A honeycomb-like alginate oil gel fabric for atmospheric water harvesting and a method of making the same

Abstract

The application discloses a honeycomb alginate oil gel fabric for atmospheric water collection and a preparation method thereof, and belongs to the field of water collection. The honeycomb alginate oil gel fabric is obtained by spinning after mixing sodium alginate, a light-heat conversion material (carbon black / graphene / Mxene) and deionized water, and then replacing with polyhydric alcohols such as glycerol and weaving by a loom. The moisture absorption efficiency of the honeycomb alginate oil gel fabric can reach 1.95, 3.92 and 5.65 g g ‑1 The application is simple in operation, and the prepared honeycomb alginate oil gel fabric for atmospheric water collection has the advantages of fast moisture absorption and evaporation rate, high long-term stability, and can be used for atmospheric water collection, improves the problem of lack of water resources in arid and semi-arid areas, and has potential commercial value and application prospect.

Description

Technical Field

[0001] This invention relates to a honeycomb-shaped alginate oleogel fabric for atmospheric water collection and its preparation method, belonging to the field of functional materials technology. Background Technology

[0002] Water is essential for the activities of living organisms. A stable, portable, and high-yield supply of clean water is extremely important, especially in emergencies or in remote, arid regions. Atmospheric water, existing in the form of vapor and droplets, represents a vast, untapped freshwater resource, equivalent to one-eighth of the total freshwater resources in rivers and lakes. Harvesting this often overlooked yet ubiquitous water resource in the atmosphere is considered a potential method for alleviating water scarcity.

[0003] Atmospheric water collection methods can be mainly divided into two types: physical adsorption and chemical adsorption. Chemical adsorption, generally characterized by high adsorption rates and low desorption temperatures, is considered the primary method for atmospheric water collection. Recently, some studies have shown that atmospheric water-collecting materials prepared by loading hygroscopic metal salts onto hydrogels with photothermal conversion effects can absorb water molecules from the air and desorb them using solar energy to obtain fresh water. However, due to the poor binding between the metal salts and traditional hydrogels, the salt solution leaks from the hydrogel during the hygroscopic process, causing a gradual decrease in the water collection efficiency of the atmospheric water collection device and low sustainability. Furthermore, the physical structure of atmospheric water-collecting materials is basically blocky, wasting a significant amount of solar energy during desorption. These problems hinder the application of atmospheric water-collecting materials. Therefore, it is necessary to design an atmospheric water-collecting material with stable hygroscopic / desorption properties. Summary of the Invention

[0004] [Technical Issues]

[0005] To address the aforementioned problems, this invention provides a honeycomb-shaped alginate oleogel fabric for atmospheric water collection and its preparation method. The method uses sodium alginate as a raw material, doping it with carbon black / graphene / Mxene to impart photothermal properties, cross-linking it with calcium chloride to obtain alginate gel fibers, then replacing them with glycerol / propylene glycol / butanediol to impart hygroscopic properties and improve mechanical properties. Finally, the alginate oleogel fibers are woven into an alginate oleogel fabric using a loom to enhance its desorption rate. This invention involves cross-linking sodium alginate solution with calcium chloride solution, further performing a solvent replacement reaction to obtain alginate oleogel fibers, and finally weaving them to obtain a honeycomb-shaped sodium alginate oleogel fabric. The preparation method of this invention is simple, easily scalable, and the resulting honeycomb-shaped sodium alginate oleogel fabric exhibits good mechanical properties and excellent atmospheric water collection / desorption performance, showing promising application prospects in many fields such as atmospheric water collection, soft materials, flexible electronics, sensors, wearable devices, tissue engineering, and biomedical applications.

[0006] [Technical Solution]

[0007] The first objective of this invention is to provide a method for preparing a honeycomb-shaped sodium alginate oleogel fabric suitable for atmospheric water collection, comprising the following steps:

[0008] (1) Preparation of alginate hydrogel fiber: The spinning solution containing sodium alginate was extruded into calcium chloride solution to obtain alginate hydrogel fiber.

[0009] (2) Preparation of alginate oleogel fiber: Take an appropriate amount of alginate hydrogel fiber prepared in step (1), place it in a polyol for replacement, and place it at room temperature for a period of time to obtain alginate oleogel fiber.

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

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

[0012] S1: Add sodium alginate and photothermal conversion material to deionized water and stir 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: The spinning solution containing sodium alginate is extruded into the calcium chloride solution to undergo a cross-linking reaction;

[0014] S3: Take out the gel fiber obtained after the reaction, wash it with deionized water, and obtain alginate hydrogel fiber.

[0015] In 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] In one embodiment of the present invention, the photothermal conversion material is at least one of carbon black, graphene, and Mxene.

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

[0018] In one embodiment of the present invention, the reaction temperature in step (1) is 5℃~75℃ and the reaction time is 5-10min.

[0019] In one embodiment of the present invention, the needle orifice diameter for extruding the spinning solution containing sodium alginate should be 0.5 to 5 mm.

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

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

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

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

[0024] Honeycomb-shaped alginate oleogel fabric for atmospheric water collection is obtained by weaving alginate oleogel fibers into a honeycomb structure using a loom.

