High latent heat liquid metal phase change microcapsule, and preparation method and application thereof

Abstract

The application provides a high latent heat liquid metal phase change microcapsule and a preparation method and application thereof. The high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fractions: liquid metal: 400-600 parts, nucleating agent: 1-5 parts, surfactant: 20-50 parts, shell material precursor: 30-60 parts, and catalyst: 1500-2000 parts. The preparation method is simple, the raw materials are cheap and easy to obtain, the raw material consumption is small, the cost is low, and the market demand can be met. The obtained liquid metal phase change microcapsule has excellent latent heat performance, can effectively reduce the working temperature of components and devices, and improves the stability and reliability of instruments and equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thermal management, in particular to a high latent heat liquid metal phase change microcapsule and a preparation method and application thereof. BACKGROUND

[0002] With the development of electronic technology and the integration of electronic products, the heat flux density in electronic components is getting higher and higher, and the heat dissipation requirement of electronic components is getting higher and higher. The working temperature of the components in the electronic equipment is too high, which reduces the service life and performance of the instrument equipment. The phase change microcapsule can store or release a large amount of latent heat during the phase change and fill the interface gap, effectively reducing the working temperature of the components and improving the stability and reliability of the instrument equipment, and is widely used in electronic device thermal management.

[0003] Chinese patent document CN104449588A discloses a low melting point metal heat absorbing solution, wherein the dispersed phase in the dispersion system is a phase change microcapsule, and the dispersion medium is oil, water or alcohol. The phase change microcapsule is made of a high molecular polymer as a wall material and a low melting point metal as a core material. The low melting point metal has high latent heat of phase change and high thermal conductivity. The low melting point metal heat absorbing solution can quickly absorb the heat of a high temperature object (liquid or solid), so that the high temperature object can be quickly cooled to the required temperature. However, the wall material of the present application is a high molecular polymer, which has very poor thermal conductivity and seriously hinders heat transfer.

[0004] At present, the preparation of liquid metal microcapsules has problems such as huge consumption of raw materials, complex preparation process, etc., which leads to high production cost and high price of liquid metal microcapsules, and it is difficult to meet the needs of the majority of electronic products. Therefore, it is of great significance to provide a liquid metal microcapsule with cheap and easily available raw materials, simple preparation process, low cost and excellent latent heat performance. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a high latent heat liquid metal phase change microcapsule and a preparation method and application thereof. The preparation method of the present application is simple, the raw materials are cheap and easily available, the consumption of raw materials is small, and the cost is low, which can meet the market demand. The obtained liquid metal phase change microcapsule has excellent latent heat performance, can effectively reduce the working temperature of the components, and improve the stability and reliability of the instrument equipment.

[0006] The technical scheme of the present application is as follows:

[0007] A high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fraction: liquid metal: 400-600 parts, nucleating agent: 1-5 parts, surfactant: 20-50 parts, shell material precursor: 30-60 parts, and catalyst: 1500-2000 parts.

[0008] According to the application, the high latent heat liquid metal phase change microcapsule is prepared by using the following raw materials in mass fraction: liquid metal 450-550 parts, nucleating agent 2-4.2 parts, surfactant 25-40 parts, shell material precursor 45-50 parts, and catalyst 1800-1850 parts.

[0009] Preferably, the high latent heat liquid metal phase change microcapsule is prepared by using the following raw materials in mass fraction: liquid metal 500 parts, nucleating agent 2.5 parts, surfactant 30 parts, shell material precursor 46 parts, and catalyst 1820 parts.

[0010] According to the application, the liquid metal is one of cesium, gallium, indium, and tin or a combination of two or more thereof.

[0011] According to the application, the nucleating agent is one of iron, copper, tellurium dioxide, calcium oxide, and magnesium oxide or a combination of two or more thereof.

[0012] According to the application, the surfactant is one of hexadecyl trimethyl ammonium bromide, dodecyl dimethyl amine oxide, dopamine hydrochloride, and sodium dodecyl sulfate or a combination of two or more thereof.

[0013] According to the application, the shell material precursor is one of tetraethyl orthosilicate, calcium hydroxide, methyl silicate, and triethoxysilane or a combination of two or more thereof.

[0014] According to the application, the catalyst is one of silver hydroxide, sodium hydroxide, sodium bicarbonate, and ammonia water with a mass concentration of 20-30% or a combination of two or more thereof.

