Super-hydrophobic nano protective material and preparation method thereof

Abstract

The application relates to the technical field of functional nano-coating materials, in particular to super-hydrophobic nano protective material and a preparation method thereof, which comprises the following components: N-alkyl carbazole polysiloxane copolymer 100 parts, isocyanate modified silicon dioxide 10-70 parts, polyphenyl polymethylene polyisocyanate 3.2-4.7 parts, fluorinated modified nanoparticles 5-15 parts, mesoporous silicon dioxide 5-20 parts and silane coupling agent 3-8 parts. The material has excellent super-hydrophobic performance, good mechanical durability, high-temperature resistance and chemical stability, and has the advantages of simple preparation process, low cost and environmental friendliness, and can be widely applied to surface protection of various substrates.

Description

Technical Field

[0001] This invention relates to the field of functional nanocoating materials technology, and in particular to a superhydrophobic nanoprotective material and its preparation method. Background Technology

[0002] Superhydrophobic surfaces are special wettable surfaces with a water contact angle greater than 150° and a roll-off angle less than 10°, exhibiting excellent water-repellent properties. This phenomenon originates from the "lotus effect" in nature; its microstructure traps air and reduces the water-solid contact area, making water droplets roll off easily. Such surfaces have broad application prospects in waterproof coatings, anti-corrosion coatings, self-cleaning surfaces, and anti-icing materials.

[0003] Currently, methods for preparing superhydrophobic materials mainly include physical vapor deposition, sol-gel method, template method, and chemical etching. However, existing technologies still have many limitations: for example, some methods produce superhydrophobic surfaces with poor mechanical strength, which lose their superhydrophobic properties with slight wear; some methods require complex equipment or high-temperature treatment, which are costly and difficult to apply on a large scale; and other methods rely on materials with poor environmental performance, such as fluorinated compounds.

[0004] Patent document CN110257801A discloses a superhydrophobic coating with a porous titanium carbide nanowall structure, but its preparation process requires high-temperature vapor deposition, which is costly and difficult to handle large-sized workpieces. Patent document CN114797757A reports a method for preparing superhydrophobic nanomaterials using industrial by-products. Although the cost is lower, the durability and stability of its hydrophobic properties need to be improved.

[0005] Although the superhydrophobic coating mentioned in patent document CN110257801A has a large contact angle, it lacks mechanical durability and has a complex preparation process.

[0006] Existing superhydrophobic materials suffer from a tradeoff between mechanical durability, complex fabrication processes, and environmental friendliness. There is an urgent need to develop a novel nanomaterial that combines excellent superhydrophobic properties, good mechanical strength, simple fabrication processes, and environmental friendliness. Summary of the Invention

[0007] The purpose of this invention is to provide a superhydrophobic nanoprotective material and its preparation method. This material has excellent superhydrophobic properties, good mechanical durability, high temperature resistance and chemical stability. Moreover, the preparation process is simple, low cost and environmentally friendly, and it can be widely used for surface protection of various substrates.

[0008] To achieve the above objectives, in a first aspect, the present invention provides a superhydrophobic nanoprotective material, comprising, by weight, the following components: 100 parts of N-alkylcarbazole polysiloxane copolymer, 10-70 parts of isocyanate-modified silica, 3.2-4.7 parts of polyphenyl polymethylene polyisocyanate, 5-15 parts of fluorinated modified nanoparticles, 5-20 parts of mesoporous silica, and 3-8 parts of silane coupling agent.

[0009] The N-alkylcarbazole polysiloxane copolymer has a rigid and stable carbazole structure in its molecular backbone, and its thermal decomposition temperature is not lower than 300℃; the isocyanate-modified silica has a particle size range of 20-100nm, and it forms a micro-nano protrusion structure in the polysiloxane body; the fluorinated modified nanoparticles are silica or silicon carbide particles grafted with fluorosilane, with a contact angle greater than 150° and a roll-off angle less than 10°.

[0010] Secondly, the present invention also provides a method for preparing a superhydrophobic nanoprotective material, comprising: A double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole were mixed in a reactor at a mass ratio of 100:(6.5-9.2) and reacted at 55-80°C for 12-18 hours to obtain a copolymer. Nanoparticles were mixed with fluorosilane at a mass ratio of 1:0.5-1.0 and fluorinated under acidic conditions to obtain fluorinated modified nanoparticles. The copolymer was mixed with isocyanate-modified silica, polyphenyl polymethylene polyisocyanate, the fluorinated modified nanoparticles, mesoporous silica and silane coupling agent, and dispersed evenly to obtain a superhydrophobic nanoprotective material.

