Low-fluid-resistance three-dimensional material with vertical pore structure as well as preparation method and application of low-fluid-resistance three-dimensional material

Abstract

The invention discloses a low-fluid-resistance three-dimensional material with a vertical pore structure as well as a preparation method and application of the low-fluid-resistance three-dimensional material. The low-fluid-resistance three-dimensional material comprises a hydrophilic liquid absorption core, a low-fluid-resistance vertical hole polymer sleeve and a photoelectric composite functional layer from inside to outside. The preparation method comprises the following steps: standing a micro-crosslinked polymer solution in a mold with a vertical pore structure, and drying to obtain a hydrophilic wick; a polymer solution containing carboxyl groups is poured on the outer layer of the hydrophilic wick, a low-fluid-resistance vertical-hole polymer sleeve is obtained after freezing and saline soaking, then a low-crystal metal organic framework and copper sulfide particles grow in situ, and the photoelectric composite functional layer is obtained. The low-fluid-resistance three-dimensional material prepared by the method has excellent photo-thermal conversion capability and electrothermal characteristics, multi-layer advantage complementation and multifunctional coupling are realized, and the high-performance low-fluid-resistance three-dimensional material is finally obtained and can be used for realizing efficient thermal management, especially all-weather photo-thermal-electrothermal seawater desalination.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a low fluid resistance three-dimensional material with a vertical pore structure, its preparation method, and its application. Background Technology

[0002] Solar energy is a renewable energy source, and solar thermal desalination is an important way to solve the shortage of freshwater resources. However, solar thermal desalination still faces several prominent problems: there is a heat and mass balance between water supply and solar thermal evaporation. If the supply exceeds the evaporation or vice versa, heat loss will occur, reducing the photothermal conversion efficiency. Moreover, during the solar thermal desalination process, inorganic salts are prone to crystallization and accumulation on the surface and inside the evaporator, hindering water transport, reducing photothermal conversion efficiency, and lowering the water evaporation rate. The performance of solar thermal evaporation is positively correlated with light intensity. A decrease in light intensity leads to a decrease in solar thermal evaporation capacity, and water evaporation is difficult to achieve at night when there is no sunlight. Summary of the Invention

[0003] The main objective of this invention is to provide a low fluid resistance three-dimensional material with a vertical pore structure and its preparation method, so as to overcome the shortcomings of the prior art.

[0004] Another object of the present invention is to provide applications of the aforementioned low fluid resistance three-dimensional material with a vertical pore structure.

[0005] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0006] This invention provides a method for preparing a low-fluid-resistance three-dimensional material with a vertical pore structure, comprising:

[0007] (1) Mix agar, organic matter, water and additives evenly to form a micro-crosslinked polymer solution; let the micro-crosslinked polymer solution stand in a mold with a vertical pore structure and dry to obtain a hydrophilic absorbent core;

[0008] (2) Mix the polymer, polyacrylic acid, small molecule base and organic solvent uniformly to form a polymer solution, and then place the polymer solution in the mold containing the hydrophilic absorbent core obtained in step (1) and freeze it to form a low fluid resistance vertical hole polymer sleeve on the local surface of the hydrophilic absorbent core.

[0009] (3) Apply a first mixed aqueous solution containing metal salt and organic acid to the low fluid resistance vertical hole polymer sleeve with hydrophilic liquid-absorbing core prepared in step (2) and carry out the first reaction. Then, immerse it in 2-methylpyrazole aqueous solution to carry out the second reaction, thereby growing a low crystal metal-organic framework transition layer in situ on the surface of the low fluid resistance vertical hole polymer sleeve.

[0010] (4) Copper sulfide particles are grown in situ on the surface of the low-crystal metal-organic framework transition layer obtained in step (3) to form a photoelectric composite functional layer, thereby obtaining a three-dimensional material with low fluid resistance and vertical pore structure.

[0011] In some embodiments, step (4) includes: immersing the composite material obtained in step (3) in a second mixed aqueous solution containing copper salt and conductive material, maintaining it at 10-40°C for 5 min-24 h, and then immersing it in an ammonium sulfide solution for 30 s-1 h, thereby growing copper sulfide particles in situ on the surface of the low-crystal metal-organic framework transition layer.

[0012] This invention also provides a low fluid resistance three-dimensional material with a vertical pore structure prepared by the aforementioned method.

[0013] In some embodiments, the low fluid resistance three-dimensional material includes, from the inside out, a hydrophilic absorbent core, a low fluid resistance vertical hole polymer sleeve, and a photoelectric composite functional layer. The photoelectric composite functional layer includes a low-crystalline metal-organic framework transition layer and copper sulfide particles distributed on the surface of the low-crystalline metal-organic framework transition layer. The low fluid resistance vertical hole polymer sleeve is fitted onto a local surface of the hydrophilic absorbent core, and the photoelectric composite functional layer is coated on the surface of the low fluid resistance vertical hole polymer sleeve.

[0014] This invention also provides the application of the aforementioned low fluid resistance three-dimensional material with vertical pore structure in the field of photothermal-electrothermal seawater desalination.

