Preparation method of printable ink with high-sensitivity strain sensing

Abstract

The present invention is a preparation method of printable ink with high-sensitivity strain sensing, comprising the following steps: performing oxygen plasma treatment on carbon nanotubes; performing laser ablation treatment on the carbon nanotubes treated with oxygen plasma; pouring the carbon nanotubes treated with laser ablation and sodium dodecylbenzenesulfonate into water and stirring with a homogenizer; performing ultrasonic treatment; adding an aqueous high-elastic white glue slurry and performing homogenizer treatment; centrifuging and defoaming to obtain printable ink with high strain sensing sensitivity. In the present invention, the metal additive phase in the traditional metal particle printable ink is replaced with carbon nanotubes, thereby increasing the strain sensing sensitivity of the printable ink; the carbon nanotubes are treated with oxygen plasma to make the surface of the carbon nanotubes contain a large number of oxygen-containing functional groups; the carbon nanotubes are subjected to laser ablation treatment to produce a microstructure similar to a bush; a sodium dodecylbenzenesulfonate dispersant is introduced to increase the dispersibility of the carbon nanotubes in water.

Description

Technical Field

[0001] The present invention relates to the technical field of strain sensing, and in particular to a preparation method of printable ink with high-sensitivity strain sensing. Background Art

[0002] A resistive strain gauge is an element for measuring strain, which can convert the strain change on a mechanical component into a resistance change. Strain gauges are widely used on structures such as bridges, mechanical structures, and aircraft wings. By measuring the strain change of the structure, the magnitude and direction of the force borne by the structure can be understood, which is crucial for the design and performance evaluation of the structure.

[0003] Strain sensing sensitivity is an important parameter describing the performance of a strain sensor, which reflects the change relationship between the output signal and the input strain of the sensor when it is subjected to an external force. The higher the strain sensing sensitivity, the more obvious the change in the output signal of the corresponding strain sensor.

[0004] In the prior art, an ink containing metal particles (copper or silver) is printed on a specific substrate material to form a strain sensor with conductive properties. However, for the strain sensor prepared with the printable ink containing metal particles, due to the too high content of metal particles, the formed conduction path is relatively dense, resulting in that when the strain sensor is subjected to an external force, the change amount of its resistance value is not significant enough, thus affecting the sensitivity of the sensor. Therefore, it is necessary to develop a printable ink with high strain sensing sensitivity to achieve high sensitivity of the strain sensor. Summary of the Invention

[0005] The present invention aims to solve the deficiencies of the prior art and provides a preparation method of printable ink with high-sensitivity strain sensing.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A preparation method of printable ink with high-sensitivity strain sensing includes the following steps:

[0008] S1. Perform oxygen plasma treatment on carbon nanotubes for 3 minutes to graft oxygen-containing functional groups onto the carbon nanotubes;

[0009] S2. Perform laser ablation treatment on the oxygen plasma-treated carbon nanotubes for 3 minutes with a laser power of 1.5 W to produce a bush-like microstructure on the carbon nanotubes;

[0010] S3. Mix the laser ablation-treated carbon nanotubes and sodium dodecylbenzenesulfonate in a mass ratio of 1:1, pour them into water, and stir with a homogenizer at a temperature of 20°C and a homogenizer rotation speed of 8000 revolutions per minute for a total treatment time of 6 hours;

[0011] S4. Ultrasonically treat the solution obtained in step S3 at a temperature maintained at 10°C, with an ultrasonic power of 1200 W, an ultrasonic on-time of 1 second, an ultrasonic off-time of 2 seconds, and a total ultrasonic treatment time of 4 hours;

[0012] S5. After the ultrasonic treatment, add an aqueous high-elastic white glue slurry to the solution. The mass ratio of the aqueous high-elastic white glue slurry to the carbon nanotubes is 100:1, and perform homogenizer treatment at a temperature maintained at 20°C, with a homogenizer rotation speed of 16,000 revolutions per minute and a total treatment time of 6 hours;

[0013] S6. Centrifuge and defoam the solution obtained in step S5 to finally obtain a printable ink with high strain sensing sensitivity.

[0014] In step S1, the carbon nanotubes are prepared by mechanical exfoliation.

[0015] In step S5, the added aqueous high-elastic white glue slurry is an aqueous resin.

[0016] In step S6, the centrifugation and defoaming time is 5 minutes.

