Tubular evaporation fabric based on tungsten filament wrapped by graphene modified PVA yarn and preparation method of tubular evaporation fabric

Abstract

The invention provides a tubular evaporation fabric based on graphene modified PVA (Polyvinyl Alcohol) coated tungsten filaments and a preparation method of the tubular evaporation fabric. According to the tubular evaporation fabric, tungsten filaments 1 serve as core yarn, graphene modified PVA yarn 2 serves as an outer cladding layer, covering yarn is prepared through ring spinning, and then a hollow tubular structure is formed through weaving; the tungsten filament core yarn layer is a high-thermal-conductivity tungsten filament subjected to acid pickling and nickel layer sputtering treatment; the graphene modified PVA outer wrapping layer is quantitative roving made of graphene modified PVA short fibers, the tungsten filament core yarn and the graphene modified PVA outer wrapping layer are adopted to form a heat conduction / hydrophilic synergistic structure in cooperation with a hollow circular tube shape of a twill change structure, efficient photo-thermal evaporation performance is achieved, and evaporation efficiency reduction caused by local heat accumulation can be prevented; through the axial efficient heat conduction of the tungsten filament and the capillary water conveying capacity of the outer wrapping layer, heat can be guided to be evenly conducted, water can be directionally transmitted, salt crystal deposition in the high-salt environment is effectively avoided, and the high-salt-resistant tungsten filament composite membrane is suitable for seawater desalination and high-salt wastewater treatment scenes.

Description

Technical Field

[0001] This invention belongs to the field of functional textile materials and solar photothermal conversion technology, specifically relating to a tubular evaporation fabric made of graphene-modified PVA yarn wrapped with tungsten wire as warp and weft yarns and its preparation method, which is particularly suitable for high-velocity seawater desalination, vertical permeation evaporation and gradient concentration wastewater treatment scenarios. Background Technology

[0002] Existing planar evaporation fabrics have two major limitations: first, the evaporation surface area is limited by the planar dimensions, making it difficult to improve the evaporation efficiency per unit volume; second, the steam escapes in a disordered direction, easily forming condensation and reflux on the fabric surface. In the patent with publication number CN118754235A, a tubular structure woven from pure graphene-modified PVA yarn can enhance the directional discharge of steam through axial channels, but tubular fabrics woven from a single fiber suffer from uneven heat conduction and insufficient water transport capacity.

[0003] When applying graphene-modified PVA tungsten-coated core-spun yarn to tubular fabrics, three key issues need to be addressed: first, the radial-axial coordinated design of the tungsten filament heat conduction network in the tubular structure to prevent heat loss to the external environment; second, the size control of the tubular channels formed by the interlacing of warp and weft yarns to ensure that the capillary water transport rate matches the evaporation rate. Currently, there is no relevant technical solution for making tubular evaporation fabrics from this type of core-spun yarn. Summary of the Invention

[0004] This invention aims to solve the problems of limited efficiency of planar evaporation fabrics and poor synergy between heat conduction and water transport in traditional tubular fabrics. It provides a tubular evaporation fabric with tungsten wire wrapped in graphene-modified PVA yarn as warp and weft yarns. Through the coupling of tubular structure and core-spun yarn properties, the evaporation area is doubled, steam is directionally discharged, and heat is radially confined and utilized.

[0005] To achieve the above objectives, the present invention provides a tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire, which is woven in a tubular manner using graphene-modified PVA / tungsten wire core-spun yarn as warp and weft yarns.

[0006] In some preferred technical solutions, the evaporation fabric is a hollow circular tube structure with a tube diameter of 5-10 mm.

[0007] In some technical solutions, both the warp and weft yarns are graphene-modified PVA / tungsten filament core-spun yarn 3 with a fineness of 20-40 tex.

[0008] In some preferred embodiments, the warp and weft yarns are 20-30 tex graphene-modified PVA / tungsten wire core-spun yarn 3; the tungsten wire 1 has a diameter of 0.05-0.1 mm, including 0.05, 0.06, 0.07, 0.08, 0.09, and 0.1 mm, and a contact resistance of <10 Ω·cm.-4 Ωcm 2 .

[0009] In some technical solutions, the number of warp yarns is 4-64 to achieve better wicking and water transfer capabilities. Preferably, the number of warp yarns used is 8-20.

[0010] In some preferred technical solutions, the weft yarn density is 100-250 yarns / 10cm, including 100, 120, 140, 160, 180, 200, 220, 240, and 250 yarns / 10cm, and the tube wall adopts a twill weave to form a spiral pore channel.

