Recycling of polyester textile waste

Abstract

The application discloses a kind of recycling of polyester textile waste, comprising: textile waste is contacted with natural deep eutectic solvent;Un-dissolved polyester fiber is separated by filtration and is washed and dried;After drying treatment, polyester fiber is contacted with organic solvent mixture;Under the protection of inert gas, the mixture after dissolution is subjected to multistage membrane filtration, and the filtered solution is concentrated;The solution after concentration is divided into two parts, one part is added at least one functional monomer and photoinitiator, to obtain functional spinning solution, the other part is as base spinning solution;Functional spinning solution and base spinning solution are simultaneously transported to electrostatic field with voltage of 10-30kV, to form electric field gradient between solution conveying area and fiber collection area, adjust electric field distribution to control the deposition of fiber in collection area, to form nanofiber membrane in collection area.The technical scheme of the application can convert waste polyester textiles into high value-added products.

Description

Technical Field

[0001] This invention relates to the field of polyester textile waste recycling technology, and more particularly to a method for recycling polyester textile waste. Background Technology

[0002] Polyester textile waste refers to waste materials generated during the production and use of textiles. This waste is primarily made of polyethylene terephthalate (PET) and is one of the main components of global textile waste. Due to the high strength, durability, and chemical resistance of polyester fibers, they are widely used in clothing, home textiles, and many other fields. However, polyester textiles are difficult to degrade naturally after disposal, resulting in large amounts of solid waste accumulation and environmental pollution. Therefore, how to effectively recycle and utilize polyester textile waste has become one of the important issues in the current environmental protection field.

[0003] Current methods for treating polyester textile waste primarily involve mechanical recycling. These methods typically break down the waste into recycled fibers through shearing and high-temperature heat treatment. However, this process often leads to a significant decrease in the mechanical properties of the fibers, causing them to deform and break under stress, failing to maintain their original strength and toughness. The resulting recycled materials are of poor quality and cannot be used in the production of high-value-added products. Summary of the Invention

[0004] The main objective of this invention is to solve the technical problem that existing mechanical recycling methods cannot convert waste polyester textiles into products with high added value.

[0005] The first aspect of this invention provides a method for recycling polyester textile waste, wherein the recycling of polyester textile waste includes:

[0006] Textile waste is contacted with a natural deep eutectic solvent containing hydrogen bond acceptors and at least two hydrogen bond donors, and stirred at a preset temperature for a predetermined time.

[0007] Undissolved polyester fibers are separated by filtration, and the separated polyester fibers are then washed and dried.

[0008] The dried polyester fibers are contacted with an organic solvent mixture, the organic solvent mixture comprising haloalkanes, fluorinated organic acids and lactone compounds;

[0009] Under inert gas protection, the dissolved mixture is subjected to multi-stage membrane filtration, and the filtered solution is then concentrated.

[0010] The concentrated solution was divided into two parts. One part was mixed with at least one functional monomer and a photoinitiator to obtain a functionalized spinning solution, and the other part was used as the basic spinning solution.

[0011] Functionalized spinning solution and basic spinning solution are simultaneously transported to an electrostatic field with a voltage of 10-30kV to form an electric field gradient between the solution transport region and the fiber collection region. The electric field distribution is adjusted to control the deposition of fibers in the collection region, thereby forming a nanofiber membrane in the collection region.

[0012] Optionally, the step of contacting textile waste with a natural deep eutectic solvent, the natural deep eutectic solvent containing hydrogen bond acceptors and at least two hydrogen bond donors, and stirring at a preset temperature for a predetermined time includes:

[0013] Textile waste is cut into small pieces of 1-5cm² and vacuum dried at 50℃ for 6 hours.

[0014] The preparation steps for a natural deep eutectic solvent include: selecting choline chloride as a hydrogen bond acceptor, selecting lactic acid and urea as hydrogen bond donors, mixing them in a molar ratio of 1:2:0.5, adding 1 wt% of cerium oxide nanocatalyst, and heating from room temperature to 80°C at a heating rate of 2°C / min under nitrogen protection, stirring for 2 hours to form a transparent liquid.

[0015] The dried textile waste pieces were mixed with the prepared natural deep eutectic solvent at a mass ratio of 1:10.

[0016] The mixture is placed in a temperature-controlled reactor and stirred at a preset temperature for a predetermined time.

[0017] Optionally, the stirring at a preset temperature for a predetermined time includes:

[0018] The temperature was increased from room temperature to 60°C at a rate of 2°C / min and maintained at a stirring speed of 600 rpm for 1 hour.

[0019] Continue heating at a rate of 1℃ / min to 80℃, and maintain at a stirring speed of 800rpm for 2 hours;

[0020] Finally, the temperature was reduced to 70°C at a cooling rate of 1°C / min and maintained at a stirring speed of 700 rpm for 1 hour.

[0021] Optionally, the filtration process separates undissolved polyester fibers, and the separated polyester fibers are then washed and dried, including:

[0022] The reaction mixture was subjected to solid-liquid separation using a three-stage series filter with pore sizes of 50 μm, 30 μm and 10 μm, respectively.

[0023] The separated polyester fibers were subjected to multi-stage gradient ultrasonic cleaning, specifically including: first, cleaning with deionized water at a frequency of 40 kHz for 20 minutes, then cleaning with ethanol at a frequency of 60 kHz for 15 minutes, and finally cleaning with acetone at a frequency of 80 kHz for 10 minutes. The cleaning solution was removed by centrifugation between each cleaning stage.

[0024] The cleaned polyester fibers were pre-cooled at -40℃ for 2 hours.

[0025] Freeze-drying was carried out under a vacuum of 0.01 mbar. The temperature was first increased from -40°C to 0°C at a rate of 1°C / min and held for 6 hours, and then increased to room temperature at a rate of 0.5°C / min and held for 18 hours.

[0026] Pulse vacuum drying was performed at 40°C for 2 hours, with a pulse cycle of 2 minutes to evacuate to 0.1 mbar and 1 minute to introduce dry nitrogen to bring the pressure to atmospheric pressure.

[0027] Optionally, the step of contacting the dried polyester fibers with an organic solvent mixture, the organic solvent mixture comprising haloalkanes, fluorinated organic acids, and lactone compounds, including:

[0028] The preparation of an organic solvent mixture includes: selecting dichloromethane as a haloalkane, trifluoroacetic acid as a fluorinated organic acid, and γ-butyrolactone as a lactone compound, and mixing them in a volume ratio of 3:6:1.

