Preparation method of samarium trioxide doped lead niobate and lead zirconate titanate piezoelectric fiber sensor

Abstract

The invention discloses a preparation method of a samarium trioxide doped lead niobate and lead zirconate titanate piezoelectric fiber sensor. The preparation method comprises the following steps: firstly, preparing samarium trioxide doped lead niobate lead zirconate titanate ceramic; the preparation method comprises the following steps: grinding ceramic into powder, adding the powder and polyvinyl alcohol into a sodium alginate solution, sequentially adding lauryl sodium sulfate and citric acid, and adding excessive water into the solution to obtain low-viscosity slurry; then ball-milling to crush agglomerates and obtain a uniform suspension, finally injecting the slurry into a CaCl2 solution to obtain fibers, drying at room temperature, and calcining for the third time. By accurately controlling the molar ratio, the reaction temperature, the reaction time and the doping ratio of the raw materials, high-quality preparation of the PNN-PZT / x Sm2O3 ceramic and the fiberized piezoelectric ceramic is ensured, so that the prepared piezoelectric fiber sensor has excellent piezoelectric property and can detect external signals more sensitively.

Description

Technical Field

[0001] The present invention relates to the technical field of piezoelectric fiber sensor preparation, and in particular to a method for preparing a samarium trioxide-doped lead niobate-lead zirconate titanate piezoelectric fiber sensor. Background Art

[0002] Based on the piezoelectric effect, piezoelectric fiber sensors can convert physical quantities such as mechanical vibrations, stress fluctuations, and acoustic signals into measurable electrical signals, enabling highly sensitive, real-time dynamic monitoring. Their unique fibrous structure (diameter ≤ 0.5 mm) imparts excellent flexibility and spatial adaptability, allowing them to flexibly conform to complex surfaces or be embedded within multilayer materials, making them suitable for distributed, non-invasive sensing needs.

[0003] Produced through a high-temperature sintering process, piezoelectric fiber sensors exhibit exceptional environmental stability and maintain reliable performance across a wide temperature range of -40°C to 150°C, adapting to the demanding operating conditions of industrial equipment, aerospace, intelligent structures, healthcare, and other fields. In power systems, these sensors are particularly well-suited for monitoring the condition of cables and intermediate joints. They can accurately capture weak signals such as partial discharge (PD) and mechanical deformation, effectively overcoming the limitations of traditional infrared temperature and PD detection. Their miniaturization allows them to be wrapped directly around cable conductors or embedded in insulation, enabling long-term, stable online monitoring.

[0004] Compared to traditional sensing technologies, this sensor offers higher sensitivity and response speed in micro-vibration detection, dynamic strain monitoring, and ultrasonic sensing, enabling accurate detection of early signs of damage or abnormalities. Beyond power facilities, it also demonstrates superior performance in structural health monitoring, intelligent operations and maintenance, robotic tactile sensing, and biomechanical analysis, providing innovative solutions for modern intelligent sensing systems.

[0005] Piezoelectric ceramics are widely used in sensors, actuators, and other fields due to their excellent electromechanical coupling properties. Lead niobate zirconate titanate (PNN-PZT)-based ceramics, a typical relaxor piezoelectric material, exhibit high dielectric constant, low dielectric loss, and good temperature stability. However, traditional bulk materials suffer from poor flexibility, easy agglomeration during fiber preparation, and significant influence of grain boundaries on piezoelectric properties. Improving their performance through nanodoping and fiberization is a current research hotspot.

[0006] Samarium trioxide, as a rare earth dopant, can optimize the polarization properties and mechanical strength of ceramics by regulating lattice distortion and defects. However, further research is needed to understand the influence of Sm2O3 doping levels on the properties of PNN-PZT-based materials and optimize the parameters of the fiberization process. Furthermore, the traditional fiberization process suffers from problems such as poor slurry uniformity, low fiber forming precision, and incomplete removal of organic components, which limit the stability and sensitivity of fiber sensors. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies in the prior art and to provide a method for preparing a samarium trioxide-doped lead niobate-lead zirconate-titanate piezoelectric fiber sensor.

