Method for preparing solid hydrogen peroxide particles

Abstract

The invention relates to the technical field of disinfection and disinfection, in particular to a method for preparing solid hydrogen peroxide particles. The method comprises the following steps: (1) adding sodium alginate and chitosan into deionized water, uniformly stirring, cooling, adding a hydrogen peroxide aqueous solution, sodium pyrophosphate and sodium phytate, and stirring to form a hydrogen peroxide mixed solution; (2) preparing a solid hydrogen peroxide block from the mixed solution by a freeze-drying method; and (3) crushing the solid hydrogen peroxide block in a nitrogen atmosphere, and sieving to obtain solid hydrogen peroxide particles. By means of a gel network structure formed by sodium alginate and chitosan, hydrogen peroxide molecules are effectively wrapped, the thermal stability is improved, decomposition is delayed, and the synergistic effect of sodium pyrophosphate and sodium phytate further optimizes the internal structure of particles and enhances the mechanical strength. The prepared particles show excellent performance in the storage, transportation and use processes, and have wide industrial application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of antivirus and disinfection, and particularly to a method for preparing solid hydrogen peroxide particles. Background Art

[0002] Due to its strong oxidizing property and wide range of bactericidal ability, hydrogen peroxide is widely used in industries, medical treatment, food processing, water treatment and other fields. However, hydrogen peroxide aqueous solution is prone to decomposition during storage and transportation, especially under high-temperature conditions, where its decomposition rate significantly accelerates, resulting in a rapid decline in the effective content and seriously affecting the use effect. To extend the storage period of hydrogen peroxide, researchers have proposed a technical route for solidifying hydrogen peroxide. By preparing hydrogen peroxide into solid particles, its decomposition rate can be significantly reduced, and the storage stability can be improved. However, there are still many technical problems in the preparation and use of existing solid hydrogen peroxide particles.

[0003] Firstly, the thermal stability of existing solid hydrogen peroxide particles is insufficient. Especially under relatively high-temperature conditions, the decomposition rate of hydrogen peroxide is still relatively fast, resulting in a decrease in the effective content of the product during storage and transportation and making it difficult to ensure long-term stability. Secondly, the dissolution performance of the particles is poor, and hydrogen peroxide cannot be rapidly released during use, affecting its use efficiency in industrial and medical fields. In addition, the mechanical strength of the particles is low, and they are prone to breakage during storage and transportation, resulting in particle pulverization, which not only affects the appearance of the product but may also reduce its performance and use effect.

[0004] To overcome the above problems, researchers have tried to improve the performance of solid hydrogen peroxide particles by adding stabilizers and improving the preparation process. For example, adding stabilizers can delay the decomposition of hydrogen peroxide to a certain extent, but the selection and ratio optimization of stabilizers in the existing technology are insufficient, resulting in the thermal stability of the particles still needing to be improved. At the same time, most of the existing preparation processes use simple drying methods, which are difficult to form a uniform particle structure, and the particles perform poorly in terms of dissolution performance and mechanical strength. In addition, how to effectively balance the relationship among thermal stability, dissolution performance, and mechanical strength during particle preparation is still an important problem in the existing technology. Therefore, developing a method that can significantly improve the stability, dissolution performance, and mechanical strength of solid hydrogen peroxide particles has become an urgent problem to be solved in the current technical field. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a method for preparing solid hydrogen peroxide particles to solve the problems of fast decomposition rate, poor dissolution performance, and insufficient mechanical strength existing in existing solid hydrogen peroxide particles.

