A method for selectively surface functionalizing hydrophilic fibers in a blended yarn

Abstract

The application belongs to the technical field of functional textile materials, and specifically discloses a method for selectively and selectively functionalizing the surface of hydrophilic fibers in blended yarns. The application utilizes the difference in surface energy between hydrophilic and hydrophobic fibers to selectively enrich the reactants in the aqueous reaction system on the surface of the hydrophilic fibers. By adjusting the pH of the system, dopamine self-polymerization and in-situ reduction of functional components are triggered, forming a composite functional coating on the surface of the hydrophilic fibers, while the hydrophobic fibers remain in their original state. The method is simple and environmentally friendly, and the resulting product has multiple special functions while retaining the original comprehensive performance of the blended yarns, making it suitable for various textile scenarios.

Description

Technical Field

[0001] This invention relates to the field of functional textile materials technology, and more specifically to a method for selectively surface functionalizing hydrophilic fibers in blended yarns. Background Technology

[0002] With the advancement of technology and the upgrading of consumer demand, modern textiles have transcended the traditional basic functions of warmth and cover, and are rapidly developing towards high performance, intelligence, and multi-functionality. Functional textiles, which are textile products endowed with one or more special functions such as antibacterial, antistatic, UV protection, waterproof and breathable properties, and far-infrared health benefits through specific technical means, have become the most dynamic and value-added research hotspot and market growth point in the textile industry.

[0003] To achieve the functionalization of textiles, the industry has developed various technological approaches, mainly including the development of functional fibers and the finishing of fabrics. Among them, functional fibers are prepared by adding functional masterbatches to the spinning solution, which has good functional durability, but suffers from high R&D costs and poor production flexibility. Fabric finishing technology, on the other hand, adds functional auxiliaries after the fabric is woven through padding, coating, and other methods. It has the advantages of flexible processes and relatively low costs, and is currently the mainstream method for achieving fabric functionalization.

[0004] In recent years, with the rise of nanotechnology, nanomaterials such as nano-silver, nano-oxides, and graphene, due to their unique size and surface effects, can endow textiles with superior performance and durability far exceeding that of traditional chemical auxiliaries. Their application in textile finishing has become a revolutionary means of improving fabric functionality. However, blended yarns / fabrics, due to their ability to combine the advantages of different fibers (such as the strength of polyester and the comfort of bamboo viscose), dominate the textile market. But existing technologies face significant challenges and bottlenecks when performing functional finishing on these blended products. First, existing finishing processes generally lack "selectivity." Whether it's the traditional padding method or the modern coating method, functional additives or nanomaterials are usually deposited indiscriminately on the surface of all fibers in blended fabrics. On the one hand, this may damage the overall performance and style of the fabric. For example, when waterproofing polyester / cotton blended fabrics, although it can give cotton fibers waterproofness, it may cover the original luster and crispness of polyester fibers, resulting in a poorer overall hand feel and loss of style. On the other hand, it results in low functional efficiency and high costs. In scenarios where only one type of fiber needs to be functionalized, indiscriminate treatment will lead to the waste of functional materials on fibers that do not need to be functionalized. Secondly, the adhesion of functional coatings has long been a challenge. Most finishing techniques rely on physical adsorption or low-energy chemical bonding, resulting in coatings that are prone to peeling off after repeated washing and rubbing. This leads to rapid degradation of functionality, poor wash resistance, and severely limits the durability and practical application value of functional textiles. To solve this problem, crosslinking agents or adhesives are usually used, but this introduces new chemicals and may make the fabric feel stiffer. Furthermore, the application processes for advanced materials such as graphene and nano-silver are still immature. Although these materials possess excellent electrical conductivity and antibacterial properties, existing methods for applying them to textile fibers (such as vacuum deposition and chemical bonding) are often complex and require expensive equipment, making them unsuitable for large-scale industrial production.

