scholarly journals Polyaniline: tin oxide polymeric nanocomposite films. An electrical and dielectric study

2018 ◽  
Vol 36 (4) ◽  
pp. 711-716 ◽  
Author(s):  
Rajeev Arora ◽  
Subhash Chand ◽  
Pankaj Sharma
Keyword(s):  
Dielectric Constant ◽  
Polyvinyl Alcohol ◽  
Nanocomposite Film ◽  
Ac Conductivity ◽  
In Situ Polymerization ◽  
Polymer Nanocomposite ◽  
Dielectric Behavior ◽  
Nanocomposite Films ◽  
Dielectric Study ◽  
High Dielectric

AbstractA conducting nanocomposite film of 60 nm nano-SnO2-polyaniline (PANI) and polyvinyl alcohol (PVA) has been synthesized and analyzed in terms of AC conductivity and dielectric behavior. The conducting polymer nanocomposite of PANI/60 nm (SnO2) and polyvinyl alcohol (PVA) has been prepared via in situ polymerization technique. The morphology of the nanocomposite film has been studied by SEM. The film has been characterized in terms of DC conductivity. The dielectric behavior and AC conductivity of the nanocomposite film have been investigated in the frequency range of 2 Hz to 90 KHz. The film has high dielectric constant which may be correlated with polarization. It has been observed that both dielectric loss and dielectric constant decrease with an increase in frequency.

Surface Micro Topographical and Dielectric Studies of Cholesterol Crystals

2013 ◽  
Vol 665 ◽  
pp. 289-296
Author(s):  
Poorvesh M. Vyas ◽  
Mihir J. Joshi
Keyword(s):  
Dielectric Constant ◽  
Acetic Acid Solution ◽  
Dielectric Behavior ◽  
Major Constituent ◽  
Dielectric Study ◽  
Cholesterol Crystals ◽  
Ir Studies ◽  
High Dielectric ◽  
Main Component ◽  
High Level

Cholesterol is a main component in mammalian cell membranes and lipoproteins. High level of cholesterol in blood can damage arteries and potentially linked with cardiovascular diseases. Cholesterol is also major constituent of gall stones. Cholesterol crystals were grown by single diffusion gel growth technique using neutral silica gel set by acetic acid. Solution of cholesterol prepared in acetone was poured as a supernatant solution on set gel. Transparent, thin, platelet type crystals were grown. Powder XRD and FT IR studies were carried out for the confirmation of crystal system and chemical bonding. The surface micro topographical study was carried out by using SEM and AFM and interesting features were observed. As cholesterol possesses high dielectric constant, it functions as an insulting cover for the transmission of electric impulses in the nervous tissues; therefore, the dielectric study was carried to understand its dielectric behavior in the frequency range from 50 Hz to 5 MHz. The dielectric constant decreased as the frequency of applied field increased. The a.c. conductivity and a.c. resistivity were also calculated.

Preparation and Dielectric Property of Al2O3 Surface Coating Modified BaTiO3/Polyimide Composite Film

2014 ◽  
Vol 908 ◽  
pp. 63-66
Author(s):  
Ya Jun Wang ◽  
Xiao Juan Wu ◽  
Chang Gen Feng
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Chemical Properties ◽  
Dielectric Strength ◽  
Xrd Analysis ◽  
Nanocomposite Films ◽  
The Matrix

Polyimide (PI) was chosen as the matrix of the composite, barium titanate/polyimide (BT/PI) nanocomposite films were prepared by in situ polymerization. In order to improve the dispersion and the physical-chemical properties of BT surface, barium titanate was modified by Al2O3coating and modified BT/PI nanocomposite films were prepared. The prepared modified BT was characterized by X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), and the dielectric properties of the composites were characterized in detail. It was shown that surface modification with Al2O3is the chemical process and there were new substances forming. When BT was modified by 10 wt% Al2O3, the dielectric constant of the composite film was 18.96 (103Hz), the loss tangent 0.005, breakdown strength 70 MV·m-1, energy storage density 0.41 J·cm-3. The dielectric constant of BT modified by Al2O3is decreased while the dielectric strength of the modified BT/PI composite film is increased.

