CN112747482A - Device with efficient photo-thermal conversion performance and application thereof - Google Patents

Abstract

Translated fromChinese

本发明属于能源环境应用领域，具体涉及一种具有高效光热转化性能的装置及其应用。装置为多个具有中空结构的多孔毛细管和至少一层的具有漂浮能力的支撑板组成；支撑板设有通孔，通孔中插有具有中空结构的多孔管。所述装置在海水蒸发淡化中的应用。本发明具有高效光热转化性能的光热毛细管竖直阵列结构，实现对照射角度光的高效吸收利用，保持蒸发效率温度。同时其毛细管结构促进水和离子的传输扩散，在保证蒸发水供给的同时，避免盐离子析出污染。The invention belongs to the field of energy and environmental applications, and in particular relates to a device with high-efficiency photothermal conversion performance and its application. The device is composed of a plurality of porous capillaries with hollow structures and at least one layer of support plates with floating ability; the support plates are provided with through holes, and the porous tubes with hollow structures are inserted into the through holes. Application of the device in seawater evaporation and desalination. The invention has a photothermal capillary vertical array structure with high photothermal conversion performance, realizes efficient absorption and utilization of irradiated angle light, and maintains the evaporation efficiency temperature. At the same time, its capillary structure promotes the transmission and diffusion of water and ions, which ensures the supply of evaporated water and avoids the precipitation of salt ions.

Description

Device with efficient photo-thermal conversion performance and application thereof

Technical Field

The invention belongs to the field of energy environment application, and particularly relates to a device with high-efficiency photo-thermal conversion performance and application thereof.

Background

The seawater evaporation process driven by sunlight can directly separate fresh water from the ocean, is an ideal seawater desalination mode, and has very high application prospect. In the law nature, mankind utilizes the natural evaporation and separation process of fresh water by means of a solar distiller. However, the natural evaporation process is slow, and the efficiency is low, so the application is greatly limited, and the daily water demand in coastal and island regions cannot be met.

The evaporation interface is heated intensively by utilizing the photo-thermal material which can efficiently capture solar energy and convert the solar energy into heat energy, so that high evaporation interface temperature can be obtained, and the water evaporation rate is accelerated. Researchers have successively developed and reported various photothermal materials to meet the requirements of water evaporation, especially seawater evaporation process (Peng Wang, Environmental Science: Nano 2018,5, 1078; Chengni steel, Liu Zi, Zhang Qi, Zhang Lisha, Chao Tianya, Zhubo, He Shuang, Baghuyi, a polyacrylonitrile/copper sulfide photothermal nanofiber cloth and its preparation and application, CN 106637921B). However, the two-dimensional planar photothermal film material has a large bottleneck in light absorption and energy utilization, and it is difficult to effectively reduce energy loss caused by thermal radiation and thermal convection. In addition, in actual lighting conditions, the sunlight angle changes with time, and the planar photothermal film cannot ensure efficient light absorption and utilization at variable angles, resulting in a severe decrease in the evaporation rate.

Compared with the prior art, the photo-thermal device with the three-dimensional macroscopic geometrical morphology can overcome the defects of a planar photo-thermal film in the aspect of energy utilization, and more efficient photo-thermal evaporation is realized. But simultaneously, due to the increase of the space geometric dimension, the transmission and diffusion of water and ions become important factors for restricting the photo-thermal evaporation rate, and the membrane is polluted by salt precipitation. Therefore, the selection of proper units to construct the three-dimensional macroscopic geometric morphology has important significance for realizing the stability of seawater evaporation efficiency and salt pollution resistance under the condition of multi-angle illumination.

Disclosure of Invention

The invention aims to provide a device with high-efficiency photothermal conversion performance and application thereof.

In order to achieve the purpose, the invention adopts the technical scheme that:

a device with high-efficiency photothermal conversion performance comprises a plurality of porous capillary tubes with hollow structures and at least one layer of supporting plate with floating capacity; the supporting plate is provided with a through hole, and a porous pipe with a hollow structure is inserted into the through hole.

The through hole of the support plate is inserted with a porous capillary tube with a hollow structure, the photo-thermal capillary tube on the support plate can be randomly adjusted in relative height, and the distance between the lower end of the porous capillary tube with the hollow structure and the lower surface of the support plate is 0-19cm, preferably 1.5-4.5 cm.

The through holes formed in the supporting plate are arranged in a geometric figure form.

The porous capillary tube with the hollow structure is equal in length; the distance between the upper end of the adjacent porous capillary tube with the hollow structure and the lower surface of the support plate has a height difference.