[0011] The tubular evaporation fabric contains tungsten filaments forming a three-dimensional heat conduction network with an axial thermal conductivity ≥150W / (m K) and a radial thermal conductivity ≥80W / (m K).

[0012] In some preferred technical solutions, the tubular fabric has a length of 1 cm or more, including but not limited to 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 cm. When the length is greater than 5 cm, it can not only obtain energy from the environment using its side surface, but also utilize the high thermal conductivity of the tungsten wire to effectively conduct the heat generated at the top downwards, thereby heating the water in the area of ​​the tubular fabric that is not exposed to light. Preferably, the length of the tubular fabric is selected as 5-12 cm.

[0013] Furthermore, the method for preparing tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire includes at least the following steps:

[0014] Step 1: Core yarn pretreatment: Select tungsten wire 1 with a diameter of 0.05-0.1mm (purity ≥99.9%), ultrasonically clean it with 10% dilute hydrochloric acid to remove the oxide layer, then deposit a 5-10nm thick nickel layer by magnetron sputtering, and dry it at 80℃ under nitrogen protection to ensure that the thermal conductivity interface contact resistance is <10 Ω. -4 Ω·cm 2 ;

[0015] Step 2: Core-spun yarn preparation. Select tungsten wire 1 with a diameter of 0.05-0.1mm, and use it as core yarn after pretreatment. Make roving 2 with 6-8g / 10m of graphene-modified PVA short fiber, and use it as outer yarn. Use ring spinning equipment to spin the core yarn and roving into graphene-modified PVA / tungsten wire core-spun yarn 3 with a fineness of 20-40tex, ensuring that the tungsten wire axis deviation is ≤0.02mm.

[0016] Step 3: Tubular weaving, using a semi-automatic loom, the warp yarns are threaded into the heddle eyes of the loom, the number of warp yarns is 4-64, the weft yarns are wound by an automatic winding machine to prepare for the subsequent manual weft insertion, the weft density is 100-250 yarns / 10cm, the weaving tension of the weft yarn is 10±5cN, and a twill variation structure is used to form spiral pores.

[0017] In some preferred technical solutions, during ring spinning, the tungsten wire tension is controlled at 5-8 cN, the roving is drafted at 5-7 times, and the twist is 800-1000 twists / m.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. This invention weaves graphene-modified PVA / tungsten wire core-spun yarn into a spiral tubular fabric. The rigid support of the tungsten wire and the hydrophilicity of PVA form a reinforced capillary water transport channel, which improves the water transport rate compared with traditional tubular fabrics. At the same time, the gradient pores of the tube wall increase the specific surface area, which significantly enhances the water evaporation rate.

[0020] 2. The tubular fabric adopts a core-spun yarn structure of "deposited nickel-layered tungsten wire core material + graphene-modified PVA outer layer". The nickel layer avoids the heat concentration problem of pure tungsten wire and achieves efficient transmission of photothermal energy through the high conductivity of nickel. At the same time, the high thermal conductivity of tungsten wire and the hydrophilic network of PVA form a synergistic system of "photothermal-conductivity-water transport". It achieves more than 95% light absorption through graphene and uniformly conducts heat to the entire tube wall with the help of tungsten wire, avoiding water transport interruption caused by local overheating. The water transport efficiency is improved compared with single fiber fabrics.

[0021] 3. The tubular fabric utilizes the composite effect of graphene-modified PVA fiber and tungsten wire. The near-infrared light absorption performance of graphene and the heat directional conduction ability of tungsten wire form a synergistic photothermal conversion system, which has excellent photothermal conversion efficiency and significantly accelerates the moisture transfer speed and evaporation rate.

[0022] 4. Based on the design of the tubular evaporation fabric, when water is transported upward along the spiral channel, the evaporation of water causes the salt ion concentration to increase with height. The temperature gradient formed by the tungsten wire network promotes the diffusion of salt ions to the low concentration area. By adjusting the diameter, height and spiral angle of the tubular fabric, the salt ions can achieve migration equilibrium during the evaporation process, thus solving the salt blockage problem of traditional evaporation materials. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the molding process of the graphene-modified PVA / tungsten wire core-spun yarn of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the graphene-modified PVA / tungsten filament core-spun yarn of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of the tubular fabric of graphene-modified PVA / tungsten filament core-spun yarn of the present invention.

