Ultraviolet curing super-hydrophobic cotton fabric for oil-water separation and preparation method of ultraviolet curing super-hydrophobic cotton fabric

Abstract

The invention discloses a preparation method of an ultraviolet curing super-hydrophobic cotton fabric for oil-water separation. The preparation method specifically comprises the following steps: step 1, preparing ultraviolet curing resin based on cardanol; step 2, preparing silicon dioxide modified by gamma-methacryloxy propyl trimethoxy silane; and step 3, preparing the ultraviolet curing super-hydrophobic cotton fabric for oil-water separation according to products obtained in the step 1 and the step 2. The invention further discloses the ultraviolet curing super-hydrophobic cotton fabric for oil-water separation. The problems that an existing oil-water separation material is poor in stability and low in oil-water separation efficiency are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and relates to an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation. The present invention also relates to a preparation method of an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation. Background Art

[0002] At present, superhydrophobic materials with high separation efficiency and reusability have attracted much attention in the field of oil-water separation due to their selective oil absorption and oil removal properties. In past research, various materials such as textiles, metal meshes, porous sponges, and polymer films have been used as substrates for the preparation of superhydrophobic surfaces in the field of oil-water separation. In contrast, textiles have significant advantages such as ecological environmental protection, low cost, good stability, and strong absorption ability, and are considered to be one of the ideal oil-water separation materials.

[0003] Although a large number of studies have been conducted on constructing superhydrophobic coatings on the fabric surface, the existing preparation methods have relatively cumbersome manufacturing processes, and the prepared hydrophobic materials have poor stability and low oil-water separation efficiency. Therefore, it is still an urgent problem to be solved at present to prepare an oil-water separation cotton fabric with high separation efficiency and good stability. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation, which solves the problems of poor stability and low oil-water separation efficiency existing in the existing oil-water separation materials.

[0005] Another purpose of the present invention is to provide an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation.

[0006] The first technical solution adopted by the present invention is a preparation method of an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation, which specifically includes the following steps: Step 1, prepare a cashew phenol-based ultraviolet-curable resin; Step 2, prepare γ-methacryloxypropyltrimethoxysilane-modified silica; Step 3, prepare an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation according to the products obtained in Step 1 and Step 2.

[0007] The characteristics of the first technical solution of the present invention also lie in: The specific process of Step 1 is: Add 4,4'-diisocyanatodicyclohexylmethane, cardanol, pentaerythritol triacrylate, and ethyl acetate with a molar ratio of 1:2:1:1 to 1:2.02:1:1 into a three-necked round-bottom flask in sequence. Under a nitrogen atmosphere, stir the reaction mixture and heat it to 75 °C - 85 °C for insulation for 1 h - 3 h, then stop the reaction. Rotate and evaporate for 5 min - 10 min at 30 °C - 40 °C to remove the unreacted solvent, and obtain cardanol-based ultraviolet curable resin.

[0008] In step 1, the stirring rate under a nitrogen atmosphere is 400 rpm - 600 rpm.

[0009] In step 1, the structural formula of the cardanol-based ultraviolet curable resin is: 。

[0010] The specific process of step 2 is as follows: Disperse 1 g - 3 g of silica in 30 mL - 90 mL of ethyl acetate, and dropwise add 3 g - 9 g of 3-(methacryloyloxy)propyltrimethoxysilane. Mix uniformly by ultrasonic vibration for 30 min, and dropwise add ammonia water until the pH value of the solution is 10; subsequently, magnetically stir the mixture at 80 °C - 90 °C for 8 h - 12 h. Wash the obtained product repeatedly with absolute ethanol to remove the unreacted 3-(methacryloyloxy)propyltrimethoxysilane, centrifuge to separate the product, and vacuum dry it at 80 °C for 10 hours to obtain a white powder, denoted as mSiO 2 。

[0011] In step 2, the centrifugation time is 10 min - 30 min.

[0012] The specific process of step 3 is as follows: Step 3.1, cut the cotton fabric woven from cotton fibers into a size of 5 cm × 5 cm, and then soak it in a 10% - 20% (mass fraction) NaOH solution for 30 min - 50 min under the action of ultrasonic waves to remove pollutants; Step 3.2, weigh 1 g - 2 g of the product obtained in step 1, 1 g - 2 g of the product obtained in step 2, 1 g - 2 g of polydimethylsiloxane, and 0.1 g - 0.2 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, add them into 50 g - 60 g of n-hexane, and stir at room temperature for 1 h - 2 h to mix evenly to obtain a mixed solution; Step 3.3, at room temperature, immerse the pure cotton fabric washed in step 3.1 into the mixed solution prepared in step 3.2 for 10 min - 30 min, then take out the fabric and irradiate it under an ultraviolet lamp for 20 s - 30 s to obtain a superhydrophobic cotton fabric.