[0008] A method for preparing a samarium trioxide-doped lead niobate-lead zirconate-titanate piezoelectric fiber sensor, comprising: Nano-nickel oxide and nano-niobium oxide are calcined for the first time to obtain a nickel-niobium oxide precursor; lead oxide (PbO), the nickel-niobium oxide precursor, nano-zirconium dioxide, and nano-titanium dioxide are mixed, and after adding ethanol, they are ball-milled for the first time, and then Sm2O3 powder is added and ball-milled for the second time; polyvinyl alcohol is added to the mixed powder after ball milling, and the mixture is calcined for the second time to remove organic matter, thereby obtaining samarium trioxide-doped lead niobate lead zirconate titanate ceramics; The samarium trioxide-doped lead niobate lead zirconate titanate ceramic is ground into powder and added to a sodium alginate solution together with polyvinyl alcohol, followed by sodium lauryl sulfate and citric acid, and then excess water to obtain a low-viscosity slurry. The low-viscosity slurry is ball-milled to break up agglomerates to obtain a uniform suspension, and then a CaCl2 solution is injected and maintained for 60-90 minutes to obtain samarium trioxide-doped lead niobate lead zirconate titanate fibers; The samarium oxide-doped lead niobate lead zirconate titanate fiber is dried at room temperature, and then the organic components are further removed. The fiber is then calcined for the third time in a sealed alumina crucible to obtain a samarium oxide-doped lead niobate lead zirconate titanate piezoelectric fiber sensor.

[0009] In one embodiment, the first ball milling time is 12 hours, and the second ball milling time is 12 hours.

[0010] In one embodiment, the first calcination condition is: the calcination temperature is 1000 o C, calcination time is 3 hours.

[0011] In one embodiment, the second calcination conditions are: heating to 1050°C at a rate of 5°C / min, sintering for 1 hour, then heating to 1300°C at a rate of 5°C / min, sintering for 2 hours, and cooling to room temperature.

[0012] In one embodiment, the third calcination conditions are: heating at a rate of 100°C / h, placing at 200°C and 600°C for 30 minutes each, heating to 1285°C at a rate of 200°C / h and sintering for 30 minutes.

[0013] In one embodiment, the content of polyvinyl alcohol added during the preparation of the samarium trioxide-doped lead niobate lead zirconate titanate ceramic is 6 wt %.

[0014] In one embodiment, the preparation process of the samarium trioxide-doped lead niobate lead zirconate titanate ceramic further includes: pressing the mixed powder under a uniaxial pressure of 120 MPa, 500 o C for 3 hours to remove organic matter.

[0015] In one embodiment, the molar ratio of the nano-nickel oxide to the nano-niobium oxide is 1:1.

[0016] In one embodiment, the molar ratio of the lead oxide, nickel niobium oxide precursor, nano zirconium dioxide and nano titanium dioxide is 0.42:0.42:y:(0.58-y), and the value range of y is 0.2-0.3.

[0017] In one embodiment, the molar ratio of the Sm2O3 powder to nano-nickel oxide is 0.005:1-0.03:1.

[0018] The present invention ensures high-quality preparation of PNN-PZT / x Sm2O3 ceramics and fiberized piezoelectric ceramics by precisely controlling the molar ratio of each raw material, reaction temperature, time, and doping ratio. This ensures that the prepared piezoelectric fiber sensor has excellent piezoelectric properties and can more sensitively detect external signals.

[0019] The sodium alginate-CaCl2 cross-linking system combined with the ball milling dispersion process ensures uniform fiber diameter, and the temperature of the material can be flexibly controlled by adjusting the y value (Zr / Ti ratio) to meet sensing needs in different environments.

[0020] The entire preparation method is relatively simple, easy to operate and control, and suitable for large-scale industrial production. It provides technical support for the widespread application of samarium trioxide-doped lead niobate zirconate titanate (PNN-PZT / x Sm2O3) piezoelectric fiber sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by this application.