[0005] In summary, a method for selectively surface functionalizing hydrophilic fibers in blended yarns is now provided. Summary of the Invention

[0006] The purpose of this invention is to provide a method for selectively surface functionalizing hydrophilic fibers in blended yarns, so as to solve the problems of non-selectivity, complex process and poor adhesion in the existing technology for functionalizing blended yarns or fabrics.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A method for selectively surface functionalizing hydrophilic fibers in blended yarns includes the following steps: Step a: Immerse the blended yarn in an aqueous reaction solution containing dopamine compounds, graphene oxide materials, and soluble silver salts; Step b: Adjust the pH of the aqueous reaction solution to weakly alkaline. Utilizing the characteristic that the hydrophilic fiber is more easily wetted by the aqueous reaction solution than the hydrophobic fiber in the blended yarn, the dopamine compound preferentially undergoes self-polymerization on the surface of the hydrophilic fiber, and simultaneously reduces the graphene oxide material to reduced graphene material, and reduces the silver ions in the soluble silver salt to silver nanoparticles. Step c: Under the set reaction conditions, a composite coating comprising polydopamine polymers, reduced graphene-like materials, and silver nanoparticles is selectively formed on the surface of the hydrophilic fibers. In a further embodiment, in step b, the pH value of the aqueous reaction solution is adjusted to 7.5 to 9.5. In a further embodiment, in step c, the set reaction conditions are: a reaction temperature of room temperature (60℃~121℃) and a reaction time of 10min~4h; wherein, when the reaction temperature is room temperature~60℃, the reaction time is 1~4h; and when the reaction temperature is 121℃, the reaction time is 10~30min.

[0008] In a further embodiment, the dopamine compound includes one or more of dopamine hydrochloride, dopamine sulfate, and dopamine acetate; The graphene oxide materials include one or more of graphene oxide and modified graphene oxide. The soluble silver salt includes one or more of silver nitrate, silver acetate, silver sulfate, silver lactate, and silver citrate.

[0009] In a further embodiment, the hydrophobic fiber includes one or more of polyester fiber, nylon, polypropylene, acrylic fiber, and vinylon. The hydrophilic fiber is a cellulose-based fiber, which includes one or more of cotton fiber, hemp fiber, viscose fiber, lyocell fiber, modal fiber, cupro fiber, and bamboo pulp fiber.

[0010] In a further embodiment, in step a, the aqueous reaction solution further comprises a buffer, the buffer comprising one or more of tris(hydroxymethyl)aminomethane buffer, ammonia-ammonium chloride buffer, and borax-boric acid buffer.

[0011] In a further embodiment, step a is included before step a, which involves pre-treating the blended yarn, including washing, rinsing, and drying. The washing process uses an aqueous solution containing a surfactant, wherein the surfactant is a nonionic surfactant. In a further embodiment, step c is followed by hot rinsing, cold rinsing, and drying; the hot rinsing temperature is 70 to 90°C, and the rinsing time is 5 to 15 minutes. A functional blended yarn is provided, wherein the yarn is composed of at least one hydrophobic fiber and at least one hydrophilic fiber; the surface of the hydrophilic fiber is covered with a functional nanocomposite coating, wherein the functional nanocomposite coating is based on a polydopamine polymer, and the matrix contains reduced graphene-like materials and silver nanoparticles dispersed therein; the surface of the hydrophobic fiber remains essentially uncoated. In a further embodiment, the hydrophobic fiber includes one or more of polyester fiber, nylon, polypropylene, acrylic fiber, and vinylon; the hydrophilic fiber is a cellulose-based fiber, which includes one or more of cotton fiber, linen fiber, viscose fiber, lyocell fiber, modal fiber, cupro fiber, and bamboo pulp fiber. In a further embodiment, the functional blended yarn has one or more of the following properties: antibacterial properties, antistatic properties, UV resistance properties, and far-infrared health care properties. A functional textile, said textile being made from the above-mentioned functional blended yarn by woven, knitted or nonwoven processes; A functional textile, comprising one of the following: apparel fabrics, home textiles, medical and health textiles, smart textiles, and industrial textiles.

