A preparation method of a compound light-heat interface evaporator

Abstract

The application relates to the technical field of material preparation, and discloses a preparation method of a compound light-heat interface evaporator. The compound light-heat interface evaporator prepared by the application is composed of a nanometer carbon tube deposition layer used as an upper light absorption layer and an attapulgite composite hydrogel layer used as a lower water transmission layer. Homogeneous non-woven fabrics with different thicknesses are selected to serve as three-dimensional network supports for the nanometer carbon tube deposition and the attapulgite hydrogel. The compound light-heat interface evaporator prepared by the application can achieve high weather resistance such as ultraviolet resistance and high-temperature resistance, and can work for a long time in a high-temperature and high-humidity environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of material preparation, in particular to a preparation method of a compound light-heat interface evaporator. BACKGROUND

[0002] Water resources, as an indispensable basic resource for human society, affect people's lives, economy and social development. However, with the continuous growth of global population and rapid economic development, water resources are facing increasing pressure. In addition, pollution of natural water sources, climate change and overexploitation of groundwater have also had a great impact on water resources.

[0003] In order to effectively address water resource problems, the development of technology and science has an important influence on the solution of water resource problems. Solar-driven interfacial light-heat conversion water evaporation, including evaporation of seawater, lake water or river water, has been considered as an environmentally friendly process to obtain clean water at low cost. However, water transportation itself is limited by the solar energy absorption capacity, especially for limited evaporation rate and insufficient working life. Therefore, it is of great significance to find light-heat conversion materials that can effectively absorb solar energy and rationally design solar-driven interfacial light-heat conversion water evaporation devices that can be used for a long time.

[0004] Hydrogels have been widely used in various fields such as drug delivery, tissue engineering, flexible electronics and seawater desalination due to their unique three-dimensional cross-linked polymer network structure, more hydrophilic groups, and better water absorption and retention capacity. Liu et al. prepared a flower-inspired biomimetic sodium alginate hydrogel evaporator with an evaporation rate of up to 3.2 kg / (m 2 ·h) (Carbohydrate Polymers, 2021, 118536). Li et al. prepared a porous polyvinyl alcohol biochar hydrogel evaporator that induces high-yield solar steam generation and sustainable seawater desalination (Journal of Environmental Chemical Engineering, 2022, 107690), with an evaporation rate of up to 1.89 kg / (m 2 ·h). Gao et al. prepared a simple and controllable black hydrogel coating strategy to prepare a self-cleaning durable evaporator for efficient solar steam generation (Desalination, 2023, 116341), with an evaporation rate of up to about 3 kg / (m 2 ·h). However, the working life problem of the interfacial light-heat conversion water evaporation device has not been effectively solved. SUMMARY

[0005] Invention purposes: In view of the problems in the prior art, the application provides a preparation method of a complex photothermal interface evaporator, the complex photothermal interface evaporator prepared by the application is composed of a nanometer carbon tube deposition layer used as an upper light absorption layer and an attapulgite composite hydrogel layer used as a lower water transmission layer, and the same non-woven fabric with different thicknesses is selected to serve as a three-dimensional network support for nanometer carbon tube deposition and attapulgite hydrogel, so that high weather resistance such as ultraviolet resistance and high temperature resistance can be achieved, and long-term work in a high temperature and high humidity environment can be achieved.

[0006] Technical scheme: The application provides a complex photothermal interface evaporator, which comprises a nanometer carbon tube deposition layer and an attapulgite composite hydrogel layer from top to bottom, and the nanometer carbon tube deposition layer and the attapulgite composite hydrogel layer both take non-woven fabric as a skeleton.

[0007] The nanometer carbon tube deposition layer is a photothermal conversion layer for light absorption, and the attapulgite composite hydrogel layer is an attapulgite-non-woven fabric composite hydrogel layer for water transmission.

[0008] Further, the pore size of the attapulgite composite hydrogel layer is 400 nm-200 mu m, the non-woven fabric in the nanometer carbon tube deposition layer has a specification of 10-100 g / m 2 , and the non-woven fabric in the attapulgite composite hydrogel layer has a specification of 100-500 g / m 2 .

