Preparation method of tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor

Abstract

This invention discloses a method for preparing a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor. This method significantly improves the sensitivity and stability of the piezoelectric fiber by optimizing the ceramic synthesis process and fiberization steps, and further enhances the piezoelectric performance through SnO2 nanoparticle doping. A sodium alginate and polyvinyl alcohol composite system combined with wet spinning technology is used to achieve efficient ceramic fiber forming, and organic components are removed through a gradient sintering process, ultimately yielding a high-performance piezoelectric fiber sensor. This method solves the problems of poor mechanical properties and low doping uniformity of traditional piezoelectric materials, making it suitable for high-precision sensor applications.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric fiber sensor fabrication technology, and in particular to a method for fabricating a tin dioxide-doped lead niobate-lead zirconate titanate (PNN-PZT / xSnO2) piezoelectric fiber sensor. Background Technology

[0002] Piezoelectric fiber sensors, with their excellent electromechanical coupling characteristics and flexible structure, have shown broad application prospects in the field of intelligent sensing. Based on the piezoelectric effect, the sensor responds to external mechanical vibration, stress, or acoustic excitation through internal polarized charges, converting various physical quantities into measurable electrical signals. Their unique fiber morphology supports multiple integration methods, including surface bonding via high-temperature adhesives and embedding within composite materials, providing flexible sensing solutions for different application scenarios.

[0003] Compared to traditional piezoelectric ceramics (such as PZT), this sensor overcomes inherent defects such as high mechanical brittleness and poor doping uniformity, significantly improving sensitivity and environmental adaptability, and providing an innovative solution for high-precision, multi-functional sensing needs. For example, in the field of medical and health monitoring, piezoelectric fiber sensors can be integrated into wearable devices to monitor physiological signals such as human pulse and respiration in real time; in intelligent structural health monitoring, its flexible characteristics allow it to conform to complex curved surfaces and accurately sense structural vibration and deformation; in industrial automation control, this sensor can achieve real-time dynamic monitoring of equipment operating status; in the field of power monitoring, this sensor converts physical quantities such as mechanical vibration and stress fluctuations into detectable electrical signals through the piezoelectric effect, providing a new technical means for power system operating status assessment.

[0004] Piezoelectric fiber sensors can be flexibly deployed on conductor surfaces or embedded between insulating layers to sense stress waves and vibration signals caused by partial discharge, mechanical deformation, or temperature changes in real time. Compared to traditional detection methods, their high sensitivity, wide frequency response, and excellent electromagnetic interference resistance make them outstanding in detecting weak signals. Simultaneously, the flexibility of the fiber structure allows it to adapt to complex curved surfaces, ensuring a close fit with the monitored object and improving the accuracy of signal acquisition. Furthermore, this sensor can be combined with intelligent diagnostic algorithms to achieve early fault warnings for equipment through the analysis of vibration modes and acoustic emission characteristics, providing reliable assurance for the safe operation of power systems.

[0005] Lead niobate and lead zirconate titanate (PNN-PZT) are high-performance piezoelectric ceramic materials with excellent piezoelectric properties. However, there is still room for improvement in certain aspects of PNN-PZT alone. Tin dioxide (SnO2) possesses unique electrical and optical properties. Doping it into PNN-PZT can improve its piezoelectric properties, enhance the sensitivity and stability of sensors, and so on.

[0006] However, existing preparation methods have many shortcomings in terms of synthesis process, doping uniformity, and fiber forming quality, resulting in unstable performance and poor repeatability of the prepared piezoelectric fiber sensors, which limits their large-scale application and further development. Therefore, developing a new and efficient method for preparing tin dioxide-doped lead niobate-lead zirconate titanate (PNN-PZT / xSnO2) piezoelectric fiber sensors is of significant practical importance. Furthermore, the fiberization process often employs high-temperature melting, which makes it difficult to control fiber diameter and structural uniformity. This invention solves the above problems by optimizing the ceramic synthesis and wet spinning processes. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for preparing a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor.

[0008] The method for preparing the tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor of the present invention includes:

[0009] A method for fabricating a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor, characterized in that the method comprises:

[0010] Nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders were mixed and calcined to obtain the precursor NiNb2O6.

[0011] Lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) were mixed and ball-milled, and then calcined to obtain single-phase PNN-PZT powder.

