Petroleum resin modified multistage micro-nano structure hydrophobic membrane and preparation method thereof

Abstract

The application provides a petroleum resin modified multistage micro-nano structure hydrophobic membrane and a preparation method. The petroleum resin modified multistage micro-nano structure hydrophobic membrane comprises a non-woven fabric base layer, a C5 petroleum resin layer, a high polymer organic film layer and a micro-nano structure C5 petroleum resin layer. The outermost layer of the upper and lower surfaces of the hydrophobic membrane is the micro-nano structure C5 petroleum resin layer, the non-woven fabric base layer is the middle layer, the upper and lower surfaces of the non-woven fabric base layer are tightly attached to the C5 petroleum resin layer, and the high polymer organic film layer is located between the C5 petroleum resin layer and the micro-nano structure C5 petroleum resin layer. The hydrophobic membrane provided by the application contains the micro-nano structure C5 petroleum resin layer, and the hydrophobic performance, self-cleaning performance, water resistance and corrosion resistance of the hydrophobic membrane are improved. The preparation cost is low, and the hydrophobic membrane is particularly suitable for oil-water separation and sewage purification fields.

Description

Technical Field

[0001] This invention relates to the field of hydrophobic film materials, and in particular to a petroleum resin-modified multi-level micro / nano-structured hydrophobic film and its preparation method. Background Technology

[0002] Hydrophobic membranes play a crucial role in numerous fields, with applications including, but not limited to, the following: In waterproofing materials: Hydrophobic membranes are widely used in the manufacture of waterproof clothing, waterproof bags, waterproof shoes, and waterproof coatings. These materials effectively resist the penetration of water and liquids, providing protection and comfort. In oil-water separation: In oily wastewater treatment, hydrophobic membranes are used to efficiently separate oil and water. This separation process is essential for environmental protection and resource recycling. In gas separation: Hydrophobic membranes play a key role in gas separation and membrane distillation, and can be used to separate gases of different components, showing broad application prospects. Furthermore, in anti-fouling: Hydrophobic membranes are often used to manufacture anti-stick coatings, effectively preventing dirt and deposits from adhering to surfaces, thereby maintaining the performance of equipment and structures.

[0003] C5 resin is a petroleum resin with a predominantly aliphatic chain structure, possessing a range of excellent properties, including: Low acid value: C5 resin has a low acid value, which helps improve its stability in various applications. Good miscibility: This resin is compatible with a variety of solvents, making it easy to handle in the preparation of products such as coatings and adhesives. Water and ethanol resistance: C5 resin exhibits good water and ethanol resistance, making it suitable for applications requiring high stability. Chemical resistance: Its resistance to chemical corrosion makes it ideal for a variety of fields. Viscosity adjustment and thermal stability: C5 resin exhibits good adjustability in viscosity and thermal stability, making it suitable for a variety of industrial applications.

[0004] Hydrophobic films surface-modified with C5 petroleum resin offer several advantages over hydrophobic films prepared by other methods: **Economy:** C5 petroleum resin is a relatively inexpensive raw material, making surface modification with it economical. This reduces the cost of preparing hydrophobic films. **Sustainability:** C5 petroleum resin is typically produced from renewable or sustainable raw materials, aligning with sustainability trends. **Hydrophobic Properties:** Surface-modified hydrophobic films with C5 petroleum resin generally exhibit good hydrophobic properties, resisting erosion from water, liquids, and humid environments. This is highly valuable in waterproofing materials, oil-water separation, and other applications requiring hydrophobicity. **Chemical Resistance:** C5 petroleum resin typically possesses good chemical resistance, maintaining stability in various chemical environments, thus improving film durability. **Surface Modification Control:** Surface modification with C5 petroleum resin provides better control over the film's surface properties. By adjusting the type and concentration of resin, hydrophobic properties can be tailored to meet the needs of different applications. Multifunctionality: In addition to hydrophobicity, C5 petroleum resin also has properties such as thickening, viscousness and adhesion. Therefore, the modified film can not only achieve hydrophobicity, but also provide multifunctional properties in other aspects.