[0029] The dried polyester fibers were mixed with the prepared organic solvent mixture at a mass ratio of 1:20.

[0030] Under nitrogen protection, the solution was first dissolved at 60°C for 2 hours, and then dissolved at 80°C for another 4 hours.

[0031] During the dissolution process, the reaction mixture was subjected to intermittent ultrasonic treatment for 1 minute every 30 minutes, with an ultrasonic power of 200W and a frequency of 40kHz.

[0032] Optionally, the step of performing multi-stage membrane filtration on the dissolved mixture under inert gas protection and concentrating the filtered solution includes:

[0033] Under inert gas protection, the dissolved mixture was filtered sequentially through filter membranes with pore sizes of 10 μm, 1 μm, and 0.1 μm.

[0034] During the filtration process, vibrations of 100-500 kHz are applied to the filter membrane;

[0035] The filtered solution is concentrated at a pressure of 0.1-1 mbar within a temperature range of -5℃ to 5℃, while the volatile solvent is condensed and recovered.

[0036] Optionally, the concentrated solution is divided into two parts, one part of which is mixed with at least one functional monomer and a photoinitiator to obtain a functionalized spinning solution, and the other part serves as the basic spinning solution, comprising:

[0037] The concentrated solution was divided into two equal parts;

[0038] A mixture of functional monomers, comprising hydrophobic monomers, hydrophilic monomers, and antibacterial monomers, is added to a portion of the solution at a mass fraction of 1-5%.

[0039] Add 0.1-1% of photosensitizing nanoparticles as photoinitiators to a solution containing functional monomers;

[0040] The solution containing the functional monomer and photoinitiator was stirred at 300-500 rpm for 30-60 minutes under light-protected conditions to obtain the functionalized spinning solution.

[0041] The other portion of the solution without added functional monomers was concentrated under reduced pressure at 60-80℃ for 10-30 minutes to obtain the basic spinning solution.

[0042] Optionally, the step of simultaneously delivering the functionalized spinning solution and the basic spinning solution to an electrostatic field with a voltage of 10-30kV, forming an electric field gradient between the solution delivery region and the fiber collection region, adjusting the electric field distribution to control fiber deposition in the collection region, and forming a nanofiber membrane in the collection region includes:

[0043] The functionalized spinning solution and the basic spinning solution are delivered separately through coaxial nozzles, with the functionalized spinning solution delivered through the inner nozzle and the basic spinning solution delivered through the outer nozzle.

[0044] A multi-electrode electric field is set between the nozzle and the collector, and a non-uniform electric field distribution is generated in the range of 10-30kV by adjusting the voltage of each electrode.

[0045] A conductive pattern is formed on the surface of the collector, the conductivity of the conductive pattern being at... arrive Adjustable within the S / m range;

[0046] During fiber deposition, a low-frequency vibration of 50-200 Hz is applied to the collector;

[0047] During the formation of the nanofiber membrane, the electric field strength and distribution are gradually changed through program control. The electric field strength changes by 1-3 kV every 5 minutes.

[0048] Optionally, after forming the nanofiber membrane in the collection region, the process includes:

[0049] The nanofiber membrane was placed in an environment filled with inert gas and irradiated with ultraviolet light at a wavelength of 280-320 nm for 10-30 minutes.

[0050] The cross-linked nanofiber membrane was heat-treated at 50-70℃ for 2-4 hours.

[0051] The heat-treated nanofiber membrane is immersed in a nano titanium dioxide solution with a mass fraction of 0.5-2% for 1-3 hours, and then dried at 80-100℃ for 30-60 minutes.

[0052] The core technical challenge is how to efficiently transform complex waste polyester textiles into high-value-added functional nanofiber materials while ensuring the environmental friendliness and economic feasibility of the entire process.

[0053] The technical solution provided in this application involves contacting textile waste with a natural deep eutectic solvent, enabling the separation of polyester fibers under mild conditions without damage. Natural deep eutectic solvents (NADES) are environmentally friendly solvents composed of hydrogen bond donors and acceptors, exhibiting high selectivity and good solubility, and achieving effective separation of fiber materials at relatively low temperatures. Unlike the fiber degradation problems that may occur during mechanical recycling, this invention uses a chemical separation step to extract polyester fibers at lower temperatures and in a milder environment, effectively preserving the physical and chemical properties of the polyester fibers. This method not only reduces mechanical damage to the fibers but also avoids the use of harmful chemicals through selective solvent design, improving the environmental friendliness and economic feasibility of the process.

[0054] This application further enhances the added value of polyester textile waste recycling through multi-stage membrane filtration and electrospinning technology. In the filtration stage, the multi-stage membrane processing effectively separates the dissolved polyester fibers, ensuring thorough removal of impurities and significantly improving the purity and quality of the final recycled fibers. The subsequent electrospinning process allows the recycled polyester fibers to be deposited into nanofiber membranes under the influence of an electric field, significantly improving the material's functionality. These nanofiber membranes not only possess excellent mechanical properties but can also be endowed with multiple functions such as hydrophobicity and antibacterial properties through the introduction of functional monomers, thus greatly expanding the application fields of recycled materials. Compared to traditional mechanical recycling methods, the technical solution of this invention not only improves the material recycling efficiency but also solves the defects of poor quality and limited uses of recycled materials in existing technologies through the preparation process of multifunctional materials. It truly realizes the transformation of polyester textile waste into high-value-added products, providing a practical solution for the sustainable recycling of waste textiles. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0056] Figure 1 This is a schematic diagram of an embodiment of the recycling of polyester textile waste according to the present invention.

[0057] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0059] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0060] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, provided that they are feasible for those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0061] One embodiment of this application provides a method for recycling polyester textile waste. Figure 1 This is a flowchart illustrating the recycling of polyester textile waste according to an embodiment of this application. In this embodiment, the method includes:

[0062] Please see Figure 1 Textile waste is contacted with a natural deep eutectic solvent containing hydrogen bond acceptors and at least two hydrogen bond donors, and stirred at a preset temperature for a predetermined time.