[0022] Figure 1 This is a flow chart of a method for preparing a samarium trioxide-doped lead niobate lead zirconate titanate (PNN-PZT / x Sm2O3) piezoelectric fiber sensor according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] Figure 1Flowchart of the preparation method of samarium trioxide-doped lead niobate lead zirconate titanate (PNN-PZT / x Sm2O3) piezoelectric fiber sensor according to the embodiment of the present application. Figure 1 As shown, according to some embodiments, a method for preparing a samarium trioxide-doped lead niobate zirconate titanate (PNN-PZT / x Sm2O3) piezoelectric fiber sensor includes the following steps: Step 1: Preparation of samarium trioxide-doped lead niobate zirconate titanate (PNN-PZT / x Sm2O3) ceramics Nano-nickel oxide and nano-niobium oxide are calcined for the first time to obtain a nickel-niobium oxide precursor; lead oxide PbO, nickel-niobium oxide precursor, nano-zirconium dioxide and nano-titanium dioxide are mixed, and after adding ethanol, they are ball-milled for the first time, and then Sm2O3 powder is added for the second ball-milling; wherein, the ball-milling time can be set according to actual conditions.

[0024] Polyvinyl alcohol is added to the mixed powder after ball milling, and the powder is calcined for a second time to remove organic matter, thereby obtaining PNN-PZT / x Sm2O3 ceramics, where x is the molar ratio of Sm2O3 to nickel oxide.

[0025] Step 2: Preparation of samarium trioxide-doped lead niobate zirconate titanate (PNN-PZT / x Sm2O3) piezoelectric fiber sensor Samarium trioxide-doped lead niobate lead zirconate titanate ceramic is ground into powder and added to a sodium alginate solution together with polyvinyl alcohol. Sodium lauryl sulfate and citric acid are then added in sequence, followed by an excess of water to obtain a low-viscosity slurry. The temperature of the deionized water is adjusted appropriately according to the actual production process. According to some embodiments, deionized water at 70-80°C is more soluble in sodium alginate.

[0026] The low-viscosity slurry is ball-milled to break up agglomerates to obtain a uniform suspension, and then a CaCl2 solution is injected and maintained for 60-90 minutes to obtain samarium trioxide-doped lead niobate lead zirconate titanate fibers; wherein the ball-milling time can be set according to actual conditions.

[0027] The samarium oxide-doped lead niobate lead zirconate titanate fiber is dried at room temperature, and then the organic components are further removed. The fiber is then calcined for the third time in a sealed alumina crucible to obtain a samarium oxide-doped lead niobate lead zirconate titanate piezoelectric fiber sensor.

[0028] In some embodiments, the first ball milling time is 12 hours, and the second ball milling time is 12 hours.

[0029] In some embodiments, the first calcination conditions are: calcination temperature is 1000 o C, calcination time is 3 hours.

[0030] In some embodiments, the second calcination conditions are: heating to 1050° C. at a rate of 5° C. / min, sintering for 1 hour, then heating to 1300° C. at a rate of 5° C. / min, sintering for 2 hours, and cooling to room temperature.

[0031] In some embodiments, the third calcination conditions are: heating at a rate of 100°C / h, placing at 200 and 600°C for 30 min each, heating to 1285°C at a rate of 200°C / h and sintering for 30 min.

[0032] In some embodiments, the content of polyvinyl alcohol added during the preparation of the samarium trioxide-doped lead niobate / lead zirconate titanate ceramic is 6 wt %.

[0033] In some embodiments, the preparation process of the samarium trioxide-doped lead niobate lead zirconate titanate ceramic further comprises: pressing the mixed powder into a shape under a uniaxial pressure of 120 MPa, 500 o C for 3 hours to remove organic matter.

[0034] In some embodiments, the molar ratio of the nano-nickel oxide to the nano-niobium oxide is 1:1.

[0035] In some embodiments, the molar ratio of the lead oxide, the nickel niobium oxide precursor, the nano zirconium dioxide and the nano titanium dioxide is 0.42:0.42:y:(0.58-y), and the value of y ranges from 0.2 to 0.3.

[0036] In some embodiments, the molar ratio of the Sm2O3 powder to the nano-nickel oxide is 0.005:1-0.03:1, and x=0.005-0.03.

[0037] In some embodiments, in step 2, during the preparation of the PNN-PZT / x Sm2O3 piezoelectric fiber sensor, the mass contents of polyvinyl alcohol (PVA), sodium lauryl sulfate, and 1 wt% citric acid added are 1 wt%, 0.065 wt%, and 1 wt%, respectively.