[0017] The beneficial effects of the present invention are as follows: In the present invention, the metal additive phase in the traditional printable ink of metal microparticles is replaced with carbon nanotubes, thereby increasing the strain sensing sensitivity of the printable ink; first, the carbon nanotubes obtained by mechanical exfoliation are treated with oxygen plasma, so that the surface of the carbon nanotubes contains a large number of oxygen-containing functional groups; secondly, the carbon nanotubes are subjected to laser ablation treatment to produce a microstructure similar to a bush; at the same time, a sodium dodecylbenzenesulfonate dispersant is introduced to increase the dispersibility of the carbon nanotubes in water; the high shear force of the homogenizer is used to disperse the mixed solution to obtain a printable ink with high strain sensing sensitivity. Brief Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the present invention;

[0019] Figure 2 is an SEM image of the printable ink obtained in Comparative Example 1;

[0020] Figure 3 is a strain sensing sensitivity curve graph of the printable ink obtained in Comparative Example 1;

[0021] Figure 4 is an SEM image of the printable ink obtained in Comparative Example 2;

[0022] Figure 5 is a strain sensing sensitivity curve graph of the printable ink obtained in Comparative Example 2;

[0023] Figure 6SEM image of the printable ink obtained in Specific Example 1;

[0024] Figure 7 Strain sensing sensitivity curve of the printable ink obtained in Specific Example 1;

[0025] The following will describe in detail with reference to the accompanying drawings in conjunction with the embodiments of the present invention. Specific Embodiments

[0026] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention. In the following paragraphs, the present invention will be described more specifically by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments: Specific Example 1:

[0030] A preparation method of a printable ink with high-sensitivity strain sensing, as Figure 1 shown, includes the following steps:

[0031] S1. Perform oxygen plasma treatment on carbon nanotubes for 3 minutes to graft oxygen-containing functional groups onto the carbon nanotubes; the carbon nanotubes are prepared by mechanical exfoliation;

[0032] S2. Perform laser ablation treatment on the oxygen plasma-treated carbon nanotubes for 3 minutes with a laser power of 1.5 W to produce a bush-like microstructure of the carbon nanotubes;

[0033] S3. Mix the laser ablation-treated carbon nanotubes and sodium dodecylbenzenesulfonate in a mass ratio of 1:1 and pour them into water, and stir with a homogenizer at a temperature of 20 °C and a homogenizer rotation speed of 8000 revolutions per minute for a total treatment time of 6 hours;

[0034] S4. Perform ultrasonic treatment on the solution obtained in step S3 at a temperature of 10 °C, an ultrasonic power of 1200 W, an ultrasonic on-time of 1 second, an ultrasonic off-time of 2 seconds, and a total ultrasonic treatment time of 4 hours;

[0035] S5. After the ultrasonic treatment, add an aqueous high-elastic white glue slurry into the solution. The mass ratio of the aqueous high-elastic white glue slurry to the carbon nanotubes is 100:1; the added aqueous high-elastic white glue slurry is an aqueous resin; perform homogenizer treatment, keep the temperature at 20 °C, the rotation speed of the homogenizer is 16,000 revolutions per minute, and the total treatment time is 6 hours;

[0036] S6. Centrifuge and defoam the solution obtained in step S5 for 5 minutes to finally obtain a printable ink with high strain sensing sensitivity.

[0037] Comparative Example 1:

[0038] A preparation method of a printable ink is as follows:

[0039] Perform oxygen plasma treatment on the carbon nanotubes for 3 minutes to graft more oxygen-containing functional groups onto the carbon nanotubes;

[0040] Mix the oxygen plasma-treated carbon nanotubes and sodium dodecylbenzenesulfonate at a mass ratio of 1:1, pour them into water, and stir using a homogenizer. Keep the temperature at 20 °C, the rotation speed of the homogenizer is 8,000 revolutions per minute, and the total treatment time is 6 hours;

[0041] Perform ultrasonic treatment on the solution obtained in the previous step. Keep the temperature at 10 °C, the ultrasonic power is 1,200 W, the ultrasonic on-time is 1 second, the ultrasonic off-time is 2 seconds, and the total ultrasonic treatment time is 4 hours;

[0042] After the ultrasonic treatment, add an aqueous high-elastic white glue slurry into the solution. The mass ratio of the white glue slurry to the carbon nanotubes is 100:1; perform homogenizer treatment, keep the temperature at 20 °C, the rotation speed of the homogenizer is 16,000 revolutions per minute, and the total treatment time is 6 hours;

[0043] Centrifuge and defoam the obtained solution for 5 minutes to finally obtain a printable ink.

[0044] Comparative Example 2:

[0045] A preparation method of a printable ink is as follows:

[0046] Perform laser ablation treatment on the carbon nanotubes for 3 minutes, and the laser power is 1.5 W to produce a microstructure similar to a bush on the carbon nanotubes;

[0047] Mix the laser ablation-treated carbon nanotubes and sodium dodecylbenzenesulfonate at a mass ratio of 1:1, pour them into water, and stir using a homogenizer. Keep the temperature at 20 °C, the rotation speed of the homogenizer is 8,000 revolutions per minute, and the total treatment time is 6 hours;

[0048] The solution obtained in the previous step is subjected to ultrasonic treatment at a temperature of 10°C, an ultrasonic power of 1200 W, an ultrasonic on-time of 1 second, an ultrasonic off-time of 2 seconds, and a total ultrasonic treatment time of 4 hours;

[0049] After the ultrasonic treatment, a water-based high-elastic white glue slurry is added to the solution, and the mass ratio of the white glue slurry to the carbon nanotubes is 100:1; homogenizer treatment is carried out at a temperature of 20°C, a homogenizer rotation speed of 16,000 revolutions per minute, and a total treatment time of 6 hours;

[0050] The obtained solution is centrifuged to remove bubbles for 5 minutes, and finally printable ink can be obtained.

