Metal-based needle tube and preparation method and application thereof

Abstract

The application provides a metal-based needle tube and a preparation method and application thereof, and relates to the technical field of detection, and aims to solve the technical problem that the sampling needle is made of rigid material and cannot detect the solution property of the sample or reagent at the same time. The preparation method of the metal-based needle tube comprises the following steps: anodizing the needle tube as an anode in an electrolyte, taking a conductive wire as a cathode, arranging the conductive wire in the needle tube, and arranging the conductive wire coaxially with the needle tube; the voltage of anodization is 0.1V-50V, the temperature is 15-80 DEG C, and the time is 1-600 min; coating the wall surface of the needle tube after anodization with a uniform polymer film; the polymer is one of polytetrafluoroethylene, polydimethylsiloxane and polyethylene; and the metal is one of titanium, copper and stainless steel. The needle tube is used for sampling and detecting the concentration, type or pH value of the liquid at the same time.

Description

Technical Field

[0001] This disclosure relates to the field of testing, and in particular to a metal-based needle, its preparation method, and its application. Background Technology

[0002] Sampling needles are widely used in scientific research, diagnostic equipment, and other fields, primarily for collecting reagents or samples to be tested. However, in certain specialized fields, sampling needles need to obtain accurate information on the chemical substances in a sample solution at specific times, locations, and concentrations. Current sampling needle technologies cannot meet this requirement. Summary of the Invention

[0003] The purpose of this invention is to provide a metal-based needle tube, its preparation method, and its application, in order to solve the technical problem that when the sampling needle is made of a rigid material, it is impossible to detect the solution properties of the sample or reagent at the same time as sampling.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing a metal-based syringe, which is used for both sampling and detection of liquid properties, including one or more of the following: concentration, type, or pH value; the syringe preparation method includes:

[0006] The needle tube is used as the anode for anodic oxidation in the electrolyte, and the conductive wire is used as the negative electrode. The conductive wire is disposed in the needle tube and is coaxial with the needle tube.

[0007] The voltage for anodizing is 0.1V to 50V, the temperature is 15℃ to 80℃, and the time is 1min to 600min.

[0008] A uniform polymer film is coated on the wall of the anodized syringe.

[0009] The polymer is one of polytetrafluoroethylene, polydimethylsiloxane, and polyethylene.

[0010] The metal is one of titanium, copper, or stainless steel.

[0011] According to at least one embodiment of the present disclosure, the solute of the electrolyte is one of ammonium fluoride, ammonium chloride, ammonium bromide, sodium chloride, potassium chloride, calcium chloride, copper chloride, ferric chloride, sodium bromide, calcium bromide, potassium bromide, copper bromide, and ferric bromide.

[0012] The solvent of the electrolyte is one or more of water, ethylene glycol, and glycerol.

[0013] According to at least one embodiment of this disclosure, the electrolyte is an ethylene glycol solution of ammonium fluoride, wherein the weight percentage of ammonium fluoride is 0.1% to 0.5%, and the ethylene glycol solution of ammonium fluoride further comprises 1% to 3% water by volume, or...

[0014] The electrolyte is an aqueous solution of sodium chloride, wherein the weight percentage of sodium chloride is 0.1% to 1%.

[0015] According to at least one embodiment of this disclosure, the step of coating the wall surface of the anodized needle with a uniform polymer film includes:

[0016] When the polymer is polytetrafluoroethylene or polyethylene, the anodized needle is vertically immersed in the polymer solution for a length of 5% to 90% of the needle length, repeated 1 to 10 times, and for a duration of 1 to 300 seconds; or...

[0017] When the polymer is polydimethylsiloxane, the inner and outer walls of the syringe are coated with a polydimethylsiloxane solution. The polydimethylsiloxane solution is a mixture of polydimethylsiloxane and a silane coupling agent, and the mass ratio of polydimethylsiloxane to the silane coupling agent is (5-15):1.

[0018] According to at least one embodiment of this disclosure, the step of coating the wall surface of the anodized needle with a uniform polymer film further includes:

[0019] The syringes that have been impregnated or coated with the polymer solution are dried at a temperature of 40°C to 150°C for 1 hour to 24 hours.

[0020] After the syringes impregnated with the polymer solution are dried, a heat treatment is performed at 1°C / min. -1 ~10℃·min -1 The heating rate is increased to 365℃~400℃, held for 5min~120min, and then furnace cooled to below 250℃.

[0021] According to at least one embodiment of this disclosure, the length of the needle is 10 mm to 1000 mm and the inner diameter is 0.1 mm to 10 mm.

