Ultraviolet light-cured superhydrophobic cotton fabric for oil-water separation and method of making the same

Abstract

The application discloses a preparation method of ultraviolet light cured super-hydrophobic cotton fabric for oil-water separation, and specifically comprises the following steps: step 1, preparing a cardanol-based ultraviolet light cured resin; step 2, preparing gamma-methacryloxypropyltrimethoxysilane modified silica; and step 3, preparing the ultraviolet light cured super-hydrophobic cotton fabric for oil-water separation according to the products obtained in steps 1 and 2. The application further discloses the ultraviolet light cured super-hydrophobic cotton fabric for oil-water separation. The application solves the problems of poor stability and low oil-water separation efficiency of the existing oil-water separation materials.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and relates to UV-curable superhydrophobic cotton fabric for oil-water separation. This invention also relates to a method for preparing UV-curable superhydrophobic cotton fabric for oil-water separation. Background Technology

[0002] Currently, superhydrophobic materials with high separation efficiency and reusability are attracting significant attention in the field of oil-water separation due to their selective oil absorption and removal properties. In past research, various materials such as textiles, metal meshes, porous sponges, and polymer films have been used as substrates for superhydrophobic surface preparation in oil-water separation. In comparison, textiles possess significant advantages such as environmental friendliness, low cost, good stability, and strong absorption capacity, and are considered one of the ideal materials for oil-water separation.

[0003] Although numerous studies have explored the creation of superhydrophobic coatings on fabric surfaces, existing methods are cumbersome, and the resulting hydrophobic materials exhibit poor stability and low oil-water separation efficiency. Therefore, developing oil-water separation cotton fabrics with high separation efficiency and good stability remains a pressing issue. Summary of the Invention

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

[0005] Another object of the present invention is to provide a UV-curable superhydrophobic cotton fabric for oil-water separation.

[0006] The first technical solution adopted in this invention is a method for preparing ultraviolet-cured superhydrophobic cotton fabric for oil-water separation, which specifically includes the following steps:

[0007] Step 1: Prepare a UV-curable resin based on cashew phenol;

[0008] Step 2: Prepare γ-methacryloyloxypropyltrimethoxysilane-modified silica;

[0009] Step 3: Prepare UV-cured superhydrophobic cotton fabric for oil-water separation based on the products obtained in Step 1 and Step 2.

[0010] The first technical solution of this invention is further characterized by:

[0011] The specific process of step 1 is as follows:

[0012] 4,4-diisocyanate dicyclohexylmethane, cashew nut shell phenol, pentaerythritol triacrylate, and ethyl acetate were added sequentially to a three-necked round-bottom flask in a molar ratio of 1:2:1:1 to 1:2.02:1:1. Under a nitrogen atmosphere, the reaction mixture was stirred and heated to 75℃~85℃ for 1 h~3 h. The reaction was then stopped, and the unreacted solvent was removed by rotary evaporation at 30℃~40℃ for 5 min~10 min to obtain cashew nut shell phenol-based UV-curable resin.

[0013] In step 1, the stirring speed in the nitrogen atmosphere is 400 rpm to 600 rpm.

[0014] In step 1, the structural formula of the cashew phenol-based UV-curable resin is:

[0015] .

[0016] The specific process of step 2 is as follows:

[0017] 1 g to 3 g of silica was dispersed in 30 mL to 90 mL of ethyl acetate, and 3 g to 9 g of 3-(methacryloyloxy)propyltrimethoxysilane was added dropwise. The mixture was vibrated ultrasonically for 30 min to mix evenly. Ammonia was added dropwise until the pH of the solution was 10. Then, the mixture was magnetically stirred at 80 °C to 90 °C for 8 h to 12 h. The product was repeatedly washed with anhydrous ethanol to remove unreacted 3-(methacryloyloxy)propyltrimethoxysilane. The product was separated by centrifugation and vacuum dried at 80 °C for 10 h to obtain a white powder, denoted as mSiO2.

[0018] In step 2, the centrifugation time is 10 min to 30 min.

[0019] The specific process of step 3 is as follows:

[0020] Step 3.1: Cut the cotton fabric spun from cotton fibers into 5 cm × 5 cm pieces, and then soak them in a 10%–20% NaOH solution for 30–50 min under ultrasonic treatment to remove contaminants.

[0021] 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 and add them to 50 g to 60 g of n-hexane. Stir at room temperature for 1 h to 2 h to mix evenly to obtain a mixed solution.

