Super-hydrophobic ramie fabric and preparation method thereof

Abstract

The invention relates to a super-hydrophobic ramie fabric and a preparation method thereof. The fabric can be prepared by adopting the following method: firstly, pretreating a ramie fabric; secondly, the ramie fabric is subjected to biological enzyme treatment; thirdly, graphene oxide, epoxy chloropropane and the like are prepared into finishing liquid; finally, the ramie fabric reacts in the finishing liquid, and the super-hydrophobic ramie fabric is prepared. The surface of the prepared super-hydrophobic ramie fabric contains graphene, the apparent contact angle range of water drops on the ramie fabric ranges from 150 degrees to 153 degrees, and the super-hydrophobic ramie fabric shows good super-hydrophobicity; after 10 times of water washing, the hydrophobic property of the ramie fabric is still not obviously weakened.

Description

Technical Field

[0001] The present invention belongs to the technical field of fabric preparation, and particularly relates to a superhydrophobic ramie fabric and a preparation method thereof. Background Art

[0002] With the rapid development of the times and the huge increase in population, the speed of textile replacement is constantly accelerating. It has become an inevitable trend to carry out multifunctional finishing on textiles to increase their added value. In recent years, the method of bionic superhydrophobic finishing on the surface of textiles has received great attention. The hydrophobic finishing of fabrics plays a very important role in enhancing the added value of textiles and improving the self-cleaning and anti-pollution properties of fabrics.

[0003] Ramie fabric is a fabric made of ramie fiber, which has the characteristics of fast moisture absorption and dispersion, good luster, and crispness and breathability. However, since the ramie component in this kind of fabric is composed of hydrophilic cellulose fibers, it has good moisture absorption and hydrophilic properties, is very easy to be contaminated, and is easy to adsorb various liquids, which affects its wearing performance. Therefore, studying a hydrophobic finishing method for ramie fabric is an important topic for developing multifunctional fabrics today.

[0004] Literature research shows that the superhydrophobic performance of ramie fabrics has received extensive attention. For example, Chinese Patent Application No. 201811041874.6 discloses a superhydrophobic finishing method for ramie fabrics: after impregnating and rolling the ramie fabric with a cyclodextrin treatment solution, then impregnating and rolling the ramie fabric with a hydrophobic finishing solution to obtain a superhydrophobic ramie fabric.

[0005] In the past, compounds containing long fluorocarbon chains were mostly used as hydrophobic finishing agents to obtain ramie fabrics with low surface free energy. Although the compounds in the fluorine-containing system have good finishing effects after treatment, such finishing agents are expensive. At the same time, recent research has found that fluorine-containing chemicals are difficult to biodegrade and pose potential hazards to the environment and human health. Therefore, how to make environmentally friendly finishing agents achieve the finishing effects of compounds with long fluorocarbon chains is an important topic for developing superhydrophobic ramie fabrics today. Summary of the Invention

[0006] Aiming at the above drawbacks existing in the prior art, the purpose of the present invention is to provide a superhydrophobic ramie fabric and a preparation method thereof.

[0007] The purpose of the present invention is to provide a superhydrophobic ramie fabric, which has the characteristics of superhydrophobicity, antibacterial property, environmental protection, etc.; this fabric can be prepared by the following method: First, pretreat the ramie fabric; Second, perform bio-enzyme treatment on the ramie fabric; Third, prepare a finishing solution with graphene oxide and epichlorohydrin, etc.; Finally, react the ramie fabric in the finishing solution to obtain a superhydrophobic ramie fabric.

[0008] The object of the present invention is achieved by the following technical solutions:

[0009] A method for preparing a superhydrophobic ramie fabric, comprising the following steps:

[0010] (1) Pretreatment of the ramie fabric: Immerse the ramie fabric in an alkali solution, control the temperature at 80 - 90 °C, and the immersion time at 20 - 40 minutes; after immersion, wash with tap water and dry.

[0011] Preferably, the alkali solution is an aqueous sodium hydroxide solution with a mass fraction of 10 - 20%.

[0012] Preferably, the dosage ratio of the ramie fabric to the alkali solution is 1 g∶(200 - 400) mL.

[0013] (2) Bio - enzyme treatment of the ramie fabric: Under ultrasonic conditions, place the ramie fabric treated in step (1) in an aqueous solution containing lignin peroxidase and treat it at room temperature.

[0014] Preferably, the dosage of lignin peroxidase in the aqueous solution of lignin peroxidase is 0.1 - 0.2% (mass fraction), the ultrasonic power is 100 - 200 W, the ultrasonic treatment time is 10 - 20 min, and the solid - liquid ratio is 1 g∶(100 - 200) mL.

