Gel-like ice and snow material, and preparation method and application thereof

Abstract

The application provides a gel-type ice and snow material and a preparation method and application thereof. The preparation method comprises the following steps: mixing a gelling agent, a thickening agent, a slow-release agent, a cross-linking agent and water, and obtaining a hydrogel through solidification; performing freezing treatment on the hydrogel to obtain an ice gel; and performing heating and drying on the ice gel to form a porous foam layer on the surface of the ice gel, so that the gel-type ice and snow material is obtained. The application realizes surface enhancement of the gel-type ice and snow material, improves recyclability, prolongs cold storage time, and improves cold preservation effect.

Description

Technical Field

[0001] This invention relates to the fields of cold chain logistics and ice and snow cultural and creative industries, and in particular to a gel-like ice and snow material, its preparation method and application. Technical Background

[0002] In the fields of cold chain logistics and ice and snow cultural and creative products, the natural ice and snow materials used suffer from problems such as easy melting, easy deformation, and insufficient cold storage time, which seriously affect their performance. Using gel-based ice and snow materials holds promise for alleviating these issues. However, even with the safety and non-toxicity of the entire preparation process, gel-based ice and snow materials often use highly biocompatible raw materials, resulting in products with poor mechanical properties at room temperature. This makes them prone to damage during use and unable to be recycled. Furthermore, there is a need to extend the cold storage time of gel-based ice and snow materials. Summary of the Invention

[0003] In view of this, the main objective of the present invention is to provide a gel-like ice and snow material, its preparation method and application, in order to at least partially solve at least one of the aforementioned technical problems.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows:

[0005] As one aspect of the present invention, a method for preparing a gel-like ice and snow material is provided, comprising: mixing a gelling agent, a thickener, a slow-release agent, a crosslinking agent and water, and crosslinking the mixture to obtain a hydrogel; freezing the hydrogel to obtain an ice gel; and heating and drying the ice gel to form a porous foam layer on the surface of the ice gel, thereby obtaining a gel-like ice and snow material.

[0006] As another aspect of the present invention, a gel-like ice and snow material prepared by the preparation method described above is provided, wherein the gel-like ice and snow material includes a gel layer and a porous foam layer wrapped around the gel layer.

[0007] As another aspect of the present invention, an application of the gel-like ice and snow material as described above is provided as a solid cold storage agent or ice and snow cultural and creative products.

[0008] Based on the above technical solutions, it can be seen that the gel-like ice and snow materials, their preparation methods, and applications of the present invention have one or more of the following beneficial effects:

[0009] (1) The present invention uses a method of freezing first and then heating and drying the hydrogel. After freezing, the water inside the hydrogel can be frozen, so that the heating and drying process is as limited as possible to the surface of the obtained ice gel. A porous foam layer is covered on the surface of the ice gel to obtain a gel-like ice and snow material.

[0010] (2) In this invention, the internal polymer network will undergo structural relaxation after the ice gel dries and dehydrates. As a result, the formation of the porous foam layer enhances the surface mechanical properties at room temperature. It can maintain its structure during subsequent repeated freezing and thawing, thus improving recyclability.

[0011] (3) The porous foam layer covering the surface of the gel-like ice and snow material prepared by this invention has a heat preservation effect. Therefore, the presence of the porous foam layer will slow down the leakage of cold energy, thereby prolonging the cold storage time and improving the cold preservation effect. Attached Figure Description

[0012] Figure 1 This is a flowchart of the preparation method of gel-like ice and snow materials according to an embodiment of the present invention.

[0013] Figure 2 These are comparative images of the surface morphology of gel-like ice and snow materials of Example 1 and Comparative Example 1 of the present invention, wherein (a) is the gel-like ice and snow material of Comparative Example 1 and (b) is the gel-like ice and snow material of Example 1.

[0014] Figure 3 These are the stress-strain test curves of the gel-like ice and snow materials of Embodiment 1 and Comparative Example 1 of the present invention.