According to the pattern designed on the supporting plate, the porous capillary tube with a hollow structure is inserted into the supporting plate, and the relative height of each tube and the lower surface of the supporting plate is adjusted, so that the array structure is changed to form different geometric appearances.

A plurality of rows of through holes are formed in the supporting plate according to a geometric figure, the length of the porous capillary tube with the hollow structure in each row (horizontal row or vertical row) of through holes above the upper surface of the supporting plate is equal, and the length of the porous capillary tube with the hollow structure inserted into each row of holes above the upper surface of the supporting plate is increased or decreased from one side to the other side to form a vertical array structure;

or, the length of the porous capillary tube with the hollow structure in each row (horizontal row or vertical row) of through holes on the upper surface of the support plate is equal, and the height difference is formed between the top ends of the porous capillary tubes with the hollow structure, into which the holes in two adjacent rows are inserted, so as to form a vertical array structure;

or, the supporting plate is provided with a plurality of rows of through holes according to a geometric figure, wherein the geometric figure is an axisymmetric figure, the two sides of the symmetry axis are symmetrically arranged, and the height between the porous capillary tube with the hollow structure and inserted into the through hole and the upper surface of the supporting plate is gradually reduced from the edge row to the middle row or gradually reduced from the middle row to the edge row; the length of the porous capillary tubes with the hollow structure in each row of the insertion through holes on the upper surface of the support plate is equal.

The distance between any two adjacent porous capillaries with hollow structure is 1-20 mm, preferably 2-5 mm.

The geometric figure is a circle, a polygon or an irregular figure; wherein the polygon comprises a triangle, a quadrangle, a pentagon, a hexagon and an octagon.

The tube wall of the porous capillary tube with the hollow structure is of a porous structure, the aperture is 10-5000 nanometers, and pores with different apertures are preferably distributed on the tube wall, wherein the different apertures can be of a hierarchical pore structure with two pore sizes of one or more of the pores with the aperture sizes of 50-500 nanometers, the pore sizes of 1-10 micrometers and the pore sizes of 500-1000 nanometers;

the inner diameter of the capillary is 50-5000 microns, the wall thickness is 50-2000 microns, the length is 1-20 cm, the preferred inner diameter is 200-1000 microns, the wall thickness is 200-800 microns, and the length is 1-5 cm; the outer surface of the capillary is modified with a photo-thermal coating to form a hydrophilic tubular material.

The functional photo-thermal coating is polypyrrole, a carbon material or a cobalt-containing black pigment.

The surface modification method of the functional photothermal coating comprises the steps of chemical oxidative polymerization deposition, impregnation and physical deposition. Further, the following steps are carried out:

1) chemical oxidative polymerization deposition is carried out by immersing the capillary tube in an oxidizing agent one or more times and then naturally drying the capillary tube.

Placing the capillary tube and pyrrole obtained by the treatment in a closed container, and preserving heat for 5-300min at 4-150 ℃; wherein, the dosage of the pyrrole is 0.1-10 mu L per square centimeter of the surface area of the substrate material; the preferable temperature is 70-110 ℃, the reaction time is 60-120min, and the dosage of the functional photothermal polymer is 0.5-2 mu L per square centimeter of capillary surface area.

And taking out after reaction, washing with deionized water and ethanol in sequence until a washing solution is colorless, and naturally drying.

The oxidant is in the concentration range of 1.0mmol L^-1-2.0mol L^-1Preferably 0.2 to 1.0mol L of an aqueous or alcoholic solution of ferric trichloride or ammonium persulfate^-1Aqueous ferric chloride solution

2) The dipping is that the capillary tube is dipped into the water solution or organic solution prepared by the carbon material with the photo-thermal function and the black pigment containing cobalt, taken out and dried, and dipped for one time or a plurality of times.

The carbon material comprises carbon nano-tubes, graphene, carbon quantum dots, activated carbon and ink, and the cobalt-containing black pigment comprises spinel type oxide or a mixture of several oxides formed by cobalt and other metals.

The solvent of the aqueous solution is pure water or aqueous solution containing surfactant, and the content of the surfactant is 0.1-5 wt%. The organic solvent comprises ethanol, methanol, acetone, diethyl ether, toluene, N-methyl pyrrolidone, ethylene glycol, petroleum ether, and ethyl acetate.

The concentration of the photothermal material in the above solution is 0.2-2 wt%

3) The physical deposition is to prepare solution or suspension of photo-thermal material including polypyrrole, carbon material and cobalt-containing black pigment, deposit the solution or suspension on the surface of the capillary tube by spraying and vacuum filtration, and dry the solution or suspension to obtain the photo-thermal material.