[0011] The fluorosilane is 1H,1H,2H,2H-perfluorodecyltriethoxysilane, the reaction temperature is 60-80℃, and the reaction time is 4-8 hours.

[0012] The reactor includes a support assembly, a mixing assembly, and a temperature control assembly. The support assembly includes a base, a mixing shell, a cover plate, and a feeding structure. The mixing shell is fixed on the base, the cover plate is slidably disposed above the mixing shell, and the feeding structure is disposed on the cover plate. The mixing assembly includes a dispersion structure and a wall scraping structure. The dispersion structure is rotatably disposed within the mixing shell for dispersing double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole. The wall scraping structure is rotatably disposed within the mixing shell for scraping the mixture adhering to the wall of the mixing shell.

[0013] The dispersing structure includes a dispersing disk, a rotating rod, and a rotating motor. The rotating rod is rotatably mounted on the cover plate. The dispersing disk is fixedly connected to the rotating rod and located inside the rotating rod. The output end of the rotating motor is connected to the rotating rod.

[0014] The wall scraping structure includes a support ring, a rotating sleeve, a support rod, a wall scraping rod, and a driver. The support ring is fixed to the cover plate. The rotating sleeve is rotatably connected to the support ring and is located on one side of the support ring. The support rod is fixed to the rotating sleeve. The wall scraping rod is disposed on the support rod and contacts the inner wall of the mixing shell. The driver is used to drive the rotating sleeve to rotate.

[0015] The scraping rod includes a scraping rod body, a sliding rod, and a spring. The sliding rod is slidably disposed on the support rod, and the spring is disposed between the sliding rod and the support rod. The scraping rod body is fixed to the sliding rod.

[0016] The driver includes a drive motor, a drive gear, and a driven gear ring. The driven gear ring is fixed to the rotating sleeve. The drive gear meshes with the driven gear ring. The output end of the drive motor is connected to the drive gear.

[0017] The temperature control component includes a spiral flow guide jacket, a heater, and a temperature sensor. The spiral flow guide jacket is disposed on the outside of the mixing shell, the heater is connected to the spiral flow guide jacket, and the temperature sensor is disposed inside the mixing shell to obtain the reaction temperature and control the heating power of the heater.

[0018] The present invention provides a superhydrophobic nanomaterial and its preparation method. Compared with the prior art, the present invention has the following advantages: The superhydrophobic nanomaterials prepared in this invention exhibit extremely high water contact angles (greater than 150°) and extremely small roll-off angles (less than 10°), demonstrating excellent superhydrophobic properties. This is mainly attributed to the construction of micro-nano hierarchical rough structures and the introduction of low surface energy materials in the material.

[0019] Through the cross-linking of isocyanate-modified silica and polyphenyl polymethylene polyisocyanate, the material forms a stable three-dimensional network structure, enhancing the mechanical strength and wear resistance of the coating. After 1000 cycles of wear testing, the mass loss was only 13.6%, indicating its excellent mechanical durability.

[0020] The carbazole structure in the main chain of N-alkylcarbazole polysiloxane copolymer has rigidity and stability, which can increase the thermal decomposition temperature of the material and enable it to maintain good superhydrophobic properties even at high temperatures.

[0021] The material maintains stable superhydrophobic properties in various acidic and alkaline environments, making it suitable for long-term use in harsh environments.

[0022] The preparation method used in this invention does not require complex equipment or high temperature and high pressure conditions. The process is simple, the cost is low, and it is suitable for large-scale industrial production.

[0023] The solvents used in the material preparation process are mainly environmentally friendly solvents such as ethanol, and there is no need to use harmful substances such as fluorinated compounds, thus reducing the environmental burden. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0025] Figure 1 This is a structural diagram of the fourth embodiment of the present invention.

[0026] Figure 2 This is a left-side structural diagram of the fourth embodiment of the present invention.

[0027] Figure 3 This is a cross-sectional structural diagram of the fourth embodiment of the present invention.

[0028] Figure 4 yes Figure 3 A magnified view of detail A.

[0029] Figure 5 This is a longitudinal cross-sectional view of the fourth embodiment of the present invention.

[0030] Figure 6 This is a flowchart of the preparation method of the superhydrophobic nanoprotective material of the present invention.

