Aluminum profile surface oxidation treatment process

Abstract

The application discloses an aluminum profile surface oxidation treatment process and relates to the technical field of aluminum material surface treatment. The process comprises the following steps: sequentially performing organic solvent degreasing, alkali washing and acid pickling on the aluminum profile, and performing deionized water cleaning after each operation; taking the pretreated aluminum profile as an anode, placing the anode in an electrolyte, and performing anodic oxidation treatment to obtain a functional component-loaded nanoporous aluminum oxide film; immersing the functional component-loaded nanoporous aluminum oxide film in a sealing liquid, performing penetration crosslinking, and realizing directional arrangement of functional groups under a weak electric field; and finally, performing oven curing to obtain an intelligent response type multifunctional composite oxidation film; the sealing liquid contains a bifunctional organosilane sealing agent. The composite oxidation film prepared by the application significantly improves the hardness and wear resistance of the aluminum profile, and endows the aluminum profile with intelligent properties of light response self-cleaning and pH response antibiosis, so that the aluminum profile can adapt to complex and changeable application environments, prolong the service life and reduce the maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of aluminum surface treatment technology, and specifically to an aluminum profile surface oxidation treatment process. Background Technology

[0002] Aluminum and its alloys are widely used in construction, transportation, electronics, and aerospace due to their lightweight, ease of processing, and high electrical and thermal conductivity. However, aluminum is chemically reactive. Although it can naturally form a thin oxide film in the air, this natural oxide film has a loose, uneven structure and poor corrosion resistance, failing to meet the stringent requirements of most industrial applications. Therefore, artificial surface treatment is necessary to improve its overall performance. Anodizing is one of the most widely used and mature aluminum surface protection technologies. This technology uses an aluminum profile as the anode, applying current in a specific electrolyte (such as sulfuric acid, oxalic acid, or chromic acid systems) to generate a dense, controllable porous aluminum oxide (Al2O3) film on its surface. This artificial oxide film not only significantly improves the corrosion resistance, wear resistance, and electrical insulation of aluminum, but also allows for subsequent coloring or sealing treatments, giving products a rich variety of appearances and more durable protective effects.

[0003] Although existing anodizing technologies are quite mature, their inherent limitations are becoming increasingly apparent in the face of growing demands for high performance and intelligent operation. First, oxide films prepared using traditional processes exhibit static and fixed protective properties, unable to actively adapt to changes in the external environment (such as light, temperature, humidity, and pH), demonstrating a significant lack of dynamic environmental adaptability. Second, current processes struggle to precisely and repeatedly control the complex pore structure and gradient distribution of functional materials within the oxide film at the nanometer or micrometer scale, resulting in single-function films that cannot effectively integrate multiple functions such as self-cleaning, antibacterial properties, and self-repair. Finally, when introducing specific functional materials (such as photocatalysts and antibacterial agents) into the oxide film, existing technologies often face the challenge of a mismatch between the in-situ growth or deposition process of the functional materials and the growth rate of the oxide film itself. This contradiction in reaction kinetics leads to uneven distribution of functional components, weak adhesion to the alumina matrix, and even aggregation or deactivation during film formation, ultimately degrading the overall performance of the composite film and failing to achieve the desired results. Summary of the Invention

[0004] The purpose of this invention is to provide a surface oxidation treatment process for aluminum profiles, which solves the problems existing in the background art.

[0005] To solve the above technical problems, the present invention provides a surface oxidation treatment process for aluminum profiles, comprising the following steps:

[0006] Step (1) Pretreatment steps: The aluminum profile is degreased with organic solvent, alkali washed and acid washed to polish in sequence, and deionized water is used for cleaning after each step.

[0007] Step (2) Three-field coupled anodizing step: The pretreated aluminum profile is used as the anode and placed in the electrolyte. A temperature field is constructed by applying ultrasound and an electrochemical field of pulsed superimposed DC current is applied to perform anodizing treatment to obtain a nanoporous alumina film carrying functional components; the electrolyte contains a temperature-sensitive gradient titanium ester precursor.