The solvent is pure water or water solution containing surfactant, and the surfactant content is 0.1-5 wt%. The organic solvent comprises ethanol, methanol, acetone, diethyl ether, toluene, N-methyl pyrrolidone, ethylene glycol, petroleum ether, and ethyl acetate.

The concentration of the photo-thermal material in the solution is 0.05-0.5 wt%.

The support is a support plate with floating capacity, and the plate is made of polymer and wood and can float on the water surface; polystyrene foam or cork board is preferred.

The thickness of the support plate is 0.1-5 cm, preferably 0.3-1.0 cm.

The support plate may be a single layer or a plurality of layers, preferably a single layer or two layers.

The vertical array structure can directly or indirectly absorb one or more of ultraviolet light, visible light, infrared light and sunlight to form composite light; and the light with the irradiation angle of 0-180 degrees is efficiently captured and absorbed by the vertical array structure with different geometric appearances.

The application of the device with high-efficiency photothermal conversion performance, and the application of the photothermal capillary tube array structure forming device in seawater evaporation and separation of fresh water.

The photo-thermal capillary vertical array structure with high-efficiency photo-thermal conversion performance can be used for accelerating water evaporation by utilizing light energy.

The invention has the following advantages:

the photo-thermal capillary vertical array structure with the efficient photo-thermal conversion performance realizes efficient absorption and utilization of light at an irradiation angle, and maintains the evaporation efficiency and temperature. Meanwhile, the capillary structure promotes the transmission and diffusion of water and ions, and avoids salt ion precipitation pollution while ensuring the supply of evaporated water; further, the following steps are carried out:

(1) utilize the hydrophilicity light and heat capillary that has suitable internal diameter and length, can promote the sea water to the capillary top through capillary action, effectual water and the ion transmission who accelerates the evaporation process not only can provide sufficient water supply for the evaporation interface, simultaneously can effectually with the high concentration ion transmission diffusion to the water of evaporation interface department, avoid reaching the saturation to avoid salting out and pollute light and heat capillary

(2) The photo-thermal capillary vertical array obtained by the invention can adjust the height of any capillary according to the actual illumination condition, thereby obtaining different three-dimensional geometric shapes, realizing effective absorption and utilization of sunlight with variable irradiation angles and ensuring the stability of evaporation efficiency. The illumination angle is reduced from 90 degrees to 0 degree, the average temperature change of the surface of the photothermal capillary vertical array is not more than 2 degrees, and the evaporation rate is reduced by not more than 10 percent. The water evaporation rate is improved by more than 400 percent compared with the two-dimensional plane photo-thermal film made of the same material.

Drawings

FIG. 1 is a schematic diagram of a process for preparing a device with high efficiency photothermal conversion performance according to example 1 of the present invention;

FIG. 2 is a SEM cross-sectional view of a polypyrrole deposition surface modified photo-thermal capillary of example 1 of the present invention;

FIG. 3 is an SEM cross-sectional enlarged picture of a polypyrrole deposition surface modified photo-thermal capillary of example 1 of the present invention;

FIG. 4 is an SEM surface picture of the polypyrrole deposition surface modified photo-thermal capillary mesoporous framework of example 1 of the present invention;

FIG. 5A is a schematic view of a vertical array of photothermal capillary tubes with different geometries according to example 1 of the present invention;

FIG. 5B is a schematic structural view of a supporting plate having an irregular pattern according to embodiment 1 of the present invention;

FIG. 5C is a schematic diagram of a vertical array of photothermal capillary tubes with different geometries according to example 1 of the present invention;

FIG. 5D is a schematic diagram of a vertical array of photothermal capillary tubes with different geometries according to example 1 of the present invention;

FIG. 6 is a photograph showing a test of water contact angle of the surface of the photothermal capillary of example 1 of the present invention;

FIG. 7 is a graph showing light absorption data of a cross-section of a photothermal capillary of example 1 of the present invention measured by UV-vis-IR, in a wavelength range of 250nm to 2500 nm;

FIG. 8 shows the average surface temperature at 1kW m intensity of the vertical photo-thermal capillary array structure with different geometries according to example 1 of the present invention under different illumination angles^-2Testing under simulated sunlight;

FIG. 9 shows a vertical array of photothermal capillary structures at an intensity of 1kWm according to example 1 of the present invention^-2Simulating the evaporation rate test of seawater under sunlight and the salt precipitation test in the evaporation process;

FIG. 10 shows a vertical array of photothermal capillary structures at an intensity of 1kWm according to example 1 of the present invention^-2Simulating the evaporation rate test of water under the sun illumination at different angles;

fig. 11 is a photo-thermal capillary diagram obtained by deposition modification of a composite surface of a carbon nanotube and graphene in a physical deposition reduced pressure filtration manner according to example 3 of the present invention;

