Self-floating photothermal conversion composite woven fabric with terry structure

Abstract

The invention provides a self-floating photothermal conversion composite woven fabric with a looped pile structure, which comprises an evaporation layer, a floating layer and a consolidation layer which are combined into a whole through double-warp-beam weaving, the evaporation layer and the consolidation layer have the same structure and are looped fabric layers made of hydrophilic fibers; the consolidation layer is used for being matched with the evaporation layer to fix the floating layer to form a stable composite woven fabric; the body warp yarns in the evaporation layer and the consolidation layer are provided by one warp beam, the wool warp yarns are provided by the other warp beam, and the warp yarns forming the evaporation layer and the consolidation layer are alternately positioned on the upper surface and the lower surface of the floating layer by means of surface and inner layer exchange tissues; the floating layer is composed of hydrophobic heat insulation foam. The photothermal conversion composite woven fabric provided by the invention has the characteristics of self-floating, salt deposition prevention, high evaporation efficiency, simple preparation process, cheap and easily available raw materials, environmental protection, industrial production and the like, can stably operate for a long time, and has important application prospects in the field of seawater desalination.

Description

Technical Field

[0001] The present invention relates to the fields of seawater desalination and photothermal conversion, and in particular to a self-floating photothermal conversion composite woven fabric with a terry structure. Background Art

[0002] The shortage of fresh water is one of the global problems restricting human development. Many countries and regions in the world are facing the problem of water shortage. Developing seawater desalination can obtain fresh water from the ocean, thus alleviating the problem of water resource tension.

[0003] In recent years, the solar interface evaporation seawater desalination technology has gradually attracted wide attention. This technology converts solar energy into heat energy, rapidly increasing the surface temperature of the material, thereby forming a local high-temperature region at the solid-liquid interface, promoting the rapid evaporation of water at this interface, and realizing seawater desalination.

[0004] Textiles have the characteristics of being soft, light, easy to process, and low in cost. Hydrophilic fabrics can construct a stable porous medium photothermal conversion interface by means of the capillary core absorption effect inside the fabric, and the microscopic and macroscopic structures of the evaporation interface are easy to control through the spinning and weaving process. Combining the fabric with hydrophobic thermal insulation foam materials can construct a fabric-based self-floating solar evaporator. With the heat insulation effect of the adiabatic foam layer, heat transfer to the seawater can be effectively inhibited, and through the thermal localization effect, efficient evaporation of the fabric interface can be achieved. There has been a patent report on inventing a photothermal conversion composite fabric that can be woven on a large scale through the design of the woven fabric structure (patent application number: 202211163001.9), but the yarns on its evaporation interface are closely attached to the foam, and the evaporation area of the yarns is limited, and the evaporation efficiency still needs to be improved. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-floating photothermal conversion composite woven fabric with a terry structure to solve at least one of the above technical problems existing in the prior art.

[0006] To solve the above technical problems, a self-floating photothermal conversion composite woven fabric with a terry structure provided by the present invention includes, in the cross-section of the photothermal conversion composite woven fabric: an evaporation layer at the top layer, a floating layer in the middle layer, and a consolidation layer at the bottom layer;

[0007] The evaporation layer is composed of ground warp yarns, pile warp yarns, and weft yarns made of hydrophilic fibers;

[0008] The ground warp yarns and the pile warp yarns are respectively conveyed by two warp beams with different warping amounts, and the pile warp yarns form a terry structure on the surfaces of the evaporation layer and the consolidation layer during the weaving process;

[0009] The warp yarns of the evaporation layer and the consolidation layer are alternately located on the upper surface and the lower surface of the floating layer by means of a warp-reverse weft change structure, surrounding the floating layer to form a photothermal conversion composite woven fabric.

[0010] The floating layer is composed of hydrophobic heat-insulating foam.

[0011] In the present invention, the evaporation layer is used to provide a photothermal conversion interface, and the consolidation layer is used to cooperate with the evaporation layer to consolidate the floating layer, forming a photothermal conversion composite woven fabric. The floating layer is made of hydrophobic heat-insulating foam, which can effectively block or weaken the heat conduction between the evaporation layer and the water body, thereby increasing the surface temperature and evaporation efficiency of the evaporation layer. The evaporation layer and the consolidation layer are made of hydrophilic fibers. The pile warp yarns and ground warp yarns constituting the evaporation layer and the consolidation layer are alternately located on the upper and lower surfaces of the floating layer by means of a warp-reverse weft change structure, providing liquid water for the evaporation layer by means of capillary action.

[0012] Furthermore, the density of the hydrophobic heat-insulating foam is less than the density of water, and it can not be deformed under the action of weaving tension.

[0013] The hydrophobic heat-insulating foam is made of materials with light weight, low density and poor hydrophilicity, so as to realize the self-floating load-bearing capacity of the photothermal conversion composite woven fabric.

[0014] The self-floating photothermal conversion composite woven fabric disclosed in the present application is composed of hydrophilic yarns and hydrophobic heat-insulating foam by composite weaving, and has self-floating property. The photothermal conversion interface of the photothermal conversion composite woven fabric is a terry fabric formed by weaving and covering the surface of the hydrophobic heat-insulating foam. The height of the terry is 1-5 mm, and the water evaporation efficiency ranges from 50% to 95% under the intensity of one sun's illumination, which can meet the requirement of long-term operation without salt accumulation for 15% high-concentration seawater desalination.