[0006] Based on the above purpose, the present invention provides a method for preparing solid hydrogen peroxide particles, including the following steps:

[0007] (1) Add sodium alginate and chitosan to deionized water, heat up to 50 - 70 °C, stir for 20 - 40 min, then cool down to 8 - 12 °C, add hydrogen peroxide aqueous solution, sodium pyrophosphate and sodium phytate, and stir for 2 - 4 h to obtain a hydrogen peroxide mixed solution;

[0008] (2) Dispense the hydrogen peroxide mixed solution into a freeze - drying tray, place it in the pre - cooled cavity of a freeze - dryer, cool it at a rate of 1 - 10 °C / min to - 50 ± 2 °C, keep it warm for 3 - 5 h, start the vacuum system to reduce the cavity pressure to 8 - 12 Pa, heat it at a rate of 0.4 - 0.6 °C / min to - 25 ± 2 °C, keep it warm for 20 - 28 h, and finally heat it at a rate of 0.1 - 0.3 °C / min to 25 °C, keep it warm for 10 - 14 h to obtain solid hydrogen peroxide blocks;

[0009] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks and sieve them through an 80 - 120 mesh sieve to obtain solid hydrogen peroxide particles.

[0010] Preferably, in step (1), the weight ratio of sodium alginate, chitosan, hydrogen peroxide aqueous solution, sodium pyrophosphate and sodium phytate is 1 - 2:1.4 - 2.8:40 - 60:500:0.2 - 1:0.1 - 0.3.

[0011] Preferably, the viscosity of sodium alginate in step (1) is 1.0 - 1.2 Pa·s.

[0012] Preferably, the molecular weight of chitosan in step (1) is 80 - 120 kDa, and the degree of deacetylation is 95%.

[0013] Preferably, the concentration of the hydrogen peroxide aqueous solution in step (1) is 30 wt%.

[0014] Preferably, the liquid layer height of the hydrogen peroxide mixed solution in the freeze - drying tray in step (2) is 1 - 2 cm.

[0015] Preferably, the freeze - dryer is pre - cooled to - 40 ± 2 °C in step (2).

[0016] Advantages of the present invention:

[0017] By precisely proportioning sodium alginate, chitosan, sodium pyrophosphate and sodium phytate and optimizing the freeze - drying process, the present invention prepares solid hydrogen peroxide particles with excellent performance, solving the problems of poor particle stability, insufficient dissolution performance and low mechanical strength in the prior art.

[0018] By adding a gel network structure formed by sodium alginate and chitosan, the present invention effectively encapsulates hydrogen peroxide molecules, significantly improves the thermal stability of the particles, and reduces the decomposition risk of hydrogen peroxide during storage and transportation.

[0019] The present invention further enhances the stability of the particles through the synergistic effect of sodium pyrophosphate and sodium phytate, while optimizing the internal structure of the particles, enabling them to rapidly absorb water and uniformly release hydrogen peroxide during the dissolution process, meeting the requirements for rapid reactions in industrial, medical and other fields.

[0020] The present invention optimizes the freeze-drying process, ensures the forming effect and structural uniformity of the particles, significantly improves the mechanical strength of the particles, enhances the compressive resistance of the particles during storage, transportation and operation, and reduces the loss of product performance caused by fragmentation.

[0021] The method for preparing solid hydrogen peroxide particles provided by the present invention shows significant advantages in improving product stability, dissolution performance and mechanical strength, and has broad industrial application value. Detailed Embodiments

[0022] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in conjunction with specific embodiments.

[0023] Example 1:

[0024] (1) Add 1 g of sodium alginate (viscosity 1.1 Pa·s) and 1.4 g of chitosan (molecular weight 100 kDa, degree of deacetylation 95%) to 40 g of deionized water, heat up to 50 °C, stir for 20 min, cool down to 8 °C, add 500 g of an aqueous hydrogen peroxide solution with a concentration of 30 wt%, 0.2 g of sodium pyrophosphate and 0.1 g of sodium phytate, and stir for 2 h to obtain a hydrogen peroxide mixed solution;

[0025] (2) Subdivide the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height of each tray being 1 cm, place it in the freeze-dryer cavity pre-cooled to -42 °C, cool down to -52 °C at a rate of 1 °C / min, keep warm for 3 h, start the vacuum system to reduce the cavity pressure to 8 Pa, heat up to -27 °C at a rate of 0.4 °C / min, keep warm for 20 h, and finally heat up to 25 °C at a rate of 0.1 °C / min and keep warm for 10 h to obtain a solid hydrogen peroxide block;

[0026] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide block and pass it through an 80-mesh sieve to obtain solid hydrogen peroxide particles.