FIG. 12 is an SEM cross-sectional picture of a photothermal capillary having a non-porous diameter and a thick wall of example 4 of the present invention;

FIG. 13 is a photograph showing examples of photothermal capillaries having different lengths according to example 4 of the present invention;

FIG. 14 is a graph of the comparison of the efficiency of diffuse reflection and light absorption of a vertical array of photothermal capillary structures and planar films of the same materials, in the wavelength range of 250nm to 2500 nm;

FIG. 15 shows a photo-thermal capillary vertical array structure with different morphologies under different light conditions according to an embodiment of the present inventionThe surface average temperature under the illumination angle and the simulated sunlight intensity are 1kWm^-2；

Fig. 16 is a schematic view of a photothermal evaporation test system according to an embodiment of the present invention.

Detailed Description

The invention is further illustrated, but not limited, by the following examples in connection with the accompanying drawings.

The material of the invention takes an alumina capillary as a substrate, ferric trichloride or ammonium persulfate as an oxidant to initiate functional polypyrrole in-situ polymerization deposition, and the photo-thermal functionalized capillary is inserted into a polystyrene foam board to form an adjustable photo-thermal capillary vertical array structure. The preparation method of the photo-thermal capillary vertical array structure comprises the following steps: impregnation loading of an oxidant, chemical oxidation polymerization surface modification and geometric shape modulation. The photo-thermal capillary vertical array structure greatly promotes the evaporation efficiency of water.

Example 1

The preparation method of the device with high-efficiency photothermal conversion performance is shown in figure 1:

1) the preparation method of each photo-thermal capillary tube with high-efficiency photo-thermal conversion performance comprises the following steps:

(1) each alumina capillary having an inner diameter of 1.0mm, a wall thickness of 0.65mm and a length of 25mm was immersed in a solution of 0.5mol L^-1And (4) standing the mixture for 30min at room temperature in an ammonium persulfate aqueous solution, taking out the mixture, and drying the mixture at room temperature.

(2) And (2) putting 6 mu L of pyrrole into a container, and sealing a plurality of alumina capillaries loaded with ammonium persulfate oxidant and obtained by the method prepared in the step (1) into the container together. The temperature was maintained at 50 ℃ for 2 hours. The amount of pyrrole used corresponds to 0.55 μ L per square centimeter of surface area of the hollow fiber base material.

(3) And (3) washing the surface-modified alumina capillary tube obtained in the step (2) with deionized water, and drying to obtain the capillary tube with the outer surface modified and the hollow structure (see figures 2, 3 and 4).

As can be seen from figures 2, 3 and 4, the pore structure of the capillary wall still exists after the polypyrrole is deposited, the polypyrrole is coated on the surface of the alumina framework, and the deposition thickness is about 100 nm.

2) The device with high-efficiency photothermal conversion performance is obtained:

(4) a polystyrene foam plate with the thickness of 3mm is used as a supporting plate, 37 holes are formed in the supporting plate through a drill with the diameter of 2.3mm, and the distance between the circle center of each hole and the circle center of the adjacent hole is 4.3 mm. 37 holes are formed in an equal hexagonal arrangement, and the number of the holes in each row is 4, 5, 6, 7, 6, 5 and 4 in sequence from one side to the other side.

And (4) sequentially and vertically inserting the photothermal capillary tubes obtained in the step (3) into the open-cell polystyrene foam support plates. When all capillaries are inserted into the support plate, the top ends of the capillaries are flush with the upper surface of the support plate, and a high-temperature capillary array with the height h equal to 0mm is formed (the left picture of fig. 5A). When all capillaries were inserted into the support plate, the capillary tips exceeded the upper surface of the support plate by 15mm, forming a vertical array of equal height photothermal capillaries with a height h of 15mm (fig. 5A). When the insertion heights of 7 rows of capillaries sequentially increase from one side h being 0mm to 3mm, 6mm, 9mm, 12mm, 15mm and 18mm, a step-shaped photothermal capillary vertical array is formed (the right picture of fig. 5A). According to the illumination angle, the overall height of the equal-height array or the level height of the step-shaped array can be adjusted by adjusting the height of the capillary inserted into the supporting plate. (see FIG. 5A).

