Method for constructing MOF on the surface of cellulose fiber fabric in situ in one step

Abstract

The application belongs to the technical field of adsorbing materials, and relates to a method for constructing MOF on the surface of cellulose fiber fabric in situ in one step. 2+ or Fe 3+ ), a polyphenol and a phosphorus-containing flame retardant in an impregnating solution, removing the excess moisture on the surface of the cellulose fiber fabric, and baking to obtain the cellulose fiber fabric containing MOF on the surface; the phosphorus-containing flame retardant is provided with amino and / or hydroxyl groups; the concentration of the metal ion in the impregnating solution is not less than 0.1 g / L, and the concentration of the polyphenol is not less than 1 g / L; the impregnating temperature is not less than 40 DEG C; and the impregnating time is not less than 20 min. The application realizes the uniform and strong deposition of MOF on the surface of the fiber, ensures the interface stability, improves the heat resistance, flame retardation and weather resistance, and is simple to operate and easy to produce on a large scale.

Description

Technical Field

[0001] This invention belongs to the field of adsorption materials technology, specifically relating to a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics. Background Technology

[0002] Metal-organic frameworks (MOFs) are porous materials formed by coordination bonds between metal ions or clusters and organic ligands. They possess highly ordered structures and large specific surface areas, and their pore size can be precisely controlled by adjusting their composition. MOFs are widely used in gas storage, catalysis, sensing, and drug delivery, and exhibit good chemical and thermal stability. Cellulose fibers are natural polymers with excellent mechanical strength, biocompatibility, and biodegradability. The hydroxyl groups in cellulose molecules can bind to metal ions or ligands in MOFs to form stable composite materials.

[0003] Constructing MOFs on cellulose fiber fabrics can bring innovative applications to multiple fields, mainly involving the following aspects: ① By combining MOFs with cellulose fibers, the adsorption, filtration, and catalytic capabilities of the fibers can be improved, especially in water treatment and gas separation, where the efficiency of the composite material is significantly enhanced; ② In industrial catalysis, MOFs can be used as highly efficient catalysts or catalyst supports, while cellulose fibers as a substrate can provide good dispersibility and processability, making the catalytic process more efficient; ③ Due to their tunable pore size and biocompatibility, MOFs have already shown potential in drug delivery and medical imaging. Combining them with cellulose fibers can improve drug loading capacity and achieve controlled release; ④ Surface functionalization of MOFs can form various types of chemical bonds with the hydroxyl groups of cellulose, producing different surface activities, thereby adjusting the function of the composite material as needed.

[0004] Constructing MOFs on cellulose fiber fabrics presents two challenges that are difficult to address simultaneously:

[0005] (1) Most existing technologies first prepare MOF and then transfer MOF to the surface of cellulose fiber fabric through other processing methods. The bonding strength between MOF and cellulose fiber fabric is low, and the original moisture permeability and air permeability of the fabric will be destroyed.

[0006] (2) The product does not have heat resistance and superhydrophobicity, and cannot avoid structural degradation of MOF in humid or acidic / alkaline environments. For example, patent CN116043551B discloses a cotton fabric with antiviral bioactivity and its preparation method. First, the fabric is soaked in L-cysteine ​​solution and then heated for esterification to link L-cysteine ​​molecules to the fiber surface. The esterified fabric is then soaked in L-cysteine ​​solution again, and copper ion solution is added dropwise under stirring to induce the formation of L-cysteine / copper ion MOF structure on the surface of cotton fiber. The product obtained by this patent does not have heat resistance and superhydrophobicity.

[0007] Therefore, it is necessary to propose a new method for in-situ construction of MOFs on the surface of cellulose fiber fabrics to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to solve the above-mentioned problems and provide a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics involves immersing the cellulose fiber fabric in a solution containing metal ions, polyphenols (such as caffeic acid, gallic acid, chlorogenic acid, dopamine, etc.) and phosphorus-containing flame retardants. After removing excess moisture from the surface of the cellulose fiber fabric, it is baked to allow the metal ions, polyphenols, and phosphorus-containing flame retardants to form coordination bonds and self-assemble into MOFs, thus obtaining cellulose fiber fabrics with MOFs on the surface.

[0011] Phosphorus-containing flame retardants contain amino and / or hydroxyl groups, such as tetramethylphosphoric acid, ammonium polyphosphate, phytic acid, phosphonic acid derivatives containing amino and / or hydroxyl groups, etc.

[0012] In existing technologies, polyphenols are often simply used as ligands in the preparation of MOFs. This invention is the first to utilize the property that polyphenols can be oxidized into polymers by certain metal ions under acidic conditions. By using metal ions to oxidize polyphenols, polyphenol oligomers with a certain viscosity are formed, which helps metal ions and phosphorus-containing flame retardants to better adhere to the fiber surface, providing a good foundation for the subsequent formation of MOFs. It also helps MOFs to bond to the fabric surface, so that MOFs have good bonding strength and do not damage the original moisture permeability and breathability of the fabric.