[0027] 1. Tungsten wire, 2. Graphene-modified PVA roving, 3. Graphene-modified PVA / tungsten wire core-spun yarn Detailed Implementation

[0028] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. These described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] Example 1

[0030] A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire and its preparation method are disclosed, comprising a single tubular evaporation fabric body. The tubular evaporation fabric body is woven from graphene-modified PVA / tungsten wire core-spun yarn using a semi-automatic machine.

[0031] The tubular evaporation fabric has a hollow cylindrical structure with a diameter of 7 mm and a length of 5 cm; it adopts a twill weave with a weft density of 180 threads / 10 cm.

[0032] The preparation of core-spun yarn includes the following steps:

[0033] Step 1: Tungsten wire pretreatment: Immerse 0.08mm tungsten wire 1 in 10% dilute hydrochloric acid, ultrasonically clean at 300W for 15 minutes, rinse with deionized water 3 times, and dry in nitrogen atmosphere at 80℃ for 2 hours; deposit an 8nm nickel layer by magnetron sputtering at 100W sputtering power for 3 minutes.

[0034] Step 2: Ring spinning yarn, setting the tungsten wire tension to 6cN, the modified PVA roving 2 (7g / 10m basis weight) is stretched 6 times, and the twist is 900 twists / m to obtain 30tex core-spun yarn 3 with a tungsten wire axis deviation of 0.01mm.

[0035] The weaving of tubular fabrics includes the following steps:

[0036] Step 1: Using a semi-automatic loom, manually thread the 16 core-spun yarns into the warp yarns;

[0037] Step 2: Manually insert the weft yarn, with a weft tension of 10cN and a weft density of 180 yarns / 10cm. Input the weave pattern diagram into the computer.

[0038] Step 3: Weave a tubular fabric with a length of 5cm.

[0039] Example 2

[0040] A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire and its preparation method are disclosed, comprising a single tubular evaporation fabric body. The tubular evaporation fabric body is woven from graphene-modified PVA / tungsten wire core-spun yarn using a semi-automatic machine.

[0041] The tubular evaporation fabric has a hollow cylindrical structure with a diameter of 7 mm and a length of 5 cm; it adopts a twill weave with a weft density of 180 threads / 10 cm.

[0042] The preparation of core-spun yarn includes the following steps:

[0043] Step 1: Tungsten wire pretreatment: Immerse 0.06mm tungsten wire 1 in 10% dilute hydrochloric acid, ultrasonically clean at 300W for 15 minutes, rinse with deionized water 3 times, and dry in nitrogen atmosphere at 80℃ for 2 hours; deposit an 8nm nickel layer by magnetron sputtering at a sputtering power of 100W for 3 minutes.

[0044] Step 2: Ring spinning yarn, setting the tungsten wire tension to 6cN, the modified PVA roving 2 (7g / 10m basis weight) is stretched 6 times, and the twist is 900 twists / m to obtain 30tex core-spun yarn 3 with a tungsten wire axis deviation of 0.01mm.

[0045] The weaving of tubular fabrics includes the following steps:

[0046] Step 1: Using a semi-automatic loom, manually thread the 16 core-spun yarns into the warp yarns;

[0047] Step 2: Manually insert the weft yarn, with a weft tension of 10cN and a weft density of 180 yarns / 10cm. Input the weave pattern diagram into the computer.

[0048] Step 3: Weave a tubular fabric with a length of 5cm.

[0049] Example 3

[0050] A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire and its preparation method are disclosed, comprising a single tubular evaporation fabric body. The tubular evaporation fabric body is woven from graphene-modified PVA / tungsten wire core-spun yarn using a semi-automatic machine.

[0051] The tubular evaporation fabric has a hollow cylindrical structure with a diameter of 7 mm and a length of 5 cm; it has a twill weave with a weft density of 180 threads / 10 cm.

[0052] The preparation of core-spun yarn includes the following steps:

[0053] Step 1: Tungsten wire pretreatment: Immerse 0.1mm tungsten wire 1 in 10% dilute hydrochloric acid, ultrasonically clean at 300W for 15 minutes, rinse with deionized water 3 times, and dry in nitrogen atmosphere at 80℃ for 2 hours; deposit an 8nm nickel layer by magnetron sputtering at a sputtering power of 100W for 3 minutes.

[0054] Step 2: Ring spinning yarn, setting the tungsten wire tension to 6cN, the modified PVA roving 2 (7g / 10m basis weight) is stretched 6 times, and the twist is 900 twists / m to obtain 30tex core-spun yarn 3 with a tungsten wire axis deviation of 0.01mm.