[0051] The SEM image of the printable ink obtained in Comparative Example 1 is as Figure 2 shown, and the strain sensing sensitivity is as Figure 3 shown.

[0052] The SEM image of the printable ink obtained in Comparative Example 2 is as Figure 4 shown, and the strain sensing sensitivity is as Figure 5 shown.

[0053] The SEM image of the printable ink with high strain sensing sensitivity obtained in Specific Example 1 is as Figure 6 shown, and the strain sensing sensitivity is as Figure 7 shown.

[0054] From Figure 2 , Figure 4 , Figure 6 it can be seen that a microstructure similar to a bush will be generated on the surface of the ink obtained by laser ablation treatment, which can improve the sensitivity of the ink; from Figure 3 , Figure 5 , Figure 7 it can be seen that oxygen plasma treatment of carbon nanotubes can improve the linear sensitivity of the ink.

[0055] The present invention first performs oxygen plasma treatment on the carbon nanotube raw material for 3 minutes to graft more oxygen-containing functional groups onto the carbon nanotubes. Then, the oxygen plasma-treated carbon nanotubes are subjected to laser ablation treatment for 3 minutes with a laser power of 1.5 W to produce a microstructure similar to a bush on the carbon nanotubes. The laser ablation-treated carbon nanotubes and sodium dodecylbenzenesulfonate are mixed at a mass ratio of 1:1 and then poured into water. The high rotation speed of the homogenizer generates strong shear force to uniformly disperse the carbon nanotubes in water. After the homogenizer treatment is completed, the solution is continuously subjected to ultrasonic treatment. The role of the ultrasonic treatment is to open some small-scale agglomerated carbon nanotubes and improve the dispersibility of the carbon nanotubes. After the ultrasonic treatment ends, an aqueous high-elastic white glue slurry is added to the solution, and the solution with the elastic slurry is continuously treated by the homogenizer to uniformly and fully mix the carbon nanotubes and the white glue slurry. Finally, the obtained solution is centrifuged for defoaming for 5 minutes to prepare a printable ink with high strain sensing sensitivity.

[0056] The present invention replaces the metal additive phase in the traditional printable ink of metal particles with carbon nanotubes, thereby increasing the strain sensing sensitivity of the printable ink. First, the carbon nanotubes obtained by mechanical exfoliation are treated with oxygen plasma so that the surface of the carbon nanotubes contains a large number of oxygen-containing functional groups. Secondly, the carbon nanotubes are subjected to laser ablation treatment to produce a microstructure similar to a bush. At the same time, a sodium dodecylbenzenesulfonate dispersant is introduced to increase the dispersibility of the carbon nanotubes in water. The high shear force of the homogenizer is used to disperse the mixed solution to obtain a printable ink with high strain sensing sensitivity.

[0057] The present invention has been described exemplarily above in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above-mentioned manner. As long as various improvements are made by adopting the method concept and technical solution of the present invention, or directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a printable ink with high-sensitivity strain sensing, characterized in that: The following steps are involved: S1, treating the carbon nanotubes with oxygen plasma for 3 minutes, so that oxygen-containing functional groups are grafted onto the carbon nanotubes, and the carbon nanotubes are obtained by mechanical exfoliation; S2, performing laser ablation treatment on the carbon nanotubes treated with oxygen plasma, the treatment time is 3 minutes, the laser power is 1.5W, so that the carbon nanotubes have a bush-like microstructure; S3, mixing the laser ablated carbon nanotubes and sodium dodecylbenzene sulfonate in a mass ratio of 1:1, pouring into water, stirring with a homogenizer, maintaining the temperature at 20°C, the speed of the homogenizer at 8000 rpm, and the total treatment time for 6 hours; S4, subjecting the solution obtained in step S3 to ultrasonic treatment, maintaining the temperature at 10°C, the ultrasonic power at 1200W, the ultrasonic on time at 1 second, the ultrasonic off time at 2 seconds, and the total ultrasonic treatment time at 4 hours; S5. After the ultrasonic treatment, add water-based high-elastic white glue to the solution, the mass ratio of water-based high-elastic white glue to carbon nanotubes is 100:1, and perform homogenizer treatment. The temperature is maintained at 20° C., the speed of the homogenizer is 16,000 rpm, and the total treatment time is 6 hours. S6. Centrifugally degas the solution obtained in step S5 to finally obtain a printable ink with high strain sensing sensitivity.

2. The method for preparing a printable ink with high-sensitivity strain sensing according to claim 1, characterized in that: In step S5, the added water-based high-elastic white glue paste is a water-based resin.

3. The method for preparing a printable ink with high-sensitivity strain sensing according to claim 2, characterized in that: In step S6, the centrifugal degassing time is 5 minutes.

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