Honeycomb-shaped alginic acid oleogel fabric for collecting water in atmosphere and preparation method of honeycomb-shaped alginic acid oleogel fabric

Abstract

The invention discloses a honeycomb-shaped alginic acid oil gel fabric for collecting water in the atmosphere and a preparation method of the honeycomb-shaped alginic acid oil gel fabric, and belongs to the field of water collection. The honeycomb-shaped alginic acid oleogel fabric is obtained by mixing sodium alginate, a photothermal conversion material (carbon black / graphene / Mxene) and deionized water, spinning, replacing by polyhydric alcohols such as glycerol and weaving by a weaving machine. Under the relative humidity of 30%, 60% and 90%, the moisture absorption efficiency of the honeycomb-shaped alginic acid oil gel fabric can reach 1.95 g / g, 3.92 g / g and 5.65 g / g respectively. The preparation method is simple and convenient to operate, and the prepared honeycomb-shaped alginic acid oil gel fabric for atmospheric water collection has the advantages of high moisture absorption and evaporation rate and high long-term stability, can be used for atmospheric water collection, solves the problem of lack of water resources in arid and semi-arid regions, and has potential commercial value and application prospect.

Description

Technical Field

[0001] The invention relates to a honeycomb-shaped alginate oil gel fabric for atmospheric water collection and a preparation method thereof, belonging to the technical field of functional materials. Background Art

[0002] Life cannot function without water. A stable, portable and high-yield supply of clean water is extremely important, especially in emergency situations or remote arid areas. Atmospheric water in the form of vapor and droplets is a huge untapped freshwater resource, equivalent to one-eighth of the total freshwater resources in rivers, lakes and reservoirs. Harvesting this neglected but ubiquitous water resource in the atmosphere is considered a potential way to alleviate water shortages.

[0003] The methods of atmospheric water collection can be mainly divided into two types: physical adsorption and chemical adsorption. Among them, chemical adsorption generally has the characteristics of high adsorption rate and low desorption temperature, and is considered to be the main means of atmospheric water collection. Recently, some studies have shown that atmospheric water collection materials prepared by loading hygroscopic metal salts inside hydrogels with photothermal conversion effects can absorb water molecules in the air and use solar energy to desorb to obtain fresh water. However, due to the poor bonding between metal salts and traditional hydrogels, the salt solution leaks from the inside of the hydrogel during the moisture absorption process, causing the water collection efficiency of the atmospheric water collection device to gradually decrease, and the sustainable utilization is low. In addition, the physical structure of the atmospheric water collection material is basically blocky, and a large amount of solar energy is wasted during the desorption process. The above problems make it difficult for atmospheric water collection materials to be used. Therefore, it is necessary to design an atmospheric water collection material with stable moisture absorption / desorption. Summary of the invention

[0004]

Technical issues

[0005] In order to solve the above problems, the present invention provides a honeycomb alginate oil gel fabric for atmospheric water collection and a preparation method thereof, the method uses sodium alginate as a raw material, doped with carbon black / graphene / Mxene to give photothermal properties, uses calcium chloride for cross-linking to obtain alginate gel fiber, and then replaces it with glycerol / propylene glycol / butylene glycol to give it hygroscopic properties and improve mechanical properties, and finally uses a loom to weave the alginate oil gel fiber into alginate oil gel fabric to enhance its desorption rate. The present invention cross-links sodium alginate solution with calcium chloride solution, further performs solvent replacement reaction on alginate oil gel fiber, and finally obtains a honeycomb sodium alginate oil gel fabric by weaving on a loom. The preparation method of the present invention is simple in process and easy to scale up. The obtained honeycomb sodium alginate oil gel fabric has good mechanical properties and excellent atmospheric water collection / desorption performance, and has good application prospects in many application fields such as atmospheric water collection, soft materials, flexible electronics, sensors, wearable devices, tissue engineering and biomedical applications.