[0022] 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 to 30 min, then take out the fabric and irradiate it under a UV lamp for 20 s to 30 s to obtain superhydrophobic cotton fabric.

[0023] The second technical solution adopted in this invention is an ultraviolet-cured superhydrophobic cotton fabric for oil-water separation, which is prepared by the above-mentioned method for preparing ultraviolet-cured superhydrophobic cotton fabric for oil-water separation.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) Based on 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 study of superhydrophobic properties of fabrics, and is expected to be applied in the field of oil-water separation superhydrophobic cotton fabrics.

[0026] (2) PDMS gives the coating 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 gives the coating excellent superhydrophobic properties and hardness.

[0027] (3) The prepared superhydrophobic cotton fabric has a contact angle of 151° and good separation efficiency under various oil-water mixtures. It still maintains good hydrophobicity after 100 friction cycles and has excellent wear resistance.

[0028] (4) The superhydrophobic cotton fabric prepared still has superhydrophobicity after being soaked in different pH solutions for 24 hours, indicating that the superhydrophobic cotton fabric has the potential to be used in extreme environments. Attached Figure Description

[0029] Figure 1 This is a graph showing the oil-water separation efficiency of the UV-cured superhydrophobic cotton fabric prepared in Example 1 of the preparation method of the UV-cured superhydrophobic cotton fabric for oil-water separation according to the present invention.

[0030] Figure 2 This is a water contact angle diagram of the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the UV-cured superhydrophobic cotton fabric for oil-water separation of the present invention.

[0031] Figure 3 This is a contact angle diagram of the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the UV-cured superhydrophobic cotton fabric for oil-water separation of the present invention after friction cycle.

[0032] Figure 4This is a comparison of the water contact angles of the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of the preparation method of the UV-cured superhydrophobic cotton fabric for oil-water separation in this invention after being immersed in solutions of different pH values ​​(pH=1, 3, 5, 7, 9, 11, 13) for 24 h. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] The present invention relates to a method for preparing UV-cured superhydrophobic cotton fabric for oil-water separation, which specifically includes the following steps:

[0035] Step 1: Prepare a UV-curable resin based on cashew phenol;

[0036] The specific process of step 1 is as follows:

[0037] 4,4-diisocyanate dicyclohexylmethane, cashew nut shell phenol, pentaerythritol triacrylate, and ethyl acetate were added sequentially to a three-necked round-bottom flask in a molar ratio of 1:2:1:1 to 1:2.02:1:1. Under a nitrogen atmosphere, the reaction mixture was stirred at 400 rpm to 600 rpm and heated to 75°C to 85°C for 1 h to 3 h. The reaction was then stopped, and unreacted solvent was removed by rotary evaporation at 30°C to 40°C for 5 min to 10 min, yielding a cashew nut shell phenol-based UV-curable resin. The structural formula of the cashew nut shell phenol-based UV-curable resin is as follows:

[0038] .

[0039] Step 2: Prepare γ-methacryloyloxypropyltrimethoxysilane-modified silica;

[0040] The specific process of step 2 is as follows:

[0041] 1 g to 3 g of silica was dispersed in 30 mL to 90 mL of ethyl acetate, and 3 g to 9 g of 3-(methacryloyloxy)propyltrimethoxysilane was added dropwise. The mixture was ultrasonically vibrated for 30 min to mix evenly. Ammonia was added dropwise until the pH of the solution was 10. Subsequently, the mixture was magnetically stirred at 80 °C to 90 °C for 8 h to 12 h. The product was repeatedly washed with anhydrous ethanol to remove unreacted 3-(methacryloyloxy)propyltrimethoxysilane. The product was separated by centrifugation for 10 min to 30 min and then vacuum dried at 80 °C for 10 h to obtain a white powder, denoted as mSiO2 (modified silica, where m represents modification).

[0042] Step 3: Prepare UV-cured superhydrophobic cotton fabric for oil-water separation based on the products obtained in Steps 1 and 2; the specific process of Step 3 is as follows:

[0043] Step 3.1: Cut the cotton fabric spun from cotton fibers into 5 cm × 5 cm pieces, and then soak them in a 10%–20% NaOH solution for 30–50 min under ultrasonic treatment to remove contaminants.

[0044] 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 and add them to 50 g to 60 g of n-hexane. Stir at room temperature for 1 h to 2 h to mix evenly to obtain a mixed solution.