[0008] Step (3) Intelligent response sealing step: The nanoporous alumina membrane carrying functional components is immersed in the sealing liquid, and cross-linking is carried out through multi-step heating. The functional groups are oriented and arranged under a weak electric field. Finally, the membrane is cured in an oven to obtain an intelligent response multifunctional composite oxide membrane. The sealing liquid contains a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent.

[0009] The preparation steps of the thermosensitive gradient titanium ester precursor include: mixing di(acetylacetonyl)diisopropoxy titanium with anhydrous ethanol in a three-necked flask, heating to 38-42℃ and stirring to dissolve it; slowly adding N,N-dimethylethanolamine to it and carrying out a ligand exchange reaction at 38-42℃ for 0.8-1.2 hours; then slowly adding anhydrous ethanol solution containing chiral ligands, heating to 43-47℃ and stirring for 1.8-2.2 hours; after the reaction is completed, concentrating by rotary evaporation at 48-52℃ under vacuum, and finally allowing it to stand to remove bubbles to obtain the thermosensitive gradient titanium ester precursor;

[0010] The preparation steps of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent include: under nitrogen protection, slowly adding N,N-dimethyloctylamine to an anhydrous toluene solution of 3-glycidoxypropyltrimethoxysilane and refluxing at 78-82℃ for 3.5-4.5 hours; after the reaction, cooling the system to room temperature, then slowly adding perfluorooctanoic acid, controlling the temperature not to exceed 40℃, and continuing to stir the reaction at 28-32℃ for 1.8-2.2 hours; after adding glacial acetic acid as a stabilizer, removing the solvent and unreacted substances by rotary evaporation at 53-57℃ under vacuum to obtain the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent.

[0011] Preferably, in the preparation of the temperature-sensitive gradient titanium ester precursor, the mass fractions of each raw material are: 100 parts of di(acetylacetonyl)diisopropoxytitanium, 20-30 parts of N,N-dimethylethanolamine, 4-6 parts of chiral ligand, and 500-600 parts of anhydrous ethanol.

[0012] Preferably, in the preparation of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, the mass parts of each raw material are: 140-160 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 85-95 parts of N,N-dimethyloctylamine, 210-230 parts of perfluorooctanoic acid, 8-12 parts of glacial acetic acid, and 750-850 parts of anhydrous toluene.

[0013] Preferably, in the three-field coupled anodizing step:

[0014] The electrolyte contains 185-195 g / L of sulfuric acid, 8-12 g / L of aluminum ions, 8-12 g / L of 4-hydroxy-3-methoxybenzenesulfonic acid as an anchoring point, 4-6 g / L of thermosensitive gradient titanium ester precursor, and 0.7-0.9 g / L of polyethylene glycol modified β-cyclodextrin as a phase change buffer.

[0015] The applied ultrasonic frequency is 28-32 kHz;

[0016] The electrochemical field of pulsed superimposed DC current has a base DC voltage that gradually increases from 11-13 volts to 17-19 volts within 25-35 minutes. The duty cycle of the superimposed pulse signal is dynamically adjusted from 30% to 70% based on the film thickness feedback.

[0017] Preferably, in the intelligent response sealing step:

[0018] The sealing solution contains 10-14 g / L of fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, 2-4 g / L of methyltriethoxysilane as a crosslinking agent, and 0.08-0.12% by mass of dibutyltin dilaurate as a catalyst, and the pH value is controlled at 4.7-4.9 through a buffer system;

[0019] Multi-step temperature-in-permeation crosslinking includes:

[0020] Immerse at 28-32℃ for 4-6 minutes for rapid surface sealing; heat to 48-52℃ and maintain for 8-12 minutes for deep penetration crosslinking; apply a weak electric field of 4-6 volts / cm for 4-6 minutes; and cure in an oven at 75-85℃ for 0.8-1.2 hours.

[0021] Preferably, the alkaline washing in the pretreatment step uses sodium hydroxide solution and is carried out at 58-62°C for 1.5-2.5 minutes; the acid washing and brightening uses nitric acid solution and is carried out at room temperature for 0.8-1.2 minutes.