A plurality of rows of through holes are formed in the supporting plate, each row is provided with a plurality of through holes, and the formed through holes form geometric figures such as circles, polygons or irregular images (see fig. 5B); the patterns formed on the supporting plate are pentagonal, the length of the porous capillary tubes with the hollow structures in the through holes of each row (horizontal row or vertical row) on the upper surface of the supporting plate is equal, and the height difference is formed between the top ends of the porous capillary tubes with the hollow structures inserted into the holes of two adjacent rows, so that a vertical array structure is formed (see fig. 5C);

the geometric figure on the supporting plate is an axisymmetric figure (such as a hexagon), the two sides of the symmetric axis are symmetrically arranged, and the height between the porous capillary tube with the hollow structure inserted into the through hole and the upper surface of the supporting plate is gradually reduced from the edge row to the middle row, or gradually reduced from the middle row to the edge row; the length of the porous capillary tubes with the hollow structure in each row of the insertion through holes on the upper surface of the support plate is equal. (see FIG. 5D).

The vertical array of capillaries formed as seen in fig. 5 can form a height-adjustable array by adjusting the height of a single capillary, including an array structure in which all capillaries have the same height, and a stepped array structure facing the light source. Aiming at different light irradiation angles, the height difference of the stepped array structure can be adjusted, a light receiving surface vertical to the light irradiation angles is formed, and efficient capturing and absorption of light are achieved. The stepped array of tubes inserted at the same time may be sequentially raised in any horizontal direction, e.g., from left to right or from front to back, depending on the angle of illumination.

The performance of the photothermal capillary vertical array structure of the above example was determined:

1) the photothermal capillary tube having high efficiency photothermal conversion performance obtained in the above example was fixed on a flat surface, and a 4 μ L drop of pure water was used as a probe, and a water contact angle test of the surface of the photothermal capillary tube was performed by recording and data processing with a static contact angle measuring instrument (see fig. 6),

as can be seen in fig. 6, the photothermal capillary surface is hydrophilic. The hydrophilic surface helps to transport water from the capillary base to the entire capillary surface. Meanwhile, according to a capillary rising formula, inside the capillary, the hydrophilic surface lowers the water contact angle, so that the height of water in the photothermal capillary is increased, and sufficient water transfer is promoted.

2) The light absorption test was performed by UV-vis-IR on the cross section thereof (see FIG. 7). In the test, in order to ensure that the section of the capillary can cover the whole detection light spot of the UV-vis-IR instrument, 30 photo-thermal capillaries are fixed into a bundle for testing. And directly testing the light transmittance of the photo-thermal capillary tube bundle, testing the diffuse reflectance of the photo-thermal capillary tube bundle by using an integrating sphere, and calculating the absorbance.

As can be seen from FIG. 7, the total absorption efficiency of the photothermal capillary to light in the range of 250-2500nm is 96.4%, and the average absorbance under the soaking condition can reach 97.8%.

The absorption capacity of the capillary cross section for light in the wavelength range of solar light is known from this measurement. The integral absorption efficiency of the photothermal capillary tube reaches a higher level under a dry condition, which shows that the photothermal capillary tube has high light capture absorption capacity. The wetted photo-thermal capillary tube is under the simulated evaporation condition, the average absorbance of the capillary tube is further improved, and the capillary tube array can absorb more light energy in the evaporation process.

3) The devices prepared in the above examples, which were stepped toward the light source (fig. 5, left) and had capillary tips 15mm above the upper surface of the support plate, were tested for surface average temperature at different illumination angles (0-90 °) for devices that formed a vertical array of highly photothermal capillaries (fig. 5A) having a height h of 15mm (see fig. 8).

In fig. 8, a step-like array facing the light source (fig. 5, left side) is seen, that is, the height of the photothermal capillary tube at a position closer to the light source is lower, and the height of the photothermal capillary tube at a position farther from the light source is sequentially higher. The surface average temperature was measured by direct observation with a thermal infrared imager.

A vertical array of equal height photothermal capillaries (fig. 5A) with a height h of 15mm is formed, i.e., the tips of all the capillaries inserted into the support plate exceed the upper surface of the support plate by 15 mm.

And by adjusting the geometric morphology of the vertical array of the photothermal capillary, when the illumination angle is reduced from 90 degrees to 0 degrees, the average temperature of the upper surface of the vertical array is reduced by no more than 2 ℃.

4) The photo-thermal capillary array devices prepared in the above examples and having equal height were tested for comparison of water evaporation rates at different illumination angles (see fig. 9). The testing apparatus is shown in fig. 16, the illumination angle is realized by modulating the position of the light source, and the distance between the light source and the array apparatus is kept constant. The test aims at verifying whether the photothermal capillary array macro-morphology modulation can realize effective photothermal conversion under different illumination angles to promote water evaporation.