[0006]

Technical solution

[0007] The first object of the present invention is to provide a method for preparing a honeycomb sodium alginate oil gel fabric that can be used for atmospheric water collection, comprising the following steps:

[0008] (1) Preparation of alginate hydrogel fibers: extruding a spinning solution containing sodium alginate into a calcium chloride solution to obtain alginate hydrogel fibers;

[0009] (2) Preparation of alginate oil gel fiber: taking an appropriate amount of the alginate hydrogel fiber prepared in step (1), placing it in a polyol for replacement, and leaving it at room temperature for a period of time to obtain alginate oil gel fiber;

[0010] (3) Preparation of honeycomb sodium alginate oil gel fabric: Take an appropriate amount of the alginate oil gel fiber prepared in step (2) and weave it on a loom to obtain a honeycomb sodium alginate oil gel fabric.

[0011] As one embodiment of the present invention, the step (1) specifically includes the following steps:

[0012] S1: adding sodium alginate and photothermal conversion material into deionized water and stirring to obtain a spinning solution containing sodium alginate; wherein the mass ratio of sodium alginate:photothermal conversion material:water in the spinning solution is 2-8:0.2-0.8:100;

[0013] S2: extruding the spinning solution containing sodium alginate into a calcium chloride solution to cause a cross-linking reaction;

[0014] S3: taking out the gel fiber obtained after the reaction, washing it with deionized water, and obtaining alginate hydrogel fiber.

[0015] As one embodiment of the present invention, the mass fraction of sodium alginate in the spinning solution containing sodium alginate in step (1) should be 2wt% to 8wt%.

[0016] As one embodiment of the present invention, the photothermal conversion material is at least one of carbon black, graphene, and Mxene.

[0017] As one embodiment of the present invention, the concentration of the calcium chloride solution should be 2wt% to 8wt%.

[0018] As one embodiment of the present invention, the reaction temperature in step (1) is 5°C to 75°C, and the reaction time is 5-10 min.

[0019] As one embodiment of the present invention, the aperture of the needle used to extrude the spinning solution containing sodium alginate should be 0.5 to 5 mm.

[0020] As one embodiment of the present invention, the polyol in step (2) is any one or more of glycerol, propylene glycol, and butylene glycol.

[0021] As one embodiment of the present invention, in the step (2), the bath ratio of the alginate hydrogel fiber to the polyol is 1 g: 10-100 mL.

[0022] As one embodiment of the present invention, the replacement time of the alginate hydrogel fiber and the polyol in step (2) should be more than 10 hours.

[0023] As one embodiment of the present invention, step (3) specifically includes the following steps:

[0024] The alginate oil gel fiber is woven by a loom in a honeycomb structure to obtain a honeycomb alginate oil gel fabric for atmospheric water collection.

[0025] The second object of the present invention is to provide a honeycomb alginate oil gel fabric for atmospheric water collection prepared by the aforementioned method.

[0026] The third object of the present invention is to provide the use of the aforementioned honeycomb-shaped alginate oil gel fabric in atmospheric water collection.

[0027] Beneficial effects of the present invention:

[0028] (1) The preparation method of the present invention is simple in process and easy to operate, and can be expanded to large-scale preparation.

[0029] (2) The honeycomb alginate oil gel fabric prepared by the present invention has excellent hygroscopic properties and can directly capture and store water molecules in the air inside the alginate oil gel fabric. At a relative humidity of 30%, 60%, and 90%, 1.95, 3.92, and 5.65 g / cm2 of water molecules can be collected, respectively. -1 of fresh water.

[0030] (3) The honeycomb alginate oil gel fabric prepared by the present invention has excellent photothermal properties: it can quickly heat up under sunlight and convert the captured water into water vapor, with a desorption rate of up to 0.04 kg m -2 min -1 .

[0031] (4) The honeycomb-shaped alginate oil gel fabric prepared by the present invention can be used as a high-quality and efficient atmospheric water collection material for atmospheric water collection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1The moisture absorption rate of the honeycomb-shaped alginate oil gel fabric for atmospheric water collection formed in the present invention at different humidity levels.