[0015] Compared with the prior art, the beneficial effects of the present invention include:

[0016] 1) In the low fluid resistance three-dimensional material with vertical pore structure prepared by this invention, the hydrophilic liquid-absorbing core and the low fluid resistance vertical pore polymer sleeve can jointly regulate the water supply rate and maintain heat-mass balance to achieve efficient photothermal water evaporation; the vertically structured polymer sleeve can inhibit the precipitation and deposition of inorganic salt crystals on the surface and inside the pores of the photoelectric composite functional layer, ensuring water supply and water vapor overflow, and improving the photothermal and electrothermal water evaporation performance; the photoelectric composite functional layer has excellent photothermal conversion ability and electrothermal characteristics, realizing rapid water evaporation in all weather conditions, breaking the influence of day-night alternation on conventional photothermal water evaporation;

[0017] 2) The low fluid resistance three-dimensional material with vertical pore structure prepared by this invention has multiple complementary advantages and multifunctional coupling, and finally obtains a high-performance low fluid resistance three-dimensional material, which can be used to realize efficient thermal management, especially all-weather photothermal-electrical desalination of seawater. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a low fluid resistance three-dimensional material with a vertical hole structure in a typical embodiment of the present invention;

[0020] Figure 2 This is a photograph of the hydrophilic liquid-absorbing core prepared in Example 4 of the present invention;

[0021] Figure 3 This is a cross-sectional SEM image of the vertical hole structure sleeve prepared in Embodiment 4 of the present invention;

[0022] Figure 4 This is a surface SEM image of the optoelectronic composite functional layer prepared in Example 4 of the present invention.

[0023] Figure reference numerals: 1-hydrophilic absorbent core, 2-low fluid resistance vertical pore polymer sleeve, 3-photoelectric composite functional layer. Detailed Implementation

[0024] In view of the problems existing in the prior art, after long-term research and a large number of experiments, the inventor of this case proposed the technical solution, which mainly provides a low fluid resistance three-dimensional material with a vertical hole structure. The three-dimensional material includes a hydrophilic liquid-absorbing core from the inside out, a low fluid resistance vertical hole polymer sleeve, and a photoelectric composite functional layer.

[0025] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0026] As one aspect of the technical solution of this invention, it relates to a method for preparing a low fluid resistance three-dimensional material with a vertical pore structure, which mainly involves: casting a micro-crosslinked agar-based polymer solution into a copper tube and drying it to obtain a hydrophilic absorbent core; casting a polymer solution containing carboxyl groups onto the outer layer of the hydrophilic absorbent core, and obtaining a polymer sleeve with a vertical pore structure after freezing and soaking in brine; and growing a low-crystallinity metal-organic framework and copper sulfide particles in situ to obtain a photoelectric composite functional layer.

[0027] In some specific embodiments, the method for preparing the low fluid resistance three-dimensional material with a vertical pore structure includes the following steps:

[0028] (1) Mix agar, organic matter, water and additives evenly to form a micro-crosslinked polymer solution; let the micro-crosslinked polymer solution stand in a mold with a vertical pore structure and dry to obtain a hydrophilic absorbent core;

[0029] (2) Mix the polymer, polyacrylic acid, small molecule base and organic solvent uniformly to form a polymer solution, and then place the polymer solution in the mold containing the hydrophilic absorbent core obtained in step (1) and freeze it to form a low fluid resistance vertical hole polymer sleeve on the local surface of the hydrophilic absorbent core.

[0030] (3) Apply a first mixed aqueous solution containing metal salt and organic acid to the low fluid resistance vertical hole polymer sleeve with hydrophilic liquid-absorbing core prepared in step (2) and carry out the first reaction. Then, immerse it in 2-methylpyrazole aqueous solution to carry out the second reaction, thereby growing a low crystal metal-organic framework transition layer in situ on the surface of the low fluid resistance vertical hole polymer sleeve.

[0031] (4) Copper sulfide particles are grown in situ on the surface of the low-crystal metal-organic framework transition layer obtained in step (3) to form a photoelectric composite functional layer, thereby obtaining a three-dimensional material with low fluid resistance and vertical pore structure.

[0032] In some implementations, step (1) specifically includes: adding agar and organic matter to water and stirring to dissolve them, then adjusting the pH value to 1-5, and then adding additives to obtain the micro-crosslinked polymer solution.

[0033] In some implementations, in step (1), the organic material includes any one or a combination of two or more of polyvinyl alcohol, sodium alginate, chitosan, etc., but is not limited to this.

[0034] In some implementations, in step (1), the additive includes any one or a combination of two or more of glutaraldehyde, glycerol, sorbitol, etc., but is not limited to this.

[0035] In some embodiments, in step (1), the agar content in the micro-crosslinked polymer solution is 0.5–8 wt%.

[0036] In some embodiments, in step (1), the organic content in the micro-crosslinked polymer solution is 0.5–10 wt%.

[0037] In some embodiments, in step (1), the content of the additive in the micro-crosslinked polymer solution is 0.1–5 wt%.

