Method for preparing nano tin particles through liquid phase reduction method
By using ascorbic acid and PVP/PEG at room temperature to inhibit the hydrolysis of tin salt solution, combined with liquid phase reduction method of mixed reducing agent and dispersant, the problems of hydrolysis and oxidation reaction in the preparation of nanotin particles were solved, and high conversion and dispersion were achieved Nanotin powder preparation, suitable for large-scale production.
Patent Information
- Application Number
- CN202411443826.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2025-01-17
AI Technical Summary
The traditional method of preparing nanotin particles has problems such as complex process, high cost, low yield, uneven size and degradation of tin particles. In practical applications, liquid phase reduction method also has hydrolysis and oxidation reactions that lead to low conversion of tin salts. question.
Under room temperature, the hydrolysis of the tin salt solution is inhibited by ascorbic acid, and PVP and low molecular weight PEG are added to control the ratio of PVP and PEG to ensure solution stability and particle size uniformity. The liquid phase of mixed reducing agents and dispersants is used to use The reduction method is used to obtain nanotin particles through dropwise addition reaction, and the entire process is carried out under the water system.
The preparation of high-quality nanotin powder at room temperature is achieved. The conversion rate of tin atoms is as high as 96%, with excellent dispersion and antioxidant properties, suitable for large-scale production and simple operation.
Smart Images
Figure CN119319255A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of tin powder preparation, and in particular to a liquid phase reduction method for preparing nano tin particles. Background Art
[0002] Nano-tin particles have broad application prospects in the fields of electronics, catalysis, energy storage, etc. due to their unique physical and chemical properties. Traditional methods for preparing nano-tin particles include vapor deposition and solid-phase reaction, but these methods usually have problems such as complex process, high cost, and low yield. Liquid phase reduction method has become an effective method for preparing nano-tin particles due to its advantages such as simple operation, low cost, and easy control. However, there are still many problems in the practical application of liquid phase reduction method for preparing nano-tin particles:
[0003] The existing technology usually relies on a single reducing agent and dispersant, which leads to uneven size of tin particles and reduced product performance; after a single reducing agent is added dropwise to a tin salt solution, the reducing agent diffuses slowly in the tin salt solution, and some of the generated nano-tin particles will agglomerate; the tin salt solution to be reduced is prone to hydrolysis and oxidation reactions, resulting in a low tin salt conversion rate; some methods also require conditions such as high temperature and high pressure, which increases costs and energy consumption. Summary of the invention
[0004] The invention provides a method for preparing nano tin particles by a liquid phase reduction method. The invention proposes a new technical scheme. Under room temperature conditions, ascorbic acid is used to inhibit the hydrolysis of a tin salt solution, and PVP and low-molecular-weight PEG are added at the same time. The ratio of PVP and PEG is controlled to maintain the stability of the solution while ensuring the uniformity of particle size distribution. Then, the nano tin particles are obtained by a mixed solution of a reducing agent and a dispersant. In this process, high-quality tin powder that can be mass-produced is prepared by regulating appropriate process parameters. The entire reaction is carried out in a water system.
[0005] The technical solution adopted by the present invention is: a liquid phase reduction method for preparing nano-tin particles, comprising the following steps:
[0006] Step 1: adding ascorbic acid to an aqueous solvent and mixing uniformly to obtain a solution A; then adding a pre-dispersant and a tin salt in a mass ratio of 1:2 to 1:3.5 to the solution A and mixing uniformly to obtain a solution B; wherein the mass ratio of ascorbic acid to the tin salt is 1:5 to 1:7;
[0007] Step 2: adding a reducing agent and a dispersing agent to an aqueous solvent and mixing them uniformly to obtain a solution C; wherein the mass ratio of the dispersing agent to the tin salt is 1:4 to 1:5, and the mass ratio of the reducing agent to the tin salt is 1:1.4 to 1:2;
[0008] Step 3, adding solution C dropwise into solution B at a dropping rate of 3.5 mL / min, reacting for 90 to 150 minutes, to obtain solution D;
[0009] Step 4, separating the solution D into solid and liquid, washing with water, washing with alcohol and drying to obtain nano-tin powder.
[0010] In the step 1, the mass ratio of the pre-dispersant to the tin salt is 1:2.5.
[0011] In the step 1, the mass ratio of ascorbic acid to tin salt is 1:6.
[0012] The concentration of the tin salt solution in step 1 is 150-170 g / L.
[0013] The mass ratio of the dispersant to the tin salt in the step 2 is 1:5.
[0014] The mass ratio of the reducing agent to the tin salt in the step 2 is 1:2.