[0013] The solution containing the metal ion Cu2+, polyphenols, and phosphorus-containing flame retardants has a pH of 4-6. Within this pH range, Cu2+ remains dissolved and effectively catalyzes the oxidation of polyphenols, generating quinone compounds, which then continue to polymerize. Cu2+ oxidizes polyphenols through a redox cycle (Cu2+ / Cu+). If the pH is greater than 6, Cu2+ combines with OH- to form Cu(OH)2 precipitate, losing its catalytic activity. If the pH is less than 4, although Cu2+ can remain dissolved, the oxidation rate of polyphenols may slow down because excessively high proton concentrations may inhibit the oxidation of polyphenols.

[0014] Alternatively, the solution containing Fe3+ metal ions, polyphenols, and phosphorus-containing flame retardants has a pH of 2-4. Within this pH range, Fe3+ can effectively catalyze the oxidation reaction of polyphenols and promote the polymerization reaction of polyphenols through the redox cycle (Fe3+ / Fe2+). If the pH is greater than 4, Fe3+ will rapidly hydrolyze to form Fe(OH)3 precipitate, leading to catalytic failure. If the pH is less than 2, although Fe3+ remains dissolved, the excessively high proton concentration may reduce the reaction rate and affect the catalytic efficiency.

[0015] In a solution containing metal ions, polyphenols, and phosphorus-containing flame retardants, the concentration of metal ions shall not be less than 0.1 g / L and the concentration of polyphenols shall not be less than 1 g / L. If the concentration of metal ions is too low, the amount of MOF generated will be insufficient due to the lack of metal ions. If the concentration of polyphenols is too low, the lack of polyphenols will result in ineffective coordination and unstable MOF structure.

[0016] The impregnation temperature should not be lower than 40℃. A suitable impregnation temperature can accelerate the oxidative polymerization reaction of polyphenols and help the initial coordination of metal ions with polyphenols. If the impregnation temperature is too low, the adsorption rate of metal ions, polyphenols and phosphorus-containing flame retardants on the fiber surface will slow down, which may lead to insufficient adsorption and affect the subsequent MOF formation.

[0017] The impregnation time should not be less than 20 minutes. The impregnation time not only needs to ensure that metal ions, polyphenols and phosphorus-containing flame retardants can be fully adsorbed by the fiber, but also needs to provide enough time for the oxidative polymerization reaction of polyphenols. If the impregnation time is too short, the oxidative polymerization process of polyphenols may not be completed, resulting in insufficient oligomers. This makes it difficult for metal ions and flame retardants to adhere evenly to the fiber surface, affecting the uniformity and performance of the subsequent MOF.

[0018] The cellulose fiber fabric with MOF on the surface obtained by the present invention has heat resistance and superhydrophobicity, which makes up for the shortcomings of the prior art. This is because the phosphorus flame retardant has good heat resistance, the water solubility of polyphenols decreases after polymerization or coordination with metal ions, the fabric surface has low surface energy, and the MOF on the fabric surface helps to form roughness.

[0019] As a preferred technical solution:

[0020] The method described above for in-situ construction of MOF on the surface of cellulose fiber fabric in a one-step process, wherein the concentration of metal ions is not higher than 1.5 g / L, the concentration of polyphenols is not higher than 5 g / L, and the concentration of phosphorus flame retardant is 0.5-3 g / L in a solution containing metal ions, polyphenols, and phosphorus flame retardants.

[0021] The concentration of metal ions should not be too high, otherwise it will cause the fiber surface to be deposited too thickly or unevenly, which may affect the feel and softness of the fabric.

[0022] The concentration of polyphenols should not be too high, otherwise it will lead to the formation of too many oligomers, forming a highly viscous surface layer, affecting the hand feel of the fabric, or even immersing or coating the generated MOF.

[0023] A concentration of 0.5-3 g / L for phosphorus-containing flame retardants ensures that the flame retardant can work together with metal ions and polyphenols to form a stable MOF coating, while giving the fabric good heat resistance and flame retardant properties. This avoids the inability to fully exert the flame retardant and heat resistance effect due to insufficient flame retardant, and also avoids the formation of an excessively thick phosphorus / phosphonate layer on the fabric surface due to excessive flame retardant, which would affect the softness and breathability of the fabric, and may even cause a decrease in mechanical properties.

[0024] The method described above for in-situ construction of MOF on the surface of cellulose fiber fabric in a one-step process involves a solution containing metal ions, polyphenols, and phosphorus-containing flame retardants, as well as hydrogen peroxide. The concentration of hydrogen peroxide is not higher than 0.1 g / L. Hydrogen peroxide can promote the rapid oxidation of polyphenols by metal ions. The concentration of hydrogen peroxide should not be too high, otherwise it will increase the oxidation risk of fibers and phosphorus-containing flame retardants.