[0015] Figure 4 These are the temperature change curves of the unfoamed portion within the gel-like ice and snow materials of Embodiment 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] In the process of developing this invention, it was discovered that a method of first freezing and then heating and drying the hydrogel allows the internal water of the hydrogel to be frozen to obtain an ice gel. The subsequent heating and drying of the ice gel is then limited to the surface as much as possible, thereby covering the gel surface with a porous foam layer. The formation of the porous foam layer enhances the surface mechanical properties of the gel-like ice and snow materials at room temperature and improves their cold storage capacity. This invention effectively solves the problems of insufficient mechanical properties of gel-like ice and snow materials after melting and the need to extend the cold storage time.

[0018] Specifically, according to some embodiments of the present invention, a method for preparing a gel-like ice and snow material is provided. Figure 1 This is a flowchart of the preparation method of gel-like ice and snow materials according to an embodiment of the present invention, as shown below. Figure 1 As shown, the preparation method includes steps S101 to S103.

[0019] In step S101, the gelling agent, thickener, slow-release agent, crosslinking agent and water are mixed and then cured to obtain a hydrogel;

[0020] In step S102, the hydrogel is frozen to obtain an ice gel;

[0021] In step S103, the ice gel is heated and dried to form a porous foam layer on the surface of the ice gel, thus obtaining a gel-like ice and snow material.

[0022] According to embodiments of the present invention, after the gelling agent, thickener, slow-release agent, and crosslinking agent are mixed and cured, a three-dimensional crosslinked polymer network is formed, with water molecules filling the voids in the polymer network. By freezing the hydrogel, the water inside the hydrogel can be frozen to obtain an ice gel. This allows the subsequent heating and drying process to be limited to the surface of the ice gel as much as possible, so that the water molecules on the surface are replaced by air after drying, forming voids. The resulting gel-like ice and snow material has a porous foam layer covering its surface. Furthermore, the method of freezing first and then heating and drying is low in cost and short in time, greatly improving the practicality of the present invention.

[0023] According to an embodiment of the present invention, in order to form a uniform hydrogel, step S101 specifically includes sub-steps S1011 to S1014.

[0024] In sub-step S1011, the gelling agent and thickener are dissolved in water under heating and stirring to obtain solution A; in sub-step S1012, an aqueous solution of a slow-release agent is added to solution A and stirred until homogeneous to obtain solution B; in sub-step S1013, an aqueous solution of a crosslinking agent is added to solution B and stirred until homogeneous to obtain solution C; in sub-step S1014, solution C is poured into a mold and allowed to stand and solidify to obtain a hydrogel.

[0025] According to an embodiment of the present invention, in sub-step S1011, the heating temperature is 50°C to 98°C, for example, 50°C, 60°C, 70°C, 80°C, 90°C, etc. This is beneficial for the complete dissolution of the gelling agent and thickener in water.

[0026] According to an embodiment of the present invention, in sub-step S1011, in solution A, with water as 100 parts by weight, the gelling agent includes 0.5 to 3 parts by weight of sodium alginate, 0.1 to 2 parts by weight of carrageenan, 0.1 to 1 part by weight of polyacrylate, 0.1 to 2 parts by weight of gelatin and 0.1 to 2 parts by weight of agar; the thickener includes 0.1 to 2 parts by weight of locust bean gum and 0.1 to 2 parts by weight of gellan gum.

[0027] More preferably, with water as 100 parts by weight, the gelling agent includes 1 to 3 parts by weight of sodium alginate, 0.5 to 2 parts by weight of carrageenan, 0.2 to 1 part by weight of polyacrylate, 0.5 to 2 parts by weight of gelatin and 0.5 to 2 parts by weight of agar; the thickener includes 0.2 to 1.5 parts by weight of locust bean gum and 0.2 to 2 parts by weight of gellan gum.

[0028] Most preferably, with water as 100 parts by weight, the gelling agent includes 1.5 to 2 parts by weight of sodium alginate, 1 to 2 parts by weight of carrageenan, 0.5 to 1 part by weight of polyacrylate, 1 to 2 parts by weight of gelatin and 0.5 to 2 parts by weight of agar; the thickener includes 0.5 to 1 part by weight of locust bean gum and 0.5 to 1.5 parts by weight of gellan gum.

[0029] According to an embodiment of the present invention, in sub-step S1012, in solution B, the aqueous solution of the slow-release agent accounts for 2% to 20% of the volume fraction of solution A, and the mass fraction of the aqueous solution of the slow-release agent is 0.005% to 2%, more preferably 0.3% to 1.5%, and most preferably 0.7% to 1.2%; wherein the slow-release agent preferably includes sodium pyrophosphate.

