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Feng, Zunpeng, Yanan Hao, Jiameng Zhang, Jing Qin, Limin Guo i Ke Bi. "Dielectric Properties of Two-Dimensional Bi2Se3 Hexagonal Nanoplates Modified PVDF Nanocomposites". Advances in Polymer Technology 2019 (3.07.2019): 1–8. http://dx.doi.org/10.1155/2019/8720678.
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Topological insulator two-dimensional (2D) Bi2Se3 hexagonal nanoplates, which are highly insulating in the bulk and have a conductive topological surface state, have been prepared via an “EG- (ethylene glycol-) sol” method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Bi2Se3/PVDF (polyvinylidene fluoride) nanocomposites with various Bi2Se3 contents have been fabricated by a tape-casting method. The microstructure and dielectric performance of the Bi2Se3/PVDF nanocomposites are studied. The dielectric constant of the dense nanocomposite films keeps a relatively low value of about 16 when the Bi2Se3 content is lower than 12 vol.% then suddenly increases to 36 with a critical Bi2Se3 content of 13 vol.% due to the percolation effect of the large aspect ratio of the 2D Bi2Se3 nanoplates. The study of the Bi2Se3/PVDF nanocomposite system is conducive to the exploration of high-performance dielectrics.
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Li, Qi, Feihua Liu, Tiannan Yang, Matthew R. Gadinski, Guangzu Zhang, Long-Qing Chen i Qing Wang. "Sandwich-structured polymer nanocomposites with high energy density and great charge–discharge efficiency at elevated temperatures". Proceedings of the National Academy of Sciences 113, nr 36 (22.08.2016): 9995–10000. http://dx.doi.org/10.1073/pnas.1603792113.
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The demand for a new generation of high-temperature dielectric materials toward capacitive energy storage has been driven by the rise of high-power applications such as electric vehicles, aircraft, and pulsed power systems where the power electronics are exposed to elevated temperatures. Polymer dielectrics are characterized by being lightweight, and their scalability, mechanical flexibility, high dielectric strength, and great reliability, but they are limited to relatively low operating temperatures. The existing polymer nanocomposite-based dielectrics with a limited energy density at high temperatures also present a major barrier to achieving significant reductions in size and weight of energy devices. Here we report the sandwich structures as an efficient route to high-temperature dielectric polymer nanocomposites that simultaneously possess high dielectric constant and low dielectric loss. In contrast to the conventional single-layer configuration, the rationally designed sandwich-structured polymer nanocomposites are capable of integrating the complementary properties of spatially organized multicomponents in a synergistic fashion to raise dielectric constant, and subsequently greatly improve discharged energy densities while retaining low loss and high charge–discharge efficiency at elevated temperatures. At 150 °C and 200 MV m−1, an operating condition toward electric vehicle applications, the sandwich-structured polymer nanocomposites outperform the state-of-the-art polymer-based dielectrics in terms of energy density, power density, charge–discharge efficiency, and cyclability. The excellent dielectric and capacitive properties of the polymer nanocomposites may pave a way for widespread applications in modern electronics and power modules where harsh operating conditions are present.
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Yang, Jiaming, Congji Liu, Changji Zheng, Hong Zhao, Xuan Wang i Mingze Gao. "Effects of Interfacial Charge on the DC Dielectric Properties of Nanocomposites". Journal of Nanomaterials 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/2935202.
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The interfacial charge phenomenon of MgO/low-density polyethylene (LDPE) and SiO2/LDPE nanocomposites was measured by synchrotron radiation small-angle X-ray scattering. Based on the Porod theory, the Porod curve of SiO2/LDPE nanocomposite shows negative divergence but the LDPE and MgO/LDPE do not, which reveals that interfacial charge may exist in the SiO2/LDPE nanocomposite. The DC dielectric properties of the nanocomposites are closely related to the interfacial charge. Experimental results show that the SiO2/LDPE nanocomposite has lower DC conductivity, less space charge, and higher DC breakdown strength than the MgO/LDPE nanocomposite. It is thought that the interfacial charge has a positive effect on the DC dielectric performance of nanocomposites, and the mechanism could be attributed to the scattering effects of the interfacial charge on the carrier migration. There is no obvious interfacial charge in the MgO/LDPE nanocomposite, but it still has excellent DC dielectric properties compared with LDPE, which indicates that the interfacial charge is not the only factor affecting the dielectric properties; the dipole interface layer and the reduction of free volume can also inhibit the migration of carriers and decrease electrons free path, improving the dielectric performance.