[0025] The method described above for in-situ construction of MOF on the surface of cellulose fiber fabric in a one-step process involves a mass ratio of cellulose fiber fabric to a solution containing metal ions, polyphenols, and phosphorus-containing flame retardants of 1:10-20. This ensures that the solution can fully wet the fabric surface and distribute metal ions evenly. Excessive moisture will affect the deposition uniformity of MOF, leading to unstable performance, while insufficient moisture will affect the reaction environment and prevent the full formation of MOF.

[0026] As described above, the one-step method for in-situ construction of MOF on the surface of cellulose fiber fabric requires an impregnation temperature not exceeding 60°C. This avoids excessively high impregnation temperatures, which would accelerate the oxidation reaction rate of polyphenols, leading to the formation of excessive oligomers and affecting the stability and uniformity of the solution.

[0027] As described above, the one-step method for in-situ construction of MOF on the surface of cellulose fiber fabric should not exceed 60 minutes for immersion time. This avoids excessive accumulation of oligomers on the fiber surface due to excessive immersion time, which can lead to uneven surface, affect hand feel and MOF formation, and cause excessive water absorption by the fabric, affecting subsequent drying and baking steps.

[0028] The one-step method described above for in-situ MOF construction on the surface of cellulose fiber fabrics removes excess moisture from the surface of the cellulose fiber fabric. The residual moisture content in the cellulose fiber fabric is 60-80% of the fabric's mass. This avoids problems caused by excessive moisture removal, such as uneven chemical reactions (insufficient moisture on the fiber surface leads to uneven distribution, affecting the reaction efficiency of metal ions, polyphenols, and flame retardants; overly dry fibers cause the chemical reaction to occur faster or slower locally, ultimately affecting fabric performance), fiber embrittlement (under excessive drying, the cellulose structure may shrink and become embrittled, causing the fabric to lose mechanical strength and elasticity during subsequent processing), and reduced reaction efficiency (excessive residual moisture dilutes the surface chemical components, reducing the effective concentration of reactants and thus delaying the reaction), uneven deposition (if there is too much moisture, the deposition of chemicals on the fiber surface will be uneven, potentially leading to inconsistent distribution of polyphenols and metal ions, thus affecting MOF formation), and prolonged baking time (excessive humidity also increases subsequent drying and baking time, increases energy consumption, and may even cause fiber thermal damage).

[0029] The method described above for constructing MOFs in situ on the surface of cellulose fiber fabrics in one step involves baking at a temperature of 100-130℃. This avoids the degradation of cellulose fibers due to excessively high baking temperatures, which would affect the mechanical properties of the fabric (such as strength and flexibility), causing the fabric to yellow or become brittle. It also avoids insufficient crystallization of MOFs due to excessively low baking temperatures, which would lead to unstable MOF structures.

[0030] As described above, the one-step method for in-situ construction of MOF on the surface of cellulose fiber fabric involves a baking time of 30-60 minutes. This avoids the cellulose fibers becoming brittle or hardened due to excessive baking time, which would affect the fabric's feel and durability. It also avoids the MOF not being fully generated and cured due to insufficient baking time, which would affect its stability and adhesion on the fiber surface.

[0031] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step as described in any of the preceding items, wherein the MOF of the cellulose fiber fabric containing MOF on the surface is a regular cubic structure;

[0032] Cellulose fiber fabrics with MOF on the surface have a limiting oxygen index of ≥28% and a thermal decomposition temperature of 250-320℃, which is more than 10% higher than the original fabric. They have excellent heat resistance and flame retardant properties, partly due to the good heat resistance and flame retardant properties of phosphorus flame retardants, and partly due to the certain flame retardant properties of MOF itself.

[0033] Cellulose fiber fabrics with MOF on the surface have a water contact angle ≥160° and a water adhesion force ≤28.49μN. They have superhydrophobic and self-cleaning properties, which can prevent stains or other reagents from contaminating and damaging the MOF structure. This is because the water solubility of polyphenols decreases after polymerization or coordination with metal ions, and the fabric surface has low surface energy. The MOF on the fabric surface helps to form roughness.

[0034] The moisture permeability (representing the amount of water vapor passing through a unit area per unit time) of cellulose fiber fabrics containing MOF on the surface is ≥2200 g / (m²). 2 •day), air permeability (representing the amount of air passing through a unit area per unit time) ≥150m³ 3 / (m 2 •h) It has good moisture permeability and breathability because the polyphenol oligomers are at the molecular level and rely on hydrogen bonds to bind MOF and fabric. The scale is within 10nm, which is a molecular layer coating.

[0035] Abrasion loss of cellulose fiber fabrics with MOF on the surface ≤10g / 100cm 2 The wear cycle count is over 3500, and both the longitudinal and transverse tear strengths are ≥30N, under an irradiation intensity of 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decrease rate is ≤15%. After 72 hours of exposure at 70℃ and 90% relative humidity, the tensile strength decrease rate is ≤25%. It exhibits excellent abrasion resistance, tear resistance, and durability under harsh conditions. This is because the oligomerization reaction of polyphenols not only provides viscosity but also further enhances the mechanical strength of the fiber by forming a dense cross-linked network.