[0012] Single-phase PNN-PZT powder was calcined to obtain ceramic blocks; the ceramic blocks were ground into powder, then SnO2 powder was added and mixed, and then pressed and calcined to obtain PNN-PZT / xSnO2 ceramics.

[0013] PNN-PZT / xSnO2 ceramic was ground into powder and added together with polyvinyl alcohol (PVA) to a sodium alginate solution. Sodium dodecyl sulfate and citric acid were added in sequence, and the mixture was ball-milled to obtain a uniform suspension. The resulting suspension was then injected into a CaCl2 solution to obtain PNN-PZT / xSnO2 fibers.

[0014] The PNN-PZT / xSnO2 fiber was kept in CaCl2 solution for a period of time, then placed in glycerol for a period of time and then dried at room temperature.

[0015] In a closed alumina crucible, the dried PNN-PZT / xSnO2 fibers were placed at medium and high temperatures for a period of time, and finally heated to over 1000℃ and sintered for a period of time to obtain a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor.

[0016] Preferably, the molar ratio of the nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders is 1:1.

[0017] Preferably, the molar ratio of lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) is 0.55:0.55:(0.1-0.2):(0.25-0.35).

[0018] Preferably, the molar ratio of the single-phase PNN-PZT to SnO2 is 1:(0.01-0.02).

[0019] Preferably, the calcination conditions during the preparation of the calcined synthesis precursor NiNb2O6 are 1000 °C. o Calcination at C for 3 hours.

[0020] Preferably, the calcination conditions during the preparation of the single-phase PNN-PZT are 1050 °C. o Calcination at C for 4 hours.

[0021] Preferably, the calcination conditions for the ceramic bulk during the preparation of the PNN-PZT / xSnO2 ceramic are 1200 °C. o Calcination at C for 2 hours, followed by pressing and calcination with SnO2 powder added, with the conditions being 1310 °C. o Calcination at C for 1 hour.

[0022] Preferably, the sodium dodecyl sulfate in the suspension has a mass content of 0.065 wt%, and the citric acid in the suspension has a mass content of 1 wt%.

[0023] Preferably, during the drying process of the PNN-PZT / xSnO2 fiber, the PNN-PZT / xSnO2 fiber is kept in CaCl2 solution for 60-90 minutes, placed in glycerol for 10 minutes, and dried at room temperature for 24 hours.

[0024] Preferably, in the preparation process of the tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor, the dried PNN-PZT / xSnO2 is heated in a closed alumina crucible at a rate of 100 °C / h, and placed at 200 °C and 600 °C for 30 min each, then heated to 1285 °C at a rate of 200 °C / h and sintered for 30 min.

[0025] The beneficial effects of this invention are at least as follows:

[0026] This invention ensures high-quality preparation of PNN-PZT / xSnO2 ceramics and fibrous piezoelectric ceramics by precisely controlling the molar ratio of each raw material, reaction temperature, time, and doping ratio. This results in piezoelectric fiber sensors with excellent piezoelectric properties, enabling more sensitive detection of external signals. Through a high-temperature sintering process, the sensors exhibit stable performance over a wide temperature range of -40℃ to 150℃, making them suitable for complex environments such as cable tunnels and high-voltage switchgear.

[0027] During the fiber formation process, the rational selection of additives and optimization of molding technology effectively improve the forming quality of the fibers, significantly enhancing their density, uniformity, and strength, thereby improving the stability and repeatability of the sensors. The fibrous structure (diameter ≤ 0.5 mm) can be adhered to the cable surface or embedded in the joint insulation layer, enabling distributed, non-invasive monitoring.

[0028] The entire preparation method is relatively simple, easy to operate and control, and suitable for large-scale industrial production, providing technical support for the widespread application of tin dioxide-doped lead niobate-lead zirconate titanate (PNN-PZT / xSnO2) piezoelectric fiber sensors. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without exceeding the scope of protection claimed by the present invention.

[0030] Figure 1 This is a flowchart of a method for fabricating a tin dioxide-doped lead niobate-lead zirconate titanate (PNN-PZT / xSnO2) piezoelectric fiber sensor according to an embodiment of the present invention. Detailed Implementation

[0031] The embodiments and examples of the present invention will be described in detail below. However, those skilled in the art will understand that the following embodiments and examples are for illustrative purposes only and should not be considered as limiting the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise specified, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0032] It should be noted that:

[0033] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0034] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0035] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0036] Unless otherwise specified, the components or preferred components involved in this invention can be combined with each other to form new technical solutions.