[0031] In the figure: base 101, mixing shell 102, cover plate 103, feeding structure 104, dispersing structure 105, wall scraping structure 106, dispersing disc 107, rotating rod 108, rotating motor 109, support ring 110, rotating sleeve 111, support rod 112, wall scraping rod 113, driver 114, wall scraping rod body 115, sliding rod 116, spring 117, drive motor 118, drive gear 119, driven gear ring 120, spiral guide jacket 121, heater 122, temperature sensor 123. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0033] Example 1: Please refer to Figure 6This embodiment provides a superhydrophobic nanoprotective material, which, by weight, consists of: 100 parts of N-alkylcarbazole polysiloxane copolymer, 30 parts of isocyanate-modified silica, 3.5 parts of polyphenyl polymethylene polyisocyanate, 8 parts of fluorinated modified silica nanoparticles, 10 parts of mesoporous silica, and 4 parts of silane coupling agent KH-550.

[0034] Its preparation method includes the following steps: Preparation of N-alkylcarbazole polysiloxane copolymer: Bis-terminated epoxy-terminated polysiloxane and 3,6-diamino-N-hexylcarbazole were mixed in a reactor at a mass ratio of 100:7.0 and reacted at 65°C for 15 hours to obtain N-alkylcarbazole polysiloxane copolymer.

[0035] Preparation of fluorinated modified silica nanoparticles: Silica nanoparticles with a particle size of 30 nm were mixed with 1H,1H,2H,2H-perfluorodecyltriethoxysilane at a mass ratio of 1:0.6 and reacted at 70 °C for 6 hours in an acetic acid buffer solution with pH=5 to obtain fluorinated modified silica nanoparticles.

[0036] Preparation of composite material: The copolymer obtained in step 1 was mixed with isocyanate modified silica, polyphenyl polymethylene polyisocyanate, fluorinated modified silica nanoparticles obtained in step 2, mesoporous silica and silane coupling agent KH-550, and dispersed in a high-speed disperser at a speed of 1000 r / min for 40 minutes until the mixture was uniform, to obtain superhydrophobic nanoprotective material.

[0037] The superhydrophobic nanomaterial prepared in this embodiment was diluted with ethanol to a solid content of 5%, and then coated onto an aluminum plate using a spray coating method. It was cured at 80°C for 30 minutes to form a protective layer with a thickness of approximately 15 μm. Testing showed that the water contact angle of this protective layer was 158°, the roll-off angle was 5°, and after 500 friction cycles, the contact angle remained above 152°, demonstrating excellent superhydrophobic properties and mechanical durability.

[0038] Example 2: This example provides a superhydrophobic nanoprotective material, which, by weight, consists of: 100 parts of N-alkylcarbazole polysiloxane copolymer, 50 parts of isocyanate-modified silica, 4.0 parts of polyphenyl polymethylene polyisocyanate, 12 parts of fluorinated modified silicon carbide nanoparticles, 15 parts of mesoporous silica, and 6 parts of silane coupling agent KH-570.

[0039] Its preparation method includes the following steps: Preparation of N-alkylcarbazole polysiloxane copolymer: Bis-terminated epoxy-terminated polysiloxane and 3,6-diamino-N-octylcarbazole were mixed in a reactor at a mass ratio of 100:8.0 and reacted at 70°C for 14 hours to obtain N-alkylcarbazole polysiloxane copolymer.

[0040] Preparation of fluorinated modified silicon carbide nanoparticles: Silicon carbide nanoparticles with a particle size of 50 nm were mixed with 1H,1H,2H,2H-perfluorodecyltriethoxysilane at a mass ratio of 1:0.8 and reacted at 75 °C for 5 hours under acidic conditions of pH=4.5 to obtain fluorinated modified silicon carbide nanoparticles.

[0041] Preparation of composite material: The copolymer obtained in step 1 was mixed with isocyanate modified silica, polyphenyl polymethylene polyisocyanate, fluorinated modified silicon carbide nanoparticles obtained in step 2, mesoporous silica and silane coupling agent KH-570, and dispersed in a high-speed disperser at a speed of 1200 r / min for 30 minutes until the mixture was uniform, to obtain superhydrophobic nanoprotective material.

[0042] The superhydrophobic nanomaterial prepared in this embodiment was coated onto a copper substrate using a dip-coating method and cured at 100°C for 20 minutes to form a protective layer with a thickness of approximately 20 μm. Testing showed that the protective layer had a water contact angle of 156° and a roll-off angle of 7°. After immersion in a 3.5% NaCl solution for 240 hours, it still maintained a contact angle of over 150°, demonstrating excellent superhydrophobic and anti-corrosion properties.

[0043] Example 3: This example provides a superhydrophobic nanoprotective material, which, by weight, consists of: 100 parts of N-alkylcarbazole polysiloxane copolymer, 40 parts of isocyanate-modified silica, 3.8 parts of polyphenyl polymethylene polyisocyanate, 10 parts of fluorinated modified silica nanoparticles, 12 parts of mesoporous silica, and 5 parts of silane coupling agent KH-792.