[0005] Leveraging the numerous advantages of C5 resin, this invention incorporates micro / nano particles into the oleoresin coating, forming a hydrophobic film on a micro / nanostructured surface. This further enhances hydrophobic properties and offers additional advantages, such as: increased surface roughness: Micro / nanostructured particles or additives can increase surface roughness, thereby improving the coating's hydrophobicity. These microstructures can create more contact angles between air or liquid and the surface, making it easier for droplets to maintain a spherical shape and repel the surface. Improved self-cleaning properties: The presence of micro / nanostructures reduces the adsorption of dirt, dust, and other particles onto the surface. This improves the coating's self-cleaning performance, making it easier to clean and maintain. Anti-fouling properties: Micro / nano ions can reduce adhesion to the coating surface, making it less likely for droplets and particles to adhere. This improves the coating's anti-fouling properties and reduces maintenance costs. Optimized for specific applications: Different types of micro / nanostructure additives can be selected according to the needs of specific applications. For example, metal-organic framework materials can be used for desalination and removal of specific contaminants in water, such as heavy metal ions or organic pollutants, while silica or ceramic particles can enhance the surface's corrosion resistance. Improved coating durability: The addition of micro- and nano-structures can increase the durability of the coating, enabling it to maintain good performance over a long period of time.

[0006] In summary, the addition of micro and nanoparticles not only improves hydrophobic properties but also enhances various coating properties, making them more suitable for diverse applications, including waterproofing materials, oil-water separation, self-cleaning surfaces, and antifouling coatings. These advantages make the introduction of micro and nano structures a promising area for application in materials science and engineering. Summary of the Invention

[0007] The preparation of hydrophobic films has always been a core issue of great interest in research and industrial applications. This invention aims to fully utilize the unique hydrophobic properties and multi-level micro / nano structure of C5 petroleum resin, providing a simple and easy-to-implement process for preparing hydrophobic films. This innovative method not only improves the hydrophobic properties of the film but also opens up new avenues for further exploring the application potential of C5 petroleum resin in new fields.

[0008] The first aspect of this invention provides a petroleum resin-modified multi-level micro / nano-structured hydrophobic membrane. The petroleum resin-modified multi-level micro / nano-structured hydrophobic membrane comprises a non-woven fabric base layer, a C5 petroleum resin layer, a polymeric organic film layer, and a micro / nano-structured C5 petroleum resin layer. The outermost layer on both the upper and lower surfaces of the hydrophobic membrane is the micro / nano-structured C5 petroleum resin layer, and the non-woven fabric base layer is the intermediate layer. The C5 petroleum resin layer is tightly adhered to both the upper and lower surfaces of the non-woven fabric base layer. The polymeric organic film layer is located between the C5 petroleum resin layer and the micro / nano-structured C5 petroleum resin layer. The hydrophobic membrane provided by this invention, containing a micro / nano-structured C5 petroleum resin layer, improves the hydrophobic properties, self-cleaning properties, water resistance, and corrosion resistance of the hydrophobic membrane. It also has low manufacturing costs and is particularly suitable for oil-water separation and wastewater purification applications.

[0009] Furthermore, the micro / nano structured C5 petroleum resin layer incorporates micro / nano particles, which are one or more of hydrophobic alumina and hydrophobic silicon oxide, or may be hydrophobic silicon dioxide, alumina, micro / nano-scale ceramic materials, metal-organic framework materials, covalent organic frameworks, and micro / nano-structured carbon materials. Further, the micro / nano-structured carbon materials are one or more of graphene oxide, carbon nanotubes, carbon nanoparticles, graphene, multi-walled carbon nanotubes, and carbon nanofibers.