[0037] In this invention, unless otherwise stated, the "scope" disclosed herein may take the form of a lower limit and an upper limit, and may be one or more lower limits and one or more upper limits, respectively.

[0038] In this invention, unless otherwise stated, the various reactions or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0039] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0040] At least one embodiment provides a method for fabricating a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor, the method comprising:

[0041] Step 1: Preparation of PNN-PZT / xSnO2 ceramics, where x is 0.01-0.02.

[0042] (1) Nano nickel oxide NiO and nano niobium oxide Nb2O5 powders were mixed and calcined to obtain the precursor NiNb2O6.

[0043] One embodiment provides that the molar ratio of the nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders is 1:1.

[0044] One embodiment provides that the calcination conditions during the preparation of the calcined synthesis precursor NiNb2O6 are 1000 °C. o Calcination at C for 3 hours.

[0045] (2) Lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2) and nano-titanium dioxide (TiO2) are mixed and ball-milled, and then calcined to obtain single-phase PNN-PZT powder.

[0046] One embodiment provides that the molar ratio of lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) is 0.55:0.55:(0.1-0.2):(0.25-0.35).

[0047] One embodiment provides that the calcination conditions during the preparation of the single-phase PNN-PZT are 1050 °C. o Calcination at C for 4 hours.

[0048] One embodiment provides that the ball milling solvent is ethanol, and the ball milling time is 24 hours.

[0049] (3) The single-phase PNN-PZT powder is calcined to obtain a ceramic block; the ceramic block is ground into powder, and SnO2 powder is added and mixed, and then pressed and calcined to obtain PNN-PZT / xSnO2 ceramic.

[0050] One embodiment provides that the molar ratio of the single-phase PNN-PZT to SnO2 is 1:(0.01-0.02).

[0051] One embodiment provides that the ceramic bulk calcination conditions during the preparation of the PNN-PZT / xSnO2 ceramic are 1200 °C. o Calcination at C for 2 hours, followed by pressing and calcination of the mixture after adding SnO2 powder, with the mixture pressed into a solid at 1310°C. o Calcination at C for 1 hour.

[0052] One embodiment provides that the SnO2 powder has a particle size of 50-70 nm.

[0053] Step 2: Preparation of fibrous PNN-PZT / xSnO2 piezoelectric ceramics

[0054] (1) After grinding PNN-PZT / xSnO2 ceramic into powder, it is added to sodium alginate solution along with polyvinyl alcohol (PVA), sodium dodecyl sulfate and citric acid are added in sequence, including the addition of excess water to obtain a low viscosity slurry. After ball milling, a uniform suspension is obtained. The obtained suspension can be injected into CaCl2 solution through a 0.5 mm nozzle to obtain PNN-PZT / xSnO2 fibers.

[0055] One embodiment provides that sodium alginate is dissolved in deionized water at 70-80°C to form a sodium alginate solution.

[0056] One embodiment provides that the sodium dodecyl sulfate in the suspension has a mass content of 0.065 wt%, and the citric acid in the suspension has a mass content of 1 wt%.

[0057] One embodiment provides that the content of polyvinyl alcohol (PVA) is 1 wt%.

[0058] One embodiment provides ball milling conditions for a low-viscosity slurry, which is ball milled with ZrO2 for 24 hours to break up agglomerates.

[0059] One embodiment provides that after ball milling, excess water is removed by heating and the slurry is continuously stirred.

[0060] (2) The PNN-PZT / xSnO2 fiber was kept in CaCl2 solution for a period of time, and then placed in glycerol for a period of time before being dried at room temperature.

[0061] One embodiment provides that, during the drying process of the PNN-PZT / xSnO2 fiber, the PNN-PZT / xSnO2 fiber is kept in CaCl2 solution for 60-90 minutes, placed in glycerol for 10 minutes, and dried at room temperature for 24 hours.

[0062] (3) In a closed alumina crucible, the dried PNN-PZT / xSnO2 fiber was placed at medium and high temperature for a period of time, and finally heated to over 1000℃ and sintered for a period of time to obtain a tin dioxide-doped lead niobate lead zirconate titanate piezoelectric fiber sensor.

