Method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts

Abstract

The present application relates to a kind of fragile, thin-walled part surface organic contaminant cleaning method, comprising the following steps: the sample to be cleaned is placed into graphite phase carbon nitride particle suspension;The graphite phase carbon nitride particle suspension with the sample to be cleaned placed is carried out dark reaction in lightless condition, so that graphite phase carbon nitride particle is contacted with the sample to be cleaned;The graphite phase carbon nitride particle suspension contacted with the sample to be cleaned is carried out light reaction under light condition, wherein, graphite phase carbon nitride particle suspension produces superoxide radical and hydroxyl radical under light condition, and superoxide radical and hydroxyl radical oxidize the organic contaminant on the surface of the sample to be cleaned into carbon dioxide and water;The residual graphite phase carbon nitride particle on the surface of the sample to be cleaned is cleaned away.The cleaning method will not cause damage to the part, nor will it cause the destruction of the surface microtopography of the part;Graphite phase carbon nitride is simple, inexpensive, environmentally friendly, and has no secondary pollution.

Description

Technical Field

[0001] This invention belongs to the field of precision parts cleaning, specifically relating to a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts. Background Technology

[0002] Thin-walled parts have advantages such as light weight, material saving, and compact structure, and are widely used in industries such as aerospace, medical equipment, machinery, and electronics. Currently, they face not only difficulties in processing technology but also many challenges in the cleaning process. Typically, thin-walled parts made of materials such as glass and ceramics (e.g., the high-precision alumina ceramic gyroscope moving coil skeleton in the aerospace field, with a wall thickness <0.1mm) are prone to breakage and cracking due to their hard and brittle properties using traditional methods (such as ultrasonic cleaning). Thin-walled parts made of materials such as copper and aluminum (e.g., copper spring tube parts in the hydraulic industry, with a wall thickness <0.035mm) are also prone to deformation during ultrasonic cleaning due to their poor rigidity and weak strength. Furthermore, for some thin-walled electronic components with precision etched patterns, immersion and rinsing methods such as acid washing and alkaline washing cannot be used, as they would damage the surface microstructure and micro-organisms, affecting performance.

[0003] In the field of precision machining, traditional cleaning methods include ultrasonic cleaning and chemical reagent (strong acid, strong alkali) cleaning. For example, existing technology 1 discloses a ceramic cleaning method, which includes the following steps:

[0004] (1) Removing adhesive: Ultrasonic cleaning is performed using an organic alkaline detergent heated to 65-65℃; (2) Spraying after removing oil and dirt: Ultrasonic cleaning is performed using a water-based environmentally friendly cleaning agent heated to 60-85℃ with a mass fraction of 3-10%, followed by spraying with room temperature deionized water; (3) Ultrasonic cleaning with pure water: Ultrasonic cleaning is performed using deionized water at 65-65℃; (4) Dehydration and drying: The ceramic product is soaked and heated in deionized water at 70-65℃ and then dehydrated; the product surface is dried using air at a temperature of 100-610℃. However, ceramics are a hard and brittle material, and ultrasonic cleaning may cause damage, affecting product quality and performance; at the same time, this method involves organic alkaline agents and cleaning agents, and subsequent heating and spraying are required, increasing the cleaning process. For example, prior art 2 discloses a ceramic membrane cleaning agent for oilfield produced water, which solves the problem of the lack of effective cleaning methods and formulas for ceramic membranes used in oilfield produced water. The cleaning agent comprises three components: A, B, and C. Component A contains sodium hydroxide and sodium alkylbenzene sulfonate; component B contains sodium hydroxide, sodium alkylbenzene sulfonate, sodium ethylenediaminetetraacetate, triethanolamine, and sodium tripolyphosphate; and component C contains sodium hydroxide, sodium alkylbenzene sulfonate, and hydrogen peroxide. However, this cleaning agent formula is complex, involves many chemicals, and is prone to causing secondary contamination of the samples. Furthermore, the cleaning solution produced after cleaning will pollute the environment, resulting in high treatment costs.

[0005] Therefore, traditional cleaning methods can easily cause damage to parts, surface morphology destruction, secondary pollution, and environmental pollution of cleaning solutions when cleaning organic contaminants from the surfaces of fragile parts made of glass and ceramics. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts. The technical problem to be solved by this invention is achieved through the following technical solution:

[0007] This invention provides a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, comprising the following steps:

[0008] The sample to be cleaned was placed in a suspension of graphite-phase carbon nitride particles;

[0009] A suspension of graphitic carbon nitride particles containing a sample to be cleaned is subjected to a dark reaction under no light conditions, so that the graphitic carbon nitride particles come into contact with the sample to be cleaned.