[0022] Preferably, the chiral ligand is (R)-(-)-1,1-bi-2-naphthol.

[0023] It also provides intelligent responsive multifunctional composite oxide film aluminum profiles prepared by aluminum profile surface oxidation treatment process.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Through the three-field coupling control method and the innovative design of functional molecules, the prepared composite oxide film has achieved significant improvement in mechanical properties and greatly enhanced the microhardness of the film layer. This enables the aluminum profile surface to effectively resist physical scratches and wear during daily use, making it especially suitable for occasions with high traffic or complex environments, thereby significantly extending the product's service life and appearance durability.

[0026] 2. The prepared composite oxide film has excellent photoresponsive self-cleaning ability. Its surface is superhydrophobic when there is no light, which can effectively repel liquids and pollutants. When exposed to ultraviolet light, the surface can quickly change to a superhydrophilic state. This unique reversible change characteristic enables the profiles such as building curtain walls used outdoors to achieve self-cleaning by using sunlight and rainwater, which greatly reduces the frequency of manual cleaning and maintenance costs, and has both environmental protection and economic benefits.

[0027] 3. The oxide film possesses intelligent pH-responsive antibacterial properties. Under normal neutral conditions, the film exhibits a mild antibacterial effect, effectively preventing initial microbial adhesion. However, when bacteria aggregate and their metabolic activity causes the local environment to become acidic, the film is intelligently activated, rapidly enhancing the activity of its antibacterial groups, thus achieving a highly efficient and targeted sterilization effect. This "on-demand sterilization" mode not only improves public health safety but also avoids the continued overuse of antibacterial agents. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Comparative Example

[0030] The comparative aluminum profile was prepared using existing technology. Specifically, 6063 aluminum alloy profiles underwent conventional organic solvent degreasing, alkaline washing, and acid washing pre-brightening treatments. Then, a conventional sulfuric acid anodizing process was used, with a sulfuric acid solution of 180 g / L as the electrolyte, oxidizing for 30 minutes at 15 V DC voltage and 18°C. After oxidation, the profiles were sealed with boiling water and immersed in deionized water at 98°C for 40 minutes. The performance test results of the obtained comparative aluminum profiles are shown in Table 1.

[0031] Example 1: This example provides a surface oxidation treatment process for aluminum profiles, characterized by the following steps:

[0032] The alkaline washing in the pretreatment step uses sodium hydroxide solution and is carried out at 60°C for 2 minutes; the acid washing for brightening uses nitric acid solution and is carried out at room temperature for 1 minute.

[0033] The preparation of a thermosensitive gradient titanium ester precursor is characterized by the following mass fractions of raw materials: 100 parts of di(acetylacetonyl)diisopropoxytitanium, 25 parts of N,N-dimethylethanolamine, 5 parts of (R)-(-)-1,1-bi-2-naphthol (as a chiral ligand), and 500 parts of anhydrous ethanol. In the preparation steps, the temperature is raised to 40°C and stirred to dissolve the precursor; after adding N,N-dimethylethanolamine dropwise, a ligand exchange reaction is carried out at 40°C for 1 hour; after adding anhydrous ethanol solution containing the chiral ligand dropwise, the temperature is raised to 45°C and stirred for 2 hours; after the reaction, the precursor is concentrated by rotary evaporation at 50°C under vacuum, and finally allowed to stand to remove bubbles, yielding a brownish-yellow viscous liquid thermosensitive gradient titanium ester precursor with a yield of 91.5% based on di(acetylacetonyl)diisopropoxytitanium.

[0034] The preparation of a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent is characterized by the following mass proportions of raw materials: 150 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 90 parts of N,N-dimethyloctylamine, 220 parts of perfluorooctanoic acid, 10 parts of glacial acetic acid, and 800 parts of anhydrous toluene. In the preparation steps, a reflux reaction is carried out at 80°C for 4 hours; after cooling to room temperature, perfluorooctanoic acid is added dropwise, and the reaction is continued with stirring at 30°C for 2 hours; after adding glacial acetic acid as a stabilizer, the solvent and unreacted substances are removed by rotary evaporation at 55°C under vacuum to obtain a pale yellow oily liquid fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, with a yield of 88.2% based on 3-glycidyl etheroxypropyltrimethoxysilane.

