Method for preparing durable anti-ultraviolet fabric through tannic acid / nano-zinc oxide composite functional finishing

Abstract

The invention relates to a method for preparing durable anti-ultraviolet fabric by adopting tannic acid / nano-zinc oxide composite functional finishing, which comprises the following steps: step 1, sequentially adding tannic acid and a sodium hydroxide solution into a zinc chloride solution in a stirring state to prepare a tannic acid and zinc hydroxide composite finishing solution, the molar ratio of the added zinc chloride, sodium hydroxide and tannic acid is 50: 100: (1-4), putting the linen fabric into the tannic acid and zinc hydroxide composite finishing liquid for finishing, and then taking out and drying the linen fabric. And 2, soaking the fabric finished in the step 1 in a tannic acid solution (the pH value is 7.5-12) at room temperature, taking out and drying. The modification method provided by the invention can effectively improve the ultraviolet resistance and washing resistance of the finished fabric.

Description

Technical Field

[0001] This invention relates to a fabric functional finishing technology, and more specifically, to a method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing. Background Technology

[0002] Hemp fiber is a natural cellulose fiber, characterized by its ruggedness, coolness, breathability, rapid moisture absorption and dissipation, and antibacterial properties. It is also renewable and biodegradable, making it a green functional fiber. While hemp fiber boasts high strength, its coarseness and low elongation at break negatively impact its performance in clothing and limit its applications.

[0003] Ammonia is a colorless, pungent, and toxic gas. High concentrations of ammonia can directly threaten human health and cause environmental pollution. Ammonia can also form explosive mixtures with air, igniting and exploding upon contact with open flames or high temperatures. Monitoring ammonia can alert to leaks, preventing harm to public health, and can also quickly indicate spoilage risks by detecting ammonia release from meat, shrimp, crab, and other products. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing durable UV-resistant fabrics by using a tannic acid / nano zinc oxide composite functional finishing process, which addresses the above-mentioned shortcomings.

[0005] The technical solution of the present invention is as follows: A method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing process includes the following steps: A method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing process includes the following steps: Step 1: Tannic acid-assisted in-situ formation and finishing of nano-zinc oxide: Prepare a zinc chloride solution of a certain concentration, stir with a magnetic stirrer, then add tannic acid solution dropwise with a dropper while stirring for 10 minutes. Next, slowly add a certain volume of sodium hydroxide solution and continue stirring for 10 minutes. Immerse the fabric in the finishing solution, then remove and dry it. Step 2, Post-treatment after tannic acid film formation: Immerse the fabric treated in Step 1 in a tannic acid solution at room temperature, then remove and dry. Furthermore, in step 1, the concentration of zinc chloride solution is 1-40 g / L, the concentration of tannic acid solution is 1-35 g / L, the concentration of sodium hydroxide is 1-40 g / L, and the molar ratio of zinc chloride:sodium hydroxide:tannic acid is 50:100:(1-4).

[0006] Furthermore, in step 1, the finishing temperature is 60-100℃, and the finishing time is 5-120 min. Furthermore, in step 2, the tannic acid solution concentration is 1-10 g / L, the soaking time is 12-60 h, and the pH value is 7.5-11.

[0007] The beneficial effects of this invention are that the finished fabric has the following advantages: (1) Excellent UV resistance Fabrics treated using the method of this invention exhibit excellent UV resistance. The UV protection factor (UPF) of the treated ramie fabric exceeds 50, significantly higher than that of the untreated ramie fabric. In this invention, the first step employs a tannic acid-controlled in-situ generation finishing technology for nano-zinc oxide fabrics. The core principle is as follows: zinc chloride and sodium hydroxide react to generate zinc hydroxide colloid. After the fabric is immersed in the finishing solution, the zinc hydroxide adheres to the fabric. During drying, the zinc hydroxide adhering to the fabric decomposes into nano-zinc oxide, achieving in-situ generation of nano-zinc oxide on the fabric, thereby endowing the fabric with UV resistance. In this process, the addition of tannic acid enhances the UV resistance of the finished fabric. Tannic acid plays two main roles: firstly, tannic acid itself possesses natural UV-resistant activity, and adding it to the finishing solution directly adds UV protection to the fabric; secondly, the phenolic hydroxyl groups in the tannic acid molecule can chelate with zinc ions, effectively dispersing zinc ions in the zinc chloride solution and preventing the aggregation of zinc hydroxide and in-situ generated nano-zinc oxide particles generated in subsequent reactions, resulting in smaller size, more uniform dispersion, and better penetration into the ramie fabric for even adhesion. The second step, tannic acid film-forming post-treatment, further enhances the UV resistance by coating the nano-zinc oxide finishing solution with a layer of tannic acid film.

[0008] (2) Good washability Fabrics treated by the method of this invention retain excellent UV resistance even after multiple washes. After 20 washes, the UV resistance of the treated fabric did not decrease, and the UPF value remained above 50, indicating that the treatment process imparts good wash resistance to the fabric. The second step of this invention employs a tannic acid film-forming post-treatment. Under weakly alkaline conditions, tannic acid undergoes oxidative self-polymerization, forming a dense and stable tannic acid film on the surface of the fabric treated with nano-zinc oxide. This film effectively coats the nano-zinc oxide particles on the fabric, preventing them from falling off during washing, thus ensuring the durability of the UV resistance function. Detailed Implementation

[0009] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0010] Based on the information contained in this application, various changes to the precise description of the invention can be readily made by those skilled in the art without departing from the spirit and scope of the appended claims. It should be understood that the scope of the invention is not limited to the defined processes, properties, or components, as these embodiments and other descriptions are merely illustrative of specific aspects of the invention. In fact, various modifications to embodiments of the invention that will be apparent to those skilled in the art or related fields are covered within the scope of the appended claims.