[0033] Figure 2 It is the moisture absorption rate of the honeycomb-shaped alginate oil gel fabric for atmospheric water collection of the present invention after ten cycles at a relative humidity of 90%.

[0034] Figure 3 These are electron microscope pictures of the honeycomb-shaped alginate oil gel fabric for atmospheric water collection described in the present invention before and after being doped with carbon black.

[0035] Figure 4 It is the moisture absorption rate of the honeycomb alginate oil gel fabric and the honeycomb alginate hydrogel fabric of the present invention at a relative humidity of 90%.

[0036] Figure 5 The temperature variation of the honeycomb alginate oil gel fabric and the plain alginate oil gel fabric described in the present invention under the irradiation of sunlight of the same intensity. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0038] Test method:

[0039] 1. Morphology test: Scanning electron microscopy (SEM, Hitachi Su1510 Co., Ltd., Japan) was used to characterize the morphology of the samples.

[0040] 2. Infrared testing: The functional groups of the samples were characterized by Fourier transform infrared spectrometer (FTIR, Thermo Fisher Scientific IS50).

[0041] 3. Moisture absorption test: The moisture absorption performance of the samples was tested using a constant temperature and humidity chamber (YG601H-II, Ningbo Textile Instrument Factory).

[0042] 4. Water evaporation test: The sample was irradiated with a xenon lamp (Cel-S500) equipped with an AM 1.5 filter to simulate sunlight. At the same time, a solar meter (SM206-Solar) was used to calibrate the sunlight intensity to maintain at one sun (1000W m -2 ), an electronic balance (AX224ZH / E) recorded the mass loss of water in the beaker to measure the interfacial evaporation capacity of the aerogel sample.

[0043] 5. Photothermal desorption performance test: The changes in sample surface temperature and mass during the interface evaporation process were recorded by a thermal imager (Testo 871, Testo Se&Co.Kgaa) and an electronic balance (Sartorius CP224S).

[0044] Example 1

[0045] A method for preparing a honeycomb oil gel fabric for atmospheric water collection comprises the following steps:

[0046] (1) Weigh 4 g of sodium alginate powder, 0.4 g of carbon black powder and 100 mL of deionized water into a 200 mL beaker and mechanically stir for 6 hours at 25°C. Then, the sodium alginate mixed solution was left to stand at room temperature for 24 hours to remove internal bubbles.

[0047] (2) Weigh 4 g of calcium chloride powder, add 100 mL of deionized water and mechanically stir at room temperature for 10 min to obtain a calcium chloride aqueous solution;

[0048] (3) The sodium alginate mixed solution is continuously squeezed into the calcium chloride solution through a syringe pump to obtain alginate hydrogel fibers.

[0049] (4) The alginate hydrogel fiber is immersed in a glycerol solution for displacement for 24 hours, and the glycerol remaining on the surface is taken out and wiped off to obtain the alginate oil gel fiber.

[0050] (5) The alginate oil gel fiber is woven using a loom in a honeycomb structure to obtain a honeycomb alginate oil gel fabric.

[0051] Example 2

[0052] A method for preparing a honeycomb oil gel fabric for atmospheric water collection comprises the following steps:

[0053] (1) Weigh 4 g of sodium alginate powder, 0.4 g of graphene powder and 100 mL of deionized water into a 200 mL beaker and mechanically stir for 6 hours at 25°C. Then, the sodium alginate mixed solution was left to stand at room temperature for 24 hours to remove internal bubbles.

[0054] (2) Weigh 4 g of calcium chloride powder, add 100 mL of deionized water and mechanically stir at room temperature for 10 min to obtain a calcium chloride aqueous solution;

[0055] (3) The sodium alginate mixed solution is continuously squeezed into the calcium chloride solution through a syringe pump to obtain alginate hydrogel fibers.