[0044] Its preparation method includes the following steps: Preparation of N-alkylcarbazole polysiloxane copolymer: Bis-terminated epoxy-terminated polysiloxane and 3,6-diamino-N-dodecylcarbazole were mixed in a reactor at a mass ratio of 100:7.5 and reacted at 60°C for 16 hours to obtain N-alkylcarbazole polysiloxane copolymer.

[0045] Preparation of fluorinated modified silica nanoparticles: Silica nanoparticles with a particle size of 40 nm were mixed with 1H,1H,2H,2H-perfluorodecyltriethoxysilane at a mass ratio of 1:0.7 and reacted at 65 °C for 7 hours under acidic conditions of pH=5.5 to obtain fluorinated modified silica nanoparticles.

[0046] Preparation of composite material: The copolymer obtained in step 1 was mixed with isocyanate modified silica, polyphenyl polymethylene polyisocyanate, fluorinated modified silica nanoparticles obtained in step 2, mesoporous silica and silane coupling agent KH-792, and dispersed in a high-speed disperser at a speed of 900 r / min for 50 minutes until the mixture was uniform, to obtain superhydrophobic nanoprotective material.

[0047] The superhydrophobic nanomaterial prepared in this embodiment was used for the protection of electronic circuit boards. It was coated onto the surface of the printed circuit board using a spin-coating method and cured at 80°C for 25 minutes to form a protective layer with a thickness of approximately 10 μm. Testing showed that the water contact angle of this protective layer was 159° and the roll-off angle was 4°, effectively preventing moisture penetration and chemical corrosion without affecting the heat dissipation performance of electronic components.

[0048] Table 2: Performance Comparison of Superhydrophobic Nanomaterials in Examples 1-3 Performance indicators Example 1 Example 2 Example 3 Test Standards Water contact angle (°) 158 156 159 GB / T 30447-2013 Roll angle (°) 5 7 4 GB / T 30447-2013 Abrasion resistance (times) >500 >600 >550 Friction test, contact angle >150° Salt spray resistance (h) >240 >300 >260 GB / T 1771-2007 High temperature resistance (°C) >300 >280 >320 GB / T 1735-2009 The above embodiments illustrate that the superhydrophobic nanomaterials provided by the present invention have excellent superhydrophobic properties, good mechanical durability, corrosion resistance and high temperature resistance, and can be widely used in various occasions requiring surface protection.

[0049] Example 4: Please refer to Figures 1-5 The reactor includes a support assembly, a mixing assembly, and a temperature control assembly. The support assembly includes a base 101, a mixing shell 102, a cover plate 103, and a feeding structure 104. The mixing shell 102 is fixed on the base 101, the cover plate 103 is slidably disposed above the mixing shell 102, and the feeding structure 104 is disposed on the cover plate 103. The mixing assembly includes a dispersion structure 105 and a wall scraping structure 106. The dispersion structure 105 is rotatably disposed within the mixing shell 102 for dispersing double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole. The wall scraping structure 106 is rotatably disposed within the mixing shell 102 for scraping the mixture adhering to the wall of the mixing shell 102.

[0050] In this embodiment, the base 101 is welded from high-strength alloy steel and has shock-absorbing feet at the bottom to ensure the stability of the equipment under high-speed mixing conditions and effectively counteract the centrifugal force and vibration generated during the mixing process.

[0051] The mixing shell 102 is fixedly installed in the center of the base 101, serving as the main container for the reaction. Its inner wall is precision polished and can be lined with a corrosion-resistant coating as needed to accommodate chemically reactive reactants. A cover plate 103 is slidably positioned at the opening above the mixing shell 102. This cover plate 103 is designed with guide rails and a sealing locking mechanism, enabling quick opening and closing for easy cleaning and maintenance, while also ensuring the airtightness of the reaction system through multiple sealing rings when closed, preventing solvent evaporation or the entry of external impurities.

[0052] The feeding structure 104 is integrated on the top of the cover plate 103 and includes a metering pump, a feed funnel, and an anti-backflow valve. This structure can precisely control the feeding ratio and rate of double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole, realizing automated continuous or batch feeding and reducing human operation errors.

[0053] To address the high viscosity and tendency of reactants to agglomeration, the mixing assembly employs a dual-drive design of "central dispersion + near-wall scraping": The dispersion structure 105 is rotatably positioned on the central axis of the mixing shell 102, typically consisting of a high-speed shear emulsifying head or a multi-layer turbine impeller, driven by a top servo motor. In the initial stage of the reaction, the powerful shear force generated by the high rotation speed rapidly breaks down and uniformly disperses the double-ended epoxy-terminated polysiloxane (high molecular weight prepolymer) and 3,6-diamino-N-alkylcarbazole (functional monomer), breaking down the interfacial tension between the two phases, promoting effective intermolecular collisions and chemical bonding, and preventing side reactions caused by excessively high local concentrations.