[0015] Preferably, the hydrophobic heat-insulating foam is preferably black.

[0016] Preferably, the hydrophobic heat-insulating foam is carefully made of EPE, which has the properties of heat preservation, heat insulation, corrosion resistance and anti-aging.

[0017] Furthermore, the contact angle of the hydrophilic fiber ranges from 0° to 90°.

[0018] More preferably, the hydrophilic fiber is black.

[0019] Furthermore, the hydrophilic fiber is a hydrophilic natural fiber or a chemical fiber subjected to surface hydrophilic modification treatment.

[0020] More preferably, the hydrophilic fiber is superfine denier or fine denier polypropylene, polyester or polyamide. The smaller the fineness of the hydrophilic fiber monofilament, the stronger the capillary wicking ability, providing finer inter-fiber capillary water and a larger capillary water heating specific surface area, which is beneficial to water evaporation.

[0021] Furthermore, the twist of the yarn used is 5 to 50 turns / 10 cm;

[0022] The fineness of the yarn used is 20 to 2000 D; alternatively, the fineness of the yarn used is 5 to 220 tex.

[0023] Preferably, the width of the hydrophobic heat-insulating foam is between 1 and 10 cm, and the thickness is preferably between 1 and 5 cm. More preferably, the width of the hydrophobic heat-insulating foam is 2 - 5 cm, and the thickness is 2 - 3 cm.

[0024] Furthermore, the ground warp yarn of the evaporation layer and the ground warp yarn of the consolidation layer are the same yarn, and the pile warp yarn of the evaporation layer and the pile warp yarn of the consolidation layer are the same yarn; after the evaporation layer and the consolidation layer are woven, the ground warp yarn and the pile warp yarn of the evaporation layer are turned over to the consolidation layer, and weft yarns are introduced to continue interweaving to form the consolidation layer; the ground warp yarn and the pile warp yarn of the consolidation layer are turned over to the evaporation layer, and weft yarns are introduced to continue interweaving to form the evaporation layer.

[0025] That is, during preparation, according to the fabric structure diagram, the threading method adopts the direct threading method, and the ground warp yarn, the pile warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. The ground warp yarn and the pile warp yarn are respectively conveyed by two warp beams with different let-off amounts. The pile warp yarn forms a loop structure on the surfaces of the evaporation layer and the consolidation layer during weaving, providing a larger evaporation area for the evaporation layer; the ground warp yarn forms the ground structure of the evaporation layer and the consolidation layer during weaving, consolidating the loops on the fabric surface. After the evaporation layer and the consolidation layer are woven to a set length, a hydrophobic heat-insulating foam is introduced, and then the pile warp yarn and the ground warp yarn of the evaporation layer and the consolidation layer are swapped by the inside-out layer organization and continue weaving. After multiple weaving cycles, the fabric is taken off the loom to obtain the above-mentioned self-floating photothermal conversion composite woven fabric with a loop structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of a self-floating photothermal conversion composite woven fabric with a loop structure provided in an embodiment of the present invention;

[0028] Figure 2 It is a photo of a self-floating photothermal conversion composite woven fabric with a loop structure floating on the water surface in an embodiment of the present invention;

[0029] Figure 3 It is the evaporation layer or consolidation layer of a self-floating photothermal conversion composite woven fabric with a terry structure in the embodiments of the present invention;

[0030] Among them, (3a) is a photo of the surface of a self-floating photothermal conversion composite woven fabric with a terry height of 1.5 mm, and (3b) is an electron microscope image of the terry on the fabric surface;

[0031] Figure 4 It is the evaporation layer or consolidation layer of a self-floating photothermal conversion composite woven fabric with a terry structure in the embodiments of the present invention;

[0032] Among them, (4a) is a photo of the surface of a self-floating photothermal conversion composite woven fabric with a terry height of 3 mm, and (4b) is an electron microscope image of the terry on the fabric surface;

[0033] Figure 5 It is the photothermal performance test diagram of a self-floating photothermal conversion composite woven fabric with a terry structure provided in the embodiments of the present invention;

[0034] Among them, (5a) is the absorption spectrum of the photothermal conversion composite woven fabric in the wavelength range of 250 - 2500 nm, weighted by the standard AM1.5 solar spectrum; (5b) is the heating curve of the dry photothermal conversion composite woven fabric under one sun illumination intensity; (5c) is the infrared thermal image of the dry photothermal conversion composite woven fabric after turning on and off the light; (5d) is the infrared thermal image of the photothermal conversion composite woven fabric in the wet state in the evaporation system;

[0035] Figure 6 It is the moisture evaporation performance test image of a self-floating photothermal conversion composite woven fabric with a terry structure provided in the embodiments of the present invention;

[0036] Among them, (6a) is the relationship diagram between the evaporation efficiency and evaporation rate of the photothermal conversion composite woven fabric under one sun illumination intensity; (6b) is the relationship diagram of the cyclic stability of the moisture evaporation rate of the photothermal conversion composite woven fabric under one sun illumination intensity;

[0037] Figure 7 It is a photo of the surface of a self-floating photothermal conversion composite woven fabric with a terry structure placed in a simulated high-concentration seawater (10 wt% NaCl solution) environment, after observing for 8 hours under one sun illumination intensity;