[0013] The second technical solution adopted by the present invention is that the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation is prepared by using the above-mentioned preparation method of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation.

[0014] The beneficial effects of the present invention are as follows: (1) Based on the ultraviolet-curing technology, the cotton fabric prepared by the simple dip-coating method has excellent superhydrophobicity and certain wear resistance, providing a reference for the research on the superhydrophobic properties of fabrics and showing promise for application in the field of superhydrophobic cotton fabrics for oil-water separation.

[0015] (2) PDMS gives the coating an extremely low surface energy, increasing the hydrophobicity of the coating; nano-silica increases the roughness of the coating, and the synergistic effect between the two endows the coating with excellent superhydrophobic properties and hardness.

[0016] (3) The prepared superhydrophobic cotton fabric has a contact angle of 151°, and has good separation efficiency under various oil-water mixtures. It still maintains good hydrophobicity after 100 friction cycles and has excellent wear resistance.

[0017] (4) The prepared superhydrophobic cotton fabric still has superhydrophobicity after being immersed in different pH solutions for 24 hours, indicating the potential of the superhydrophobic cotton fabric for use in extreme environments. Description of the Drawings

[0018] Figure 1 It is the oil-water separation efficiency diagram of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation of the present invention; Figure 2 It is the water contact angle diagram of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation of the present invention; Figure 3 It is the contact angle diagram after friction cycle of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation of the present invention.

[0019] Figure 4 It is the comparison diagram of the water contact angles of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the ultraviolet-cured superhydrophobic cotton fabric for oil-water separation of the present invention after being immersed in solutions with different pH values (pH = 1, 3, 5, 7, 9, 11, 13) for 24 h. Detailed Embodiments

[0020] The present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0021] The preparation method of the ultraviolet-curable superhydrophobic cotton fabric for oil-water separation of the present invention specifically includes the following steps: Step 1, prepare an ultraviolet-curable resin based on cardanol. The specific process of Step 1 is as follows: Add 4,4'-diisocyanatodicyclohexylmethane, cardanol, pentaerythritol triacrylate and ethyl acetate with a molar ratio of 1:2:1:1 to 1:2.02:1:1 into a three-necked round-bottom flask in sequence. Under a nitrogen atmosphere, stir the reaction mixture at a rotation speed of 400 rpm to 600 rpm and heat it to 75°C to 85°C for insulation for 1 h to 3 h, then stop the reaction. Rotate and evaporate for 5 min to 10 min at 30°C to 40°C to remove the unreacted solvent, and obtain a cardanol-based ultraviolet-curable resin. The structural formula of the cardanol-based ultraviolet-curable resin is: 。

[0022] Step 2, prepare silica modified by γ-methacryloxypropyltrimethoxysilane. The specific process of Step 2 is as follows: Disperse 1 g to 3 g of silica in 30 mL to 90 mL of ethyl acetate, and dropwise add 3 g to 9 g of 3-(methacryloxy)propyltrimethoxysilane. Mix uniformly by ultrasonic vibration for 30 min, and dropwise add ammonia water until the pH value of the solution is 10; then, magnetically stir the mixture at 80°C to 90°C for 8 h to 12 h. The obtained product is repeatedly washed with absolute ethanol to remove the unreacted 3-(methacryloxy)propyltrimethoxysilane, centrifuged for 10 min to 30 min to separate the product, and vacuum dried at 80°C for 10 hours to obtain a white powder, denoted as mSiO 2 (modified silica, m represents modification).

[0023] Step 3, prepare an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation according to the products obtained in Step 1 and Step 2; the specific process of Step 3 is as follows: Step 3.1, cut the cotton fabric woven from cotton fibers into a size of 5 cm × 5 cm, and then soak it in a 10% to 20% NaOH solution by mass fraction for 30 min to 50 min under the action of ultrasonic waves to remove pollutants; Step 3.2, weigh 1 g to 2 g of the product obtained in Step 1, 1 g to 2 g of the product obtained in Step 2, 1 g to 2 g of polydimethylsiloxane (PDMS) and 0.1 g to 0.2 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, add them to 50 g to 60 g of n-hexane, and stir at room temperature for 1 h to 2 h to mix evenly to obtain a mixed solution; Step 3.3, at room temperature, immerse the cotton fabric washed in Step 3.1 into the mixed solution prepared in Step 3.2 for 10 min to 30 min, then take out the fabric and irradiate it under ultraviolet light for 20 s to 30 s to obtain (silica / polydimethylsiloxane) superhydrophobic cotton fabric.