[0027] Example 2:

[0028] (1) Add 1.5 g of sodium alginate (viscosity 1.1 Pa·s) and 2 g of chitosan (molecular weight 100 kDa, deacetylation degree 95%) to 50 g of deionized water. Heat the mixture to 60 °C, stir for 30 min, cool to 10 °C, add 500 g of an aqueous hydrogen peroxide solution with a concentration of 30 wt%, 0.5 g of sodium pyrophosphate, and 0.2 g of sodium phytate, and stir for 3 h to obtain a hydrogen peroxide mixed solution;

[0029] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height in each tray being 1.5 cm. Place the trays in a freeze-dryer chamber pre-cooled to -40 °C, cool at a rate of 5 °C / min to -50 °C, hold for 4 h, start the vacuum system to reduce the chamber pressure to 10 Pa, heat at a rate of 0.5 °C / min to -25 °C, hold for 24 h, and finally heat at a rate of 0.2 °C / min to 25 °C and hold for 12 h to obtain solid hydrogen peroxide blocks;

[0030] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks and pass them through a 100-mesh sieve to obtain solid hydrogen peroxide particles.

[0031] Example 3:

[0032] (1) Add 2 g of sodium alginate (viscosity 1.1 Pa·s) and 2.8 g of chitosan (molecular weight 100 kDa, deacetylation degree 95%) to 60 g of deionized water. Heat the mixture to 70 °C, stir for 40 min, cool to 12 °C, add 500 g of an aqueous hydrogen peroxide solution with a concentration of 30 wt%, 1 g of sodium pyrophosphate, and 0.3 g of sodium phytate, and stir for 4 h to obtain a hydrogen peroxide mixed solution;

[0033] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height in each tray being 2 cm. Place the trays in a freeze-dryer chamber pre-cooled to -38 °C, cool at a rate of 10 °C / min to -48 °C, hold for 5 h, start the vacuum system to reduce the chamber pressure to 12 Pa, heat at a rate of 0.6 °C / min to -23 °C, hold for 28 h, and finally heat at a rate of 0.3 °C / min to 25 °C and hold for 14 h to obtain solid hydrogen peroxide blocks;

[0034] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks and pass them through a 120-mesh sieve to obtain solid hydrogen peroxide particles.

[0035] Comparative Example 1:

[0036] The difference between Comparative Example 1 and Example 2 is that sodium alginate was not added;

[0037] The specific steps are as follows:

[0038] (1) Add 3.5 g of chitosan (molecular weight 100 kDa, deacetylation degree 95%) to 50 g of deionized water, heat up to 60 °C, stir for 30 min, cool down to 10 °C, add 500 g of hydrogen peroxide aqueous solution with a concentration of 30 wt%, 0.5 g of sodium pyrophosphate and 0.2 g of sodium phytate, and stir for 3 h to obtain a hydrogen peroxide mixed solution;

[0039] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height of each tray being 1.5 cm, place it in the freeze-dryer cavity pre-cooled to -40 °C, cool down to -50 °C at a rate of 5 °C / min, keep warm for 4 h, start the vacuum system to reduce the cavity pressure to 10 Pa, heat up to -25 °C at a rate of 0.5 °C / min, keep warm for 24 h, and finally heat up to 25 °C at a rate of 0.2 °C / min and keep warm for 12 h to obtain solid hydrogen peroxide blocks;

[0040] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks through a 100-mesh sieve to obtain solid hydrogen peroxide particles.