[0009] The application further provides a preparation method of the complex photothermal interface evaporator, comprising the following steps:

[0010] S1. Carbon nanotubes, a surfactant and plant fibers are added to deionized water and ultrasonic dispersion is performed to obtain a mixed solution, then materials in the mixed solution are deposited on non-woven fabric by suction filtration, and an ethanol solution is added to perform suction filtration again, and drying is performed to obtain a nanometer carbon tube deposition layer;

[0011] S2. Clay and a sodium alginate solution are uniformly mixed, then a gluconolactone solution is added and uniformly mixed to obtain a sol, non-woven fabric is immersed in the sol, is flattened after sufficient soaking, and is suspended and scraped to remove excess sol, and is left to stand and age to form an attapulgite composite hydrogel layer; in the later stage of aging, the nanometer carbon tube deposition layer obtained in S1 is attached to the upper surface of the attapulgite composite hydrogel layer, and further aging and heating are performed to obtain the complex photothermal interface evaporator.

[0012] Further, in S1, the carbon nanotubes are one of hydroxylated carbon nanotubes and carboxylated carbon nanotubes;

[0013] In S1, the surfactant is one of sodium lauryl ether sulfate, sodium dodecyl benzene sulfonate and sodium dodecyl sulfate;

[0014] In S1, the plant fiber is one of bamboo fiber, hemp fiber, wood fiber or a combination of two or more thereof.

[0015] Further, in S1, the mass ratio of the carbon nanotube to the plant fiber is 1:0-0.2.

[0016] Further, in S2, the clay is one of attapulgite, sepiolite or other fibrous clay or a combination of two or more thereof.

[0017] Further, in S2, the concentration of the clay in the sol is 1-5 wt%. By controlling the concentration of the clay in the sol, the pore size of the hydrogel layer can be regulated to be between 400 nm and 200 μm.

[0018] Further, in S1, the non-woven fabric is one of polyester, polypropylene, polyamide and acrylic fiber; and the specification of the non-woven fabric in S1 is 10-100 g / m 2 .

[0019] Further, in S2, the non-woven fabric is one of polyester, polypropylene, polyamide and acrylic fiber; and the specification of the non-woven fabric in S2 is 100-500 g / m 2 .

[0020] Preferably, in S2, the specific conditions of the heating are that the heating time is 5-20 min and the heating temperature is 100-200℃.

[0021] Beneficial effects: Compared with the prior art, the compound photothermal interface evaporator provided by the application has a double-layer structure: the nanometer carbon tube deposition layer for light absorption can effectively convert light energy into heat energy for water evaporation; the attapulgite composite hydrogel layer for water transmission utilizes the capillary action of the micro-nano scale pores to quickly transport water to the light absorption layer; the same non-woven fabric with different thicknesses is selected to make the three-dimensional network support of the nanometer carbon tube deposition and the attapulgite hydrogel, and the same non-woven fabric is conducive to the close fitting between the layers, and the non-woven fabric as the skeleton can improve the mechanical strength of the nanometer carbon tube deposition layer.

[0022] The non-woven fabric in the attapulgite composite hydrogel layer has the characteristics of air permeability, flexibility, lightness, flame retardancy and recyclability, and also has a good pore structure, the addition of attapulgite regulates the pore size of the hydrogel and increases the hydrophilicity of the evaporator, which is more conducive to water transmission; the attapulgite composite hydrogel layer with the non-woven fabric as the skeleton has high mechanical strength and can work without shrinking and deforming in a long-term high-temperature and high-humidity environment, and shows good structural stability.

[0023] The compound photothermal interface evaporator prepared by the application has stable performance structure, high mechanical strength, no shrinking in use and can work in a long-term high-temperature and high-humidity environment. The water evaporation efficiency of one sun is 3 kg / (m2 It has a capacity of approximately 1.2 h and can be used in fields such as seawater desalination, wastewater treatment, and brine concentration. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure and evaporation device of the duplex photothermal interface evaporator prepared according to the present invention;

[0025] Figure 2 The curves showing the change of water mass over time under a certain solar radiation intensity during evaporation in the compound photothermal interface evaporator prepared according to embodiments 1-4 of the present invention;

[0026] Figure 3 The diagram shows the evaporation rate of the compound photothermal interface evaporator prepared in Embodiment 4 of the present invention after 15 days of circulation under one solar radiation intensity, as well as the shrinkage of the compound photothermal interface evaporator before and after use. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the embodiments.