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Polsterova, Helena. "Dielectric Properties of Nanocomposites Based on Epoxy Resin". ECS Transactions 105, nr 1 (30.11.2021): 461–66. http://dx.doi.org/10.1149/10501.0461ecst.
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Nanocomposites are subject of research in many fields of science. Electrical technology focused on the study of electrical properties of nanocomposites including breakdown strength, relative permittivity, resistivity and other. This paper describes the results of measurement of electrical parameters of a nanocomposite at various temperatures. The nanocomposite matrix was casting epoxy resin and nanoparticles were made of TiO2 powder at different concentrations.
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Li, Yan Xia, Jin Long Xie, Zhen Ming Chu, Xu Sheng Wang i Xi Yao. "Dielectric and Energy Storage Properties of Polyvinylidene Fluoride/Barium Titanate Nanocomposites". Advanced Materials Research 833 (listopad 2013): 365–69. http://dx.doi.org/10.4028/www.scientific.net/amr.833.365.
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The combination of nanoparticles with high relative permittivity and polymers with high dielectric strength offers a potential to obtain processable nanocomposites with high dielectric performance. In this work, polyvinylidene fluoride (PVDF)-barium titanate (BT) nanocomposites were prepared by spin-coating technique. The surface of BT nanoparticles was treated by titanate coupling agent NDZ101. The dielectric and energy storage properties of the system were studied as a function of BT content. The experimental results showed that the dielectric constant of the nanocomposites increased with the increase of BT content. Although pure PVDF material has the strongest dielectric breakdown strength, the discharged energy storage density Ue of the nanocomposites was greatly improved from 2.8 J/cm3 in pure PVDF film to 6.2 J/cm3 in PVDF/20 wt% BT film; due to larger polarization of the nanocomposite.
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Pattanshetti, Virappa Virupaxappa, G. M. Shashidhara i Mysore Guruswamy Veena. "Dielectric and thermal properties of magnesium oxide/poly(aryl ether ketone) nanocomposites". Science and Engineering of Composite Materials 25, nr 5 (25.09.2018): 915–25. http://dx.doi.org/10.1515/secm-2016-0273.
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AbstractIn the present study, dielectric and thermal properties of poly(aryl ether ketone) (PAEK)-nanocomposites with varying weight percentage of magnesium oxide (MgO) have been reported. The thermal properties of PAEK/MgO nanocomposites were studied using differential scanning calorimetry, thermogravimetric analysis, thermo-mechanical analysis and thermal conductivity. Transmission electron microscopy of the developed nanocomposites shows agglomerate-free dispersion of MgO nanoparticles in PAEK matrix. From the dielectric properties, dielectric constant of 13 was achieved for 10 wt% PAEK/MgO nanocomposite at 230°C. Further, minimum tan δ and maximum volume resistivity were found for 10 wt% PAEK/MgO nanocomposite. Data from thermal studies indicate that the incorporation of MgO into PAEK significantly enhanced the glass transition temperature and slightly deteriorated the thermal stability, char yield, and flame-retardant properties. Also, highest thermal conductivity and lowest coefficient of thermal expansion were achieved at 10 wt% of the MgO content. An excellent combination of both dielectric and thermal properties of the PAEK/MgO nanocomposites developed in the present study finds its potential application in microelectronics and electrical insulation in power equipments.
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Alam, Rabeya Binta, Md Hasive Ahmad, S. F. U. Farhad i Muhammad Rakibul Islam. "Significantly improved dielectric performance of bio-inspired gelatin/single-walled carbon nanotube nanocomposite". Journal of Applied Physics 131, nr 12 (28.03.2022): 124103. http://dx.doi.org/10.1063/5.0077896.
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In this study, the dielectric properties of gelatin/single-walled carbon nanotube (Gel/SWCNT) nanocomposite were evaluated. The nanocomposites were synthesized by a simple solution casting method. The electron transport properties of the nanocomposites were studied by the dielectric and impedance spectroscopy techniques. A dielectric constant as high as 104 and a loss tangent of 0.91 were obtained for the Gel/SWCNT nanocomposite material at 100 Hz. The dielectric permittivity data of the nanocomposites were fitted by the modified Cole–Cole model to estimate the dielectric strength and the relaxation time. The addition of SWCNT into the gelatin reduces the relaxation time of the nanocomposite from 3.03 to 1.01 μs. The complex impedance spectra analyses show an increase in alternating current conductivity due to the incorporation of SWCNT and can be attributed to the change in bulk resistance together with a reduction in relaxation time of the nanocomposite. A quantitative analysis from the fitting of the Cole–Cole plot also reveals that the incorporation of SWCNT into the nanocomposite decreases the grain boundary resistance from 16 950 to 53 kΩ and increases the capacitive element from 67 to 275 nF. The mechanism behind the improved dielectric performance of the Gel/SWCNT nanocomposites has been elucidated in this study.