[0015] (3) Preparation of the finishing solution: Dilute graphene oxide with water to obtain an aqueous solution of graphene oxide; adjust the pH of the aqueous solution of graphene oxide with an aqueous NaOH solution, add epichlorohydrin, and stir evenly to obtain the finishing solution.

[0016] Preferably, the mass fraction of the aqueous solution of graphene oxide is 0.01 - 0.03%.

[0017] Preferably, the mass fraction of the aqueous NaOH solution is 10 - 20%.

[0018] Preferably, the pH of the aqueous solution of graphene oxide is 11 - 12.

[0019] Preferably, the dosage of epichlorohydrin is 0.02% - 0.04% of the mass fraction of the aqueous solution of graphene oxide.

[0020] (4) Superhydrophobic finishing: Immerse the ramie fabric treated in step (2) in the finishing solution prepared in step (3), control the temperature of the finishing solution, and carry out the reaction; after the reaction, wash the ramie fabric with water and dry to obtain the superhydrophobic ramie fabric.

[0021] Preferably, the dosage ratio of the ramie fabric to the finishing solution is 1 g∶(30 - 50) mL.

[0022] Preferably, the temperature of the finishing liquid is 50 to 60 °C.

[0023] Preferably, the reaction time is 1 to 3 minutes.

[0024] Analysis of the reaction mechanism of the present invention: The molecular structure of graphene oxide is shown as follows. It can be seen therefrom that it contains a relatively large number of hydroxyl groups. Ramie fabrics contain a relatively large amount of lignin and have a relatively high crystallinity of fibers, resulting in certain difficulties in the reaction. The inventors of the present application unexpectedly found that under ultrasonic conditions, lignin peroxidase can reduce the lignin content on the surface of ramie fabrics and improve the reaction efficiency, thereby facilitating the reaction of graphene oxide with ramie fibers under the condition of the cross-linking agent epichlorohydrin. Finally, graphene is grafted onto the surface of ramie fabrics, achieving an improvement in the hydrophobicity of ramie fabrics.

[0025]

[0026] The present invention has the following remarkable features:

[0027] (1) Graphene is a hydrophobic material, but it is very difficult to be applied to the surface of fabrics. The inventors of the present application unexpectedly found that after ramie fabrics are treated with lignin peroxidase, graphene oxide can be easily grafted onto the surface of ramie fabrics, and the hydrophobicity of the surface of ramie fabrics grafted with graphene is significantly enhanced.

[0028] (2) The inventors of the present application unexpectedly found that the treatment of ramie fabrics with lignin peroxidase is beneficial to the reaction efficiency with graphene oxide, that is, beneficial to the improvement of the hydrophobicity of ramie fabrics.

[0029] (3) The superhydrophobic ramie fabrics prepared by the present invention have graphene on the surface. The apparent contact angle of water droplets on the ramie fabrics ranges between 150° and 153°, showing good superhydrophobicity. After 10 washes, the hydrophobic performance of the ramie fabrics has not been significantly weakened.

[0030] (4) The superhydrophobic ramie fabrics prepared by the present invention have not been significantly weakened in superhydrophobic performance after 10 washes, indicating that graphene is firmly attached to the surface of ramie fabrics.

[0031] (5) The raw materials of the superhydrophobic ramie fabrics prepared by the present invention are widely sourced, and the preparation process is simple, having good market promotion prospects. Detailed Description of the Invention

[0032] The following examples and comparative examples illustrate the present invention in detail.

[0033] Example 1

[0034] In this example, a method for preparing superhydrophobic ramie fabrics, the preparation method comprising the following steps:

[0035] (1) Pretreatment of ramie fabric: Immerse 10 g of ramie fabric in 300 mL of sodium hydroxide aqueous solution with a mass fraction of 15%, control the temperature at 85 °C, and the immersion time is 30 minutes; after immersion, wash with tap water and dry.

[0036] (2) Bio-enzymatic treatment of ramie fabric: Under ultrasonic conditions, place the ramie fabric treated in step (1) in an aqueous solution containing 0.15% mass fraction of lignin peroxidase and treat it at room temperature. The material-liquid ratio is 1 g∶150 mL, the ultrasonic power is 150 W, and the ultrasonic treatment time is 15 min.