[0063] In one embodiment of the present invention, the step of contacting textile waste with a natural deep eutectic solvent, wherein the natural deep eutectic solvent contains hydrogen bond acceptors and at least two hydrogen bond donors, and stirring at a preset temperature for a predetermined time, includes: cutting the textile waste into small pieces of 1-5 cm² and vacuum drying at 50°C for 6 hours; preparing the natural deep eutectic solvent, the preparation steps of which include: selecting choline chloride as a hydrogen bond acceptor, selecting lactic acid and urea as hydrogen bond donors, mixing them at a molar ratio of 1:2:0.5, adding 1 wt% of cerium oxide nanocatalyst, and heating from room temperature to 80°C at a heating rate of 2°C / min under nitrogen protection, stirring for 2 hours to form a transparent liquid; mixing the dried textile waste pieces with the prepared natural deep eutectic solvent at a mass ratio of 1:10; and placing the mixture in a temperature-controlled reaction vessel and stirring at a preset temperature for a predetermined time.

[0064] Specifically, in this solution, textile waste is first cut into small pieces of 1-5 cm². This is to increase the surface area of ​​the textile waste in contact with the solvent, thereby enhancing the dissolution efficiency in subsequent processing. This step does not lead to a significant decrease in the mechanical properties of the fibers or fiber deformation and breakage due to stress, as is common in traditional mechanical recycling. Traditional mechanical recycling methods typically break polyester fibers into smaller particles or fibrous structures through high-intensity shearing, extrusion, or grinding. During this process, the fibers are subjected to intense physical forces, which damages the molecular chain structure of the fibers, causing a significant decrease in their mechanical properties (such as strength and toughness). The resulting recycled fiber materials are of poor quality and cannot meet the demands of high-value-added products. Moreover, the high-temperature heat treatment in mechanical recycling may further exacerbate this deterioration in mechanical properties, because at high temperatures, the molecular structure of polyester fibers undergoes irreversible changes, reducing their physical properties. In contrast, the operation of cutting textile waste into small pieces of 1-5 cm² in this solution is solely to increase the surface area of ​​the textile waste, thereby improving the efficiency of solvent-fiber contact. The force applied in this cutting process is relatively gentle, serving more as a pretreatment step than a destructive disruption of the fiber structure. Therefore, such cutting does not cause significant damage to the molecular structure of the polyester fibers, nor does it reduce their mechanical properties. Furthermore, the cut fiber pieces retain their intact morphology, without experiencing molecular chain breakage due to shear force, a significant difference from the "forceful crushing" in mechanical recycling. Because there is no high-intensity mechanical force, the fibers can maintain their original strength and toughness during subsequent dissolution, ensuring the high quality of the recycled materials.

[0065] Next, the cut textile waste is vacuum dried at 50°C for 6 hours. The purpose of the drying process is mainly to remove moisture or volatile impurities from the waste, ensuring that the subsequent dissolution process is not affected by moisture. The use of a vacuum environment avoids the risk of fiber oxidation or degradation in high-temperature air, and the temperature of 50°C is relatively low, far below the melting point of polyester fibers (usually around 260°C), so it will not cause damage to the fiber structure.

[0066] The dried textile waste pieces are mixed with a prepared natural deep eutectic solvent (NADES) at a mass ratio of 1:10. NADES is a green solvent composed of hydrogen bond acceptors and hydrogen bond donors. In this formulation, choline chloride is selected as the hydrogen bond acceptor, and lactic acid and urea are selected as hydrogen bond donors, mixed in a molar ratio of 1:2:0.5. Choline chloride and lactic acid can form a stable hydrogen bond network, enhancing the solvent's ability to dissolve polyester fibers. At the same time, urea further enhances the polarity of the solvent by forming additional hydrogen bonds, making the dissolution process more efficient. Compared with traditional mechanical methods, chemical dissolution can act more gently on the fiber structure, avoiding damage caused by mechanical force, thereby maintaining the integrity of the fiber's molecular chains.

[0067] Adding 1 wt% cerium oxide nanocatalyst to the solvent accelerates the dissolution reaction and reduces the energy required for the reaction. The entire solvent preparation process must be carried out under nitrogen protection to prevent oxidation of the solvent system by oxygen. After thorough stirring, the resulting transparent liquid will have good solubility and can act efficiently on polyester fibers.

[0068] After drying, small pieces of textile waste are mixed with a prepared natural eutectic solvent at a mass ratio of 1:10, the entire mixture is placed in a temperature-controlled reactor and stirred at a preset temperature. This temperature and stirring control ensures sufficient contact between the fibers and the solvent, allowing the polyester fibers to dissolve uniformly. Due to the mildness of the natural eutectic solvent and the controllability of the entire process, the molecular structure of the fibers is not damaged, thus preserving their mechanical properties. Ultimately, the dissolution of polyester fibers in the solvent not only avoids the damage problems associated with mechanical methods but also achieves efficient dissolution at lower temperatures and with less energy consumption, resulting in high-value-added recycled fiber materials.

[0069] In one embodiment of the present invention, the stirring at a preset temperature for a predetermined time includes: raising the temperature from room temperature to 60°C at a heating rate of 2°C / min and maintaining it at a stirring speed of 600 rpm for 1 hour; continuing to raise the temperature to 80°C at a heating rate of 1°C / min and maintaining it at a stirring speed of 800 rpm for 2 hours; and finally lowering the temperature to 70°C at a cooling rate of 1°C / min and maintaining it at a stirring speed of 700 rpm for 1 hour.

[0070] Specifically, the temperature was increased from room temperature to 60°C at a rate of 2°C / min. This slow heating not only prevented thermal damage to the polyester fibers but also gradually increased the interaction between the solvent and the fibers, promoting uniform dissolution of the fibers. 60°C was chosen as the intermediate temperature point because at this temperature, the solvent's fluidity and the polyester fiber's solubility reach a balance, which is beneficial for the further progress of the subsequent reaction. Furthermore, excessively rapid heating may cause rapid expansion or even deformation of the fibers, while excessively slow heating may lead to a decrease in dissolution efficiency; therefore, a heating rate of 2°C / min was adopted.

[0071] After reaching 60°C, the system was maintained at a stirring speed of 600 rpm for 1 hour. The purpose of stirring during this stage is to ensure thorough mixing of the fiber and solvent, while preventing fiber precipitation or adhesion to the reactor wall.