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Dang, Yue-Mao, Ming-Sheng Zheng i Jun-Wei Zha. "Improvements of dielectric properties and energy storage performances in BaTiO3/PVDF nanocomposites by employing a thermal treatment process". Journal of Advanced Dielectrics 08, nr 06 (grudzień 2018): 1850043. http://dx.doi.org/10.1142/s2010135x18500431.
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The influence of thermal treatment on the dielectric properties and energy storage performances of a classical dielectric nanocomposite system (barium titanate/polyvinylidene fluoride PVDF) was discussed systematically. The results demonstrated that the permittivity of thermal treated nanocomposites increased and dielectric loss decreased compared with the untreated system. In addition, the energy density was also greatly improved due to the inclined residual polarization. For example, the energy density of the treated nanocomposite with 50[Formula: see text]vol.% nanofillers was 3.14 times higher than the untreated nanocomposite at 50[Formula: see text]MV/m. Moreover, the charge–discharge efficiency was also promoted from 6.36% to 56.89%. According to the viewpoint of microstructure, the improvement of the dielectric and energy storage properties would be ascribed to the suppression on void defects in the interphase of dielectric nanocomposite by employing the thermal treatment process. Finally, thermal treatment turns out to be a simple and an effective method to improve the dielectric performances and energy storage properties in the dielectric nanocomposites.
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Niaz, N. A., A. Shakoor, F. Hussain, M. Iqbal, N. R. Khalid, M. K. Saleem, N. Anwar i J. Ahmad. "Structural and electronic properties of PANI-ZnO-TiO2 nanocomposite". Journal of Ovonic Research 18, nr 5 (3.11.2022): 713–22. http://dx.doi.org/10.15251/jor.2022.185.713.
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The nanocomposites of doped Polyaniline (PANI) with ZnO-TiO2 nanoparticles have been prepared by in-situ polymerization method. The structural properties of synthesized PANI and PANI/ZnO-TiO2 were studied by X-ray diffraction (XRD) analysis. XRD pattern show that PANI is intercalated into the layers of ZnO-TiO2 successfully and thus the degree of crystallinity increases due to crystalline nature of ZnO-TiO2. FTIR analysis indicated that there is a strong interaction between ZnO-TiO2 nanoparticles and PANI. Electronic properties (Dielectric and Conductivity) of PANI and PANI/ZnO-TiO2 nanocomposite have been investigated between frequency ranges from 20Hz to 01MHz, higher dielectric constants and dielectric losses of PANI/ZnO-TiO2 nanocomposites were found. As the content of ZnO-TiO2 increased, the dielectric constant and loss also increased. The value of dielectric constant for all samples is very high at low frequency but decreases with increase in frequency. Synthesis of PANI/ZnO-TiO2 nanocomposite materials with a large dielectric constant is promising for charge storage devices applications
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Novruzova, A. A. "STRUCTURE AND ELECTROPHYSICAL PROPERTIES OF PVDF+PbS/CdS NANOCOMPOSITES". NNC RK Bulletin, nr 2 (17.10.2021): 53–56. http://dx.doi.org/10.52676/1729-7885-2021-2-53-56.
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In the given paper were investigated structure and electrophysical properties of PVDF+PbS/CdS nanocomposites. Distribution and the size of PbS and CdS nanoparticles in the polymer matrix has been studied by scanning electron microscopy (JEOL JSM-7600 F). The structure of the nanocomposite samples was investigated by the X-ray diffraction spectroscopy. The dependence of dielectric permittivity at frequency and temperature was investigated. It was shown that the dielectric permittivity of PVDF+PbS/CdS nanocomposite samples was increase in small nanoparticles content. Further increase in the concentration of the filler leads to decrease in the dielectric permittivity. The subsequent decrease in dielectric permittivity at higher nanoparticles content can be explained by the increase in defects in the structure of the nanocomposite.
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Min, Daomin, Chenyu Yan, Rui Mi, Chao Ma, Yin Huang, Shengtao Li, Qingzhou Wu i Zhaoliang Xing. "Carrier Transport and Molecular Displacement Modulated dc Electrical Breakdown of Polypropylene Nanocomposites". Polymers 10, nr 11 (30.10.2018): 1207. http://dx.doi.org/10.3390/polym10111207.