[0028] Implementation method 1:

[0029] (1) Add 0.05g of carboxylated carbon nanotubes, 0.5g of bamboo fiber pulp (2 wt%) and 0.01g of sodium lauryl ether sulfate to 10ml of deionized water, and stir ultrasonically to completely disperse the carbon nanotubes; filter the mixed solution to deposit the carbon nanotubes on the nonwoven fabric, add ethanol solution and filter again, and dry to obtain the photothermal conversion layer carbon nanotube deposition layer for light absorption;

[0030] (2) Disperse 5g of attapulgite and 0.5g of sodium alginate powder in 100ml of deionized water, add 0.3g of glucono-delta-lactone and stir to mix the materials evenly to obtain a sol; immerse the nonwoven fabric in the mixed sol, and after fully wetting, flatten and scrape off the excess attapulgite hydrogel, and let it stand for aging; in the middle and late stage of gel aging, attach the carbon nanotube deposition layer in step (1) to the upper surface of the attapulgite-nonwoven fabric composite hydrogel layer, and further age to obtain a duplex photothermal interface evaporator.

[0031] The water evaporation rate of this dual-mode photothermal interface evaporator is 2.92 kg / (m³) under one solar radiation intensity. 2 ·h).

[0032] Implementation Method 2:

[0033] (1) 0.05 g carboxylated carbon nanotubes, 0.5 g bamboo fiber pulp (2 wt%) were added into 10 ml deionized water, and the carbon nanotubes were completely dispersed by ultrasonic stirring; the mixed solution was subjected to suction filtration to deposit the carbon nanotubes on the non-woven fabric, and an ethanol solution was added again for suction filtration, and drying to obtain a nanocarbon tube deposition layer for light absorption of the light-heat conversion layer;

[0034] (2) 5 g attapulgite and 0.5 g sodium alginate powder were dispersed in 100 ml deionized water, 0.3 g gluconolactone was added and the materials were stirred to mix uniformly to obtain a sol; the non-woven fabric was immersed in the mixed sol, and after sufficient soaking, it was flattened and the excess attapulgite hydrogel was scraped off, and it was left to stand and age; in the later stage of gel aging, the nanocarbon tube deposition layer in step (1) was attached to the upper surface of the attapulgite-non-woven fabric composite hydrogel layer, and further aging was carried out, and it was placed on a heating table at 150°C for 10 minutes to obtain a composite light-heat interface evaporator.

[0035] The water evaporation rate of the composite light-heat interface evaporator under one solar light intensity is 2.46 kg / (m 2 ·h).

[0036] Embodiment 3:

[0037] (1) 0.05 g carboxylated carbon nanotubes, 0.5 g bamboo fiber pulp (2 wt%) were added into 10 ml deionized water, and the carbon nanotubes were completely dispersed by ultrasonic stirring; the mixed solution was subjected to suction filtration to deposit the carbon nanotubes on the non-woven fabric, and an ethanol solution was added again for suction filtration, and drying to obtain a nanocarbon tube deposition layer for light absorption of the light-heat conversion layer;

[0038] (2) 5 g attapulgite and 0.5 g sodium alginate powder were dispersed in 100 ml deionized water, 0.3 g gluconolactone was added and the materials were stirred to mix uniformly to obtain a sol; the non-woven fabric was immersed in the mixed sol, and after sufficient soaking, it was flattened and the excess attapulgite hydrogel was scraped off, and it was left to stand and age; in the later stage of gel aging, the nanocarbon tube deposition layer in step (1) was attached to the upper surface of the attapulgite-non-woven fabric composite hydrogel layer, and further aging was carried out, and it was placed on a heating table at 150°C for 10 minutes to obtain a composite light-heat interface evaporator.