[0072] Next, the system continued to heat to 80°C at a rate of 1°C / min. Compared to the previous heating rate of 2°C / min, the heating rate in this stage was slowed down to further and smoothly enhance the solvent's solubility without causing thermal stress concentration in the fibers. The reaction temperature of 80°C is one of the key temperatures for polyester fiber dissolution; at this point, the solvent's solubility is optimal, and the polyester fiber molecular chains are fully expanded in the solvent. A stirring speed of 800 rpm provides stronger shear force to accelerate fiber dissolution while ensuring uniform fiber distribution in the solution and preventing localized solution stagnation.

[0073] After maintaining this temperature for 2 hours, the temperature was lowered from 80°C to 70°C at a rate of 1°C / min. A stable rate of temperature change was maintained during cooling to prevent rapid cooling of the solution, which could lead to recrystallization or precipitation of the solute. Slow cooling ensured that the molecular structure in the solution gradually stabilized, preventing the reorganization of fibers or solutes due to sudden temperature changes. Simultaneously, a stirring speed of 700 rpm ensured the homogeneity of the reaction system during cooling and prevented fiber aggregation or precipitation in the solvent.

[0074] Please continue reading. Figure 1 Undissolved polyester fibers are filtered out, and the separated polyester fibers are then washed and dried.

[0075] In one embodiment of the present invention, the filtration to separate undissolved polyester fibers, followed by cleaning and drying of the separated polyester fibers, includes: using a three-stage series filter to perform solid-liquid separation of the reaction mixture, wherein the pore sizes of the three-stage series filter are 50 μm, 30 μm, and 10 μm respectively; and performing multi-stage gradient ultrasonic cleaning on the separated polyester fibers, specifically including: first cleaning with deionized water at a frequency of 40 kHz for 20 minutes, then cleaning with ethanol at a frequency of 60 kHz for 15 minutes, and finally cleaning with ethanol at a frequency of 80 kHz. The polyester fibers were cleaned with acetone for 10 minutes at a certain frequency, and the cleaning solution was removed by centrifugation between each cleaning stage. The cleaned polyester fibers were pre-cooled at -40°C for 2 hours. The fibers were then freeze-dried under a vacuum of 0.01 mbar. The temperature was first increased from -40°C to 0°C at a rate of 1°C / min and held for 6 hours, and then increased to room temperature at a rate of 0.5°C / min and held for 18 hours. The fibers were then pulsed under vacuum at 40°C for 2 hours. The pulse cycle was 2 minutes to evacuate to 0.1 mbar and 1 minute to introduce dry nitrogen to atmospheric pressure.

[0076] Specifically, a three-stage cascade filter is a device that connects multiple filters with different pore sizes. These filters are arranged at intervals along the liquid flow direction, with pore sizes of 50 μm, 30 μm, and 10 μm respectively. This staged filtration method effectively traps particles of different sizes by progressively reducing the pore size. For example, the initial 50 μm filter removes larger impurities or undissolved solids, the next 30 μm filter further filters smaller particles, and the final 10 μm filter ensures the trapping of the finest solids. This design avoids the clogging risk of a single filter and ensures that fibers and impurities can be separated step by step, greatly improving filtration efficiency and stability.

[0077] After solid-liquid separation, the separated polyester fibers undergo multi-stage gradient ultrasonic cleaning. Ultrasonic cleaning utilizes high-frequency sound waves to form microbubbles in the liquid. The impact force generated when these bubbles rapidly burst effectively removes dirt and residual chemicals from the fiber surface. First, the fibers are cleaned with deionized water at 40kHz for 20 minutes. This step aims to remove initial dirt and water-soluble substances from the fiber surface. Deionized water does not contaminate the fibers, ensuring thorough cleaning. Next, the fibers are cleaned with ultrasound at 60kHz and an ethanol solution for 15 minutes. Ethanol, as an organic solvent, removes residual organic matter from the fiber surface, and its rapid evaporation facilitates the subsequent drying process. Finally, the fibers are cleaned with ultrasound at 80kHz and acetone for 10 minutes. Acetone, a powerful organic solvent, further removes those more difficult-to-dissolve organic residues. These three cleaning steps are performed sequentially to ensure thorough removal of all types of dirt and chemical residues from the fiber surface. After each ultrasonic cleaning, the cleaning solution is removed by centrifugation. High-speed rotation separates the fibers and cleaning solution, ensuring that the cleaned fibers are completely free of liquid residue.

[0078] After cleaning, the polyester fibers are pre-cooled at -40°C for 2 hours. This step prepares the fibers for subsequent freeze-drying. Pre-cooling allows the moisture in the fibers to freeze rapidly, forming ice crystals. This ensures that the moisture sublimates directly during freeze-drying, preventing liquid moisture from affecting the fiber structure. Next, the fibers enter the freeze-drying equipment, where a vacuum of 0.01 mbar is maintained. Freeze-drying is a process that directly sublimates solid water (ice) into gas under low-temperature vacuum, avoiding damage to the material from liquid moisture. The freeze-drying process first raises the temperature from -40°C to 0°C at a rate of 1°C / min and holds for 6 hours. This slow heating rate ensures uniform and stable sublimation of the ice crystals, preventing fiber shrinkage or deformation caused by excessively rapid heating. Subsequently, the temperature is raised to room temperature at a rate of 0.5°C / min and held for 18 hours to ensure complete sublimation of any remaining moisture, ensuring the fibers reach their optimal state after drying.

[0079] Finally, to further ensure the thorough drying of the polyester fibers, pulsed vacuum drying was performed at 40°C for 2 hours. Pulsed vacuum drying removes moisture by periodically changing the vacuum level. Specifically, the vacuum level was reduced to 0.1 mbar every 2 minutes, followed by the introduction of dry nitrogen gas to atmospheric pressure for 1 minute. In this way, trace amounts of moisture on the fiber surface can be gradually removed, while avoiding the stress that continuous vacuum might cause to the fiber surface. The pulsed operation ensures a gentle drying process, preventing the fibers from cracking or deforming due to over-drying, while the introduction of dry nitrogen gas accelerates the removal of volatile residues.