[0038] In some implementations, in step (1), the temperature for settling is 10 to 60°C, and the settling time is 5 min to 2 h.

[0039] In some implementations, in step (1), the temperature for stirring and dissolving is 10 to 100°C, and the stirring and dissolving time is 0.5 to 8 hours.

[0040] Further, step (1) specifically includes: adding hydrochloric acid to adjust the pH value to 1-5.

[0041] In some implementations, step (2) specifically includes: adding the polymer, polyacrylic acid and small molecule base to an organic solvent, stirring to dissolve, and obtaining a polymer solution; then placing the polymer solution in a mold containing a hydrophilic absorbent core obtained in step (1) and freezing it, then removing it and immersing it in brine to remove the mold.

[0042] In some embodiments, in step (2), the polymer includes any one or more combinations of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polysulfone, etc., but is not limited thereto.

[0043] In some implementations, in step (2), the small molecule base includes any one or a combination of two or more of ammonia, urea, triethylamine, etc., but is not limited to this.

[0044] In some embodiments, in step (2), the organic solvent includes any one or a combination of two or more of dimethyl sulfone, dimethyl sulfoxide, N-methylpyrrolidone, etc., but is not limited thereto.

[0045] In some embodiments, in step (2), the polymer content in the polymer solution is 2-30 wt%.

[0046] In some embodiments, in step (2), the content of polyacrylic acid in the polymer solution is 1 to 10 wt%.

[0047] In some embodiments, in step (2), the content of small molecule base in the polymer solution is 0.1–5 wt%.

[0048] In some implementations, in step (2), the freezing temperature is -60 to 0°C and the freezing time is 1 to 24 hours.

[0049] In some implementations, in step (2), the temperature for stirring and dissolving is 10–120°C, and the stirring and dissolving time is 0.5–24 h.

[0050] Furthermore, the salt concentration used in step (2) is 1–30 wt%.

[0051] In some embodiments, step (3) specifically includes: pouring a first mixed aqueous solution containing metal salt and organic acid onto the low fluid resistance vertical hole polymer sleeve with hydrophilic absorbent core prepared in step (2), performing a first reaction at 10-100°C for 0.5-24 h, and then immersing it in a 2-methylpyrazole aqueous solution for a second reaction at 10-100°C for 10 s-24 h, thereby growing a low-crystallinity metal-organic framework transition layer in situ on the surface of the low fluid resistance vertical hole polymer sleeve.

[0052] In some implementations, in step (3), the metal salt is an iron salt, which may include any one or a combination of two or more of ferric chloride, ferric nitrate, ferric sulfate, etc., but is not limited to this.

[0053] In some implementations, in step (3), the organic acid includes any one or a combination of two or more of fumaric acid, acetic acid, 2-aminoterephthalic acid, etc., but is not limited to this.

[0054] In some embodiments, in step (3), the content of the metal salt in the first mixed aqueous solution is 0.5 to 5 wt%.

[0055] In some implementations, in step (3), the content of organic acid in the first mixed aqueous solution is 0.1 to 15 wt%.

[0056] In some embodiments, in step (3), the concentration of the 2-methylpyrazole aqueous solution is 0.01–10 wt%.

[0057] In some embodiments, step (4) specifically includes: immersing the composite material obtained in step (3) into a second mixed aqueous solution containing copper salt and conductive material, and maintaining it at 10-40°C for 5 min-24 h, and then immersing it in an ammonium sulfide solution for 30 s-1 h, thereby growing copper sulfide particles in situ on the surface of the low-crystal metal-organic framework transition layer.

[0058] In some implementations, in step (4), the copper salt includes any one or a combination of two or more of copper nitrate, copper chloride, copper sulfate, etc., but is not limited to this.

[0059] In some implementations, in step (4), the conductive material includes any one or a combination of two or more of carbon nanotubes, polypyrrole particles, Mxene nanosheets, etc., but is not limited to this.

[0060] In some embodiments, in step (4), the content of copper salt in the second mixed aqueous solution is 2 to 20 wt%.

[0061] In some embodiments, in step (4), the content of conductive material in the second mixed aqueous solution is 0.01 to 2 wt%.

[0062] In some embodiments, in step (4), the concentration of the ammonium sulfide solution is 2–14 wt%.

[0063] As one more specific implementation, the method for preparing the low fluid resistance three-dimensional material with a vertical pore structure may include the following steps:

[0064] (1) Add 0.5-8 wt% agar and 0.5-10 wt% organic matter to water, stir and dissolve at 10-100℃ for 0.5-8h, add hydrochloric acid to adjust the pH to 1-5, and then add 0.1-5 wt% additive to obtain a micro-crosslinked polymer solution; then transfer it into a copper tube, let it stand at 10-60℃ for 5min-2h, and dry it to obtain a hydrophilic absorbent core;

