A method for preparing high-strength sodium alginate gel

Abstract

The invention relates to the technical field of sodium alginate gel preparation, and particularly to a method for preparing high-strength sodium alginate gel. The method comprises the following steps: placing the sodium alginate gel in a 50-200 millimole per liter calcium chloride solution for full immersion, fully washing the sodium alginate gel with deionized water, soaking the sodium alginate gel in a 100-400 millimole per liter metal salt solution, allowing the solution to stand for 24-72 hours, and fully washing the sodium alginate gel with deionized water to obtain the high-strength sodium alginate gel. The high-strength sodium alginate gel prepared through the above steps has the characteristics of high strength, high elastic modulus, and is not easily decomposed in water, thereby achieving the goal of increasing the strength and elastic modulus of the hydrogel.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium alginate gel, in particular to a method for preparing high-strength sodium alginate gel. Background Art

[0002] Hydrogels are materials that use water as a dispersion medium, typically forming a three-dimensional network structure. They can absorb large amounts of water, with water content reaching up to 99%. Hydrogels exhibit excellent flexibility, the ability to maintain a defined shape, strong plasticity, and good biocompatibility. Currently, hydrogel production involves adding a calcium salt solution to a sodium alginate solution. The calcium ions replace the sodium ions, forming a hydrogel with a three-dimensional network structure.

[0003] However, the sodium alginate gel produced by the above steps has poor strength, low elastic modulus, and is easily decomposed in water. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing high-strength sodium alginate gel, aiming to solve the technical problems of poor strength, low elastic modulus and easy decomposition in water of sodium alginate gel in the prior art.

[0005] To achieve the above object, the present invention adopts a method for preparing a high-strength sodium alginate gel, comprising the following steps:

[0006] Preparation of sodium alginate gel;

[0007] The sodium alginate gel is placed in a 50-200 mmol / L calcium chloride solution and fully soaked;

[0008] The sodium alginate gel is thoroughly washed with deionized water;

[0009] Soaking the sodium alginate gel in a 100-400 mmol / L metal salt solution and allowing it to stand for 24-72 hours;

[0010] The sodium alginate gel is fully washed with deionized water to obtain a high-strength sodium alginate gel.

[0011] Wherein, in the step of placing the sodium alginate gel in a 50-200 mmol / L calcium chloride solution and fully soaking it:

[0012] The soaking time is 24 to 72 hours.

[0013] Wherein, in the step of immersing the sodium alginate gel in a 100-400 mmol / L metal salt solution and allowing it to stand for 24-72 hours:

[0014] The metal salt solution is one of barium chloride, strontium chloride, aluminum chloride or ferric chloride.

[0015] Wherein, in the step of preparing sodium alginate gel, the preparation process is:

[0016] Add 50-500 g of deionized water to 0.5-5 g of sodium alginate powder, heat and dissolve under magnetic stirring until clear and transparent to obtain a mixed solution;

[0017] 0.05-0.4 g of calcium sulfate and 0.5-2 ml of acetic acid were sequentially added to the mixed solution, and magnetic stirring was continued at 5-50 degrees to fully mix to obtain a mixture;

[0018] Pour the mixture into a mold, place it in an environment with a temperature of 0 to 10 degrees, and let it stand to form a gel;

[0019] The gel was taken out and placed for natural drying and dehydration to obtain sodium alginate gel.

[0020] Wherein, in the step of pouring the mixture into a mold and allowing it to stand to form a gel:

[0021] The standing temperature is 0 to 10 degrees, and the standing time is 12 to 36 hours.

[0022] Wherein, in the step of taking out the gel and placing it for natural drying and dehydration to obtain the sodium alginate gel:

[0023] The storage temperature is 15 to 30 degrees, the air humidity is 10 to 30%, and the storage time is 48 to 96 hours.

[0024] The present invention provides a method for preparing a high-strength sodium alginate gel. The method comprises the following steps: preparing the sodium alginate gel, placing the sodium alginate gel in a 50-200 millimole per liter calcium chloride solution, fully soaking the sodium alginate gel, fully washing the sodium alginate gel with deionized water, soaking the sodium alginate gel in a 100-400 millimole per liter metal salt solution, standing the solution for 24-72 hours, and fully washing the sodium alginate gel with deionized water to obtain the high-strength sodium alginate gel. The prepared high-strength sodium alginate gel has the characteristics of high strength, high elastic modulus, and is not easily decomposed in water. By adopting the methods of slow crosslinking, rehydration and recrosslinking, and ion exchange and recrosslinking, the sodium alginate gel is fully combined with metal ions, thereby increasing the strength and elastic modulus of the hydrogel and making it not easily decomposed in water. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a step flow chart of Example 1 of the present invention.

