Preparation method and system of water evaporation structure based on photon bandgap effect

Abstract

The application relates to the technical field of functional material preparation, in particular to a preparation method and system of a water evaporation structure based on a photonic band gap effect, which comprises the following steps: preparing a microsphere dispersion liquid, preparing a three-dimensional photonic crystal film through the microsphere dispersion liquid, preparing a photothermal material dispersion liquid, and dropping the photothermal material dispersion liquid on the three-dimensional photonic crystal film to obtain a water evaporation functional layer; and inserting the edge of the water evaporation functional layer into thermal insulation foam, and floating on the water surface to absorb sunlight to realize water evaporation. Through the application, a water evaporation method for realizing seawater desalination under sunlight by only using renewable energy is provided, which is favorable for realizing higher water evaporation efficiency, the evaporation process is stable and sustainable, meets the green environmental protection target, and the demand for instruments and materials is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional material preparation, and in particular to a preparation method and system of a water evaporation structure based on a photonic band gap effect. BACKGROUND

[0002] Fresh water on earth mainly comes from natural changes such as snow melting and rainfall, but with the continuous advancement of industrialization, the speed of fresh water regeneration is far behind the consumption speed of society, which has caused great challenges to human production and life. The vast oceans on earth account for 97.5% of the total amount of water resources, so that seawater desalination has become one of the key ways to solve the problem, and the strategy of using solar energy to evaporate seawater and then collecting fresh water has become a key research technology because of the advantages of abundant, stable and renewable energy sources.

[0003] Traditional solar seawater desalination devices often heat a large amount of water, so that precious energy is dissipated in the form of waste heat, and the complexity of large-scale seawater desalination devices also limits the application of the technology. In order to avoid heat propagation to the water body, interfacial heating on the water surface is an effective method, which transmits water molecules to the surface of the film through the capillary action of the porous material, evaporates on the gas-liquid interface, and then greatly reduces the heat loss and improves the energy utilization rate. Since water evaporation requires certain pores, the photothermal material layer should not be too thick, so the existing technology still has the problem that the photothermal material layer has low photon absorption rate. Based on the above problems, the present application provides a water evaporation film with high photon utilization rate. SUMMARY

[0004] The present application provides a preparation method and system of a water evaporation structure based on a photonic band gap effect, which can effectively solve the problems in the background art.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0006] The preparation method of the water evaporation structure based on the photonic band gap effect comprises:

[0007] Preparation of a microsphere dispersion liquid, and preparation of a three-dimensional photonic crystal film through the microsphere dispersion liquid;

[0008] Preparation of a photothermal material dispersion liquid, and dropping of the photothermal material dispersion liquid on the three-dimensional photonic crystal film to obtain a water evaporation functional layer;

[0009] Insertion of the edge of the water evaporation functional layer into a heat insulation foam, floating on the water surface to absorb sunlight to realize water evaporation.

[0010] Further, the preparation of the microsphere dispersion liquid and the preparation of the three-dimensional photonic crystal film through the microsphere dispersion liquid comprise:

[0011] Monodisperse microspheres were dispersed in ethanol and sonicated until uniformly dispersed to obtain a microsphere dispersion.

[0012] Take a hydrophilic filter membrane and place it horizontally on the table;

[0013] The microsphere dispersion was dropped onto the surface of a hydrophilic filter membrane, and the ethanol was evaporated at room temperature until completely dry to obtain a three-dimensional photonic crystal membrane.

[0014] Furthermore, the hydrophilic filter membrane is any one of PTFE, PVDF, or cellulose filter membrane.

[0015] Furthermore, the monodisperse microspheres are either silica or PMMA.

[0016] Furthermore, the concentration of the monodisperse microspheres is 15-30%, and the dropping volume is 4-7 μL per square centimeter.

[0017] Further, the step of preparing a photothermal material dispersion and dropping the photothermal material dispersion onto the three-dimensional photonic crystal film to obtain a water evaporation functional layer includes:

[0018] The photothermal material is dispersed in ethanol and sonicated until it is uniformly dispersed to obtain a photothermal material dispersion.

[0019] The photothermal material dispersion was dropped onto the surface of a three-dimensional photonic crystal film, and the ethanol was heated to evaporate until completely dry, thus obtaining a water evaporation functional layer.