[0010] Furthermore, micro / nanostructured particles or additives can increase surface roughness, thereby improving the hydrophobicity of the coating. These microstructures can create a larger contact angle between air or liquid and the surface, making it easier for droplets to maintain their spherical shape and repel the surface. The presence of micro / nanostructures can reduce the adsorption of dirt, dust, and other particles onto the surface. This improves the self-cleaning properties of the coating, making it easier to clean and maintain. Micro / nano ions can reduce adhesion to the coating surface, so droplets and particles are less likely to adhere to it. This improves the coating's resistance to contamination and reduces maintenance costs.

[0011] Furthermore, the micro-nanoparticles are micro-nanoparticles with different particle size distributions. The micro-nanoparticles in the C5 petroleum resin layer of the micro-nano structure are composed of hydrophobic silica of 10 μm, 1 μm, 300 nm, and 20 nm in a mass ratio of 4:3:2:1.

[0012] Furthermore, the micro-nano structure of the C5 petroleum resin layer is composed of hydrophobic alumina in the mass ratio of 10 μm, 5 μm, 500 nm, and 100 nm, with a mass ratio of 2:2:1:1.

[0013] The second aspect of this invention provides a method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic membrane.

[0014] The preparation method includes the following steps:

[0015] S1. Prepare casting solution and coating solution, and prepare casting solution for forming polymer organic thin film layer, coating solution A for forming C5 petroleum resin layer and coating solution B for forming micro-nano structure C5 petroleum resin layer;

[0016] S2 coating non-woven fabric base layer, the non-woven fabric is immersed in coating solution A, the treatment time is 5-30 minutes, and then dried at low temperature;

[0017] S3 prepares a polymer organic film layer. On a clean glass plate, the casting solution is poured onto one side of the nonwoven fabric treated in step S2, and the casting solution is pushed out with a doctor blade at a speed of 1 mm / s-100 mm / s to form a polymer organic film layer. Then, the glass plate is immersed in the precipitation bath at a uniform speed. After the film is separated from the glass plate, it is rinsed and stored.

[0018] S4. The polymer organic film treated in step S3 is immersed in a C5 petroleum resin coating solution B containing mixed micro and nano particles for 5-60 minutes. The immersed film is then air-dried in a fume hood for 1-10 hours to obtain a petroleum resin modified multi-level micro-nano structure hydrophobic film.

[0019] Furthermore, the above-mentioned casting solution is prepared by mixing a polymeric material with a polar solvent to form a casting solution with a mass concentration of 10-20%. The casting solution is stirred at 60°C for 6-12 hours, and then heating and stirring are stopped to ensure that the air bubbles in the casting solution are completely removed. The polymeric material is one or more of polysulfone, polyethersulfone, cellulose acetate, polyetheretherketone, polymethyl methacrylate, polypropylene ether, and polyester. The polar solvent is one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and triethyl phosphate.

[0020] Furthermore, the coating solution A is obtained by mixing C5 petroleum resin with a non-polar solvent and stirring for 0.5-2 hours to completely dissolve the petroleum resin, and the weight concentration of C5 petroleum resin in the coating solution A is 2-20%.

[0021] Furthermore, the coating solution B is prepared by adding hydrophobic micro / nano particles to the coating solution A and uniformly mixing them at 30-50°C using an ultrasonic oscillator for 5-30 minutes. The hydrophobic micro / nano particles are hydrophobic silica, alumina, micro / nano-scale ceramic materials, metal-organic frameworks, covalent organic frameworks, and micro / nano-structured carbon materials. Further, the micro / nano-structured carbon materials are one or more of graphene oxide, carbon nanotubes, carbon nanoparticles, graphene, multi-walled carbon nanotubes, and carbon nanofibers. The mass concentration of the hydrophobic micro / nano particles in the coating solution B is 0.05-5%.

[0022] Furthermore, the C5 petroleum resin used in the preparation method has a softening point of 100-105℃.