[0025] A second objective of the present invention is to provide a honeycomb-shaped alginate oleogel fabric for atmospheric water collection, prepared by the aforementioned method.

[0026] A third objective of the present invention is to provide the application of the aforementioned honeycomb alginate oleogel fabric in atmospheric water collection.

[0027] The beneficial effects of this invention are:

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

[0029] (2) The honeycomb-shaped alginate oleogel fabric prepared by this invention has excellent moisture absorption properties, and can directly capture and store water molecules in the air inside the alginate oleogel fabric. At relative humidity levels of 30%, 60%, and 90%, it can collect 1.95, 3.92, and 5.65 g of water, respectively. -1 Freshwater.

[0030] (3) The honeycomb-shaped alginate oleogel fabric prepared by this invention has excellent photothermal properties: it can rapidly heat up under sunlight and convert the captured water into water vapor, with a desorption rate of up to 0.04 kg m³. -2 min -1 .

[0031] (4) The honeycomb-shaped alginate oleogel fabric prepared by the present invention can be used as a high-quality and efficient atmospheric water collection material for atmospheric water collection. Attached Figure Description

[0032] Figure 1The moisture absorption rate of the honeycomb-shaped alginate oleogel fabric for atmospheric water collection described in this invention is measured under different humidity levels.

[0033] Figure 2 The moisture absorption rate of the honeycomb alginate oleogloss fabric for atmospheric water collection, as described in this invention, after ten cycles at 90% relative humidity.

[0034] Figure 3 These are electron microscope images of the honeycomb alginate oleogel fabric for atmospheric water collection described in this invention before and after carbon black doping.

[0035] Figure 4 The moisture absorption rate of the honeycomb alginate oleogel fabric and the honeycomb alginate hydrogel fabric described in this invention at 90% relative humidity.

[0036] Figure 5 The temperature changes of the honeycomb-shaped alginate oleogel fabric and the plain-weave alginate oleogel fabric described in this invention under a single solar radiation intensity. Detailed Implementation

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

[0038] Test method:

[0039] 1. Morphology test: The morphology of the sample was characterized by scanning electron microscopy (SEM, Hitachi Su1510 Co., Ltd., Japan).

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

[0041] 3. Moisture absorption test: The moisture absorption performance of the sample 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. Simultaneously, a solar energy meter (SM206-Solar) was used to calibrate and maintain the sunlight intensity at a level of 1000 W / m². -2 An electronic balance (AX224ZH / E) was used to record 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 interfacial evaporation were recorded using 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-shaped oleogel fabric for atmospheric water collection includes the following steps:

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

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

[0048] (3) The sodium alginate mixture was continuously injected into the calcium chloride solution through an injection pump to obtain alginate hydrogel fibers.

[0049] (4) Soak the alginate hydrogel fiber in a glycerol solution for 24 hours, remove it and wipe off the residual glycerol on the surface to obtain alginate oleogel fiber.

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

[0051] Example 2

[0052] A method for preparing a honeycomb-shaped oleogel fabric for atmospheric water collection includes the following steps:

[0053] (1) Weigh 4g of sodium alginate powder, 0.4g of graphene powder, and 100mL of deionized water into a 200ml beaker and stir mechanically at 25℃ for 6 hours. Then let the sodium alginate mixture stand at room temperature for 24 hours to remove internal air bubbles.

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

[0055] (3) The sodium alginate mixture was continuously injected into the calcium chloride solution through an injection pump to obtain alginate hydrogel fibers.

[0056] (4) Soak the alginate hydrogel fiber in butylene glycol solution for 24 hours, remove it and wipe off the residual butylene glycol on the surface to obtain alginate oleogel fiber.

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

[0058] Example 3

[0059] A method for preparing a honeycomb-shaped oleogel fabric for atmospheric water collection includes the following steps:

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

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

[0062] (3) The sodium alginate mixture was continuously injected into the calcium chloride solution through an injection pump to obtain alginate hydrogel fibers.

[0063] (4) Soak the alginate hydrogel fiber in butylene glycol solution for 24 hours, remove it and wipe off the residual butylene glycol on the surface to obtain alginate oleogel fiber.

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

[0065] I. Moisture Absorption Test

[0066] Atmospheric water collection was tested on the honeycomb alginate oleogel fabric for atmospheric water collection in Example 1, and the results were obtained. Figure 1 Curves under different humidity levels and Figure 2 The moisture absorption curve after 10 cycles.

[0067] Figure 1 These are the moisture absorption curves of a honeycomb-shaped alginate oleogel fabric used for atmospheric moisture collection at relative humidity levels of 30%, 60%, and 90%. From... Figure 1 It can be seen that at relative humidity levels of 30%, 60%, and 90%, the moisture absorption efficiencies of this honeycomb-shaped alginate oleoglucoate fabric can reach 1.95, 3.92, and 5.65 g / L, respectively. -1 This indicates that the samples were able to collect fresh water from the air under various humidity levels, demonstrating that the honeycomb oleogel fabric has excellent moisture absorption properties.