[0022] According to at least one embodiment of this disclosure, a pretreatment is further included before the anodizing, the pretreatment being one or more of cleaning the syringe, nitrogen purging and drying;

[0023] The pretreatment also includes cleaning and drying the conductive wire; and / or,

[0024] The process includes a post-treatment following the anodizing, which involves cleaning the syringe in deionized water, purging it with nitrogen, and drying it.

[0025] According to at least one embodiment of this disclosure, the conductive wire is one of metal, alloy, or carbon fiber, and the diameter of the conductive wire is 0.05 mm to 9 mm.

[0026] Compared to existing technologies, the core of this invention lies in applying a polymer coating to a metallic syringe, enabling real-time detection of liquid properties such as concentration, type, and pH value during sampling. The syringe prepared according to the embodiments of this invention provides different voltage values ​​for different liquid concentrations, types, or pH values, thus allowing for real-time and accurate detection of various liquid properties. This makes it suitable for specific fields, such as biomedical testing, which requires not only rigid syringes but also real-time detection of liquid properties during sampling. Currently, no such rigid syringes are available in this field.

[0027] The syringe of this invention uses a metal tube such as titanium, copper, or stainless steel as a substrate. Through anodizing, a nanostructure is formed on the substrate, and a polymer film, such as polytetrafluoroethylene, polydimethylsiloxane, or polyethylene film, can be uniformly coated onto the substrate. The anodizing process involves placing a conductive wire as the negative electrode within the syringe, coaxially aligned, so that both the inner and outer walls of the syringe can be coated with a polymer film. The nanostructure formed under anodizing conditions of 0.1V–50V, 15℃–80℃, and 1min–600min improves the adhesion between the polymer film and the syringe, as well as the uniformity of the polymer film on the syringe wall. Furthermore, the syringe coated with the polymer film allows for real-time and accurate detection of various liquid properties during sampling.

[0028] Another object of the present invention is to provide a metal-based needle tube manufactured by the above-described preparation method, wherein the wall surface of the metal-based needle tube has a polymer film layer, wherein the film layer is one of polytetrafluoroethylene film, polydimethylsiloxane film, and polyethylene film.

[0029] Compared with existing technologies, the metal-based needle tube of the present invention has the following advantages:

[0030] The metal needle tube and the preparation method of the aforementioned needle tube have the same advantages over the prior art, and will not be repeated here.

[0031] Another object of the present invention is to provide an application of a metal-based syringe in detecting the properties of a liquid, said liquid properties including one or more of the following: concentration, type, and pH value.

[0032] Compared with existing technologies, the application of the metal-based needle tube described in this invention has the following advantages:

[0033] The application of the metal needle in detecting liquid properties has the same advantages as the needle preparation method described above compared to the prior art, and will not be repeated here. Attached Figure Description

[0034] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0035] Figure 1 Optical images of needles, where a is a regular needle and b is the needle of Example 1.

[0036] Figure 2 The image shows the surface of the needle after coating in Example 1, where a is an optical image of the coating and b is an SEM image of the coating.

[0037] Figure 3 This is the output voltage of the syringe in Example 1 in salt solutions of different concentrations.

[0038] Figure 4 This refers to the output voltage of the syringe in different types of solutions in Example 1.

[0039] Figure 5 This is a graph showing the change in the length of nanotubes formed on the surface of the needle after anodizing in Example 1.

[0040] Figure 6 This is a graph showing the change in the length of nanotubes formed on the surface of the needle after anodizing in Example 2.

[0041] Figure 7 This is an optical image of the PDMS film coated in Example 4.

[0042] Figure 8 It is the output voltage of the needles prepared in Examples 1-3 in aqueous solution. Detailed Implementation

[0043] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. This disclosure will now be described in detail with reference to the accompanying drawings and embodiments. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0045] This invention provides a method for preparing a metal-based needle. The needle is used for both sampling and liquid property detection, whereby the liquid properties include one or more of the following: concentration, type, or pH value. The needle preparation method includes: anodizing the needle as the anode in an electrolyte, with a conductive wire as the negative electrode, the conductive wire being placed inside the needle and coaxial with the needle; the anodizing voltage being 0.1V to 50V, the temperature being 15℃ to 80℃, and the time being 1min to 600min; and coating the wall of the anodized needle with a uniform polymer film; the polymer being one of polytetrafluoroethylene, polydimethylsiloxane, and polyethylene; and the metal being one of titanium, copper, or stainless steel.