[0023] The beneficial effects of this invention are as follows:

[0024] The petroleum resin-modified multi-level micro / nano-structured hydrophobic membrane provided by this invention comprises a nonwoven fabric base layer, a C5 petroleum resin layer, a polymer organic film layer, and a micro / nano-structured C5 petroleum resin layer. The outermost layer on both the upper and lower surfaces of the hydrophobic membrane is the micro / nano-structured C5 petroleum resin layer, and the nonwoven fabric base layer serves as the intermediate layer. The C5 petroleum resin layer is tightly adhered to both the upper and lower surfaces of the nonwoven fabric base layer. The polymer organic film layer is located between the C5 petroleum resin layer and the micro / nano-structured C5 petroleum resin layer. The hydrophobic membrane provided by this invention, containing a micro / nano-structured C5 petroleum resin layer, improves the hydrophobic properties, self-cleaning properties, water resistance, and corrosion resistance of the hydrophobic membrane, while maintaining low manufacturing cost.

[0025] The addition of micro / nanoparticles provided by this invention not only improves hydrophobic properties but also enhances various coating properties, making it more suitable for a wide range of applications, including waterproofing materials, oil-water separation, self-cleaning surfaces, and antifouling coatings. These advantages make the introduction of micro / nano structures a promising area for application in materials science and engineering.

[0026] The petroleum resin-modified multi-level micro / nano-structured hydrophobic film and its preparation method provided by this invention also have the following advantages:

[0027] Simple and easy-to-operate process: The hydrophobic membrane preparation process provided by this invention is simple to operate and easy to implement, requiring no complex equipment or advanced technology, thus reducing preparation costs and technical barriers.

[0028] Enhanced hydrophobicity: Utilizing the hydrophobic properties of C5 petroleum resin and its multi-level micro / nano structure, the membrane prepared by this invention exhibits excellent water resistance and antifouling properties, effectively preventing the penetration of water or liquids and maintaining surface dryness and cleanliness. Typically, surface modification can increase the film's surface contact angle by 40-70%.

[0029] Potential for applications in multiple fields: This invention provides ideas and methods for new applications of C5 petroleum resin, giving it broad application potential in multiple fields such as waterproof materials, oil-water separation, gas separation, and pollution prevention.

[0030] Environmental protection and resource recycling: The application of hydrophobic membranes in oily wastewater treatment is expected to improve the efficiency of environmental protection and resource recycling, and help solve important problems in oily wastewater treatment.

[0031] Performance of petroleum resin: The C5 petroleum resin used in this invention has excellent properties, such as low acid value, miscibility, water resistance and chemical corrosion resistance, making it an ideal material for preparing high-efficiency hydrophobic films.

[0032] In summary, this invention not only creates a simple and effective process for preparing hydrophobic films, but also provides strong support for new applications of C5 petroleum resins, and is expected to improve product performance and quality in multiple fields, while promoting environmental protection and resource recycling. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the hydrophobic membrane of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the following description is provided in conjunction with the embodiments and the appendix. Figure 1 The present invention will be described in further detail below.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. It should be understood that the following description is merely illustrative and is not intended to limit the invention.

[0036] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover a non-exclusive inclusion. A composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0037] The phrase "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for conventional impurities associated with them. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0038] When a dosage, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including ranges “1 to 4,” “1 to 3,” “1 to 2,” “1 to 2 and 4 to 5,” “1 to 3 and 5,” etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0039] In some instances, approximate terms may correspond to the instrument precision of the measured values. In this specification and claims, scope definitions may be combined and / or interchanged. Unless otherwise stated, these scopes include all subscopes contained therein.

[0040] The indefinite articles “a” and “an” preceding an element or component of this invention do not impose any limitation on the number of elements or components (i.e., the number of times they appear). Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0041] The terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" used in this invention refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms are not necessarily directed at the same embodiment or example. Furthermore, the technical features involved in the various embodiments of the invention can be combined with each other as long as they do not conflict with each other.