[0080] Please continue reading. Figure 1 The dried polyester fibers are contacted with an organic solvent mixture, the organic solvent mixture comprising haloalkanes, fluorinated organic acids and lactone compounds;

[0081] In one embodiment of the present invention, the step of contacting the dried polyester fiber with an organic solvent mixture, the organic solvent mixture comprising haloalkanes, fluorinated organic acids, and lactone compounds, includes: preparing the organic solvent mixture by: selecting dichloromethane as a haloalkanes, trifluoroacetic acid as a fluorinated organic acid, and γ-butyrolactone as a lactone compound, and mixing them at a volume ratio of 3:6:1; mixing the dried polyester fiber with the prepared organic solvent mixture at a mass ratio of 1:20; dissolving the mixture at 60°C for 2 hours under nitrogen protection, and then continuing to dissolve it at 80°C for 4 hours; during the dissolution process, intermittently sonicating the reaction mixture for 1 minute every 30 minutes, the sonication power being 200W and the frequency being 40kHz.

[0082] Specifically, dichloromethane, as a nonpolar solvent, can effectively dissolve polyester molecules, especially exhibiting excellent solubility for polymeric materials. Furthermore, trifluoroacetic acid, as a fluorinated organic acid, can further enhance the polarity of the solvent, helping to break the hydrogen bonds in the polyester fibers and thus promoting dissolution. γ-Butyrolactone, a compound commonly used to enhance solvent stability and reaction efficiency, serves as an auxiliary component, ensuring not only solution homogeneity but also helping to maintain the dissolution rate and uniformity of the fibers.

[0083] Mixing the dried polyester fibers with the solvent at a mass ratio of 1:20 ensures that the solvent fully covers the fiber surface and undergoes a uniform dissolution reaction. If the solvent ratio is too small, the contact area between the fiber and the solvent is insufficient, and the fiber cannot be completely dissolved; conversely, if the solvent ratio is too large, it will result in resource waste. The 1:20 ratio effectively dissolves the fiber while ensuring the rational use of resources.

[0084] Dissolving under nitrogen protection is to prevent oxidation or moisture absorption that might occur when dichloromethane and trifluoroacetic acid are exposed to air, thus maintaining the purity and stability of the solvent system. The nitrogen environment not only prevents the solvent from reacting with moisture or oxygen in the air, but also ensures that the solvent does not evaporate too quickly during dissolution, thereby maintaining the continuity and efficiency of the reaction.

[0085] The dissolution process is divided into two stages. First, dissolution is carried out at 60°C for 2 hours. The temperature is set at 60°C based on the dissolution characteristics of polyester fibers. At this temperature, the solvent can quickly penetrate the fiber structure and begin to dissolve the surface layer. During this process, the polyester molecular chains gradually unwind without experiencing excessive thermal stress, thus preserving the material's basic physical properties. The purpose of this stage is to slowly and uniformly initiate the dissolution of the fibers.

[0086] Next, the temperature is raised to 80°C and maintained for 4 hours. 80°C is the optimal temperature for dissolving polyester fibers. At this temperature, the intermolecular forces between the solvent and the fiber are greatly enhanced, and the molecular chains inside the fiber gradually unfold and dissolve into the solution. This process is prolonged for 4 hours, which is sufficient to ensure complete dissolution of the fiber and prevent the formation of unreacted residues during the dissolution process.

[0087] Furthermore, intermittent ultrasonic treatment was introduced to further promote dissolution. Ultrasonic treatment was performed for 1 minute every 30 minutes at a power of 200W and a frequency of 40kHz. Ultrasonic treatment, through cavitation, generates localized high pressure and microbubble rupture, effectively breaking down the undissolved, insoluble components of the polyester fiber and accelerating fiber disintegration. The intermittent nature of the treatment was designed to provide a continuous driving force for dissolution without damaging the fiber.

[0088] Please continue reading. Figure 1 Under the protection of inert gas, the dissolved mixture is subjected to multi-stage membrane filtration, and the filtered solution is then concentrated.

[0089] In one embodiment of the present invention, the step of performing multi-stage membrane filtration on the dissolved mixture under inert gas protection and concentrating the filtered solution includes: filtering the dissolved mixture sequentially through filter membranes with pore sizes of 10 μm, 1 μm, and 0.1 μm under inert gas protection; applying vibration of 100-500 kHz to the filter membranes during the filtration process; concentrating the filtered solution at a pressure of 0.1-1 mbar within a temperature range of -5°C to 5°C, while simultaneously condensing and recovering the volatile solvent.

[0090] Specifically, the use of an inert gas (such as nitrogen) for protection is to prevent the active ingredients in the solution from reacting with oxygen or moisture in the air during filtration, thus maintaining the stability and purity of the solution. This step aims to ensure that insoluble impurities in the solution are gradually filtered out. A 10μm primary filter membrane removes larger particles and fiber debris, while subsequent 1μm and 0.1μm filter membranes remove even finer particles and impurities, ensuring that only uniformly distributed dissolved components remain in the solution.

[0091] Applying vibrations at 100-500 kHz during filtration helps prevent membrane clogging, ensuring consistent and efficient filtration. Vibration, through minute mechanical amplitude, acts on the membrane, reducing particle accumulation on the membrane surface and preventing micropore blockage, thereby increasing filtration speed and extending membrane lifespan. Setting the vibration frequency between 100-500 kHz ensures sufficient cleaning across membranes of different sizes while avoiding excessive stress on the membrane structure.

[0092] Next, the filtered solution is concentrated. The concentration process is carried out within a temperature range of -5°C to 5°C to prevent excessive evaporation of volatile components and maintain the stability of the reaction liquid. At low temperatures, the solvent evaporation rate decreases, allowing for better control of the concentration effect and reducing the potential decomposition or denaturation of the solute due to temperature increases. Furthermore, applying a low pressure of 0.1-1 mbar during the concentration process effectively increases the solvent evaporation rate while preventing overheating of the solution.

[0093] Meanwhile, to minimize solvent waste and environmental impact, the volatile solvent is condensed and recovered during the concentration process. After evaporation, the solvent can be effectively converted back into a liquid state through the condensation system for easy reuse. This not only improves solvent utilization efficiency and reduces operating costs, but also reduces the environmental pollution caused by solvent evaporation emissions.

[0094] Please continue reading. Figure 1 The concentrated solution is divided into two parts. One part is added with at least one functional monomer and a photoinitiator to obtain a functionalized spinning solution, and the other part is used as the basic spinning solution.