[0065] (2) Add 2-30 wt% polymer, 1-10 wt% polyacrylic acid and 0.1-5 wt% small molecule base to an organic solvent, stir and dissolve at 10-120°C for 0.5-24 h to obtain a polymer solution; then transfer it into the copper tube containing the hydrophilic absorbent core in step (1), freeze at -60-0°C for 1-24 h, take it out and soak it in 1-30 wt% salt water to remove the copper tube, thereby obtaining a sleeve with a low fluid resistance vertical hole structure coated on the outer surface of the hydrophilic absorbent core;

[0066] (3) A mixed aqueous solution consisting of 0.5-5 wt% metal salt and 0.1-15 wt% organic acid is poured onto the hydrophilic absorbent core / low fluid resistance vertical hole sleeve prepared in step (2), and reacted at 10-100℃ for 0.5-24h. After being taken out, it is immersed in a 2-methylpyrazole aqueous solution with a concentration of 0.01-10 wt%, and stirred at 10-100℃ for 10s-24h, thereby growing a low-crystallinity metal-organic framework transition layer in situ on the low fluid resistance vertical hole sleeve;

[0067] (4) The three-dimensional material prepared in step (3) is immersed in a mixed aqueous solution of 2-20 wt% copper salt and 0.01-2 wt% conductive material and kept at 10-40°C for 5 min-24 h. Then it is immersed in 2-14 wt% ammonium sulfide solution for 30 s-1 h. Copper sulfide particles are grown in situ on the low crystallinity metal-organic framework. The two form a photoelectric composite functional layer to obtain the three-dimensional material with low fluid resistance and vertical pore structure.

[0068] As another aspect of the technical solution of the present invention, it also relates to a low fluid resistance three-dimensional material with a vertical pore structure prepared by the aforementioned method.

[0069] In some implementation schemes, please refer to Figure 1 As shown, the low fluid resistance three-dimensional material with a vertical hole structure includes a hydrophilic absorbent core 1, a low fluid resistance vertical hole polymer sleeve 2, and a photoelectric composite functional layer 3 arranged sequentially from the inside out. The low fluid resistance vertical hole polymer sleeve 2 is sleeved on a local surface of the hydrophilic absorbent core 1, and the photoelectric composite functional layer 3 is covered on the surface of the low fluid resistance vertical hole polymer sleeve 2.

[0070] Specifically, the working mechanism of each layer in the low fluid resistance three-dimensional material with vertical hole structure of the present invention is as follows:

[0071] 1. The hydrophilic liquid-absorbing core is in direct contact with the water body, absorbing water into the evaporator (i.e., a low fluid resistance three-dimensional bulk material) and working together with the low fluid resistance vertical hole polymer sleeve to regulate the water supply rate and maintain heat-mass balance to achieve efficient photothermal evaporation.

[0072] 2. The low fluid resistance vertical hole polymer sleeve inhibits the precipitation and deposition of inorganic salt crystals on the surface and inside the pores of the photoelectric composite functional layer, ensuring water supply and water vapor overflow, and improving the evaporation performance of photothermal and electric hot water.

[0073] In some embodiments, the optoelectronic composite functional layer includes a low-crystalline metal-organic framework transition layer and copper sulfide particles distributed on the surface of the low-crystalline metal-organic framework transition layer. The optoelectronic composite functional layer possesses excellent photothermal conversion capabilities and electrothermal properties, enabling rapid water evaporation in all weather conditions and overcoming the influence of day-night alternation on conventional photothermal water evaporation.

[0074] Therefore, by combining the advantages of multiple layers and coupling multiple functions, a high-performance, low-fluid-resistance three-dimensional material is finally obtained, which can be used to achieve efficient thermal management, especially all-weather photothermal-electrical desalination of seawater.

[0075] Furthermore, the ratio of the diameter or side length of the hydrophilic liquid-absorbing core, the thickness of the low fluid resistance vertical hole polymer sleeve, to the thickness of the photoelectric composite functional layer is 1-10:1-30:1-3.

[0076] Furthermore, the shape of the hydrophilic absorbent core can be cylindrical, square, or other shapes.

[0077] Furthermore, the thickness of the low-crystallinity metal-organic framework transition layer is 50 nm to 400 μm.

[0078] Furthermore, the particle size of the copper sulfide particles is 10 nm to 500 μm.

[0079] In some preferred embodiments, the low fluid resistance three-dimensional material is subjected to a flow rate of 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 5.2 kg / m³.-2 h -1 The seawater evaporation rate is 4.9 kg / m³. -2 h -1 The above; at night without light, with an applied voltage of 3V, the evaporation rate of pure water is 4.5 kg / m³. -2 h -1 The seawater evaporation rate is 4.2 kg / m³. -2 h -1 above.

[0080] In summary, the low-fluid-resistance three-dimensional material prepared by this invention has excellent photothermal conversion capability and electrothermal properties. The multi-layer complementary advantages and multi-functional coupling result in a high-performance, low-fluid-resistance three-dimensional material that can be used to achieve efficient thermal management, especially all-weather photothermal-electrothermal seawater desalination.

[0081] Another aspect of the present invention provides the application of the aforementioned low fluid resistance three-dimensional material with vertical hole structure. Specifically, the low fluid resistance three-dimensional material can be used in the field of thermal management, especially in the field of all-weather solar thermal-electric desalination.