[0042] Unless otherwise specified, the raw materials and equipment used in this invention can be purchased from the market or are commonly used in the field. Unless otherwise specified, the methods in the embodiments are conventional methods in the field.

[0043] This invention relates to a multi-level micro / nano-structured hydrophobic film modified with C5 petroleum resin and its preparation method, aiming to improve the surface properties of the film and enhance the stability of the contact angle. This method can be widely applied in various fields, including coatings, coatings, and thin film preparation.

[0044] Step 1: Preparation of casting solution

[0045] In a 250mL reagent bottle, a certain mass of a polymer (such as polysulfone, polyethersulfone, cellulose acetate, polyetheretherketone, polymethyl methacrylate, polypropylene ether, polyester, etc.) is mixed with a certain mass of a polar solvent (such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, triethyl phosphate, etc.) to form a casting solution with a mass concentration of 10-20%. The casting solution is stirred at 60℃ for 6-12 hours, and then heating and stirring are stopped to ensure that air bubbles in the casting solution are completely removed.

[0046] Step 2: Preparation of Coating Solution

[0047] In a 1000mL reagent bottle, a certain mass of C5 petroleum resin is mixed with a certain mass of nonpolar solvent (such as n-hexane) and stirred for 0.5-2 hours to completely dissolve the petroleum resin, forming a coating solution A with a mass concentration of 2-20%. Add 0.05-5% of a micro / nano hydrophobic additive, such as hydrophobic silica, alumina, micro / nano-scale ceramic materials, metal-organic frameworks, covalent organic frameworks, and micro / nano-scale carbon materials (such as graphene oxide, carbon nanotubes, carbon nanoparticles, graphene, multi-walled carbon nanotubes, and carbon nanofibers), to adjust the surface properties of the film. The mixture is then homogenized using an ultrasonic oscillator at 30-50℃ for 5-30 minutes to form coating solution B.

[0048] Step 3: Coating the non-woven fabric base layer

[0049] The nonwoven fabric is immersed in coating solution A for 5-30 minutes and then dried at low temperature to impart hydrophobicity to the nonwoven fabric base layer, while also serving as a support layer for the preparation of organic films to ensure good mechanical strength.

[0050] Step 4: Preparation of Polymer Organic Thin Films

[0051] On a clean glass plate, pour the casting solution onto one side of a nonwoven fabric and use a doctor blade to spread the casting solution at a speed of 1 mm / s to 100 mm / s to form a thin film. Then, immerse the glass plate in the precipitation bath at a uniform speed. After the film separates from the glass plate, rinse and store it.

[0052] Step 5: Film impregnation

[0053] The prepared polymeric organic film was immersed in a C5 petroleum resin coating solution B containing mixed micro and nanoparticles for 5-60 minutes. Subsequently, the immersed film was air-dried naturally in a fume hood for 1-10 hours.

[0054] Step Six: Surface Characteristic Testing

[0055] The hydrophobicity of the surface of the organic film coated with C5 petroleum resin was tested, and the contact angle of the film surface was measured using a contact angle meter.

[0056] This improved technical solution can significantly enhance the surface properties of polymer films, enabling them to maintain a more stable contact angle under different time and temperature conditions. It holds promise for applications in coatings, coatings, and film preparation, thereby improving product performance and quality.

[0057] The following description, in conjunction with specific implementation methods, provides further details.

[0058] Example 1

[0059] Step 1: Preparation of casting solution

[0060] 1. Take a 250mL reagent bottle and add 16g of polyethersulfone (PES) and 84g of N-methylpyrrolidone (NMP).

[0061] 2. Stir and mix to ensure that the polyethersulfone is completely dissolved in NMP to form a casting solution with a mass concentration of 16%.

[0062] 3. Place the casting solution on a 60°C constant temperature stirrer and stir continuously for 8 hours. Then stop heating and stirring and let it stand at room temperature for more than 6 hours to remove air bubbles.