[0038] Among them, (7a) is a photo of the surface of the photothermal conversion composite woven fabric (1.5 - 1×1) (with a terry height of 1.5 mm, a hydrophobic thermal insulation foam width of 1 cm, and a thickness of 1 cm);

[0039] (7b) is a photograph of the surface of the photothermal conversion composite woven fabric (3 - 1×1) (the loop height is 3 mm, the width of the hydrophobic heat-insulating foam is 1 cm, and the thickness is 1 cm);

[0040] (7c) is a photograph of the surface of the photothermal conversion composite woven fabric (1.5 - 2×1) (the loop height is 1.5 mm, the width of the hydrophobic heat-insulating foam is 2 cm, and the thickness is 1 cm);

[0041] (7d) is a photograph of the surface of the photothermal conversion composite woven fabric (3 - 2×1) (the loop height is 3 mm, the width of the hydrophobic heat-insulating foam is 2 cm, and the thickness is 1 cm);

[0042] (7e) is a photograph of the surface of the photothermal conversion composite woven fabric (1.5 - 2×2) (the loop height is 1.5 mm, the width of the hydrophobic heat-insulating foam is 2 cm, and the thickness is 2 cm);

[0043] (7f) is a photograph of the surface of the photothermal conversion composite woven fabric (3 - 2×2) (the loop height is 3 mm, the width of the hydrophobic heat-insulating foam is 2 cm, and the thickness is 2 cm);

[0044] (7g) is a photograph of the surface of the photothermal conversion composite woven fabric (1.5 - 3×1) (the loop height is 1.5 mm, the width of the hydrophobic heat-insulating foam is 3 cm, and the thickness is 1 cm);

[0045] (7h) is a photograph of the surface of the photothermal conversion composite woven fabric (3 - 3×1) (the loop height is 3 mm, the width of the hydrophobic heat-insulating foam is 3 cm, and the thickness is 1 cm);

[0046] (7i) is a photograph of the surface of the photothermal conversion composite woven fabric (1.5 - 3×2) (the loop height is 1.5 mm, the width of the hydrophobic heat-insulating foam is 3 cm, and the thickness is 2 cm);

[0047] (7j) is a photograph of the surface of the photothermal conversion composite woven fabric (3 - 3×2) (the loop height is 3 mm, the width of the hydrophobic heat-insulating foam is 3 cm, and the thickness is 2 cm); Detailed implementation manners

[0048] The implementation schemes of the present invention will be described in detail below in conjunction with the embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments, the operations are carried out under conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.

[0049] The present invention will be further explained and illustrated below in conjunction with specific implementation manners.

[0050] Example 1

[0051] Referring to Figure 1 As shown, a self-floating photothermal conversion composite woven fabric with a terry structure provided in this embodiment has a cross-section composed of an evaporation layer (1) located at the top layer, a floating layer (2) located in the middle layer, and a consolidation layer (3) located at the bottom layer; the evaporation layer and the consolidation layer have the same structure and are composed of ground warp yarns (4)(8), pile warp yarns (6)(10), and weft yarns (5)(9); the warp yarns of the evaporation layer and the consolidation layer are alternately located on the upper surface and the lower surface of the floating layer by means of a surface and back layer-changing organization, surrounding the floating layer to form a photothermal evaporation composite woven fabric; the floating layer is composed of a hydrophobic heat-insulating foam (7).

[0052] In the present invention, the evaporation layer (1) is used to provide an evaporation interface, and the consolidation layer (3) is used to surround and consolidate the floating layer (2) with the evaporation layer (1). The floating layer (2) is made of a hydrophobic heat-insulating foam, which can effectively block the heat conduction between the evaporation layer and the water body, thereby greatly increasing the surface temperature of the evaporation layer and improving the evaporation efficiency of the evaporation layer (1). The evaporation layer (1) and the consolidation layer (3) are made of hydrophilic fibers, and the pile warp yarns and ground warp yarns constituting the evaporation layer (1) and the consolidation layer (3) are alternately located on the upper and lower surfaces of the floating layer, providing liquid water for the evaporation layer by means of capillary action.

[0053] More preferably, as Figure 1 shown, the photothermal conversion composite woven fabric is a surface and back layer-changing fabric woven by a double warp beam. The top layer is an evaporation layer (1) formed by the interweaving of ground warp yarns (4), pile warp yarns (6), and weft yarns (5), and the bottom layer is a consolidation layer (3) formed by the interweaving of ground warp yarns (8), pile warp yarns (10), and weft yarns (9). The pile warp yarns constituting the evaporation layer (1) and the consolidation layer (3) are transported by one warp beam with a large warp supply, and are interwoven with the weft yarns during the weaving process to form a terry structure on the surface of the fabric; the ground warp yarns constituting the evaporation layer (1) and the consolidation layer (3) are transported by another warp beam with a small warp supply, and are interwoven with the weft yarns during the weaving process to form a ground weave, which is used to fix the terry structure on the surface of the fabric, increase the evaporation area, and improve the evaporation efficiency.

