Excellent piezoelectric property and thermal stability of Pb(Sc, Nb)O3-Pb(Hf, Ti)O3 ceramic

Abstract xPb(Sc 1/2 Nb 1/2 )O 3 -(1-x)Pb(Hf 1-y Ti y )O 3 piezoelectric ceramics were prepared by solid state route, and the phase structures and piezoelectric properties of ceramics were systematically investigated. Results showed that the sample with the composition of x=0.07 and y=0.53 possessed higher phase coexistence between the rhombohedral and tetragonal, and exhibited the optimal properties among different constituent systems, i.e. T C =355 °C, d 33 =400 pC/N, ε r =1390 and tan δ =1.05%. Furthermore, the effects of temperature on d 33 , leakage current density, P - E loop, and unipolar strain were studied for xPb(Sc 1/2 Nb 1/2 )O 3 -(1-x)Pb(Hf 0.47 Ti 0.53 )O 3 samples. The sample with x=0.07 revealed better temperature stability as well, the reason of which was analyzed in detail. The study indicates that the 0.07Pb(Sc 1/2 Nb 1/2 )O 3 -0.93Pb(Hf 0.47 Ti 0.53 )O 3 piezoelectric ceramic has excellently comprehensive properties suitable for application in higher temperature condition.

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Achieving Efficient and Stable Deammonification at LowTemperatures—Experimental and Modeling Studies

Energies ◽

10.3390/en14133961 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3961

Author(s):

Hussein Al-Hazmi ◽

Xi Lu ◽

Dominika Grubba ◽

Joanna Majtacz ◽

Przemysław Kowal ◽

...

Keyword(s):

Sequencing Batch Reactor ◽

Energy Savings ◽

Batch Reactor ◽

Phase Changes ◽

Intermittent Aeration ◽

Short Term ◽

Higher Temperature ◽

Effects Of Temperature ◽

The Mathematical Model ◽

Positive Effect

The short-term effects of temperature on deammonification sludge were evaluated in a laboratory-scale sequencing batch reactor (SBR). Mathematical modeling was used for further evaluations of different intermittent aeration strategies for achieving high and stable deammonification performance at decreasing temperatures. As for the biomass cultivated at high temperatures (e.g., 30 °C), a higher temperature dependency (the adjusted Arrhenius coefficient θ for 11–17 °C = 1.71 vs. θ for 17–30 °C = 1.12) on the specific anammox growth rates was found at lower temperatures (11–17 °C) in comparison with higher temperatures (17–30 °C). Further evaluations of recovering the nitrogen removal efficiency at decreasing temperatures with the mathematical model by modifying the intermittent aeration strategies (aeration frequency (F) and the ratio (R) between non-aerated (non-aer) phase and aerated (aer) phase durations) indicated that intermittent aeration with a prolonged non-aerated phase (e.g., R ≥ 4 regardless of F value) would help to maintain high and stable deammonification performance (~80%) at decreasing temperatures (14–22 °C). Extending the non-aerated phases (increasing R) and reducing the frequency (F) of off/on phase changes have a positive effect on increasing energy savings, leading to increasing interest in this method.

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The Effect of Particle Size on the Electromechanical Properties of PZT/PVDF

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.66.238 ◽

2009 ◽

Vol 66 ◽

pp. 238-241

Author(s):

Xiao Fang Liu ◽

Hua Jun Sun ◽

Ming Wei ◽

C.X. Xiong

Keyword(s):

Particle Size ◽

Piezoelectric Ceramic ◽

Electromechanical Coupling ◽

Piezoelectric Properties ◽

Volume Fraction ◽

Relative Dielectric Constant ◽

Connectivity Pattern ◽

Conventional Solid State Reaction ◽

Pressing Method ◽

Dielectric And Piezoelectric Properties

The Nb modified PZT piezoelectric ceramic was synthesized by conventional solid-state reaction, where all of different particle sizes had the same physical properties. 0-3 modified PZT/PVDF composites were formed by hot-pressing method. The particle size effect of modified PZT on the relative dielectric and piezoelectric properties of the composites were investigated. The relative dielectric constant εr, piezoelectric constant d33 and electromechanical coupling factor kp were higher in the composite containing larger PZT particle size. The microstructures of the composites were studied by SEM, the composite with the finer PZT particle size was more homogeneous, but larger particle size was easy to be contacted. In a high volume fraction particle-loaded composite, some piezoelectric ceramic particle appeared to be in contact, as in a 1-3 connectivity pattern. The larger particle size of modified PZT itself could be seen as the grain of modified PZT contact in a 1-3 connectivity pattern and easy to be contacted each other compared to the finer particle size in the composites, thus reducing the resistance of the composites and the poling process became effective, which led to higher properties. The optimal particle size of PZT is about 100μm, the Nb modified PZT/PVDF (volume fraction 70/30) composite show higher dielectric and piezoelectric properties than the others, εr=156.6, d33=69pC/N and kp=0.358.

