A pure titanium material, a preparation method and application thereof
By forming a ZnO/TiO2 coating on the surface of pure titanium material and setting up interdigital electrodes, the problems of high cost and complex operation of existing ammonia detection methods are solved, and high-sensitivity and selective ammonia detection is achieved.
Patent Information
- Application Number
- CN202211338505.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-28
- Publication Date
- 2025-10-14
- Estimated Expiration
- 2042-10-28
AI Technical Summary
Existing ammonia detection methods are costly, complex to operate, and unsuitable for real-time detection, which limits their large-scale application.
A coating is formed on the surface of pure titanium material by micro-arc oxidation in an electrolyte of sodium silicate and zinc acetate, and interdigital electrodes are set to detect ammonia using the oxygen adsorption-desorption principle to form a ZnO/TiO2 coating.
It achieves high sensitivity and selective detection of ammonia, can detect ammonia effectively, in real time and simply, and reduces detection costs.
Smart Images
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of coating materials, in particular to a pure titanium material and a preparation method and application thereof. BACKGROUND
[0002] Ammonia is a colorless, water-soluble gas with a strong irritating odor, widely used in chemical industry, environmental remediation, agriculture, food processing and medical diagnosis. Ammonia has a strong irritating effect on the respiratory tract, eyes and skin. Even if the concentration is very low (higher than the threshold of 25 ppm in the air), long-term exposure to ammonia can cause harmful effects on the respiratory system, skin and eyes of the human body. At the same time, exposure to very high concentrations of ammonia can cause lung damage and even death. Therefore, ammonia must be reliably and effectively detected to reduce its harm to human health and safety.
[0003] At present, the conventional method for detecting ammonia has established ammonia detection methods based on electrochemistry, high-performance liquid chromatography, gas chromatography, spectrophotometry, polarography and fluorescence. Although these methods are widely used, due to high cost and complex operation, especially not suitable for real-time detection, their large-scale application is still limited. SUMMARY
[0004] Therefore, the purpose of the present application is to provide a pure titanium material that can be used for ammonia detection and has high sensitivity to ammonia.
[0005] Another purpose of the present application is to provide a preparation method of the above pure titanium material and its application in detecting ammonia and preparing ammonia detection products.
[0006] In order to solve the above technical problems or at least partially solve the above technical problems, the present application provides a method for solving the above technical problems or at least partially solving the above technical problems, and provides an ammonia material, which has a coating layer on the surface of a pure titanium material, the coating layer being formed by micro-arc oxidation of an electrolyte of sodium silicate and zinc acetate, and an electrode with a connecting wire being arranged on the coating layer.
[0007] In some embodiments of the present application, the pure titanium material contains Ti≥99%; in other embodiments of the present application, the pure titanium material is selected from TA1-TA4 industrial pure titanium, more specifically TA1 industrial pure titanium, and the elemental composition (mass fraction) of the TA1 industrial pure titanium is as follows: Fe 0.2%, C 0.08%, N 0.03%, H 0.015%, O 0.18%, Si 0.1%, Ti≥99.095%.
[0008] In some embodiments of the present application, the electrode is an interdigital electrode, and the wire is a conductive metal wire, such as a copper wire.
[0009] In some embodiments of the present application, the concentration of sodium silicate in the electrolyte is 5-8 g / L, and the concentration of zinc acetate is 1.5-2.5 g / L. In other embodiments of the present application, the concentration of sodium silicate in the electrolyte is 5 g / L, 6 g / L, 7 g / L or 8 g / L, and the concentration of zinc acetate is 1.5 g / L, 2.0 g / L or 2.5 g / L.
[0010] Meanwhile, the present application also provides a method for preparing the pure titanium material, comprising:
[0011] Step 1, the pure titanium material is pretreated by polishing, oil removal and cleaning;
[0012] Step 2, the pretreated pure titanium material is used as the positive electrode, and micro-arc oxidation is performed in the electrolyte of sodium silicate and zinc acetate to form a coating;
[0013] Step 3, an ion sputtering process is used to form an electrode on the surface of the coating, and then a wire is connected to the electrode.
[0014] In some embodiments of the present application, the micro-arc oxidation time can be selected according to the actual situation. In some embodiments of the present application, the micro-arc oxidation time is 4-6 min, and in other embodiments of the present application, the micro-arc oxidation time is 4 min, 5 min or 6 min.