[0054] The ground warp yarn (4) and the wool warp yarn (6) in the evaporation layer (1) are exchanged with the ground warp yarn (8) and the wool warp yarn (10) in the consolidation layer (3) at each set interval length, that is, the warp yarns are interchanged between the front and back layers; whenever the warp yarns are interchanged between the front and back layers, a hydrophobic heat-insulating foam (7) is introduced between the evaporation layer (1) and the consolidation layer (3) as the floating layer (2), which is used to lift the evaporation layer (1) to a set height, regulate the water content of the evaporation layer (1), and play a role in increasing the surface temperature and evaporation efficiency of the evaporation layer. All the yarns used are made of hydrophilic fibers. During use, the consolidation layer (3) sinks into the water. In this embodiment, the ground warp yarn (4) of the evaporation layer (1) and the ground warp yarn (8) of the consolidation layer (3) are essentially the same yarn, and the wool warp yarn (6) of the evaporation layer (1) and the wool warp yarn (10) of the consolidation layer (3) are essentially the same yarn. The warp yarn groups in the surface layer or the inner layer alternately extend into the inner layer or the surface layer. Similarly, the warp yarn groups in the inner layer or the surface layer alternately extend into the surface layer or the inner layer. Through capillary action, water to be evaporated is provided for the evaporation layer. The combination of the water-containing evaporation layer and the floating layer composed of the hydrophobic heat-insulating foam forms confined evaporation, effectively increasing the surface temperature and evaporation efficiency of the evaporation layer. The evaporation efficiency of this embodiment can be increased by 90%. During the working process, the salt content rate of the ground warp yarn (4) and the wool warp yarn (6) in the evaporation layer (1) increases after the water is evaporated, increasing the risk of salt accumulation on the surface of the evaporation layer (1), thereby affecting the subsequent water absorption performance and evaporation performance. In this embodiment, since the ground warp yarn (4) of the evaporation layer (1) and the ground warp yarn (8) of the consolidation layer (3) are essentially the same yarn, and the wool warp yarn (6) of the evaporation layer (1) and the wool warp yarn (10) of the consolidation layer (3) are essentially the same yarn, there is the same water pipeline inside, which helps the yarns to introduce the salt solution with a higher concentration in the evaporation layer (1) underwater and be fully diluted and released underwater, thus effectively solving the problem of salt accumulation.

[0055] Among them, the density of the hydrophobic heat-insulating foam (7) is less than the density of water, and it can not deform under the action of weaving tension, ensuring the stability and durability of the fabric. The hydrophobic heat-insulating foam is made of a hydrophobic material with a low density, providing the necessary floating bearing capacity for the photothermal conversion composite fabric.

[0056] The self-floating photothermal conversion composite fabric disclosed in this application is composed of hydrophilic yarns and hydrophobic heat-insulating foam by composite weaving, with self-floating property. The photothermal conversion interface of the photothermal conversion composite fabric is a terry fabric formed by weaving and covering the surface of the hydrophobic heat-insulating foam, and the water content of the photothermal conversion interface has controllability. The water evaporation efficiency range under one solar irradiance intensity is 50%-95%, which can meet the requirement of long-term operation without salt accumulation for 15% high-concentration seawater desalination.

[0057] Preferably, the hydrophobic heat-insulating foam (7) is preferably black. The hydrophobic heat-insulating foam (7) is carefully made of EPE, which has the properties of heat preservation, heat insulation, corrosion resistance and anti-aging. The selection of EPE provides strong support for the heat insulation and floating properties of the fabric.

[0058] Furthermore, the contact angle of the hydrophilic fiber ranges from 0° to 90°, effectively ensuring the conduction and distribution of moisture.

[0059] More preferably, the hydrophilic fiber is black.

[0060] Furthermore, the hydrophilic fiber is a hydrophilic natural fiber or a chemical fiber that has been surface hydrophilically modified to achieve an excellent water conduction effect.

[0061] Even more preferably, the hydrophilic fiber is superfine denier or fine denier polypropylene, polyester or nylon. The smaller the fineness of the hydrophilic fiber monofilament, the smaller the capillary water between the fibers, and the larger the specific surface area of the fiber for heating the capillary water, which is beneficial to the evaporation of moisture.

[0062] Furthermore, the twist of the yarn used is 5 to 50 turns / 10 cm.

[0063] The fineness of the yarn used is 20 to 2000 D; alternatively, the fineness of the yarn used is 5 to 220 tex.

[0064] Preferably, the width of the hydrophobic heat-insulating foam (7) is between 1 and 10 cm, and the thickness is preferably between 1 and 5 cm. Even more preferably, the width of the hydrophobic heat-insulating foam (7) is 2 - 5 cm, and the thickness is 2 - 3 cm.

[0065] During preparation, the ground warp yarns (4) of the evaporation layer (1) and the ground warp yarns (8) of the consolidation layer (3) are essentially the same yarn, and the pile warp yarns (6) of the evaporation layer (1) and the pile warp yarns (10) of the consolidation layer (3) are essentially the same yarn. That is, after the evaporation layer (1) and the consolidation layer (3) are woven, the ground warp yarns (4) and the pile warp yarns (6) of the evaporation layer (1) are both turned over to the consolidation layer (3), and weft yarns are introduced to continue interweaving with each other to form the consolidation layer (3). The ground warp yarns (4) and the pile warp yarns (6) of the consolidation layer (3) are both turned over to the evaporation layer (1), and weft yarns are introduced to continue interweaving with each other to form the evaporation layer (1). That is, according to the fabric structure diagram, the warp threading method adopts the direct threading method, and the ground warp yarns, the pile warp yarns and the weft yarns are interwoven with each other to form the evaporation layer (1) and the consolidation layer (3). The ground warp yarns and the pile warp yarns are respectively delivered by two warp beams with different warp feeding amounts. The pile warp yarns form the pile loop structures on the surfaces of the evaporation layer (1) and the consolidation layer (3) during the manufacturing process, and the ground tissues of the evaporation layer (1) and the consolidation layer (3) are formed by the pile warp yarns during the manufacturing process to fix the pile loop structures. When the evaporation layer (1) and the consolidation layer (3) complete the weaving of a set length, a hydrophobic heat-insulating foam is introduced. Then, the pile warp yarns and the ground warp yarns of the evaporation layer (1) and the consolidation layer (3) are swapped by means of the inside-out layer organization, and the weaving continues. After multiple weaving cycles, the fabric is taken off the loom to obtain the above-mentioned self-floating photothermal conversion composite woven fabric with a pile loop structure.

