Optical heat composite yarn and preparation method and application thereof

Abstract

The present application belongs to the field of photothermal fabric, and particularly relates to a photothermal composite yarn and a preparation method and application thereof. Carbon material is dissolved in a solvent to obtain a dispersion or slurry, and then the roving is impregnated and sized to ensure that the carbon material is embedded in the yarn. The obtained photothermal yarn and hydrophilic yarn can be drawn and twisted according to a certain mixing ratio to obtain a composite yarn. By adjusting the concentration of the carbon material dispersion and the mixing ratio of the yarn, the heating rate and evaporation efficiency of the photothermal fabric can be adjusted. The manufactured photothermal composite yarn is used to prepare a woven fabric or a knitted fabric, and a specific effect is achieved through fabric organizational structure design. The hydrophilic part promotes the rapid diffusion of sweat, and the photothermal part uses the heat generated by outdoor sunlight to keep the body warm. The air-permeable design allows steam and sweat to be quickly discharged after evaporation, reducing local humidity and air saturation, thereby ensuring evaporation efficiency and wearing comfort.

Description

Technical Field

[0001] This invention belongs to the field of photothermal fabrics, specifically relating to a photothermal composite yarn, its preparation method, and its application. Background Technology

[0002] With population growth and increasing water pollution, freshwater scarcity has become a global problem. Traditional seawater desalination technologies, such as reservoir osmosis, electrodialysis, and membrane distillation, require external power sources and suffer from high energy consumption and costs. This makes them unsuitable for operation in harsh and complex environmental conditions.

[0003] Cold regions face the challenge of staying warm in extreme climates, posing a significant threat to the survival and health of workers in these areas. Traditional clothing acts as an insulation layer by reducing heat conduction and convection. However, increasing the thickness of fabrics and the number of layers reduces breathability and moisture permeability, disrupts the moisture balance of the microclimate, and affects warmth retention and wearing comfort. Therefore, passive water treatment and personal warmth management are crucial.

[0004] Solar energy, as an inexhaustible and renewable clean energy source, has the potential to achieve zero-energy, low-cost seawater desalination through efficient utilization of solar energy. Simultaneously, solar thermal fabrics can convert solar energy into heat, achieving the purpose of heat storage and insulation.

[0005] Integrated and rigid solar evaporation devices suffer from drawbacks such as poor flexibility, fragility, and difficulty in transportation. In contrast, textile-based solar evaporation devices can effectively convert clean, free solar energy into heat energy for seawater desalination and wastewater purification, offering portability, operability, adaptability, and high efficiency.

[0006] Traditional solar thermal fabrics often employ coating processes, which suffer from problems such as unstable load-bearing capacity, clogging of pores by the solar thermal material affecting steam dissipation, and inability to regulate water supply and evaporation rates. Solar thermal fabrics, on the other hand, offer strong controllability, high wearing comfort, and promote rapid sweat wicking. They utilize heat converted from sunlight to retain body warmth, thus protecting the lives and health of workers in cold regions.

[0007] Invention patent CN106149147A discloses a method for producing a heat-retaining and heat-generating bulky double-layer structured woven fabric. First, a blended yarn of heat-retaining and heat-generating fiber / regenerated cellulose fiber is selected as the warp yarn, and a blended yarn of heat-retaining and heat-generating fiber / regenerated cellulose fiber / high-shrinkage acrylic / water-soluble vinylon (four-in-one blended bulky double-layer structure) is used as the weft yarn. A double-layered fabric structure is then woven using a double-weft weave structure. However, this fabric only has a heat-retaining function. Besides providing additional heat to the body in a timely manner, the fabric also needs to evaporate sweat produced by the body promptly to keep the body dry, thus ensuring both comfort and warmth.

[0008] Invention patent CN114457584A discloses a method for preparing and applying a carbon material single-sided coated fabric. The method involves uniformly coating a carbon material dispersion onto a fabric base to obtain a carbon material single-sided coated fabric for interfacial photothermal evaporation. However, this method uses a drop-coating process, making it difficult to precisely control the ratio of photothermal rate to evaporation rate. Furthermore, the carbon material is prone to falling off the fabric base, affecting the durability of the photothermal fabric.