[0015] In some embodiments of the present application, Step 1 is:
[0016] The pure titanium material is polished step by step, cleaned by ultrasonic wave using acetone, anhydrous ethanol and water, and then oil is removed and cleaned by using an alkaline oil removal liquid. The step-by-step polishing is performed using silicon carbide sandpaper with increasing label, and the polishing degree is to the extent that the surface is bright without obvious scratches and the lines are consistent. The alkaline oil removal liquid is sodium hydroxide, which can be selected as a 10% sodium hydroxide solution.
[0017] In order to make the prepared coating have more uniform thickness, higher porosity and sub-micron pores, which are beneficial to ammonia detection, in some embodiments of the present application, the micro-arc oxidation is performed in a constant current mode. In other embodiments of the present application, in the constant current mode, the forward current is preset to 2-8 A, which can be selected as 4 A, the reverse current is preset to 1-5 A, which can be selected as 3 A, the pulse frequency is fixed to 0.1-0.3 Hz, which can be selected as 0.2 Hz, and the duty cycle is set to 70%-90%, which can be selected as 80%. In other embodiments of the present application, in the constant current mode, the rising current mode starts from 0 A and increases by 0.5 A each time until the preset value, and the positive and negative directions are performed synchronously, which can make the prepared micro-arc oxidation coating have better quality and also protect the micro-arc oxidation power supply.
[0018] In some embodiments of the present application, the pure titanium material is used as the positive electrode, other suitable metals such as stainless steel are used as the negative electrode, and the distance between the positive and negative electrodes is controlled to be 10 cm; the temperature of the electrolyte is controlled by an internal and external circulation refrigeration device to maintain 20-35℃.
[0019] In some embodiments of the present application, the electrodes are prepared on the surface coating of the pure titanium material by using a mask to cover the surface of the pure titanium material, and the interdigital electrodes are prepared by an ion sputtering process; the wires are adhered to the electrodes by using conductive silver paste or other conductive materials to form connections.
[0020] In some embodiments of the present application, the ion sputtering process uses a cyclic sputtering method, and the sputtering time and the number of cycles are adjusted according to the required shape of the interdigital electrodes; in some other embodiments of the present application, the sputtering time is 90 s, and the number of cycles is 6 cycles.
[0021] The pure titanium material for detecting ammonia gas in the present application is based on the resistance change of the metal oxide formed on the surface by micro-arc oxidation exposed to air and ammonia gas, and is based on the "oxygen adsorption-desorption" principle of the metal oxide. When the pure titanium material is exposed to air, oxygen will capture free electrons on the surface coating of the pure titanium material to form adsorbed oxygen, resulting in an increase in resistance; when ammonia gas is exposed to the surface coating of the pure titanium material, the ammonia gas will undergo a redox reaction with the adsorbed oxygen to release the captured electrons, and the resistance will decrease, and the equation is as follows:
[0022]
[0023] In the comparison of different electrolytes, the response of the prepared pure titanium material to ammonia gas is detected, and the results show that the resistance ratio sensitivity (K=Ra / Rg) of the electrolyte prepared from sodium silicate and zinc acetate is as high as 18 or more, while the resistance ratio sensitivity of the electrolyte of other several kinds is not more than 11, indicating that the coating on the surface of the pure titanium material has high sensitivity to ammonia gas, and the high resistance ratio sensitivity also reflects good selectivity to ammonia gas.
[0024] In the comparison of common volatile gases such as ethanol, formaldehyde and triethylamine, the response of the pure titanium material to each gas is detected, and the results show that the resistance ratio sensitivity (K=Ra / Rg) of ammonia gas is as high as 18 or more, while the sensitivity values of other several test substances are not more than 5, indicating that the ZnO / TiO2 coating on the surface of the pure titanium material has not only high sensitivity to ammonia gas, but also good selectivity, reducing interference.
[0025] Based on the high sensitivity and selectivity of the pure titanium material to ammonia gas, the present application proposes the use of the pure titanium material in detecting ammonia gas or in preparing products for detecting ammonia gas.
[0026] According to the provided application, the present invention provides a product for detecting ammonia, including a device for recording changes in resistance values and the pure titanium material of the present invention.
[0027] In certain embodiments of the present invention, the device for recording the change in resistance value includes a multimeter and a data processor, wherein the multimeter can be a digital multimeter and the data processor can be a computer device.