[0066] The present invention provides a self-floating photothermal conversion composite woven fabric with a pile loop structure, which uses the low density and non-crosslinked closed-cell structure of self-floating heat-insulating materials such as hydrophobic heat-insulating foam to provide the structural support for the photothermal conversion composite woven fabric, so that the photothermal conversion composite woven fabric can self-float on the water surface. At the same time, the heat-insulating performance of the hydrophobic heat-insulating foam can block the heat transfer from the evaporation interface to the water body, making the photothermal energy received by the surface of the evaporation layer (1) under light more concentrated, forming an efficient photothermal conversion interface and improving the evaporation performance of the evaporation layer (1). The pile loop structure formed by the pile warp yarns in the evaporation layer (1) greatly increases the evaporation area of liquid water, further significantly improving the evaporation efficiency of the photothermal conversion interface.

[0067] Meanwhile, the preparation method adopted for a self-floating photothermal conversion composite woven fabric with a terry structure provided by the present invention has significant advantages. The process is easy to operate, and the raw materials involved are not only low in price and easy to obtain, but also in line with the concept of green environmental protection, making large-scale production possible. In terms of the structure of the photothermal conversion composite woven fabric, it is made by an integrated weaving process between the support material and the yarns. This structure endows the photothermal conversion composite woven fabric with good mechanical properties and excellent flexible properties, featuring easy bending and folding and convenient winding and collection. At the same time, the photothermal conversion composite woven fabric has the properties of self-floating, good heat insulation, efficient moisture transfer and photothermal conversion, and can accurately regulate the moisture content and distribution. Based on these characteristics, under capillary action, the photothermal conversion composite woven fabric can form an efficient photothermal conversion interface, not only greatly improving the evaporation performance, but also being stable and reliable in performance during repeated use. It is worth mentioning that the continuous water-conducting channel design of the photothermal conversion composite woven fabric and the precise regulation of the moisture content and distribution enable the photothermal conversion composite woven fabric to excel in both evaporation performance and desalination performance. Given the above outstanding properties, the photothermal conversion composite woven fabric has broad application prospects in the fields of seawater desalination, sewage treatment, etc.

[0068] Example 2

[0069] This example is basically the same as Example 1, except that:

[0070] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a single fiber fineness of 1.5 D. The fineness of the polypropylene yarn is 1000 D / 650 F, and the twist is 30 turns / 10 cm. The densities of the ground warp yarns and the pile warp yarns are 300 pieces / 10 cm, and the density of the weft yarn is 120 pieces / 10 cm. By adjusting the amount of pile warp yarns fed by the double warp beams, the pile height of the evaporation layer and the consolidation layer is 1.5 mm. The floating layer uses black EPE, and the EPE is further cut into strip shapes with a width of 1 cm and a thickness of 1 cm. According to the fabric structure diagram, the threading method adopts the straight-through method. The ground warp yarns, pile warp yarns and weft yarns are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain extent, a hydrophobic heat-insulating foam is introduced as the floating layer, and the warp yarns constituting the evaporation layer are exchanged to the consolidation layer and the consolidation layer is exchanged to the evaporation layer through the inside-out layer structure, and new evaporation layer and consolidation layer are formed after multiple weavings. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, the above-mentioned self-floating photothermal conversion composite woven fabric with a terry structure is obtained.

[0071] Example 3

[0072] This example is basically the same as Example 2, except that:

[0073] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a fineness of 1.5 D per single fiber. The fineness of the polypropylene yarn is 1000 D / 650 F, and the twist is 45 twists / 10 cm. The density of the ground warp yarn and the pile warp yarn is 320 ends / 10 cm, and the density of the weft yarn is 150 picks / 10 cm. By adjusting the amount of pile warp yarn fed by the double warp beams, the pile height of the evaporation layer and the consolidation layer is 3 mm. The floating layer is made of black pearl cotton, and the pearl cotton is further cut into strip shapes with a width of 1 cm and a thickness of 1 cm. According to the fabric structure diagram, the threading method uses the straight-through method. The ground warp yarn, the pile warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain extent, a hydrophobic thermal insulation foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed, and the unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, the above-mentioned self-floating photothermal conversion composite woven fabric with a pile structure is obtained.