[0020] Furthermore, the concentration of the photothermal material is 0.1-1%, the amount added is 1-5 μL per square centimeter, and the heating temperature is 50-70°C.

[0021] Furthermore, the insulating foam is either EPE or PS foam.

[0022] A system for fabricating water evaporation structures based on the photonic bandgap effect, the system comprising:

[0023] Three-dimensional photonic crystal film fabrication module: Prepares a microsphere dispersion, and fabricates a three-dimensional photonic crystal film using the microsphere dispersion;

[0024] Water evaporation functional layer preparation module: Prepare a photothermal material dispersion and drop the photothermal material dispersion onto the three-dimensional photonic crystal film to obtain a water evaporation functional layer;

[0025] Water evaporation module: The edge of the water evaporation functional layer is inserted into the heat insulation foam, and floats on the water surface to absorb sunlight to achieve water evaporation.

[0026] Furthermore, the three-dimensional photonic crystal film fabrication module includes:

[0027] Microsphere dispersion liquid obtaining unit: disperse monodisperse microspheres in ethanol, and ultrasonic until uniformly dispersed to obtain a microsphere dispersion liquid;

[0028] Hydrophilic filter membrane placing unit: take a hydrophilic filter membrane and horizontally place it on a table top;

[0029] Three-dimensional photonic crystal film obtaining unit: drop the microsphere dispersion liquid on the surface of the hydrophilic filter membrane, and evaporate the ethanol at room temperature until completely dry to obtain a three-dimensional photonic crystal film.

[0030] The technical scheme provided by the application can achieve the following technical effects:

[0031] The application provides a water evaporation method for seawater desalination under sunlight only by using renewable energy, which is beneficial to realize higher water evaporation efficiency, stable and sustainable evaporation process, meets the green and environmental protection goal, and has lower requirements for instruments and materials.

[0032] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, and can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specific embodiments of the application are described. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments described in the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0034] Figure 1 Flowchart of the preparation method of the water evaporation structure based on photonic bandgap effect;

[0035] Figure 2 Electron microscope diagram of the three-dimensional photonic crystal layer;

[0036] Figure 3 Structure diagram of the preparation system of the water evaporation structure based on photonic bandgap effect;

[0037] Figure 4 Diagram of the water evaporation structure;

[0038] Reference signs: 1, photo-thermal material layer; 2, three-dimensional photonic crystal layer; 3, hydrophilic filter membrane; 4, pore structure; 5, heat insulation foam. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0041] Embodiment one

[0042] As shown in the preparation method of the water evaporation structure based on the photonic band gap effect, the method comprises: Figure 1

[0043] S100: preparing a microsphere dispersion liquid, and preparing a three-dimensional photonic crystal film through the microsphere dispersion liquid;

[0044] Specifically, this step utilizes the ordered arrangement of microspheres to form a photonic crystal film to achieve specific optical properties, a photonic band gap effect, and by controlling the size, shape and dispersibility of the microspheres, the pore structure and optical properties of the photonic crystal film can be regulated. It should be noted that when preparing the microsphere dispersion liquid, the uniformity and dispersibility of the microsphere size need to be ensured to ensure the quality of the final film.

[0045] S200: preparing a photothermal material dispersion liquid, and dropping the photothermal material dispersion liquid on the three-dimensional photonic crystal film to obtain a water evaporation functional layer;

[0046] In this step, the photothermal material is introduced into the photonic crystal film to make it have a photothermal conversion function, form a water evaporation functional layer, and be able to absorb sunlight and convert it into heat energy. The photonic band gap effect of the three-dimensional photonic crystal layer provides higher photonic utilization rate for the photothermal layer, enhances the overall photothermal conversion efficiency, and accelerates the water evaporation process through the photothermal effect, thereby improving the water evaporation rate. By dropping the photothermal material dispersion liquid, the photothermal material is uniformly distributed on the surface of the photonic crystal film, ensuring the uniformity and stability of the functional layer. When uniformly dispersing the dispersion liquid, methods such as ultrasonic, magnetic stirring, high-pressure homogenization, etc. can be used. It should be noted that when the photothermal material dispersion liquid is dropped onto the photonic crystal film, the dropping speed and coating uniformity need to be controlled to ensure the uniformity and stability of the functional layer.