[0024] Example 1 The preparation method of the ultraviolet-curable superhydrophobic cotton fabric for oil-water separation of the present invention includes the following steps: Step 1, prepare a cashew phenol-based ultraviolet-curable resin; the specific process of Step 1 is: Add 4,4'-diisocyanatodicyclohexylmethane, cashew phenol, pentaerythritol triacrylate and ethyl acetate with a molar ratio of 1:2:1:1 into a three-necked round-bottom flask in sequence. In a nitrogen atmosphere, stir the reaction mixture at 400 rpm and heat it to 75 °C for heat preservation for 1 h, then stop the reaction. Rotate and evaporate for 5 min at 30 °C to remove the unreacted solvent to obtain a cashew phenol-based ultraviolet-curable resin.

[0025] In Step 1, the structural formula of the ultraviolet-curable resin is:

[0026] Step 2, prepare silica modified with γ-methacryloxypropyltrimethoxysilane; the specific process of Step 2 is: Disperse 1 g of silica in 30 mL of ethyl acetate, and dropwise add 3 g of 3-(methacryloxy)propyltrimethoxysilane (MPS). The two are uniformly mixed by ultrasonic vibration for 30 min. Dropwise add ammonia water until the pH value of the solution is 10. Subsequently, magnetically stir the above mixture at 80 °C for 8 h. The obtained product is repeatedly washed with anhydrous ethanol to remove the unreacted MPS, centrifuged for 10 min to separate the product, and vacuum dried at 80 °C for 10 hours to obtain a white powder, denoted as mSiO 2 .

[0027] Step 3, prepare an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation according to the products obtained in Step 1 and Step 2; The specific process of Step 3 is: Cut the pure cotton fabric into pieces of 5 cm×5 cm, and then soak it in a 10% NaOH solution for 30 min under the action of ultrasonic waves to remove pollutants. Weigh 1 g of the product obtained in step 1, 1 g of the product obtained in step 2, 1 g of PDMS and 0.1 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, add them to 50 g of n-hexane, and stir at room temperature for 1 h to mix evenly. At room temperature, immerse the washed pure cotton fabric in the above-prepared mixed solution for 10 min, then take out the fabric and irradiate it under ultraviolet light for 20 s to obtain a UV-curable superhydrophobic cotton fabric for oil-water separation.

[0028] As Figure 1 shown, six oils, namely n-hexane, toluene, dichloromethane, chloroform, petroleum ether and tetrahydrofuran, were selected to test the oil-water separation efficiency and separation flux of the UV-curable superhydrophobic cotton fabric for oil-water separation prepared in Example 1. The tested UV-curable superhydrophobic cotton fabric for oil-water separation has good oil-water separation performance for all six oil-water mixtures, and the separation efficiency is above 99%. Due to the strong non-polarity of chloroform, the maximum permeation flux can reach 2389.86 L·m -2 ·h -1 .

[0029] Figure 2 Figure for the water contact angle of the UV-curable superhydrophobic cotton fabric for oil-water separation prepared in Example 1, showing that the UV-curable superhydrophobic cotton fabric for oil-water separation has good hydrophobicity.

[0030] Figure 3 Shows the changes in the rolling angle and sliding angle of the UV-curable superhydrophobic cotton fabric for oil-water separation prepared in Example 1 after 100 cycles. It can be seen that as the number of wear cycles increases, the rolling angle of the UV-curable superhydrophobic cotton fabric for oil-water separation decreases, and the sliding angle increases. When the number of wear cycles reaches 100, the sliding angle is greater than 10°, and the UV-curable superhydrophobic cotton fabric for oil-water separation still has high hydrophobic performance at this time. The experimental results show that the UV-curable superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the present invention has excellent friction resistance. The cardanol-based UV-curable resin on the substrate plays an important role in enhancing the interfacial bonding force and enhances the friction resistance of the coating.

[0031] Figure 4 Shows that the superhydrophobic cotton fabric prepared in Example 1 was immersed in solutions with different pH values (pH = 1, 3, 5, 7, 9, 11, 13) respectively. After soaking for 24 h, the superhydrophobic cotton fabric has good stability, and the water contact angle is still above 150°. The results show that the superhydrophobic cotton fabric has excellent chemical stability.