[0036] After 50 washes, the change rate of each index of cellulose fiber fabric containing MOF on the surface does not exceed 10%, which shows that the bonding strength between MOF and cellulose fiber fabric is high. This is because polyphenol oligomers can help MOF adhere to the fabric surface.

[0037] In the large-scale synthesis of MOFs, uneven deposition of MOFs on the fiber surface during industrial production can affect the overall performance of the material, preventing it from achieving the desired functionality. Therefore, maintaining a uniform distribution of MOFs and consistent material properties on large-area cellulose fiber fabrics is a significant challenge.

[0038] To address this challenge, this invention proposes a simple impregnation-baking method. This method not only eliminates the need for complex equipment but is also easily scalable in industrial production, making it particularly suitable for processing large-area fabrics. Compared to other MOF synthesis processes (such as solvothermal or vapor deposition methods), the impregnation-baking method offers advantages such as low temperature, ease of operation, and low energy consumption, making it ideal for large-scale production operations in factories.

[0039] In the impregnation-baking process, polyphenols and polyphenolic compounds play a crucial role as chelating agents. They not only coordinate with metal ions but also help control the uniform distribution of metal ions and flame retardants on the fiber surface. This chelating effect ensures uniform deposition of MOFs on the fiber surface, avoiding the problem of localized over-deposition or precipitation, thereby greatly improving the controllability of MOF synthesis and the consistency of materials, especially in terms of uniformity on large-area fabrics.

[0040] Furthermore, after impregnation, the present invention removes excess moisture from the fabric surface by centrifugation or pressing, controlling the moisture content between 60-80%. This step ensures a uniform distribution of chemical components on the fiber surface. Subsequent heat treatment further ensures that the MOF can crystallize stably and deposit uniformly on the fiber surface. This heating strategy not only effectively controls the crystallization process of the MOF but also ensures the consistency of material properties during large-scale production.

[0041] Beneficial effects:

[0042] The present invention discloses a one-step in-situ method for constructing MOFs on the surface of cellulose fiber fabrics. Through the synergistic effect of polyphenols, metal ions and phosphorus-containing flame retardants, the synthesis process of MOFs is simplified, and uniform deposition and strong bonding are achieved on the fiber surface. The viscous oligomers generated by polyphenols under catalytic conditions enhance the adhesion of MOFs to cellulose, ensuring the stability of interfacial bonding, while endowing the material with good heat resistance, flame retardancy and weather resistance.

[0043] The present invention provides a one-step in-situ method for constructing MOFs on the surface of cellulose fiber fabrics. This method is simple to operate, easy to scale up, and suitable for the functionalization of large-area textile materials. It overcomes the problems of insufficient interfacial bonding and poor environmental stability in traditional MOF processes, and provides an efficient and sustainable solution for improving the functionality of textile materials. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0045] The detection methods for the relevant indicators are as follows:

[0046] Limiting oxygen index: GB / T 5454-1997 "Test for flammability of textiles - Oxygen index method";

[0047] Thermal decomposition temperature: GB / T 37631-2019 "Test Method for Thermal Decomposition Temperature of Chemical Fibers";

[0048] Water contact angle: GB / T 42694-2023 "Test and evaluation of the anti-wetting properties of textile surfaces - contact angle and roll-off angle method";

[0049] Water adhesion force: The contact angle and the length of the contact line between the water droplet and the fabric surface were measured using GB / T 42694-2023 "Test and evaluation of the anti-wetting properties of textile surfaces - contact angle and roll-off angle method". The adhesion force value F = γ·L·(1+cosθ), where F is the water adhesion force value in μN (micronewtons); γ is the surface tension of water, typically 7.28 × 10⁻⁶. -2 N / m (under standard conditions at 20℃); θ: contact angle of water droplet on material surface, in degrees (°); L: contact line length between water droplet and fabric surface (μm).

[0050] Moisture permeability: GB / T 12704.2-2009 "Textiles - Test methods for moisture permeability of fabrics - Part 2: Evaporation method";

[0051] Air permeability: GB / T 5453-1997 "Determination of air permeability of textile fabrics";

[0052] Abrasion loss: GB / T 21196.3-2007 "Textiles - Martindale Method for Determination of Abrasion Resistance of Fabrics - Part 3: Determination of Mass Loss";

[0053] Wear cycles: GB / T 21196.2-2007 "Textiles - Martindale Method - Determination of Abrasion Resistance of Fabrics - Part 2: Determination of Specimen Breakage";

[0054] Longitudinal and transverse tear strength: GB / T 3917.3-2009 "Textiles - Tear Properties of Fabrics - Part 3: Determination of Tear Strength of Trapezoidal Specimens";

[0055] Strength reduction rate: GB / T 3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)", the tensile strength is measured before and after UV aging, and the percentage reduction in strength is calculated;

[0056] Tensile strength reduction rate: GB / T 3923.1-2013 "Textiles - Tensile properties of fabrics - Part 1: Determination of breaking strength and elongation at break (strip method)", measure the change in tensile strength before and after high temperature and high humidity treatment, and calculate the percentage reduction in tensile strength;

[0057] Washing: ISO 105C06 "Color fastness to washing".