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The Self-Decay Characteristics of Chlorine Dioxide in Water

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.296 ◽

2012 ◽

Vol 610-613 ◽

pp. 296-299

Author(s):

Xin Jie Li ◽

Dan Nan Jiang ◽

Yue Jun Zhang

Keyword(s):

Rate Constants ◽

Tap Water ◽

Pure Water ◽

Decay Behaviour ◽

Increase With Increase ◽

Higher Temperature ◽

Effects Of Temperature ◽

Lower Temperature ◽

Kinetics Of ◽

Temperature Water

In order to learn the ClO2 decay behaviour in tap water, the kinetics of ClO2 decay in pure water was studied. Under the conditions of tap water treatment and keeping away from light, the effects of temperature and pH on ClO2 degradation were investigated. The results show that the ClO2 decay reaction in pure water is the first-order with respect to ClO2, the decay rate constants increase with increase in temperature or pH. At pH=6.87, the rate constants are 0.012h-1(15°C), 0.017h-1(25°C), 0.023h-1(35°C), and 0.029h-1(45°C), respectively. At 25°C, the rate constants are 0.0083h-1(pH=4.5), 0.0111h-1(pH=5.5), 0.0143h-1(pH=6.5), 0.0222h-1(pH=7.5), and 0.0351h-1(pH=8.5), respectively. The experimental data prove that ClO2 is more stable in acidic or lower temperature water than in neutral, alkalescent, or higher temperature water.

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The (1-x)BiFeO3-xBaTiO3-Bi(Zn0.5Ti0.5)O3 high temperature lead-free piezoelectric ceramics with strong piezoelectric properties

10.21203/rs.3.rs-329232/v1 ◽

2021 ◽

Author(s):

Yuanyuan Sun ◽

Huabin Yang ◽

Jiwen Xu ◽

Weiran Huang ◽

Minhong Jiang ◽

...

Keyword(s):

High Temperature ◽

Curie Temperature ◽

Piezoelectric Properties ◽

Ferroelectric Properties ◽

Temperature Fields ◽

Depolarization Temperature ◽

Ceramic Structure ◽

Low Dielectric ◽

Tan Δ ◽

Piezoelectric Performance

Abstract The structure, microstructure, piezoelectric properties, ferroelectric properties and Curie temperature of (1- x )BiFeO 3 - x BaTiO 3 -Bi(Zn 0.5 Ti 0.5 )O 3 +MnO 2 +Li 2 CO 3 ceramics were investigated experimentally by improved solid-state reaction approach. The crystalline structures were examined by X-ray diffractometry. When x = 0.3, the rhombohedral and pseudocubic phases coexist in the ceramic structure. It is considered that the morphotropic phase boundary was formed here. At the same time, the piezoelectric performance d 33 , Curie temperature T C , and depolarization temperature are as high as 184 pC/N, 550°C, 530°C at x = 0.3, respectively. It is worth noting that when x = 0.24, the ceramics have a high T C = 580°C and low dielectric loss tan δ = 1.9%. These results show that the BFBT-BZT system ceramics are applicable ceramics with high piezoelectric properties in high temperature fields.

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Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1552 ◽

2012 ◽

Vol 727-728 ◽

pp. 1552-1556

Author(s):

Renata Barbosa ◽

Dayanne Diniz Souza ◽

Edcleide Maria Araújo ◽

Tomás Jefférson Alves de Mélo

Keyword(s):

Thermal Stability ◽

Quaternary Ammonium ◽

Chemical Structure ◽

Quaternary Ammonium Salts ◽

Ammonium Salts ◽

Degradation Mechanisms ◽

Scanning Calorimetry ◽

Higher Temperature ◽

Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

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Effect of High Temperature on the Electrochemical and Optical Properties of Emeraldine Salt Doped with DBSA and Sulfuric Acid

Journal of Chemistry ◽

10.1155/2015/826358 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Salma Gul ◽

Anwar-ul-Haq Ali Shah ◽

Salma Bilal

Keyword(s):