[0028] At the same time, the present invention also provides a method for detecting ammonia, wherein the pure titanium material of the present invention is placed in ammonia standard samples of different concentrations, and a standard curve of resistance change data and ammonia concentration is established by a device that records resistance value changes; then, the pure titanium material is placed in a test environment, resistance value change data is obtained, and the ammonia concentration in the test environment is obtained through the standard curve.
[0029] It can be seen from the above technical solution that the present invention uses a composite electrolyte of sodium silicate and zinc acetate to perform micro-arc oxidation to form a ZnO / TiO2 coating on the surface of pure titanium material that can be used for ammonia detection. By setting electrodes and utilizing the oxygen adsorption-desorption principle for detection, it exhibits extremely excellent sensitivity and selectivity for ammonia compared to conventional gases, and thus can effectively, real-time, and simply detect ammonia. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 Shown is the SEM image of the pure titanium material coating in Example 1;
[0031] Figure 2 Shown are the ammonia Ra / Rg results when using different concentrations of zinc acetate and sodium silicate electrolytes;
[0032] Figure 3 The figure shows the composition diagram of the detection system for gas selectivity test;
[0033] Figure 4 Shown is a line graph of ammonia values under different heating temperature conditions;
[0034] Figure 5 Shown is a bar graph of Ra / Rg values for different test gases;
[0035] Figure 6 The figure shows the fitting curve when the pure titanium material of the present invention is used to detect ammonia;
[0036] Figure 7 Shown is the SEM image of the pure titanium material coating prepared by the first group of electrolytes in Example 3;
[0037] Figure 8 Shown are the ammonia Ra / Rg results of the pure titanium material coating prepared using the first group of electrolytes in Example 3;
[0038] Figure 9 Shown is the SEM image of the pure titanium material coating prepared by the second group of electrolytes in Example 3;
[0039] Figure 10 The figure shows the ammonia Ra / Rg results of the pure titanium material coating prepared by the second group of electrolytes in Example 3;
[0040] Figure 11 Shown is a SEM image of the pure titanium material coating prepared by the third group of electrolytes in Example 3;
[0041] Figure 12 Shown are the ammonia Ra / Rg results of the pure titanium material coating prepared using the third group of electrolytes in Example 3. DETAILED DESCRIPTION
[0042] The present invention discloses a pure titanium material and a preparation method and application thereof. Those skilled in the art can refer to the contents of this article and appropriately improve the process parameters to achieve the same. It should be noted in particular that all similar replacements and modifications are obvious to those skilled in the art and are deemed to be included in the present invention. The pure titanium material and the preparation method and application thereof of the present invention have been described through preferred embodiments. Relevant personnel can obviously modify or appropriately change and combine the pure titanium material and the preparation method and application thereof described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention.
[0043] The present invention specifically provides a method for preparing the pure titanium material and the pure titanium material prepared therefrom, comprising:
[0044] 1. Pretreatment of pure titanium substrate
[0045] The pure titanium is cut, polished, and cleaned to obtain clean pure titanium, which is then immersed in a degreasing solution and then ultrasonically cleaned. The pure titanium is taken out, cleaned, and then blown dry to obtain pure titanium after pretreatment.
[0046] 2. Prepare micro-arc oxidation electrolyte
[0047] Dissolve sodium silicate and zinc acetate in deionized water and stir evenly to obtain a micro-arc oxidation electrolyte;
[0048] 3. Micro-arc oxidation
[0049] The pure titanium after surface pretreatment is placed in a micro-arc oxidation electrolyte, wherein the pure titanium is connected to the positive electrode of the power supply as the positive electrode, and the stainless steel electrolytic cell is connected to the negative electrode of the power supply as the cathode; the heat dissipation device is turned on to control the temperature; and the micro-arc oxidation power supply is used to start power supply. Under the conditions of constant current mode, the forward current is preset to 2 to 8A, the negative current is preset to 1 to 5A, the pulse frequency is fixed to 0.1 to 0.3Hz, and the duty cycle is set to 70% to 90%, micro-arc oxidation is performed to obtain pure titanium with a micro-arc oxidation coating on the surface.
[0050] 4. Ion sputtering
[0051] The mask was covered on the surface of the micro-arc oxidation coating and fixed in a vacuum ion sputtering instrument. The sputtering current was controlled constant and the interdigitated electrodes were prepared by a cyclic sputtering method. Each sputtering lasted 90 seconds, and a total of 6 cycles were sputtered.