[0095] In one embodiment of the present invention, the step of dividing the concentrated solution into two parts, one part of which is supplemented with at least one functional monomer and a photoinitiator to obtain a functionalized spinning solution, and the other part serving as a basic spinning solution, includes: dividing the concentrated solution into two equal parts; adding a functional monomer mixture with a mass fraction of 1-5% to one part of the solution, wherein the functional monomer mixture includes hydrophobic monomers, hydrophilic monomers, and antibacterial monomers; adding 0.1-1% of photosensitive nanoparticles as a photoinitiator to the solution with added functional monomers; stirring the solution with added functional monomers and photoinitiator at a speed of 300-500 rpm for 30-60 minutes under light-protected conditions to obtain a functionalized spinning solution; and concentrating the other part of the solution without added functional monomers under reduced pressure at 60-80°C for 10-30 minutes to obtain a basic spinning solution.

[0096] Specifically, the functional monomer mixture comprises hydrophobic, hydrophilic, and antimicrobial monomers. This formulation is designed to endow the final fiber material with multifunctionality. Hydrophobic monomers provide excellent water resistance, making the fiber suitable for special environmental conditions or applications; hydrophilic monomers enhance the material's hygroscopicity and affinity for water; and the addition of antimicrobial monomers imparts antimicrobial properties, particularly beneficial in the medical, hygiene, and textile fields, extending the material's lifespan and improving its safety. Through a rational ratio of these three types of monomers, the final spinning solution can simultaneously possess multiple functions, meeting the needs of various fields.

[0097] After the functional monomers are added to the solution, 0.1-1% of photosensitive nanoparticles are added as a photoinitiator. Photoinitiators can initiate polymerization reactions under light irradiation, and their introduction can control the timing and rate of polymerization, especially in photocontrolled reactions, where this process can precisely adjust the morphology and structure of the material. The use of photosensitive nanoparticles not only improves reaction efficiency but also ensures that polymerization is completed under lower energy light conditions, thereby reducing energy consumption. Furthermore, the small size of the nanoparticles allows for uniform dispersion in the solution without affecting the viscosity of the solution or the smooth progress of the spinning process.

[0098] Next, the solution containing the added functional monomer and photoinitiator is placed under light-protected conditions and stirred at 300-500 rpm for 30-60 minutes. The main purpose of this step is to ensure thorough mixing of the functional monomer, photoinitiator, and base solution. Light protection is used to prevent the photoinitiator from prematurely initiating the polymerization reaction during stirring, ensuring the entire system is uniformly dispersed before polymerization begins. A stirring speed of 300-500 rpm provides sufficient shear force to ensure solution homogeneity while avoiding excessive stirring rates that could lead to nanoparticle agglomeration or solution foaming, affecting spinning stability. The chosen stirring time ensures all components are completely dissolved and form a stable functionalized spinning solution.

[0099] For the other portion of the solution without added functional monomers, it is concentrated under reduced pressure at 60-80°C for 10-30 minutes to obtain the basic spinning solution. The purpose of reduced pressure concentration is to further remove the solvent, thereby bringing the solution to a suitable viscosity for spinning. The temperature range of 60-80°C ensures that the solvent evaporates rapidly under low pressure without causing thermal degradation of the solute or changes in solution properties. By adjusting the temperature and pressure conditions, the viscosity of the solution can be precisely controlled, ensuring good flowability and film-forming properties during subsequent spinning. The reduced pressure concentration time is adjusted according to the initial concentration and target viscosity of the solution to ensure that concentration is completed within 10-30 minutes, giving the solution stable spinning properties.

[0100] Please continue reading. Figure 1 The functionalized spinning solution and the basic spinning solution are simultaneously transported to an electrostatic field with a voltage of 10-30kV, forming an electric field gradient between the solution transport region and the fiber collection region. The electric field distribution is adjusted to control the deposition of fibers in the collection region, forming a nanofiber membrane in the collection region.

[0101] In one embodiment of the present invention, the simultaneous delivery of the functionalized spinning solution and the basic spinning solution to an electrostatic field with a voltage of 10-30 kV, forming an electric field gradient between the solution delivery region and the fiber collection region, and adjusting the electric field distribution to control fiber deposition in the collection region, thereby forming a nanofiber membrane in the collection region, includes: delivering the functionalized spinning solution and the basic spinning solution separately through a coaxial nozzle, wherein the functionalized spinning solution is delivered through an inner nozzle and the basic spinning solution is delivered through an outer nozzle; setting a multi-electrode electric field between the nozzle and the collector, and generating a non-uniform electric field distribution by adjusting the voltage of each electrode within the range of 10-30 kV; and forming a conductive pattern on the surface of the collector, wherein the conductivity of the conductive pattern is within a certain range. arrive Adjustable within the S / m range; during fiber deposition, a low-frequency vibration of 50-200Hz is applied to the collector; during the formation of the nanofiber membrane, the electric field strength and distribution are gradually changed by program control, with the electric field strength increasing or decreasing by 1-3kV every 5 minutes.

[0102] Specifically, in this design, the functionalized spinning solution and the base spinning solution are first delivered separately through coaxial nozzles. The coaxial nozzle design allows the functionalized spinning solution to be delivered through the inner nozzle, while the base spinning solution is delivered through the outer nozzle. The key to this design is that the two solutions do not mix during the spraying process because the strong electric field during electrospinning causes the solution to be instantly stretched into fibers. This extremely rapid stretching speed ensures that the solution is stretched into independent fiber structures before diffusion or mixing occurs, ultimately forming fibers with a "core-shell" structure. The functionalized solution serves as the core of the fiber, while the base solution coats the outer layer, thus forming a multi-layered composite fiber. The inner functionalized solution imparts specific functionalities to the fiber, such as antibacterial, hydrophilic, or hydrophobic properties, while the outer layer provides strength and physical protection, ensuring the fiber's durability and performance in applications.

[0103] Electrospinning relies on an electric field to stretch a solution to form fibers. Here's an explanation of why an electric field can stretch a solution: When an electric field is applied between the nozzle and the collector, the sprayed solution becomes charged. The electrostatic force exerted by the electric field overcomes the surface tension of the solution, causing it to be rapidly stretched into fibers from the nozzle. The electric field breaks down the cohesive forces of solution molecules by providing a strong electrostatic force, forming a fine filament structure. The electric field strength directly affects the fiber stretching speed and diameter. Higher electric field strength provides greater stretching force, producing finer fibers, while lower electric fields are suitable for producing coarser fiber structures. Furthermore, the non-uniform electric field setup ensures that the fibers are subjected to uniform force during stretching, preventing fiber entanglement or uneven deposition, thus guaranteeing the quality and consistency of the fiber membrane.