[0058] Example 1

[0059] The specific steps of a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics are as follows:

[0060] (1) Prepare the raw materials:

[0061] water;

[0062] CuSO4;

[0063] Polyphenols: Caffeic acid;

[0064] Phosphorus-containing flame retardant: tetrahydroxymethylphosphorus chloride;

[0065] Cellulose fiber fabrics: Cotton fiber fabrics;

[0066] (2) Prepare the impregnation solution:

[0067] CuSO4, polyphenols, phosphorus-containing flame retardants and water are mixed evenly and the pH of the system is adjusted to 4 to obtain an impregnation solution containing metal ions, polyphenols and phosphorus-containing flame retardants.

[0068] The impregnation solution contains 0.1 g / L of metal ions, 1 g / L of polyphenols, and 0.5 g / L of phosphorus-containing flame retardant.

[0069] (3) Soaking and baking:

[0070] After immersing the cellulose fiber fabric in an impregnation solution at 40°C for 25 minutes, removing excess moisture from the surface of the cellulose fiber fabric, and baking at 110°C for 40 minutes, a cellulose fiber fabric with MOF on the surface is obtained.

[0071] The mass ratio of cellulose fiber fabric to impregnation solution is 1:15. After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 70% of the mass of the cellulose fiber fabric.

[0072] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 28%, the thermal decomposition temperature is 250℃, the water contact angle is 160°, the water adhesion force is 28.49 μN, and the moisture permeability is 2554 g / (m²). 2 (day), breathability is 186m 3 / (m 2 The wear loss is 7.9 g / 100 cm (·h). 2 The wear cycle count was 3700, the longitudinal tear strength was 34N, and the transverse tear strength was 33N, under an irradiation intensity of 0.35W / m. 2After 500 hours of ultraviolet irradiation, the strength decreased by 13%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 22%. After 50 water washes, the change rate of each index did not exceed 10%.

[0073] Comparative Example 1

[0074] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 1, except that the pH of the system is adjusted to 3 in step (2).

[0075] The resulting cellulose fiber fabric with MOF-containing surface exhibits a limiting oxygen index of 27%, a thermal decomposition temperature of 220℃, a water contact angle of 145°, a water adhesion strength of 28.96 μN, and a moisture permeability of 2568 g / (m²). 2 (day), breathability is 190m 3 / (m 2 The wear loss is 8.3 g / 100 cm (·h). 2 The wear cycle count was 3350, the longitudinal tear strength was 30N, and the transverse tear strength was 29N, under an irradiation intensity of 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 15%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 25%. After 50 water washes, the maximum change rate of each indicator was 12%.

[0076] Comparing Example 1 with Comparative Example 1, it can be seen that the flame retardancy and heat resistance of the fabric in Comparative Example 1 are reduced, the moisture permeability and air permeability are slightly increased, the abrasion resistance is reduced, the tear strength is reduced, and the physical and mechanical properties are reduced after ultraviolet irradiation and high temperature and humidity treatment. This is because when the pH value is less than 4, although Cu2+ can remain in a dissolved state, the oxidation rate of polyphenols may be slowed down, as excessively high proton concentration may inhibit the oxidation of polyphenols.

[0077] Comparative Example 2

[0078] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 1, except that the concentration of polyphenols in step (2) is 0.5 g / L.

[0079] The resulting cellulose fiber fabric with MOF-containing surface exhibits a limiting oxygen index of 25%, a thermal decomposition temperature of 200℃, a water contact angle of 123°, a water adhesion strength of 29.14 μN, and a moisture permeability of 2624 g / (m²). 2 (day), breathability is 192m 3 / (m 2 The wear loss is 8.5 g / 100 cm (·h). 2The wear cycle count was 3100, the longitudinal tear strength was 27 N, and the transverse tear strength was 28 N, under an irradiation intensity of 0.35 W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 17%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 26%. After 50 water washes, the maximum change rate of each indicator was 14%.

[0080] Comparing Example 1 with Comparative Example 2, it can be seen that the flame retardancy and heat resistance of the fabric in Comparative Example 2 are reduced, the moisture permeability and air permeability are slightly increased, the abrasion resistance is reduced, the tear strength is reduced, and the physical and mechanical properties are reduced after ultraviolet irradiation and high temperature and humidity treatment. This is because the concentration of polyphenols is too low. Due to the lack of polyphenols, effective coordination is not possible, and the MOF structure is unstable.