[0063] One embodiment provides that, in the preparation process of the tin dioxide-doped lead niobate / lead zirconate titanate piezoelectric fiber sensor, the dried PNN-PZT / xSnO2 is heated in a closed alumina crucible at a rate of 100 °C / h, and placed at 200 °C and 600 °C for 30 min each, then heated to 1285 °C at a rate of 200 °C / h and sintered for 30 min.

[0064] The technical solution of the present invention will be further explained and described below with reference to several preferred embodiments, but the experimental conditions and setting parameters therein should not be regarded as limitations on the basic technical solution of the present invention. Furthermore, the scope of protection of the present invention is not limited to the following embodiments.

[0065] Example 1:

[0066] Step 1: Preparation of PNN-PZT / xSnO2 ceramics, where x is 0.01.

[0067] (1) Nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders were mixed at a molar ratio of 1:1 and then heated at 1000 rpm. o Calcination at C for 3 hours yielded the precursor NiNb2O6.

[0068] (2) Lead oxide (PbO), precursor NiNb₂O₆, nano-zirconium dioxide (ZrO₂), and nano-titanium dioxide (TiO₂) were mixed in a molar ratio of 0.55:0.55:0.1:0.35 and then ball-milled for 24 hours using ethanol as the ball-milling solvent. Then, the mixture was 1050 mL of water. o Single-phase PNN-PZT powder was obtained by calcination at C for 4 hours.

[0069] (3) The single-phase PNN-PZT powder was heated at 1200 °C o Calcination at C for 2 hours yielded a ceramic block; the ceramic block was ground into powder, and then SnO2 powder was added and mixed. The molar ratio of single-phase PNN-PZT to SnO2 was 1:0.01. The mixture was pressed into a solid and then 1310 o PNN-PZT / xSnO2 ceramics were obtained by calcination at C for 1 hour. The particle size of the SnO2 powder was 50 nm.

[0070] Step 2: Preparation of fibrous PNN-PZT / xSnO2 piezoelectric ceramics

[0071] (1) Dissolve sodium alginate in deionized water at 70°C to form a sodium alginate solution. Grind PNN-PZT / xSnO2 ceramic into powder and add it to the sodium alginate solution along with 1 wt% polyvinyl alcohol (PVA). Then add 0.065 wt% sodium dodecyl sulfate, 1 wt% citric acid, and excess water to obtain a low-viscosity slurry. Ball mill the low-viscosity slurry with ZrO2 for 24 hours to break up the agglomerates and obtain a uniform suspension. After ball milling, remove excess water by heating and continuously stir the slurry. Inject the resulting suspension into a CaCl2 solution through a 0.5 mm nozzle to obtain PNN-PZT / xSnO2 fibers.

[0072] (2) Keep the PNN-PZT / xSnO2 fiber in CaCl2 solution for 60 minutes, place it in glycerol for 10 minutes, and dry it at room temperature for 24 hours.

[0073] (3) In a closed alumina crucible, the dried PNN-PZT / xSnO2 fiber was heated at a rate of 100 ℃ / h and placed at 200 and 600 ℃ for 30 min each. The temperature was then increased to 1285 ℃ at a rate of 200 ℃ / h and sintered for 30 min to obtain a PNN-PZT / 0.01SnO2 piezoelectric fiber sensor with a piezoelectric constant d33 of 1060 PC / N and a sensitivity of approximately -20.6 dB.

[0074] Example 2:

[0075] Based on Example 1, the molar ratio of lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) was changed to 0.55:0.55:0.2:0.25, and the molar ratio of single-phase PNN-PZT to SnO2 was changed to 1:0.015, with other conditions remaining the same. Finally, a PNN-PZT / 0.015 SnO2 piezoelectric fiber sensor was prepared with a piezoelectric constant d33 of 1340 PC / N.

[0076] Example 3:

[0077] Based on Example 1, the molar ratio of lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) was changed to 0.55:0.55:0.15:0.3, and the molar ratio of single-phase PNN-PZT to SnO2 was changed to 1:0.02, with other conditions remaining the same. Finally, a PNN-PZT / 0.02 SnO2 piezoelectric fiber sensor was prepared with a piezoelectric constant d33 of 1240 PC / N.

