scholarly journals Laser Ablation-Assisted Synthesis of Poly (Vinylidene Fluoride)/Au Nanocomposites: Crystalline Phase and Micromechanical Finite Element Analysis

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2630 ◽  
Author(s):  
Yasin Orooji ◽  
Babak Jaleh ◽  
Fatemeh Homayouni ◽  
Parisa Fakhri ◽  
Mohammad Kashfi ◽  
...  

In this research, piezoelectric polymer nanocomposite films were produced through solution mixing of laser-synthesized Au nanoparticles in poly (vinylidene fluoride) (PVDF) matrix. Synthetization of Au nanoparticles was carried out by laser ablation in N-methyle-2-pyrrolidene (NMP), and then it was added to PVDF: NMP solution with three different concentrations. Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were carried out in order to study the crystalline structure of the nanocomposite films. Results revealed that a remakable change in crystalline polymorph of PVDF has occurred by embedding Au nanoparticles into the polymer matrix. The polar phase fraction was greatly improved by increasing the loading content of Au nanoparticle. Thermogravimetric analysis (TGA) showed that the nanocomposite films are more resistant to high temperature and thermal degradation. An increment in dielectric constant was noticed by increasing the concentration of Au nanoparticles through capacitance, inductance, and resistance (LCR) measurement. Moreover, the mechanical properties of nanocomposites were numerically anticipated by a finite element based micromechanical model. The results reveal an enhancement in both tensile and shear moduli.

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2064
Author(s):  
Pornsawan Kum-onsa ◽  
Narong Chanlek ◽  
Jedsada Manyam ◽  
Prasit Thongbai ◽  
Viyada Harnchana ◽  
...  

Flexible dielectric polymer composites have been of great interest as embedded capacitor materials in the electronic industry. However, a polymer composite has a low relative dielectric permittivity (ε′ < 100), while its dielectric loss tangent is generally large (tanδ > 0.1). In this study, we fabricate a novel, high-permittivity polymer nanocomposite system with a low tanδ. The nanocomposite system comprises poly(vinylidene fluoride) (PVDF) co-filled with Au nanoparticles and semiconducting TiO2 nanorods (TNRs) that contain Ti3+ ions. To homogeneously disperse the conductive Au phase, the TNR surface was decorated with Au-NPs ~10–20 nm in size (Au-TNRs) using a modified Turkevich method. The polar β-PVDF phase was enhanced by the incorporation of the Au nanoparticles, partially contributing to the enhanced ε′ value. The introduction of the Au-TNRs in the PVDF matrix provided three-phase Au-TNR/PVDF nanocomposites with excellent dielectric properties (i.e., high ε′ ≈ 157 and low tanδ ≈ 0.05 at 1.8 vol% of Au and 47.4 vol% of TNRs). The ε′ of the three-phase Au-TNR/PVDF composite is ~2.4-times higher than that of the two-phase TNR/PVDF composite, clearly highlighting the primary contribution of the Au nanoparticles at similar filler loadings. The volume fraction dependence of ε′ is in close agreement with the effective medium percolation theory model. The significant enhancement in ε′ was primarily caused by interfacial polarization at the PVDF–conducting Au nanoparticle and PVDF–semiconducting TNR interfaces, as well as by the induced β-PVDF phase. A low tanδ was achieved due to the inhibited conducting pathway formed by direct Au nanoparticle contact.


2018 ◽  
Vol 6 (30) ◽  
pp. 14614-14622 ◽  
Author(s):  
Zhongbin Pan ◽  
Lingmin Yao ◽  
Guanglong Ge ◽  
Bo Shen ◽  
Jiwei Zhai

Nanocomposite films loaded with small NaNbO3 nanowires exhibit a high discharge energy density of 12.26 J cm−3 at 410 MV m−1, superior power density of 2.01 MW cm−3, and ultra-fast discharge speed of 146 ns.


2020 ◽  
Vol 44 (34) ◽  
pp. 14578-14591
Author(s):  
Akash M. Chandran ◽  
S. Varun ◽  
Prasanna Kumar S. Mural

In the present study, we report a simple fabrication method for poly(vinylidene fluoride) PVDF/MWCNT flexible nanocomposite films with a boosted electroactive phase that enhanced the dielectric and piezoelectric properties.


2011 ◽  
Vol 87 ◽  
pp. 106-112 ◽  
Author(s):  
Amiri Asfarjani Alireza ◽  
Adibnazari Sayid ◽  
Reza Kashyzadeh Kazem

Fibrous composites are finding more and more applications in aerospace, automotive, and naval industries. They have high stiffness and strength to weight ratio and good rating in regards to life time fatigue. Investigating mechanical behavior under dynamic loads to replace this material is very important. In the present article, investigate Fatigue of Unidirectional Fibrous Composites by using finite element analysis. So, to achieve this purpose Firstly, modeling fiber and matrix in separate case and simulated semi actual conditions, attained S-N curve of fiber and matrix and after that by using micromechanical model of combination fiber and matrix can approach S-N curve of Unidirectional Fibrous Composites. Finally, Comparisons of the finite element analysis of Ansys and the experimental predictions indicate based on three point bending fatigue testing that the results are satisfactorily in good agreement with each other which approves the power law assumption in the model.


2005 ◽  
Vol 20 (9) ◽  
pp. 2516-2522 ◽  
Author(s):  
George Sirinakis ◽  
Rezina Siddique ◽  
Christos Monokroussos ◽  
Michael A. Carpenter ◽  
Alain E. Kaloyeros

Nanocomposite films consisting of gold nanoparticles embedded in an yttria stabilized zirconia (YSZ) matrix were synthesized at room temperature by radio-frequency co-sputtering from YSZ and Au targets at a 5 mTorr working pressure. The films were subsequently annealed for 2 h in 1 atm argon, with the annealing temperature varied from 600 to 1000 °C in steps of 100 °C. The composition, microstructure, and optical properties of the films were characterized as a function of annealing temperature by Rutherford backscattering spectrometry, scanning electron microscopy, Auger electron spectroscopy, x-ray diffraction, and absorption spectroscopy. An optical absorption band due to the surface plasmon resonance (SPR) of the Au nanoparticles was observed around a wavelength of 600 nm. Furthermore, the SPR band full width at half-maximum exhibited an inverse linear dependence on the radius of the Au nanoparticle, with a slope parameter A = 0.18, indicating a weak interaction between the YSZ matrix and the Au nanoparticles. The experimentally observed SPR dependence on nanoparticle size is discussed within the context of the Mie theory and its size-dependent optical constants.


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