[0035] In the three-field coupled anodic oxidation step, the electrolyte is characterized by comprising 190 g / L sulfuric acid, 10 g / L aluminum ions, 10 g / L 4-hydroxy-3-methoxybenzenesulfonic acid as an anchoring point, 5 g / L thermosensitive gradient titanium ester precursor, and 0.8 g / L polyethylene glycol-modified β-cyclodextrin as a phase change buffer. The applied ultrasonic frequency is 30 kHz. An electrochemical field of pulsed superimposed DC current is used, with the base DC voltage gradually increasing from 12 volts to 18 volts within 30 minutes. The duty cycle of the superimposed pulse signal is dynamically adjusted from 30% to 70% based on film thickness feedback.

[0036] In the intelligent response sealing step, the sealing solution is characterized by containing 12 g / L of a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, 3 g / L of methyltriethoxysilane as a crosslinking agent, and 0.1% by mass of dibutyltin dilaurate as a catalyst, with the pH value controlled at 4.8 through a buffer system. The multi-step temperature-intensity crosslinking includes: rapid surface sealing by immersion at 30°C for 5 minutes; and deep crosslinking by heating to 50°C and holding for 10 minutes. A weak electric field of 5 volts / cm is applied for 5 minutes. The oven curing step is performed at 80°C for 1 hour.

[0037] The intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process in this embodiment exhibits improved microhardness, making it suitable for manufacturing door and window frames or furniture components that need to withstand a certain degree of physical scratching. Its photoresponsive self-cleaning properties allow rainwater to effectively wash away surface stains after exposure to ultraviolet light when the profile is used in building curtain walls, reducing cleaning and maintenance costs. Its pH-responsive antibacterial properties enable the profile to actively release antibacterial capabilities in microenvironments where bacteria accumulate and produce acid, thus improving public health safety when used in scenarios such as hospital handrails and public transportation interiors.

[0038] Example 2: This example provides an aluminum profile surface oxidation treatment process that is basically the same as that in Example 1. The main difference is that the lower limit values ​​of each range of process parameters are selected for verification. The specific scheme is as follows:

[0039] The process includes the following steps:

[0040] The alkaline washing in the pretreatment step uses sodium hydroxide solution and is carried out at 58°C for 2.5 minutes; the acid washing for brightening uses nitric acid solution and is carried out at room temperature for 1.2 minutes.

[0041] The preparation of a thermosensitive gradient titanium ester precursor is characterized by the following mass proportions of raw materials: 100 parts of di(acetylacetonyl)diisopropoxytitanium, 20 parts of N,N-dimethylethanolamine, 4 parts of (R)-(-)-1,1-bi-2-naphthol (as a chiral ligand), and 600 parts of anhydrous ethanol. The preparation steps include heating to 38°C; the ligand exchange reaction time is 1.2 hours; the reaction time with stirring and maintaining the temperature is 2.2 hours; and the rotary evaporation temperature is 48°C.

[0042] The preparation of a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent is characterized by the following mass proportions of raw materials: 140 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 85 parts of N,N-dimethyloctylamine, 210 parts of perfluorooctanoic acid, 8 parts of glacial acetic acid, and 850 parts of anhydrous toluene. In the preparation steps, the reflux reaction time is 4.5 hours; the reaction is stirred for 2.2 hours after the dropwise addition of perfluorooctanoic acid; and the rotary evaporation temperature is 53°C.

[0043] In the three-field coupled anodic oxidation step, the electrolyte is characterized by comprising 185 g / L sulfuric acid, 8 g / L aluminum ions, 8 g / L 4-hydroxy-3-methoxybenzenesulfonic acid, 4 g / L thermosensitive gradient titanium ester precursor, and 0.7 g / L polyethylene glycol-modified β-cyclodextrin. The applied ultrasonic frequency is 28 kHz. The base DC voltage is gradually increased from 11 volts to 17 volts over 35 minutes.