[0104] In this process, conductive patterns are formed on the collector surface, and the conductivity of these patterns is adjustable. By adjusting the local conductivity, the electric field distribution on the collector surface is affected, thereby precisely controlling the deposition location and density of the fibers. Adjusting the conductivity allows the intensity of the electric field to be guided in different areas of the collector surface, resulting in denser fiber deposition in desired areas and sparser fiber deposition in other areas. Through this precise control, the thickness and morphology of the fiber membrane can be adjusted according to different application requirements.

[0105] During fiber deposition, a low-frequency vibration of 50-200 Hz is applied to the collector. This step is to further optimize fiber alignment and deposition. The low-frequency vibration eliminates fiber accumulation caused by electrostatic adsorption, promoting uniform fiber diffusion on the collector surface and forming a smooth and consistent deposition layer. The vibration frequency is designed not to damage the fiber structure, but rather to encourage orderly fiber alignment on the collector surface, resulting in a denser and more uniform fiber membrane.

[0106] During the nanofiber membrane formation process, the electric field strength is dynamically adjusted by 1-3 kV every 5 minutes through programmed control to adapt to the fiber stretching and deposition requirements at different stages. This dynamic adjustment is designed to accommodate the needs of different fiber formation stages. Initially, when the fibers are stretched from the nozzle, a higher electric field strength provides sufficient stretching force, allowing the solution to rapidly form fine fibers. During gradual fiber deposition, appropriately reducing the electric field strength ensures more uniform fiber deposition, preventing excessive stretching that could lead to breakage or uneven deposition. By programmatically controlling the gradual adjustment of the electric field strength, appropriate stretching force is ensured on the fibers during the forming and deposition stages, resulting in a uniform and dense fiber membrane, improving its mechanical properties and structural consistency.

[0107] In one embodiment of the present invention, after forming a nanofiber membrane in the collection area, the process includes: placing the nanofiber membrane in an environment filled with inert gas and irradiating it under ultraviolet light with a wavelength of 280-320 nm for 10-30 minutes; heat-treating the cross-linked nanofiber membrane at 50-70°C for 2-4 hours; immersing the heat-treated nanofiber membrane in a nano-titanium dioxide solution with a mass fraction of 0.5-2% for 1-3 hours, and then drying it at 80-100°C for 30-60 minutes.

[0108] Specifically, in this scheme, after the nanofiber membrane is formed, it needs to undergo further treatment to enhance its function and structural stability. First, the nanofiber membrane is placed in an environment filled with an inert gas (such as nitrogen or argon) and irradiated with ultraviolet light at a wavelength of 280-320 nm for 10-30 minutes. This step induces a photocrosslinking reaction through ultraviolet light irradiation, causing the molecular chains inside the fibers to form a more stable three-dimensional network structure, enhancing the mechanical strength and chemical resistance of the nanofiber membrane. An inert gas environment is chosen to avoid oxygen interfering with the crosslinking reaction and to prevent oxidation of the membrane surface, thus maintaining chemical stability. The irradiation time of 10-30 minutes ensures the crosslinking reaction proceeds fully without excessively damaging the membrane structure.

[0109] After UV irradiation, the fiber membrane is then heat-treated at 50-70°C for 2-4 hours. The purpose of heat treatment is to further stabilize the cross-linked structure, eliminate residual stress in the material, and improve the crystallinity and mechanical properties of the fiber membrane through molecular chain rearrangement. Choosing this temperature range avoids high-temperature damage to the membrane structure while effectively improving the material's strength and flexibility. Next, the heat-treated nanofiber membrane is immersed in a 0.5-2% (w / w) nano-titanium dioxide solution for 1-3 hours. Nano-titanium dioxide imparts additional functions to the fiber membrane, such as photocatalysis, antibacterial properties, and self-cleaning properties. Immersion in a solution at this concentration allows for the formation of a uniform titanium dioxide particle coating on the membrane surface, ensuring a uniform distribution of functionality. The immersion time is controlled at 1-3 hours to ensure sufficient particle adhesion without affecting the pore structure of the fiber membrane.

[0110] After impregnation, the fiber membrane is dried at 80-100℃ for 30-60 minutes to remove moisture from the solution and cure the titanium dioxide coating. The drying temperature of 80-100℃ accelerates moisture evaporation while avoiding damage to the fiber membrane structure from excessive heat. The 30-60 minute drying time ensures uniform curing of the coating and complete evaporation of moisture, allowing the titanium dioxide particles to firmly adhere to the membrane surface. Through these processing steps, the nanofiber membrane not only possesses excellent mechanical strength but also photocatalytic and antibacterial functions, ensuring outstanding performance in a variety of applications.

[0111] It should also be noted that the natural deep eutectic solvent (NADES) in this application can be recycled and reused. Due to its good stability and low volatility, NADES does not undergo chemical decomposition or significant loss during textile waste treatment. After treatment, the solvent can be separated from the reaction system by methods such as low-temperature evaporation or vacuum distillation, and then purified and concentrated to restore its original properties. In this way, the recovered NADES can be reused in new textile waste treatment cycles, ensuring the sustainability and economy of the process, and significantly reducing solvent waste and environmental impact.