[0081] Example 2

[0082] The specific steps of a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics are as follows:

[0083] (1) Prepare the raw materials:

[0084] water;

[0085] CuCl2;

[0086] Polyphenols: Gallic acid;

[0087] Phosphorus-containing flame retardant: ammonium polyphosphate, degree of polymerization 10;

[0088] Cellulose fiber fabrics: Viscose fiber fabrics;

[0089] (2) Prepare the impregnation solution:

[0090] CuCl2, polyphenols, phosphorus-containing flame retardants, and water are mixed evenly and the pH of the system is adjusted to 5 to obtain an impregnation solution containing metal ions, polyphenols, and phosphorus-containing flame retardants.

[0091] The impregnation solution contains 0.5 g / L of metal ions, 2 g / L of polyphenols, and 1 g / L of phosphorus-containing flame retardant.

[0092] (3) Soaking and baking:

[0093] After immersing the cellulose fiber fabric in an impregnation solution at 50°C for 40 minutes, removing excess moisture from the surface of the cellulose fiber fabric, and baking at 120°C for 45 minutes, a cellulose fiber fabric with MOF on the surface is obtained.

[0094] The mass ratio of cellulose fiber fabric to impregnation solution is 1:10. After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 60% of the mass of the cellulose fiber fabric.

[0095] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 28.4%, the thermal decomposition temperature is 266℃, the water contact angle is 163°, the water adhesion force is 28.35 μN, and the moisture permeability is 2456 g / (m²). 2 (day), breathability is 175m 3 / (m 2 The wear loss is 7.6 g / 100 cm (·h). 2 The wear cycle count was 4200, the longitudinal tear strength was 35N, and the transverse tear strength was 36N, under an irradiation intensity of 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 10%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 18%. After 50 water washes, the change rate of each indicator did not exceed 10%.

[0096] Example 3

[0097] The specific steps of a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics are as follows:

[0098] (1) Prepare the raw materials:

[0099] water;

[0100] FeCl3;

[0101] Polyphenols: Chlorogenic acid;

[0102] Phosphorus-containing flame retardant: phytic acid;

[0103] Cellulose fiber fabrics: Ramie fiber fabrics;

[0104] (2) Prepare the impregnation solution:

[0105] FeCl3, polyphenols, phosphorus-containing flame retardants and water are mixed evenly and the pH of the system is adjusted to 2 to obtain an impregnation solution containing metal ions, polyphenols and phosphorus-containing flame retardants.

[0106] The impregnation solution contains 0.8 g / L of metal ions, 3 g / L of polyphenols, and 1.5 g / L of phosphorus-containing flame retardant.

[0107] (3) Soaking and baking:

[0108] After immersing the cellulose fiber fabric in an impregnation solution at 40°C for 20 minutes, removing excess moisture from the surface of the cellulose fiber fabric, and baking at 100°C for 30 minutes, a cellulose fiber fabric with MOF on the surface is obtained.

[0109] The mass ratio of cellulose fiber fabric to impregnation solution is 1:20. After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 80% of the mass of the cellulose fiber fabric.

[0110] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 28.6%, the thermal decomposition temperature is 274℃, the water contact angle is 162°, the water adhesion force is 28.12 μN, and the moisture permeability is 2348 g / (m²). 2 (day), breathability is 168m 3 / (m 2 The wear loss is 9.6 g / 100 cm (·h). 2 The wear cycle count is 3500, the longitudinal tear strength is 30N, the transverse tear strength is 30N, and the irradiation intensity is 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 15%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 25%. After 50 water washes, the change rate of each indicator did not exceed 10%.

[0111] Comparative Example 3

[0112] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 3, except that the pH of the system is adjusted to 1 in step (2).

[0113] The final cellulose fiber fabric with MOF-containing surface exhibits a limiting oxygen index of 25.3%, a thermal decomposition temperature of 198℃, a water contact angle of 132°, a water adhesion strength of 29.31 μN, and a moisture permeability of 2421 g / (m²). 2 (day), breathability is 172m 3 / (m 2 The wear loss is 10.2 g / 100 cm (·h). 2 The wear cycle count was 2850, the longitudinal tear strength was 25 N, and the transverse tear strength was 26 N, under an irradiation intensity of 0.35 W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 23%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 29%. After 50 water washes, the maximum change rate of each indicator was 18%.

[0114] Comparing Example 3 with Comparative Example 3, it can be seen that the flame retardancy and heat resistance of the fabric in Comparative Example 3 are reduced, the moisture permeability and air permeability are slightly increased, the abrasion resistance is reduced, the tear strength is reduced, and the physical and mechanical properties are reduced after ultraviolet irradiation and high temperature and humidity treatment. This is because the pH value is less than 2. Although Fe3+ remains dissolved, the excessively high proton concentration may reduce the reaction rate and affect the catalytic efficiency.

[0115] Comparative Example 4

[0116] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 3, except that the immersion temperature in step (3) is 35°C.