[0046] Please see Figures 3-4 As shown, the metal-based needle prepared by the method of this invention exhibits regular electrical properties in solutions of the same type but different concentrations, or in solutions of different types. The principle behind the electrical properties exhibited in the embodiments of this invention is solid-liquid triboelectric generation, which converts the mechanical energy generated by solid-liquid friction into electrical energy. This principle has not yet been found in the prior art for use in the field of liquid detection with rigid needles. In order to coat the rigid needle with a polymer layer, this invention uses an electrochemical oxidation method to first form a nanostructure on the base tube, thereby coating it with a polymer layer. This polymer layer has high bonding strength and uniformity, and exhibits precise electrical properties for various liquids. The metal needle in this invention can be titanium, copper, or stainless steel, preferably titanium or copper, and preferably titanium; the polymer can be polytetrafluoroethylene (PTFE) or polydimethylsiloxane (PDMS), preferably PTFE.

[0047] The preparation parameters for the above-mentioned anodizing can be a voltage of 1V to 30V, a temperature of 15℃ to 60℃, and a time of 60min to 480min; alternatively, a voltage of 10V to 30V, a temperature of 15℃ to 40℃, and a time of 120min to 360min; or alternatively, a voltage of 15V to 25V, a temperature of 20℃ to 30℃, and a time of 200min to 300min. The voltage for the above-mentioned anodizing can be a constant voltage or a square wave voltage. For example, 10V for 120s and 30V for 20s constitute one cycle; exemplarily, 15V for 100s and 20V for 150s constitute one cycle.

[0048] The solute in the electrolyte for the above-mentioned anodizing is one of ammonium fluoride, ammonium chloride, ammonium bromide, sodium chloride, potassium chloride, calcium chloride, copper chloride, ferric chloride, sodium bromide, calcium bromide, potassium bromide, copper bromide, and ferric bromide. The solvent is one or more of water, ethylene glycol, and glycerol. Optionally, the electrolyte is an ethylene glycol solution containing 0.1% to 0.5% ammonium fluoride by weight, and further contains 1% to 3% water by volume. For example, the ammonium fluoride is a 0.2% to 0.4% ethylene glycol solution containing 1.5% to 2.5% water by volume.

[0049] In the step of coating the wall of the anodized needle with a uniform polymer film, for example, when the polymer is a polymer with strong electronegativity such as polytetrafluoroethylene or polyethylene, the film is coated on the tube wall using the dip-coating method. For example, the anodized needle is vertically immersed in a polytetrafluoroethylene solution or a polyethylene solution, with an immersion length of 5% to 90% of the needle length, 1 to 10 immersions, and an immersion time of 1 to 300 seconds. Alternatively, the immersion length is 30% to 80% of the needle length, 3 to 7 immersions, and 15 to 250 seconds. Still alternatively, the immersion length is 50% to 75% of the needle length, 4 to 6 immersions, and 50 to 150 seconds. After impregnation, the syringe is dried. During drying, the syringe should be placed vertically in the oven to ensure uniform coating. The drying temperature is 40℃~150℃, and the time is 1h~24h. Optionally, the drying temperature is 50℃~120℃, and the time is 2h~15h. Alternatively, the drying temperature is 60℃~100℃, and the time is 4h~12h. Another option is the drying temperature is 70℃~90℃, and the time is 6h~8h. Considering that polytetrafluoroethylene requires high-temperature crystallization to form a film, this embodiment of the invention also includes a heat treatment step. The heat treatment involves placing the dried syringe in a muffle furnace at 1℃·min. -1 ~10℃·min -1 The heating rate is increased to 365℃~400℃, held for 5min~120min, and then furnace cooled to below 250℃; optionally, the heating rate is increased to 3℃·min. -1 ~7℃·min -1 The heating rate is increased to 370℃~390℃, held for 10min~100min, and then furnace cooled to below 150℃; alternatively, the heating rate can be increased to 4℃·min. -1 ~6℃·min -1 The heating rate is increased to 370℃~379℃, held for 15min~85min, and then furnace cooled to below 100℃; alternatively, the heating rate is increased to 4.5℃·min. -1 ~5.5℃·min -1The heating rate is increased to 381℃~385℃, held for 20min~50min, and then furnace cooled to below 25℃. After the above drying and heat treatment steps, the adhesion between the needle and the polymer film is improved, and the uniformity of the film thickness is also improved accordingly.