[0112] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A recycling of polyester textile waste, characterized in that, The method comprises the following steps: contacting the textile waste with a natural deep eutectic solvent containing a hydrogen bond acceptor and at least two hydrogen bond donors, stirring at a preset temperature for a predetermined time; separating the undissolved polyester fibers by filtration, and washing and drying the separated polyester fibers; contacting the dried polyester fibers with an organic solvent mixture containing a halogenated alkane, a fluorine-containing organic acid, and a lactone compound; under the protection of an inert gas, performing multi-stage membrane filtration on the dissolved mixture, and concentrating the filtered solution; dividing the concentrated solution into two parts, adding at least one functional monomer and a photoinitiator to one part to obtain a functional spinning solution, and using the other part as a base spinning solution; specifically comprising: dividing the concentrated solution into two equal parts; adding a functional monomer mixture with a mass fraction of 1-5% to one part of the solution, the functional monomer mixture including a hydrophobic monomer, a hydrophilic monomer, and an antibacterial monomer; adding 0.1-1% of photosensitive nanoparticles as a photoinitiator to the solution containing the functional monomer; stirring the solution containing the functional monomer and the photoinitiator at a speed of 300-500 rpm for 30-60 minutes in the dark to obtain a functional spinning solution; and concentrating the other part of the solution without the functional monomer under reduced pressure at 60-80°C for 10-30 minutes to obtain a base spinning solution; The functionalized spinning solution and the basic spinning solution are simultaneously delivered to an electrostatic field with a voltage of 10-30 kV, an electric field gradient is formed between the solution delivery area and the fiber collection area, the electric field distribution is adjusted to control the deposition of the fibers in the collection area, and a nanofiber membrane is formed in the collection area; specifically comprising: delivering the functionalized spinning solution and the basic spinning solution through coaxial nozzles, wherein the functionalized spinning solution is delivered through the inner nozzle, and the basic spinning solution is delivered through the outer nozzle; a multi-pole electric field is arranged between the nozzle and the collector, and a non-uniform electric field distribution is generated by adjusting the voltage of each pole in the range of 10-30 kV; an electrically conductive pattern is arranged on the surface of the collector, and the conductivity of the electrically conductive pattern is adjustable in the range of 10-3 to S / m; during the fiber deposition process, a low-frequency vibration of 50-200 Hz is applied to the collector; during the formation of the nanofiber membrane, the electric field strength and distribution are gradually changed through program control, and the change range of the electric field strength is 1-3 kV per 5 minutes.

2. The recycling of polyester textile waste according to claim 1, characterized in that, the step of contacting the textile waste with a natural deep eutectic solvent containing a hydrogen bond acceptor and at least two hydrogen bond donors, stirring at a preset temperature for a predetermined time, comprises: cutting the textile waste into small pieces of 1-5 cm², and vacuum drying at 50°C for 6 hours; preparing a natural deep eutectic solvent, the preparation steps comprising: selecting choline chloride as the hydrogen bond acceptor, selecting lactic acid and urea as the hydrogen bond donors, mixing them in a molar ratio of 1:2:0.5, adding 1 wt% of cerium oxide nano-catalyst, and stirring at a temperature increasing rate of 2°C / min from room temperature to 80°C under nitrogen protection for 2 hours to form a transparent liquid; mixing the dried textile waste pieces with the prepared natural deep eutectic solvent in a mass ratio of 1:10; placing the mixture in a temperature-controllable reaction kettle and stirring at a preset temperature for a predetermined time.

3. The recycling of polyester textile waste according to claim 2, characterized in that, the step of stirring at a preset temperature for a predetermined time, comprises: increasing the temperature at a rate of 2°C / min from room temperature to 60°C, and maintaining the stirring speed at 600 rpm for 1 hour; continuing to increase the temperature at a rate of 1°C / min to 80°C, and maintaining the stirring speed at 800 rpm for 2 hours; finally, decreasing the temperature at a rate of 1°C / min to 70°C, and maintaining the stirring speed at 700 rpm for 1 hour.

4. The recycling of polyester textile waste according to claim 1, characterized in that, the step of separating the undissolved polyester fibers by filtration, and washing and drying the separated polyester fibers, comprises: using a three-stage series filter with pore sizes of 50 μm, 30 μm, and 10 μm in sequence to separate the solid and liquid in the reaction mixture; The separated polyester fibers are subjected to multi-stage gradient ultrasonic cleaning, specifically including: first cleaning with deionized water at a frequency of 40 kHz for 20 minutes, then cleaning with ethanol at a frequency of 60 kHz for 15 minutes, and finally cleaning with acetone at a frequency of 80 kHz for 10 minutes, and centrifugal separation is used to remove the cleaning liquid between each stage of cleaning; The cleaned polyester fibers are pre-cooled at -40°C for 2 hours; Freeze-drying is performed under a vacuum of 0.01 mbar, first raising the temperature from -40°C to 0°C at a rate of 1°C / min and maintaining for 6 hours, and then raising the temperature to room temperature at a rate of 0.5°C / min and maintaining for 18 hours; Pulse vacuum drying is performed at 40°C for 2 hours, with a pulse cycle of 2 minutes of vacuuming to 0.1 mbar, and 1 minute of dry nitrogen gas being introduced to normal pressure.

5. The recycling of polyester textile waste according to claim 1, characterized in that, The dried polyester fibers are contacted with an organic solvent mixture, and the organic solvent mixture comprises a halogenated alkane, a fluorine-containing organic acid, and a lactone compound, including: The organic solvent mixture is prepared, including: selecting dichloromethane as the halogenated alkane, trifluoroacetic acid as the fluorine-containing organic acid, and γ-butyrolactone as the lactone compound, and mixing at a volume ratio of 3:6:1; The dried polyester fibers are mixed with the prepared organic solvent mixture at a mass ratio of 1:20; Under nitrogen protection, first dissolving at 60°C for 2 hours, and then continuing to dissolve at 80°C for 4 hours; During the dissolving process, the reaction mixture is subjected to 1 minute of intermittent ultrasonic treatment every 30 minutes, with a power of 200 W and a frequency of 40 kHz.

6. The recycling of polyester textile waste according to claim 1, characterized in that, The dissolved mixture is subjected to multi-stage membrane filtration under inert gas protection, and the filtered solution is subjected to concentration treatment, including: The dissolved mixture is sequentially filtered through filter membranes with pore sizes of 10 μm, 1 μm, and 0.1 μm under inert gas protection; During the filtering process, a vibration of 100-500 kHz is applied to the filter membrane; The filtered solution is concentrated at a pressure of 0.1-1 mbar within a temperature range of -5°C to 5°C, while the volatilized solvent is condensed and recovered.

7. The recycling of polyester textile waste according to claim 1, characterized in that, After the nanofiber membrane is formed in the collection area, then including: The nanofiber membrane is placed in an inert gas-filled environment and irradiated under ultraviolet light at a wavelength of 280-320 nm for 10-30 minutes; The crosslinked nanofiber membrane is subjected to heat treatment at 50-70°C for 2-4 hours; The heat-treated nanofiber membrane is immersed in a nanometer titanium dioxide solution with a mass fraction of 0.5-2% for 1-3 hours, and then dried at 80-100°C for 30-60 minutes.

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