[0015] In the step 1, the pre-dispersing agent is polyvinyl pyrrolidone and polyethylene glycol, the mass ratio of polyvinyl pyrrolidone to polyethylene glycol is 1:1, and the molecular weight of the polyethylene glycol is 400-2000.
[0016] In the step 1, the tin salt is one or more of stannous sulfate or stannous chloride.
[0017] The reducing agent in step 2 is one or more of hydrazine hydrate, formaldehyde or sodium borohydride.
[0018] The dispersant in step 2 is one or more of sodium citrate, polyvinyl pyrrolidone, polyethylene glycol, and phenanthroline hydrochloride.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. The entire reaction process is carried out at room temperature in a water system, the operation is simple, and it is suitable for large-scale production with stable quality.
[0021] 2. The present invention uses a step-by-step liquid phase reduction method to adjust the morphology of nano-tin particles by controlling the mass ratio of the pre-dispersant, ascorbic acid, dispersant, reducing agent and tin salt. The aqueous solution of ascorbic acid is acidic, which can control the hydrolysis reaction of the tin salt solution and reduce the reduction potential at the same time, thereby preparing nano-tin powder with excellent performance.
[0022] 3. The pre-dispersant is a mixture of polyvinyl pyrrolidone and polyethylene glycol. Polyethylene glycol has a relatively low molecular weight and is permeable. Polyvinyl pyrrolidone is adsorbed on the surface of nano-tin under the action of hydrogen bonds to form a protective film to prevent agglomeration. The low molecular weight polyethylene glycol can make the nano-tin have better hydrophilicity through physical adsorption. Under the joint action of polyvinyl pyrrolidone and polyethylene glycol, the dispersibility of nano-tin is further enhanced, which is beneficial to the preparation of nano-tin powder. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is an electron microscope image of the nano-tin powder described in Example 1.
[0024] Figure 2 This is a local magnified electron microscope image of the nano-tin powder described in Example 1.
[0025] Figure 3 This is an electron microscope image of the nano-tin powder described in Comparative Example 1. DETAILED DESCRIPTION
[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] Example 1
[0028] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0029] 25g PVP and 62g sodium borohydride were added to 800mL deionized water respectively, stirred for 30min to obtain a reduction solution, and the reduction solution was added dropwise to the pre-reduction solution at a drop rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to settle. The obtained sample was washed with water and alcohol for several times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano-tin powder. The electron microscope image of the nano-tin powder in the embodiment is as follows Figure 1 and Figure 2 shown.
[0030] Example 2
[0031] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 25 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 minutes to obtain a pre-reduced solution;
[0032] 25g PVP and 62g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0033] Example 3
[0034] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, and a pre-dispersant and stannous chloride are added in sequence, wherein the pre-dispersant is 18 g of PVP and 18 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0035] 25g PEG-1000 and 62g sodium borohydride were added to 800mL deionized water respectively, and stirred for 30min to obtain a reducing solution. The reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, and treated in a vacuum oven at 50°C for 6h. The dried sample was crushed and ground to obtain nano-tin powder.
[0036] Example 4
[0037] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 30 g of PVP and 30 g of PEG-800, and stirred for 30 min to obtain a pre-reduction solution;
[0038] 25g PVP and 62g formaldehyde were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0039] Example 5
[0040] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0041] 30g PVP and 62g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0042] Example 6
[0043] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0044] 25 g of phylloline hydrochloride and 86 g of sodium borohydride were added to 800 mL of deionized water respectively, and stirred for 30 min to obtain a reducing solution. The reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5 mL / min at room temperature. After the addition was completed, the mixture was reacted for 120 min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6 h, and the dried sample was crushed and ground to obtain nano tin powder.
[0045] Example 7
[0046] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0047] 25g PVP and 75g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0048] Example 8
[0049] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 15 g of PVP and 35 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0050] 25 g of sodium citrate and 62 g of sodium borohydride were respectively added to 800 mL of deionized water, stirred for 30 min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5 mL / min at room temperature. After the addition was completed, the mixture was reacted for 120 min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6 h, and the dried sample was crushed and ground to obtain nano tin powder.