[0063] Step 2: Preparation of Coating Solution

[0064] 1. Take a 1000mL reagent bottle and add 50g of C5 petroleum resin and 950g of n-hexane.

[0065] 2. Mix and stir to completely dissolve the C5 petroleum resin in n-hexane to form a coating solution A with a mass concentration of 5%.

[0066] 3. Divide coating solution A into two parts. Add 10 μm, 1 μm, 300 nm and 20 nm hydrophobic silica to one part in a ratio of 4:3:2:1. Mix the two parts at 40°C for 20 minutes using an ultrasonic oscillator to form coating solution B with a mass concentration of 2%.

[0067] Step 3: Coating the non-woven fabric base layer

[0068] 1. Cut the nonwoven fabric to the required size and immerse it in the coating solution A prepared above for 15 minutes.

[0069] 2. Remove the impregnated nonwoven fabric, place it in a fume hood and let it stand for 15 minutes, then dry it with warm air to give the nonwoven fabric base layer hydrophobicity, while also serving as a support layer for the preparation of organic membranes to ensure good mechanical strength.

[0070] Step 4: Preparation of Polymer Organic Thin Films

[0071] 1. On a clean glass surface, pour the casting solution onto one side of the nonwoven fabric and use a doctor blade to spread the casting solution at a speed of 10 mm / s to form a thin film.

[0072] 2. Immerse the glass plate in water. Once the film separates from the glass plate, rinse and store it.

[0073] Step 5: Film impregnation

[0074] 1. The prepared polymeric organic film is immersed in a C5 petroleum resin coating solution B containing mixed micro- and nano-silica particles for 15 minutes.

[0075] 2. After impregnation, let the film stand in a fume hood for half an hour, and then air dry for 1 hour.

[0076] Step Six: Surface Characteristic Testing

[0077] The hydrophobicity of the surface of the organic film coated with C5 petroleum resin was tested, and the contact angle of the film surface was measured using a contact angle meter.

[0078] Test results: The contact angle of the organic film surface coated with C5 petroleum resin containing micro-nano silica particles is 140°.

[0079] Comparative Example 1

[0080] The difference between this comparative example and Example 1 is that the coating solution B in step (3) does not contain 10 μm, 1 μm, 300 nm and 20 nm hydrophobic silica in a ratio of 4:3:2:1, but only 10 μm hydrophobic silica.

[0081] The contact angle of the thin film obtained in this comparative example is 121°.

[0082] Comparative Example 2

[0083] The difference between this comparative example and Example 1 is that the coating solution B in step (3) does not contain 10 μm, 1 μm, 300 nm and 20 nm hydrophobic silica in a ratio of 4:3:2:1, but only 1 μm hydrophobic silica.

[0084] The contact angle of the thin film obtained in this comparative example is 109°.

[0085] Comparative Example 3

[0086] The difference between this comparative example and Example 1 is that the coating solution B in step (3) does not contain 10 μm, 1 μm, 300 nm and 20 nm hydrophobic silica in a ratio of 4:3:2:1, but only 300 nm hydrophobic silica.

[0087] The contact angle of the thin film obtained in this comparative example is 101°.

[0088] Comparative Example 4

[0089] The difference between this comparative example and Example 1 is that the coating solution B in step (3) does not contain 10 μm, 1 μm, 300 nm and 20 nm hydrophobic silica in a ratio of 4:3:2:1, but only 20 nm hydrophobic silica.

[0090] The contact angle of the thin film obtained in this comparative example is 95°.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 1 is that step (5) is omitted, and the coating solution B containing micro-nano particles is not used to coat the film surface.

[0093] The contact angle of the thin film obtained in this comparative example is 85°.

[0094] Example 2

[0095] Step 1: Preparation of casting solution

[0096] 1. Take a 250mL reagent bottle and add 18g of polyetheretherketone and 82g of N,N-dimethylformamide (DMF).

[0097] 2. Stir and mix to ensure that the polyethersulfone is completely dissolved in NMP to form a casting solution with a mass concentration of 18%.