[0039] The water evaporation rate of the composite light-heat interface evaporator under one solar light intensity is 2.46 kg / (m 2 ·h).

[0040] Embodiment 4:

[0041] (1) 0.05 g of hydroxylated carbon nanotubes, 0.5 g of bamboo fiber slurry (2 wt%) and 0.01 g of sodium lauryl ether sulfate were added to 10 ml of deionized water, and the carbon nanotubes were completely dispersed by ultrasonic stirring; the mixed solution was subjected to suction filtration to deposit the carbon nanotubes on the non-woven fabric, and an ethanol solution was added again for suction filtration, and drying to obtain a nano-carbon tube deposition layer for light absorption and light-heat conversion layer;

[0042] (2) 5 g of attapulgite and 0.5 g of sodium alginate powder were dispersed in 100 ml of deionized water, 0.3 g of gluconolactone was added and the material was stirred to mix uniformly to obtain a sol; the non-woven fabric was immersed in the mixed sol, fully soaked, flattened and suspended to scrape off the excess attapulgite hydrogel, and aged; in the later stage of gel aging, the nano-carbon tube deposition layer in step (1) was attached to the upper surface of the attapulgite-non-woven fabric composite hydrogel layer, further aged, and placed on a heating table at 180°C for 5 minutes to obtain the said composite light-heat interface evaporator.

[0043] The water evaporation rate of the composite light-heat interface evaporator under a solar light intensity of 1 sun is 3.05 kg / (m 2 ·h).

[0044] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. A method of preparing a compound photothermal interface evaporator, characterized in that, The method comprises the following steps: S1. adding carbon nanotubes, a surfactant and plant fibers into deionized water and performing ultrasonic dispersion to obtain a mixed solution, then depositing the materials in the mixed solution on a non-woven fabric by suction filtration, adding an ethanol solution and performing suction filtration again, drying to obtain a carbon nanotube deposition layer; S2. uniformly mixing attapulgite and a sodium alginate solution, then adding a gluconolactone solution and uniformly mixing again to obtain a sol; immersing the non-woven fabric in the sol, flattening after sufficient soaking, suspending and scraping off the excess sol, standing and aging to form an attapulgite composite hydrogel layer; in the later stage of aging, attaching the carbon nanotube deposition layer obtained in S1 to the upper surface of the attapulgite composite hydrogel layer, further aging and heating to obtain the composite photothermal interface evaporator; The composite photothermal interface evaporator comprises, from top to bottom, a carbon nanotube deposition layer and an attapulgite composite hydrogel layer, and the carbon nanotube deposition layer and the attapulgite composite hydrogel layer both take a non-woven fabric as a skeleton.

2. The method of claim 1, wherein: The pore size of the attapulgite composite hydrogel layer is 400 nm-200 μm; the non-woven fabric specification in the nanometer carbon tube deposition layer is 10-100 g / m 2 ; the non-woven fabric specification in the attapulgite composite hydrogel layer is 100-500 g / m 2 .

3. The method of claim 1, wherein: In S1, the carbon nanotubes are one of hydroxylated carbon nanotubes and carboxylated carbon nanotubes. In S1, the surfactant is one of sodium lauryl ether sulfate, sodium dodecyl benzene sulfonate and sodium dodecyl sulfate. In S1, the plant fibers are one or a combination of two or more of bamboo fibers, hemp fibers and wood fibers.

4. The method of claim 1, wherein: In S1, the mass ratio of the carbon nanotubes to the plant fibers is 1:0-0.

2.

5. The method of claim 1, wherein: In S2, the concentration of attapulgite in the sol is 1-5 wt%.

6. The method of claim 1, wherein: In S1, the non-woven fabric is one of polyester, polypropylene, polyamide, and acrylic. In S1, the non-woven fabric has a specification of 10-100 g / m 2 .

7. The method of claim 1, wherein: In S2, the non-woven fabric is one of polyester, polypropylene, polyamide, and acrylic. In S2, the non-woven fabric has a specification of 100-500 g / m 2 .

8. The method of claim 1-7, wherein: In S2, the specific conditions of the heating are that the heating time is 5-20 min and the heating temperature is 100-200℃.

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