[0030] According to an embodiment of the present invention, in sub-step S1013, in solution C, the aqueous solution of the crosslinking agent accounts for 2% to 30% of the volume of solution B, wherein the mass fraction of the aqueous solution of the crosslinking agent is 0.05% to 0.4%, more preferably 0.1% to 0.3%; wherein the crosslinking agent preferably includes a calcium salt, more preferably selected from one or more of calcium sulfate, calcium chloride, calcium bromide, calcium iodide, calcium nitrate, calcium formate, and calcium acetate.

[0031] According to embodiments of the present invention, based on the above-mentioned highly biocompatible hydrogel composition, a uniform hydrogel or ice gel can be formed while ensuring the safety and non-toxicity of the preparation process, and at the same time, it is beneficial to stably form a porous foam layer on the gel surface.

[0032] According to an embodiment of the present invention, in order to better freeze the hydrogel, step S102 specifically includes: freezing the hydrogel at -40 to -2°C for 0.5 to 24 hours, so that the hydrogel is completely frozen and solidified. For example, it can be frozen at -30°C, -20°C, -10°C, or -5°C for 0.5 hours, 2 hours, 4 hours, 8 hours, 12 hours, or 16 hours, etc.

[0033] According to an embodiment of the present invention, in order to better heat-dry the ice gel, step S103 specifically includes: drying the ice gel at 40-200°C for 10-120 minutes. For example, it can be dried at 50°C, 80°C, 100°C, 120°C or 160°C for 20 minutes, 40 minutes, 60 minutes, 80 minutes or 100 minutes, etc.

[0034] According to an embodiment of the present invention, the above-described freezing and heating drying conditions facilitate the formation of a porous foam layer.

[0035] According to some embodiments of the present invention, a gel-like ice and snow material prepared by the preparation method described above is also provided, wherein the gel-like ice and snow material includes a gel layer and a porous foam layer covering the gel layer.

[0036] According to an embodiment of the present invention, the porous foam layer covering the gel layer achieves surface reinforcement of the gel-like ice and snow material, maintains its structure during repeated freezing and thawing, and improves recyclability; at the same time, the porous foam layer provides good heat preservation, prolongs the cold storage time, and improves the cold preservation effect.

[0037] According to an embodiment of the present invention, the thickness of the porous foam layer is 3-5 mm. A suitable porous foam layer thickness is beneficial for surface reinforcement and improves cold storage performance.

[0038] According to some embodiments of the present invention, the application of the gel-like ice and snow material as described above as a solid cold storage agent or ice and snow cultural and creative products is also provided.

[0039] The following detailed description, in conjunction with specific embodiments and accompanying drawings, further illustrates the gel-based ice and snow materials of the present invention, their preparation methods, and applications. It should be noted that the specific embodiments described below are merely illustrative examples, and the scope of protection of the present invention is not limited thereto. All pharmaceuticals or reagents used in the following embodiments are commercially available or prepared using known methods.

[0040] Example 1:

[0041] Step 1: Weigh 2 parts by weight of sodium alginate, 1.5 parts by weight of carrageenan, 1 part by weight of polyacrylate, 1.5 parts by weight of gelatin, 1 part by weight of locust bean gum, 1 part by weight of gellan gum, and 1.5 parts by weight of agar. Slowly add them to hot water at 50-98°C and stir continuously until completely dissolved to obtain solution A.

[0042] Step 2: Add sodium pyrophosphate slow-release solution with a volume fraction of 10% and a mass fraction of 0.1% to solution A, stir well to obtain solution B;

[0043] Step 3: Add a 15% (v / v) calcium salt crosslinking agent solution to solution B. The mass fraction of the crosslinking agent aqueous solution is 0.2%. Stir well to obtain solution C.

[0044] Step 4: Pour solution C into the mold and let it stand to solidify for 12 hours;

[0045] Step 5: Place the demolded sample in a -20℃ environment and freeze for 12 hours until completely frozen;

[0046] Step 6: Place the frozen sample in an environment of 150°C to dry for 60 minutes to obtain the final ice and snow material covered with a porous foam layer.

[0047] Comparative Example 1

[0048] Similar to the operation in Example 1, the only difference is the absence of step 6, which uses the frozen sample from step 5 as a gel-like ice and snow material.