[0082] The present invention will now be described in more detail with reference to embodiments and accompanying drawings, but the embodiments described do not constitute a limitation thereof. All modifications that are conceived of or derived from the content disclosed in this invention are considered to be within the scope of protection of this invention.

[0083] Example 1

[0084] (1) Add 8wt% agar and 10wt% polyvinyl alcohol to water, stir and dissolve at 100℃ for 0.5h, add hydrochloric acid to adjust the pH to 1, and then add 5wt% glutaraldehyde to obtain a micro-crosslinked polymer solution; then transfer it into a copper tube, let it stand at 10℃ for 5min, and dry it to obtain a hydrophilic liquid-absorbing core.

[0085] (2) Add 2wt% polyvinylidene fluoride, 10wt% polyacrylic acid and 0.1wt% ammonia to dimethyl sulfone, stir and dissolve at 120°C for 24h to obtain a polymer solution; then transfer it into the copper tube containing the hydrophilic absorbent core in step (1), freeze at 0°C for 1h, take it out and soak it in 1wt% salt water to remove the copper tube, and coat the surface of the hydrophilic absorbent core with a polymer sleeve with a low fluid resistance vertical hole structure.

[0086] (3) A mixed aqueous solution of 0.5wt% ferric chloride and 0.1wt% fumaric acid was poured onto the hydrophilic liquid-absorbing core / low fluid resistance vertical hole polymer sleeve prepared in step (2), and reacted at 10°C for 24h. After being taken out, it was immersed in a 0.01wt% 2-methylpyrazole aqueous solution and stirred at 10°C for 24h to grow a low crystallinity metal-organic framework transition layer in situ on the low fluid resistance vertical hole sleeve.

[0087] (4) The three-dimensional material prepared in step (3) is immersed in a mixed aqueous solution of 2wt% copper nitrate and 0.01wt% carbon nanotubes and kept at 10°C for 24h. Then it is immersed in 2% ammonium sulfide solution for 1h. Copper sulfide particles are grown in situ on the low crystal metal-organic framework. The two form a photoelectric composite functional layer to obtain a three-dimensional material with low fluid resistance and vertical pore structure.

[0088] The low fluid resistance three-dimensional material obtained in this embodiment was tested, and the results are as follows: 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 5.2 kg / m³. -2 h -1 The seawater evaporation rate is 4.9 kg m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 4.5 kg / m³. -2 h -1 The seawater evaporation rate is 4.2 kg / m³. -2 h -1 .

[0089] Example 2

[0090] (1) Add 0.5wt% agar and 0.5wt% sodium alginate to water, stir and dissolve at 10℃ for 8h, add hydrochloric acid to adjust the pH to 5, and then add 0.1wt% glycerol to obtain a micro-crosslinked polymer solution; then transfer it into a copper tube, let it stand at 60℃ for 2h, and dry it to obtain a hydrophilic liquid-absorbing core.

[0091] (2) Add 30wt% polyvinylidene fluoride-hexafluoropropylene copolymer, 1wt% polyacrylic acid and 5wt% urea to dimethyl sulfoxide, stir and dissolve at 80°C for 0.5h to obtain a polymer solution; then transfer it into the copper tube containing the hydrophilic absorbent core in step (1), freeze at -60°C for 24h, take it out and soak it in 30wt% brine to remove the copper tube, and coat the surface of the hydrophilic absorbent core with a polymer sleeve with a low fluid resistance vertical hole structure;

[0092] (3) A mixed aqueous solution of 5 wt% ferric nitrate and 15 wt% acetic acid was poured onto the hydrophilic liquid-absorbing core / low fluid resistance vertical hole polymer sleeve prepared in step (2), and reacted at 100°C for 0.5 h. After being taken out, it was immersed in a 10 wt% 2-methylpyrazole aqueous solution and stirred at 100°C for 10 s to grow a low crystallinity metal-organic framework transition layer in situ on the low fluid resistance vertical hole sleeve.

[0093] (4) The three-dimensional material prepared in step (3) is immersed in a mixed aqueous solution of 20 wt% copper chloride and 2 wt% polypyrrole particles, kept at 40°C for 5 min, and then immersed in 14 wt% ammonium sulfide solution for 30 s. Copper sulfide particles are grown in situ on the low crystal metal-organic framework. The two form a photoelectric composite functional layer to obtain a three-dimensional material with low fluid resistance and vertical pore structure.

[0094] The low fluid resistance three-dimensional material obtained in this embodiment was tested, and the results are as follows: 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 6.6 kg m³. -2 h -1 The seawater evaporation rate is 6.2 kg / m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 6.1 kg / m³. -2 h -1 The seawater evaporation rate is 5.8 kg / m³. -2 h -1 .

[0095] Example 3

[0096] (1) Add 2wt% agar and 2wt% chitosan to water, stir and dissolve at 90℃ for 5h, add hydrochloric acid to adjust the pH to 3, and then add 1wt% sorbitol to obtain a micro-crosslinked polymer solution; then transfer it into a copper tube, let it stand at 40℃ for 25min, and dry it to obtain a hydrophilic liquid-absorbing core.