[0056] (4) The alginate hydrogel fiber is immersed in a butanediol solution for displacement for 24 hours, and the butanediol remaining on the surface is taken out and wiped off to obtain the alginate oil gel fiber.

[0057] (5) The alginate oil gel fiber is woven using a loom in a honeycomb structure to obtain a honeycomb alginate oil gel fabric.

[0058] Example 3

[0059] A method for preparing a honeycomb oil gel fabric for atmospheric water collection comprises the following steps:

[0060] (1) Weigh 4 g of sodium alginate powder, 0.4 g of carbon black powder and 100 mL of deionized water into a 200 mL beaker and mechanically stir for 6 hours at 25°C. Then, the sodium alginate mixed solution was left to stand at room temperature for 24 hours to remove internal bubbles.

[0061] (2) Weigh 4 g of calcium chloride powder, add 100 mL of deionized water and mechanically stir at room temperature for 10 min to obtain a calcium chloride aqueous solution;

[0062] (3) The sodium alginate mixed solution is continuously squeezed into the calcium chloride solution through a syringe pump to obtain alginate hydrogel fibers.

[0063] (4) The alginate hydrogel fiber is immersed in a butanediol solution for displacement for 24 hours, and the butanediol remaining on the surface is taken out and wiped off to obtain the alginate oil gel fiber.

[0064] (5) The alginate oil gel fiber is woven using a loom in a honeycomb structure to obtain a honeycomb alginate oil gel fabric.

[0065] 1. Moisture absorption test

[0066] The honeycomb alginate oil gel fabric for atmospheric water collection of Example 1 was tested for atmospheric water collection, and the results were as follows: Figure 1 Curves at different humidity and Figure 2 Moisture absorption curve after 10 cycles.

[0067] Figure 1 The moisture absorption curves of honeycomb alginate oil gel fabric for atmospheric water collection at 30%, 60%, and 90% relative humidity. Figure 1 It can be seen that at a relative humidity of 30%, 60% and 90%, the moisture absorption efficiency of the honeycomb alginate oil gel fabric can reach 1.95, 3.92, 5.65 g / cm2, respectively. -1 The results show that at different humidity levels, the samples can collect fresh water from the air, proving that the honeycomb oil gel fabric has good moisture absorption properties.

[0068] The honeycomb oil gel fabric was also subjected to 10 consecutive moisture absorption tests at a relative humidity of 90%. Figure 2As shown in the figure, it can be seen that after multiple cycles of moisture absorption, the moisture absorption performance of the sample did not decrease significantly, indicating that the atmospheric water collection performance of the honeycomb oil gel fabric is very stable.

[0069] Comparative Example 1

[0070] The carbon black in step (1) of Example 1 was omitted, and the other steps were the same as in Example 1 to obtain a honeycomb oil gel fabric.

[0071] Comparative Example 2

[0072] The glycerol replacement process in step (4) of Example 1 was omitted, and the rest was kept the same as in Example 1 to obtain a honeycomb hydrogel fabric.

[0073] Comparative Example 3

[0074] The honeycomb weave structure in step (5) of Example 1 was changed to a plain weave structure, and the rest was kept the same as Example 1 to obtain a plain weave oil gel fabric.

[0075] 2. Morphology comparison

[0076] The products obtained in Example 1 and Comparative Example 1 were tested for morphology. To obtain accurate morphology, the products were freeze-dried. The results are as follows: Figure 1 As shown. Figure 3 (a) is a single carbon black-doped honeycomb alginate oil gel fiber of Example 1, Figure 3 (b) is the alginate oil gel fabric of Comparative Example 1 which is not doped with carbon black.

[0077] from Figure 3 It can be seen that both products have a porous three-dimensional structure. Compared with the other samples, it can be seen that there are a large number of carbon black particles on the surface of a single carbon black-doped alginate oil gel fiber. This is conducive to the efficient photothermal conversion of the sample during the solar desorption process, thereby enhancing the water evaporation rate.

