-friction and anti-wear properties of the water-soluble Cu@SiO ₂ nanoparticles prepared in Example 1, that is, the friction coefficient can be effectively reduced, the wear volume can be reduced, and the Improving the tribological properties of distilled water has a good application prospect.

In summary, it can be seen that the present invention successfully transfers the oil-soluble DDP-Cu nanoparticles to the aqueous medium by coating with the silica shell layer; the prepared water-soluble Cu@SiO ₂ nanoparticles have good morphology and uniform size, And it has good dispersion stability. When used as a water-based lubricating additive, it can effectively improve the anti-friction and anti-wear properties of distilled water. The invention provides a new idea for preparing water-soluble nanoparticles, and has excellent development prospects.

Claims (5)

1. A water-soluble Cu@ _SiO2 nanoparticle, characterized in that the water-soluble Cu@ _SiO2 nanoparticle is mainly made of the following raw materials in parts by weight: Surface modification oil-soluble nano-copper 0.1-2 parts, Cyclohexane 60～90 parts, Igepal CO-520 5~15 parts, 0.5-7 parts of TEOS, Ammonia 0.1~3 parts, 0.2 to 5 parts of distilled water. 2. The method for preparing water-soluble Cu@ _SiO2 nanoparticles according to claim 1, characterized in that, comprising the following steps: 1) Take each raw material in proportion, and mix the surface-modified oil-soluble nano-copper and cyclohexane evenly to obtain a mixed solution a; 2) Add Igepal CO-520 to the mixed solution a obtained in step 1), stir and react to obtain mixed solution b; 3) Add TEOS to the mixed solution b obtained in step 2), stir and react to obtain mixed solution c; 4) Add ammonia water and distilled water to the mixed solution c obtained in step 3), stir and react for 12-40 h; after the reaction, centrifuge, wash and dry. 3. The method for preparing water-soluble Cu@SiO ₂ nanoparticles according to claim 2, characterized in that, in step 1), uniform mixing is carried out by mixing and stirring at room temperature, and the mixing and stirring time is 5-30 min. 4. The method for preparing water-soluble Cu@SiO ₂ nanoparticles according to claim 2, characterized in that, in steps 2) and 3), the stirring reaction is carried out at room temperature, and the stirring reaction time is 5-30 min. 5. The application of the water-soluble Cu@SiO ₂ nanoparticles as claimed in claim 1 as a water-based lubricating additive.