-6 DEG C antibacterial phase change cold storage agent and preparation method thereof

Abstract

The invention relates to a-6 DEG C antibacterial phase change cold storage agent and a preparation method thereof. The crystallization temperature of the-6 DEG C antibacterial phase change cold storage agent ranges from-7 DEG C to-5 DEG C. The antibacterial phase change cold storage agent obtained according to the invention can be used in the fields of refrigerated transportation, fresh-keeping transportation and the like. The invention relates to a-6 DEG C antibacterial phase change cold storage agent, which is characterized by being mainly prepared from the following raw materials in percentage by mass: 1.6 to 3.2 percent of bacterial cellulose, 15 to 18 percent of polyvinyl alcohol, 1.6 to 1.8 percent of zinc acetate, 0.3 to 0.5 percent of sodium hydroxide solution and the balance of deionized water. The antibacterial phase change cold storage agent obtained by the method has the characteristics of good antibacterial effect and leakage prevention.

Description

Technical Field

[0001] The present invention relates to a -6°C antibacterial phase-change cold storage agent and a preparation method thereof, wherein the crystallization temperature is between -7°C and -5°C. The antibacterial phase-change cold storage agent obtained according to the present invention can be used in the fields of refrigerated transportation, fresh-keeping transportation, etc. Background Art

[0002] Phase change refrigerants refer to a class of substances that absorb or release energy during the phase change process. They can store the energy people need in a certain form under specific conditions, and can release and utilize it under specific conditions required, thereby meeting the needs of different application scenarios. At the same time, with the development of the fresh food industry and the express delivery industry, phase change refrigerants are widely used in temperature-controlled packaging and cold chain logistics. However, since solid-liquid phase change materials produce liquid when they undergo phase change, there is a risk of leakage. Therefore, how to effectively solve the problem of leakage while ensuring the efficient use of phase change refrigerants has become the focus of research and improvement in related fields. Summary of the invention

[0003] The object of the present invention is to provide a -6°C antibacterial phase-change refrigerant and a preparation method thereof. The antibacterial phase-change refrigerant obtained by the method has the characteristics of good antibacterial effect and anti-leakage.

[0004] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is: a -6°C antibacterial phase change refrigerant, characterized in that it is mainly prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water, and the mass percentage of each raw material is: bacterial cellulose 1.6-3.2%, polyvinyl alcohol 15-18%, zinc acetate 1.6-1.8%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.3-0.5%, and the rest is deionized water.

[0005] Preferably, the crystallization temperature of the -6°C antibacterial phase-change refrigerant is -7°C to -5°C.

[0006] Preferably, the -6°C antibacterial phase change refrigerant has a latent heat of fusion of 162.3 J / g to 210.7 J / g.

[0007] Preferably, the -6°C antibacterial phase change refrigerant has a latent heat of fusion of 210.7 J / g.

[0008] The method for preparing the -6°C antibacterial phase-change refrigerant is characterized by comprising the following steps:

[0009] 1) According to the mass percentage of each raw material: bacterial cellulose 1.6-3.2%, polyvinyl alcohol 15-18%, zinc acetate 1.6-1.8%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.3-0.5%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for standby use;

[0010] 2) Add polyvinyl alcohol to the deionized water in step 1), and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence, and stir evenly;

[0011] 3) adjusting the pH to 10 with NaOH solution, stirring evenly, and generating zinc oxide by hydrothermal reaction at 100° C. for 10 h; cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0012] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0013] Preferably, in step 2) water bath heating, the water bath temperature is 98° C. and the heating time is 30 minutes.

[0014] Preferably, the freeze-thaw in step 4) is performed by placing the product in a -20°C refrigerator for 5 hours, taking it out, and placing it in a -20°C refrigerator again for freezing after it is completely thawed at room temperature, and repeating this process 3 times.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The -6°C antibacterial phase-change refrigerant of the present invention contains zinc oxide (zinc oxide generated in step 3)), which has an antibacterial effect.

