Preparation of Barium Titanate/Polyimide Composite Film and its Dielectric Properties

2013 ◽  
Vol 815 ◽  
pp. 93-98 ◽  
Author(s):  
Ya Jun Wang ◽  
Xiao Juan Wu

Polyimide (PI) was chosen as the matrix of the composites, barium titanate/polyimide (BT/PI) nanocomposite films were prepared with in-situ polymerization. The morphology of the samples was obtained by SEM. The factors affecting the dielectric properties are discussed. When the mass fraction of BT is 70%, the dielectric constant will be 19.32, and loss 0.00254 (at 103 Hz). The optimal solvent content and ultrasonic time were 9.2 ml and 30 min respectively. TG analysis shows that the film is stable below 500°C. The AC breakdown strength were 42 MV·m-1 and 64 MV·m-1 for 70% BT/PI and 60% BT/PI respectively, and corresponding energy storage density were 0.17 J·cm-3 and 0.30 J·cm-3 respectively.

2014 ◽  
Vol 908 ◽  
pp. 63-66
Author(s):  
Ya Jun Wang ◽  
Xiao Juan Wu ◽  
Chang Gen Feng

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.


2014 ◽  
Vol 981 ◽  
pp. 914-917
Author(s):  
Guang You Li ◽  
Jing Hua Yin ◽  
Lei Yao ◽  
Xing Zhao

Polyimide-based (PI) nanocomposites possess excellent electrical and thermal performance, widely used in inverter motor. In the paper using different particle sizes made polyimide/titania (PI/TiO2) nanocomposite films in situ polymerization, including 20nm A series and 50nm B series. The results shows that A series have a larger specific surface, combination of the film and matrix is closer without affecting the imidization of PI, and there is a clear interface layer and the structure is more stable. According to the time of corona-resistant A Series films is significantly longer than B Series films, especially the A series films with 15% of which corona-resistant time is 15h, five times than the pure PI. By both SAXS and XRD particle size in the matrix can be calculated, proving small particles can be better combination of the matrix of PI, increasing the number of traps, more effectively cutting off charge corrosion and making corona resistance greater performance.


2010 ◽  
Vol 25 (12) ◽  
pp. 2384-2391 ◽  
Author(s):  
Jun-Wei Zha ◽  
Ben-Hui Fan ◽  
Zhi-Min Dang ◽  
Sheng-Tao Li ◽  
George Chen

Polyimide (PI)-matrix composite films containing inorganic nanoparticles (nano-Al2O3 and nano-TiO2) have been fabricated. A proposed model is used to explain different structures of the (Al2O3–TiO2)/PI (ATP) films synthesized by employing in situ polymerization. Dependences of dielectric permittivities of the ATP films on frequency and temperature were studied. Results show the breakdown strength of the films decreases with prolonging the corona aging time. The incorporation of the nano-Al2O3 and nano-TiO2 particles significantly improves the corona resistance of the films. The corona aging also influences the infrared absorbance, the glass transition temperature (Tg), and loss factor (tanδ) of the ATP films.


2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...


2019 ◽  
Vol 3 (4) ◽  
pp. 726-736 ◽  
Author(s):  
Longhui Zheng ◽  
Li Yuan ◽  
Guozheng Liang ◽  
Aijuan Gu

High-k composites with temperature-stable dielectric properties and low dielectric loss obtained through building a network with in situ-doped barium titanate foam.


RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 44749-44755 ◽  
Author(s):  
Yun-Hui Wu ◽  
Jun-Wei Zha ◽  
Zhi-Qiang Yao ◽  
Fang Sun ◽  
Robert K. Y. Li ◽  
...  

PI composite films with electrospun BT fibers were fabricated using the in situ dispersion polymerization method. The microstructures, thermal and dielectric properties of the BT fibers and composite films were investigated.


2020 ◽  
Vol 10 (23) ◽  
pp. 8740
Author(s):  
Hongsub Jee ◽  
Hyeong-Sub Oh ◽  
Jaehyeong Lee

Poly(fluorene-alt-benzothiadiazole) (PFBT) is a promising chiral polymer for use in metamaterials and other photonic applications, due to its large chiral optical activity at visible wavelengths. However, its usages are very limited, since it is not readily patternable into microstructures and challenging to apply to applications. In this paper, we demonstrate photo patterning of chiral PFBT/Achiral SU-8 photoresist to produce high quality structures while retaining the extraordinary chiral optical activity of our previously-reported PFBT/SU8 nanocomposite films. The ability to produce cleanly patterned microfeatures with high chirality may enable wider use of PFBT in chiral metamaterials and other photonic applications.


2020 ◽  
Vol 4 (3) ◽  
pp. 87
Author(s):  
Francisco J. González ◽  
Andreina Montesinos ◽  
Javier Araujo-Morera ◽  
Raquel Verdejo ◽  
Mario Hoyos

Composite materials of poly(3,4-ethylenedioxythiophene) (PEDOT)/activated carbon (AC) were prepared by ‘in-situ’ polymerization and subsequently deposited by spray-coating onto a flexible electrolyte prepared in our laboratories. Two activated carbons were tested: a commercial activated carbon and a lab-made activated carbon from brewer’s spent grain (BSG). The porous and spongy structure of the composite increased the specific surface area, which helps to enhance the energy storage density. This procedure to develop conductive composite materials using AC prepared from biowaste has the potential to be implemented for the preparation of polymer-based conductive inks for further applications as electrodes in pseudocapacitors.


2008 ◽  
Vol 587-588 ◽  
pp. 212-216 ◽  
Author(s):  
Magdalena Jurczyk-Kowalska ◽  
Joanna Ryszkowska

Carboxyalumoxanes have been incorporated into a polyurethane matrix by in situ polymerization. The filler was dispersed in the polyurethane matrix by either both ultrasonic and mechanical mixing or by mechanical mixing alone. The physico-mechanical properties of the composites have been characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Using ultrasound improves the degree of dispersion of the fillers in the matrix, but it also causes changes in the structure of the polyurethane matrix.


2015 ◽  
Vol 727-728 ◽  
pp. 38-41
Author(s):  
Hai Tao Zhao ◽  
Rui Ping Liu ◽  
Qiao Wang ◽  
Kai Xin Yang

TiO2/PPy composite was prepared by in situ polymerization of pyrrole on TiO2 microparticles. The results show that PPy chains have ordered arrangement to some extent. The average diameter of PPy microspheres is roughly 500 nm. TiO2 microspheres obtained are anatase-type. PPy/TiO2 composite particles are similar to spheres and there is some reunite phenomenon. The tanδe value for TiO2/PPy composite is higher than PPy in the frequency range of 8.2-12.4 GHz and it has achieved a maximum of 0.57 at 11.9 GHz.


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