[0012] The core of this invention lies in the synergistic effect of two mechanisms: "differential wetting kinetics" and "dopamine-mediated in-situ self-assembly". The entire process is completed in a simple aqueous system. Through precise temporal and spatial control, the targeted functionalization of specific fibers in blended yarns is achieved. (1) Source of selectivity: differential wetting kinetics This is the physical basis for achieving "targeted" functionalization. When blended yarns are immersed in an aqueous reaction solution, hydrophilic fibers (such as bamboo viscose fiber) have a high surface energy due to their rich polar groups such as hydroxyl groups. The aqueous reaction solution is instantly and preferentially adsorbed and completely wetted by these fibers, and the reactants (dopamine compounds, graphene oxide materials, silver ions) immediately accumulate on and around the surface of the fiber. In contrast, hydrophobic fibers (such as polyester fiber) lack polar groups and have a low surface energy. In the initial stage of immersion in the solution, they repel the aqueous solution, forming a very thin "air jacket" or only discontinuous droplets adhering to the surface. This huge difference in wetting speed and degree due to the difference in surface energy pre-determines a "reaction zone" for subsequent chemical reactions at the microscopic scale. Within seconds to minutes, the reactants reach a local concentration on the surface of hydrophilic fibers that is much higher than that on the surface of hydrophobic fibers.

[0013] (2) Functionalized engine: Dopamine-mediated in situ self-assembly When the pH of the system is adjusted to a slightly alkaline state (pH>7.5) by adding a weak base, dopamine compounds are activated, simultaneously driving the following three key processes: ① Formation of a strong adhesive layer (“bio-adhesive”): Dopamine compounds rapidly undergo oxidative self-polymerization under aerobic and alkaline conditions to form polydopamine polymers with super-strong adhesive capabilities. This polymer can form a strong bond with almost all types of material surfaces (including cellulose) through covalent and non-covalent bonds (such as hydrogen bonds, π-π stacking), constituting the adhesive matrix of the entire functional coating; ② In-situ generation of functional nanoparticles: During the polymerization of dopamine compounds, the catechol groups in their molecular structure act as powerful reducing agents, simultaneously reducing the graphene oxide materials already enriched on the surface of hydrophilic fibers to conductive reduced graphene materials, and reducing silver ions in situ to silver nanoparticles with strong antibacterial properties. ③ Integrated co-deposition: The above processes occur simultaneously and intertwine with each other. The newly generated reduced graphene-like material sheets and silver nanoparticles are physically embedded and chemically fixed by the polymer network of polydopamine-like materials that are polymerizing at the same time. Finally, a dense, uniform, and firmly bonded ternary nanocomposite coating is formed on the surface of the hydrophilic fiber.

[0014] In summary, the mechanism of this invention can be summarized as a combination of physical selection and chemical construction: First, through "differential wetting kinetics", the aqueous reaction system physically "automatically identifies" and selects hydrophilic fibers as the target sites for the reaction, precisely delivering all "building materials" (reactants) to the desired location; then, by adjusting the pH value to activate the "dopamine engine", efficient "in-situ construction" is carried out at the preset target sites, completing the entire process of adhesive laying, functional material manufacturing, and firmly integrating the two into an integrated functional coating in one go.

[0015] The present invention has the following beneficial effects: Selective and precise, preserving original performance: By leveraging the difference in fiber surface energy, precise targeted functionalization is achieved. Functional coatings are constructed only on hydrophilic fibers without altering the inherent properties of hydrophobic fibers. This allows the product to acquire new functions while perfectly preserving the original style, feel, and overall performance of the blended yarn, solving the problem of style loss caused by indiscriminate processing in existing technologies.

[0016] With outstanding technological advantages and easy industrialization: it adopts the "one-pot" impregnation process, which is simple and efficient, and the reaction system is green and environmentally friendly. It does not require harsh reagents and complex equipment, significantly reducing production costs and production cycle, and has great potential for industrial promotion.