[0052] 5. Copper wire adhesion
[0053] After sputtering, a multimeter is used to test the conductivity and processing quality of the interdigital electrodes. Then, conductive silver paste is used to stick the copper wires on the interdigital electrodes and dried to ensure good contact of the sensor circuit.
[0054] Unless otherwise specified, the experimental environment and parameter conditions of each group in the specific embodiment tests remain consistent except for the differences explicitly stated.
[0055] The following further describes a pure titanium material provided by the present invention, its preparation method, and its application.
[0056] Example 1: Preparation of pure titanium material for ammonia detection according to the present invention
[0057] 1. Preparation method
[0058] 1. Pretreatment of pure titanium substrate
[0059] The pure titanium substrate was TA1 industrial pure titanium, with the following elemental composition (mass fraction): Fe 0.2%, C 0.08%, N 0.03%, H 0.015%, O 0.18%, Si 0.1%, and Ti ≥ 99.095%. The pure titanium substrate was cut into 25 mm × 25 mm × 2 mm pieces using wire cutting and then polished using silicon carbide sandpaper (400# → 800# → 1000# → 2000#) to achieve a bright surface with no obvious scratches and a consistent texture. The substrate was then ultrasonically cleaned in acetone, anhydrous ethanol, and deionized water for 10 minutes each, and air-dried with a hair dryer to obtain the pretreated pure titanium substrate.
[0060] The bright and clean pure titanium was immersed in a degreasing solution, which was a 10% sodium hydroxide solution at 60°C, and then ultrasonically cleaned for 10 minutes. The pure titanium was taken out and washed with clean water three times, and then dried with a hair dryer to obtain a pure titanium substrate after ultrasonic treatment.
[0061] 2. Prepare micro-arc oxidation electrolyte
[0062] The formula of the micro-arc oxidation electrolyte is 6g / L sodium silicate and 1.5g / L, 2g / L, and 2.5g / L zinc acetate. When preparing, first add 3L of deionized water to the electrolytic cell, then add appropriate amounts of sodium silicate and zinc acetate and fully dissolve them. The micro-arc oxidation electrolyte needs to be replaced every time a micro-arc oxidation operation is performed, and each prepared micro-arc oxidation electrolyte must be used within 24 hours to prevent the micro-arc oxidation electrolyte from deteriorating;
[0063] 3. Micro-arc oxidation
[0064] The pure titanium after surface pretreatment is placed in a micro-arc oxidation electrolyte, wherein the pure titanium is connected to the positive electrode of the power supply as the positive electrode, and the stainless steel electrolytic cell is connected to the negative electrode of the power supply as the cathode. The distance between the positive and negative electrodes is controlled at 10 cm; the refrigeration device is turned on and the temperature is controlled to 30 ° C; the micro-arc oxidation AC pulse power supply is used to start power supply. In the constant current mode, the forward current is preset to 4A, the negative current is preset to 3A, and the rising current method starts from 0A and increases by 0.5A at a time, and the positive and negative directions are carried out simultaneously until the preset value is reached. The pulse frequency is fixed at 0.2Hz, the duty cycle is set to 80%, and the micro-arc oxidation time is 4min. After that, pure titanium with a micro-arc oxidation coating on the surface is obtained;
[0065] 4. Ion sputtering
[0066] The mask was covered on the surface of the micro-arc oxidation coating and fixed in a vacuum ion sputtering instrument. The sputtering current was controlled constant and the interdigitated electrodes were prepared by a cyclic sputtering method. Each sputtering lasted 90 seconds, and a total of 6 cycles were sputtered.
[0067] 5. Copper wire adhesion
[0068] After sputtering, a multimeter was used to test the conductivity and the processing quality of the interdigital electrodes. Then, copper wires were bonded to the interdigital electrodes using conductive silver paste and dried at 80°C for 2 hours to ensure good contact between the sensor circuits.
[0069] The SEM image of the pure titanium material prepared by micro-arc oxidation in this embodiment is shown in FIG. Figure 1 ,Depend on Figure 1 It can be seen that the coating surface is evenly distributed with micron-sized pores, with no visible defects on the surface, high porosity, and large specific surface area, which is conducive to ammonia detection;
[0070] Figure 2The results of ammonia resistance sensitivity (K=Ra / Rg) under different concentrations of zinc acetate are shown in the figure. Figure 2 It can be seen that the sensitivity is relatively high at 1.5-2.5 g / L, all exceeding 11, and the highest is 18.3 at 2 g / L.