[0010] A suspension of graphitic carbon nitride particles in contact with the sample to be cleaned is subjected to a photoreaction under light conditions. The graphitic carbon nitride particle suspension generates superoxide radicals and hydroxyl radicals under light conditions. The superoxide radicals and hydroxyl radicals oxidize organic contaminants on the surface of the sample to be cleaned into carbon dioxide and water.

[0011] The residual graphitic carbon nitride particles on the surface of the sample to be cleaned are removed.

[0012] In one embodiment of the present invention, the sample to be cleaned is placed in a suspension of graphitic carbon nitride particles, comprising:

[0013] Weigh out the graphite phase carbon nitride catalyst and place it in a reaction vessel and add water. Sonicate the water and the graphite phase carbon nitride catalyst to dissolve the graphite phase carbon nitride in the pure water to form a suspension of graphite phase carbon nitride particles.

[0014] The sample to be cleaned is placed in the graphite phase carbon nitride particle suspension.

[0015] In one embodiment of the present invention, both the dark reaction and the light reaction are carried out at room temperature and pressure.

[0016] In one embodiment of the present invention, the reaction time of the dark reaction is 30 to 60 minutes.

[0017] In one embodiment of the present invention, the photoluminescence device of the photoreaction uses a xenon lamp with a power of 350W, a wavelength of 380-500nm, and an illuminance of 5,800,000 lux.

[0018] In one embodiment of the present invention, the photoreaction time is 30-60 minutes.

[0019] In one embodiment of the present invention, after cleaning away the residual graphitic carbon nitride particles on the surface of the sample to be cleaned, the method further includes the following steps:

[0020] Observe the state of the water film on the surface of the sample to be cleaned;

[0021] If the water film is continuous, the sample to be cleaned is dried.

[0022] If the water film is broken, the dark reaction process and the light reaction process will be repeated.

[0023] In one embodiment of the present invention, the sample to be cleaned includes parts with a maximum dimension of ≤50mm and a wall thickness of ≤0.1mm in three dimensions.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This invention utilizes graphitic carbon nitride to generate superoxide radicals and hydroxyl radicals under light irradiation. The superoxide radicals and hydroxyl radicals oxidize organic contaminants on the surface of the sample to be cleaned into carbon dioxide and water to clean the sample. This cleaning method is a photocatalytic degradation cleaning scheme, which is essentially a redox reaction under photocatalytic conditions. The cleaning conditions are low and can be carried out under light irradiation without the need for ultrasound or other external energy input. Therefore, the cleaning process involved in this cleaning method belongs to a cleaning method under mild environmental conditions, which will not damage the parts or cause damage to the microstructure of the surface of the parts.

[0026] 2. The cleaning method of the present invention only involves a cleaning photocatalyst, graphitic carbon nitride. Compared with the chemical reagents and cleaning agents used in traditional cleaning processes, graphitic carbon nitride is simple to prepare, inexpensive, environmentally friendly, and does not cause secondary pollution. In addition, the reaction products are harmless substances CO2 and H2O. Therefore, the cleaning process involved in this cleaning method does not cause secondary pollution to the parts or subsequent environmental pollution and high treatment costs of the cleaning solution. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart illustrating a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, as provided in an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram illustrating the principle of a photocatalytic cleaning method provided in an embodiment of the present invention;

[0030] Figure 4 This is a schematic flowchart of another method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, provided in an embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0032] Example 1

[0033] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic flowchart illustrating a method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to an embodiment of the present invention. Figure 2This is a schematic diagram illustrating a process for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, as provided in an embodiment of the present invention. This cleaning method utilizes a photocatalytic reaction to clean organic contaminants, offering a relatively mild cleaning method under environmental conditions. The cleaning method mainly includes three stages: a preparation stage before cleaning; the main cleaning stage, which is divided into dark reaction and light reaction; and a rinsing stage. The specific steps of the cleaning method are as follows:

[0034] S1. Place the sample to be cleaned into a suspension of graphite-phase carbon nitride particles. Specific steps include:

[0035] S11. Weigh the graphite-phase carbon nitride catalyst and place it in a reaction vessel, then add water. Sonicate the water and the graphite-phase carbon nitride catalyst to dissolve the graphite-phase carbon nitride in the pure water, forming a suspension of graphite-phase carbon nitride particles.

[0036] Specifically, weigh an appropriate amount of graphitic carbon nitride g-C3N4 catalyst and place it in a reaction vessel (e.g., a beaker). Measure an appropriate amount of pure water and pour it into the beaker. Sonicate for 20-30 minutes to ensure that the graphitic carbon nitride catalyst is fully and uniformly dissolved in the pure water, thus preparing a graphitic carbon nitride suspension.