[0009] Chinese invention patent CN114702093A discloses a method for preparing a three-dimensional porous salt-barrier interface evaporator using carbon nanotube-modified polyurethane sponge. A photothermal conversion layer is prepared by spraying a composite dispersion of carbon nanotubes and polydimethylsiloxane onto the surface of a polyurethane sponge. The reverse side of the photothermal conversion layer is then hydrophilically modified by spraying and dipping with polyvinyl alcohol, resulting in a three-dimensional porous interface evaporator. However, this 3D structure evaporator is bulky and lacks flexibility, making it difficult to meet the requirements for easy transportation in practical applications. Summary of the Invention

[0010] To address the aforementioned technical problems, this invention provides a method for preparing a photothermal composite yarn, comprising the following steps:

[0011] S1: Prepare carbon material dispersion and carbon material slurry respectively;

[0012] The carbon material dispersion includes carbon material and a dispersion medium, and the carbon material slurry includes carbon material, a binder, and a solvent.

[0013] S2: The roving is treated with a carbon material dispersion and then dried to obtain treated roving; the roving is Tencel, cotton or linen.

[0014] S3: The treated roving is stretched and twisted to obtain a composite yarn;

[0015] S4: The composite yarn is sized, dried, and wound to obtain a photothermal yarn; the sizing agent used is the carbon material sizing agent.

[0016] S5: The hydrophilic yarn and the photothermal yarn are drawn together and twisted twice to obtain the photothermal composite yarn.

[0017] Preferably, the carbon material is graphene, graphene oxide (GO), carbon nanotubes (CNT), or carbon black.

[0018] Preferably, in both the carbon material dispersion and the carbon material slurry, the mass ratio of carbon material to dispersion medium is 0.1-2:100.

[0019] Preferably, the dispersion medium and solvent are both water, dimethylformamide, or dimethyl sulfoxide.

[0020] Preferably, in the carbon material slurry, the mass ratio of adhesive to solvent is 5-15:100.

[0021] Preferably, the adhesive is thermoplastic polyurethane, purchased from LUBRIZOL Ltd.

[0022] Preferably, in step S3, the twist during stretching and twisting is 60-120T / 10cm.

[0023] Preferably, in step S3, ring spinning technology is used during drafting and twisting.

[0024] Preferably, in step S3, during the drafting and twisting process, the drafting ratio is 35-40, the twisting coefficient is 350-380, and the yarn count is 10-50 tex.

[0025] Preferably, in step S4, the sizing speed is 20-30 m / min.

[0026] Preferably, in step S4, the drying temperature is 40-60℃.

[0027] Preferably, in step S5, the twist of the sliver double twist is 20-80T / 10cm.

[0028] Preferably, in step S5, the ratio of the number of hydrophilic yarns to the number of light-heat yarns is 1-3:1-3.

[0029] By adjusting the concentration of the carbon material dispersion and the yarn mixing ratio, the heating rate and evaporation efficiency of the photothermal fabric can be controlled. Therefore, regulating the dynamic balance of heat and water supply holds promise for achieving efficient energy utilization. Continuous horizontal salt flow and diffusion prevent the deposition of salt particles and impurity ions, thereby improving durability and ion removal efficiency.

[0030] Preferably, in step S5, the winding rate of the doubling twist is 10-40 m / min.

[0031] The present invention also provides a photothermal composite yarn prepared by the above preparation method.

[0032] The present invention also provides a graphene oxide-loaded photothermal fabric, which is prepared using the above-mentioned photothermal composite yarn.

[0033] Preferably, the graphene oxide-loaded photothermal fabric is obtained by weaving or knitting.

[0034] Preferably, the graphene oxide-loaded photothermal fabric is prepared by weaving plain weave, twill weave, satin weave, double-layer weave, or plain weave fabric.

[0035] This invention also provides the application of the graphene oxide-loaded photothermal fabric in seawater desalination or personal thermal management. The photothermal composite yarn raw material is used to prepare woven or knitted fabrics, and specific effects are achieved through fabric structure design. The hydrophilic portion promotes rapid sweat diffusion, while the photothermal portion utilizes heat generated by outdoor sunlight to keep the body warm. The breathable design allows steam and sweat to be quickly expelled after evaporation, reducing local humidity and air saturation, thereby ensuring evaporation efficiency and wearing comfort.

[0036] The technical solution of the present invention has the following advantages compared with the prior art:

[0037] Rovings are pretreated by immersing them in carbon material dispersions of varying concentrations. After drying, carbon material particles are uniformly distributed on the surface of the roving. The dried roving is then drafted and twisted to produce a uniformly thick photothermal yarn. Subsequently, the photothermal yarn is sequentially set using a carbon material slurry. Photothermal and hydrophilic yarns are mixed in different proportions and processed sequentially through drafting and twisting. During the drafting stage, repeated stretching and thinning cause the yarn to continuously move radially, resulting in a finer yarn. During the twisting stage, applying an appropriate twist to the thinned yarn gives it a certain strength. During spinning, the carbon material particles initially attached to the yarn surface penetrate into the yarn's interior under the influence of tension and changes in yarn structure, ultimately producing a composite photothermal yarn. The photothermal properties of the composite photothermal yarn can be adjusted by modifying the concentration of the carbon material dispersion and the mixing ratio during stretching.