[0097] (2) Add 15wt% polysulfone, 5wt% polyacrylic acid and 1wt% triethylamine to N-methylpyrrolidone, stir and dissolve at 10°C for 12h to obtain a polymer solution; then transfer it into the copper tube containing the hydrophilic absorbent core in step (1), freeze at -18°C for 10h, take it out and soak it in 20wt% salt water to remove the copper tube, and coat the outer surface of the hydrophilic absorbent core with a polymer sleeve with a low fluid resistance vertical hole structure.

[0098] (3) A mixed aqueous solution of 2wt% ferric sulfate and 2wt% 2-aminoterephthalic acid was poured onto the hydrophilic liquid-absorbing core / low fluid resistance vertical hole polymer sleeve prepared in step (2), and reacted at 50°C for 4 hours. After being taken out, it was immersed in a 1wt% 2-methylpyrazole aqueous solution and stirred at 20°C for 1 hour to grow a low-crystal metal-organic framework transition layer in situ on the low fluid resistance vertical hole sleeve.

[0099] (4) The three-dimensional material prepared in step (3) is immersed in a mixed aqueous solution of 5 wt% copper sulfate and 1 wt% Mxene nanosheets and kept at 30°C for 5 h. Then it is immersed in 6 wt% ammonium sulfide solution for 10 min. Copper sulfide particles are grown in situ on the low crystal metal-organic framework. The two form a photoelectric composite functional layer to obtain a three-dimensional material with low fluid resistance and vertical pore structure.

[0100] The low fluid resistance three-dimensional material obtained in this embodiment was tested, and the results are as follows: 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 6.3 kg / m³. -2 h -1 The seawater evaporation rate is 6.5 kg / m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 5.9 kg / m³. -2 h -1 The seawater evaporation rate is 5.6 kg / m³. -2 h -1 .

[0101] Example 4

[0102] (1) Add 1.5 wt% agar and 1.5 wt% polyvinyl alcohol to water, stir and dissolve at 90°C for 6 hours, add hydrochloric acid to adjust the pH to 2, and then add 3 wt% glutaraldehyde to obtain a micro-crosslinked polymer solution; then transfer it into a copper tube, let it stand at 15°C for 1 hour, and dry it to obtain a hydrophilic absorbent core. A photograph of the hydrophilic absorbent core is shown below. Figure 2 As shown;

[0103] (2) Add 5 wt% polyvinylidene fluoride-hexafluoropropylene copolymer, 5 wt% polyacrylic acid and 1 wt% ammonia to dimethyl sulfoxide, stir at 90°C for 6 h to dissolve, and obtain a polymer solution; then transfer it into the copper tube containing the hydrophilic absorbent core in step (1), freeze at -30°C for 8 h, take it out and soak it in 20 wt% brine to remove the copper tube, and coat the outer surface of the hydrophilic absorbent core with a polymer sleeve with a low fluid resistance vertical hole structure. The cross-sectional SEM image is shown below. Figure 3 As shown;

[0104] (3) A mixed aqueous solution of 3wt% ferric chloride and 3wt% 2-aminoterephthalic acid was poured onto the hydrophilic absorbent core / low fluid resistance vertical hole polymer sleeve prepared in step (2), and reacted at 50°C for 2h. After being taken out, it was immersed in a 2wt% 2-methylpyrazole aqueous solution and stirred at 60°C for 0.5h to grow a low crystallinity metal-organic framework transition layer in situ on the low fluid resistance vertical hole sleeve.

[0105] (4) The three-dimensional material prepared in step (3) is immersed in a mixed aqueous solution of 5 wt% copper nitrate and 1 wt% Mxene nanosheets and kept at 30°C for 1 h. Then it is immersed in a 10 wt% ammonium sulfide solution for 0.5 h. Copper sulfide particles are grown in situ on the low-crystallinity metal-organic framework. The two form a photoelectric composite functional layer, and a low fluid resistance three-dimensional material with a vertical pore structure is obtained. The surface SEM image of the photoelectric composite functional layer is shown below. Figure 4 As shown.

[0106] The low fluid resistance three-dimensional material obtained in this embodiment was tested, and the results are as follows: 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 7.2 kg / m³. -2 h -1 The seawater evaporation rate is 7.0 kg / m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 6.8 kg / m³. -2 h -1 The seawater evaporation rate is 6.4 kg / m³. -2 h -1 .

[0107] Compare with Example 1

[0108] This comparative example is basically the same as Example 4, except that a hydrophilic liquid-absorbing core is not constructed.

[0109] This invention relies on a hydrophilic absorbent core that directly contacts the water body to absorb water into the evaporator, thereby achieving photothermal evaporation. Without the hydrophilic absorbent core, photothermal evaporation cannot be achieved due to insufficient water supply.