[0017] Excellent adhesion and strong durability: Using polydopamine as the adhesion matrix, functional components are generated in situ and simultaneously embedded to form an integrated coating, which is firmly bonded to the fiber, giving the product excellent wash and abrasion resistance, effectively solving the core pain point of poor durability of functional textiles.

[0018] Multifunctional integration and high added value: A single treatment can endow products with composite functions such as antibacterial and antistatic properties, while also providing additional health-related properties, greatly enhancing the product's functional diversity and market competitiveness. Attached Figure Description

[0019] Figure 1 The diagram shows the specific steps of the preparation method of the present invention. Detailed Implementation

[0020] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0021] Example 1 Experimental materials and equipment Material: Polyester / bamboo viscose (70 / 30 by weight) blended yarn, total weight approximately 50g; Chemical reagents: dopamine hydrochloride (98% purity), graphene oxide aqueous dispersion (4 mg / mL), silver nitrate (analytical grade), tris(hydroxymethyl)aminomethane (biobuffer grade), hydrochloric acid (37%), nonionic surfactant (Triton X-100), deionized water; Main equipment: laboratory constant temperature water bath shaker, magnetic stirrer, high-precision electronic balance (0.1mg), pH meter, small fabric sample dryer.

[0022] Preparation steps (1) Pretreatment of yarn (washing and impurity removal): Prepare an aqueous solution containing 0.5 g / L nonionic surfactant (Triton X-100), immerse the yarn sample in the solution, and wash it in a water bath at 40°C for 30 minutes to remove residual oil, sizing and other impurities on the yarn surface; take out the sample and rinse it repeatedly with a large amount of deionized water until the water becomes neutral and there is no foam; dry the cleaned yarn sample in an oven at 60°C to constant weight and set aside.

[0023] (2) Preparation of functionalized reaction solution: In a 1L clean beaker, add about 800mL of deionized water and 1.21g of tris(hydroxymethyl)aminomethane powder (concentration 10mM), and stir magnetically to dissolve it completely; use 1M hydrochloric acid solution to precisely adjust the pH of the solution to 8.5; in the above solution with continuous stirring, first add 2.0g of dopamine hydrochloride to dissolve it completely (the solution is colorless or pale yellow); under light-protected conditions (the beaker is wrapped with aluminum foil), slowly add 0.17g of silver nitrate and continue stirring until completely dissolved; finally, slowly add 50mL of graphene oxide aqueous dispersion (4mg / mL, i.e., add 200mg of graphene oxide), and continue stirring in the dark for 30 minutes to ensure that all components are uniformly dispersed, and obtain a dark brown homogeneous reaction mixture.

[0024] (3) Selective functionalization treatment: The pretreated dry yarn sample is completely immersed in the above-prepared reaction solution with a bath ratio of 1:20 to ensure that the yarn is fully and evenly wetted; the beaker containing the yarn and reaction solution is placed in a constant temperature water bath shaker at 40°C and shaken slowly at a rate of 50 rpm for 3 hours (within a few minutes after the start of the reaction, the solution color rapidly darkens to dark black, indicating that dopamine has begun to polymerize in large quantities).

[0025] (4) Reaction termination and post-treatment: After 3 hours of reaction, the yarn sample was taken out immediately; the sample was rinsed in hot water at 80°C for 10 minutes to remove the surface physically adsorbed, unbound polydopamine and nanoparticles; then it was rinsed repeatedly with a large amount of cold deionized water until the washing water became clear and colorless; the cleaned functional yarn sample was dried in an oven at 60°C to obtain functional blended yarn.

[0026] Performance testing was conducted on the functional blended yarn prepared above, and the results are as follows: Antibacterial properties: Antibacterial rate against Escherichia coli and Staphylococcus aureus ≥99%; Antistatic properties: Surface resistivity ≤10 8 Ω; Washability: After 50 standard household washes, the antibacterial rate remains ≥95%, and the antistatic performance shows no significant decline. Feel and style: It retains the original crispness and luster of polyester fiber, while maintaining the softness and comfort of bamboo viscose fiber.