[0044] In the intelligent response sealing step, the sealing solution is characterized by containing 10 g / L of a fluorocarbon / quaternary ammonium bifunctional organosilane sealing agent, 2 g / L of methyltriethoxysilane, and 0.08% by mass of dibutyltin dilaurate, with the pH value controlled at 4.7. The multi-step temperature-intensity crosslinking includes: immersion at 28°C for 6 minutes; heating to 48°C and holding for 12 minutes; a weak electric field strength of 4 V / cm for 6 minutes; and oven curing at 75°C for 1.2 hours.

[0045] The intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process of this embodiment exhibits slightly lower performance indicators than that of Example 1, but still shows significant performance improvement compared to the comparative example. This combination of process parameters, while ensuring core functionality, controls energy consumption (such as voltage and temperature) and the amount of expensive raw materials (such as catalysts and functional precursors), providing an effective surface treatment solution for consumer electronics product casings (such as laptops and tablets) that require a balance between performance and cost.

[0046] Example 3: This example provides an aluminum profile surface oxidation treatment process that is basically the same as that in Example 1. The main difference is that the upper limit of each range of process parameters is selected for verification. The specific scheme is as follows:

[0047] The process includes the following steps:

[0048] The alkaline washing in the pretreatment step uses sodium hydroxide solution and is carried out at 62°C for 1.5 minutes; the acid washing for brightening uses nitric acid solution and is carried out at room temperature for 0.8 minutes.

[0049] The preparation of a thermosensitive gradient titanium ester precursor is characterized by the following mass proportions of raw materials: 100 parts of di(acetylacetonyl)diisopropoxytitanium, 30 parts of N,N-dimethylethanolamine, 6 parts of (R)-(-)-1,1-bi-2-naphthol (as a chiral ligand), and 500 parts of anhydrous ethanol. The preparation steps include heating to 42°C; the ligand exchange reaction time is 0.8 hours; the stirring and holding reaction time is 1.8 hours; and the rotary evaporation temperature is 52°C.

[0050] The preparation of a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent is characterized by the following mass proportions of raw materials: 160 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 95 parts of N,N-dimethyloctylamine, 230 parts of perfluorooctanoic acid, 12 parts of glacial acetic acid, and 750 parts of anhydrous toluene. In the preparation steps, the reflux reaction time is 3.5 hours; the reaction is stirred for 1.8 hours after the dropwise addition of perfluorooctanoic acid; and the rotary evaporation temperature is 57°C.

[0051] In the three-field coupled anodic oxidation step, the electrolyte is characterized by comprising 195 g / L sulfuric acid, 12 g / L aluminum ions, 12 g / L 4-hydroxy-3-methoxybenzenesulfonic acid, 6 g / L thermosensitive gradient titanium ester precursor, and 0.9 g / L polyethylene glycol-modified β-cyclodextrin. The applied ultrasonic frequency is 32 kHz. The base DC voltage is gradually increased from 13 volts to 19 volts over 25 minutes.

[0052] In the intelligent response sealing step, the sealing solution is characterized by containing 14 g / L of a fluorocarbon / quaternary ammonium bifunctional organosilane sealing agent, 4 g / L of methyltriethoxysilane, and 0.12% by mass of dibutyltin dilaurate, with the pH value controlled at 4.9. The multi-step temperature-intensity crosslinking includes: immersion at 32°C for 4 minutes; heating to 52°C and holding for 8 minutes; applying a weak electric field of 6 volts / cm for 4 minutes; and oven curing at 85°C for 0.8 hours.

[0053] The intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process in this embodiment exhibits stable performance. Higher concentrations of functional additives and process parameters (such as voltage and electric field strength) facilitate the formation of the functional film layer in a shorter time, improving production efficiency. This solution is particularly suitable for fields with higher requirements for protective performance and functional response speed, such as ship porthole frames used in marine environments, where its excellent hardness and superhydrophobicity effectively resist salt spray corrosion and wave erosion.