Thermal Stability ◽

Cyclic Voltammetry ◽

Sulfuric Acid ◽

Effect Of Temperature ◽

Visible Spectroscopy ◽

Emeraldine Salt ◽

Higher Temperature ◽

Stability Effect ◽

Thermal Stability Of ◽

Comprehensive Study

A comprehensive study of thermally treated polyaniline in its emeraldine salt form is presented here. It offers an understanding of the thermal stability of the polymer. Emeraldine salt was prepared by a novel emulsion polymerization pathway using dodecylbenzene sulfonic acid and sulfuric acid together as dopants. The effect of temperature and heating rate on the degradation of this emeraldine salt was studied via thermogravimetric analysis. The thermally analyzed sample was collected at various temperatures, that is, 250, 490, 500, and 1000°C. The gradual changes in the structure of the emeraldine salt were followed through cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy. Results demonstrate that emeraldine salt shows high thermal stability up to 500°C. This is much higher working temperature for the use of emeraldine salt in higher temperature applications. Further heat treatment seems to induce deprotonation in emeraldine salt. Cyclic voltammetry and ultraviolet-visible spectroscopy revealed that complete deprotonation takes place at 1000°C where it loses its electrical conductivity. It is interesting to note that after the elimination of the dopants, the basic backbone of emeraldine salt was not destroyed. The results reveal that the dopants employed have a stability effect on the skeleton of emeraldine salt.

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Self-Assembly of Alkali Lignin in Tetrahydrofuran

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.57 ◽

2012 ◽

Vol 550-553 ◽

pp. 57-61

Author(s):

Hao Li ◽

Yong Hong Deng ◽

Kai Huang

Keyword(s):

Charge Transfer ◽

Electrostatic Interaction ◽

Self Assembly ◽

The Self ◽

Charge Transfer Complexes ◽

Layer By Layer ◽

Alkali Lignin ◽

Higher Temperature ◽

Effects Of Temperature

Alkali lignin (AL) was used as a polyanion to form layer-by-layer self-assembled film with PDAC as a polycation. The effects of temperature and concentration on the adsorption characteristics of AL were investigated. Iodine was added into AL solutions to study the role of π-π interaction in self-assembly of AL and PDAC. Results show that the self-assembly of AL/PDAC is mainly driven by π-π interaction and electrostatic interaction. A higher temperature or a larger concentration can enhance the aggregation of lignin. I2 can form lignin–iodine charge–transfer complexes with AL to reduce the degree of aggregation of AL, so the adsorbed amount of AL decreases significantly with increasing iodine contents.

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Ceramic particle size dependence of dielectric and piezoelectric properties of piezoelectric ceramic‐polymer composites

Journal of Applied Physics ◽

10.1063/1.345584 ◽

1990 ◽

Vol 67 (4) ◽

pp. 2024-2028 ◽

Cited By ~ 49

Author(s):

Hyeung‐Gyu Lee ◽

Ho‐Gi Kim

Keyword(s):

Particle Size ◽

Polymer Composites ◽

Piezoelectric Ceramic ◽

Size Dependence ◽

Piezoelectric Properties ◽

Ceramic Particle ◽

Dielectric And Piezoelectric Properties

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Effects of Various Types of Modified Nanoclay on The Physical, Mechanical, and Viscoelastic Characteristics of Lignocellulosic Filler-Reinforced PVC Composites

10.21203/rs.3.rs-510353/v1 ◽

2021 ◽

Author(s):

Mohammad Dahmardeh Ghalehno ◽

Behzad Kord ◽

Laleh Adlnasab

Keyword(s):

Wood Flour ◽

Dynamic Mechanical Properties ◽

Clay Nanoparticles ◽

Plastic Composites ◽

Different Types ◽

Higher Temperature ◽

Viscoelastic Characteristics ◽

Tan Δ ◽

Lignocellulosic Filler ◽

Double Hydroxide

Abstract The objective of this research was to comprehensively compare the effects of two different types of nanoclay, namely layered double hydroxide (LDH) and halloysite nanotube (HNT) on the physical, mechanical, and dynamic mechanical properties of compression-molded composite panels fabricated from wood flour (WF) and polyvinyl chloride (PVC). To achieve the desired properties in the composites, the clay nanoparticles were modified with surfactant (mLDH and mHNT) before usage. The results showed that the composite specimens with mLDH exhibited higher tensile and flexural properties (strength and moduli) than with mHNT at low content. However, at high content, the composite specimens with mHNT presented greater hydrophobicity. The DMTA results indicated that the composite specimens with mLDH demonstrated better molecular restriction and larger storage modulus than with mHNT. Besides, the loss-tangent (tan δ) peak was shifted to a higher temperature for the samples including both mLDH and mHNT than without ones. Morphological observations showed that the nanoparticles were predominantly dispersed uniformly within the polymer matrix. Overall, it is found that the addition of 3 phc mLDH clay was the most effective in the composite formulation; it has significantly enhanced the properties of the wood-plastic composites.

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