[0045] 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 to 30 min, then take out the fabric and irradiate it under a UV lamp for 20 s to 30 s to obtain (silica / polydimethylsiloxane) superhydrophobic cotton fabric.

[0046] Example 1

[0047] The present invention relates to a method for preparing UV-cured superhydrophobic cotton fabric for oil-water separation, comprising the following steps:

[0048] Step 1: Preparation of UV-curable resin based on cashew nut shell phenol; the specific process of Step 1 is as follows:

[0049] 4,4-diisocyanate dicyclohexylmethane, cashew nut shell phenol, pentaerythritol triacrylate, and ethyl acetate were added sequentially to a three-necked round-bottom flask in a molar ratio of 1:2:1:1. The reaction mixture was stirred at 400 rpm under a nitrogen atmosphere and heated to 75°C for 1 h. The reaction was then stopped, and the unreacted solvent was removed by rotary evaporation at 30°C for 5 min to obtain cashew nut shell phenol-based UV-curable resin.

[0050] In step 1, the structural formula of the UV-curable resin is:

[0051]

[0052] Step 2, prepare γ-methacryloyloxypropyltrimethoxysilane modified silica; the specific process of step 2 is as follows:

[0053] 1 g of silica was dispersed in 30 mL of ethyl acetate, and 3 g of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) was added dropwise. The two were mixed uniformly by ultrasonic vibration for 30 min. Ammonia was added dropwise until the pH of the solution reached 10. Subsequently, the mixture was magnetically stirred at 80 °C for 8 h. The resulting product was repeatedly washed with anhydrous ethanol to remove unreacted MPS, centrifuged for 10 min to separate the product, and then vacuum dried at 80 °C for 10 h to obtain a white powder, denoted as mSiO2.

[0054] Step 3: Prepare UV-cured superhydrophobic cotton fabric for oil-water separation based on the products obtained in Step 1 and Step 2.

[0055] The specific process of step 3 is as follows:

[0056] Pure cotton fabric was cut into 5 cm × 5 cm pieces and then soaked in a 10% NaOH solution for 30 min under ultrasonic treatment to remove contaminants. 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 were weighed and added to 50 g of n-hexane, and stirred at room temperature for 1 h to achieve uniform mixing. At room temperature, the washed pure cotton fabric was immersed in the prepared mixed solution for 10 min, then removed and irradiated under a UV lamp for 20 s to obtain a UV-cured superhydrophobic cotton fabric for oil-water separation.

[0057] like Figure 1 As shown, six oils—n-hexane, toluene, dichloromethane, chloroform, petroleum ether, and tetrahydrofuran—were selected to test the oil-water separation efficiency and separation flux of the UV-cured superhydrophobic cotton fabric prepared in Example 1 for oil-water separation. The tested UV-cured superhydrophobic cotton fabric for oil-water separation exhibited good oil-water separation performance for all six oil-water mixtures, with separation efficiencies exceeding 99%. Due to the strong nonpolarity of chloroform, the maximum permeation flux reached 2389.86 L·m⁻¹. -2 ·h -1 .

[0058] Figure 2 The water contact angle diagram of the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 shows that the UV-cured superhydrophobic cotton fabric for oil-water separation has good hydrophobicity.

[0059] Figure 3The changes in the roll-off angle and sliding angle of the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 after 100 wear cycles are shown. It can be seen that with the increase of wear cycles, the roll-off angle of the UV-cured superhydrophobic cotton fabric for oil-water separation decreases while the sliding angle increases. After 100 wear cycles, the sliding angle is greater than 10°, indicating that the UV-cured superhydrophobic cotton fabric for oil-water separation still maintains high hydrophobicity. Experimental results show that the UV-cured superhydrophobic cotton fabric for oil-water separation prepared in Example 1 of this invention has excellent abrasion resistance. The cashew phenol-based UV-cured resin on the matrix plays an important role in enhancing the interfacial adhesion and improving the abrasion resistance of the coating.

[0060] Figure 4 The results show that the superhydrophobic cotton fabric prepared in Example 1, after being immersed in solutions of different pH values ​​(pH=1, 3, 5, 7, 9, 11, 13) for 24 h, exhibits good stability, with the water contact angle remaining above 150°. These results demonstrate the excellent chemical stability of the superhydrophobic cotton fabric.