[0054] The wall-scraping structure 106 is coaxially disposed inside the mixing shell 102, closely adhering to the inner wall of the shell. Its end is equipped with a flexible, wear-resistant scraper (such as made of polytetrafluoroethylene). Given the rapid viscosity change of the reaction mixture during heating, it easily adheres to the cooler inner wall of the shell, forming a "dead zone." The wall-scraping structure 106 can scrape away the material adhering to the wall of the mixing shell 102 in real time, forcing it back to the central high-temperature mixing zone. This not only improves heat transfer efficiency and avoids localized overheating and coking, but also ensures the consistency of reactant conversion.

[0055] In actual operation, a measured amount of double-ended epoxy-capped polysiloxane and 3,6-diamino-N-alkylcarbazole are first injected into the mixing shell 102 via the feeding structure 104. Then, the cover plate 103 is closed and locked, and the temperature control component is activated for preheating. Next, the mixing component is activated, and the dispersion structure 105 rotates at high speed to achieve microscopic homogenization of the materials. Simultaneously, the wall scraping structure 106 operates at low speed to remove adhering substances from the wall surface, forming a macroscopic circulation throughout the entire reactor without dead zones. The entire process is completed under strict temperature control, ultimately yielding a high-performance modified polysiloxane product.

[0056] The dispersion structure 105 includes a dispersion disk 107, a rotating rod 108, and a rotating motor 109. The rotating rod 108 is rotatably mounted on the cover plate 103. The dispersion disk 107 is fixedly connected to the rotating rod 108 and is located inside the rotating rod 108. The output end of the rotating motor 109 is connected to the rotating rod 108.

[0057] The rotating motor 109 is a servo motor or an explosion-proof asynchronous motor with variable frequency speed control, and is mounted on the motor bracket on the top of the cover plate 103. Its output shaft passes through the sealed bearing seat on the cover plate 103 and is rigidly connected to the top of the rotating rod 108 below via a coupling or direct connection. The torque and speed of the motor can be precisely adjusted according to the reaction stage (such as low-speed mixing in the early stage of feeding, strong shearing in the middle stage of reaction, and homogenization and heat preservation in the later stage).

[0058] The rotating rod 108 is vertically inserted, with its upper end firmly connected to the output end of the rotating motor 109, and its lower end extending below the reaction liquid surface inside the mixing shell 102.

[0059] The rotating rod 108 achieves "rotation setting" through a dynamic sealing assembly (such as a mechanical seal or magnetic coupler) set at the center of the cover plate 103. This ensures the high-speed rotational freedom of the shaft while strictly preventing the leakage of reaction gas or the entry of outside air, thus ensuring the inert environment of the reaction system.

[0060] The dispersing disk 107 rotates synchronously with the rotating rod 108. The dispersing disk 107 is located at the end of the rotating rod 108 or within a specific height range, and its diameter is slightly smaller than the inner diameter of the mixing shell 102, leaving a reasonable shear gap. The surface of the dispersing disk 107 can be designed with radial toothed blades, turbine blades, or a porous screen structure. This design can generate strong radial and axial flow during rotation, forming a high shear force field.

[0061] When the rotating motor 109 starts, the power is transmitted to the dispersing disk 107 via the rotating rod 108, triggering the following physical process: The high-speed rotation of the dispersion disk 107 (linear velocity up to several meters per second) generates a huge velocity gradient between the disk edge and the inner wall of the mixing shell 102, or between the disk blades. This high shear force can instantly tear large clumps of double-ended epoxy-capped polysiloxane into micron- or even nano-sized droplets. The geometry of the dispersion disk 107 generates a powerful pumping effect during rotation, driving the liquid inside the reactor to form a violent up-and-down turbulent circulation. This allows denser or easily settling 3,6-diamino-N-alkylcarbazole particles to be rapidly suspended and uniformly distributed within the polysiloxane mass, eliminating the concentration gradient. Under turbulent conditions, the contact area between the two reactants increases exponentially, significantly reducing the resistance to the diffusion-controlled step, thereby accelerating the ring-opening addition reaction between the epoxy group and the amino group, improving the reaction rate and product uniformity.