[0032] Example 2 The ultraviolet-curable superhydrophobic cotton fabric for oil-water separation and its preparation method of the present invention include the following steps: Step 1, prepare an ultraviolet-curable resin based on cardanol; The specific process of Step 1 is as follows: Add 4,4'-dicyclohexylmethane diisocyanate, cardanol, pentaerythritol triacrylate and ethyl acetate with a molar ratio of 1:2.01:1:1 into a three-necked round-bottom flask in sequence. Under a nitrogen atmosphere, stir the reaction mixture at 500 rpm and heat it to 80 °C for 2 h, then stop the reaction. Rotate and evaporate for 8 min at 35 °C to remove the unreacted solvent, and obtain a cardanol-based ultraviolet-curable resin.

[0033] In Step 1, the structural formula of the ultraviolet-curable resin is:

[0034] Step 2, prepare silica modified with γ-methacryloxypropyltrimethoxysilane; The specific process of Step 2 is as follows: Disperse 2 g of silica in 60 mL of ethyl acetate, and dropwise add 6 g of 3-(methacryloxy)propyltrimethoxysilane (MPS). The two are uniformly mixed by ultrasonic vibration for 30 min. Dropwise add ammonia water until the pH value of the solution is 10. Subsequently, magnetically stir the above mixture at 85 °C for 10 h. The obtained product is repeatedly washed with anhydrous ethanol to remove the unreacted MPS, centrifuged for 20 min to separate the product, and vacuum dried at 80 °C for 10 hours to obtain a white powder, denoted as mSiO 2 .

[0035] Step 3, prepare an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation according to the products obtained in Step 1 and Step 2; The specific process of Step 3 is as follows: Cut the cotton fabric into pieces of 5 cm×5 cm, and then soak it in 15% NaOH solution for 40 min under the action of ultrasonic waves to remove possible contaminants. Weigh 1.5 g of the product obtained in Step 1, 1.5 g of the product obtained in Step 2, 1.5 g of PDMS and 0.15 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone and add them to 55 g of n-hexane, stir at room temperature for 1.5 h to mix uniformly. At room temperature, immerse the washed pure cotton fabric in the above-prepared mixed solution for 20 min, then take out the fabric and irradiate it under an ultraviolet lamp for 20 s to obtain an ultraviolet-curable superhydrophobic cotton fabric for oil-water separation.

[0036] Example 3 The present invention relates to a UV-curable superhydrophobic cotton fabric for oil-water separation and its preparation method, comprising the following steps: Step 1, prepare a UV-curable resin based on cardanol. The specific process of Step 1 is as follows: Sequentially add 4,4'-diisocyanatodicyclohexylmethane, cardanol, pentaerythritol triacrylate, and ethyl acetate with a molar ratio of 1:2.02:1:1 into a three-necked round-bottom flask. Under a nitrogen atmosphere, stir the reaction mixture at 600 rpm and heat it to 85 °C for 3 h, then stop the reaction. Rotate and evaporate for 10 min at 40 °C to remove the unreacted solvent, obtaining a cardanol-based UV-curable resin.

[0037] In Step 1, the structural formula of the UV-curable resin is:

[0038] The specific process of Step 2 is as follows: Disperse 3 g of silica in 90 mL of ethyl acetate, and dropwise add 9 g of 3-(methacryloyloxy)propyltrimethoxysilane (MPS). The two are uniformly mixed by ultrasonic vibration for 30 min. Dropwise add ammonia water until the pH value of the solution is 10. Subsequently, magnetically stir the above mixture at 90 °C for 12 h. The obtained product is repeatedly washed with anhydrous ethanol to remove the unreacted MPS, centrifuged for 30 min to separate the product, and vacuum dried at 80 °C for 10 hours to obtain a white powder, denoted as mSiO 2 .

[0039] Step 3, prepare a UV-curable superhydrophobic cotton fabric for oil-water separation according to the products obtained in Step 1 and Step 2. The specific process of Step 3 is as follows: Cut the cotton fabric into pieces of 5 cm × 5 cm, and then soak it in 20% NaOH solution for 50 min under the action of ultrasonic waves to remove possible contaminants. Weigh 2 g of the product obtained in Step 1, 2 g of the product obtained in Step 2, 2 g of PDMS, and 0.2 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone and add them to 60 g of n-hexane. Stir at room temperature for 2 h to uniformly mix. At room temperature, immerse the cleaned pure cotton fabric into the above-prepared mixed solution for 30 min, then take out the fabric and irradiate it under an ultraviolet lamp for 20 s to obtain a superhydrophobic cotton fabric.

[0040] Example 4 Compared with Example 1, in Step 3.3, take out the fabric and irradiate it under an ultraviolet lamp for 25 s, and the other steps are the same as those in Example 1.