[0117] The final cellulose fiber fabric with MOF-containing surface exhibits a limiting oxygen index of 26.1%, a thermal decomposition temperature of 206℃, a water contact angle of 135°, a water adhesion strength of 28.97 μN, and a moisture permeability of 2384 g / (m²). 2 (day), breathability is 170m 3 / (m 2 The wear loss is 9.9 g / 100 cm (·h). 2 The wear cycle count was 3100, the longitudinal tear strength was 27 N, and the transverse tear strength was 26 N, under an irradiation intensity of 0.35 W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 17%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 27%. After 50 water washes, the maximum change rate of each indicator was 15%.

[0118] Comparing Example 3 with Comparative Example 4, it can be seen that the flame retardancy and heat resistance of the fabric in Comparative Example 4 are reduced, the moisture permeability and air permeability are slightly increased, the abrasion resistance is reduced, the tear strength is reduced, and the physical and mechanical properties are reduced after ultraviolet irradiation and high temperature and humidity treatment. This is because the impregnation temperature is too low, which slows down the adsorption rate of metal ions, polyphenols and phosphorus-containing flame retardants on the fiber surface, which may lead to insufficient adsorption and affect the subsequent MOF formation.

[0119] Comparative Example 5

[0120] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 3, except that the immersion time in step (3) is 15 min.

[0121] The final cellulose fiber fabric with MOF-containing surface exhibits a limiting oxygen index of 25.9%, a thermal decomposition temperature of 201℃, a water contact angle of 130°, a water adhesion strength of 30.01 μN, and a moisture permeability of 2398 g / (m²). 2 (day), breathability is 171m3 / (m 2 The wear loss is 10.1 g / 100 cm (·h). 2 The wear cycle count was 2900, the longitudinal tear strength was 28 N, and the transverse tear strength was 27 N, under an irradiation intensity of 0.35 W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 19%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 28%. After 50 water washes, the maximum change rate of each indicator was 16%.

[0122] Comparing Example 3 with Comparative Example 5, it can be seen that the flame retardancy and heat resistance of the fabric in Comparative Example 5 are reduced, the moisture permeability and air permeability are slightly increased, the abrasion resistance is reduced, the tear strength is reduced, and the physical and mechanical properties are reduced after ultraviolet irradiation and high temperature and humidity treatment. This is because if the impregnation time is too short, the oxidative polymerization process of polyphenols may not be completed, and the generated oligomers are insufficient, which makes it difficult for metal ions and flame retardants to adhere evenly to the fiber surface, affecting the uniformity and performance of the subsequent MOF.

[0123] Example 4

[0124] The specific steps of a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics are as follows:

[0125] (1) Prepare the raw materials:

[0126] water;

[0127] Fe2(SO4)3;

[0128] Polyphenols: Dopamine;

[0129] Phosphorus-containing flame retardant: ethylenediaminetetramethylenephosphonic acid;

[0130] Cellulose fiber fabrics: Lyocell fiber fabrics;

[0131] (2) Prepare the impregnation solution:

[0132] Fe2(SO4)3, polyphenols, phosphorus-containing flame retardants and water are mixed evenly and the pH of the system is adjusted to 4 to obtain an impregnation solution containing metal ions, polyphenols and phosphorus-containing flame retardants.

[0133] The impregnation solution contains 1.2 g / L of metal ions, 4 g / L of polyphenols, and 2 g / L of phosphorus-containing flame retardant.

[0134] (3) Soaking and baking:

[0135] After immersing the cellulose fiber fabric in an impregnation solution at 45°C for 30 minutes, removing excess moisture from the surface of the cellulose fiber fabric, and baking at 105°C for 35 minutes, a cellulose fiber fabric with MOF on the surface is obtained.

[0136] The mass ratio of cellulose fiber fabric to impregnation solution is 1:18. After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 75% of the mass of the cellulose fiber fabric.

[0137] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 29.2%, the thermal decomposition temperature is 286℃, the water contact angle is 165°, the water adhesion force is 27.63 μN, and the moisture permeability is 2314 g / (m²). 2 (day), breathability is 163m 3 / (m 2 The wear loss is 8.4 g / 100 cm (·h). 2 The wear cycle count was 3600, the longitudinal tear strength was 32N, and the transverse tear strength was 33N, under an irradiation intensity of 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 12%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 24%. After 50 water washes, the change rate of each indicator did not exceed 10%.

[0138] Example 5

[0139] The specific steps of a one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics are as follows:

[0140] (1) Prepare the raw materials:

[0141] water;

[0142] Cu(NO3)2;

[0143] Polyphenols: Caffeic acid;

[0144] Phosphorus-containing flame retardant: ethylenediaminetetramethylenephosphonic acid;

[0145] Cellulose fiber fabrics: Tencel fiber fabrics;

[0146] (2) Prepare the impregnation solution:

[0147] Cu(NO3)2, polyphenols, phosphorus-containing flame retardants and water are mixed evenly and the pH of the system is adjusted to 6 to obtain an impregnation solution containing metal ions, polyphenols and phosphorus-containing flame retardants.

[0148] The impregnation solution contains 1.5 g / L of metal ions, 5 g / L of polyphenols, and 3 g / L of phosphorus-containing flame retardant.