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Dielectric energy storage capacitors have advantages such as ultra-high power density, extremely fast charge and discharge speed, long service lifespan and are significant for pulsed power system, smart power grid, and power electronics. Polypropylene (PP) is one of the most widely used dielectric materials for dielectric energy storage capacitors. It is of interest to investigate how to improve its electrical breakdown strength by nanodoping and the influencing mechanism of nanodoping on the electrical breakdown properties of polymer nanocomposites. PP/Al2O3 nanocomposite dielectric materials with various weight fraction of nanoparticles are fabricated by melt-blending and hot-pressing methods. Thermally stimulated current, surface potential decay, and dc electrical breakdown experiments show that deep trap properties and associated molecular chain motion are changed by incorporating nanofillers into polymer matrix, resulting in the variations in conductivity and dc electrical breakdown field of nanocomposite dielectrics. Then, a charge transport and molecular displacement modulated electrical breakdown model is utilized to simulate the dc electrical breakdown behavior. It is found that isolated interfacial regions formed in nanocomposite dielectrics at relatively low loadings reduce the effective carrier mobility and strengthen the interaction between molecular chains, hindering the transport of charges and the displacement of molecular chains with occupied deep traps. Accordingly, the electrical breakdown strength is enhanced at relatively low loadings. Interfacial regions may overlap in nanocomposite dielectrics at relatively high loadings so that the effective carrier mobility decreases and the interaction between molecular chains may be weakened. Consequently, the molecular motion is accelerated by electric force, leading to the decrease in electrical breakdown strength. The experiments and simulations reveals that the influence of nanodoping on dc electrical breakdown properties may origin from the changes in the charge transport and molecular displacement characteristics caused by interfacial regions in nanocomposite dielectrics.
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Liu, Tian, Weston Wood, Bin Li, Brooks Lively i Wei-Hong Zhong. "Electrical and dielectric sensitivities to thermal processes in carbon nanofiber/high-density polyethylene composites". Science and Engineering of Composite Materials 18, nr 1-2 (1.06.2011): 51–60. http://dx.doi.org/10.1515/secm.2011.007.
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AbstractOwing to the huge interface region existing in a polymer nanocomposite, the effects of thermal processes on properties of nanocomposites are much more complicated than in a pure polymer. It is therefore important to determine the effects of thermal processes on nanocomposites with different interfacial interactions between the nanofillers and the polymer matrix. It is also important to explore the performance changes for nanocomposites under elevated temperatures over pure polymers. In this investigation, we examined the correlation of thermal treatment with dielectric properties of carbon nanofiber (CNF) reinforced high-density polyethylene nanocomposites. The thermal treatment of specimens was conducted for up to 120 h at 87°C and 127°C. Then, alternating current (AC) conductivity and dielectric properties were tested after definite intervals of time. Their changing rates over treatment time were analyzed. The results revealed the approximate linear relationships of AC conductivity and dielectric constant vs. heating time. Modified CNF reinforced nanocomposites had less influence by the heating treatments exhibiting better thermal resistance. The change rates of AC conductivity σ and dielectric properties have higher sensitivity to the treatment at a higher temperature. This study provides potential for further research on application of electrical and dielectric signals to detect the effects of heating process on lifetime of polymeric materials.
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Kaur, Daljeet, Amardeep Bharti, Tripti Sharma i Charu Madhu. "Dielectric Properties of ZnO-Based Nanocomposites and Their Potential Applications". International Journal of Optics 2021 (22.07.2021): 1–20. http://dx.doi.org/10.1155/2021/9950202.
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Energy storage devices constitute one of the research areas in recent years. Capacitors are commonly used for the storage of electrical energy. The current research is focusing on not only the improvement in energy density but also the materials which are environment friendly. Polymer composites are known to be technically essential materials owing to their wide range of applications. Enormous research has been devoted to zinc oxide- (ZnO-) based polymer nanocomposites, due to their extraordinary dielectric properties. This review article presents a detailed study of the dielectric properties of ZnO-based nanocomposites. The dielectric constant study includes the effect of transition metals and rare earth metals as a dopant in ZnO. This review gives an insight into the mechanism responsible for the variation of dielectric constant in ZnO nanocomposites due to various factors like size of nanoparticles, thickness of the thin film, operating frequency, doping concentration, and atomic number. The observations have been summarized to convey the mechanism and structural changes involved in the ZnO nanocomposites to the researchers. The deployment of biodegradable nanocomposite materials is expected to open an innovative way for their outstanding electronic applications as storage materials.
