Effect of carbon black on properties of 0–3 piezoelectric ceramic/cement composites

Huang Shifeng,Li Xue,Liu Futian,Chang Jun,Xu Dongyu,Cheng Xin 한국물리학회 2009 Current Applied Physics Vol.9 No.6

0–3 cement-based piezoelectric composites were fabricated using sulphoaluminate cement and piezoelectric ceramic [0.08Pb(Li1/4Nb3/4)O3 . 0.47PbTiO3 . 0.45PbZrO3] [P(LN)ZT] as raw materials by compressing technique. The influences of carbon black content on the piezoelectric and dielectric properties, electric conductivity and impedance were investigated. The results indicate that the piezoelectric strain constant d33 and piezoelectric voltage constant g33 of the composites increase gradually with a suitable carbon black addition. When the carbon black content is 0.3 wt%, both of the piezoelectric strain constant d33 and piezoelectric voltage constant g33 of the composite exist the maximum value, which are 17.45 pC N-1 and 36.3 mV m N-1, respectively. As the carbon black content increases, the dielectric constant εr, dielectric loss tanδ and electric conductivity σ of the composites all increase, while the impedance decreases. In the frequency range tested, the more the carbon black content, the higher the εr value. The planar electromechanical coupling coefficient Kp, the thickness electromechanical coupling coefficient Kt and the mechanical quality factor Qm are almost unaffected by the carbon black content.

Electromechanical properties of 2-2 cement based piezoelectric composite

Xu Dongyu,Cheng Xin,Huang Shifeng,Jiang Minhua 한국물리학회 2009 Current Applied Physics Vol.9 No.4

A 2-2 type cement based piezoelectric composites were fabricated by dice-and-fill technique. The influences of lead magnesium niobate-lead zirconate-lead titanate (PMN) ceramic volume fraction on the electromechanical properties of the composite were investigated. The results indicate that the planar electromechanical coupling factor Kp of the composite is hardly influenced by the PMN volume fraction, which fluctuates between 35% and 37%, while both the thickness electromechanical coupling factor Kt and the mechanical quality factor Qm exhibit the trend of increase. When PMN volume fraction is 69.2%, Kt could reach to 49.8%, which is larger than that of the PMN ceramic (Kt = 46%).When PMN volume fraction is 41.7%, Qm is 4.5, which is also much less than that of the PMN ceramic (Qm = 70). This means that the composite has wider frequency band and higher sensitivity to be used as transducers. With the increase of PMN volume fraction, the acoustic impedance of the composite also exhibits the trend of increase. A 2-2 type cement based piezoelectric composites were fabricated by dice-and-fill technique. The influences of lead magnesium niobate-lead zirconate-lead titanate (PMN) ceramic volume fraction on the electromechanical properties of the composite were investigated. The results indicate that the planar electromechanical coupling factor Kp of the composite is hardly influenced by the PMN volume fraction, which fluctuates between 35% and 37%, while both the thickness electromechanical coupling factor Kt and the mechanical quality factor Qm exhibit the trend of increase. When PMN volume fraction is 69.2%, Kt could reach to 49.8%, which is larger than that of the PMN ceramic (Kt = 46%).When PMN volume fraction is 41.7%, Qm is 4.5, which is also much less than that of the PMN ceramic (Qm = 70). This means that the composite has wider frequency band and higher sensitivity to be used as transducers. With the increase of PMN volume fraction, the acoustic impedance of the composite also exhibits the trend of increase.

Establishment and evaluation of the VX2 orthotopic lung cancer rabbit model: a ultra-minimal invasive percutaneous puncture inoculation method

Wang, Lijuan,Che, Keke,Liu, Zhonghong,Huang, Xianlong,Xiang, Shifeng,Zhu, Fei,Yu, Yu The Korean Society of Pharmacology 2018 The Korean Journal of Physiology & Pharmacology Vol.22 No.3

The purpose of the present work is to establish an ultra-minimal invasive percutaneous puncture inoculation method for a VX2 orthotopic lung cancer rabbit model with fewer technical difficulties, lower mortality of rabbits, a higher success rate and a shorter operation time, to evaluate the growth, metastasis and apoptosis of tumor by CT scans, necropsy, histological examination, flow cytometry and immunohistochemistry. The average inoculation time was 10-15 min per rabbit. The tumorbearing rate was 100%. More than 90% of the tumor-bearing rabbits showed local solitary tumor with 2-10 mm diameters after two weeks post-inoculation, and the rate of chest seeding was only 8.3% (2/24). The tumors diameters increased to 4-16 mm, and irregularly short thorns were observed 3 weeks after inoculation. Five weeks post-inoculation, the liquefaction necrosis and a cavity developed, and the size of tumor grew further. Before natural death, the CT images showed that the tumors spread to the chest. The flow cytometry and immunohistochemistry indicated that there was less apoptosis in VX2 orthotopic lung cancer rabbit model compared to chemotherapy drug treatment group. Minimal invasive percutaneous puncture inoculation is an easy, fast and accurate method to establish the VX2 orthotopic lung cancer rabbit model, an ideal in situ tumor model similar to human malignant tumor growth.

Investigation of temperature sensitivity of actuation performance for piezoelectric fiber composites

Lin, Xiujuan,Chen, Haiyan,Ma, Yupeng,Fisher, John G.,Huang, Shifeng,Zhang, Dou,Cheng, Xin Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.13

<P><B>Abstract</B></P> <P>Piezoelectric fiber composites (PFCs) suffer an extremely wide range of temperatures when used in various aerospace structures where temperature effects on the mechanical properties of PFCs are important. In this paper, the actuation performances of PFCs were studied when they were exposed to environmental temperatures from −15°C to 80°C. The results showed that the actuation performance of PFCs was greatly dependent on the environmental temperature. The free strain values and the calculated piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> were initially enhanced with the increase of temperature due to the restricted movement of epoxy molecule in the glassy state. The glass transition temperature range of the composite was broadened due to a large number of small pores on the surface of the Pb(Zr,Ti)O<SUB>3</SUB> (PZT) fibers, when the epoxy molecules inside the pores had different transition behaviors compared with those outside the pores. The actuation performance including free strain performance and actuation capability, as well as the piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> decreased as the temperature increased above room temperature, since the deformation of epoxy molecules in the viscoelastic state was irreversible.</P>

Enhanced dielectric properties and discharged energy density of composite films using submicron PZT particles

Chen, Guanliang,Lin, Xiujuan,Li, Jianan,Fisher, John G.,Zhang, Yan,Huang, Shifeng,Cheng, Xin Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.13

<P><B>Abstract</B></P> <P>Flexible dielectric composite films are highly desirable materials with potential application in capacitors due to their high energy density and discharged efficiency. However, agglomeration induced by the large surface energy of nanoparticles and their large dielectric losses are unfavorable to the improvement of energy density. Submicron lead zirconate titanate (PZT) particles have shown great potential as filler in achieving a high energy storage capacity because of their excellent dielectric properties and good dispersion. In this work, calcined PZT particles were used to prepare PZT/polyvinylidene fluoride (PVDF) composite films. The results showed that composite films of high quality could be obtained even with high contents of submicron PZT particles. The introduction of PZT particles significantly improved the dielectric performance of composite films compared with that of the pristine PVDF film. The discharged energy density of composite films with 10 vol% PZT particles achieved 6.41 J/cm<SUP>3</SUP> at 250 kV/mm. A high efficiency of 87.25% was obtained at 50 kV/mm. These findings confirm the feasibility of PZT particles as inorganic filler in composite films for energy storage applications.</P>