[0037] (3) Preparation of finishing solution: Dilute graphene oxide with water to obtain an aqueous solution of graphene oxide with a mass fraction of 0.02%; adjust the pH of the graphene oxide aqueous solution to 11.5 with a 15% NaOH aqueous solution, add epichlorohydrin accounting for 0.03% of the mass of the graphene oxide aqueous solution, and stir evenly to obtain the finishing solution.

[0038] (4) Superhydrophobic finishing: Immerse 10 g of the ramie fabric treated in step (2) in 400 mL of the finishing solution prepared in step (3), control the temperature of the finishing solution at 55 °C, and carry out the reaction for 2 minutes; after the reaction, wash the ramie fabric with water and dry to obtain the superhydrophobic ramie fabric.

[0039] Example 2

[0040] In this example, a method for preparing superhydrophobic ramie fabric, the preparation method includes the following steps:

[0041] (1) Pretreatment of ramie fabric: Immerse 10 g of ramie fabric in 200 mL of sodium hydroxide aqueous solution with a mass fraction of 10%, control the temperature at 80 °C, and the immersion time is 20 minutes; after immersion, wash with tap water and dry.

[0042] (2) Bio-enzymatic treatment of ramie fabric: Under ultrasonic conditions, place the ramie fabric treated in step (1) in an aqueous solution containing 0.1% mass fraction of lignin peroxidase and treat it at room temperature. The material-liquid ratio is 1 g∶100 mL, the ultrasonic power is 100 W, and the ultrasonic treatment time is 10 min.

[0043] (3) Preparation of finishing solution: Dilute graphene oxide with water to obtain an aqueous solution of graphene oxide with a mass fraction of 0.01%; adjust the pH of the graphene oxide aqueous solution to 11 with a 10% NaOH aqueous solution, add epichlorohydrin accounting for 0.02% of the mass of the graphene oxide aqueous solution, and stir evenly to obtain the finishing solution.

[0044] (4) Superhydrophobic finishing: Immerse 10 g of the ramie fabric treated in step (2) into 300 mL of the finishing solution prepared in step (3), adjust the temperature of the finishing solution to 50 °C, carry out the reaction, and the reaction time is 1 minute; after the reaction is completed, wash the ramie fabric with water and dry it to obtain the superhydrophobic ramie fabric.

[0045] Example 3

[0046] In this example, a method for preparing a superhydrophobic ramie fabric, the preparation method includes the following steps:

[0047] (1) Pretreatment of ramie fabric: Immerse 10 g of ramie fabric in 400 mL of sodium hydroxide aqueous solution with a mass fraction of 20%, control the temperature at 90 °C, and the immersion time is 40 minutes; after the immersion is completed, wash with tap water and dry.

[0048] (2) Bio-enzyme treatment of ramie fabric: Under ultrasonic conditions, place the ramie fabric treated in step (1) in an aqueous solution containing 0.2% lignin peroxidase at room temperature for treatment, the material-liquid ratio is 1 g∶200 mL, the ultrasonic power is 200 W, and the ultrasonic treatment time is 20 min.

[0049] (3) Preparation of finishing solution: Dilute graphene oxide with water to obtain an aqueous solution of graphene oxide with a mass fraction of 0.03%; adjust the pH of the graphene oxide aqueous solution to 12 with a 20% NaOH aqueous solution, add epichlorohydrin accounting for 0.04% of the mass fraction of the graphene oxide aqueous solution, and stir evenly to obtain the finishing solution.

[0050] (4) Superhydrophobic finishing: Immerse 10 g of the ramie fabric treated in step (2) into 500 mL of the finishing solution prepared in step (3), adjust the temperature of the finishing solution to 60 °C, carry out the reaction, and the reaction time is 3 minutes; after the reaction is completed, wash the ramie fabric with water and dry it to obtain the superhydrophobic ramie fabric.

[0051] Comparative Example A

[0052] Taking Example 1 as a comparison, in this comparative example, the ramie fabric is not pretreated, that is: step (1) is not implemented, and other preparation methods are implemented according to the preparation method of Example 1.

[0053] Comparative Example B

[0054] Taking Example 1 as a comparison, in this comparative example, ultrasonic waves are not implemented, that is: delete "Under ultrasonic conditions," and "the ultrasonic power is 150 W, and the ultrasonic treatment time is 15 min" in step (2), and other preparation methods are implemented according to the preparation method of Example 1.

[0055] Comparative Example C

[0056] Taking Example 1 as a comparison, in this comparative example, the pH of the finishing solution was changed, that is: in step (3), "adjusting the pH of the graphene oxide aqueous solution to 11.5" was changed to "adjusting the pH of the graphene oxide aqueous solution to 7.5", and other preparation methods were implemented according to the preparation method of Example 1.