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Hao, Y. N., K. Bi, S. O'Brien, X. X. Wang, J. Lombardi, F. Pearsall, W. L. Li, M. Lei, Y. Wu i L. T. Li. "Interface structure, precursor rheology and dielectric properties of BaTiO3/PVDF–hfp nanocomposite films prepared from colloidal perovskite nanoparticles". RSC Advances 7, nr 52 (2017): 32886–92. http://dx.doi.org/10.1039/c7ra03250a.
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A novel and greatly simplified strategy was developed to fabricate high-permittivity dielectric nanocomposites. Interface structure, precursor rheology and dielectric properties of the 0–3 BaTiO3/PVDF–hfp nanocomposite film were investigated.
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Yatsyshen, Valeriy, Irina Potapova i Vyacheslav Shipaev. "Polaritons in Nanocomposites of Metal Nanoparticles – Dielectric". NBI Technologies, nr 2 (październik 2019): 39–53. http://dx.doi.org/10.15688/nbit.jvolsu.2019.2.7.
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The article studies the main characteristics of surface polaritons in composite nanomaterials. The authors consider composite media such as noble metal nanoparticles randomly distributed in a transparent dielectric matrix and build dispersion curves of polaritons in such nanocomposites. The paper shows calculating optical parameters of the surface polariton for several values of the radius of metal nanoparticles and the nanocomposite filling parameter. The authors also present the calculations of the complex refractive index for polaritons in composites with nanoparticles of different metals. In addition, the authors find the dependences of the real and imaginary parts of the complex refractive index of the nanocomposite on the normalized frequency for membranes with different thicknesses and calculate real and imaginary parts of dielectric constant for waves in several metals. Besides, the article provides an overview of important stages in the study of surface electromagnetic waves. It shows that the variation of the structure materials, size and concentration of nanoparticles opens wide possibilities for controlling the optical properties of composite mediums and their practical application. The considered nanocomposites are artificially created media whose material parameters can be controlled. The first method consists in changing the relative volume of the nanoparticles filling of the dielectric matrix. The second method consists in changing the dielectric constant of the nanocomposite matrix. The authors emphasize that the dielectric constant of the nanocomposite in this case acquires resonant properties in contrast to the permeability of the nanoparticles themselves.
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NOH, HYUN-JI, SUNG-PILL NAM, SUNG-GAP LEE, BYEONG-LIB AHN, WOO-SIK WON, HYOUNG-GWAN WOO i SANG-MAN PARK. "ELECTRICAL AND MECHANICAL CHARACTERISTICS OF EPOXY-NANOCLAY COMPOSITE". Modern Physics Letters B 23, nr 31n32 (30.12.2009): 3925–30. http://dx.doi.org/10.1142/s0217984909022010.
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In this study, we investigated the effects of nanoclay additives on the electrical and mechanical properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resin. Epoxy-clay nanocomposites were synthesized using organically modified two montmorillonite clays (MMT) with different interlamellar spacing (31.5 Å and 18.5 Å). The electrical and mechanical properties of epoxy-clay nanocopomosites were measured with variation of the amount and type of clay. The nanocomposites were found to be homogenous materials although the nanocomposites still have clay aggregates with increasing nanoclay contents. The dielectric constant showed between 3.2 ~ 3.5 and the dielectric loss showed between 3.2 ~ 5.7% in all nanocoposites. The dielectric strength and tensile strength of the 5 wt% Cloisite 15A added epoxy-oclay nanocomposite were 23.9 kV/mm and 86.7 MPa, respectively.
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Ahangaran, Fatemeh, Ali Hassanzadeh, Sirous Nouri i Rasoul Esmaeely Neisiany. "Investigation of thermal and dielectric properties of Fe3O4/high-density polyethylene nanocomposites". Journal of Composite Materials 51, nr 28 (26.02.2017): 3923–29. http://dx.doi.org/10.1177/0021998317695419.
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High-density polyethylene nanocomposites containing Fe3O4 nanoparticles were prepared by employing melt mixing process. The amorphous Fe3O4 nanoparticles with average size about 50 nm were prepared by the conventional coprecipitation method from iron (ΙΙ and ΙΙΙ). Thermal and dielectric properties of high-density polyethylene and its nanocomposites were investigated via differential scanning calorimetry and electrochemical impedance spectroscopy. The crystalline structure of high-density polyethylene and Fe3O4/high-density polyethylene nanocomposite were studied by wide-angle X-ray diffraction, which confirmed orthorhombic crystalline structure. The results of thermal and dielectric analysis indicated that the addition of Fe3O4 nanoparticles to high-density polyethylene matrix leads to decreasing degree of crystallinity and improvement of dielectric constant.