[0011] To better understand the invention and not to limit its scope, all figures indicating amounts, percentages, and other numerical values ​​used in this application should, in all cases, be understood to be modified by the word "approximately." Therefore, unless specifically stated otherwise, the numerical parameters listed in the specification and appended claims are approximate values ​​and may vary depending on the desired properties being sought. Each numerical parameter should at least be considered as obtained based on reported significant figures and through conventional rounding methods. Example

[0012] This embodiment describes a method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing process. The method includes the following steps: Step 1: Tannic acid-assisted in-situ preparation of nano-zinc oxide: Dissolve 0.34g of zinc chloride in 20ml of water to prepare 20mL of a 17g / L zinc chloride solution. Dissolve 0.15g of tannic acid in 10ml of water to prepare a 15g / L tannic acid solution. Dissolve 0.02g of sodium hydroxide in 20ml of water to prepare a 10g / L sodium hydroxide solution. Stir 20mL of the 17g / L zinc chloride solution with a magnetic stirrer. Then, add 10mL of the 15g / L tannic acid solution dropwise with a dropper while stirring for 10min. Next, slowly add 20mL of the 10g / L sodium hydroxide solution and continue stirring for 10min to prepare the finishing solution. Weigh 1g of fabric and immerse it in the finishing solution at 80℃ for 15min, then remove and dry. Step 2, post-treatment of tannic acid film formation: Add 0.125g of tannic acid to 50ml of water to prepare a 2.5g / L tannic acid solution. Then adjust the pH to 7.8 with sodium hydroxide solution to prepare a tannic acid finishing solution. Place the fabric treated in Step 1 into the tannic acid finishing solution and let it stand at room temperature for 24 hours before taking it out and drying it.

[0013] Comparative Example 1: Tannic acid-assisted in-situ formation and finishing of nano-zinc oxide: 0.34g of zinc chloride was dissolved in 20ml of water to prepare 20mL of a 17g / L zinc chloride solution. 0.15g of tannic acid was dissolved in 10ml of water to prepare a 15g / L tannic acid solution. 0.02g of sodium hydroxide was dissolved in 20ml of water to prepare a 10g / L sodium hydroxide solution. 20mL of the 17g / L zinc chloride solution was stirred with a magnetic stirrer. Then, 10mL of the 15g / L tannic acid solution was added dropwise with a dropper while stirring for 10min. Next, 20mL of the 10g / L sodium hydroxide solution was slowly added dropwise while stirring for another 10min to prepare the finishing solution. 1g of fabric was weighed and placed in the finishing solution, treated at 80℃ for 15min, then removed and dried. Comparative Example 2: In-situ Preparation of Nano-Zinc Oxide: 0.34g of zinc chloride was dissolved in 20ml of water to prepare 20mL of a 17g / L zinc chloride solution. 0.02g of sodium hydroxide was dissolved in 20ml of water to prepare a 10g / L sodium hydroxide solution. The 20mL of the 17g / L zinc chloride solution was stirred with a magnetic stirrer. Then, 10mL of pure water was added dropwise with a dropper while stirring for 10min. Next, 20mL of the 10g / L sodium hydroxide solution was slowly added dropwise while stirring for another 10min to prepare the finishing solution. 1g of fabric was weighed and placed in the finishing solution, treated at 80℃ for 15min, then removed and dried. Control group: Ramie fabric.

[0014] The UV resistance of the above-mentioned linen fabrics was tested, and the fabrics were washed 20 times before the UV resistance was tested again. The results are shown in the table below. Table 1 sample Fabric UPF value UPF value of fabric after 20 washes Example 1 97.6 120.86 Comparative Example 1 41.12 29.45 Comparative Example 2 32.97 30.12 control group 9.2 As can be seen from the table, the UV resistance of the example is greatly improved compared with the control group, and the UPF value of the fabric does not decrease after 20 washes. The comparison between Example 1 and Control Example 1 shows that the tannic acid film-forming treatment can significantly improve the UV resistance and wash resistance. The comparison between Control Example 1 and Control Example 2 shows that adding tannic acid to the preparation of nano zinc oxide finishing solution can improve the UV resistance of the finished fabric.

[0015] The above description provides examples of the preferred embodiments of the present invention, and any parts not described in detail are common knowledge to those skilled in the art. The scope of protection of the present invention is defined by the claims.

Claims

1. A method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing, characterized in that, Includes the following steps: Step 1: Tannic acid-assisted in-situ generation and finishing of nano zinc oxide: Prepare zinc chloride solution, and add tannic acid solution and sodium hydroxide solution dropwise in sequence to obtain tannic acid-zinc hydroxide composite finishing solution. Put the fabric into the finishing solution for finishing, take it out and dry it. Step 2, post-treatment after tannic acid film formation: Immerse the fabric treated in Step 1 in tannic acid solution for a period of time, then remove and dry it.

2. The method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing according to claim 1, characterized in that, In step 1, the concentration of zinc chloride solution is 1-40 g / L, the concentration of tannic acid solution is 1-35 g / L, the concentration of sodium hydroxide is 1-40 g / L, and the molar ratio of zinc chloride, sodium hydroxide and tannic acid added is 50:100:(1-4).

3. The method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing according to claim 1, characterized in that, In step 1, the finishing temperature is 60-100℃ and the finishing time is 5-120min.

4. The method for preparing durable UV-resistant fabrics using a tannic acid / nano zinc oxide composite functional finishing according to claim 1, characterized in that, In step 2, the concentration of tannic acid solution is 1-10 g / L, the soaking time is 12-60 h, and the pH value is 7.5-11.