[0057] Superhydrophobic performance test:

[0058] In order to better detect the superhydrophobicity of the superhydrophobic ramie fabric prepared in the present invention, the superhydrophobic ramie fabrics a, b, c, d, e, and f prepared in the above specific Examples 1 to 3 and Comparative Examples A to C of the present invention were selected. An XG-CAMA1 basic contact angle tester was used to measure the apparent contact angle of water droplets on the surface of the superhydrophobic ramie fabric. The number of test specimens was not less than 30, and the test average value was taken. The fabrics to be tested were subjected to standard washing according to the washing method of the color fastness to washing tester GB / T 20944.1-2007, and the superhydrophobic performance of the initial samples and the samples after 10 washes was tested. The test results are shown in Table 1.

[0059] Table 1 Apparent contact angles of water droplets on the ramie fabrics a, b, c, d, e, f prepared in Examples 1 to 3 and Comparative Examples A to C

[0060] Apparent contact angle (°) a b c d e f Unwashed 152.3 151.2 150.7 101.7 90.1 82.0 Washed 10 times 144.3 142.4 144.6 67.5 65.4 56.8

[0061] As can be seen from Table 1, when the ramie fabric was not washed, the apparent contact angles of water droplets on the ramie fabrics a, b, c prepared in Examples 1 to 3 were in the range of 150° to 153°. After 10 washes, the hydrophobic properties of fabrics a, b, c did not decrease significantly. Therefore, it can be considered that the ramie fabric prepared in the present invention has superhydrophobicity. The superhydrophobicity of the superhydrophobic ramie fabrics d, e, f prepared in Comparative Examples A-C was significantly worse, indicating that the pretreatment of the ramie fabric, the implementation of ultrasonic waves, and the pH of the finishing solution all have important effects on the superhydrophobic performance of the ramie fabric.

Claims

1. Preparation method of superhydrophobic ramie fabric, characterized in that, The preparation method comprises the following steps: (1) Pretreatment of ramie fabric: Immerse the ramie fabric in an alkali solution with the temperature controlled at 80 - 90 °C and the immersion time of 20 - 40 minutes; after immersion, wash with tap water and dry. (2) Bio-enzyme treatment of ramie fabric: Under ultrasonic conditions, place the ramie fabric treated in step (1) in an aqueous solution containing lignin peroxidase and treat it at room temperature. (3) Preparation of finishing solution: Dilute graphene oxide with water to obtain an aqueous solution of graphene oxide; adjust the pH of the aqueous solution of graphene oxide with an aqueous NaOH solution, add epichlorohydrin, and stir evenly to obtain the finishing solution. (4) Superhydrophobic finishing: Immerse the ramie fabric treated in step (2) into the finishing solution prepared in step (3), adjust the temperature of the finishing solution, and carry out the reaction; after the reaction, wash and dry the ramie fabric to obtain the superhydrophobic ramie fabric.

2. The preparation method of the superhydrophobic ramie fabric according to claim 1, wherein, In step (1), the alkali solution is a 10 - 20 wt% aqueous sodium hydroxide solution; the dosage ratio of the ramie fabric to the alkali solution is 1 g:(200 - 400) mL.

3. The preparation method of the superhydrophobic ramie fabric according to claim 1, wherein, In step (2), the dosage of lignin peroxidase in the aqueous solution of lignin peroxidase is 0.1 - 0.2 wt%, the ultrasonic power is 100 - 200 W, the ultrasonic treatment time is 10 - 20 min, and the solid-liquid ratio is 1 g:(100 - 200) mL.

4. The preparation method of the superhydrophobic ramie fabric according to claim 1, wherein In step (3), the concentration of the aqueous solution of graphene oxide is 0.01 - 0.03 wt%; the concentration of the aqueous NaOH solution is 10 - 20 wt%; the pH of the aqueous solution of graphene oxide is 11 - 12; the dosage of epichlorohydrin accounts for 0.02% - 0.04 wt% of the concentration of the aqueous solution of graphene oxide.

5. The preparation method of the superhydrophobic ramie fabric according to claim 1, characterized in that, In step (4), the dosage ratio of the ramie fabric to the finishing solution is 1 g:(30 - 50) mL; the temperature of the finishing solution is 50 - 60 °C; the reaction time is 1 - 3 minutes.

6. Superhydrophobic ramie fabric, characterized in that, Prepared by the method according to any one of claims 1 - 5.

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