Preparation method of seaweed-based anti-evaporation substance porous material

Abstract

The invention discloses a preparation method of a seaweed-based anti-evaporation biomass porous material, which is characterized in that a seaweed-based biomass material is used as a raw material, and a composite material with a three-dimensional network structure is prepared mainly through chemical crosslinking and chemical etching methods; the preparation method specifically comprises the following steps: firstly, mixing seaweed-based biomass with sodium carbonate, uniformly stirring, freeze-drying, soaking in a calcium chloride solution to obtain a seaweed-based biomass / calcium carbonate composite material, soaking the prepared seaweed-based biomass / calcium carbonate composite material in a dilute acid solution, fully washing, and carrying out secondary drying to obtain the seaweed-based biomass / calcium carbonate composite material. The seaweed-based biomass-based porous sponge is obtained; the seaweed-based biomass porous sponge prepared by the method shows better hydrophilicity, compared with the seaweed-based biomass sponge prepared without an etching method, the porosity is improved by 5 times, and the seaweed-based biomass porous sponge prepared by the method can be applied to the fields of ecological environment restoration, water resource management and the like and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of biomaterial preparation, and in particular relates to a method for preparing a seaweed-based anti-evaporation biomass porous material. Background Art

[0002] Water is the basis for the survival and development of humans and other organisms. With the development of the global economy, the demand for water resources for industrial and agricultural development has increased dramatically, and water resources have become a strategic resource for development. Although the total amount of water resources is abundant, there are problems such as uneven distribution of water resources, large water consumption, and low water efficiency. Especially when there is less precipitation and large evaporation of surface water, limited water resources can no longer meet the needs of production and life. Therefore, strengthening the management of surface water in arid areas and reducing the evaporation of surface water are of great significance to alleviating the crisis of water resources in arid areas.

[0003] The covering method can effectively reduce the evaporation of surface water and improve the utilization rate of water resources, but most of the current covering materials have the problem of easy loss of long-term buoyancy. The present invention adopts an etching method to prepare a biomass-based porous sponge, and improves the self-floating performance of the anti-evaporation covering material by increasing the porosity. It is used in the field of anti-evaporation covering, which is of great significance for alleviating the ecological environment in arid areas.

[0004] Chinese patent CN110698722A discloses a method for preparing an oil-water separation type alginate aerogel with a nano-micron gradient hierarchical pore structure, wherein sodium carbonate is added to a sodium alginate foaming liquid, and then placed in a 3% calcium chloride solution for cross-linking for 24 hours to form an ultra-light sponge-like alginate aerogel with a fluffy porous structure. However, considering that there is still an organic cross-linking agent in the preparation process of the sponge-like alginate aerogel, the problem of excessive cross-linking agent remaining and difficult to remove exists, and the prior art appears to be slightly insufficient. The present invention does not need to use any organic cross-linking agent, and the excess cross-linking agent calcium chloride and etching agent used in the preparation process of seaweed-based biomass porous materials can be removed by washing, avoiding the problem of cross-linking agent remaining in the product. Summary of the invention

[0005] In view of the shortcomings of the existing anti-evaporation biomass porous material technology, such as easy loss of long-term buoyancy and poor self-floating stability, the present invention provides a method for preparing a seaweed-based anti-evaporation biomass porous material. The preparation method is a low-cost method for preparing a seaweed-based biomass porous sponge with good self-floating performance.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0007] A method for preparing a seaweed-based anti-evaporation biomass porous material comprises the following steps:

[0008] Step 1: Stir the seaweed-based biomass material, deionized water and sodium carbonate evenly;

[0009] Step 2: pouring into a petri dish and drying at low temperature to obtain a seaweed-based biomass material / sodium carbonate complex;

[0010] Step 3: Soaking the prepared seaweed-based biomass material / sodium carbonate complex in a calcium chloride solution;

[0011] Step 4: After taking out, wash with deionized water for 3-10 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0012] Step 5: The seaweed-based biomass material / calcium carbonate composite is soaked in dilute acid for calcium carbonate etching, washed to neutrality and then dried at low temperature to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0013] Furthermore, the raw material of the seaweed-based anti-evaporation biomass porous material in the first step also contains a surface modifier, and the weight proportions of the raw materials are: 20-60wt% seaweed-based biomass material, 10-30wt% sodium carbonate, 10-57wt% deionized water, and 0-3wt% surface modifier.