[0061] Example 2

[0062] This invention relates to a UV-curable superhydrophobic cotton fabric for oil-water separation and its preparation method, comprising the following steps:

[0063] Step 1: Prepare a UV-curable resin based on cashew phenol;

[0064] The specific process of step 1 is as follows:

[0065] 4,4-diisocyanate dicyclohexylmethane, cashew nut shell phenol, pentaerythritol triacrylate, and ethyl acetate were added sequentially to a three-necked round-bottom flask in a molar ratio of 1:2.01:1:1. The reaction mixture was stirred at 500 rpm under a nitrogen atmosphere and heated to 80°C for 2 h. The reaction was then stopped, and the unreacted solvent was removed by rotary evaporation at 35°C for 8 min to obtain cashew nut shell phenol-based UV-curable resin.

[0066] In step 1, the structural formula of the UV-curable resin is:

[0067]

[0068] Step 2: Prepare γ-methacryloyloxypropyltrimethoxysilane-modified silica;

[0069] The specific process of step 2 is as follows:

[0070] 2 g of silica was dispersed in 60 mL of ethyl acetate, and 6 g of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) was added dropwise. The two were mixed uniformly by ultrasonic vibration for 30 min. Ammonia was added dropwise until the pH of the solution reached 10. Subsequently, the mixture was magnetically stirred at 85 °C for 10 h. The resulting product was repeatedly washed with anhydrous ethanol to remove unreacted MPS, centrifuged for 20 min to separate the product, and then vacuum dried at 80 °C for 10 h to obtain a white powder, denoted as mSiO2.

[0071] Step 3: Prepare UV-cured superhydrophobic cotton fabric for oil-water separation based on the products obtained in Step 1 and Step 2.

[0072] The specific process of step 3 is as follows:

[0073] Cotton fabric was cut into 5 cm × 5 cm pieces and then soaked in 15% NaOH solution for 40 min under ultrasonic treatment to remove possible contaminants. 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 were weighed and added to 55 g of n-hexane, and stirred at room temperature for 1.5 h to achieve uniform mixing. The washed pure cotton fabric was then immersed in the prepared mixed solution at room temperature for 20 min, and then removed and irradiated under a UV lamp for 20 s to obtain a UV-cured superhydrophobic cotton fabric for oil-water separation.

[0074] Example 3

[0075] This invention relates to a UV-curable superhydrophobic cotton fabric for oil-water separation and its preparation method, comprising the following steps:

[0076] Step 1: Prepare a UV-curable resin based on cashew phenol;

[0077] The specific process of step 1 is as follows:

[0078] 4,4-diisocyanate dicyclohexylmethane, cashew nut shell phenol, pentaerythritol triacrylate, and ethyl acetate were added sequentially to a three-necked round-bottom flask in a molar ratio of 1:2.02:1:1. The reaction mixture was stirred at 600 rpm under a nitrogen atmosphere and heated to 85°C for 3 h. The reaction was then stopped, and the unreacted solvent was removed by rotary evaporation at 40°C for 10 min to obtain cashew nut shell phenol-based UV-curable resin.

[0079] In step 1, the structural formula of the UV-curable resin is:

[0080]

[0081] The specific process of step 2 is as follows:

[0082] 3 g of silica was dispersed in 90 mL of ethyl acetate, and 9 g of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) was added dropwise. The two were mixed uniformly by ultrasonic vibration for 30 min. Ammonia was added dropwise until the pH of the solution reached 10. Subsequently, the mixture was magnetically stirred at 90 °C for 12 h. The resulting product was repeatedly washed with anhydrous ethanol to remove unreacted MPS, centrifuged for 30 min to separate the product, and then vacuum dried at 80 °C for 10 h to obtain a white powder, denoted as mSiO2.

[0083] Step 3: Prepare UV-cured superhydrophobic cotton fabric for oil-water separation based on the products obtained in Steps 1 and 2; the specific process of Step 3 is as follows:

[0084] Cotton fabric was cut into 5 cm × 5 cm pieces and then soaked in 20% NaOH solution for 50 min under ultrasonic treatment to remove possible contaminants. 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 were weighed and added to 60 g of n-hexane, and stirred at room temperature for 2 h to achieve uniform mixing. The washed pure cotton fabric was then immersed in the prepared mixed solution at room temperature for 30 min, and then removed and irradiated under a UV lamp for 20 s to obtain superhydrophobic cotton fabric.

[0085] Example 4

[0086] Compared with Example 1, in step 3.3, the fabric is removed and irradiated under a UV lamp for 25 seconds, while the remaining steps are the same as in Example 1.