[0015] The preparation method of the high latent heat liquid metal phase change microcapsule comprises the following steps:

[0016] (1) uniformly stirring and mixing the liquid metal and the nucleating agent, then adding them drop by drop into an aqueous solution of the surfactant, and obtaining a mixed solution through micronization;

[0017] (2) uniformly mixing the shell material precursor and the catalyst to obtain a shell layer reactant;

[0018] (3) mixing the mixed solution obtained in step (1) and the shell layer reactant obtained in step (2), then performing a reaction, and finally obtaining the high latent heat liquid metal phase change microcapsule through filtration, washing, and drying.

[0019] According to the application, in step (1), the stirring and mixing of the liquid metal and the nucleating agent is performed in a planetary centrifugal mixer, the stirring and mixing time is 10-20 min, the stirring and mixing temperature is room temperature, and the stirring rate is 800-2000 r / min.

[0020] According to the application, preferably, the mass concentration of the surfactant aqueous solution in step (1) is 5-15%.

[0021] According to the application, preferably, in step (1), the micronization is carried out under ultrasonic condition; the ultrasonic time is 1-2h, the ultrasonic power is 100-800W, preferably the ultrasonic power is 400-500W, more preferably the ultrasonic power is 400W.

[0022] According to the application, preferably, in step (2), the mixing of the shell precursor and the catalyst is carried out at room temperature under stirring for 15-25min, and the stirring rate is 500-2000r / min.

[0023] According to the application, preferably, in step (3), the reaction temperature is room temperature, the reaction time is 1-2h, and the reaction is carried out under stirring at a stirring rate of 800-2000r / min.

[0024] Application of the high latent heat liquid metal phase change microcapsule in thermal management materials and devices.

[0025] The technical features and beneficial effects of the application are as follows:

[0026] 1. The preparation method of the application is simple, the raw materials are cheap and easy to obtain, the consumption of raw materials is low, and the cost is low, which can meet the market demand.

[0027] 2. The liquid metal selected in the application has a large latent heat value and can absorb a large amount of heat during the phase change. The shell material selected in the application is an inorganic material, which has a relatively high thermal conductivity compared with the existing organic shell material microcapsule, and is more conducive to heat transfer. The nucleating agent added in the application reduces the supercooling degree, and the phase change latent heat of the microcapsule is significantly improved, but when a small amount or excessive amount of nucleating agent is added, the effect of reducing supercooling is not obvious.

[0028] 3. In the preparation method of the application, the ultrasonic power of micronization has a great influence on the performance of the microcapsule. When the power is too low, the liquid metal cannot be effectively dispersed into small droplets, and when the power is too high, the particle size of the obtained liquid metal microcapsule is too small, and the heat storage capacity is weak.

[0029] 4. The inorganic shell of the microcapsule in the application can protect the internal liquid metal, solve the problems of easy oxidation and easy leakage, greatly reduce the loss of the liquid metal, and reduce the cost. The liquid metal phase change microcapsule in the application has excellent latent heat performance, and the latent heat value can reach 46.7J / g, which can effectively reduce the working temperature of the component and improve the stability and reliability of the instrument. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1is a DSC curve comparison chart of liquid metal phase change microcapsules prepared in Example 2-3 and Comparative Example 1-2 of the present application. DETAILED DESCRIPTION

[0031] The application will be further described in conjunction with specific examples, but not limited thereto.

[0032] Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0033] Example 1

[0034] A high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fraction: liquid gallium: 500 parts, nucleating agent tellurium dioxide: 2.5 parts, surfactant dopamine hydrochloride: 30 parts, shell material precursor tetraethyl orthosilicate: 46 parts, and catalyst ammonia water with a mass concentration of 25%: 1820 parts.

[0035] The preparation method of the above high latent heat liquid metal phase change microcapsule comprises the following steps:

[0036] S1. Pour 500 parts of liquid metal gallium and 2.5 parts of tellurium dioxide into a planetary centrifugal mixer, and stir at room temperature at 2000 r / min for 10 min;

[0037] S2. Take 30 parts of dopamine hydrochloride and dissolve it in 300 parts of water to prepare a surfactant aqueous solution;

[0038] S3. Add the mixture (liquid) obtained in the above step S1 dropwise to the solution obtained in the above step S2, and perform ultrasonic micronization at a power of 500 W for 1 h;

[0039] S4. Mix 46 parts of tetraethyl orthosilicate with 1820 parts of ammonia water, and stir at room temperature at 600 r / min for 20 min;

[0040] S5. Mix the solution obtained in the above step S3 with the solution obtained in step S4, and stir at room temperature at 1200 r / min for 2 h;

[0041] S6. Filter, wash and dry the mixture obtained in the above step S5 reaction to obtain the high latent heat liquid metal microcapsule.