[0027] Figure 2 It is a step flow chart of Example 2 of the present invention.

[0028] Figure 3 This is a step flow chart of Example 3 of the present invention.

[0029] Figure 4 This is a data chart of the elastic modulus of the sodium alginate gel of the present invention after being cross-linked with different metal ions.

[0030] Figure 5 This is a data chart showing the tensile strength of the sodium alginate gel of the present invention after being cross-linked with different metal ions.

[0031] Figure 6 The graph is a data chart of cell growth absorbance of the sodium alginate gel of the present invention after being cross-linked with different metal ions and co-cultured with human fibroblasts. DETAILED DESCRIPTION

[0032] Example 1, please refer to Figure 1 ,in Figure 1 1 is a flow chart of the steps of Example 1. The present invention provides a method for preparing high-strength sodium alginate gel, comprising the following steps:

[0033] S1: Add 500 g of deionized water to 5 g of sodium alginate powder, and heat with magnetic stirring to dissolve until clear and transparent to obtain a mixed solution;

[0034] S2: adding 0.4 g of calcium sulfate and 2 ml of acetic acid to the mixed solution in sequence, and continuing to magnetically stir at 50 degrees to mix thoroughly to obtain a mixture;

[0035] S3: pouring the mixture into a mold, placing it in an environment with a temperature of 10 degrees, and letting it stand for 36 hours, using a slow cross-linking mode to start curing from the inside of the mixture to form a gel;

[0036] S4: taking out the gel and placing it in an environment with a temperature of 30 degrees and an air humidity of 30% for 96 hours to naturally dry and dehydrate the gel, so that the gel forms a porous structure, thereby obtaining a sodium alginate gel;

[0037] S5: placing the sodium alginate gel in a 200 mmol / L calcium chloride solution and fully soaking it for 72 hours, so that calcium ions enter the interior of the sodium alginate gel through hydration and swelling, completing cross-linking and curing, and increasing the strength of the sodium alginate gel;

[0038] S6: using deionized water to fully wash the sodium alginate gel;

[0039] S7: Soaking the sodium alginate gel in a 400 mmol / L metal salt solution and allowing it to stand for 72 hours, so that the metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel;

[0040] S8: The sodium alginate gel is thoroughly washed with deionized water to obtain a high-strength sodium alginate gel.

[0041] In this embodiment, first, 500 grams of deionized water are added to 5 grams of sodium alginate powder, and the mixture is heated and dissolved by magnetic stirring until it is clear and transparent to obtain a mixed solution. Then, 0.4 grams of calcium sulfate and 2 milliliters of acetic acid are added to the mixed solution in sequence, and magnetic stirring is continued at 50 degrees to fully mix to obtain a mixture. The mixture is poured into a mold, placed in an environment with a temperature of 10 degrees, and allowed to stand for 36 hours. A slow cross-linking mode is adopted to solidify from the inside of the mixture to form a gel. The gel is then taken out and placed in an environment with a temperature of 30 degrees and an air humidity of 30%. It is placed for 96 hours to dry and dehydrate naturally. The gel forms a porous structure to obtain a sodium alginate gel. The sodium alginate gel is placed in a 200 millimole per liter calcium chloride solution and fully soaked for 72 hours. The calcium ions swell by hydration. The method uses a metal ion to enter the interior of the sodium alginate gel to complete cross-linking and curing, thereby increasing the strength of the sodium alginate gel. The sodium alginate gel is then fully washed with deionized water. The sodium alginate gel is then immersed in a 400 millimole per liter metal salt solution and allowed to stand for 72 hours. The metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel. Finally, the sodium alginate gel is fully washed with deionized water to obtain a high-strength sodium alginate gel. The prepared high-strength sodium alginate gel has the characteristics of high strength, high elastic modulus, and is not easy to decompose in water. By adopting the method of slow cross-linking, rehydration and re-cross-linking, and ion exchange and re-cross-linking, the sodium alginate gel is fully combined with the metal ions, thereby increasing the strength and elastic modulus of the hydrogel and making it not easy to decompose in water.