[0098] 3. Place the casting solution on a 60°C constant temperature stirrer and stir continuously for 8 hours. Then stop heating and stirring and let it stand at room temperature for more than 6 hours to remove air bubbles.

[0099] Step 2: Preparation of Coating Solution

[0100] 1. Take a 1000mL reagent bottle and add 100g of C5 petroleum resin and 900g of n-hexane.

[0101] 2. Mix and stir to completely dissolve the C5 petroleum resin in n-hexane to form a coating solution A with a mass concentration of 10%.

[0102] 3. Divide coating solution A into two parts. Add hydrophobic alumina of 10 μm, 5 μm, 500 nm and 100 nm to one part in a ratio of 2:2:1:1. Mix the two parts at 40°C for 20 minutes using an ultrasonic oscillator to form coating solution B with a mass concentration of 3%.

[0103] Step 3: Coating the non-woven fabric base layer

[0104] 1. Cut the nonwoven fabric to the required size and immerse it in the coating solution A prepared above for 15 minutes.

[0105] 2. Remove the impregnated nonwoven fabric, place it in a fume hood and let it stand for 15 minutes, then dry it with warm air to give the nonwoven fabric base layer hydrophobicity, while also serving as a support layer for the preparation of organic membranes to ensure good mechanical strength.

[0106] Step 4: Preparation of Polymer Organic Thin Films

[0107] 1. On a clean glass surface, pour the casting solution onto one side of the nonwoven fabric and use a doctor blade to spread the casting solution at a speed of 10 mm / s to form a thin film.

[0108] 2. Immerse the glass plate in water. Once the film separates from the glass plate, rinse and store it.

[0109] Step 5: Film impregnation

[0110] 1. The prepared polymeric organic film is immersed in a C5 petroleum resin coating solution B containing mixed micro- and nano-alumina particles for 15 minutes.

[0111] 2. After impregnation, let the film stand in a fume hood for half an hour, and then air dry for 1 hour.

[0112] Step Six: Surface Characteristic Testing

[0113] The hydrophobicity of the surface of the organic film coated with C5 petroleum resin was tested, and the contact angle of the film surface was measured using a contact angle meter.

[0114] Test results: The contact angle of the organic film surface coated with C5 petroleum resin containing micro-nano alumina particles is 145°.

[0115] Comparative Example 5

[0116] The difference between this comparative example and Example 2 is that the coating solution B in step (3) does not contain 10 μm, 5 μm, 500 nm and 100 nm hydrophobic alumina in a ratio of 2:2:1:1, but only 10 μm hydrophobic alumina.

[0117] The contact angle of the thin film obtained in this comparative example is 123°.

[0118] Comparative Example 6

[0119] The difference between this comparative example and Example 2 is that the coating solution B in step (3) does not contain 10 μm, 5 μm, 500 nm and 100 nm hydrophobic alumina in a ratio of 2:2:1:1, but only 5 μm hydrophobic alumina.

[0120] The contact angle of the thin film obtained in this comparative example is 112°.

[0121] Comparative Example 7

[0122] The difference between this comparative example and Example 2 is that the coating solution B in step (3) does not contain 10 μm, 5 μm, 500 nm and 100 nm hydrophobic alumina in a ratio of 2:2:1:1, but only 500 nm hydrophobic alumina.

[0123] The contact angle of the thin film obtained in this comparative example is 105°.

[0124] Comparative Example 8

[0125] The difference between this comparative example and Example 2 is that the coating solution B in step (3) does not contain 10 μm, 5 μm, 500 nm and 100 nm hydrophobic alumina in a ratio of 2:2:1:1, but only 100 nm hydrophobic alumina.

[0126] The contact angle of the thin film obtained in this comparative example is 94°.

[0127] Comparative Example 9

[0128] The difference between this comparative example and Example 2 is that step (5) is omitted, and the coating solution B containing micro-nano particles is not used to coat the film surface.