The height of the array device with uniform height is h 15mm (fig. 5A) and h 0mm (fig. 5A, left), and a sheet-like planar photothermal film (planar) of the same material is used for comparison.

As can be seen from fig. 9, the evaporation rate can be reduced by no more than 10% since the actual illuminated area can be increased by increasing the area of the tube wall exposed and illuminated. Compared with a planar photothermal film, the photothermal capillary array capable of modulating the macroscopic morphology can effectively utilize light energy at different angles and promote efficient and stable water evaporation.

It can be seen that the light intensity was controlled at 1kW m at the test position^-2Compared with a planar photo-thermal material made of the same material, the photo-thermal capillary vertical array structure can achieve a faster photo-thermal water evaporation rate.

5) The photothermal capillary array device prepared in the above example was tested for evaporation of actual seawater (see fig. 10). The test apparatus is shown in fig. 16, with actual seawater in the cup. The test aims at verifying the photothermal evaporation performance of the photothermal capillary array device on actual seawater, resisting salt precipitation and avoiding the salt pollution capacity.

The test specifically comprises the following steps: photothermal capillaries having total lengths of heights of 40mm and 25mm, respectively, were inserted into the polystyrene foam boards to expose heights of 37mm and 22mm, respectively. The test water sample is real seawater, the simulated solar light source provides illumination, and the light intensity of the test position is kept to be 1kW m^-2The test was carried out at ambient temperature 25. + -. 0.5 ℃ and humidity 50. + -. 5%.

As can be seen from fig. 10, when the photothermal capillary exceeds a certain length, the top water and ion transport diffusion rate cannot satisfy the water evaporation rate, the salt ions gradually reach saturation, and the salt precipitates the contaminated photothermal capillary.

Meanwhile, the evaporation rate of the photo-thermal capillary vertical array to seawater can reach 4kg m^-2h^-1And no salt is separated out in long-time evaporation test.

In addition, the vertical array structure constructed by the 25mm photothermal capillary tube can stably operate for 20 hours for the photothermal evaporation of the seawater, and the stable evaporation efficiency is kept.

Example 2

The difference from the embodiment 1 is that:

and (2) respectively replacing the alumina capillary in the step (1) with silica, porous ceramic or diatomite, or hydrophilic cellulose acetate, polycarbonate, polyamide, mixed cellulose ester, polyacrylonitrile or polyethylene film.

Example 3

The difference from the embodiment 1 is that:

and (2) respectively replacing the photo-thermal material in the step (1) with one or a mixture of carbon materials of carbon nano tubes, graphene, carbon quantum dots, activated carbon and ink, or black dye of spinel type oxide or a mixture of a plurality of oxides formed by cobalt and other metals.

The modification method is physical deposition. Specifically, the method comprises the following steps: preparing N-methyl pyrrolidone solution containing carbon materials or water solution/suspension of cobalt-containing black dye, wherein the concentration is 0.1 wt%, blocking one end of the capillary tube, depositing the photo-thermal material on the surface of the capillary tube in a reduced pressure suction filtration mode, and drying, as can be seen in figure 11.

Fig. 11 shows that the photothermal capillary tube with the photothermal layer being the carbon nanotube can be prepared by a reduced pressure suction filtration method, and pure water is dropped on the surface of the photothermal capillary tube, so that the water contact angle of the surface is small, which indicates that the capillary tube surface with the photothermal layer being the carbon nanotube is hydrophilic.

Example 4

The difference from the embodiment 1 is that:

setting the sizes of the alumina capillary in the step (1) to be 0.8mm and 1.2mm respectively; the wall thickness is 0.5mm, 0.7mm and 0.8 mm; length 40mm as can be seen in fig. 12 and 13.

As can be seen from the scanning electron micrograph of fig. 12, alumina capillaries with different inner diameters/wall thicknesses were successfully prepared.

As can be seen from FIG. 13, an alumina capillary tube having a length of 40mm can be fabricated and modified to provide a photothermal capillary tube.

Example 5

The difference from the embodiment 1 is that:

the concentrations of the oxidizing agents impregnated in the step (2) were set to 0.01mol L, respectively^-1、0.1mol L^-1、0.2mol L^-1、0.5mol L^-1、1mol L^-1The oxidant is ferric trichloride water solution or ferric trichloride water and ethanol solution, and the volume ratio of the water to the ethanol is 1: 4.

Example 6

The difference from the embodiment 1 is that:

and (3) using the pyrrole in the step (2). The amounts of the above-mentioned components were set to 2. mu.L and 10. mu.L, respectively.