[0050] For example, when the polymer is polydimethylsiloxane, a polydimethylsiloxane solution is used to coat the inner and outer walls of the syringe. The polydimethylsiloxane solution is a mixture of polydimethylsiloxane and a silane coupling agent, wherein the mass ratio of polydimethylsiloxane to the silane coupling agent is (5-15):1, optionally (8-12):1, or even optionally (9-11):1. After the inner and outer walls of the syringe are uniformly coated, the process also includes drying. During drying, the syringe should be placed vertically in an oven to ensure the uniformity of the coating. The drying temperature is 40℃-150℃, and the time is 1h-24h. Optionally, the drying temperature is 50℃-120℃, and the time is 2h-15h. Alternatively, the drying temperature is 60℃-100℃, and the time is 4h-12h. Optionally, the drying temperature is 70℃-90℃, and the time is 6h-8h. Because polydimethylsiloxane has a high viscosity, its solution can be dried at low temperature to form a film without the need for heat treatment.

[0051] The aforementioned syringes have a length of 10 mm to 1000 mm and an inner diameter of 0.1 mm to 10 mm. Optionally, the length is 30 mm to 500 mm and the inner diameter is 0.5 mm to 5 mm. Alternatively, the length is 40 mm to 300 mm and the inner diameter is 0.7 mm to 3 mm. Also, the length is 60 mm to 100 mm and the inner diameter is 1.5 mm to 2 mm. The length and inner diameter of the syringes are chosen considering the capillary effect on the uniformity of the coating layer on the inner wall of the syringe, as well as the uniformity of the nano- or micro-structures formed on the inner and outer walls of the syringe by anodizing. Using syringes within the above range can improve the accuracy of the electrical properties exhibited by the syringes in the detection solution.

[0052] In some embodiments, to position the cathode conductive wire at the needle tube axis and to address short-circuit issues, the diameter of the cathode conductive wire is smaller than the inner diameter of the needle tube. For example, the diameter of the cathode conductive wire ranges from 0.05 mm to 8 mm. For instance, when the inner diameter of the needle tube is 0.1 mm, the diameter of the conductive wire is 0.05 mm, while when the inner diameter of the needle tube is 10 mm, the diameter of the conductive wire can be 8 mm. It is understood that, without affecting the anodizing effect and without being smaller than the inner diameter of the needle tube, the diameter of the conductive wire can also be 1 mm, 3 mm, 5 mm, 7 mm, or 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm. For example, the material of the cathode conductive wire can be one of metal, alloy, or carbon fiber, such as stainless steel wire. In some embodiments, the specific material is not limited.

[0053] In some embodiments, a pretreatment is included before anodizing. This pretreatment includes one or more of the following: cleaning the needle, purging with nitrogen, and drying. The pretreatment also includes cleaning and drying the conductive wire. Specifically, the needle is ultrasonically cleaned sequentially in a detergent, ethanol, and deionized water. The cleaned titanium tube is then dried with nitrogen and placed in an oven for drying. The conductive wire is ultrasonically cleaned sequentially in ethanol and deionized water, and the cleaned stainless steel wire is then placed in an oven for drying.

[0054] In some embodiments, a post-treatment is included after anodizing, which involves cleaning the needle in deionized water, purging with nitrogen, and drying. Specifically, the anodized needle is ultrasonically cleaned in deionized water, the cleaned needle is dried with nitrogen to remove surface moisture, and then placed in an oven for drying.

[0055] This invention also provides a metal-based needle tube, which is prepared by the above-described preparation method. The metal-based needle tube has a polymer film layer on its wall surface, and the film layer is one of polytetrafluoroethylene film, polydimethylsiloxane film, and polyethylene film.

[0056] This invention also provides an application of a metal-based needle prepared by a certain method in detecting the properties of liquids. The metal-based needle exhibits good electrical signals through solid-liquid triboelectric generation, and can simultaneously perform real-time detection of liquid concentration, identification of liquid type, and detection of liquid pH value.

[0057] The following are examples of several methods for preparing metal-based needles, and representative needles are selected for performance analysis.

[0058] Example 1

[0059] The method for preparing the metal-based needle provided in this embodiment specifically includes:

[0060] (1) A titanium tube with a length of 60 mm and an inner diameter of 1 mm was ultrasonically cleaned in detergent, ethanol and deionized water in sequence for 30 min.

[0061] (2) After cleaning, the titanium tube was dried with nitrogen gas and then placed in an oven to dry. The oven temperature was 60℃ and the drying time was 5 hours.