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Cheng, Yujia, Guang Yu, Boyang Yu i Xiaohong Zhang. "The Research of Conductivity and Dielectric Properties of ZnO/LDPE Composites with Different Particles Size". Materials 13, nr 18 (17.09.2020): 4136. http://dx.doi.org/10.3390/ma13184136.
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Nanocomposites exhibit a high dielectric strength, whereas microcomposites exhibit a high thermal conductivity. In this study, good insulating materials were developed on the basis of the synergetic effect of micro- and nanoparticles, which were used as inorganic fillers. With a double-melting blend, nano-ZnO/low density polyethylene (LDPE), micro-ZnO/LDPE, and micro-nano-ZnO/LDPE composites were prepared, according to the scanning electron microscope test, polarization microscope test, conductivity test, breakdown test, and dielectric spectrum test, the dielectric property of micro-nano-ZnO/LDPE was explored. The SEM test results showed that by adding a suitable proportion of ZnO particles, the inorganic particles could disperse uniformly without reuniting. The PLM test results showed that the micro- and nano-ZnO particles adding decreased the crystal size. The arrangement was regular and tight. The macroscopic results showed that the mass fraction of nanoparticles and microparticles were 3% and 2%, the samples conductivity was the lowest. The breakdown field strength of the nanocomposites increased. The breakdown field strength of nanocomposites with 1%, 3%, and 5% nanoparticle contents were 5%, 15%, and 10% higher than that of pure LDPE. The addition of inorganic particles resulted in new polarization modes: Ionic displacement polarization and interfacial polarization. The ZnO/LDPE composites exhibited a higher dielectric constant and dielectric loss factor than pure LDPE. However, with the increasing frequency, it took considerable time to attain interfacial polarization in the nanocomposite and micro-nanocomposite, thus decreasing the dielectric constant.
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Wang, Shaojing, Peng Xu, Xiangyi Xu, Da Kang, Jie Chen, Zhe Li i Xingyi Huang. "Tailoring the Electrical Energy Storage Capability of Dielectric Polymer Nanocomposites via Engineering of the Host–Guest Interface by Phosphonic Acids". Molecules 27, nr 21 (25.10.2022): 7225. http://dx.doi.org/10.3390/molecules27217225.
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Polymer nanocomposites have attracted broad attention in the area of dielectric and energy storage. However, the electrical and chemical performance mismatch between inorganic nanoparticles and polymer leads to interfacial incompatibility. In this study, phosphonic acid molecules with different functional ligands were introduced to the surface of BaTiO3 (BT) nanoparticles to tune their surface properties and tailor the host–guest interaction between BT and poly(vinylideneflyoride-co-hexafluroro propylene) (P(VDF-HFP)). The dielectric properties and electrical energy storage capability of the nanocomposites were recorded by broadband dielectric spectroscopy and electric displacement measurements, respectively. The influence of the ligand length and polarity on the dielectric properties and electrical energy storage of the nanocomposites was documented. The nanocomposite with 5 vol% 2,3,4,5,6-pentafluorobenzyl phosphonic acid (PFBPA)-modified BT had the highest energy density of 12.8 J cm−3 at 400 MV m−1, i.e., a 187% enhancement in the electrical energy storage capability over the pure P(VDF-HFP). This enhancement can be attributed to the strong electron-withdrawing effect of the pentafluorobenzyl group of PFBPA, which changed the electronic nature of the polymer–particle interface. On the other hand, PFBPA improves the compatibility of the host–guest interface in the nanocomposites and decreases the electrical mismatch of the interface. These results provide new insights into the design and preparation of high-performance dielectric nanocomposites.
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Jeong, Jae, Hye Hwang, Dalsu Choi, Byung Ma, Jaehan Jung i Mincheol Chang. "Hybrid Polymer/Metal Oxide Thin Films for High Performance, Flexible Transistors". Micromachines 11, nr 3 (4.03.2020): 264. http://dx.doi.org/10.3390/mi11030264.