[0014] Furthermore, the seaweed-based biomass material is sodium alginate.

[0015] Furthermore, the dilute acid is hydrochloric acid and / or nitric acid, and the concentration of the dilute acid is 0.1-30wt%.

[0016] Furthermore, the surface modifier is one or more of hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and polyvinylpyrrolidone.

[0017] Furthermore, the stirring speed in the first step is 100-1000 rpm, and the stirring time is 10-720 minutes.

[0018] Furthermore, the calcium chloride concentration in the calcium chloride solution in the third step is 1-30%, and the soaking time in the calcium chloride solution is 0.1-24 hours.

[0019] Furthermore, the temperature of the second step low-temperature drying is -20 to -80°C, and the time of low-temperature drying is 12 to 48 hours.

[0020] Furthermore, after the seaweed-based biomass material / calcium carbonate composite is soaked in 0.1-30wt% dilute acid for 1-24 hours for calcium carbonate etching treatment, the seaweed-based biomass material is washed with deionized water for 5-10 times until neutral and then dried at low temperature.

[0021] Principle explanation: The present invention uses commercial seaweed-based biomass material (sodium alginate) and sodium carbonate as raw materials, and prepares a seaweed-based biomass material / calcium carbonate complex through a chemical reaction with calcium chloride. The placeholder calcium carbonate is then removed by dilute acid etching. After low-temperature drying, a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge, can be obtained.

[0022] Compared with the prior art, the beneficial effects of the present invention include:

[0023] 1. The seaweed-based biomass porous sponge obtained by the present invention exhibits good hydrophilicity, and the porosity is increased by about 5 times compared with the seaweed-based biomass sponge prepared without using the etching method.

[0024] 2. In the preparation process of the biomass-based porous sponge by etching method of the present invention, the use of organic solvents is avoided, and the production process is green and environmentally friendly. In addition, sodium alginate is extracted from kelp or sargassum of brown algae, and the raw materials are easy to obtain. The entire preparation has the advantages of simple operation and short production cycle, which is conducive to the further promotion and application of seaweed-based biomass anti-evaporation materials.

[0025] 3. The seaweed-based biomass porous sponge obtained by the present invention floats on the liquid surface in a tightly arranged manner, and has the best anti-evaporation effect, with an evaporation inhibition rate of 95%. This research result has positive significance for reducing evaporation losses of water resources and improving water resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a scanning electron microscope (SEM) image of the seaweed-based anti-evaporation biomass porous material described in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described below in conjunction with embodiments. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0028] In the following examples, unless otherwise specified, "concentration" refers to mass percentage.

[0029] Example 1

[0030] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0031] Step 1: Pour 30wt% of sodium alginate, 20wt% of sodium carbonate and 50wt% of deionized water into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0032] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0033] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 1% calcium chloride solution for 0.1 hour;

[0034] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0035] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 0.1% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0036] Example 2

[0037] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0038] Step 1: Pour 30wt% of sodium alginate, 20wt% of sodium carbonate, 49wt% of deionized water and 1wt% of cetyltrimethylammonium bromide into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0039] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0040] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 10% calcium chloride solution for 1 hour;

[0041] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0042] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0043] Example 3

[0044] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0045] Step 1: Pour 30wt% sodium alginate, 20wt% sodium carbonate, 49wt% deionized water and 1wt% sodium dodecyl sulfate into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0046] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0047] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 10% calcium chloride solution for 1 hour;

[0048] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0049] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0050] Example 4

[0051] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0052] Step 1: Add 30wt% sodium alginate, 20wt% sodium carbonate, 49wt% deionized water and 1wt% polyvinyl pyrrolidone into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0053] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0054] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 10% calcium chloride solution for 1 hour;

[0055] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0056] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0057] Example 5