[0017] 2. The -6°C antibacterial phase-change refrigerant of the present invention is in a gel state and is used in the fields of refrigerated transportation, fresh-keeping transportation, etc., and has a leakage-proof effect.

[0018] 3. The -6°C antibacterial phase-change refrigerant of the present invention has a crystallization temperature of -7°C to -5°C and a phase-change latent heat of up to 210.7 J / g.

[0019] 4. The -6°C antibacterial phase-change refrigerant of the present invention is a combination of organic and inorganic substances. As a refrigerant, it has a low degree of supercooling and can effectively solve the problem of low refrigeration efficiency.

[0020] 5. The -6°C antibacterial phase-change refrigerant of the present invention contains a metal composite material and has the characteristics of fast heat conduction and stable system.

[0021] 6. The -6°C antibacterial phase-change refrigerant of the present invention can store cold repeatedly and has a long service life.

[0022] 7. The -6°C antibacterial phase-change coolant of the present invention is a refrigerant that can meet the needs of keeping meat and seafood fresh; it can be used in refrigerated storage and transportation, which can greatly reduce transportation costs and ensure the quality of transported products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a digital image of the antibacterial phase change refrigerant of Example 1 of the present invention from a top view.

[0024] Figure 2 This is a digital image of the side view of the antibacterial phase change refrigerant of Example 1 of the present invention.

[0025] Figure 3 This is a DSC thermal image of the phase change process of the antibacterial phase change refrigerant of Example 1 of the present invention.

[0026] Figure 4 This is a DSC thermal image of the antibacterial phase-change coolant of Example 1 of the present invention during the heating process before and after 100 cycles. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. 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. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer.

[0028] The raw materials used in the embodiments of the present invention are all commercially available.

[0029] The -6°C antibacterial phase-change refrigerant provided by the present invention has its crystallization temperature measured by a step cooling curve method, and its melting latent heat measured by a DSC differential thermal method.

[0030] Example 1

[0031] The invention discloses a -6°C antibacterial phase-change refrigerant, which is prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the mass percentage of each raw material is as follows: 3.2% of bacterial cellulose, 15.8% of polyvinyl alcohol, 1.8% of zinc acetate, 0.3% of sodium hydroxide solution (the concentration of the sodium hydroxide solution is 2 mol / L), and the rest is deionized water.

[0032] The preparation method of the above-mentioned -6°C antibacterial phase-change refrigerant comprises the following steps:

[0033] 1) According to the mass percentage of each raw material: bacterial cellulose 3.2%, polyvinyl alcohol 15.8%, zinc acetate 1.8%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.3%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for standby use;

[0034] 2) Add polyvinyl alcohol to the deionized water in step 1) and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence and stir evenly; the water bath heating is performed at a water bath temperature of 98° C. for 30 minutes;

[0035] 3) adjusting the pH to 10 with NaOH solution, stirring evenly, generating zinc oxide by hydrothermal reaction at 100° C. for 10 h, cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0036] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0037] In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

[0038] The -6℃ antibacterial phase change refrigerant has a crystallization temperature of -6.5℃ and a melting latent heat of 162.3J / g according to the step cooling curve method. The -6℃ antibacterial phase change refrigerant is in a gel state and is used in refrigerated transportation, fresh-keeping transportation and other fields, and has a leakage prevention effect.

[0039] Example 2

[0040] The invention discloses a -6°C antibacterial phase-change refrigerant, which is prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the mass percentage of each raw material is: 2.8% of bacterial cellulose, 16.2% of polyvinyl alcohol, 1.8% of zinc acetate, 0.3% of sodium hydroxide solution and the rest is deionized water.