[0071] Example 2: Gas selectivity test and fitting curve
[0072] 1. Gas selectivity test
[0073] Reference Figure 3 The detection system shown in the figure is tested. A heating platform is set in a confined space, and the micro-arc oxidation method of the present invention is set on the platform to prepare the pure titanium material. Copper wires are adhered to the interdigital electrodes through conductive silver paste and connected to a multimeter. The multimeter establishes data transmission with a computer.
[0074] A fixed amount of volatile gas solution is injected into the confined space. The solution is quickly volatilized into gas by the heating platform. The gas comes into contact with the sensor to react and generate a signal. The thermometer is used to indicate the temperature of the confined space. The fan is used to quickly exhaust the volatile gas after the test is completed.
[0075] See the results Figures 4-5 ; Figure 4 The results show that under different heating temperature conditions, the Ra / Rg value of ammonia gradually increases and reaches the highest at 150℃; Figure 5 The results showed that at 150°C and 50 ppm concentration, the Ra / Rg value of ammonia was significantly higher than that of several other volatile gases, indicating that it has extremely high sensitivity and strong selectivity for ammonia.
[0076] 2. Fitting curve
[0077] Refer to the above detection system of this embodiment, and start adding ammonia solution of different concentrations (10ppm / 20ppm / 30ppm / 40ppm / 50ppm) after the sensor stabilizes at the preset temperature. Figure 6 The results show that the ZnO / TiO2 coating on the surface of the pure titanium material of the present invention has a good linear relationship (R 2 =0.991), which has great potential in quantitative gas analysis.
[0078] Example 3: Effects of different electrolytes on pure titanium coating and ammonia detection sensitivity The preparation method of Example 1 was referred to, except that the electrolyte composition was adjusted;
[0079] (1) 6g / L sodium silicate + (0.5-3g / L) sodium stannate;
[0080] (2) 6g / L sodium silicate + (0.5-3g / L) sodium tungstate;
[0081] (3) 6g / L sodium silicate + (0.5-3g / L) sodium molybdate;
[0082] The above three groups of electrolytes were tested by SEM and resistance sensitivity (K = Ra / Rg). Figures 7-12 ;
[0083] according to Figure 7 、 Figure 9 and Figure 11 It can be seen that these electrolytes can all produce coatings that meet the requirements, but according to Figure 8 、 Figure 10 and Figure 12 However, it was found that the three electrolytes generally had low resistance ratio sensitivity (K=Ra / Rg) to ammonia. The overall trend was that the sensitivity was higher at 1.5-2.5g / L, and the highest sensitivity was around 10 at 2g / L.
[0084] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A pure titanium material, characterized in that: A coating formed by micro-arc oxidation of an electrolyte containing sodium silicate and zinc acetate is provided on the surface of the pure titanium material, and an electrode with a connecting wire is provided on the coating; the concentration of sodium silicate in the electrolyte is 6 g / L, and the concentration of zinc acetate is 1.5-2 g / L.
2. The pure titanium material according to claim 1, characterized in that: The content of Ti in the pure titanium material is ≥99%.
3. The pure titanium material according to claim 1, characterized in that: The electrodes are interdigitated electrodes.
4. The pure titanium material according to claim 1, characterized in that: The conducting wire is a copper wire.
5. Use of the pure titanium material according to any one of claims 1 to 4 in detecting ammonia or in preparing ammonia detection products.
6. The method for preparing the pure titanium material according to claim 1, characterized in that: include: Step 1: Pre-treatment of pure titanium material by grinding, degreasing and cleaning; Step 2: The pretreated pure titanium material is used as the positive electrode and subjected to micro-arc oxidation in an electrolyte of sodium silicate and zinc acetate to form a coating; Step 3: forming electrodes on the surface of the coating by an ion sputtering process, and then connecting wires to the electrodes.
7. A product for detecting ammonia, characterized in that: The invention comprises a device for recording changes in resistance value and the pure titanium material according to any one of claims 1 to 4.
8. The product according to claim 7, characterized in that: The device for recording the change of resistance value includes a multimeter and a data processor.
9. A method for detecting ammonia, characterized in that: The pure titanium material according to any one of claims 1 to 4 is placed in an ammonia standard sample of different concentrations, and a standard curve of resistance change data and ammonia concentration is established by a device that records the resistance value change; then the pure titanium material is placed in a test environment, the resistance value change data is obtained, and the ammonia concentration in the test environment is obtained through the standard curve.