[0074] Example 4

[0075] This example is basically the same as Example 2, except that:

[0076] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a fineness of 2 D per single fiber. The fineness of the polypropylene yarn is 1000 D / 500 F, and the twist is 30 twists / 10 cm. The density of the ground warp yarn and the pile warp yarn is 300 ends / 10 cm, and the density of the weft yarn is 120 picks / 10 cm. By adjusting the amount of pile warp yarn fed by the double warp beams, the pile height of the evaporation layer and the consolidation layer is 1.5 mm. The floating layer is made of black pearl cotton, and the pearl cotton is further cut into strip shapes with a width of 1 cm and a thickness of 1 cm. According to the fabric structure diagram, the threading method uses the straight-through method. The ground warp yarn, the pile warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain extent, a hydrophobic thermal insulation foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed, and the unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, the above-mentioned self-floating photothermal conversion composite woven fabric with a pile structure is obtained.

[0077] Example 5

[0078] This example is basically the same as Example 2, except that:

[0079] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, and the fineness of a single fiber is 2D. The fineness of the polypropylene yarn is 800D / 400F, and the twist is 45 twists / 10 cm. The density of the ground warp yarn and the wool warp yarn is 320 ends / 10 cm, and the density of the weft yarn is 150 picks / 10 cm. By adjusting the amount of wool warp yarn fed by the double warp beam, the loop height of the evaporation layer and the consolidation layer is 3 mm. The floating layer uses black EPE, and the EPE is further cut into strip shapes. The width of the strip is 2 cm and the thickness is 1 cm. According to the fabric structure diagram, the threading method uses the direct threading method. The ground warp yarn, the wool warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain level, a hydrophobic heat-insulating foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, the above-mentioned self-floating photothermal conversion composite woven fabric with a loop structure is obtained.

[0080] Example 6

[0081] This example is basically the same as Example 2, except that:

[0082] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, and the fineness of a single fiber is 2D. The fineness of the polypropylene yarn is 1000D / 500F, and the twist is 45 twists / 10 cm. The density of the ground warp yarn and the wool warp yarn is 350 ends / 10 cm, and the density of the weft yarn is 150 picks / 10 cm. By adjusting the amount of wool warp yarn fed by the double warp beam, the loop height of the evaporation layer and the consolidation layer is 1.5 mm. The floating layer uses black EPE, and the EPE is further cut into strip shapes. The width of the strip is 3 cm and the thickness is 1 cm. According to the fabric structure diagram, the threading method uses the direct threading method. The ground warp yarn, the wool warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain level, a hydrophobic heat-insulating foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, the above-mentioned self-floating photothermal conversion composite woven fabric with a loop structure is obtained.

[0083] Example 7

[0084] This example is basically the same as Example 2, except that:

[0085] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a single fiber fineness of 1.5 D. The fineness of the polypropylene yarn is 900 D / 600 F, and the twist is 30 twists / 10 cm. The density of the ground warp and the wool warp is 300 ends / 10 cm, and the density of the weft yarn is 150 ends / 10 cm. By adjusting the amount of wool warp fed by the double warp beam, the loop height of the evaporation layer and the consolidation layer is 3 mm. The floating layer is made of black pearl cotton, and the pearl cotton is further cut into strip shapes. The width of the strip is 2 cm and the thickness is 2 cm. According to the fabric structure diagram, the threading method is the direct threading method. The ground warp, the wool warp and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain level, a hydrophobic heat-insulating foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, a self-floating photothermal conversion composite fabric with a loop structure as described above is obtained.

[0086] Example 8

[0087] This example is basically the same as Example 2, except that:

[0088] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a single fiber fineness of 2 D. The fineness of the polypropylene yarn is 900 D / 450 F, and the twist is 45 twists / 10 cm. The density of the ground warp and the wool warp is 320 ends / 10 cm, and the density of the weft yarn is 150 ends / 10 cm. By adjusting the amount of wool warp fed by the double warp beam, the loop height of the evaporation layer and the consolidation layer is 3 mm. The floating layer is made of black pearl cotton, and the pearl cotton is further cut into strip shapes. The width of the strip is 3 cm and the thickness is 1 cm. According to the fabric structure diagram, the threading method is the direct threading method. The ground warp, the wool warp and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain level, a hydrophobic heat-insulating foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layer and consolidation layer are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, a self-floating photothermal conversion composite fabric with a loop structure as described above is obtained.

[0089] Example 9

[0090] This example is basically the same as Example 2, except that:

[0091] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a single fiber fineness of 2D. The fineness of the polypropylene yarn is 900D / 450F, and the twist is 45 twists / 10 cm. The densities of the ground warp yarn and the wool warp yarn are 320 ends / 10 cm, and the density of the weft yarn is 150 picks / 10 cm. By adjusting the amount of wool warp yarn fed by the double warp beams, the loop height of the evaporation layer and the consolidation layer is 2 mm. The floating layer uses black pearl cotton, and the pearl cotton is further cut into strip shapes. The width of the strip is 2 cm and the thickness is 2 cm. According to the fabric structure diagram, the threading method uses the direct threading method. The ground warp yarn, the wool warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving lengths of the evaporation layer and the consolidation layer reach a certain extent, a hydrophobic thermal insulation foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layers and consolidation layers are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, a self-floating photothermal conversion composite woven fabric with a loop structure as described above is obtained.