[0110] Compare with Example 2

[0111] This comparative example is basically the same as Example 4, except that a sleeve with a vertical hole structure is not constructed. In this case, the photoelectric composite functional layer is in direct contact with the hydrophilic absorbent core, resulting in a large water supply and the formation of a thick water film on the surface of the photoelectric composite functional layer. This not only inhibits light absorption and photothermal conversion efficiency but also leads to significant heat loss through radiation and convection, resulting in reduced photothermal evaporation performance. The test results are as follows: 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 1.8 kg m³. -2 h -1 The seawater evaporation rate is 1.3 kg m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 0.9 kg / m³. -2 h -1 The seawater evaporation rate is 0.8 kg / m³. -2 h-1 .

[0112] Compare with Example 3

[0113] This comparative example is basically the same as Example 4, except that the prepared sleeve does not have a vertical hole structure. Therefore, during seawater evaporation, inorganic salts easily precipitate and deposit on the surface and inside the pores of the photoelectric composite functional layer, hindering water supply and water vapor overflow, resulting in reduced photothermal and electrothermal evaporation performance. The test results are as follows: 1000W / m 2 Under simulated continuous sunlight exposure for 4 hours, the evaporation rate of pure water is 6.9 kg m³. -2 h -1 The seawater evaporation rate is 6.5 kg / m³. -2 h -1 With the illumination time extended to 24 hours, the evaporation rate of pure water was 5.1 kg m³. -2 h -1 The seawater evaporation rate is 0.8 kg / m³. -2 h -1 At night, in the absence of light, with an applied voltage of 3V, the evaporation rate of pure water is 0.3 kg / m³. -2 h -1 The seawater evaporation rate is 0.2 kg / m³. -2 h -1 .

[0114] Compare with Example 4:

[0115] This comparative example is essentially the same as Example 4, except that a photoelectric composite functional layer is not constructed. The composite material consisting only of a hydrophilic absorbent core and a sleeve with vertical holes lacks light absorption and photothermal conversion capabilities, relying on natural evaporation of water. Furthermore, the absorbent core and the sleeve with vertical holes are non-conductive, preventing water evaporation through an applied voltage at night. The test results are as follows: 1000 W / m 2 Under simulated continuous sunlight exposure for 24 hours, the evaporation rate of pure water is 0.4 kg m³. -2 h -1 The seawater evaporation rate is 0.5 kg / m³. -2 h -1 .

[0116] In addition, the inventors of this case also conducted experiments with other raw materials and conditions listed in this specification, referring to Examples 1-4, and similarly obtained high-performance three-dimensional composite materials with low fluid resistance and vertical pore structure.

[0117] It should be understood that the above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformations or equivalent substitutions fall within the scope of protection of the present invention.

Claims

1. A method for preparing a low-fluid-resistance three-dimensional material with a vertical pore structure, characterized in that, include: (1) Mix agar, organic matter, water and additives evenly to form a micro-crosslinked polymer solution; The micro-crosslinked polymer solution is placed in a mold with a vertical pore structure and allowed to stand and dry to obtain a hydrophilic absorbent core. (2) Mix the polymer, polyacrylic acid, small molecule base and organic solvent uniformly to form a polymer solution, and then place the polymer solution in the mold containing the hydrophilic absorbent core obtained in step (1) and freeze it to form a low fluid resistance vertical hole polymer sleeve on the local surface of the hydrophilic absorbent core. (3) Apply a first mixed aqueous solution containing metal salt and organic acid to the low fluid resistance vertical hole polymer sleeve with hydrophilic liquid-absorbing core prepared in step (2) and carry out the first reaction. Then, immerse it in 2-methylpyrazole aqueous solution to carry out the second reaction, thereby growing a low crystal metal-organic framework transition layer in situ on the surface of the low fluid resistance vertical hole polymer sleeve. (4) Copper sulfide particles are grown in situ on the surface of the low-crystal metal-organic framework transition layer obtained in step (3) to form a photoelectric composite functional layer, thereby obtaining a three-dimensional material with low fluid resistance and vertical pore structure.

2. The preparation method according to claim 1, characterized in that, Step (1) includes: adding agar and organic matter to water and stirring to dissolve them, then adjusting the pH value to 1-5, and then adding additives to obtain the micro-crosslinked polymer solution; And / or, the organic matter includes any one or a combination of two or more of polyvinyl alcohol, sodium alginate, and chitosan; And / or, the additives include any one or a combination of two or more of glutaraldehyde, glycerol, and sorbitol; And / or, the agar content in the micro-crosslinked polymer solution is 0.5–8 wt%; And / or, the organic content in the micro-crosslinked polymer solution is 0.5–10 wt%; And / or, the content of the additive in the micro-crosslinked polymer solution is 0.1 to 5 wt%; And / or, the settling temperature is 10-60°C, and the settling time is 5 min-2 h.

3. The preparation method according to claim 2, characterized in that: In step (1), the temperature for stirring and dissolving is 10–100°C, and the stirring and dissolving time is 0.5–8 h; And / or, step (1) includes: adding hydrochloric acid to adjust the pH value to 1-5.