[0055] The weaving of tubular fabrics includes the following steps:

[0056] Step 1: Using a semi-automatic loom, manually thread the 16 core-spun yarns into the warp yarns;

[0057] Step 2: Manually insert the weft yarn, with a weft tension of 10cN and a weft density of 180 yarns / 10cm. Input the weave pattern diagram into the computer.

[0058] Step 3: Weave a tubular fabric with a length of 5cm.

[0059] Example 4

[0060] A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire and its preparation method are disclosed, comprising a single tubular evaporation fabric body. The tubular evaporation fabric body is woven from graphene-modified PVA / tungsten wire core-spun yarn using a semi-automatic machine.

[0061] The tubular evaporation fabric has a hollow cylindrical structure with a diameter of 7 mm and a length of 5 cm; it has a twill weave with a weft density of 180 threads / 10 cm.

[0062] The preparation of core-spun yarn includes the following steps:

[0063] Step 1: Tungsten wire pretreatment: Immerse 0.08mm tungsten wire 1 in 10% dilute hydrochloric acid, ultrasonically clean at 300W for 15 minutes, rinse with deionized water 3 times, and dry in nitrogen atmosphere at 80℃ for 2 hours; deposit an 8nm nickel layer by magnetron sputtering at 100W sputtering power for 3 minutes.

[0064] Step 2: Ring spinning yarn, setting the tungsten wire tension to 6cN, the modified PVA roving 2 (6.5g / 10m basis weight) is stretched 5 times, and the twist is 800 twists / m to obtain 28tex core-spun yarn 3 with a tungsten wire axis deviation of 0.01mm.

[0065] The weaving of tubular fabrics includes the following steps:

[0066] Step 1: Using a semi-automatic loom, manually thread the 16 core-spun yarns into the warp yarns;

[0067] Step 2: Manually insert the weft yarn, with a weft tension of 10cN and a weft density of 180 yarns / 10cm. Input the weave pattern diagram into the computer.

[0068] Step 3: Weave a tubular fabric with a length of 5cm.

[0069] Example 5

[0070] A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire and its preparation method are disclosed, comprising a single tubular evaporation fabric body. The tubular evaporation fabric body is woven from graphene-modified PVA / tungsten wire core-spun yarn using a semi-automatic machine.

[0071] The tubular evaporation fabric has a hollow cylindrical structure with a diameter of 7 mm and a length of 5 cm; it has a twill weave with a weft density of 180 threads / 10 cm.

[0072] The preparation of core-spun yarn includes the following steps:

[0073] Step 1: Tungsten wire pretreatment: Immerse 0.08mm tungsten wire 1 in 10% dilute hydrochloric acid, ultrasonically clean at 300W for 15 minutes, rinse with deionized water 3 times, and dry in nitrogen atmosphere at 80℃ for 2 hours; deposit an 8nm nickel layer by magnetron sputtering at 100W sputtering power for 3 minutes.

[0074] Step 2: Ring spinning yarn, setting the tungsten wire tension to 6cN, the modified PVA roving 2 (7.5g / 10m basis weight) is stretched 7 times, and the twist is 1000 twists / m to obtain 32tex core-spun yarn 3 with a tungsten wire axis deviation of 0.01mm.

[0075] The weaving of tubular fabrics includes the following steps:

[0076] Step 1: Using a semi-automatic loom, manually thread the 16 core-spun yarns into the warp yarns;

[0077] Step 2: Manually insert the weft yarn, with a weft tension of 10cN and a weft density of 180 yarns / 10cm. Input the weave pattern diagram into the computer.

[0078] Step 3: Weave a tubular fabric with a length of 5cm.

[0079] Example 6: The only difference from Example 1 is that the length of the tubular fabric is 6 cm.

[0080] Example 7: The only difference from Example 1 is that the length of the tubular fabric is 8 cm.

[0081] Example 8: The only difference from Example 1 is that the length of the tubular fabric is 10 cm.

[0082] Example 9: The only difference from Example 1 is that the length of the tubular fabric is 12 cm.

[0083] Comparative Example 1: The only difference from Example 1 is that pure graphene-modified PVA yarn was used as warp and weft yarns in the preparation process, resulting in a comparative photothermal evaporator.

[0084] Performance testing and characterization:

[0085] 1. Photothermal conversion performance test: The surface of the core-spun tubular fabric evaporator is irradiated with simulated sunlight (xenon lamp) system. The evaporator surface undergoes photothermal conversion, and the temperature rises. The temperature change is recorded at fixed intervals using an infrared thermal imager.