Dielectric Behavior of Barium Titanate/Carbon Fibers Composites

2017 ◽  
Vol 898 ◽  
pp. 2101-2106
Author(s):  
Zhong Yang Wang ◽  
Xin Yan Li ◽  
Run Hua Fan ◽  
Pei Tao Xie ◽  
Kai Sun ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Carbon Fibers ◽  
Percolation Theory ◽  
High Dielectric Constant ◽  
Volume Fraction ◽  
Dielectric Behavior ◽  
Lower Volume Fraction ◽  
Lower Volume ◽  
High Dielectric

Conductor–insulator composites have been extensive researched for high dielectric constant. Most of them concentrated on metal polymers or metal ceramics. Barium titanate–carbon fibers composites were prepared by using a solid state reaction process with carbon fibers contents ranging from7 vol% to 23 vol%. Due to the high-aspect-ratio of carbon fiber, it was easy to produce a conducting network at much lower volume fraction. FESEM images illustrated that the carbon fibers influenced the densification and microstructure of the ceramics. Besides, addition of carbon fibers led to increase in dielectric permittivity, also had effects on the dielectric loss and ac conductivity. The dielectric and conductivity properties as a function of carbon fibers volume fraction were explained by the percolation theory.

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.

Dielectric behavior of a flexible three-phase polyimide/BaTiO3/multi-walled carbon nanotube composite film

2016 ◽  
Vol 09 (01) ◽  
pp. 1650006 ◽  
Author(s):  
Junli Wang ◽  
Shengli Qi ◽  
Yiyi Sun ◽  
Guofeng Tian ◽  
Dezhen Wu
Keyword(s):  
Composite Film ◽  
Volume Fraction ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Dielectric Behavior ◽  
Low Dielectric ◽  
Three Phase ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
High Dielectric

A three-phase composite film was produced by inserting multi-walled carbon nanotubes (MWCNTs) and BaTiO3 nanoparticles into polyimide (PI). The combination of in-situ polymerization and water-based preparation involved in the experiment ensured fillers’ homogeneous dispersion in the matrix, which led to flexible shape of the composite films. The dielectric properties of composite films as a function of the frequency and the volume fraction of MWCNTs were studied. Such composite film displayed a high dielectric constant (314.07), low dielectric loss and excellent flexibility at 100[Formula: see text]Hz in the neighborhood of percolation threshold (9.02 vol%) owing to the special microcapacitor structure. The experimental results were highly consistent with the power law of percolation theory.

scholarly journals Investigating the dielectric properties of barium titanate nanocomposites using transmission electron microscopy image processing

MRS Advances ◽  
2021 ◽  
Author(s):  
Gio Ferro ◽  
Dithi Ganjam ◽  
Maia Gibson ◽  
Katie Partington ◽  
Akshay Trikha ◽  
...  
Keyword(s):  
Image Processing ◽  
Dielectric Constant ◽  
Energy Storage ◽  
Barium Titanate ◽  
Computational Models ◽  
Transmission Electron Microscopy Image ◽  
Dielectric Behavior ◽  
Dielectric Constants ◽  
Transmission Electron ◽  
High Dielectric

AbstractBarium titanate (BTO) is a ferroelectric perovskite material used in energy storage applications because of its high dielectric constant. A previous study showed that the dielectric constant for BTO nanoparticles drastically increases to over 15,000 at a particle size of 70 nm. This result is highly contested, but its implications to energy storage motivated our investigation into the dielectric constants of BTO nanoparticles that are incorporated into a polymer matrix. We developed a novel method of using image processing techniques on transmission electron microscope images of BTO-polymer nanocomposites. Data on the positions, shapes, sizes, and orientations of BTO nanoparticles were used to build more realistic computational models that simulate the dielectric behavior of the nanocomposites. Here, we investigate the relationship between regions of enhanced electric field and the composite dielectric constant.