[0038] Traditional photothermal fabrics use different component yarns as warp and weft, adjusting performance by modifying the fabric structure. Evaporation efficiency needs to be optimized by adjusting the distribution of the photothermal conversion yarn and the water supply yarn. However, the heat generated by the yarn and the water supplied can only interact at the interlacing points of the warp and weft. In contrast, the heat generated by the composite photothermal yarn and the water supplied by the hydrophilic Tencel can come into contact across the entire yarn cross-section, significantly improving energy efficiency. Direct impregnation / drop coating is a relatively simple preparation method, but excess photothermal conversion material can clog the pores between the yarns, sacrificing the fabric's breathability and moisture permeability, thus reducing vapor dissipation and wearing comfort. Furthermore, coating methods can only load carbon materials onto the yarn surface, while this preparation method allows the carbon material to be uniformly and deeply embedded in the composite photothermal fabric, further improving energy conversion efficiency. Attached Figure Description

[0039] Figure 1 Flowchart for the preparation of graphene oxide-supported photothermal fabric.

[0040] Figure 2 Evaporation rate graphs for COC 0.1%, COC 0.5%, and COC 1.0%.

[0041] Figure 3 The evaporation rate diagram is for COC1, COC2, COC3, and COC4.

[0042] Figure 4 Evaporation rate graphs for GOT 0.1%, GOT 0.5%, and GOT 1.0%.

[0043] Figure 5 The evaporation rate diagrams for GOT1, GOT2, GOT3, and GOT4 are shown.

[0044] Figure 6 The graph shows the evaporation rate and evaporation efficiency of GOT3 in a 3.5 wt% sodium chloride solution over 15 cycles.

[0045] Figure 7 The graph shows the concentration changes and salt rejection rates of four main ions in real water samples (taken from the Yellow Sea) before and after GOT3 desalination.

[0046] Figure 8 The graph shows the moisture permeability and air permeability of different fabrics.

[0047] Figure 9 A graph showing the rate of increase in water quality measured under different sweating rates and solar intensities. Detailed Implementation

[0048] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0049] Example 1

[0050] A dispersion and slurry were obtained using carbon nanotube (CNT) powder as a solute. 600 tex cotton roving was ultrasonically treated in the CNT dispersion for 20 min at concentrations of 0.1 wt%, 0.5 wt%, and 1.0 wt%. After ultrasonication, it was dried in an oven at 40°C for 60 min. The dried roving was then stretched and twisted using ring spinning technology, achieving a stretch ratio of 38.2 and a twist coefficient of 360, yielding 19.7 tex CNT cotton yarn. The obtained CNT cotton yarn was then sequentially set using CNT slurry at a processing speed of 20 m / min and a drying temperature of 60°C, resulting in a solidified shell of CNTs on the yarn surface. The CNT yarn was then doubly twisted with hydrophilic cotton yarn at a 3:1 ratio to obtain a composite photothermal yarn. Finally, the composite photothermal yarn was woven into a plain weave photothermal fabric. When the concentration of CNT dispersion was 0.1wt%, 0.5wt%, and 1.0wt%, the mixing ratio of composite photothermal yarn to cotton yarn was set to 3:1, and the prepared fabrics were named COC0.1%, COC0.5%, and COC1.0%.

[0051] The evaporation rates of the photothermal fabrics prepared in this embodiment with COC 0.1%, COC 0.5%, and COC 1.0% were 1.02, 1.20, and 1.3 kg·m³, respectively. -2 ·h -1 .