[0051] Example 9
[0052] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 35 g of PVP and 15 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0053] 25g PVP and 62g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0054] Comparative Example 1
[0055] A method for preparing nano-tin particles by liquid phase reduction method, preparing 800 mL of deionized water, adding a pre-dispersant and stannous chloride in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, stirring for 30 minutes to obtain a pre-reduced solution;
[0056] 25g PVP and 62g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0057] Comparative Example 2
[0058] A method for preparing nano-tin particles by liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, 123 g of stannous chloride is added, and stirred for 30 minutes to obtain a pre-reduction solution;
[0059] 25g PVP and 62g hydrazine hydrate were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0060] Comparative Example 3
[0061] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 20 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0062] 62 g of formaldehyde was added to 800 mL of deionized water and stirred for 30 min to obtain a reducing solution. The reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5 mL / min at room temperature. After the addition was completed, the mixture was reacted for 120 min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6 h, and the dried sample was crushed and ground to obtain nano tin powder.
[0063] Comparative Example 4
[0064] A method for preparing nano-tin particles by a liquid phase reduction method, wherein 60 g of ascorbic acid is added to 800 mL of water, mixed and stirred, a pre-dispersant and stannous chloride are added in sequence, the pre-dispersant is 25 g of PVP and 25 g of PEG-800, and stirred for 30 min to obtain a pre-reduced solution;
[0065] 25g PVP and 62g sodium borohydride were added to 800mL deionized water respectively, stirred for 30min to obtain a reducing solution, and the reducing solution was added dropwise to the pre-reducing solution at a dropping rate of 3.5mL / min at room temperature. After the addition was completed, the mixture was reacted for 120min while stirring, and allowed to stand for sedimentation. The obtained sample was washed with water and alcohol for multiple times, treated in a vacuum oven at 50°C for 6h, and the dried sample was crushed and ground to obtain nano tin powder.
[0066] The calculation formula of tin conversion rate is as follows:
[0067]
[0068] CR is the tin conversion rate; m1 is the actual output mass of tin; m2 is the theoretical output mass of tin; m3 is the mass of tin salt; M1 is the relative molecular mass of tin; M2 is the relative molecular mass of tin salt.
[0069] The morphology of the nano-tin powder was characterized and tested, as shown in Table 1.
[0070] Table 1
[0071]
[0072] Conclusion: The present invention discloses a method for preparing nano-tin particles by a liquid phase reduction method. The process steps are simple and the process parameters are appropriate. Nano-tin powder is prepared in a water system. The conversion rate of tin atoms is as high as 96%. The method has high dispersibility and crystallinity and excellent antioxidant performance in the air. The particle size of the nano-tin powder is mainly distributed in the range of 60nm to 300nm, which is suitable for large-scale production and has stable quality.
[0073] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.
Claims
1. A liquid phase reduction method for preparing nano-tin particles, characterized in that: The following steps are involved: Step 1: adding ascorbic acid to an aqueous solvent and mixing uniformly to obtain a solution A; then adding a pre-dispersant and a tin salt in a mass ratio of 1:2 to 1:3.5 to the solution A and mixing uniformly to obtain a solution B; wherein the mass ratio of ascorbic acid to the tin salt is 1:5 to 1:7; Step 2: adding a reducing agent and a dispersing agent to an aqueous solvent and mixing them uniformly to obtain a solution C; wherein the mass ratio of the dispersing agent to the tin salt is 1:4 to 1:5, and the mass ratio of the reducing agent to the tin salt is 1:1.4 to 1:2; Step 3, adding solution C dropwise into solution B at a dropping rate of 3.5 mL / min, reacting for 90 to 150 minutes, to obtain solution D; Step 4, separating the solution D into solid and liquid, washing with water, washing with alcohol and drying to obtain nano-tin powder.
2. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: In the step 1, the mass ratio of the pre-dispersant to the tin salt is 1:2.
5.
3. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: In the step 1, the mass ratio of ascorbic acid to tin salt is 1:
6.
4. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: The concentration of the tin salt solution in step 1 is 150-170 g / L.
5. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: The mass ratio of the dispersant to the tin salt in the step 2 is 1:
5.
6. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: The mass ratio of the reducing agent to the tin salt in the step 2 is 1:
2.
7. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: In the step 1, the pre-dispersing agent is polyvinyl pyrrolidone and polyethylene glycol, the mass ratio of polyvinyl pyrrolidone to polyethylene glycol is 1:1, and the molecular weight of the polyethylene glycol is 400-2000.
8. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: In the step 1, the tin salt is one or more of stannous sulfate or stannous chloride.
9. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: The reducing agent in step 2 is one or more of hydrazine hydrate, formaldehyde or sodium borohydride.
10. The method for preparing nano-tin particles by liquid phase reduction according to claim 1, characterized in that: The dispersant in step 2 is one or more of sodium citrate, polyvinyl pyrrolidone, polyethylene glycol, and phenanthroline hydrochloride.