[0041] Comparative Example 2:

[0042] The difference between Comparative Example 2 and Example 2 is that chitosan is not added;

[0043] The specific steps are as follows:

[0044] (1) Add 3.5 g of sodium alginate (viscosity 1.1 Pa·s) to 50 g of deionized water, heat up to 60 °C, stir for 30 min, cool down to 10 °C, add 500 g of hydrogen peroxide aqueous solution with a concentration of 30 wt%, 0.5 g of sodium pyrophosphate and 0.2 g of sodium phytate, and stir for 3 h to obtain a hydrogen peroxide mixed solution;

[0045] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height of each tray being 1.5 cm, place it in the freeze-dryer cavity pre-cooled to -40 °C, cool down to -50 °C at a rate of 5 °C / min, keep warm for 4 h, start the vacuum system to reduce the cavity pressure to 10 Pa, heat up to -25 °C at a rate of 0.5 °C / min, keep warm for 24 h, and finally heat up to 25 °C at a rate of 0.2 °C / min and keep warm for 12 h to obtain solid hydrogen peroxide blocks;

[0046] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks through a 100-mesh sieve to obtain solid hydrogen peroxide particles.

[0047] Comparative Example 3:

[0048] The difference between Comparative Example 3 and Example 2 is that sodium pyrophosphate is not added;

[0049] The specific steps are as follows:

[0050] (1) Add 1.5 g of sodium alginate (viscosity 1.1 Pa·s) and 2 g of chitosan (molecular weight 100 kDa, deacetylation degree 95%) to 50 g of deionized water. Heat the mixture to 60 °C, stir for 30 min, cool it to 10 °C, add 500 g of an aqueous hydrogen peroxide solution with a concentration of 30 wt% and 0.7 g of sodium phytate, and stir for 3 h to obtain a hydrogen peroxide mixed solution;

[0051] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height of each tray being 1.5 cm. Place the trays in a freeze-dryer chamber pre-cooled to -40 °C, cool the mixture to -50 °C at a rate of 5 °C / min, keep it at this temperature for 4 h, start the vacuum system to reduce the chamber pressure to 10 Pa, heat the mixture to -25 °C at a rate of 0.5 °C / min, keep it at this temperature for 24 h, and finally heat the mixture to 25 °C at a rate of 0.2 °C / min and keep it at this temperature for 12 h to obtain solid hydrogen peroxide blocks;

[0052] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks and pass them through a 100-mesh sieve to obtain solid hydrogen peroxide particles.

[0053] Comparative Example 4:

[0054] The difference between Comparative Example 4 and Example 2 is that sodium phytate was not added;

[0055] The specific steps are as follows:

[0056] (1) Add 1.5 g of sodium alginate (viscosity 1.1 Pa·s) and 2 g of chitosan (molecular weight 100 kDa, deacetylation degree 95%) to 50 g of deionized water. Heat the mixture to 60 °C, stir for 30 min, cool it to 10 °C, add 500 g of an aqueous hydrogen peroxide solution with a concentration of 30 wt% and 0.7 g of sodium pyrophosphate, and stir for 3 h to obtain a hydrogen peroxide mixed solution;

[0057] (2) Dispense the hydrogen peroxide mixed solution into stainless steel freeze-drying trays, with the liquid layer height of each tray being 1.5 cm. Place the trays in a freeze-dryer chamber pre-cooled to -40 °C, cool the mixture to -50 °C at a rate of 5 °C / min, keep it at this temperature for 4 h, start the vacuum system to reduce the chamber pressure to 10 Pa, heat the mixture to -25 °C at a rate of 0.5 °C / min, keep it at this temperature for 24 h, and finally heat the mixture to 25 °C at a rate of 0.2 °C / min and keep it at this temperature for 12 h to obtain solid hydrogen peroxide blocks;

[0058] (3) Under a nitrogen atmosphere, crush the solid hydrogen peroxide blocks and pass them through a 100-mesh sieve to obtain solid hydrogen peroxide particles.