[0068] The honeycomb-shaped oleogel fabric was also subjected to 10 consecutive moisture absorption tests at a relative humidity of 90%, and the results were as follows: Figure 2As shown in the figure, the moisture absorption performance of the sample did not decrease significantly after multiple cycles of moisture absorption, indicating that the atmospheric water collection performance of the honeycomb oleogel fabric is very stable.

[0069] Comparative Example 1

[0070] Omit the carbon black in step (1) of Example 1, and keep everything else the same as in Example 1 to obtain a honeycomb oleogel fabric.

[0071] Comparative Example 2

[0072] The glycerol replacement process in step (4) of Example 1 is omitted, and the rest is 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, while the rest remained the same as in Example 1, resulting in a plain weave oleogel fabric.

[0075] II. Morphological Comparison

[0076] The morphology of the products obtained in Example 1 and Comparative Example 1 was tested. To obtain accurate morphology, the products were freeze-dried. The results are as follows: Figure 1 As shown. Among them. Figure 3 (a) is a single carbon black-doped honeycomb alginate oleogel fiber from Example 1. Figure 3 (b) is an alginate oleogel fabric without carbon black as a comparative example 1.

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

[0078] III. Comparison of Moisture Absorption Performance

[0079] The moisture absorption properties of the products prepared in Example 1 and Comparative Example 2 were tested respectively, and the results were as follows: Figure 4 As shown.

[0080] from Figure 4 It can be seen that the honeycomb-shaped alginate oleogel fabric, due to the extremely strong hygroscopic properties of its internal glycerol, can adsorb water molecules from the air and store them inside the oleogel. At 90% relative humidity, it can reach 5.65 g / m³ within 720 minutes. -1 The moisture absorption capacity. Without glycerin, the honeycomb alginate hydrogel fabric can only achieve 0.76 g / m³. -1The moisture absorption capacity indicates that the honeycomb alginate oleogloss fabric has excellent moisture absorption properties and is suitable for atmospheric moisture collection.

[0081] IV. Comparison of Photothermal Performance

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

[0083] from Figure 5 It can be seen that with the increase of sunlight exposure time, the surface temperature of the honeycomb-shaped alginate oleogel fabric continuously increases, rising from 25℃ to 69℃ in just 60 minutes. Under the same conditions, the plain-weave alginate oleogel fabric only reaches 62.5℃. This demonstrates the excellent temperature-raising performance of the honeycomb-shaped alginate oleogel fabric. It also indicates that the honeycomb-shaped alginate oleogel fabric has excellent photothermal properties and is suitable for atmospheric water collection.

[0084] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method for preparing an alginate oleogloss fabric for atmospheric water collection, characterized in that, The steps are as follows: (1) Sodium alginate and photothermal conversion material are added to deionized water and stirred to obtain a spinning solution containing sodium alginate; the spinning solution containing sodium alginate is extruded into calcium chloride solution to undergo a cross-linking reaction; the gel fiber obtained after the reaction is taken out and washed with deionized water to obtain fibrous alginate hydrogel. (2) Based on the fibrous alginate hydrogel obtained in step (1), fibrous alginate oleogel is prepared by immersing it in a polyol for displacement; the polyol is any one or more of glycerol, propylene glycol, and butylene glycol. (3) Based on the fibrous alginate oleogel obtained in step (2), honeycomb alginate oleogel fabric is prepared using a loom.

2. The method for preparing the alginate oleogel fabric for atmospheric water collection according to claim 1, characterized in that, The mass ratio of sodium alginate:photothermal conversion material:water in the spinning solution is 2~8:0.2~0.8:100; the concentration of calcium chloride solution should be 2 wt%~8 wt%.

3. The method for preparing the alginate oleogel 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 the alginate oleogel fabric for atmospheric water collection according to claim 1, characterized in that, The reaction conditions in step (1) are: temperature of 5℃~75℃ and time of 5-60 min.

5. The method for preparing the alginate oleogel fabric for atmospheric water collection according to claim 1, characterized in that, Step (2) specifically includes the following steps: Alginate hydrogel fibers are immersed in polyol for displacement, then removed and dried to obtain alginate oleogel fibers.

6. The method for preparing the alginate oleogel fabric for atmospheric water collection according to claim 5, characterized in that, In step (2), the bath ratio of the alginate hydrogel to the polyol is 1 g: 10~100 mL.

7. The method for preparing the alginate oleogel fabric for atmospheric water collection according to claim 5, characterized in that, The replacement time between the alginate hydrogel and the polyol in step (2) is more than 10 hours.

8. The method for preparing the alginate oleogel fabric for atmospheric water collection according to claim 1, characterized in that, Step (3) specifically includes the following steps: Alginic acid oleogel fibers are woven into a honeycomb structure on a loom to obtain an alginate oleogel fabric for atmospheric water collection.

9. An alginate oleogel fabric for atmospheric water collection prepared by the method of any one of claims 1-8.

10. The application of the alginate oleogel fabric for atmospheric water collection as described in claim 9 in water collection, soft materials, flexible electronics, sensors, wearable devices, and biomedicine.

Images