[0054] Example 4: This example provides an aluminum profile surface oxidation treatment process that is basically the same as that in Example 1. The difference lies in selecting the median values ​​of each parameter range for combination verification. The specific scheme is as follows:

[0055] The process parameters for this process are set as follows:

[0056] In the pretreatment steps, alkaline washing is carried out at 61°C for 1.8 minutes, and acid washing and brightening are carried out at room temperature for 0.9 minutes.

[0057] In the preparation of the thermosensitive gradient titanium ester precursor, 26 parts of N,N-dimethylethanolamine and 5.2 parts of chiral ligand were used. The reaction temperature and time were both selected from the middle values ​​of the ranges described above.

[0058] In the preparation of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, 91 parts of N,N-dimethyloctylamine and 222 parts of perfluorooctanoic acid were used. The reaction temperature and time were both selected as the median values ​​within the ranges described above.

[0059] In the three-field coupled anodic oxidation step, the electrolyte contained 192 g / L sulfuric acid, 11 g / L 4-hydroxy-3-methoxybenzenesulfonic acid, and 5.5 g / L thermosensitive gradient titanium ester precursor. The ultrasonic frequency was 31 kHz. The base DC voltage was gradually increased from 12.5 volts to 18.5 volts over 28 minutes.

[0060] In the intelligent response sealing step, the sealing solution contains 13 g / L of fluorocarbon / quaternary ammonium bifunctional organosilane sealing agent and 3.5 g / L of methyltriethoxysilane, with a pH of 4.85. The multi-step temperature-intensity crosslinking process includes: immersion at 31°C for 5.5 minutes, followed by heating to 51°C and holding for 9 minutes. A weak electric field of 5.5 V / cm is applied for 4.5 minutes. The curing temperature is 82°C, and the curing time is 0.9 hours.

[0061] The intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process of this embodiment achieves excellent comprehensive performance close to that of Example 1. This indicates that the process window of the present invention is wide, and high-performance products can still be stably obtained even with fluctuations within a certain range around the central parameter. This stability is crucial for large-scale industrial production, such as when producing interior panels for rail transit vehicles on automated production lines, it can effectively ensure the consistency of performance between different batches of products.

[0062] Example 5: This example provides an aluminum profile surface oxidation treatment process that is basically the same as that in Example 1, except that a different set of parameters is selected for verification. The specific scheme is as follows:

[0063] The process parameters for this process are set as follows:

[0064] The pretreatment steps are the same as in Example 1.

[0065] In the preparation of the thermosensitive gradient titanium ester precursor, 22 parts of N,N-dimethylethanolamine and 4.5 parts of chiral ligand were used.

[0066] In the preparation of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, 88 parts of N,N-dimethyloctylamine and 215 parts of perfluorooctanoic acid were used.

[0067] In the three-field coupled anodic oxidation step, the electrolyte contained 188 g / L of sulfuric acid, 9 g / L of aluminum ions, 9 g / L of 4-hydroxy-3-methoxybenzenesulfonic acid, and 4.5 g / L of a temperature-sensitive gradient titanium ester precursor. The base DC voltage was gradient-increased from 11.5 volts to 17.5 volts over 32 minutes.

[0068] In the intelligent response sealing step, the sealing solution contains 11 g / L of a fluorocarbon / quaternary ammonium bifunctional organosilane sealing agent and 2.5 g / L of a crosslinking agent, with a pH of 4.75. The multi-step temperature-intensity crosslinking process includes: immersion at 29°C for 5.8 minutes, followed by heating to 49°C and holding for 11 minutes. A weak electric field of 4.5 V / cm is applied for 5.5 minutes.

[0069] The intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process in this embodiment demonstrates that even when the concentration of functional materials and process parameters are slightly lower than the central values, products with significant functional characteristics can still be obtained. This solution achieves a good balance between performance and cost, and can be applied to cost-sensitive applications with specific functional requirements, such as decorative panels for high-end home appliances, which require better wear resistance and stain resistance than traditional anodizing while controlling manufacturing costs.