[0047] S300: inserting the edge of the water evaporation functional layer into the thermal insulation foam, floating on the water surface to absorb sunlight to realize water evaporation.

[0048] ​In the embodiment, the water evaporation functional layer edge is inserted into the heat insulation foam to form an integral whole, the water evaporation functional layer can float on the water surface by the buoyancy provided by the heat insulation foam, and the water evaporation functional layer is in full contact with the water surface, so that the evaporation of water is effectively promoted. The effective contact of the water evaporation functional layer with the water surface enables the water evaporation functional layer to fully utilize solar energy to accelerate the evaporation of water, thereby improving the water evaporation rate, and the stable position of the water evaporation functional layer and the water surface is maintained by the buoyancy support of the heat insulation foam, ensuring the effective work of the functional layer. In addition, the heat insulation foam can also reduce the heat conduction of water and the influence of the external environment on water, and improve the water evaporation efficiency.

[0049] The present application introduces a three-dimensional photonic crystal structure, on the one hand, a large number of pores in the structure can provide a channel for water migration, on the other hand, the photonic band gap effect can enhance the absorption of light by the photothermal material, and realize higher water evaporation efficiency. The pores of the three-dimensional photonic crystal generate capillary force to absorb water to the photothermal material layer, and the photothermal material absorbs near-infrared light to provide heat, and the photonic band gap effect of the photonic crystal further enhances the utilization rate of the photothermal material to the photons, and realizes efficient water evaporation on the gas-liquid interface.

[0050] Through the technical scheme of the present application, a water evaporation method is provided, which only uses renewable energy to realize seawater desalination under sunlight, which is conducive to realizing higher water evaporation efficiency, stable and sustainable evaporation process, meeting the green and environmental protection goal, and having lower demand for instruments and materials, and only using conventional and inexpensive materials to achieve the effect, which is suitable for large-scale industrial application.

[0051] Further, a microsphere dispersion liquid is prepared, and a three-dimensional photonic crystal film is made by using the microsphere dispersion liquid, including:

[0052] S110: dispersing monodisperse microspheres in ethanol, and ultrasonicating until uniformly dispersed to obtain a microsphere dispersion liquid;

[0053] S120: taking a hydrophilic filter membrane and placing it horizontally on a table top;

[0054] S130: taking the microsphere dispersion liquid and dropping it on the surface of the hydrophilic filter membrane, and evaporating ethanol at room temperature until completely dry to obtain a three-dimensional photonic crystal film.

[0055] As a preferred embodiment of the above embodiment, as Figure 2As shown, the three-dimensional photonic crystal film is composed of microspheres or pores with periodic structure, which can transport water, so a hydrophilic filter membrane is used as the base, and a three-dimensional photonic crystal structure is self-assembled on it with monodisperse microspheres. Since ultrasonic waves can produce high-frequency vibrations in liquids, they can effectively disperse particles or microparticles in solvents to achieve a uniformly dispersed state, and can also disperse particles uniformly in a short time. Therefore, monodisperse microspheres are dispersed in ethanol using ultrasonic waves in this step, and then the ethanol is evaporated to complete drying, ensuring the stability and integrity of the film.

[0056] Further, the hydrophilic filter membrane is any one of PTFE, PVDF, and cellulose filter membrane.

[0057] Further, the monodisperse microspheres are any one of silica and PMMA.

[0058] Further, the concentration of the monodisperse microspheres is 15-30%, and the dropwise addition amount is 4-7 μL per square centimeter.

[0059] Further, a photothermal material dispersion liquid is prepared and dropped onto the three-dimensional photonic crystal film to obtain a water evaporation functional layer, which includes:

[0060] S210: Disperse the photothermal material in ethanol and ultrasonicate until uniformly dispersed to obtain a photothermal material dispersion liquid;

[0061] S220: Drop the photothermal material dispersion liquid onto the surface of the three-dimensional photonic crystal film, heat and evaporate the ethanol to complete drying to obtain a water evaporation functional layer.

[0062] Specifically, the photothermal material is a type of material that can absorb solar energy and convert it into heat energy, usually with high light-to-heat conversion efficiency and stability. In this step, the photothermal material is uniformly dispersed in ethanol solvent to obtain a photothermal material dispersion liquid, which is added dropwise to the surface of the three-dimensional photonic crystal film to form a water evaporation functional layer with light-to-heat conversion function, thereby realizing water evaporation function. In addition, the purpose of heating and evaporating ethanol to complete drying is to remove the solvent and uniformly distribute the photothermal material on the surface of the photonic crystal film to form a stable water evaporation functional layer.