[0059] Performance test:

[0060] Determination of active content: Accurately weigh 1.000 g of the sample (accurate to 0.1 mg), dissolve it in 100 mL of deionized water, and perform the determination using the potassium permanganate titration method specified in the standard GB / T 1616-2014. Take the arithmetic mean of three parallel tests, and the results are shown in Table 1.

[0061] Thermal stability test: Seal the solid hydrogen peroxide particles prepared in the examples and comparative examples in an aluminum-plastic composite film packaging bag, place them in a constant temperature oven at 60 °C, and take samples to detect the active content on the 7th day, 14th day, and 21st day respectively. Calculate the decomposition rate (decomposition rate = [(initial content - content at the time of testing) / initial content] × 100%), and the results are shown in Table 1.

[0062] Dissolution performance test: Pour 200 mL of deionized water into a beaker, keep it at a constant temperature of 25 °C, take 1.00 g of the sample and place it in a porous sample addition boat, immerse it 1 cm below the liquid surface, stir at a speed of 300 rpm, start timing from the moment of feeding, and record the mass change curve in real time. When the mass change ≤ 0.01 g for 10 consecutive seconds, it is determined to be completely dissolved, record the dissolution time, repeat the test three times and take the average value, and the results are shown in Table 1.

[0063] Particle strength test: Use a texture analyzer to measure, the probe model is P / 0.5, the test speed is 0.5 mm / s, the trigger force is 5 g, record the maximum pressure value when the particles are broken, repeat the test three times and take the average value, and the results are shown in Table 1.

[0064] Table 1 Performance test results

[0065]

[0066] Data analysis:

[0067] From the data of Examples 1-3 in Table 1, it can be seen that the difference between the active content of the solid hydrogen peroxide particles prepared by the present invention and the theoretical active content is less than 0.5%, indicating that the freeze-drying process of the present invention effectively removes moisture and prevents the decomposition of hydrogen peroxide during the preparation process. The decomposition rate on the 21st day at 60 °C is less than 1.2%, indicating its excellent thermal stability, which helps to reduce the decomposition risk during storage and transportation, thereby extending the shelf life of the product. Moreover, the solid hydrogen peroxide particles have a relatively fast dissolution time and high particle strength. The relatively fast dissolution time ensures its efficient release during use, meeting the requirements for rapid reactions in industrial, medical and other fields; the high particle strength effectively improves the compressive resistance and stability of the product during storage, transportation and operation, reducing the performance loss caused by particle breakage.

[0068] From the data of Example 2 and Comparative Examples 1-2 in Table 1, it can be seen that in Example 2, sodium alginate and chitosan were added simultaneously, making the solid hydrogen peroxide particles show significant advantages in terms of effective content, thermal stability, dissolution performance, and particle strength. This may be because sodium alginate and chitosan formed a gel network structure in the system, which could effectively encapsulate hydrogen peroxide molecules and slow down their decomposition rate, thus significantly improving the thermal stability. At the same time, as a polymer material, the amino and hydroxyl groups in the molecular structure of chitosan may further improve the dispersibility of sodium pyrophosphate and sodium phytate in the solid particles through the formation of hydrogen bonds or other weak interactions, thereby enhancing the role of sodium pyrophosphate and sodium phytate in the solid hydrogen peroxide particles. In addition, the synergistic effect of sodium alginate and chitosan may optimize the internal pore structure of the particles, enabling them to quickly absorb water and disperse evenly during the dissolution process, thus significantly shortening the dissolution time. The combination of the two may also enhance the forming effect of the particles during the freeze-drying process, preventing the particles from collapsing or being uneven during drying, thereby improving the mechanical strength of the particles. These results indicate that the synergistic effect of sodium alginate and chitosan is of great significance in enhancing the stability, dissolution performance, and strength of the particles.