[0062] (3) The stainless steel wire with a diameter of 0.3 mm was ultrasonically cleaned in ethanol and deionized water in sequence for 10 min. The cleaned stainless steel wire was then placed in an oven to dry at a temperature of 60℃ for 30 min.

[0063] (4) Fix the stainless steel wire in the center of the inside of the titanium tube to ensure that the stainless steel wire coincides with the axis of the titanium tube.

[0064] (5) Connect the titanium tube to the positive terminal of the power supply and the stainless steel wire to the negative terminal of the power supply. Pass the electrolyte (ethylene glycol solution containing 2 vol% water and 0.3 wt% ammonium fluoride) through the power supply. Under the condition of a square wave voltage of 10V for 120s and 30V for 20s as one cycle, the titanium tube is anodized for 4 hours. During the oxidation process, the electrolyte temperature is kept at 25℃±2℃.

[0065] (6) The anodized titanium tube was ultrasonically cleaned in deionized water for 3 minutes;

[0066] (7) After cleaning, the titanium tube is dried with nitrogen gas to remove surface moisture, and then placed in an oven for drying. The oven temperature is 60℃ and the drying time is 3 hours.

[0067] (8) The dried titanium tube is vertically immersed in a polytetrafluoroethylene aqueous dispersion, wherein the polytetrafluoroethylene solid content is 60%, the immersion depth is 30 mm, the number of times is 1, and the immersion time is 5 s.

[0068] (9) Place the impregnated titanium tube vertically into an oven for drying. The oven temperature is 75℃ and the drying time is 30min.

[0069] (10) Place the dried titanium tube into the muffle furnace, raise the temperature of the muffle furnace to 380°C at a rate of 5°C per minute, hold for 15 minutes, and then cool it down to 25°C with the furnace.

[0070] Example 2

[0071] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0072] Replace the titanium tubes in each step of the preparation method with stainless steel tubes.

[0073] Example 3

[0074] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0075] Replace the titanium tubes in each step of the preparation method with copper tubes.

[0076] Example 4

[0077] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0078] In step (8), a polydimethylsiloxane solution is used to coat the wall of the titanium tube by brushing, wherein the mass ratio of polydimethylsiloxane to silane coupling agent is 10:1.

[0079] In step (9), the oven temperature is 50°C and the drying time is 8 hours.

[0080] Step (10) is omitted.

[0081] Example 5

[0082] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0083] In step (5), the electrolyte introduced is a 0.3 wt% ammonium fluoride ethylene glycol solution with a water content of 0.

[0084] Example 6

[0085] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0086] In step (3), the diameter of the stainless steel wire is 0.4 mm.

[0087] In step (5), the power supply is turned on and anodizing is performed under a constant voltage of 50V for 3 hours.

[0088] In step (8), the dried titanium tube is vertically immersed in a polytetrafluoroethylene aqueous dispersion, wherein the polytetrafluoroethylene solid content is 50%, and the immersion is repeated twice, with each immersion lasting 10 seconds.

[0089] Example 7

[0090] The difference between the metal-based needle preparation method provided in this embodiment and that in Embodiment 1 is:

[0091] In step (1), the inner diameter of the titanium tube is 3 mm.

[0092] Please see Figure 1 As shown, in the preparation method of Example 1, after the titanium tube surface is coated with a polytetrafluoroethylene film, the original metallic luster becomes dull. Figure 2 As shown in the optical and microscopic morphology of the polytetrafluoroethylene (PTFE) film, in figure a, it can be seen that the PTFE film is tightly bonded to the titanium tube substrate without cracks or air layers; while in figure b, it can be seen that the surface morphology of the PTFE film is uniform and has a micron-sized structure.

[0093] Please see Figures 3-4 As shown, the syringe prepared in this embodiment of the invention can output different voltages in salt solutions of different concentrations. For example, the input voltage of the syringe decreases proportionally as the NaCl solution concentration increases. It can also be seen that changes in the pH of the solution will produce different output voltages, and this pattern exhibits a certain regularity. Therefore, the syringe prepared in this embodiment of the invention can achieve detection of different concentrations and solutions.