[0062] The wall-scraping structure 106 includes a support ring 110, a rotating sleeve 111, a support rod 112, a wall-scraping rod 113, and a driver 114. The support ring 110 is fixed to the cover plate 103. The rotating sleeve 111 is rotatably connected to the support ring 110 and is located on one side of the support ring 110. The support rod 112 is fixed to the rotating sleeve 111. The wall-scraping rod 113 is disposed on the support rod 112 and contacts the inner wall of the mixing shell 102. The driver 114 is used to drive the rotating sleeve 111 to rotate.

[0063] The support ring 110 serves as the mounting reference for the entire scraper assembly, and is rigidly fixed to the lower surface of the cover plate 103. Its central hole is precision-machined and contains a high-precision bearing or wear-resistant bushing to provide stable radial support and axial positioning for the rotating parts, ensuring the coaxiality of the rotation center.

[0064] The rotating sleeve 111 is fitted inside the support ring 110 and is rotatably connected to the support ring 110 via bearings. The rotating sleeve 111 is not only a force transmission medium but also a mounting platform for the wall scraping actuator, and its rotational motion directly determines the revolution trajectory of the wall scraping rod 113.

[0065] One end of the support rod 112 is firmly welded or fixed to the rotating sleeve 111 via a flange, and the other end extends toward the inner wall of the mixing shell 102. The support rod 112 is designed to have sufficient bending stiffness to withstand the resistance torque during the scraping process, and its length is precisely calculated to ensure that the scraping rod 113 at the end can accurately reach the inner wall area of ​​the mixing shell 102.

[0066] The wall scraping rod 113 includes a wall scraping rod body 115, a sliding rod 116 and a spring 117. The sliding rod 116 is slidably disposed on the support rod 112, and the spring 117 is disposed between the sliding rod 116 and the support rod 112. The wall scraping rod body 115 is fixed to the sliding rod 116.

[0067] The scraper rod body 115 is the component that directly contacts the inner wall of the mixing shell 102. It is typically made of a corrosion-resistant, wear-resistant material with a certain degree of flexibility (such as reinforced polytetrafluoroethylene, polyurethane, or a rubber-coated metal skeleton). Its shape is designed to be arc-shaped or knife-edged to maximize the fit to the curvature of the vessel wall.

[0068] The scraper rod body 115 is not rigidly fixed to the end of the support rod 112, but is fixed to the sliding rod 116. The sliding rod 116 can slide along the axial or radial direction of the support rod 112, forming a movable connection. This design allows the scraper rod body 115 to be displaced relative to the support rod 112 within a certain range.

[0069] Spring 117 is disposed between sliding rod 116 and support rod 112 (typically compressed within the cavity formed by the two or sleeved on guide post). The preload of spring 117 is carefully calculated to provide a constant thrust that continuously points towards the inner wall of mixing shell 102.

[0070] Working principle: When the scraper rod body 115 encounters an uneven vessel wall or a thickened area of ​​adhering material, the reaction force of the material pushes the scraper rod body 115 to compress the spring 117, causing the sliding rod 116 to retract, thus avoiding hard collisions that could damage the equipment. When the adhering material is scraped off or the vessel wall becomes smooth again, the spring 117 releases its elasticity, pushing the scraper rod body 115 to re-adhere tightly to the vessel wall. This adaptive compensation mechanism ensures consistent scraping performance throughout the process and effectively prevents "false scraping."

[0071] The driver 114 includes a drive motor 118, a drive gear 119, and a driven gear ring 120. The driven gear ring 120 is fixed to the rotating sleeve 111. The drive gear 119 meshes with the driven gear ring 120. The output end of the drive motor 118 is connected to the drive gear 119.

[0072] To achieve stable, low-speed, high-torque rotation of the scraper structure 106, this solution employs a closed gear transmission system: The driven gear ring 120, as a ring gear, has its inner or outer ring securely fixed to the outer circumference of the rotating sleeve 111 and rotates synchronously with the rotating sleeve 111. The module and number of teeth of the gear ring are optimized to match the required reduction ratio and output torque. The drive gear 119 meshes precisely with the driven gear ring 120, transmitting power to the gear ring. The drive gear 119 is mounted on the output shaft of the drive motor 118, or connected via a short shaft. The drive motor 118 is typically a low-speed, high-torque motor or a standard motor equipped with a gear reducer. Its output directly drives the drive gear 119 to rotate.

[0073] Compared to belt or chain drives, gear drives have the advantages of no slippage, constant transmission ratio, compact structure and easy sealing, making them particularly suitable for use in environments with high hygiene and safety requirements, such as reaction vessels.