[0041] Example 5 Compared with Example 1, in step 3.3, the fabric was taken out and irradiated under ultraviolet light for 28 s, and the remaining steps were the same as those in Example 1.

[0042] Example 6 Compared with Example 1, in step 3.3, the fabric was taken out and irradiated under ultraviolet light for 30 s, and the remaining steps were the same as those in Example 1 The raw materials of the superhydrophobic cotton fabric prepared by the present invention are environmentally friendly, have good durability, simple processes, and are suitable for large-scale production. Moreover, it has high-efficiency oil-water separation ability, and the separation efficiency can reach more than 98%. A simple and environmentally friendly method was used to prepare the ultraviolet-cured superhydrophobic cotton fabric. The prepared ultraviolet-cured superhydrophobic cotton fabric can withstand 100 wear cycles without significant reduction in hydrophobicity. In addition, the superhydrophobic cotton fabric is very stable in strong acidic and alkaline solutions and has a high-efficiency oil-water separation effect on various oil-water mixtures. This simple synthesis technology has the advantage of scalable manufacturing of multifunctional fabrics and can be used for multifunctional oil-water separation.

Claims

1. A method for preparing a UV-cured super-hydrophobic cotton fabric for oil-water separation, characterized in that: The specific steps include: Step 1, preparing a UV-curable resin based on cardanol; Step 2, preparing γ-methacryloxypropyltrimethoxysilane-modified silica; Step 3, preparing ultraviolet light-cured super-hydrophobic cotton fabric for oil-water separation according to the products obtained in steps 1 and 2.

2. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 1, characterized in that: The specific process of step 1 is as follows: To a three-necked round-bottom flask, 4,4-diisocyanate dicyclohexylmethane, cardanol, pentaerythritol triacrylate and ethyl acetate in a molar ratio of 1:2:1:1 to 1:2.02:1:1 were added in sequence. In a nitrogen atmosphere, the reaction mixture was stirred and heated to 75°C to 85°C for 1 h to 3 h, then the reaction was stopped, and the unreacted solvent was removed by rotary evaporation at 30°C to 40°C for 5 min to 10 min to obtain a cardanol-based UV-curable resin.

3. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 2, characterized in that: In the step 1, the stirring rate in a nitrogen atmosphere is 400 rpm to 600 rpm.

4. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 2, characterized in that: In the step 1, the structural formula of the cardanol-based UV-curable resin is: 。 5. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 2, characterized in that: The specific process of step 2 is: 1 g to 3 g of silica is dispersed in 30 mL to 90 mL of ethyl acetate, and 3 g to 9 g of 3-(methacryloyloxy)propyltrimethoxysilane is added dropwise, and the mixture is evenly mixed by ultrasonic vibration for 30 min. Ammonia water is added dropwise until the pH value of the solution is 10. Subsequently, the mixture is magnetically stirred at 80°C to 90°C for 8 h to 12 h. The product is repeatedly washed with anhydrous ethanol to remove unreacted 3-(methacryloyloxy)propyltrimethoxysilane. The product is separated by centrifugation and vacuum dried at 80°C for 10 h to obtain a white powder, which is recorded as mSiO2.

6. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 5, characterized in that: In the step 2, the centrifugation time is 10 min to 30 min.

7. The method for preparing the ultraviolet-cured super-hydrophobic cotton fabric for oil-water separation according to claim 5, characterized in that: The specific process of step 3 is as follows: Step 3.1, the cotton fabric woven from the cotton fiber is cut into a size of 5 cm×5 cm, and then immersed in a 10% to 20% mass fraction NaOH solution for 30 min to 50 min under the action of ultrasound to remove pollutants; Step 3.2, weigh 1 g to 2 g of the product obtained in step 1, 1 g to 2 g of the product obtained in step 2, 1 g to 2 g of polydimethylsiloxane and 0.1 g to 0.2 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, add them to 50 g to 60 g of n-hexane, stir at room temperature for 1 h to 2 h to mix evenly, and obtain a mixed solution; Step 3.3, at room temperature, immerse the pure cotton fabric washed in step 3.1 in the mixed solution prepared in step 3.2 for 10 min to 30 min, then take out the fabric and irradiate it under ultraviolet light for 20 s to 30 s to obtain a superhydrophobic cotton fabric.

8. A UV-cured super-hydrophobic cotton fabric for oil-water separation, prepared by the method for preparing the UV-cured super-hydrophobic cotton fabric for oil-water separation according to any one of claims 1 to 7.

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