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Metal oxides (MOs) have garnered significant attention in a variety of research fields, particularly in flexible electronics such as wearable devices, due to their superior electronic properties. Meanwhile, polymers exhibit excellent mechanical properties such as flexibility and durability, besides enabling economic solution-based fabrication. Therefore, MO/polymer nanocomposites are excellent electronic materials for use in flexible electronics owing to the confluence of the merits of their components. In this article, we review recent developments in the synthesis and fabrication techniques for MO/polymer nanocomposite-based flexible transistors. In particular, representative MO/polymer nanocomposites for flexible and transparent channel layers and gate dielectrics are introduced and their electronic properties—such as mobilities and dielectric constant—are presented. Finally, we highlight the advances in interface engineering and its influence on device electronics.
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Sagar, Rohan, Akash Kumar, Rajesh Kumar Raghav i M. S. Gaur. "Investigations on Piezoelectric, Dielectric and Mechanical Properties of PVDF/PVC/GO Nanocomposites". ECS Journal of Solid State Science and Technology 12, nr 8 (1.08.2023): 083011. http://dx.doi.org/10.1149/2162-8777/aceeb4.
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In this study, the hardness of polyvinylidene fluoride (PVDF), PVC and PVDF/PVC/GO (2.0 wt%) was estimated using piezoelectric and dielectric properties. The structure morphology was analyzed by Fourier transform infrared spectroscopy (FTIR). With the help of the solution casting technique, GO nanofiller were incorporated into PVDF/PVC matrix to prepare nanocomposites. In the case of PVDF/PVC/GO nanocomposites (2.0 wt%), the d33 coefficient is comparatively higher. PVDF have lower dielectric constant, however, may be due to interfacial polarization occurring at the spherulites and at the polymer/filler interfaces. The achieved lower loss tangent (tanδ) for PVDF compared to PVDF/PVC and PVDF/PVC/GO (2.0 wt%) nanocomposites is attributed to PVDF highly insulating nature. The PVDF/PVC/GO (2.0 wt%) nanocomposite exhibited a d33 value of ∼26 pm V−1, which was significantly higher than pure PVDF and PVDF/PVC.
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Shao, Jiang, Le Zhou, Yuqi Chen, Xue Liu i Mingbo Ji. "Model-Based Dielectric Constant Estimation of Polymeric Nanocomposite". Polymers 14, nr 6 (11.03.2022): 1121. http://dx.doi.org/10.3390/polym14061121.
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The interphase region widely exists in polymer-based nanocomposites, which affects the dielectric properties of the nanocomposites. General models, such as the Knott model, are often used to predict the dielectric constant of nanocomposites, while the model does not take the existence of interphase into account, which leads to a large deviation between the predicted results and the experimental values. In this study, a developed Knott model is proposed by introducing the interphase region and appropriately assuming the properties of the interphase. The modeling results based on the developed model are in good agreement with the experimental data, which verifies the high accuracy of the development model. The influence of nanoparticle loading on the effective volume fraction is further studied. In addition, the effects of the polymer matrix, nanoparticles, interphase dielectric and thickness, nanoparticle size and volume fraction on the dielectric properties of the nanocomposites are also investigated. The results show that polymer matrix or nanoparticles with a high dielectric and thick interphase can effectively improve the dielectric properties of the materials. Small size nanoparticles with high concentrations are more conducive to improving the dielectric properties of the nanocomposites. This study demonstrates that the interphase properties have an important impact on the dielectric properties of nanocomposites, and the developed model is helpful to accurately predict the dielectric constant of polymer-based nanocomposites.
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Mohaimeed, Ameen alwan. "The Study the Influence of TiO2-Nanoparticles Doped in Polyvinyl Alcohol by Measuring Optical Properties of PVA Films". Iraqi Journal of Nanotechnology, nr 3 (14.10.2022): 59–70. http://dx.doi.org/10.47758/ijn.vi3.62.
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It was investigated how titanium dioxide nanoparticles affected the optical properties of polyvinyl alcohol. Polymer nanocomposites (PVA-TiO2) are created via stirring and casting. The results demonstrate that transmittance improves from 75% to 95% while titanium dioxide concentration enhances the absorbance of nanocomposites. Nanocomposite films made of PVA and TiO2 had reflectance values of 12 and 16 percent (weight percent=0.15 and 0.85%).The refractive index and coefficient of extinction rise with increasing density, and optical absorption and photon dispersion in the nanocomposite (PVA-TiO2) also rise as the concentration of titanium dioxide nanoparticles rises. Real dielectric (r) and imaginary dielectric I constants also rise as titanium dioxide nanoparticle concentration does. The results show that when the weight % of (TiO2) nanoparticles increased, the energy gap decreased from 3.32 to 2.23. Additionally, optical conductivity increased with the concentration of (TiO2) NPs. Nanocomposites of PVA and TiO2 are essential for optical applications.