[0094] Please see Figures 5-6 As shown, Example 2 uses a stainless steel tube as the substrate. During the anodizing stage, the morphology of the nanotubes formed on its surface exhibits a larger variation in tube length along the axial direction. In contrast, Example 1 uses a titanium tube as the substrate. During the anodizing stage, the morphology of the nanotubes formed on its surface shows a more stable variation along the axial direction. In other words, the nanotubes prepared in Example 1 are more uniform than those in Example 2. Therefore, the polytetrafluoroethylene (PTFE) coating layer is also more uniform, which is reflected in the output electrical performance as follows: Figure 8 As shown, in deionized water, the output performance of the copper tube prepared in Examples 1-3 is inferior to that of the titanium tube, while the output performance of the stainless steel tube is far inferior to that of the titanium tube. In other words, in terms of detection sensitivity, the titanium tube is greater than the copper tube, and the copper tube is greater than the stainless steel tube. This is because the wetting performance of the stainless steel tube after anodizing is far inferior to that of the titanium tube, resulting in poor adhesion between the polytetrafluoroethylene coating and the stainless steel tube. It can be understood that the output voltage of the copper tube is between that of the titanium tube and the copper tube, and its wetting performance is also between the two.

[0095] Please see Figure 7 As shown, in Example 4, the polydimethylsiloxane was coated by brushing due to its high viscosity. The polydimethylsiloxane only needs to be cured into a film at a low temperature. The uniformity of the film is slightly worse than that of the polytetrafluoroethylene film in Example 1, but it still exhibits the output performance shown in Example 1.

[0096] The electrolyte in Example 5 was an anhydrous ammonium fluoride ethylene glycol solution. The output performance of the final prepared needle was far inferior to that of Example 1. Because the titanium dioxide nanotubes prepared in Example 5 had very smooth walls and were too long compared to those in Example 1, the wetting performance was not as good as that of the needle in Example 1. As a result, the bonding force between the two was poor when the polytetrafluoroethylene coating was applied, leading to poor output electrical performance.

[0097] It should be noted that the syringes prepared in Examples 6-7 all have similar or the same electrical output performance as those in Example 1, and can detect solutions of different types and concentrations with high accuracy.

[0098] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0099] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0100] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. Use of a metal-based needle tube in detecting properties of a liquid, characterized in that, The needle tube is used for sampling and detecting liquid properties, and the liquid properties include one or more of concentration, type or pH value of the liquid; the needle tube is prepared by the following method, comprising: The needle tube is anode oxidized in an electrolyte, and the conductive wire is cathode, the conductive wire is arranged in the needle tube, and the conductive wire is coaxial with the needle tube; The anode oxidation voltage is 0.1V-50V, the temperature is 15℃-80℃, and the time is 1min-600min; The wall surface of the needle tube after anode oxidation is coated with a layer of polymer film; The polymer is one of polytetrafluoroethylene, polydimethylsiloxane and polyethylene; The metal is titanium; The electrolyte is an ammonium fluoride ethylene glycol solution, the weight percentage of the ammonium fluoride is 0.3%, and the ammonium fluoride ethylene glycol solution also has 2% water by volume.

2. Use according to claim 1, characterized in that, The step of coating the wall surface of the needle tube after anode oxidation with a layer of uniform polymer film comprises: When the polymer is polytetrafluoroethylene or polyethylene, the needle tube after anode oxidation is vertically immersed in a polymer solution, the immersion length is 5%-90% of the length of the needle tube, the immersion frequency is 1-10, and the immersion time is 1s-300s; or When the polymer is polydimethylsiloxane, the inner wall and the outer wall of the needle tube are coated with a polydimethylsiloxane solution, the polydimethylsiloxane solution is a mixture of polydimethylsiloxane and silane coupling agent, and the mass ratio of polydimethylsiloxane to silane coupling agent is (5-15):

1.

3. Use according to claim 2, characterized in that, The step of coating the wall surface of the needle tube after anode oxidation with a layer of uniform polymer film further comprises: The needle tube immersed or coated with the polymer solution is dried, the drying temperature is 40℃-150℃, and the drying time is 1h-24h; When the needle tube impregnated with the polymer solution is dried, heat treatment is further included, which is heating at a rate of 1°C·min -1 ~ 10°C·min -1 to 365°C ~ 400°C, holding for 5 min ~ 120 min, and then furnace cooling to 250°C or below.

4. Use according to claim 1, characterized in that, The length of the needle tube is 10mm-1000mm, and the inner diameter is 0.1mm-10mm.

5. The use according to claim 1, characterized in that, The pretreatment before anode oxidation includes one or more of cleaning, nitrogen blowing and drying of the needle tube; The pretreatment also includes cleaning and drying of the conductive wire; And / or, The post-treatment after anode oxidation includes cleaning, nitrogen blowing and drying of the needle tube in deionized water.

6. Use according to claim 1, characterized in that, The conductive wire is one of metal, alloy and carbon fiber, and the diameter of the conductive wire is 0.05mm-8mm.

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