[0129] The contact angle of the thin film obtained in this comparative example is 83°.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A petroleum resin-modified multi-level micro / nano-structured hydrophobic membrane, comprising a nonwoven fabric base layer, a C5 petroleum resin layer, a polymeric organic film layer, and a micro / nano-structured C5 petroleum resin layer. The outermost layer on the upper and lower surfaces of the hydrophobic membrane is the micro / nano-structured C5 petroleum resin layer, the nonwoven fabric base layer is the intermediate layer, the C5 petroleum resin layer is tightly adhered to both the upper and lower surfaces of the nonwoven fabric base layer, the polymeric organic film layer is located on one side of the nonwoven fabric base layer, and the C5 petroleum resin layer is located on one side of the nonwoven fabric base layer. Between the oleoresin layer and the micro / nanostructured C5 petroleum resin layer; the micro / nanostructured C5 petroleum resin layer is doped with hydrophobic micro / nano particles, wherein the composition of the micro / nanostructured C5 petroleum resin layer is 10 μm, 1 μm, 300 nm, and 20 nm hydrophobic silica in a mass ratio of 4:3:2:1 or the composition of the micro / nanostructured C5 petroleum resin layer is 10 μm, 5 μm, 500 nm, and 100 nm hydrophobic alumina in a mass ratio of 2:2:1:

1.

2. A method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic film according to claim 1, characterized in that, The preparation method includes the following steps: S1. Prepare casting solution and coating solution, and prepare casting solution for forming polymer organic thin film layer, coating solution A for forming C5 petroleum resin layer and coating solution B for forming micro-nano structure C5 petroleum resin layer; S2 Coating of nonwoven fabric base layer: Immerse the nonwoven fabric in coating solution A for 5-30 minutes, and then dry at low temperature; S3 Preparation of polymer organic film layer: On a clean glass plate, pour the casting solution onto one side of the nonwoven fabric treated in step S2, and use a doctor blade to spread the casting solution at a speed of 1 mm / s-100 mm / s to form a polymer organic film layer. Then, immerse the glass plate in the precipitation bath at a uniform speed. After the film separates from the glass plate, rinse and store it. S4. The polymeric organic film treated in step S3 is immersed in a C5 petroleum resin coating solution B containing mixed micro- and nano-particles for 5-60 minutes. The immersed film is then air-dried in a fume hood for 1-10 hours to obtain a petroleum resin-modified multi-level micro- and nano-structured hydrophobic film.

3. The method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic film according to claim 2, characterized in that, The casting solution is prepared by mixing a polymer with a polar solvent to form a casting solution with a mass concentration of 10-20%. The casting solution is stirred at 60°C for 6-12 hours, and then heating and stirring are stopped to ensure that the air bubbles in the casting solution are completely removed. The polymer is one or more of polysulfone, cellulose acetate, polyetheretherketone, polymethyl methacrylate, and polyester. The polar solvent is one or more of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and triethyl phosphate.

4. The method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic film according to claim 2, characterized in that, The coating solution A is obtained by mixing C5 petroleum resin with a non-polar solvent and stirring for 0.5-2 hours to completely dissolve the petroleum resin. The weight concentration of C5 petroleum resin in the coating solution A is 2-20%.

5. The method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic film according to claim 4, characterized in that, The coating solution B is prepared by adding hydrophobic micro / nano particles to the coating solution A and mixing them uniformly for 5-30 minutes at a temperature of 30-50°C using an ultrasonic oscillator. The hydrophobic micro / nano particles are either silica or alumina, which have hydrophobic properties. The mass concentration of the hydrophobic micro / nano particles in the coating solution B is 0.05-5%.

6. A method for preparing a petroleum resin-modified multi-level micro / nano-structured hydrophobic film according to any one of claims 2-5, characterized in that, The C5 petroleum resin used in the preparation method has a softening point of 100-105℃.

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