[0038] In some embodiments, the PNN-PZT / x Sm2O3 fibers were placed in glycerol for 10 minutes before drying.

[0039] In some embodiments, the drying time of the PNN-PZT / x Sm2O3 fiber is 24 hours.

[0040] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0041] Example 1: Preparation of Samarium Trioxide-Doped Lead Niobate Zirconate Titanate (PNN-PZT / x Sm2O3) Piezoelectric Fiber Sensor Step 1: Preparation of PNN-PZT / x Sm2O3 ceramics (x=0.005) Nano nickel oxide NiO and nano niobium oxide Nb2O5 powders were mixed in a molar ratio of 1:1 and heated at 1000 o C for 3 h to synthesize the precursor NiNb2O6; wherein the calcination time and calcination temperature can be set according to the actual production situation.

[0042] Lead oxide PbO, precursor NiNb2O6, nano zirconium dioxide ZrO2 and nano titanium dioxide TiO2 were milled with ethanol in a molar ratio of 0.42:0.42: :0.2:0.38 for 12 hours, and Sm2O3 powder with a molar ratio of 0.005 to NiO was added and milled for 12 hours; 100 o C drying.

[0043] 6 wt% polyvinyl alcohol was added to the dried powder and the powder was pressed into a disc under a uniaxial pressure of 120 MPa. o C for 3 hours to remove organic matter; wherein, the operation of pressing the powder into a solid can determine the use of appropriate pressure devices and pressure according to the actual situation of the powder. The shape of the powder after pressing is diverse, such as round, rectangular, square, etc.

[0044] The temperature was raised to 1050°C at a rate of 5°C / min, sintered for 1 hour, then raised to 1300°C at a rate of 5°C / min, sintered for 2 hours, and cooled to room temperature to obtain PNN-PZT / x Sm2O3 ceramics.

[0045] Step 2: Preparation of fiberized PNN-PZT / x Sm2O3 piezoelectric ceramics (x=0.005) Sodium alginate was dissolved in deionized water at 70°C to form a solution. PNN-PZT / 0.005 Sm2O3 ceramics were then ground into powder and added to the solution along with polyvinyl alcohol (PVA) at a 1wt% PVA content. 0.065wt% sodium lauryl sulfate and 1wt% citric acid were then added in proportion.

[0046] Excess water was added to obtain a low-viscosity slurry, which was then ball-milled with ZrO2 for 24 hours to break up agglomerates and obtain a homogeneous suspension. Excess water was removed by heating, and the slurry was continuously stirred. The slurry was injected into a CaCl2 solution through a 0.5 mm nozzle to obtain PNN-PZT / 0.005 Sm2O3 fibers.

[0047] The fibers were kept in a CaCl2 solution for 60 minutes, then placed in glycerol for 10 minutes, and dried at room temperature for 24 hours; In order to remove the organic components from the fiber, the temperature was raised at a rate of 100 °C / h in a closed alumina crucible, and the samples were placed at 200 °C and 600 °C for 30 min each. The temperature was then raised to 1285 °C at a rate of 200 °C / h and sintered for 30 min to prepare the PNN-PZT / x Sm2O3 piezoelectric fiber sensor with a piezoelectric coefficient d33 of 935 pC / N.

[0048] Example 2: On the basis of Example 1, the addition amounts of the precursors NiNb2O6, nano zirconium dioxide ZrO2 and nano titanium dioxide TiO2 were changed to a molar ratio of 0.42:0.42: 0.25:0.33, the molar ratio of Sm2O3 powder to NiO was changed to 0.02:1, and other conditions were the same. Finally, the PNN-PZT / x Sm2O3 piezoelectric fiber sensor with a piezoelectric coefficient d33 of 1280 pC / N was prepared.

[0049] Example 3: On the basis of Example 1, the addition amounts of the precursors NiNb2O6, nano zirconium dioxide ZrO2 and nano titanium dioxide TiO2 were changed to a molar ratio of 0.42:0.42:0.3:0.28, the molar ratio of Sm2O3 powder to NiO was changed to 0.03:1, and other conditions were the same. Finally, the PNN-PZT / x Sm2O3 piezoelectric fiber sensor with a piezoelectric coefficient d33 of 1147 pC / N was prepared.