[0042] The latent heat value of the liquid metal phase change microcapsule prepared in this example is 38.5 J / g.

[0043] Example 2

[0044] A high latent heat liquid metal phase change microcapsule is prepared from the raw material composition as described in Example 1;

[0045] The preparation method of the high latent heat liquid metal phase change microcapsule is as described in Example 1, except that the ultrasonic power in S3 is 400 W; and the other steps and conditions are the same as in Example 1.

[0046] The liquid metal phase change microcapsule prepared in the example has a melting point of 30.9℃ and a latent heat value of 46.7J / g.

[0047] Example 3

[0048] A high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fraction: liquid gallium: 500 parts, nucleating agent tellurium dioxide: 4.2 parts, surfactant dopamine hydrochloride: 30 parts, shell material precursor tetraethyl orthosilicate: 46 parts, and catalyst ammonia water with a mass concentration of 25%: 1820 parts.

[0049] The preparation method of the high latent heat liquid metal phase change microcapsule is as described in Example 2.

[0050] The liquid metal phase change microcapsule prepared in the example has a melting point of 30.7℃ and a latent heat value of 34.7J / g.

[0051] Comparative Example 1

[0052] A high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fraction: liquid gallium: 500 parts, nucleating agent tellurium dioxide: 4.2 parts, surfactant dopamine hydrochloride: 30 parts, shell material precursor tetraethyl orthosilicate: 46 parts, and catalyst ammonia water with a mass concentration of 25%: 1820 parts.

[0053] The preparation method of the high latent heat liquid metal phase change microcapsule is as described in Example 2, except that no nucleating agent is added; and the other steps and conditions are the same as in Example 2.

[0054] Comparative Example 2

[0055] A high latent heat liquid metal phase change microcapsule is prepared from the following raw materials in mass fraction: liquid gallium: 500 parts, nucleating agent tellurium dioxide: 4.2 parts, surfactant dopamine hydrochloride: 30 parts, shell material precursor tetraethyl orthosilicate: 46 parts, and catalyst ammonia water with a mass concentration of 25%: 1820 parts.

[0056] The preparation method of the high latent heat liquid metal phase change microcapsule is as described in Example 2.

[0057] Test Example

[0058] The DSC curves of the liquid metal phase change microcapsules prepared in Examples 2-3 and Comparative Examples 1-2 are shown in FIG. 1. Figure 1 When no nucleating agent is added and when the nucleating agent is excessive, no endothermic peak appears in the microcapsules, the former is due to the nanometer effect of the liquid metal, and the latter is because the excessive nucleating agent destroys the original crystal lattice structure of the liquid metal, causing its properties to change.

Claims

1. A high latent liquid metal phase change microcapsule, characterized by, The raw materials are prepared by including the following mass parts: liquid metal: 500 parts, nucleating agent: 2.5 parts, surfactant: 30 parts, shell material precursor: 46 parts, catalyst: 1820 parts; The liquid metal is gallium; the nucleating agent is tellurium dioxide; the surfactant is dopamine hydrochloride; the shell material precursor is tetraethyl orthosilicate; and the catalyst is ammonia water with a mass concentration of 25%; The preparation method of the high latent heat liquid metal phase change microcapsule comprises the following steps: S1. Pour 500 parts of liquid metal gallium and 2.5 parts of tellurium dioxide into a planetary centrifugal mixer, and stir at 2000 r / min at room temperature for 10 min; S2. Take 30 parts of dopamine hydrochloride and dissolve it in 300 parts of water to prepare a surfactant aqueous solution; S3. Add the mixture obtained in step S1 dropwise to the solution obtained in step S2, and perform ultrasonic micronization at a power of 500 W for 1 h; S4. Take 46 parts of tetraethyl orthosilicate and mix it with 1820 parts of ammonia water, and stir at 600 r / min at room temperature for 20 min; S5. Mix the solution obtained in step S3 with the solution obtained in step S4, and stir at 1200 r / min at room temperature for 2 h; S6. Filter, wash and dry the mixture obtained in step S5, and finally obtain the high latent heat liquid metal microcapsule.

2. The application of the high latent heat liquid metal phase change microcapsule in claim 1 in thermal management materials and devices.

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