[0037] In this embodiment, the mass percentage concentration of the graphitic carbon nitride suspension is 6%. For example, 60g of graphitic carbon nitride g-C3N4 catalyst and 1000g of pure water are weighed and ultrasonically treated to prepare a graphitic carbon nitride suspension with a mass percentage concentration of 6%.

[0038] S12. Place the sample to be cleaned into the graphite phase carbon nitride particle suspension prepared above.

[0039] S2. The graphite phase carbon nitride particle suspension containing the sample to be cleaned is subjected to a dark reaction under light-free conditions, so that the graphite phase carbon nitride particles come into contact with the sample to be cleaned.

[0040] Specifically, the dark reaction process needs to be carried out under light-free conditions, and the dark reaction time can be 30 to 60 minutes to ensure that the g-C3N4 photocatalyst particles in the graphite phase carbon nitride particle suspension are in full contact with and adsorbed by the organic pollutants on the surface of the sample to be cleaned.

[0041] S3. The suspension of graphite-phase carbon nitride particles in contact with the sample to be cleaned is subjected to a photoreaction under light irradiation.

[0042] Specifically, after the dark reaction is completed, the xenon lamp light source is turned on, the current is adjusted to control the appropriate light intensity, and the graphite phase carbon nitride particle suspension that is in contact with the sample to be cleaned is placed under the xenon lamp light source for a certain period of time to complete the photo-reaction process.

[0043] Please see Figure 3 , Figure 3 This is a schematic diagram illustrating the principle of a photocatalytic cleaning method provided in an embodiment of the present invention. Figure 3 In this embodiment, clean and environmentally friendly graphitic carbon nitride is selected as the photocatalyst. Each photocatalyst g-C3N4 particle dispersed in the solution is approximated as a small short-circuited photoelectrochemical cell. When g-C3N4 is irradiated with light, it absorbs light energy. Once the energy exceeds its threshold, the material will be excited, and the photoelectric effect should generate photogenerated electrons (electrons). - ) and holes (h + Under the influence of an electric field, electrons migrate to different positions on the surface of g-C3N4; among them, electrons are captured by dissolved oxygen to form superoxide radicals (·O2). - The cavities adsorb onto the catalyst surface, oxidizing water and hydroxide ions into hydroxyl radicals (·OH). Both of these substances have strong oxidizing properties, thus oxidizing organic contaminants on the part surface into CO2 and H2O, thereby effectively removing contaminants from the part surface. The reaction processes involved in this cleaning process are as follows:

[0044] ① g-C3N4+hv→h + + e - ;

[0045] ② H2O+OH - + h + →·OH;·OH+ Organic Pollutants→CO2+H2O;

[0046] ③ O2 + 2e - →·O2 - ;·O2 - + Organic Pollutants→CO2+H2O.

[0047] Specifically, the photoreaction illumination device uses a xenon lamp with a power of 350W, a wavelength of 380-500nm, and an illuminance of 5,800,000 lux, with a photoreaction time of 30-60 minutes.

[0048] It should be noted that both the dark and light reactions described above can be carried out under normal temperature and pressure conditions, but are not limited to these conditions. In addition to xenon lamps, the light reaction process can also use sunlight or other visible light sources, as long as the light source can excite the graphitic carbon nitride to generate photogenerated electrons and holes.

[0049] S4. Clean away the residual graphitic carbon nitride particles on the surface of the sample to be cleaned.

[0050] Specifically, the sample to be cleaned after the above photodegradation reaction is completed is rinsed with pure water to remove the residual g-C3N4 catalyst particles on the surface of the sample. Then, the thin glass sample is taken out to obtain the clean sample.

[0051] In this embodiment, the sample to be cleaned can be a small, fragile, thin-walled part, specifically including parts with a maximum dimension of ≤50mm and a wall thickness of ≤0.1mm in three dimensions.

[0052] It should be emphasized that the cleaning method involved in this embodiment can be applied to the cleaning of precision parts in multiple fields such as aerospace, electronic components, and hydraulic industry. It has more obvious cleaning technology advantages, especially for small, fragile, thin-walled parts, but it is not limited to the above-mentioned parts. In addition, the organic pollutants involved mainly refer to rust-preventive grease, oil stains, grease, sweat stains, etc. on the surface of raw materials, or organic matter with similar composition and structure. This cleaning method has a more obvious cleaning effect.

[0053] This embodiment utilizes graphitic carbon nitride to generate superoxide radicals and hydroxyl radicals under light irradiation. These radicals oxidize organic contaminants on the surface of the sample to be cleaned into carbon dioxide and water, thus cleaning the sample. This cleaning method is a photocatalytic degradation cleaning scheme, which is essentially a redox reaction under photocatalytic conditions. It has low requirements for cleaning conditions and can be carried out under light irradiation without the need for ultrasound or other external energy input. The cleaning process is a mild environmental cleaning method that will not damage the parts or cause damage to the microstructure of the part surface. Therefore, this cleaning method replaces the traditional ultrasonic cleaning, acid washing, and alkaline washing schemes, overcoming the problem of damage to parts or destruction of the surface microstructure under strong physical or chemical conditions.