scholarly journals Photo Actuation Performance of Nanotube Sheet Incorporated Azobenzene Crosslinked Liquid Crystalline Polymer Nanocomposite

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 735 ◽  
Author(s):  
Meng Bi ◽  
Yifan He ◽  
Yuchang Wang ◽  
Wenlong Yang ◽  
Ban Qin ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Microelectromechanical Systems ◽  
In Situ Polymerization ◽  
Uv Light ◽  
Polymer Network ◽  
Polymer Nanocomposite ◽  
Crystalline Polymer ◽  
Light Irradiation ◽  
Nanocomposite Films ◽  
Biological Engineering

Crosslinked liquid crystalline polymers (CLCPs) containing azobenzene (AZO-CLCPs) are a type of promising material due to their significance in the design of light-driven smart actuators. Developing AZO-CLCP composites by incorporating AZO-CLCPs with other materials is an effective way of enhancing their practicability. Herein, we report an AZO-CLCP/CNT nanocomposite prepared by the in situ polymerization of diacrylates containing azobenzene chromophores on carbon nanotube (CNT) sheets. The liquid crystal phase structure of CLCP matrix was evidenced by the two-dimensional X-ray scattering. The prepared pure AZO-CLCP films and AZO-CLCP/CNT nanocomposite films demonstrated strong reversible photo-triggered deformation under the irradiation of UV light at 366 nm of wavelength, as a result of photo-induced isomerization of azobenzene moieties in the polymer network. But compared to pure AZO-CLCP films, the AZO-CLCP/CNT nanocomposite films could much more rapidly return to their initial shapes after the UV light irradiation was removed due to the elasticity effect of CNT sheets. The deformation behavior of AZO-CLCP/CNT nanocomposite films under the light irradiation was also different from that of the pure AZO-CLCP films due to the interfacial interaction between a polymer network and CNT sheet. Furthermore, incorporation of a CNT sheet remarkably increased the mechanical strength and robustness of the material. We also used this AZO-CLCP/CNT nanocomposite as a microvalve membrane actuator, which can be controlled by light, for a conceptual device of a microfluidic system. The results showed that this AZO-CLCP/CNT nanocomposite may have great potential in smart actuator applications for biological engineering, medical treatment, environment detection and microelectromechanical systems (MEMS), etc.

Boosted dielectric performance of organic‐inorganic nanocomposites based on BaTiO3 via 2D TiO2 templates

2021 ◽  
Author(s):  
Se Yeon Park ◽  
Moonjeong Jang ◽  
Wooseok Song ◽  
Sun Sook Lee ◽  
Dae Ho Yoon ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Polymer Materials ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
Dielectric Performance ◽  
Inorganic Nanocomposites ◽  
Ceramic Fillers ◽  
High Dielectric ◽  
Nanocomposite Dielectric

Abstract Organic-inorganic hybrid dielectrics composed of nanoscale ceramic fillers in polymer matrices have attracted considerable attention because they can overcome the inherent limitations such as the low dielectric constant, high dielectric loss, and low film density associated with mechanically flexible pristine polymer materials. Barium titanate (BaTiO3), a representative perovskite-based material with a high permittivity, is suitable for applications as nanofillers in nanocomposite dielectrics. X-ray diffraction combined with Raman analysis suggest that a two-step hydrothermal synthesis, which uses synthesized TiO2 nanosheets as a template, is an effective method for the synthesis of pure BaTiO3 nanoparticles compared with other methods. Ultrasonic treatment is employed to disperse BaTiO3 nanoparticles with different concentrations in polyvinyl alcohol (PVA) polymer, and the dielectric performance of the nanocomposite films has been examined. In this study, 20 wt% BaTiO3-PVA nanocomposite dielectric showed superior capacitance and dielectric constant performance, i.e., five times higher than that of the pristine PVA.

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