4. The preparation method according to claim 1, characterized in that, Step (2) includes: adding the polymer, polyacrylic acid and small molecule base to an organic solvent, stirring to dissolve, and obtaining a polymer solution; then placing the polymer solution in a mold containing a hydrophilic absorbent core obtained in step (1) and freezing it, then taking it out and immersing it in salt water to remove the mold; And / or, the polymer includes any one or a combination of two or more of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, and polysulfone; And / or, the small molecule base includes any one or a combination of two or more of ammonia, urea, and triethylamine; And / or, the organic solvent includes any one or a combination of two or more of dimethyl sulfone, dimethyl sulfoxide, and N-methylpyrrolidone; And / or, the polymer content in the polymer solution is 2-30 wt%; And / or, the content of polyacrylic acid in the polymer solution is 1 to 10 wt%; And / or, the content of small molecule base in the polymer solution is 0.1-5 wt%; And / or, the freezing temperature is -60 to 0°C, and the freezing time is 1 to 24 hours.

5. The preparation method according to claim 4, characterized in that: In step (2), the temperature for stirring and dissolving is 10–120°C, the stirring and dissolving time is 0.5–24 h; and / or, the concentration of the brine is 1–30 wt%.

6. The preparation method according to claim 1, characterized in that, Step (3) includes: pouring a first mixed aqueous solution containing metal salt and organic acid onto the low fluid resistance vertical hole polymer sleeve with hydrophilic liquid-absorbing core prepared in step (2), performing a first reaction at 10-100°C for 0.5-24 h, and then immersing it in a 2-methylpyrazole aqueous solution for a second reaction at 10-100°C for 10 s-24 h, thereby growing a low crystallinity metal-organic framework transition layer in situ on the surface of the low fluid resistance vertical hole polymer sleeve; And / or, the metal salt includes any one or a combination of two or more of ferric chloride, ferric nitrate, and ferric sulfate; And / or, the organic acid includes any one or a combination of two or more of fumaric acid, acetic acid, and 2-aminoterephthalic acid; And / or, the content of the metal salt in the first mixed aqueous solution is 0.5 to 5 wt%; And / or, the content of organic acid in the first mixed aqueous solution is 0.1 to 15 wt%; And / or, the concentration of the 2-methylpyrazole aqueous solution is 0.01–10 wt%; And / or, step (4) includes: immersing the composite material obtained in step (3) in a second mixed aqueous solution containing copper salt and conductive material, and maintaining it at 10-40°C for 5 min-24 h, and then immersing it in ammonium sulfide solution for 30 s-1 h, thereby growing copper sulfide particles in situ on the surface of the low-crystal metal-organic framework transition layer.

7. The preparation method according to claim 6, characterized in that: In step (4), the copper salt includes any one or a combination of two or more of copper nitrate, copper chloride, and copper sulfate; and / or, the conductive material includes any one or a combination of two or more of carbon nanotubes, polypyrrole particles, and Mxene nanosheets. And / or, the copper salt content in the second mixed aqueous solution is 2 to 20 wt%; And / or, the content of conductive material in the second mixed aqueous solution is 0.01-2 wt%; And / or, the concentration of the ammonium sulfide solution is 2 to 14 wt%.

8. A low-fluid-resistance three-dimensional material with a vertical pore structure prepared by the preparation method according to any one of claims 1-7, characterized in that, The low fluid resistance three-dimensional material comprises, from the inside out, a hydrophilic absorbent core, a low fluid resistance vertical hole polymer sleeve, and a photoelectric composite functional layer. The photoelectric composite functional layer includes a low-crystalline metal-organic framework transition layer and copper sulfide particles distributed on the surface of the low-crystalline metal-organic framework transition layer. The low fluid resistance vertical hole polymer sleeve is fitted onto a local surface of the hydrophilic absorbent core, and the photoelectric composite functional layer is coated on the surface of the low fluid resistance vertical hole polymer sleeve.

9. The low fluid resistance three-dimensional material with a vertical hole structure according to claim 8, characterized in that: The ratio of the diameter or side length of the hydrophilic liquid-absorbing core, the thickness of the low fluid resistance vertical hole polymer sleeve, and the thickness of the optoelectronic composite functional layer is 1-10:1-30:1-3. And / or, the shape of the hydrophilic absorbent core includes cylindrical or square; And / or, the thickness of the low-crystallinity metal-organic framework transition layer is 50 nm to 400 μm; And / or, the particle size of the copper sulfide particles is 10 nm to 500 μm; And / or, the low fluid resistance three-dimensional material is subjected to 1000 W / m 2 Under simulated continuous 24-hour sunlight exposure, the evaporation rate of pure water is 5.2 kg / m³. -2 h -1 The seawater evaporation rate is 4.9 kg / m³. -2 h -1 The above; at night without light, with an applied voltage of 3V, the evaporation rate of pure water is 4.5 kg / m³. -2 h -1 The seawater evaporation rate is 4.2 kg / m³. -2 h -1 above.

10. The application of the low fluid resistance three-dimensional material with vertical pore structure as described in claim 8 or 9 in the field of photothermal-electrothermal seawater desalination.

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