[0078] The conventional techniques described in the above embodiments are existing technologies known to those skilled in the art, and therefore will not be elaborated upon here. The specific embodiments described herein are merely illustrative examples of the spirit of the invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described specific embodiments or use similar methods to replace them, but without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0079] Although the present invention has been described in detail and specific embodiments have been cited, it will be apparent to those skilled in the art that various changes or modifications can be made without departing from the spirit and scope of the invention.

[0080] While the foregoing detailed descriptions have shown, described, and pointed out novel features applicable to various embodiments, it should be understood that various omissions, substitutions, and changes may be made to the form and details of the described apparatus or methods without departing from the spirit of this disclosure. Furthermore, the various features and methods described above may be used independently of each other or may be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of this disclosure. Many of the foregoing embodiments include similar components, and therefore, these similar components are interchangeable in different embodiments. Although the invention has been disclosed in the context of certain embodiments and examples, those skilled in the art will understand that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or applications, as well as their obvious modifications and equivalents. Therefore, the invention is not intended to be limited to the specific disclosure of the preferred embodiments herein. All matters not covered herein are well-known.

Claims

1. A method for fabricating a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor, characterized in that, The method includes: Nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders were mixed and calcined to obtain the precursor NiNb2O6. Lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) were mixed and ball-milled, and then calcined to obtain single-phase PNN-PZT powder. Single-phase PNN-PZT powder was calcined to obtain ceramic blocks; the ceramic blocks were ground into powder, then SnO2 powder was added and mixed, and then pressed and calcined to obtain PNN-PZT / xSnO2 ceramics. PNN-PZT / xSnO2 ceramic was ground into powder and added together with polyvinyl alcohol (PVA) to a sodium alginate solution. Sodium dodecyl sulfate and citric acid were added in sequence, and the mixture was ball-milled to obtain a uniform suspension. The resulting suspension was then injected into a CaCl2 solution to obtain PNN-PZT / xSnO2 fibers. The PNN-PZT / xSnO2 fiber was kept in CaCl2 solution for a period of time, then placed in glycerol for a period of time and then dried at room temperature. In a closed alumina crucible, the dried PNN-PZT / xSnO2 fibers were placed at medium and high temperatures for a period of time, and finally heated to over 1000℃ and sintered for a period of time to obtain a tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor.

2. The preparation method according to claim 1, characterized in that, The molar ratio of the nano-nickel oxide (NiO) and nano-niobium oxide (Nb2O5) powders is 1:

1.

3. The preparation method according to claim 1, characterized in that, The molar ratio of lead oxide (PbO), precursor NiNb2O6, nano-zirconium dioxide (ZrO2), and nano-titanium dioxide (TiO2) is 0.55:0.55:(0.1-0.2):(0.25-0.35).

4. The preparation method according to claim 1, characterized in that, The molar ratio of the single-phase PNN-PZT to SnO2 is 1:(0.01-0.02).

5. The preparation method according to claim 1, characterized in that, The calcination conditions for preparing the calcined precursor NiNb2O6 are 1000 °C. o Calcination at C for 3 hours.

6. The preparation method according to claim 1, characterized in that, The calcination conditions during the preparation of the single-phase PNN-PZT are 1050 °C. o Calcination at C for 4 hours.

7. The preparation method according to claim 1, characterized in that, The ceramic bulk calcination conditions during the preparation of the PNN-PZT / xSnO2 ceramic are 1200 °C. o Calcination at C for 2 hours, followed by pressing and calcination with SnO2 powder added, under conditions of 1310 °C. o Calcination at C for 1 hour.

8. The preparation method according to claim 1, characterized in that, The sodium dodecyl sulfate in the suspension has a mass content of 0.065 wt%, and the citric acid in the suspension has a mass content of 1 wt%.

9. The preparation method according to claim 1, characterized in that, During the drying process of the PNN-PZT / xSnO2 fiber, the PNN-PZT / xSnO2 fiber is kept in CaCl2 solution for 60-90 minutes, placed in glycerol for 10 minutes, and dried at room temperature for 24 hours.

10. The preparation method according to claim 1, characterized in that, In the fabrication process of the tin dioxide-doped lead niobate and lead zirconate titanate piezoelectric fiber sensor, the dried PNN-PZT / xSnO2 is heated in a closed alumina crucible at a rate of 100℃ / h, and placed at 200℃ and 600℃ for 30 min each. Then, the temperature is increased to 1285℃ at a rate of 200℃ / h and sintered for 30 min.

Images