[0052] Example 2

[0053] A dispersion and a slurry were obtained using carbon nanotube (CNT) powder as the solute. 600 tex cotton roving was ultrasonically treated in the CNT dispersion for 20 min. The CNT dispersion concentration was 1.0 wt%. After ultrasonication, the roving was dried in an oven at 40℃ for 60 min. The dried roving was then stretched and twisted using ring spinning technology, achieving a stretch ratio of 38.2 and a twist coefficient of 360, resulting in 19.7 tex CNT cotton yarn. The obtained CNT cotton yarn was then sequentially set using CNT slurry at a processing speed of 20 m / min and a drying temperature of 60℃, forming a solidified shell of CNTs on the yarn surface. The CNT cotton yarn was then doubly twisted with cotton yarn in ratios of 1:3, 2:2, 3:1, and 4:0 to obtain composite photothermal yarn. Finally, the composite photothermal yarn was woven into a plain weave photothermal fabric. When the mixing ratio of composite photothermal yarn to Tencel yarn is 1:3, 2:2, 3:1 and 4:0, and the concentration of CNT dispersion is set to 1.0 wt%, the prepared fabrics are named COC1, COC2, COC3 and COC4.

[0054] The evaporation rates of the photothermal fabrics COC1, COC2, COC3, and COC4 prepared in this embodiment were 1.10, 1.19, 1.30, and 1.28 kg·m³, respectively. -2 ·h -1 .

[0055] Example 3

[0056] Using graphene oxide (GO) powder as a solute, a dispersion and a sizing were obtained. 600 tex Tencel roving was ultrasonically treated in the GO dispersion for 20 min, with GO dispersion concentrations of 0.1 wt%, 0.5 wt%, and 1.0 wt%. After ultrasonication, it was dried in an oven at 40°C for 60 min. The dried roving was then stretched and twisted using ring spinning technology, achieving a stretch ratio of 38.2 and a twist coefficient of 360, yielding a 19.7 tex GO Tencel yarn. The obtained GO Tencel yarn was then sequentially set using GO sizing at a processing speed of 20 m / min and a drying temperature of 60°C, forming a solidified shell layer of GO on the yarn surface. The GO yarn was then doubly twisted with hydrophilic Tencel at a 3:1 ratio to obtain a composite photothermal yarn. Finally, the composite photothermal yarn was woven into a plain weave photothermal fabric. When the concentration of GO dispersion was 0.1wt%, 0.5wt%, and 1.0wt%, the mixing ratio of composite photothermal yarn to cotton yarn was set to 3:1, and the prepared fabrics were named GOT0.1%, GOT0.5%, and GOT1.0%.

[0057] The evaporation rates of the photothermal fabrics prepared in this embodiment with GOT content of 0.1%, 0.5%, and 1.0% were 1.01, 1.26, and 1.32 kg·m³, respectively. -2 ·h -1 .

[0058] Example 4

[0059] Using GO powder as a solute, a dispersion and a sizing were obtained. A 600 tex Tencel roving was ultrasonically treated in the GO dispersion (1.0 wt%) for 20 min. After ultrasonication, it was dried in an oven at 40°C for 60 min. The dried roving was then drafted and twisted using ring spinning technology, achieving a stretch ratio of 38.2 and a twist coefficient of 360, resulting in a 19.7 tex GO Tencel yarn. The obtained GO Tencel yarn was then sequentially set using GO sizing at a speed of 20 m / min and a drying temperature of 60°C, forming a solidified shell layer of GO on the yarn surface. The GO Tencel yarn was then doubly twisted with Tencel in ratios of 1:3, 2:2, 3:1, and 4:0 to obtain a composite photothermal yarn. Finally, the composite photothermal yarn was woven into a plain weave photothermal fabric. When the mixing ratio of GO Tencel loaded yarn to Tencel yarn is 1:3, 2:2, 3:1 and 4:0, and the concentration of GO dispersion is set to 1.0 wt%, the fabrics prepared are named GOT1, GOT2, GOT3 and GOT4.

[0060] The evaporation rates of GOT1, GOT2, GOT3, and GOT4 in the photothermal fabric prepared in this embodiment were 1.17, 1.23, 1.32, and 1.30 kg·m³, respectively.-2 ·h -1 GOT3 has an evaporation efficiency of over 89%, which is four times that of pure water.

[0061] Example 5

[0062] 600 tex Tencel roving was ultrasonically treated in a 1.0 wt% GO dispersion for 20 min. After ultrasonication, it was dried in an oven at 40°C for 60 min. The dried roving was then drafted and twisted using ring spinning technology, with a stretch ratio of 38.2 and a twist coefficient of 360, to obtain a 19.7 tex GO Tencel yarn. The obtained GO yarn was then sequentially set with GO sizing agent at a speed of 20 m / min and a drying temperature of 60°C, forming a solidified shell layer of GO on the yarn surface. The GO yarn was then doubly twisted with Tencel at a ratio of 3:1 to obtain GOT (Genuine Oxide Tissue). Finally, the GOT was woven into a plain weave light-cured fabric.