[0069] From the data of Example 2 and Comparative Example 3 in Table 1, it can be seen that the introduction of sodium pyrophosphate plays an important role in optimizing the performance of solid hydrogen peroxide particles. Sodium pyrophosphate can significantly slow down the decomposition rate of hydrogen peroxide, thereby improving the thermal stability of the particles. In addition, sodium pyrophosphate may play a role in regulating the crystal structure during the preparation of the particles, making the internal structure of the particles more dense and uniform, thus significantly improving the mechanical strength of the particles. In terms of dissolution performance, sodium pyrophosphate may promote the contact and diffusion between the particles and water by adjusting the hydrophilicity of the particle surface, enabling the particles to absorb water and dissolve evenly more quickly. These mechanisms of action indicate that sodium pyrophosphate can not only improve the storage stability of the particles but also enhance their dissolution performance and mechanical properties.

[0070] From the data of Example 2 and Comparative Example 4 in Table 1, it can be seen that the addition of sodium phytate significantly improves the comprehensive performance of solid hydrogen peroxide particles, especially in terms of thermal stability, dissolution performance, and particle strength. As a multifunctional chelating agent, sodium phytate contains multiple phosphate groups in its molecular structure, which can form weak interactions with the reactive oxygen of hydrogen peroxide molecules, significantly reducing the decomposition rate of hydrogen peroxide, thus improving the thermal stability of the particles. In addition, sodium phytate may regulate the microstructure of the particles, making the internal pore distribution more uniform, thereby enhancing the mechanical strength of the particles. In terms of dissolution performance, sodium phytate may promote the contact between the particles and water by improving the surface characteristics and hydrophilicity of the particles, enabling the particles to absorb water and dissolve evenly quickly, significantly shortening the dissolution time.

[0071] Those of ordinary skill in the art should understand that any discussion of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A method for preparing solid hydrogen peroxide particles, characterized in that: The following steps are involved: (1) adding sodium alginate and chitosan to deionized water, heating to 50-70° C., stirring for 20-40 min, then cooling to 8-12° C., adding aqueous hydrogen peroxide solution, sodium pyrophosphate and sodium phytate, stirring for 2-4 h, and obtaining a hydrogen peroxide mixed solution; (2) The hydrogen peroxide mixed solution is dispensed into a freeze drying tray, placed in a precooled freeze dryer chamber, cooled to -50±2°C at a rate of 1-10°C / min, kept warm for 3-5 hours, the vacuum system is started to reduce the chamber pressure to 8-12 Pa, heated to -25±2°C at a rate of 0.4-0.6°C / min, kept warm for 20-28 hours, and finally heated to 25°C at a rate of 0.1-0.3°C / min, kept warm for 10-14 hours, to obtain a solid hydrogen peroxide block; (3) Under a nitrogen atmosphere, crushing the solid hydrogen peroxide block through an 80-120 mesh sieve to obtain solid hydrogen peroxide particles; In the step (1), the weight ratio of sodium alginate, chitosan, aqueous hydrogen peroxide solution, sodium pyrophosphate and sodium phytate is 1-2:1.4-2.8:40-60:500:0.2-1:0.1-0.

3.

2. The method for preparing solid hydrogen peroxide particles according to claim 1, characterized in that: The viscosity of sodium alginate in step (1) is 1.0-1.2 Pa·s.

3. The method for preparing solid hydrogen peroxide particles according to claim 1, characterized in that: The molecular weight of chitosan in step (1) is 80-120 kDa, and the degree of deacetylation is 95%.

4. The method for preparing solid hydrogen peroxide particles according to claim 1, characterized in that: The concentration of the aqueous hydrogen peroxide solution in step (1) is 30 wt %.

5. The method for preparing solid hydrogen peroxide particles according to claim 1, characterized in that: In the step (2), the liquid layer height of the hydrogen peroxide mixed solution in the freeze-drying dish is 1-2 cm.

6. The method for preparing solid hydrogen peroxide particles according to claim 1, characterized in that: In the step (2), the freeze dryer is precooled to -40±2°C.

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