[0074] In actual operation, the drive motor 118 drives the gear set, causing the scraping structure 106 to begin revolving around the reactor wall at a relatively low speed (e.g., 10-30 rpm). Under the force of the spring 117, the scraping rod body 115 automatically presses against the inner wall of the mixing shell 102, maintaining tight contact regardless of any slight ellipticity or weld protrusions in the reactor wall. As the rotating sleeve 111 rotates, the scraping rod 113 continuously scrapes off the high-viscosity polysiloxane-carbazole mixture adhering to the reactor wall and pushes it into the strong shear zone in the center of the reactor (dominated by the dispersion structure 105). Since the jacket heating / cooling of the reactor is mainly carried out through the reactor wall, the scraping action continuously renews the material layer at the wall surface, eliminating the thermal resistance of the boundary layer, significantly improving heat transfer efficiency, and preventing the material from decomposing due to local overheating or solidifying due to undercooling.

[0075] The temperature control assembly includes a spiral flow guide jacket 121, a heater 122, and a temperature sensor 123. The spiral flow guide jacket 121 is disposed on the outside of the mixing shell 102. The heater 122 is connected to the spiral flow guide jacket 121. The temperature sensor 123 is disposed inside the mixing shell 102 and is used to obtain the reaction temperature and control the heating power of the heater 122.

[0076] The spiral guide jacket 121 tightly encloses the outer wall of the mixing shell 102. It is not a simple double-layered cavity, but rather a semi-tube or full-jacket structure with continuously welded spiral guide plates inside. The spiral guide plates force the heat transfer medium (such as heat transfer oil, steam, or cooling water) to flow at high speed along a spiral trajectory within the jacket. This design greatly increases the flow velocity and turbulence (Reynolds number) of the medium, effectively disrupting the laminar boundary layer and significantly improving the convective heat transfer coefficient on the outer side of the shell.

[0077] The heater 122 forms a closed loop with the inlet and outlet of the spiral guide jacket 121 via pipelines. In practical engineering, it usually refers to a temperature control unit with bidirectional adjustment capability. During the reaction initiation stage, it acts as the heater 122 to provide high-temperature heat transfer oil to quickly raise the reactor temperature to the reaction starting point; during the violently exothermic reaction stage, it switches to cooling mode (or connects to an external chiller unit in series) to quickly remove the reaction heat and maintain a constant temperature.

[0078] Temperature sensor 123 is directly inserted into the reaction liquid phase inside mixing shell 102, typically located in the strong convection region generated by dispersion structure 105 or in the lower middle part of the reactor. This ensures that the collected temperature data is the most representative and reflects the true average temperature of the material in real time, rather than simply monitoring the wall temperature. An industrial-grade Pt100 platinum resistance thermometer or a high-precision thermocouple is used, equipped with an explosion-proof sheath, providing millisecond-level response speed and ±0.1℃ measurement accuracy, enabling it to sensitively capture minute temperature fluctuations during the reaction process.

[0079] This system constructs a real-time feedback control loop based on the PID (Proportional-Integral-Derivative) algorithm: Temperature sensor 123 monitors the instantaneous temperature of the mixture of double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole inside the mixing shell 102 in real time, and converts the analog signal into a digital signal and transmits it to the central controller (PLC or DCS). The controller compares the measured temperature with the preset process target temperature curve (such as the heating section, isothermal section, and cooling section) and calculates the temperature deviation value and its rate of change.

[0080] When the temperature is low, the controller outputs a command to increase the power of the heater 122 or increase the flow rate of the heat medium, and uses the spiral guide jacket 121 to quickly transfer heat into the vessel.

[0081] When the reaction begins to release heat intensely, the controller immediately reduces the heating power or even cuts off the heat source and starts the circulation of the cooling medium. The spiral guide jacket 121 then transforms into a high-efficiency heat dissipation channel, rapidly carrying away the heat of the reaction.

[0082] By utilizing the differential term in the PID algorithm to predict temperature change trends and adjust the heating power in advance, temperature overshoot and oscillation are effectively suppressed, achieving precise temperature control with "zero overshoot." The heater 122 dynamically adjusts its output based on received instructions, thereby changing the temperature or flow rate of the medium flowing through the spiral guide jacket 121, ultimately stabilizing the reaction temperature within the set range. As the reaction proceeds, the viscosity of the polysiloxane system increases sharply, and internal heat conduction deteriorates. The high-strength external heat exchange capacity of the spiral guide jacket 121 compensates for the insufficient internal heat transfer, preventing stratification due to "external cold and internal heat."

[0083] The reaction of 3,6-diamino-N-alkylcarbazole with epoxy groups is exothermic and concentrated; if the heat is not removed in time, rapid polymerization can easily occur. The rapid response mechanism of this system can intervene instantly at the initial stage of a temperature spike, bringing the reaction back to a controllable range by increasing the cooling force, thus ensuring production safety.