[0041] The preparation method of the above-mentioned -6°C antibacterial phase-change refrigerant comprises the following steps:

[0042] 1) According to the mass percentage of each raw material: bacterial cellulose 2.8%, polyvinyl alcohol 16.2%, zinc acetate 1.8%, sodium hydroxide solution 0.3%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for use;

[0043] 2) Add polyvinyl alcohol to the deionized water in step 1) and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence and stir evenly; the water bath heating is performed at a water bath temperature of 98° C. for 30 minutes;

[0044] 3) adjusting the pH to 10 with NaOH solution, generating zinc oxide by hydrothermal reaction at 100° C. for 10 h, cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0045] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0046] In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

[0047] The -6℃ antibacterial phase change refrigerant has a crystallization temperature of -5.6℃ and a melting latent heat of 190.1J / g according to the step cooling curve method. The -6℃ antibacterial phase change refrigerant is in a gel state and is used in refrigerated transportation, fresh-keeping transportation and other fields, and has a leakage prevention effect.

[0048] Example 3

[0049] The invention discloses a -6°C antibacterial phase-change refrigerant, which is prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the weight percentage of each raw material is as follows: 2.4% of bacterial cellulose, 16.6% of polyvinyl alcohol, 1.8% of zinc acetate, 0.3% of sodium hydroxide solution (the concentration of the sodium hydroxide solution is 2 mol / L), and the rest is deionized water.

[0050] The preparation method of the above-mentioned -6°C antibacterial phase-change refrigerant comprises the following steps:

[0051] 1) According to the mass percentage of each raw material: bacterial cellulose 2.4%, polyvinyl alcohol 16.6%, zinc acetate 1.8%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.3%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for standby use;

[0052] 2) Add polyvinyl alcohol to the deionized water in step 1) and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence and stir evenly; the water bath heating is performed at a water bath temperature of 98° C. for 30 minutes;

[0053] 3) adjusting the pH to 10 with NaOH solution, generating zinc oxide by hydrothermal reaction at 100° C. for 10 h; cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0054] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0055] In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

[0056] The -6℃ antibacterial phase change refrigerant has a crystallization temperature of -5.4℃ and a melting latent heat of 210.7J / g according to the step cooling curve method. The -6℃ antibacterial phase change refrigerant is in a gel state and is used in refrigerated transportation, fresh-keeping transportation and other fields, and has a leakage prevention effect.

[0057] The performance parameters such as phase change temperature, phase change latent heat and inhibition zone of the composite coolant prepared in Examples 1-3 were measured using a differential scanning calorimeter. The results are shown in Table 1.

[0058] Table 1

[0059]

[0060] It can be seen from Table 1 that the antibacterial phase change refrigerant prepared in Examples 1-3 of the present invention has a good phase change latent heat and good antibacterial property.

[0061] Example 4

[0062] The invention discloses a -6°C antibacterial phase-change refrigerant, which is prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the weight percentage of each raw material is as follows: 1.6% of bacterial cellulose, 15% of polyvinyl alcohol, 1.6% of zinc acetate, 0.5% of sodium hydroxide solution (the concentration of the sodium hydroxide solution is 2 mol / L), and the rest is deionized water.

[0063] The preparation method of the above-mentioned -6°C antibacterial phase-change refrigerant comprises the following steps:

[0064] 1) According to the mass percentage of each raw material: bacterial cellulose 1.6%, polyvinyl alcohol 15%, zinc acetate 1.6%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.5%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for standby use;

[0065] 2) Add polyvinyl alcohol to the deionized water in step 1) and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence and stir evenly; the water bath heating is performed at a water bath temperature of 98° C. for 30 minutes;

[0066] 3) adjusting the pH to 10 with NaOH solution, stirring evenly, and generating zinc oxide by hydrothermal reaction at 100° C. for 10 h; cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0067] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0068] In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

[0069] The -6℃ antibacterial phase-change refrigerant is in gel state and is used in the fields of refrigerated transportation, fresh-keeping transportation, etc., and has a leakage-proof effect.

[0070] Example 5

[0071] The invention discloses a -6°C antibacterial phase-change refrigerant, which is prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the mass percentage of each raw material is as follows: 1.6% of bacterial cellulose, 18% of polyvinyl alcohol, 1.6% of zinc acetate, 0.5% of sodium hydroxide solution (the concentration of the sodium hydroxide solution is 2 mol / L), and the rest is deionized water.