[0058] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0059] Step 1: Pour 40wt% of sodium alginate, 10wt% of sodium carbonate, 49wt% of deionized water and 1wt% of hexadecyltrimethylammonium bromide into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0060] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0061] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 10% calcium chloride solution for 1 hour;

[0062] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0063] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0064] Example 6

[0065] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0066] Step 1: Pour 40wt% of sodium alginate, 10wt% of sodium carbonate, 49wt% of deionized water and 1wt% of hexadecyltrimethylammonium bromide into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0067] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0068] Step 3: Soaking the prepared seaweed-based biomass material / sodium carbonate complex in a 5% calcium chloride solution for 12 hours;

[0069] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0070] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0071] Example 7

[0072] A method for preparing a seaweed-based anti-evaporation biomass porous material, comprising the following specific steps:

[0073] Step 1: Pour 40wt% of sodium alginate, 10wt% of sodium carbonate, 49wt% of deionized water and 1wt% of hexadecyltrimethylammonium bromide into a beaker and stir evenly at a stirring speed of 500 rpm for 120 minutes;

[0074] Step 2: Pour into a petri dish and dry at -80°C for 24 hours to obtain a seaweed-based biomass material / sodium carbonate complex;

[0075] Step 3: Soak the prepared seaweed-based biomass material / sodium carbonate complex in a 20% calcium chloride solution for 1 hour;

[0076] Step 4: After taking out, wash with deionized water 5 times to obtain a seaweed-based biomass material / calcium carbonate composite;

[0077] Step 5: After the seaweed-based biomass material / calcium carbonate composite is soaked and etched in 10% dilute acid to remove the spacer calcium carbonate, it is washed with deionized water for 5 times until it is neutral and low-temperature dried at -80°C for 24 hours to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

[0078] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a seaweed-based anti-evaporation biomass porous material, characterized in that: The following steps are involved: Step 1: Stir the seaweed-based biomass material, deionized water and sodium carbonate evenly; Step 2: pouring into a petri dish and drying at low temperature to obtain a seaweed-based biomass material / sodium carbonate complex; Step 3: Soaking the prepared seaweed-based biomass material / sodium carbonate complex in a calcium chloride solution; Step 4: After taking out, wash with deionized water for 3-10 times to obtain a seaweed-based biomass material / calcium carbonate composite; Step 5: The seaweed-based biomass material / calcium carbonate composite is soaked in dilute acid for calcium carbonate etching, washed to neutrality and then dried at low temperature to obtain a seaweed-based anti-evaporation biomass porous material, i.e., a seaweed-based biomass sponge.

2. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: In the first step, the raw material of the seaweed-based anti-evaporation biomass porous material also contains a surface modifier, and the weight proportions of the raw materials are: 20-60wt% of seaweed-based biomass material, 10-30wt% of sodium carbonate, 10-57wt% of deionized water, and 0-3wt% of the surface modifier.

3. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: The seaweed-based biomass material is sodium alginate.

4. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: The dilute acid is hydrochloric acid and / or nitric acid, and the concentration of the dilute acid is 0.1-30wt%.

5. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 2, characterized in that: The surface modifier is one or more of hexadecyltrimethylammonium bromide, sodium lauryl sulfate and polyvinyl pyrrolidone.

6. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: The stirring speed of the first step is 100-1000 rpm, and the stirring time is 10-720 minutes.

7. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: The calcium chloride concentration in the calcium chloride solution in the third step is 1-30%, and the soaking time in the calcium chloride solution is 0.1-24 hours.

8. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 1, characterized in that: The temperature of the low-temperature drying in the second step and the fifth step is -20 to -80°C, and the time of the low-temperature drying is 12 to 48 hours.

9. The method for preparing the seaweed-based anti-evaporation biomass porous material according to claim 4, characterized in that: The seaweed-based biomass material / calcium carbonate composite is soaked in 0.1-30wt% dilute acid for 1-24 hours for calcium carbonate etching treatment, and then the seaweed-based biomass material is washed with deionized water for 5-10 times until neutral and then dried at low temperature.

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