[0042] Example 2, please refer to Figure 2 ,in Figure 2 2 is a flow chart of the steps of Example 2. The present invention provides a method for preparing high-strength sodium alginate gel, comprising the following steps:

[0043] S1: Add 300 g of deionized water to 3 g of sodium alginate powder, and heat with magnetic stirring to dissolve until clear and transparent to obtain a mixed solution;

[0044] S2: 0.25 g of calcium sulfate and 1.8 ml of acetic acid were added to the mixed solution in sequence, and the mixture was thoroughly mixed by continuing magnetic stirring at 30°C to obtain a mixture;

[0045] S3: pouring the mixture into a mold, placing it in an environment with a temperature of 5 degrees, and letting it stand for 24 hours. Using a slow cross-linking mode, the mixture begins to solidify from the inside to form a gel;

[0046] S4: taking out the gel and placing it in an environment with a temperature of 23.5 degrees and an air humidity of 20% for 72 hours to naturally dry and dehydrate the gel, so that the gel forms a porous structure, thereby obtaining a sodium alginate gel;

[0047] S5: placing the sodium alginate gel in a 150 mmol / L calcium chloride solution and fully soaking it for 48 hours, so that calcium ions enter the interior of the sodium alginate gel through hydration and swelling, completing cross-linking and curing, thereby increasing the strength of the sodium alginate gel;

[0048] S6: using deionized water to fully wash the sodium alginate gel;

[0049] S7: Soaking the sodium alginate gel in a 250 mmol / L metal salt solution and allowing it to stand for 48 hours, so that the metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel;

[0050] S8: The sodium alginate gel is thoroughly washed with deionized water to obtain a high-strength sodium alginate gel.

[0051] In this embodiment, first, 300 grams of deionized water are added to 3 grams of sodium alginate powder, and the mixture is heated and dissolved by magnetic stirring until it is clear and transparent to obtain a mixed solution. Then, 0.25 grams of calcium sulfate and 1.8 milliliters of acetic acid are added to the mixed solution in sequence, and magnetic stirring is continued at 30 degrees to fully mix to obtain a mixture. The mixture is poured into a mold, placed in an environment at a temperature of 5 degrees, and allowed to stand for 24 hours. A slow cross-linking mode is adopted to solidify from the inside of the mixture to form a gel. The gel is then taken out and placed in an environment at a temperature of 23.5 degrees and an air humidity of 20%. It is placed for 72 hours to dry and dehydrate naturally. The gel forms a porous structure to obtain a sodium alginate gel. The sodium alginate gel is placed in a 150 millimole per liter calcium chloride solution and fully soaked for 48 hours. The calcium ions are dissolved by hydration. The sodium alginate gel is expanded by the action of the metal salt, and the cross-linking and curing are completed, thereby increasing the strength of the sodium alginate gel. The sodium alginate gel is then fully washed with deionized water, and then immersed in a 250 mmol / L metal salt solution and allowed to stand for 48 hours. The metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel. Finally, the sodium alginate gel is fully washed with deionized water to obtain a high-strength sodium alginate gel. The prepared high-strength sodium alginate gel has the characteristics of high strength, high elastic modulus, and is not easy to decompose in water. By adopting the method of slow cross-linking, rehydration and re-cross-linking, and ion exchange and re-cross-linking, the sodium alginate gel is fully combined with the metal ions, thereby increasing the strength and elastic modulus of the hydrogel and making it not easy to decompose in water.

[0052] Example 3, please refer to Figure 3 ,in Figure 3 3 is a flow chart of the steps of Example 3. The present invention provides a method for preparing high-strength sodium alginate gel, comprising the following steps:

[0053] S1: Add 50 g of deionized water to 0.5 g of sodium alginate powder, and heat and dissolve under magnetic stirring until clear and transparent to obtain a mixed solution;

[0054] S2: adding 0.05 g of calcium sulfate and 0.5 ml of acetic acid to the mixed solution in sequence, and continuing to stir the mixture under magnetic stirring at 5 degrees to obtain a mixture;

[0055] S3: pouring the mixture into a mold, placing it in an environment with a temperature of 0 degrees, and letting it stand for 12 hours. Using a slow cross-linking mode, the mixture begins to solidify from the inside to form a gel;

[0056] S4: taking out the gel and placing it in an environment with a temperature of 15 degrees and an air humidity of 10% for 48 hours to naturally dry and dehydrate the gel, so that the gel forms a porous structure, thereby obtaining a sodium alginate gel;

[0057] S5: placing the sodium alginate gel in a 50 mmol / L calcium chloride solution and fully soaking it for 24 to 72 hours, so that calcium ions enter the interior of the sodium alginate gel through hydration and swelling, completing cross-linking and curing, thereby increasing the strength of the sodium alginate gel;

[0058] S6: using deionized water to fully wash the sodium alginate gel;

[0059] S7: Soaking the sodium alginate gel in a 100 mmol / L metal salt solution and allowing it to stand for 24 hours, so that the metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel;

[0060] S8: The sodium alginate gel is thoroughly washed with deionized water to obtain a high-strength sodium alginate gel.