[0078] 3. Comparison of moisture absorption performance

[0079] The hygroscopicity test of the products obtained in Example 1 and Comparative Example 2 was carried out respectively, and the results were as follows: Figure 4 shown.

[0080] from Figure 4 It can be seen that the honeycomb alginate oil gel fabric has a strong hygroscopic property because of the glycerol inside. It can absorb water molecules in the air and store them inside the oil gel. At a relative humidity of 90%, it can reach 5.65gg within 720min. -1 In the absence of glycerol, the honeycomb alginate hydrogel fabric can only reach 0.76 gg -1The results show that the honeycomb alginate oil gel fabric has excellent moisture absorption performance and is suitable for atmospheric water collection.

[0081] 4. Comparison of Photothermal Performance

[0082] The photothermal evaporation performance of the products obtained in Example 1 and Comparative Example 3 was tested respectively, and the results were as follows: Figure 5 shown.

[0083] from Figure 5 It can be seen that as the sunlight exposure time increases, the temperature of the surface of the honeycomb alginate oil gel fabric continues to increase, and it only takes 60 minutes to increase the temperature from 25°C to 69°C, while under the same conditions, the plain alginate oil gel fabric can only be heated to 62.5°C. It proves that the honeycomb alginate oil gel fabric has excellent heating performance. It shows that the honeycomb alginate oil gel fabric has excellent photothermal performance and is suitable for atmospheric water collection.

[0084] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing alginate oil gel fabric for atmospheric water collection, characterized in that: The following steps are included in sequence: (1) sodium alginate and calcium chloride undergo a cross-linking reaction to prepare a fibrous alginate hydrogel; (2) soaking the fibrous alginate hydrogel prepared in step (1) in a polyol for replacement to prepare a fibrous alginate oil gel; (3) Based on the fibrous alginate oil gel prepared in step (2), a honeycomb alginate oil gel fabric is prepared by using a loom.

2. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 1, characterized in that: The step (1) specifically comprises the following steps: S1: adding sodium alginate and photothermal conversion material into deionized water and mechanically stirring to obtain a spinning solution; wherein the mass ratio of sodium alginate:photothermal conversion material:water in the spinning solution is 2-8:0.2-0.8:100; S2: adding calcium chloride to deionized water and mechanically stirring to obtain a calcium chloride solution; wherein the concentration of the calcium chloride solution should be 2wt% to 8wt%; S3: taking out the gel fiber obtained after the reaction, washing it with deionized water, and obtaining alginate hydrogel fiber.

3. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 2, characterized in that: The photothermal conversion material is at least one of carbon black, graphene and Mxene.

4. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 1, characterized in that: The reaction conditions in step (1) are: temperature of 5°C to 75°C and time of 5-60 min.

5. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 1, characterized in that: The step (2) specifically comprises the following steps: The alginate hydrogel fiber is soaked in polyol for displacement, taken out and dried to obtain the alginate oil gel fiber; the polyol is any one or more of propylene glycol, propylene glycol and butylene glycol.

6. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 5, characterized in that: The bath ratio of the alginate hydrogel to the polyol in step S3 is 1 g: 10-100 mL.

7. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 5, characterized in that: The replacement time of the alginate hydrogel and the polyol in step S3 is more than 10 hours.

8. The method for preparing alginate oil gel fabric for atmospheric water collection according to claim 1, characterized in that: The step (3) specifically comprises the following steps: The alginate oil gel fiber is woven by a loom in a honeycomb structure to obtain alginate oil gel fabric for atmospheric water collection.

9. Alginate oil gel fabric for atmospheric water collection prepared by the method according to any one of claims 1 to 8.

10. Application of the alginate oil gel fabric for atmospheric water collection as claimed in claim 9 in many fields such as water collection, soft materials, flexible electronics, sensors, wearable devices, tissue engineering and biomedical applications.

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