[0049] Performance testing:

[0050] 1. The surface morphology of the gel-like ice and snow materials in Example 1 and Comparative Example 1 were observed respectively, such as... Figure 2 As shown, compared to Comparative Example 1, the method of freezing followed by heating and drying in Example 1 can form a porous foam layer with a thickness of about 3 to 5 mm on the surface of the gel layer.

[0051] 2. Stress-strain tests were conducted on the gel-like ice and snow materials of Example 1 and Comparative Example 1 at room temperature using a tensile testing machine, such as... Figure 3 As shown, compared to Comparative Example 1, the presence of a porous foam layer in Example 1 improves the mechanical properties of the gel-like ice and snow material.

[0052] 3. The temperature change of the unfoamed portion within the gel-based ice and snow materials of Example 1 and Comparative Example 1 was measured at room temperature. Figure 4 As shown, it was found that compared with Comparative Example 1, the presence of a porous foam layer in Example 1 extended the cold preservation time and improved the cold storage capacity.

[0053] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a gel-like ice and snow material, comprising: A hydrogel is obtained by mixing a gelling agent, a thickener, a slow-release agent, a crosslinking agent, and water, and then solidifying the mixture, wherein water accounts for 100 parts by weight. The gelling agent includes 0.5 to 3 parts by weight of sodium alginate, 0.1 to 2 parts by weight of carrageenan, 0.1 to 1 part by weight of polyacrylate, 0.1 to 2 parts by weight of gelatin, and 0.1 to 2 parts by weight of agar. The hydrogel was frozen to obtain an ice gel; The ice gel is heated and dried to form a porous foam layer on the surface of the ice gel, thus obtaining the gel-like ice and snow material.

2. The preparation method according to claim 1, wherein, The cryotreatment of the hydrogel includes: The hydrogel is frozen at -40 to 2°C for 0.5 to 24 hours to completely freeze and solidify it.

3. The preparation method according to claim 2, wherein, Heating and drying the ice gel includes: The ice gel was dried at 40-200°C for 10-120 minutes.

4. The preparation method according to claim 1, wherein, Hydrogels are obtained by mixing gelling agents, thickeners, slow-release agents, crosslinking agents, and water, followed by curing. The gelling agent and the thickener are dissolved in water under heating and stirring to obtain solution A; An aqueous solution of the sustained-release agent is added to solution A, and the mixture is stirred until homogeneous to obtain solution B; An aqueous solution of the crosslinking agent is added to solution B, and the mixture is stirred until homogeneous to obtain solution C; The solution C is poured into a mold and allowed to stand and solidify to obtain the hydrogel.

5. The preparation method according to claim 4, wherein, In solution A, with water as 100 parts by weight, the thickener includes 0.1 to 2 parts by weight of locust bean gum and 0.1 to 2 parts by weight of gellan gum.

6. The preparation method according to claim 4, wherein, In solution B, the aqueous solution of the sustained-release agent accounts for 2% to 20% of the volume fraction of solution A, and the aqueous solution of the sustained-release agent has a mass fraction of 0.005% to 2%.

7. The preparation method according to claim 4 or 6, wherein, The sustained-release agent includes sodium pyrophosphate.

8. The preparation method according to claim 4, wherein, In solution C, the aqueous solution of the crosslinking agent accounts for 2% to 30% of the volume of solution B, and the mass fraction of the aqueous solution of the crosslinking agent is 0.05% to 0.4%.

9. The preparation method according to claim 4 or 8, wherein, The crosslinking agent includes calcium salts.

10. The preparation method according to claim 4 or 8, wherein, The crosslinking agent is selected from one or more of calcium sulfate, calcium chloride, calcium bromide, calcium iodide, calcium nitrate, calcium formate, and calcium acetate.

11. A gel-like ice and snow material prepared by the preparation method according to any one of claims 1 to 10, wherein, The gel-based ice and snow material includes a gel layer and a porous foam layer covering the gel layer.

12. The gel-based ice and snow material according to claim 11, wherein, The thickness of the porous foam layer is 3~5 nm.

13. An application of the gel-like ice and snow material as described in claim 11 or 12 as a solid cold storage agent or ice and snow cultural and creative products.

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