[0084] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A superhydrophobic nanomaterial for protection, characterized in that, By weight, it comprises the following components: 100 parts of N-alkylcarbazole polysiloxane copolymer, 10-70 parts of isocyanate-modified silica, 3.2-4.7 parts of polyphenyl polymethylene polyisocyanate, 5-15 parts of fluorinated modified nanoparticles, 5-20 parts of mesoporous silica, and 3-8 parts of silane coupling agent.

2. The superhydrophobic nanoprotective material as described in claim 1, characterized in that, The N-alkylcarbazole polysiloxane copolymer has a rigid and stable carbazole structure in its molecular backbone, and its thermal decomposition temperature is not lower than 300℃; the isocyanate-modified silica has a particle size range of 20-100nm, and it forms a micro-nano protrusion structure in the polysiloxane body; the fluorinated modified nanoparticles are silica or silicon carbide particles grafted with fluorosilane, with a contact angle greater than 150° and a roll-off angle less than 10°.

3. A method for preparing a superhydrophobic nanomaterial, used to prepare the superhydrophobic nanomaterial according to any one of claims 1-2, characterized in that, include: A double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole were mixed in a reactor at a mass ratio of 100:(6.5-9.2) and reacted at 55-80°C for 12-18 hours to obtain a copolymer. Nanoparticles were mixed with fluorosilane at a mass ratio of 1:0.5-1.0 and fluorinated under acidic conditions to obtain fluorinated modified nanoparticles. The copolymer was mixed with isocyanate-modified silica, polyphenyl polymethylene polyisocyanate, the fluorinated modified nanoparticles, mesoporous silica and silane coupling agent, and dispersed evenly to obtain a superhydrophobic nanoprotective material.

4. The preparation method of the superhydrophobic nanoprotective material as described in claim 3, characterized in that, The fluorosilane is 1H,1H,2H,2H-perfluorodecyltriethoxysilane, the reaction temperature is 60-80℃, and the reaction time is 4-8 hours.

5. The method for preparing a superhydrophobic nanoprotective material as described in claim 4, characterized in that, The reactor includes a support assembly, a mixing assembly, and a temperature control assembly; The support assembly includes a base, a mixing shell, a cover plate, and a feeding structure. The mixing shell is fixed on the base, the cover plate is slidably disposed above the mixing shell, and the feeding structure is disposed on the cover plate. The mixing assembly includes a dispersion structure and a wall scraping structure. The dispersion structure is rotatably disposed within the mixing shell for dispersing double-ended epoxy-terminated polysiloxane and 3,6-diamino-N-alkylcarbazole. The wall scraping structure is rotatably disposed within the mixing shell for scraping the mixture adhering to the wall of the mixing shell.

6. The method for preparing a superhydrophobic nanoprotective material as described in claim 5, characterized in that, The dispersing structure includes a dispersing disk, a rotating rod, and a rotating motor. The rotating rod is rotatably mounted on the cover plate. The dispersing disk is fixedly connected to the rotating rod and located inside the rotating rod. The output end of the rotating motor is connected to the rotating rod.

7. The method for preparing a superhydrophobic nanoprotective material as described in claim 6, characterized in that, The wall scraping structure includes a support ring, a rotating sleeve, a support rod, a wall scraping rod, and a driver. The support ring is fixed to the cover plate. The rotating sleeve is rotatably connected to the support ring and is located on one side of the support ring. The support rod is fixed to the rotating sleeve. The wall scraping rod is disposed on the support rod and contacts the inner wall of the mixing shell. The driver is used to drive the rotating sleeve to rotate.

8. The method for preparing a superhydrophobic nanoprotective material as described in claim 7, characterized in that, The wall scraping rod includes a wall scraping rod body, a sliding rod, and a spring. The sliding rod is slidably mounted on the support rod, and the spring is disposed between the sliding rod and the support rod. The wall scraping rod body is fixed to the sliding rod.

9. The method for preparing a superhydrophobic nanoprotective material as described in claim 8, characterized in that, The driver includes a drive motor, a drive gear, and a driven gear ring. The driven gear ring is fixed to the rotating sleeve. The drive gear meshes with the driven gear ring. The output end of the drive motor is connected to the drive gear.

10. The method for preparing a superhydrophobic nanoprotective material as described in claim 9, characterized in that, The temperature control assembly includes a spiral flow guide jacket, a heater, and a temperature sensor. The spiral flow guide jacket is disposed on the outside of the mixing shell, the heater is connected to the spiral flow guide jacket, and the temperature sensor is disposed inside the mixing shell to obtain the reaction temperature and control the heating power of the heater.

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