[0086] 2. Water evaporation rate test: The process of a solar steam generator was simulated using a container filled with simulated seawater. The experiment was conducted at a room temperature of approximately 25±5℃ and a humidity of approximately 40±5%. The solar intensity measurement point was located at the very top of the tubular fabric.

[0087] Test results explanation:

[0088] 1. Performance test results of the examples and comparative examples

[0089]

[0090] The water evaporation rate test results of Examples 1-9 and Comparative Example 1 show that the photothermal evaporator prepared using graphene-modified PVA yarn as warp and weft yarn provided by this invention has an excellent water evaporation rate. Pure graphene-modified PVA yarn has strong hydrophilicity, and the rapid evaporation of surface water carries away a large amount of heat, resulting in a top temperature of only 32.1℃ (far lower than the example containing tungsten wire). However, due to the lack of highly thermally conductive tungsten wire, heat cannot be conducted downwards through the fabric (conduction distance is only 0.2cm), relying solely on the top water for evaporation, while the water below evaporates only by absorbing heat from the environment, ultimately resulting in the lowest evaporation rate. However, with the addition of tungsten wire, the tungsten wire acts as a heat conduction channel, transferring the absorbed light and heat from the surface downwards through the fabric (conduction distance 4.0-10.2cm), making the heat distribution more uniform. This avoids the "heat waste" (excessive heat carried away by evaporating water) seen in Comparative Example 1, prevents localized overheating, stabilizes the top temperature, and ultimately achieves a higher evaporation rate.

[0091] Finally, it should be noted that although the present invention has been described in detail above with general descriptions and specific embodiments, the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire, characterized in that, The tubular evaporation fabric is woven from graphene-modified PVA / tungsten filament core-spun yarn 3 as warp and weft yarns in a tubular structure, with a tube diameter of 5-10 mm. The graphene-modified PVA / tungsten filament core-spun yarn has tungsten filament 1 as the core yarn and graphene-modified PVA yarn 2 as the outer sheath. The tungsten filaments in the tubular evaporation fabric form a three-dimensional heat conduction network, conducting heat along the axial and radial directions.

2. The tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire according to claim 1, characterized in that, Both the warp and weft yarns are graphene-modified PVA / tungsten wire core-spun yarns with a fineness of 20-40 tex; the tungsten wire has a diameter of 0.05-0.1 mm and a contact resistance of <10 Ω·cm. -4 Ωcm 2 .

3. The tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire according to claim 1, characterized in that, The weft yarn density is 100-250 yarns / 10cm, and the tube wall adopts a twill weave to form a spiral pore channel.

4. A method for preparing a tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire, characterized in that, At least the following steps are included: Step 1: Core yarn pretreatment: Select tungsten wire 1 with a diameter of 0.05-0.1mm (purity ≥99.9%), ultrasonically clean it with 10% dilute hydrochloric acid to remove the oxide layer, then deposit a 5-10nm thick nickel layer by magnetron sputtering, and dry it at 80℃ under nitrogen protection to ensure that the thermal conductivity interface contact resistance is <10 Ω. -4 Ω·cm 2 ; Step 2: Core-spun yarn preparation. Select tungsten wire 1 with a diameter of 0.05-0.1mm, and use it as core yarn after pretreatment. Make graphene-modified PVA short fiber into roving 2 with a basis weight of 6-8g / 10m, and then use it as outer yarn. Use ring spinning equipment to spin the core yarn and roving into graphene-modified PVA / tungsten wire core-spun yarn 3 with a fineness of 20-40tex, ensuring that the tungsten wire axis deviation is ≤0.02mm. Step 3: Tubular weaving, using a semi-automatic loom, the warp yarns are threaded into the heddle eyes of the loom, the number of warp yarns is 4-64, the weft yarns are wound by an automatic winding machine to prepare for the subsequent manual weft insertion, the weft density is 100-250 yarns / 10cm, the weaving tension of the weft yarn is 10±5cN, and a twill variation structure is used to form spiral pores.

5. The method for preparing tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire according to claim 4, characterized in that, The nickel layer deposited on the surface of the tungsten wire in step 1 avoids the heat concentration problem of pure tungsten wire and achieves efficient transmission of photothermal energy through the high conductivity of nickel.

6. The method for preparing tubular evaporation fabric based on graphene-modified PVA yarn wrapped with tungsten wire according to claim 4, characterized in that, In step 2, during ring spinning, the tungsten wire tension is controlled at 5-8 cN, the roving draft is 5-7 times, and the twist is 800-1000 twists / m.

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