[0070] Performance testing methods

[0071] To verify the performance of the composite oxide film prepared by the process described in this invention, the following standardized tests were performed on the samples of each embodiment and comparative example:

[0072] Microhardness test: According to GB / T4340.1-2009 "Metallic materials Vickers hardness test - Part 1: Test method", the HVS-1000 microhardness tester was used; the applied load was 0.98N (100gf) and the holding time was 15 seconds. Five different locations were randomly selected for measurement for each sample, and the average value of the results was taken.

[0073] Contact angle test: Shanghai Zhongchen JC2000D1 contact angle measuring instrument was used, and the test was conducted in an environment of (25±1)℃ and 50% relative humidity; the test liquid was 5μL of deionized water; the ultraviolet irradiation experiment used a 30W ultraviolet lamp to irradiate the sample at a distance of 15cm for 1 hour; the dark recovery experiment refers to placing the sample after ultraviolet irradiation in a completely light-proof desiccator for 24 hours and then measuring it again.

[0074] Antimicrobial performance test: The test was conducted in accordance with JIS Z2801:2010 "Antibacterial processed products - Test method for antimicrobial properties"; the test strains were Staphylococcus aureus (ATCC6538) and Escherichia coli (ATCC8739); the bacterial solutions were dropped onto the sample surface, covered with a film, and cultured for 24 hours in neutral (pH=7.0) and acidic (pH=5.5, adjusted with lactic acid) environments at (35±1)℃ and humidity>90%; the antimicrobial rate was calculated by plate count method.

[0075] Performance Comparison

[0076] The aluminum profiles obtained in Examples 1-5 and the comparative examples were tested for their core performance indicators, and the results are summarized in Table 1 below.

[0077] Table 1: Comparison of performance test data for each embodiment and comparative example

[0078]

[0079] As can be seen from the data in Table 1, the intelligent responsive multifunctional composite oxide film aluminum profiles prepared in Examples 1-5 of this invention exhibit significantly improved microhardness, photoresponsive self-cleaning performance (manifested as a reversible transition between superhydrophobicity and superhydrophilicity), and pH-responsive antibacterial performance compared to the comparative examples. The parameter combination in Example 1 achieved the optimal overall performance. Although the parameter combinations in Examples 2, 3, 4, and 5 show slightly different performance characteristics, they all demonstrate superior effects far exceeding those of the prior art (comparative examples), proving that the technical solutions disclosed in this invention are effective and feasible within their defined parameter ranges, and can stably achieve the objectives of this invention.

[0080] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A surface oxidation treatment process for aluminum profiles, characterized in that, Includes the following steps: Step (1) Pretreatment steps: The aluminum profile is degreased with organic solvent, alkali washed and acid washed to polish in sequence, and deionized water is used for cleaning after each step. Step (2) Three-field coupled anodizing step: The pretreated aluminum profile is used as the anode and placed in the electrolyte. A temperature field is constructed by applying ultrasound and an electrochemical field of pulsed superimposed DC current is applied to perform anodizing treatment to obtain a nanoporous alumina film carrying functional components. The electrolyte contains a temperature-sensitive gradient titanium ester precursor; Step (3) Intelligent response sealing step: The nanoporous alumina membrane carrying functional components is immersed in the sealing liquid, and cross-linking is carried out through multi-step heating. The functional groups are oriented and arranged under a weak electric field. Finally, the membrane is cured in an oven to obtain an intelligent response multifunctional composite oxide membrane. The sealing liquid contains a fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent. The preparation steps of the temperature-sensitive gradient titanium ester precursor include: mixing di(acetylacetonyl)diisopropoxy titanium with anhydrous ethanol in a three-necked flask, heating to 38-42°C and stirring to dissolve it; slowly adding N,N-dimethylethanolamine to it and carrying out a ligand exchange reaction at 38-42°C for 0.8-1.2 hours; subsequently, slowly adding anhydrous ethanol solution containing chiral ligands, heating to 43-47°C and stirring to maintain the temperature for 1.8-2.2 hours; after the reaction is completed, concentrating the solution by rotary evaporation at 48-52°C under vacuum, and finally allowing it to stand to remove bubbles to obtain the temperature-sensitive gradient titanium ester precursor; The preparation steps of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent include: under nitrogen protection, slowly adding N,N-dimethyloctylamine to an anhydrous toluene solution of 3-glycidoxypropyltrimethoxysilane and refluxing at 78-82°C for 3.5-4.5 hours; after the reaction, cooling the system to room temperature, then slowly adding perfluorooctanoic acid, controlling the temperature not to exceed 40°C, and continuing the reaction by stirring at 28-32°C for 1.8-2.2 hours; after adding glacial acetic acid as a stabilizer, removing the solvent and unreacted substances by rotary evaporation at 53-57°C under vacuum to obtain the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent; The chiral ligand is (R)-(-)-1,1-bi-2-naphthol.

