Electrorheological Properties of Suspensions Based on Polyaniline-montmorillonite Clay Nanocomposite

2002 ◽  
Vol 17 (6) ◽  
pp. 1513-1519 ◽  
Author(s):  
Jun Lu ◽  
Xiaopeng Zhao
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Yield Stress ◽  
Electric Fields ◽  
High Dielectric Constant ◽  
Silicone Oil ◽  
Transmission Electron ◽  
High Dielectric ◽  
Er Fluid ◽  
Electrorheological Properties

It is thought that high-dielectric constant, suitable conductivity, and dielectric loss dominate electrorheological (ER) effects. According to this viewpoint, the polyaniline/montmorillonite nanocomposite (PANI-MMT) particles with high-dielectric constant and suitable conductivity were synthesized by an emulsion intercalation method. The electrorheological properties of the suspensions of PANI-MMT particles in silicone oil have been investigated under direct current electric fields. At room temperature, it was found that the yield stress of PANI-MMT ER fluid was 7.19 kPa in 3 kV/mm, which is much higher than that of pure polyaniline (PANI), that of pure montmorillonite (MMT) as well as that of the mixture of polyaniline with clay (PANI+MMT). In the range of 10–100 °C, the yield stress changed only 6.5% with the variation of temperature. The sedimentation ratio of PANI-MMT ERF was about 98% after 60 days. The structure of PANI-MMT particles was characterized by infrared, x-ray diffraction (XRD), and transmission electron microscopy (TEM) spectrometry, respectively. The XRD spectra show that the inner layer distance of PANI-MMT can be enhanced to 1.52 nm when the PANI was inserted into the interlayer of MMT, whereas it is only 0.96 nm for free MMT. TEM shows that the diameter of PANI-MMT particles is about 100 nm. The dielectric constant of PANI-MMT nanocomposite was increased 5.5 times that of PANI and 2.7 times that of MMT, besides, the conductivity of PANI-MMT particle was increased about 8.5 times that of PANI at 1000 Hz. Meanwhile, the dielectric loss tangent can also be increased about 1.7 times that of PANI. It is apparent that the notable ER effect of PANI-MMT ER fluid was attributed to the prominent dielectric property of the polyaniline-montmorillonite nanocomposite particles.

High-Dielectric-Constant PLZT Films on Metal Foils for Embedded Passives

2010 ◽  
Vol 2010 (1) ◽  
pp. 000521-000527
Author(s):  
Beihai Ma ◽  
Manoj Narayanan ◽  
U. (Balu) Balachandran
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Electric Fields ◽  
High Dielectric Constant ◽  
Breakdown Strength ◽  
Time To Failure ◽  
Lead Lanthanum Zirconate Titanate ◽  
Metal Foils ◽  
Accelerated Lifetime ◽  
High Dielectric

Ceramic film capacitors with high dielectric constant and high breakdown strength would result in advanced power electronic devices with higher performance, improved reliability, and enhanced volumetric and gravimetric efficiencies. We have grown ferroelectric films of lead lanthanum zirconate titanate (PLZT) on base metal foils by chemical solution deposition. Their dielectric properties were characterized over the temperature range between −50 and 150°C. We measured a dielectric constant of ≈700 and dielectric loss of ≈0.07 at −50°C and a dielectric constant of ≈2200 and dielectric loss of ≈0.06 at 150°C. At room temperature, we measured a leakage current density of ≈6.6 × 10−9 A/cm2, mean breakdown strength of 2.6 MV/cm, and energy density >85 J/cm3. A series of highly accelerated lifetime tests (HALT) was performed to determine the reliability of these PLZT film-on-foil capacitors under high temperature and high field stress conditions. Samples were exposed to temperatures ranging from 100 to 150°C and electric fields ranging from 8.7 × 105 V/cm to 1.3 × 106 V/cm during the HALT testing. Breakdown behavior of the samples was evaluated by Weibull analysis. The mean time to failure was projected to be >3000 h at 100°C with a dc electric field of ≈2.6 × 105 V/cm.

Skin–core structured fluorinated MWCNTs: a nanofiller towards a broadband dielectric material with a high dielectric constant and low dielectric loss

2018 ◽  
Vol 6 (9) ◽  
pp. 2370-2378 ◽  
Author(s):  
Yang Liu ◽  
Cheng Zhang ◽  
Benyuan Huang ◽  
Xu Wang ◽  
Yulong Li ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Dielectric Material ◽  
Epoxy Composite ◽  
Low Dielectric ◽  
High Dielectric

A novel skin–core structured fluorinated MWCNT nanofiller was prepared to fabricate epoxy composite with broadband high dielectric constant and low dielectric loss.

scholarly journals Crown ether-containing polyimides with high dielectric constant

RSC Advances ◽  
2017 ◽  
Vol 7 (38) ◽  
pp. 23309-23312 ◽  
Author(s):  
Ting Yang ◽  
Wenhui Xu ◽  
Xinwen Peng ◽  
Haoqing Hou
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Crown Ether ◽  
High Dielectric Constant ◽  
Low Dielectric ◽  
High Dielectric

Crown ether-containing polyimides possess high dielectric constant and low dielectric loss, without sacrificing other properties.

Fluoro-polymer functionalized graphene for flexible ferroelectric polymer-based high-k nanocomposites with suppressed dielectric loss and low percolation threshold

Nanoscale ◽  
2014 ◽  
Vol 6 (24) ◽  
pp. 14740-14753 ◽  
Author(s):  
Ke Yang ◽  
Xingyi Huang ◽  
Lijun Fang ◽  
Jinliang He ◽  
Pingkai Jiang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Percolation Threshold ◽  
High Dielectric Constant ◽  
Functionalized Graphene ◽  
Ferroelectric Polymer ◽  
Flexible Polymer ◽  
High K ◽  
High Dielectric

Fluoro-polymer functionalized graphene was synthesized for flexible polymer-based nanodielectrics. The resulting nanocomposites exhibit high dielectric constant, suppressed dielectric loss and low percolation threshold.

Preparation and properties of thermostable well-functionalized graphene oxide/polyimide composite films with high dielectric constant, low dielectric loss and high strength via in situ polymerization

2015 ◽  
Vol 3 (18) ◽  
pp. 10005-10012 ◽  
Author(s):  
Xinliang Fang ◽  
Xiaoyun Liu ◽  
Zhong-Kai Cui ◽  
Jun Qian ◽  
Jijia Pan ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Low Dielectric ◽  
High Dielectric

Thermostable well-functionalized graphene oxide/polyimide composites with high dielectric constant and low dielectric loss were obtained at a low percolation threshold.

Polyimide composites composed of covalently bonded BaTiO3@GO hybrids with high dielectric constant and low dielectric loss

RSC Advances ◽  
2016 ◽  
Vol 6 (90) ◽  
pp. 86817-86823 ◽  
Author(s):  
Leipeng Liu ◽  
Yihe Zhang ◽  
Fengzhu Lv ◽  
Wangshu Tong ◽  
Ling Ding ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
Low Dielectric ◽  
Three Phase ◽  
Covalently Bonded ◽  
Polyimide Composites ◽  
High Dielectric

Novel flexible three-phase high-k polyimide composites were fabricated by the incorporation of covalently bonded BaTiO3@GO hybrids in which the BaTiO3@GO hybrids were prepared by the reaction of amino modified BaTiO3 particles and GO.

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