[0072] The preparation method of the above-mentioned -6°C antibacterial phase-change refrigerant comprises the following steps:

[0073] 1) According to the mass percentage of each raw material: bacterial cellulose 1.6%, polyvinyl alcohol 18%, zinc acetate 1.6%, sodium hydroxide solution (the concentration of sodium hydroxide solution is 2 mol / L) 0.5%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for standby use;

[0074] 2) Add polyvinyl alcohol to the deionized water in step 1) and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence and stir evenly; the water bath heating is performed at a water bath temperature of 98° C. for 30 minutes;

[0075] 3) adjusting the pH to 10 with NaOH solution, stirring evenly, and generating zinc oxide by hydrothermal reaction at 100° C. for 10 h; cooling to room temperature, and adding the sodium hydroxide solution described in step 1);

[0076] 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

[0077] In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

[0078] The -6℃ antibacterial phase-change refrigerant is in gel state and is used in the fields of refrigerated transportation, fresh-keeping transportation, etc., and has a leakage-proof effect.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. Therefore, all changes that are equivalent to the characteristic raw materials, characteristic steps and formulas within the scope described in the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A -6℃ antibacterial phase change refrigerant, characterized in that The invention is mainly prepared from bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution and deionized water, wherein the mass percentage of each raw material is as follows: 1.6-3.2% of bacterial cellulose, 15-18% of polyvinyl alcohol, 1.6-1.8% of zinc acetate, 0.3-0.5% of sodium hydroxide solution and the rest is deionized water.

2. The -6°C antibacterial phase change refrigerant according to claim 1, characterized in that: The concentration of sodium hydroxide solution is 2 mol / L.

3. The -6°C antibacterial phase change refrigerant according to claim 1, characterized in that: The crystallization temperature of the -6°C antibacterial phase-change refrigerant is -7°C to -5°C.

4. The -6°C antibacterial phase change refrigerant according to claim 1, characterized in that: The melting latent heat of the -6°C antibacterial phase-change refrigerant is 162.3 J / g to 210.7 J / g.

5. The -6°C antibacterial phase-change refrigerant according to claim 4, characterized in that: The melting latent heat of the -6°C antibacterial phase-change refrigerant is 210.7 J / g.

6. The method for preparing a -6°C antibacterial phase-change refrigerant according to claim 1, characterized in that The steps include: 1) According to the mass percentage of each raw material: bacterial cellulose 1.6-3.2%, polyvinyl alcohol 15-18%, zinc acetate 1.6-1.8%, sodium hydroxide solution 0.3-0.5%, and the rest is deionized water, bacterial cellulose, polyvinyl alcohol, zinc acetate, sodium hydroxide solution, and deionized water are selected for use; 2) Add polyvinyl alcohol to the deionized water in step 1), and heat in a water bath to dissolve the polyvinyl alcohol; after cooling to room temperature, add zinc acetate and bacterial cellulose in sequence, and stir evenly; 3) Adjust the pH to 10 with NaOH solution, stir evenly, and generate zinc oxide by hydrothermal reaction at 100°C for 10 hours; Cool to room temperature, and add the sodium hydroxide solution described in step 1); 4) freeze-thaw cycle 3 times, wash with deionized water to neutral pH, and obtain -6°C antibacterial phase change coolant.

7. The method for preparing a -6°C antibacterial phase-change refrigerant according to claim 6, characterized in that: The concentration of the sodium hydroxide solution in step 1) is 2 mol / L.

8. The method for preparing a -6°C antibacterial phase-change refrigerant according to claim 6, characterized in that: The step 2) of water bath heating is performed at a water bath temperature of 98° C. for 30 minutes.

9. The method for preparing a -6°C antibacterial phase-change refrigerant according to claim 6, characterized in that: In the step 4), the freeze-thaw step is to place the sample in a -20°C refrigerator for 5 hours, take it out, and continue to place it in a -20°C refrigerator for freezing after it is completely thawed at room temperature, and repeat this process 3 times.

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