[0149] (3) Soaking and baking:

[0150] After immersing the cellulose fiber fabric in an impregnation solution at 60°C for 60 minutes, removing excess moisture from the surface of the cellulose fiber fabric, and baking at 130°C for 60 minutes, a cellulose fiber fabric with MOF on the surface is obtained.

[0151] The mass ratio of cellulose fiber fabric to impregnation solution is 1:20. After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 75% of the mass of the cellulose fiber fabric.

[0152] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 29.5%, the thermal decomposition temperature is 288℃, the water contact angle is 163°, the water adhesion force is 27.91 μN, and the moisture permeability is 2297 g / (m²). 2 (day), breathability is 154m 3 / (m 2 The wear loss is 9.1 g / 100 cm (·h). 2 The wear cycle count was 3900, the longitudinal tear strength was 33N, the transverse tear strength was 33N, and the irradiation intensity was 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 13%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 23%. After 50 water washes, the change rate of each indicator did not exceed 10%.

[0153] Example 6

[0154] The method for constructing MOF in situ on the surface of cellulose fiber fabric in one step is basically the same as in Example 5, except that the impregnation solution prepared in step (2) of this example also contains hydrogen peroxide at a concentration of 0.05 g / L.

[0155] The resulting cellulose fiber fabric with MOF on its surface has a regular cubic MOF structure. The limiting oxygen index of the MOF-containing cellulose fiber fabric is 30.1%, the thermal decomposition temperature is 320℃, the water contact angle is 167°, the water adhesion force is 27.61 μN, and the moisture permeability is 2200 g / (m²). 2 (day), breathability is 150m 3 / (m 2 •h), wear loss is 10g / 100cm 2The wear cycle count was 3700, the longitudinal tear strength was 32N, and the transverse tear strength was 31N, under an irradiation intensity of 0.35W / m. 2 After 500 hours of ultraviolet irradiation, the strength decreased by 14%. After 72 hours of exposure at 70°C and 90% relative humidity, the tensile strength decreased by 24%. After 50 water washes, the change rate of each indicator did not exceed 10%.

Claims

1. A one-step method for in-situ construction of MOFs on the surface of cellulose fiber fabrics, characterized in that, After immersing the cellulose fiber fabric in a solution containing metal ions, polyphenols and phosphorus flame retardants, the excess moisture on the surface of the cellulose fiber fabric is removed, and then it is baked to obtain a cellulose fiber fabric with MOF on the surface. Phosphorus-containing flame retardants contain amino and / or hydroxyl groups; The solution containing Cu²⁺ metal ions, polyphenols, and phosphorus-containing flame retardants has a pH value of 4-6. Alternatively, the solution containing Fe³⁺ metal ions, polyphenols, and phosphorus-containing flame retardants has a pH value of 2-4. In a solution containing metal ions, polyphenols, and phosphorus-containing flame retardants, the concentration of metal ions is 0.1-1.5 g / L, the concentration of polyphenols is 1-5 g / L, and the concentration of phosphorus-containing flame retardants is 0.5-3 g / L. The immersion temperature shall not be lower than 40°C; The soaking time shall not be less than 20 minutes.

2. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, The solution also contains metal ions, polyphenols, and phosphorus-containing flame retardants, and contains hydrogen peroxide, with a concentration not exceeding 0.1 g / L.

3. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, The mass ratio of cellulose fiber fabric to a solution containing metal ions, polyphenols, and phosphorus-containing flame retardants is 1:10-20.

4. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, The immersion temperature should not exceed 60°C.

5. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, The soaking time should not exceed 60 minutes.

6. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, After removing excess moisture from the surface of the cellulose fiber fabric, the residual moisture in the cellulose fiber fabric is 60-80% of the mass of the cellulose fiber fabric.

7. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, The baking temperature is 100-130°C.

8. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to claim 1, characterized in that, Baking time is 30-60 minutes.

9. The method for in-situ construction of MOF on the surface of cellulose fiber fabric in one step according to any one of claims 1 to 8, characterized in that, The MOFs in cellulose fiber fabrics containing MOFs on their surface have a regular cubic structure. Cellulose fiber fabrics with MOF on the surface have a limiting oxygen index ≥28% and a thermal decomposition temperature of 250-320℃. Cellulose fiber fabrics with MOF on the surface have a water contact angle ≥160° and a water adhesion force ≤28.49μN; Cellulose fiber fabrics with MOF on the surface have a moisture permeability ≥2200g / (m²·day) and an air permeability ≥150m³ / (m²·h). Cellulose fiber fabrics with MOF on the surface exhibit abrasion loss ≤10g / 100cm², abrasion cycles exceeding 3500, longitudinal and transverse tear strengths ≥30N, strength reduction rate ≤15% after 500h of UV irradiation at 0.35W / m², and tensile strength reduction rate ≤25% after 72h of exposure at 70°C and 90% relative humidity. Cellulose fiber fabrics with MOF on the surface show a change rate of no more than 10% in each indicator after 50 washes.