Example 7

The difference from the embodiment 1 is that:

setting the reaction temperature in the step (2) to be 30 ℃, 80 ℃ and 100 ℃, and setting the reaction time at each temperature to be 10min, 60min and 300 min.

The performance of the photothermal capillary vertical array structure of the above example was determined:

1) determination of light absorption:

photo-thermal functional coating as in example 5 above (0.5mol L)^-1Ferric trichloride in water and ethanol solution), and the photothermal capillaries are tied into bundles to measure the light absorption rate of the top surface of the photothermal capillaries according to the light absorption test scheme set forth in the performance test 2) of example 1, and meanwhile, a planar photothermal material of the photothermal functional coating is used as a reference, specifically, an ultraviolet-visible-near infrared spectrometer (UV-vis-NIR) is used for testing the light absorption rate of a sample in the sunlight wavelength range (250nm-2500nm) (see fig. 14).

Data from the uv-vis-nir spectrum show (see fig. 14) that the photothermal capillary has lower diffuse reflection efficiency and higher absorbance than the planar photothermal material.

2) The photothermal functional coating (0.5mol L) of the above example 5^-1Water and ethanol solution of ferric chloride) the resulting photothermal capillaries formed an array structure according tostep 2 of example 1 comparison of surface temperatures in air at different illumination angles (0-90 degrees):

the array structure is formed by forming a geometric figure (i.e., a hexagon) on the support plate described in step (4) of example 1, and when all the capillaries are inserted into the support plate, the capillary tips of the capillaries form a vertical array of high-temperature capillaries having different heights (h) beyond the upper surface of the support plate, and the height h is 0, 5,10, or 15 mm.

The photo-thermal capillary vertical array structure with different relative heights formed by the method has the strength of 1kW m^-2Analog TaiwanThe surface temperature of the array in air at different light and heat capillary heights and different light angles (0-90 degrees) is measured under sunlight for half an hour (see FIG. 15)

In the 15 visible light heat capillary vertical array structure, the higher the integral height of the capillary, the smaller the surface temperature change at a low illumination angle, and the higher the surface temperature. The formed stepped shape of the surface phase illumination direction can realize more uniform and higher surface temperature. At a strength of 1kW m^-2Simulating sunlight to vertically irradiate for half an hour, wherein the average temperature of the surface of the stepped morphology exceeds 41 ℃, and when the illumination angle is 0 ℃, the surface temperature is still close to 40 ℃.

3) Testing the water evaporation efficiency under different illumination conditions:

the photothermal capillary vertical arrays in all of the above examples were tested by the apparatus shown in fig. 16. For example, the photo-thermal capillary vertical array structure obtained in step 2) of example 1 (fig. 5A, right drawing) is subjected to a water evaporation efficiency test experiment under an illumination condition. The experiment is implemented by using a cylindrical transparent glass container to contain a test water sample, placing the container under a simulated solar light source, and keeping the light intensity of a test position at 1kW m^-2And the rate of water evaporation in dark conditions; and recording the mass change of the water in the container in real time by using an analytical balance connected to a computer end, thereby calculating the evaporation efficiency of the water under the illumination condition. The photo-thermal material is tested by placing the material on the surface of a test water sample to float naturally. The test was performed at ambient temperature 25. + -. 0.5 ℃ and humidity 50. + -. 5% with a data collection interval of 2 minutes (see FIG. 16).

The above-described embodiments are merely illustrative of preferred embodiments of the invention and are not to be construed as limiting the invention. Those skilled in the art may make modifications or alterations to the above-described embodiments without departing from the spirit and scope of the present principles. Therefore, it is intended that all modifications and variations which may occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the appended claims be interpreted as broadly as the following claims.

Claims (10)