[0063] Further, the concentration of the photothermal material is 0.1-1%, the dropwise addition amount is 1-5 μL per square centimeter, and the heating temperature is 50-70°C.

[0064] Further, the thermal insulation foam is any one of EPE and PS foam.

[0065] Example Two:

[0066] As shown in Figure 3 The preparation system of the water evaporation structure based on the photonic bandgap effect, the system comprises:

[0067] Three-dimensional photonic crystal film manufacturing module: prepare a microsphere dispersion liquid, and manufacture a three-dimensional photonic crystal film through the microsphere dispersion liquid;

[0068] Water evaporation functional layer manufacturing module: manufacture a photothermal material dispersion liquid, and drop the photothermal material dispersion liquid on the three-dimensional photonic crystal film to obtain a water evaporation functional layer;

[0069] Water evaporation module: insert the edge of the water evaporation functional layer into the heat insulation foam, and float on the water surface to absorb sunlight to realize water evaporation.

[0070] The above adjustment system in the application can effectively realize the preparation method of the water evaporation structure based on the photonic bandgap effect, and the technical effects are as described in the above embodiments, which will not be repeated here.

[0071] Further, the three-dimensional photonic crystal film manufacturing module comprises:

[0072] Microsphere dispersion liquid obtaining unit: disperse monodisperse microspheres in ethanol, and ultrasonically until the microspheres are uniformly dispersed to obtain a microsphere dispersion liquid;

[0073] Hydrophilic filter membrane placing unit: take a hydrophilic filter membrane and horizontally place it on a table top;

[0074] Three-dimensional photonic crystal film obtaining unit: drop the microsphere dispersion liquid on the surface of the hydrophilic filter membrane, and evaporate ethanol at room temperature until complete drying to obtain a three-dimensional photonic crystal film.

[0075] Similarly, the above optimization scheme of the system can also correspondingly realize the optimization effects of the method in Embodiment 1, which will not be repeated here.

[0076] Although the present application is described in conjunction with specific features and embodiments thereof, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of the present application. Accordingly, the present specification and drawings are merely illustrative of the exemplary embodiments of the present application, and are considered to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the present application. Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the present application and its equivalents, the present application is intended to include these modifications and variations.

Claims

1. A method for preparing a water evaporation structure based on the photonic band gap effect, characterized in that, The method comprises: Disperse monodisperse microspheres in ethanol, ultrasonic until uniform dispersion, obtain microsphere dispersion liquid; take a hydrophilic filter membrane, horizontally placed on the table; take the microsphere dispersion liquid drops on the surface of the hydrophilic filter membrane, volatilize the ethanol at room temperature until completely dry, get three-dimensional photonic crystal film; Disperse photothermal material in ethanol, ultrasonic until uniform dispersion, obtain photothermal material dispersion liquid; take the photothermal material dispersion liquid drops on the surface of the three-dimensional photonic crystal film, heat and volatilize the ethanol until completely dry, get water evaporation functional layer; Insert the edge of the water evaporation functional layer into the thermal insulation foam, float on the water surface to absorb sunlight to realize water evaporation.

2. The method for preparing a water evaporation structure based on the photonic bandgap effect according to claim 1, characterized in that, The hydrophilic filter membrane is cellulose filter membrane.

3. The method for preparing a water evaporation structure based on the photonic bandgap effect according to claim 1, characterized in that, The monodisperse microspheres are any one of silica and PMMA.

4. The method for preparing a water evaporation structure based on the photonic bandgap effect according to claim 3, characterized in that, The concentration of the monodisperse microspheres is 15-30%, and the drop amount is 4-7 μL per square centimeter.

5. The method for preparing a water evaporation structure based on the photonic bandgap effect according to claim 1, characterized in that, The concentration of the photothermal material is 0.1-1%, and the drop amount is 1-5 μL per square centimeter, and the heating temperature is 50-70 ℃.

6. The method for preparing a water evaporation structure based on the photonic bandgap effect according to claim 1, characterized in that, The thermal insulation foam is any one of EPE and PS foam.

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