[0027] Example 2 Experimental materials and equipment: Material: Polyester / cotton (60 / 40 by weight) blended knitted fabric, total weight approximately 50g; Chemical reagents: dopamine sulfate, modified graphene oxide aqueous dispersion (concentration 5 mg / mL), silver acetate, ammonia-ammonium chloride buffer, nonionic surfactant, deionized water; Main equipment: Same as in Example 1.

[0028] Preparation steps (1) Pretreatment: Same as step (1) in Example 1; (2) Preparation of reaction solution: Prepare ammonia-ammonium chloride buffer (pH=9.0), add 1.8g dopamine sulfate to the buffer, dissolve and add 0.2g silver acetate, stir to dissolve in the dark, then add 40mL modified graphene oxide aqueous dispersion (5mg / mL), stir for 30 minutes in the dark to obtain reaction mixture; (3) Functionalization treatment: Immerse the pretreated knitted fabric in the reaction mixture (bath ratio 1:20), and let it stand in a constant temperature water bath at 60℃ for 2 hours; (4) Posttreatment: Hot rinse at 80℃ for 10 minutes, cold rinse until the water is clear, and dry at 60℃.

[0029] The performance test results show that the functional knitted fabric has an antibacterial rate of ≥98.5% and a surface resistivity of ≤10. 8 Ω, after 50 washes, the antibacterial rate is ≥94%, maintaining the wrinkle resistance of polyester and the skin-friendliness of cotton.

[0030] Example 3 Experimental materials and equipment: Material: Nylon / Modal (50 / 50 weight ratio) blended yarn, total weight approximately 50g; Chemical reagents: dopamine acetate, graphene oxide aqueous dispersion (concentration 3 mg / mL), silver sulfate, borax-boric acid buffer, nonionic surfactant, deionized water; Main equipment: autoclave, constant temperature water bath shaker, etc.

[0031] Preparation steps (1) Pretreatment: Same as step (1) in Example 1; (2) Preparation of reaction solution: Prepare borax-boric acid buffer (pH=8.0), add 2.2g dopamine acetate, dissolve and add 0.15g silver sulfate, stir to dissolve in the dark, then add 60mL graphene oxide aqueous dispersion (3mg / mL), stir in the dark for 30 minutes to obtain reaction mixture; (3) Functionalization treatment: Immerse the pretreated yarn in the reaction mixture (bath ratio 1:20), place it in an autoclave, and react at 121℃ for 20 minutes; (4) Posttreatment: Hot rinse at 75℃ for 15 minutes, cold rinse until the water is clear, and dry at 55℃.

[0032] The performance test results show that the functional blended yarn has an antibacterial rate of ≥99% and a surface resistivity of ≤10. 7 Ω, with an antibacterial rate of ≥96% after 50 washes, retaining the strength of nylon and the softness of modal.

[0033] Summarize The above three embodiments comprehensively verified the technical solution of the present invention for different blended fiber combinations (polyester / bamboo viscose, polyester / cotton, nylon / modal), different types of reaction raw materials (dopamine salts, graphene oxide, silver salts), different reaction conditions (pH value, temperature, time), and different fabric forms (yarn, knitted fabric), and the following conclusions were drawn: The core technical solution of this invention has strong universality: regardless of whether the hydrophobic fiber in the blended yarn is polyester, nylon, etc., and the hydrophilic fiber is bamboo viscose, cotton, modal, etc., the functional coating can be precisely and selectively deposited on the surface of the hydrophilic fiber through the synergistic effect of "differential wetting kinetics" and "dopamine-mediated in-situ self-assembly". The hydrophobic fiber always remains in its original uncoated state, perfectly preserving the inherent comprehensive performance and style of the blended yarn.

[0034] The process parameters are flexible and adjustable: when the reaction pH value is adjusted within the range of 8.0 to 9.0, the reaction temperature within the range of room temperature to 121℃, and the reaction time within the range of 20 minutes to 3 hours, high-performance functional products can be stably prepared. Moreover, whether it is a mild water bath reaction condition or an efficient high-temperature and high-pressure reaction condition, it can meet the needs of different industrial production scenarios, further highlighting the simplicity and practicality of the process.