[0087] Example 5

[0088] Compared with Example 1, in step 3.3, the fabric is removed and irradiated under a UV lamp for 28 seconds, while the remaining steps are the same as in Example 1.

[0089] Example 6

[0090] Compared to Example 1, in step 3.3, the fabric is removed and irradiated under a UV lamp for 30 seconds; the remaining steps are the same as in Example 1.

[0091] The superhydrophobic cotton fabric prepared by this invention uses environmentally friendly and durable raw materials, has a simple process, and is suitable for large-scale production. It also possesses highly efficient oil-water separation capabilities, achieving a separation efficiency of over 98%. A simple and environmentally friendly method was used to prepare the UV-cured superhydrophobic cotton fabric. The resulting UV-cured superhydrophobic cotton fabric can withstand 100 abrasion cycles without significant reduction in hydrophobicity. Furthermore, the superhydrophobic cotton fabric is highly stable in strong acid and alkaline solutions and exhibits highly efficient oil-water separation for various oil-water mixtures. This simple synthesis technique has the advantage of being able to scale up the production of multifunctional fabrics and can be used for multifunctional oil-water separation.

Claims

1. A method for the preparation of ultraviolet light-cured superhydrophobic cotton fabric for oil-water separation, characterized by: Specifically comprising the following steps: Step 1, preparing a cashew phenolic-based ultraviolet curing resin; the specific process of step 1 is: sequentially adding 4, 4-diisocyanate dicyclohexyl methane, cashew phenol, pentaerythritol triacrylate and ethyl acetate with a molar ratio of 1:2:1:1~1:2.02:1:1 into a three-necked round-bottom flask, stirring the reaction mixture and heating to 75~85℃ for 1~3h under a nitrogen atmosphere, stopping the reaction, removing the unreacted solvent by rotary evaporation at 30~40℃ for 5~10min, and obtaining a cashew phenolic-based ultraviolet curing resin; Step 2, preparing γ-methacryloyloxypropyltrimethoxysilane modified silica; the specific process of step 2 is: Dispersing 1~3g of silica in 30~90mL of ethyl acetate, and adding 3~9g of 3-(methacryloyloxy)propyltrimethoxysilane dropwise, uniformly mixing by ultrasonic vibration for 30min, and adding ammonia water dropwise until the pH value of the solution is 10; subsequently, magnetically stirring the mixture at 80~90℃ for 8~12h, repeatedly washing the obtained product with anhydrous ethanol to remove unreacted 3-(methacryloyloxy)propyltrimethoxysilane, centrifuging the product, and vacuum drying at 80℃ for 10h to obtain a white powder, denoted as mSiO2; Step 3, preparing an ultraviolet curing super-hydrophobic cotton fabric for oil-water separation according to the products obtained in steps 1 and 2; the specific process of step 3 is: Step 3.1, cutting a cotton fabric woven from cotton fibers into a size of 5cm×5cm, and then immersing in a 10%~20% mass fraction NaOH solution under the action of ultrasonic waves for 30~50min to remove pollutants; Step 3.2, weighing 1~2g of the product obtained in step 1, 1~2g of the product obtained in step 2, 1~2g of polydimethylsiloxane and 0.1~0.2g of 2-hydroxy-2-methyl-1-phenyl-1-propanone into 50~60g of n-hexane, uniformly mixing by stirring at room temperature for 1~2h to obtain a mixed solution; Step 3.3, immersing the pure cotton fabric washed in step 3.1 into the mixed solution prepared in step 3.2 at room temperature for 10~30min, then taking out the fabric and irradiating under a ultraviolet lamp for 20~30s to obtain an ultraviolet curing super-hydrophobic cotton fabric.

2. A process for the preparation of ultraviolet light cured superhydrophobic cotton fabric for oil-water separation as claimed in claim 1, wherein: In step 1, the stirring rate under a nitrogen atmosphere is 400~600rpm.

3. The method for preparing UV-cured superhydrophobic cotton fabric for oil-water separation according to claim 2, characterized in that: In step 1, The above process is the synthesis process of the structural formula of the cashew phenolic-based ultraviolet curing resin.

4. The method for preparing UV-cured superhydrophobic cotton fabric for oil-water separation according to claim 3, characterized in that: In step 2, the centrifugation time is 10~30min.

5. An ultraviolet curing super-hydrophobic cotton fabric for oil-water separation, prepared by the method for preparing an ultraviolet curing super-hydrophobic cotton fabric for oil-water separation according to any one of claims 1~4.

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