[0092] Example 10

[0093] This example is basically the same as Example 2, except that:

[0094] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, with a single fiber fineness of 2D. The fineness of the polypropylene yarn is 1200D / 600F, and the twist is 30 twists / 10 cm. The densities of the ground warp yarn and the wool warp yarn are 300 ends / 10 cm, and the density of the weft yarn is 120 picks / 10 cm. By adjusting the amount of wool warp yarn fed by the double warp beams, the loop height of the evaporation layer and the consolidation layer is 3 mm. The floating layer uses black pearl cotton, and the pearl cotton is further cut into strip shapes. The width of the strip is 2 cm and the thickness is 2 cm. According to the fabric structure diagram, the threading method uses the direct threading method. The ground warp yarn, the wool warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving lengths of the evaporation layer and the consolidation layer reach a certain extent, a hydrophobic thermal insulation foam is introduced as the floating layer. With the help of the inside-out layer-changing structure, the warp yarns constituting the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, new evaporation layers and consolidation layers are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, a self-floating photothermal conversion composite woven fabric with a loop structure as described above is obtained.

[0095] Example 11

[0096] This example is basically the same as Example 2, except that:

[0097] The hydrophilic fibers of the evaporation layer and the consolidation layer are made of superfine denier polypropylene filament fibers, and the fineness of a single fiber is 2D. The fineness of the polypropylene yarn is 900D / 450F, and the twist is 45 turns / 10 cm. The densities of the ground warp yarn and the wool warp yarn are 350 pieces / 10 cm, and the density of the weft yarn is 150 pieces / 10 cm. By adjusting the amount of wool warp yarn fed by the double warp beam, the loop height of the evaporation layer and the consolidation layer is 2 mm. The floating layer is made of black pearl cotton, and the pearl cotton is further cut into strip shapes. The width of the strip is 3 cm and the thickness is 2 cm. According to the fabric structure diagram, the threading method adopts the direct threading method. The ground warp yarn, the wool warp yarn and the weft yarn are interwoven with each other to form the evaporation layer and the consolidation layer. After multiple cycles of weaving, when the weaving length of the evaporation layer and the consolidation layer reaches a certain level, a hydrophobic heat-insulating foam is introduced as the floating layer. With the help of the inside-out layer structure, the warp yarns forming the evaporation layer are exchanged to the consolidation layer, and the consolidation layer is exchanged to the evaporation layer. After multiple weavings, a new evaporation layer and a consolidation layer are formed. The unit interweaving structure diagram is shown in Figure 1. After getting off the loom after multiple weaving cycles, a self-floating photothermal conversion composite fabric with a loop structure as described above is obtained.

[0098] The following is the performance test of the prepared photothermal conversion composite fabric in seawater desalination.

[0099] (1) Thermal performance test

[0100] In order to characterize the light absorption efficiency of the self-floating photothermal conversion composite fabric with a loop structure, we used a UV-VIS-NIR spectrophotometer to measure the absorption spectrum of the photothermal conversion composite fabric. As Figure 5 shown in a, the absorbance of the photothermal conversion composite fabric with a loop structure in the wavelength range of 250 - 2500 nm is 98.2%, indicating its good light absorption performance. As Figure 5 shown in b and 5c, taking the photothermal conversion composite fabric (1.5 - 2×2) (the loop height is 1.5 mm, the width of the hydrophobic heat-insulating foam is 2 cm, and the thickness is 2 cm) as an example, an infrared camera was used to record its temperature and temperature distribution changing with time in the dry state. Under the irradiation of a solar irradiance, the surface temperature of the dry photothermal conversion composite fabric (1.5 - 2×2) rises rapidly, and the temperature reaches about 86.8℃ at 10 min ( Figure 5 b). As can be seen from Figure 5 c, during the illumination process of the evaporation layer of the photothermal conversion composite fabric (1.5 - 2×2), the flat part facing the light source heats up faster than the gap part between the planes. After turning off the light, due to mutual radiation between the gap parts between the planes, the heat preservation performance is better than that of the flat part, and the temperature drops more slowly than that of the flat part. This structure combining fast heating and slow cooling further improves the thermal performance of the photothermal conversion composite fabric. As Figure 5As shown in d, taking the photothermal conversion composite fabric (1.5 - 2×2) (with a loop height of 1.5 mm, a width of 2 cm, and a thickness of 2 cm for the hydrophobic thermal insulation foam) as an example, an infrared camera was used to record its temperature and temperature distribution over time in the wet state. Under the irradiation of one sun's light intensity, the surface temperature of the wet photothermal conversion composite fabric (1.5 - 2×2) rose rapidly, reaching about 27.3 °C at 2 min, and reaching 45.2 °C and being evenly distributed after 30 min. This indicates that the photothermal conversion composite fabric (1.5 - 2×2) with strong light absorption in the evaporation system can generate a relatively high surface temperature under one sun, and can transport an appropriate amount of water to the evaporation surface for local heating, thereby obtaining a higher evaporation rate and evaporation efficiency.