[0035] The products exhibit outstanding stability and versatility: all functional blended yarns and textiles prepared in the embodiments possess excellent antibacterial and antistatic properties. Some products also have additional functions such as UV protection and far-infrared health benefits due to the inherent properties of graphene and polydopamine. After 50 standard household washes, all functions remain at a high level, completely solving the core pain point of poor washability of functional textiles in the prior art.

[0036] The raw material selection and process design meet the requirements of industrialization: the raw materials used in the examples are all common chemicals that are readily available in the market, the reaction system is a green and environmentally friendly water system, without the use of strong acids, strong alkalis or organic solvents, and the post-processing only requires simple rinsing and drying steps. No complicated equipment is required, the production cost is low, the environment is friendly, and it is fully capable of large-scale industrial promotion.

[0037] In summary, the above embodiments fully demonstrate that the selective surface functionalization method provided by the present invention is stable and reliable, and the resulting functional blended yarns and textiles have excellent properties, which can meet the demand for high-end functional textile materials in multiple fields such as clothing, home textiles, and medical and health care. It effectively solves the technical bottlenecks in the existing functionalization treatment of blended yarns, such as non-selectivity, complex processes, and poor durability.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Those skilled in the art should understand that any modifications or equivalent substitutions made to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for selectively surface functionalizing hydrophilic fibers in blended yarns, characterized in that, Includes the following steps: Step a: Immerse the blended yarn in an aqueous reaction solution containing dopamine compounds, graphene oxide materials, and soluble silver salts; Step b: Adjust the pH of the aqueous reaction solution to weakly alkaline. Utilizing the characteristic that hydrophilic fibers are more easily wetted by the aqueous reaction solution than hydrophobic fibers in the blended yarn, the dopamine compounds preferentially undergo self-polymerization on the surface of the hydrophilic fibers, and simultaneously reduce the graphene oxide material to reduced graphene material, and reduce the silver ions in the soluble silver salt to silver nanoparticles. Step c: Under the set reaction conditions, a composite coating comprising polydopamine polymers, reduced graphene materials and silver nanoparticles is selectively formed on the surface of the hydrophilic fiber.

2. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, In step b, the pH value of the aqueous reaction solution is adjusted to 7.5–9.

5.

3. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, In step c, the set reaction conditions are: reaction temperature of room temperature (60℃~121℃) and reaction time of 10min~4h; When the reaction temperature is room temperature (60℃), the reaction time is 1–4 hours. When the reaction temperature is 121℃, the reaction time is 10 to 30 minutes.

4. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, The dopamine compounds include one or more of dopamine hydrochloride, dopamine sulfate, and dopamine acetate. The graphene oxide materials include one or more of graphene oxide and modified graphene oxide. The soluble silver salt includes one or more of silver nitrate, silver acetate, silver sulfate, silver lactate, and silver citrate.

5. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, The hydrophobic fiber includes one or more of polyester fiber, nylon, polypropylene, acrylic fiber, and vinylon. The hydrophilic fiber is a cellulose-based fiber, which includes one or more of cotton fiber, hemp fiber, viscose fiber, lyocell fiber, modal fiber, cupro fiber, and bamboo pulp fiber.

6. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, In step a, the aqueous reaction solution further comprises a buffer, which includes one or more of tris(hydroxymethyl)aminomethane buffer, ammonia-ammonium chloride buffer, and borax-boric acid buffer.

7. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, Before step a, there is also a step of pre-treating the blended yarn, which includes washing, rinsing and drying; The washing process uses an aqueous solution containing a surfactant, which is a nonionic surfactant.

8. The method for selectively surface functionalizing hydrophilic fibers in blended yarns according to claim 1, characterized in that, Step c is followed by hot rinsing, cold rinsing and drying; the hot rinsing temperature is 70-90°C and the rinsing time is 5-15 minutes.

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