[0050] The conventional techniques in the above embodiments are well known to those skilled in the art and will not be described in detail here. The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0051] Although the present invention has been described in detail and certain specific embodiments have been cited, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

[0052] Although the above specific embodiments have shown, described and pointed out the novel features applied to various embodiments, it should be understood that various omissions, substitutions and changes may be made to the form and details of the described devices or methods without departing from the spirit of the present disclosure. In addition, the various features and methods described above can be used independently of each other or can be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Many of the above embodiments include similar components, and therefore, these similar components are interchangeable in different embodiments. Although the present invention has been disclosed in the context of certain embodiments and examples, it should be understood by those skilled in the art that the present invention can extend beyond the specifically disclosed embodiments to other alternative embodiments and / or applications and their obvious modifications and equivalents. Therefore, the present invention is not intended to be limited by the specific disclosure of the preferred embodiments herein. Matters not covered in the present invention are all known technologies.

Claims

1. A method for preparing a samarium trioxide-doped lead niobate-lead zirconate titanate piezoelectric fiber sensor, characterized in that: The method comprises: Nano-nickel oxide and nano-niobium oxide are calcined for the first time to obtain a nickel-niobium oxide precursor; lead oxide (PbO), the nickel-niobium oxide precursor, nano-zirconium dioxide, and nano-titanium dioxide are mixed, and after adding ethanol, they are ball-milled for the first time, and then Sm2O3 powder is added and ball-milled for the second time; polyvinyl alcohol is added to the mixed powder after ball milling, and the mixture is calcined for the second time to remove organic matter, thereby obtaining samarium trioxide-doped lead niobate lead zirconate titanate ceramics; The samarium trioxide-doped lead niobate lead zirconate titanate ceramic is ground into powder and added to a sodium alginate solution together with polyvinyl alcohol, followed by sodium lauryl sulfate and citric acid, and then excess water to obtain a low-viscosity slurry. The low-viscosity slurry is ball-milled to break up agglomerates to obtain a uniform suspension, and then a CaCl2 solution is injected and maintained for 60-90 minutes to obtain samarium trioxide-doped lead niobate lead zirconate titanate fibers; The samarium oxide-doped lead niobate lead zirconate titanate fiber is dried at room temperature, and then the organic components are further removed. The fiber is then calcined for the third time in a sealed alumina crucible to obtain a samarium oxide-doped lead niobate lead zirconate titanate piezoelectric fiber sensor.

2. The preparation method according to claim 1, wherein: The first ball milling time was 12 hours, and the second ball milling time was 12 hours.

3. The preparation method according to claim 1, wherein: The first calcination conditions are: calcination temperature is 1000°C, and calcination time is 3 hours.

4. The method according to claim 1, wherein: The second calcination conditions are as follows: heating to 1050°C at a rate of 5°C / min, sintering for 1 hour, then heating to 1300°C at a rate of 5°C / min, sintering for 2 hours, and cooling to room temperature.

5. The method according to claim 1, wherein: The third calcination conditions are: heating at a rate of 100°C / h, placing at 200°C and 600°C for 30 minutes each, heating to 1285°C at a rate of 200°C / h and sintering for 30 minutes.

6. The method according to claim 1, wherein: The content of polyvinyl alcohol added during the preparation of the samarium trioxide-doped lead niobate lead zirconate titanate ceramic is 6 wt %.

7. The method according to claim 1, wherein: The preparation process of the samarium trioxide-doped lead niobate lead zirconate titanate ceramic further includes: pressing the mixed powder into a shape under a uniaxial pressure of 120 MPa, 500 o C for 3 hours to remove organic matter.

8. The method according to claim 1, wherein: The molar ratio of the nano nickel oxide to the nano niobium oxide is 1:

1.

9. The method according to claim 1, wherein: The molar ratio of the lead oxide, the nickel niobium oxide precursor, the nano zirconium dioxide and the nano titanium dioxide is 0.42:0.42:y:(0.58-y), and the value range of y is 0.2-0.

3.

10. The method according to claim 1, wherein: The molar ratio of the Sm2O3 powder to the nano-nickel oxide is 0.005:1-0.03:1.

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