[0054] The cleaning method in this embodiment involves only one type of clean photocatalyst, graphitic carbon nitride. Compared with the chemical reagents and cleaning agents used in traditional cleaning processes, graphitic carbon nitride is simple to prepare, inexpensive, environmentally friendly, and does not cause secondary pollution. In addition, the reaction products are harmless substances CO2 and H2O. Therefore, the cleaning process involved in this method does not cause secondary pollution to the parts or subsequent environmental pollution and high treatment costs caused by the cleaning solution.

[0055] Example 2

[0056] Based on Example 1, please refer to Figure 4 , Figure 4 This is a schematic flowchart illustrating another method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, provided by an embodiment of the present invention. The cleaning method specifically includes the following steps:

[0057] S1. Place the sample to be cleaned into a suspension of graphite-phase carbon nitride particles.

[0058] S2. The graphite phase carbon nitride particle suspension containing the sample to be cleaned is subjected to a dark reaction under light-free conditions, so that the graphite phase carbon nitride particles come into contact with the sample to be cleaned.

[0059] S3. The suspension of graphite-phase carbon nitride particles in contact with the sample to be cleaned is subjected to a photoreaction under light irradiation.

[0060] S4. Clean away the residual graphitic carbon nitride particles on the surface of the sample to be cleaned.

[0061] For detailed implementation methods of steps S1-S4, please refer to Example 1. This example will not be repeated here.

[0062] S5. Observe the state of the water film on the surface of the sample to be cleaned; if the water film is continuous, dry the sample to be cleaned; if the water film is broken, repeat the dark reaction process and the light reaction process.

[0063] Specifically, observe the state of the water film on the surface of the sample. If there is no oil, the water will wet the surface well and the water film will be continuous. Then, dry the sample. If it is not cleaned and there is oil on the surface, the water film will be broken. Then repeat steps S1-S4 to continue the dark reaction and light reaction stages until the water film on the surface of the sample to be cleaned is continuous, and a clean sample is obtained.

[0064] The cleaning method in this embodiment is a mild environmental cleaning method that will not damage the parts or cause damage to the microstructure of the parts surface. The photocatalyst graphitic carbon nitride involved is simple and inexpensive to prepare, environmentally friendly, and does not cause secondary pollution. It does not cause secondary pollution to the parts or the problems of subsequent cleaning fluid pollution and high treatment costs.

[0065] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts, characterized in that, Including the following steps: The sample to be cleaned was placed in a suspension of graphite-phase carbon nitride particles; A suspension of graphitic carbon nitride particles containing a sample to be cleaned is subjected to a dark reaction under no light conditions, so that the graphitic carbon nitride particles come into contact with the sample to be cleaned. A suspension of graphitic carbon nitride particles in contact with the sample to be cleaned is subjected to a photoreaction under light conditions. The graphitic carbon nitride particle suspension generates superoxide radicals and hydroxyl radicals under light conditions. The superoxide radicals and hydroxyl radicals oxidize organic contaminants on the surface of the sample to be cleaned into carbon dioxide and water. The residual graphitic carbon nitride particles on the surface of the sample to be cleaned are removed.

2. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, The sample to be cleaned is placed in a suspension of graphitic carbon nitride particles, including: Weigh out the graphite phase carbon nitride catalyst and place it in a reaction vessel and add water. Sonicate the water and the graphite phase carbon nitride catalyst to dissolve the graphite phase carbon nitride in the pure water to form a suspension of graphite phase carbon nitride particles. The sample to be cleaned is placed in the graphite phase carbon nitride particle suspension.

3. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, Both the dark reaction and the light reaction are carried out at room temperature and pressure.

4. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, The reaction time for the dark reaction is 30 to 60 minutes.

5. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, The photoluminescence device used in the photoreaction employs a xenon lamp with a power of 350W, a wavelength of 380-500nm, and an illuminance of 5,800,000 lux.

6. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, The photoreaction time is 30-60 minutes.

7. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, After removing the residual graphitic carbon nitride particles from the surface of the sample to be cleaned, the process further includes the following steps: Observe the state of the water film on the surface of the sample to be cleaned; If the water film is continuous, the sample to be cleaned is dried. If the water film is broken, the dark reaction process and the light reaction process will be repeated.

8. The method for cleaning organic contaminants from the surface of small, fragile, thin-walled parts according to claim 1, characterized in that, The samples to be cleaned include parts with a maximum dimension of ≤50mm and a wall thickness of ≤0.1mm in three dimensions.

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