Translated fromChinese

1.一种具有高效光热转化性能的装置,其特征在于：装置为多个具有中空结构的多孔毛细管和至少一层的具有漂浮能力的支撑板组成；支撑板设有通孔，通孔中插有具有中空结构的多孔管。1. a device with high-efficiency photothermal conversion performance is characterized in that: the device is composed of a plurality of porous capillaries with a hollow structure and at least one layer of support plates with floating ability; the support plates are provided with through holes, and the through holes A porous tube with a hollow structure is inserted.2.按权利要求1所述的具有高效光热转化性能的装置,其特征在于：所述支撑板的通孔中插有具有中空结构的多孔毛细管，具有中空结构的多孔毛细管下端与支撑板下表面的间距为0-19cm。2. The device with high-efficiency photothermal conversion performance according to claim 1, wherein a porous capillary with a hollow structure is inserted into the through hole of the support plate, and the lower end of the porous capillary with a hollow structure is connected to the bottom of the support plate. The spacing of the surfaces is 0-19cm.3.按权利要求1或2所述的具有高效光热转化性能的装置,其特征在于：所述支撑板上开设的通孔按照几何图形的形式设列。3. The device with high-efficiency light-to-heat conversion performance according to claim 1 or 2, characterized in that: the through holes opened on the support plate are arranged in the form of geometric figures.4.按权利要求3所述的具有高效光热转化性能的装置,其特征在于：所述具有中空结构的多孔毛细管等长；相邻的具有中空结构的多孔毛细管上端与支撑板下表面的间距具有高度差。4. The device with high-efficiency photothermal conversion performance according to claim 3, characterized in that: the porous capillaries with a hollow structure are of equal length; the distance between the upper end of the adjacent porous capillaries with a hollow structure and the lower surface of the support plate has a height difference.5.按权利要求4所述的具有高效光热转化性能的装置,其特征在于：所述支撑板上按几何图形开设多列通孔，每一列(横列或纵列)通孔中具有中空结构的多孔毛细管位于支撑板上表面上方的长度相等，各列的孔所插入的具有中空结构的多孔毛细管位于支撑板上表面上方的长度由一侧向另一侧递增或递减，形成竖直阵列结构；5. The device with high-efficiency light-to-heat conversion performance according to claim 4, characterized in that: the support plate is provided with a plurality of rows of through holes according to geometric figures, and each row (horizontal row or vertical row) of through holes has a hollow structure The lengths of the porous capillaries above the upper surface of the support plate are equal, and the lengths of the porous capillaries with hollow structures inserted into the holes of each row above the upper surface of the support plate increase or decrease from one side to the other, forming a vertical array structure. ;或，每一列(横列或纵列)通孔中具有中空结构的多孔毛细管位于支撑板上表面的长度相等，相邻两列的孔所插入的具有中空结构的多孔毛细管的顶端之间具有高度差，形成竖直阵列结构。Or, the lengths of the porous capillaries with a hollow structure in each row (course or column) of through holes located on the upper surface of the support plate are equal, and there is a height difference between the tops of the porous capillaries with a hollow structure inserted into the holes of two adjacent rows , forming a vertical array structure.6.按权利要求3所述的具有高效光热转化性能的装置,其特征在于：所述任意两个相邻的具有中空结构的多孔毛细管的间距为1-20毫米。6 . The device with efficient photothermal conversion performance according to claim 3 , wherein the distance between any two adjacent porous capillaries with a hollow structure is 1-20 mm. 7 .7.按权利要求1所述的具有高效光热转化性能的装置,其特征在于：所述具有中空结构的多孔毛细管的管壁为多孔结构，孔径为10-5000纳米，毛细管内径为50-5000微米，壁厚为50-2000微米，长度为1-20厘米；毛细管外表面修饰光热涂层形成亲水性管状材料。7. The device with high-efficiency photothermal conversion performance according to claim 1, wherein the wall of the porous capillary with a hollow structure is a porous structure, the pore diameter is 10-5000 nanometers, and the inner diameter of the capillary is 50-5000 nm Micron, the wall thickness is 50-2000 microns, and the length is 1-20 cm; the outer surface of the capillary is modified with a photothermal coating to form a hydrophilic tubular material.8.按权利要求7所述的具有高效光热转化性能的装置,其特征在于：所述功能光热涂层为聚吡咯、碳材料或含钴黑色颜料。8. The device with efficient photothermal conversion performance according to claim 7, wherein the functional photothermal coating is polypyrrole, carbon material or cobalt-containing black pigment.9.按权利要求4或7所述的具有高效光热转化性能的装置,其特征在于：所述形成竖直阵列结构可直接或间接的吸收紫外光、可见光、红外光、太阳光中的一种或几种形成的复合光；并通过形成的不同几何形貌的竖直阵列结构，实现对0-180°照射角度光高效捕获吸收。9. The device with high-efficiency photothermal conversion performance according to claim 4 or 7, wherein the vertical array structure is formed to directly or indirectly absorb one of ultraviolet light, visible light, infrared light, and sunlight. One or several kinds of composite light are formed; and through the formed vertical array structures with different geometric shapes, efficient capture and absorption of light with an irradiation angle of 0-180° can be achieved.10.一种权利要求1所述的具有高效光热转化性能的装置的应用,其特征在于：所述光热毛细管形成阵列结构装置在海水蒸发分离淡水中的应用。10 . An application of the device with efficient photothermal conversion performance according to claim 1 , wherein the photothermal capillary forming an array structure device is used in seawater evaporation and separation of freshwater. 11 .

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