[0061] In this embodiment, first, 50 grams of deionized water are added to 0.5 grams of sodium alginate powder, and the mixture is heated and dissolved by magnetic stirring until it is clear and transparent to obtain a mixed solution. Then, 0.05 grams of calcium sulfate and 0.5 milliliters of acetic acid are added to the mixed solution in sequence, and magnetic stirring is continued at 5 degrees to fully mix to obtain a mixture. The mixture is poured into a mold, placed in an environment with a temperature of 0 degrees, and allowed to stand for 12 hours. A slow cross-linking mode is adopted to solidify from the inside of the mixture to form a gel. The gel is then taken out and placed in an environment with a temperature of 15 degrees and an air humidity of 10%. It is left to dry and dehydrate naturally for 48 hours. The gel forms a porous structure to obtain a sodium alginate gel. The sodium alginate gel is placed in a 50 millimole per liter calcium chloride solution and fully soaked for 24 hours. The calcium ions swell by hydration. The method uses a metal ion to enter the interior of the sodium alginate gel to complete cross-linking and curing, thereby increasing the strength of the sodium alginate gel. The sodium alginate gel is then fully washed with deionized water. The sodium alginate gel is then immersed in a 100 millimole per liter metal salt solution and allowed to stand for 24 hours. The metal salt ions replace the calcium ions in the surface layer of the sodium alginate gel, thereby increasing the surface strength of the sodium alginate gel. Finally, the sodium alginate gel is fully washed with deionized water to obtain a high-strength sodium alginate gel. The prepared high-strength sodium alginate gel has the characteristics of high strength, high elastic modulus, and is not easy to decompose in water. By adopting the method of slow cross-linking, rehydration and re-cross-linking, and ion exchange and re-cross-linking, the sodium alginate gel is fully combined with the metal ions, thereby increasing the strength and elastic modulus of the hydrogel and making it not easy to decompose in water.

[0062] See also Figures 4 to 6 ,in Figure 4 This is a data chart of the elastic modulus of sodium alginate gel after cross-linking with different metal ions. Figure 5This is a data chart showing the tensile strength of sodium alginate gel after cross-linking with different metal ions. Figure 6 The present invention is a data chart showing the absorbance of human fibroblasts after co-culture with sodium alginate gel cross-linked with different metal ions. The metal salt solution is one of barium chloride, strontium chloride, aluminum chloride or ferric chloride.

[0063] In this embodiment, when the sodium alginate gel is immersed in a barium chloride salt solution, a strontium chloride solution, an aluminum chloride solution, or a ferric chloride solution, because these metal ions have different binding abilities with the gel, among which iron ions > aluminum ions > strontium ions > barium ions, through ion exchange, the metal salt ions will replace the calcium ions in the surface layer of the hydrogel. Therefore, according to different requirements of elastic modulus and tensile strength, different metal salt solutions can be used for immersion, and the final gel strength is different.

[0064] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of the rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for preparing high-strength sodium alginate gel, characterized in that: The steps include: Preparation of sodium alginate gel; The sodium alginate gel is placed in a 50-200 mmol / L calcium chloride solution and fully soaked; The sodium alginate gel is thoroughly washed with deionized water; Soaking the sodium alginate gel in a 100-400 mmol / L metal salt solution and allowing it to stand for 24-72 hours; The sodium alginate gel is fully washed with deionized water to obtain a high-strength sodium alginate gel; In the step of preparing sodium alginate gel, the preparation process is: Add 50-500 g of deionized water to 0.5-5 g of sodium alginate powder, heat and dissolve under magnetic stirring until clear and transparent to obtain a mixed solution; 0.05-0.4 g of calcium sulfate and 0.5-2 ml of acetic acid were sequentially added to the mixed solution, and magnetic stirring was continued at 5-50 degrees to fully mix to obtain a mixture; Pour the mixture into a mold, place it in an environment with a temperature of 0 to 10 degrees, and let it stand to form a gel; the standing temperature is 0 to 10 degrees and the standing time is 12 to 36 hours; The gel was taken out and placed for natural drying and dehydration to obtain sodium alginate gel.

2. The method for preparing high-strength sodium alginate gel according to claim 1, wherein: In the step of placing the sodium alginate gel in a 50-200 mmol / L calcium chloride solution and fully soaking it: The soaking time is 24 to 72 hours.

3. The method for preparing high-strength sodium alginate gel according to claim 1, wherein: In the step of immersing the sodium alginate gel in a 100-400 mmol / L metal salt solution and allowing it to stand for 24-72 hours: The metal salt solution is one of barium chloride, strontium chloride, aluminum chloride or ferric chloride.

4. The method for preparing high-strength sodium alginate gel according to claim 1, wherein: In the step of taking out the gel and placing it for natural drying and dehydration to obtain sodium alginate gel: The storage temperature is 15 to 30 degrees, the air humidity is 10 to 30%, and the storage time is 48 to 96 hours.

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