[0063] The photothermal fabric GOT3 prepared in this embodiment exhibited long-term desalination performance in simulated seawater (3.5 wt% NaCl solution) tests. The evaporation rate of GOT3 in simulated seawater was 88% of that in pure water, indicating that GOT is almost unaffected by salt ions during desalination. No salt particle accumulation was observed after 6 hours of continuous desalination. The slight decrease in evaporation rate is attributed to the delayed liquid-to-vapor phase transition caused by ions in seawater. Furthermore, due to rapid water supply and its porous structure, salt ions diffuse from the evaporation surface into the bulk water before reaching saturation concentration, thus preventing salt crystallization and deposition on the GOT surface. GOT demonstrates extremely high durability, such as… Figure 6 As shown, after 15 cycles, the desalination evaporation rate remained at 1.17 kg·m³. -2 ·h -1 Left and right. For example... Figure 7 As shown, after desalination, Ca 2+ Mg 2+ Na + and K + The ion repulsion efficiency reaches over 99%, meeting the standard requirements set by the World Health Organization (WHO) at 200 mg / L. -1 .

[0064] Example 6

[0065] 600 tex Tencel roving was ultrasonically treated in a 1.0 wt% GO dispersion for 20 min. After ultrasonication, it was dried in an oven at 40°C for 60 min. The dried roving was then drafted and twisted using ring spinning technology, with a stretch ratio of 38.2 and a twist coefficient of 360, to obtain 19.7 tex GO Tencel yarn. The obtained GO yarn was then sequentially set with GO sizing agent at a speed of 20 m / min and a drying temperature of 60°C, forming a solidified shell layer of GO on the yarn surface. The GO yarn was then doubly twisted with Tencel at a ratio of 3:1 to obtain GOT (Genuine Oxide Tissue). Finally, the GOT was woven into a heat-retaining and warm fabric.

[0066] The heat-storing and heat-insulating fabric GOT3 prepared in this embodiment has a vapor permeability of 2242 g·m³. -1 ·D -1 It contains over 90% of the original Tencel. GOT3 has a breathability of 170mm. -2 ·s -1 It is approximately 95% of the original Tencel. Figure 8 To investigate the perspiration performance of GOT3 under different solar radiation conditions, a heater was set to 35°C and placed on insulating foam to simulate human skin. A water pump sealed in a thin acrylic sheet was connected to the artificial skin surface to simulate different perspiration rates (1.5, 2, and 3 μL·s). -1 ).like Figure 9 As shown, at different solar intensities (0.6 and 1 kW·m), -2 The perspiration rate was measured under conditions of darkness, outdoors, and standard sunlight intensity. GOT3 exhibited good moisture transfer and perspiration capabilities in darkness. Furthermore, the heat generated by GOT3 under solar lighting promotes perspiration, keeping the user comfortable even under heavy perspiration.

[0067] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a photothermal composite yarn, characterized in that, Includes the following steps: S1: Prepare carbon material dispersion and carbon material slurry respectively; The carbon material dispersion includes carbon material and a dispersion medium, and the carbon material slurry includes carbon material, a binder, and a solvent. S2: The roving is treated with a carbon material dispersion and then dried to obtain treated roving; the roving is Tencel, cotton or linen; S3: The treated roving is stretched and twisted to obtain a composite yarn; S4: The composite yarn is sized, dried, and wound to obtain a photothermal yarn; the sizing agent used is the carbon material sizing agent. S5: The hydrophilic yarn and the photothermal yarn are drawn and twisted to obtain the photothermal composite yarn; in step S5, the twist of the drawn and twisted yarn is 20-80 T / 10cm, and the ratio of the number of ends of the hydrophilic yarn to the number of ends of the photothermal yarn is 1-3:1-3.

2. The preparation method according to claim 1, characterized in that, The carbon material is graphene, graphene oxide, carbon nanotubes, or carbon black.

3. The preparation method according to claim 1, characterized in that, The dispersion medium and solvent are both water, dimethylformamide, or dimethyl sulfoxide.

4. The preparation method according to claim 1, characterized in that, In step S3, the twist during stretching and twisting is 60-120 T / 10cm.

5. The preparation method according to claim 1, characterized in that, In step S4, the sizing speed is 20-30 m / min.

6. A photothermal composite yarn prepared by the preparation method according to any one of claims 1-5.

7. A graphene oxide-supported photothermal fabric, characterized in that, It is prepared using the photothermal composite yarn described in claim 6.

8. The application of the graphene oxide-supported photothermal fabric of claim 7 in seawater desalination or personal thermal management.

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