[0101] (2) Evaporation performance test

[0102] The evaporation efficiency and evaporation rate of the self - floating photothermal conversion composite fabric with a loop structure were further calculated, and the results are as Figure 6 shown in a. Under the irradiation of one sun's light intensity, compared with the evaporation of pure water, the evaporation efficiency and evaporation rate of 10 kinds of photothermal conversion composite fabrics were significantly improved. Among them, when the width of the hydrophobic thermal insulation foam was less than 2 cm, the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric with a loop height of 3 mm were higher than those of the photothermal conversion composite fabric with a loop height of 1.5 mm. When the width of the hydrophobic thermal insulation foam was greater than 2 cm, the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric with a loop height of 3 mm were lower than those of the photothermal conversion composite fabric with a loop height of 1.5 mm. When the width of the hydrophobic thermal insulation foam was equal to 2 cm, the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric (1.5 - 2×2) were the best, reaching 90.4% and 1.44 kgm -2 h -1 ⁻² respectively. When the thickness of the hydrophobic thermal insulation foam was equal to 1 cm, the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric (1×1) and the photothermal conversion composite fabric (2×1) increased with the increase of the loop height, while the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric (3×1) decreased with the increase of the loop height. When the thickness of the hydrophobic thermal insulation foam was equal to 2 cm, the evaporation efficiency and evaporation rate of the photothermal conversion composite fabric (2×2) and the photothermal conversion composite fabric (3×2) decreased with the increase of the loop height. The above results show that by adjusting the loop height of the photothermal conversion composite fabric, the width and thickness of the hydrophobic thermal insulation foam, the water content and water distribution of the photothermal conversion composite fabric can be adjusted, enabling the photothermal conversion composite fabric to achieve optimal water transfer, good thermal performance, and less heat loss, thereby obtaining the optimal evaporation efficiency.

[0103] The cyclic performance of the photothermal conversion composite fabric irradiated under one sun illumination intensity is an important indicator, and the results are as Figure 6 shown in (b). The photothermal conversion composite fabric (1.5 - 2×2) underwent 10 cyclic tests each exceeding 8 hours under one sun illumination intensity and still maintained an excellent and stable evaporation rate. The results indicate that the photothermal conversion composite fabric has excellent stability and durability and can operate for a long time.

[0104] (3) Anti - salt - deposition performance

[0105] Ten photothermal conversion composite fabrics were placed in simulated high - salinity seawater (10 wt% NaCl solution), and the surface photos of the fabrics after working for 8 hours under one sun illumination intensity were observed, as Figure 7 shown. The results show that only a small amount of salt deposition appeared on the surfaces of the photothermal conversion composite fabrics (3 - 2×2), (1.5 - 3×2), and (3 - 3×2), and the amount of salt deposition gradually increased with the increase in the height of the terry loops and the width of the hydrophobic thermal insulation foam. Since the increase in the height of the terry loops and the width of the hydrophobic thermal insulation foam will a. increase the diffusion distance of the high - concentration salt solution generated during evaporation to the water body, and at the same time b. increase the distance of the water - conducting path, resulting in a relatively low water content at the evaporation interface, both factors reduce the ion diffusion rate and gradually form salt precipitation. Therefore, regulating the height of the terry loops, the width and thickness of the hydrophobic thermal insulation foam of the photothermal conversion composite fabric is crucial for its anti - salt - deposition performance. The photothermal conversion composite fabric (1.5 - 2×2) has the best structural design and simultaneously has excellent evaporation efficiency and good anti - salt - deposition performance.

Claims

1. A self-floating photothermal conversion composite woven fabric with a terry structure, characterized in that, The photothermal conversion composite woven fabric is composed of hydrophilic fibers and hydrophobic heat-insulating foam, and its cross-section consists of an evaporation layer (1) located at the top layer, a floating layer (2) located in the middle layer, and a consolidation layer (3) located at the bottom layer; The evaporation layer and the consolidation layer have the same structure and are composed of ground warp yarns (4)(8), pile warp yarns (6)(10) and weft yarns (5)(9).

2. The photothermal conversion composite woven fabric according to claim 1, wherein The ground warp yarns and the pile warp yarns are respectively conveyed by two warp beams with different warp feeding amounts. The pile warp yarns form a loop structure on the surfaces of the evaporation layer and the consolidation layer during weaving, and the ground warp yarns are interwoven with the weft yarns to form a ground weave to fix the loops on the fabric surface.

3. The photothermal conversion composite woven fabric according to claim 1, wherein The loop structure is formed by the pile warp yarns, and the loop height is 1-5 mm.

4. The photothermal conversion composite woven fabric according to claim 1, wherein the warp yarns constituting the evaporation layer and the consolidation layer are alternately located on the upper surface and the lower surface of the floating layer by means of a face-to-back layer-changing organization, and the floating layer is surrounded to form the photothermal conversion composite woven fabric.

5. The photothermal conversion composite woven fabric according to claim 1, wherein The floating layer is composed of hydrophobic heat-insulating foam (7). The density of the hydrophobic heat-insulating foam is less than that of water, and it can maintain dimensional stability under the action of the weaving tension of the warp yarns. The color is preferably black, and the material is preferably EPE.

6. The photothermal conversion composite woven fabric according to claim 1, characterized in that, The contact angle of the hydrophilic fiber is in the range of 0°-90°, and the material is a hydrophilic natural fiber or a chemical fiber subjected to surface hydrophilic modification treatment, preferably superfine denier or fine denier polypropylene, polyester or nylon.

7. The photothermal conversion composite woven fabric according to claim 1, wherein The hydrophilic fiber is precisely selected as superfine denier or fine denier polypropylene, polyester or nylon.

8. The photothermal conversion composite woven fabric according to claim 1, wherein The twist of the yarn used is 5 to 50 turns / 10 cm; the fineness of the yarn used is 20 to 2000 D; or, the fineness of the yarn used is 5 to 220 tex.

9. The photothermal conversion composite woven fabric according to claim 1, wherein The width of the hydrophobic heat-insulating foam is between 1 and 10 cm, and the thickness is preferably between 1 and 5 cm.

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