2. The aluminum profile surface oxidation treatment process according to claim 1, characterized in that, In the preparation of the thermosensitive gradient titanium ester precursor, the mass fractions of each raw material are as follows: 100 parts of di(acetylacetonyl)diisopropoxytitanium, 20-30 parts of N,N-dimethylethanolamine, 4-6 parts of chiral ligand, and 500-600 parts of anhydrous ethanol.

3. The aluminum profile surface oxidation treatment process according to claim 1, characterized in that, In the preparation of the fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, the mass parts of each raw material are as follows: 140-160 parts of 3-glycidyl etheroxypropyltrimethoxysilane, 85-95 parts of N,N-dimethyloctylamine, 210-230 parts of perfluorooctanoic acid, 8-12 parts of glacial acetic acid, and 750-850 parts of anhydrous toluene.

4. The aluminum profile surface oxidation treatment process according to claim 1, characterized in that, In the three-field coupled anodic oxidation process: The electrolyte contains 185-195 g / L of sulfuric acid, 8-12 g / L of aluminum ions, 8-12 g / L of 4-hydroxy-3-methoxybenzenesulfonic acid as an anchoring point, 4-6 g / L of thermosensitive gradient titanium ester precursor, and 0.7-0.9 g / L of polyethylene glycol modified β-cyclodextrin as a phase change buffer. The applied ultrasonic frequency is 28-32 kHz; The electrochemical field of pulsed superimposed DC current has a base DC voltage that gradually increases from 11-13 volts to 17-19 volts within 25-35 minutes. The duty cycle of the superimposed pulse signal is dynamically adjusted from 30% to 70% based on the film thickness feedback.

5. The aluminum profile surface oxidation treatment process according to claim 1, characterized in that, In the intelligent response sealing process: The sealing solution contains 10-14 g / L of fluorocarbon / quaternary ammonium salt bifunctional organosilane sealing agent, 2-4 g / L of methyltriethoxysilane as a crosslinking agent, and 0.08-0.12% by mass of dibutyltin dilaurate as a catalyst, and the pH value is controlled at 4.7-4.9 through a buffer system; Multi-step temperature-in-permeation crosslinking includes: Immerse at 28-32°C for 4-6 minutes for rapid surface sealing; heat to 48-52°C and hold for 8-12 minutes for deep penetration crosslinking; apply a weak electric field of 4-6 volts / cm for 4-6 minutes. The oven curing step is carried out at 75-85°C for 0.8-1.2 hours.

6. The aluminum profile surface oxidation treatment process according to claim 1, characterized in that, The alkaline washing in the pretreatment step uses sodium hydroxide solution and is carried out at 58-62°C for 1.5-2.5 minutes; the acid washing for brightening uses nitric acid solution and is carried out at room temperature for 0.8-1.2 minutes.

7. An intelligent responsive multifunctional composite oxide film aluminum profile prepared by the aluminum profile surface oxidation treatment process according to any one of claims 1-6.

Images