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Kamarudin, Siti Noorhazirah, Kwan Yiew Lau, Chee Wei Tan i Kuan Yong Ching. "The Role of Silicon-Based Nanofillers and Polymer Crystallization on the Breakdown Behaviors of Polyethylene Blend Nanocomposites". Nano 15, nr 08 (sierpień 2020): 2050097. http://dx.doi.org/10.1142/s1793292020500976.
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Good breakdown strength is an important feature for the selection of dielectric materials, especially in high-voltage engineering. Although nanocomposites have been shown to possess many promising dielectric properties, the breakdown strength of nanocomposites is often found to be negatively affected. Recently, imposing nonisothermal crystallization processes on polyethylene blends has been demonstrated to be favorable for breakdown strength improvements of dielectric materials. In an attempt to increase nanocomposites’ voltage rating, this work reports on the effects of nonisothermal crystallization (fast, moderate and slow crystallizations) on the structure and dielectric properties of a polyethylene blend (PE) composed of 80% low density polyethylene and 20% high density polyethylene, added with silicon dioxide (SiO2) and silicon nitride (Si3N4) nanofillers. Through breakdown testing, the breakdown performance of Si3N4-based nanocomposites was better than SiO2-based nanocomposites. Since nanofiller dispersion within both nanocomposite systems was comparable, the enhanced breakdown performance of Si3N4-based nanocomposites is attributed to the surface chemistry of Si3N4 containing less hydroxyl groups than SiO2. Furthermore, the breakdown strength of SiO2-based nanocomposites and Si3N4-based nanocomposites improved, with the DC breakdown strength increasing by at least 12% when both the nanocomposites were subjected to moderate crystallization rather than fast and slow crystallizations. This is attributed to changes in the underlying molecular conformation of PE in addition to water-related effects. These results suggest that apart from changes in the nanofiller surface chemistry, changes in the underlying molecular conformation of polymers are also important to improve the breakdown performance of nanocomposites.
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Yang, Dandan, Haiping Xu i Wei Yu. "Comparative study on the dielectric properties of three polyvinylidene fluoride nanocomposites incorporated with carbon filler". Journal of Thermoplastic Composite Materials 31, nr 8 (5.10.2017): 1102–11. http://dx.doi.org/10.1177/0892705717734601.
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Poly(vinylidene fluoride) (PVDF)-carbon nanotube (CNT) composites with three different CNTs were prepared by a solution blending and hot-press method. The morphologies of nanocomposites were studied by scanning electron microscopy. The X-ray diffraction and differential scanning calorimeter data indicated that the addition of CNTs can promote the formation of β-phase of PVDF. The dielectric constant values of three PVDF/CNTs are much greater than that of neat PVDF. It has been found that the dielectric loss of the short hydroxylated CNTs filled PVDF nanocomposite is lower than those of other two long pristine CNTs filled PVDF nanocomposites.
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Stephen, Ranimol, Sabu Thomas, K. V. S. N. Raju, Siby Varghese, Kuruvilla Joseph i Zachariah Oommen. "Dynamic Mechanical and Dielectric Properties of Nanocomposites of Natural Rubber (NR), Carboxylated Styrene Butadiene Rubber (XSBR) Latices and their Blends". Rubber Chemistry and Technology 80, nr 4 (1.09.2007): 672–89. http://dx.doi.org/10.5254/1.3548187.
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Abstract The viscoelastic and dielectric properties of nano structured layered silicates reinforced natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends have been analyzed. The viscoelastic properties such as storage modulus, loss modulus, damping behavior and glass transition temperature of nano filled latices have been investigated. Upon the addition of filler, the storage modulus of nanocomposites was found to increase due to the enhancement in stiffness of the material. Due to the restricted mobility of polymer chain segments, the damping values decreased as a function of filler loading. An investigation of the viscoelastic properties revealed that there was a strong interaction between the polymer and the filler. Latex nanocomposites was characterized by X-ray diffraction technique. The enhanced d values indicated the intercalation of polymer chain into the layers of silicates. The dielectric properties of nanocomposites have been investigated as a function of frequency in the range of 50Hz–100KHz. The effect of frequency on dielectric permittivity (Ε′), dielectric loss (Ε″), dissipation factor (tan δ) and volume resistivity (ρv) of latex nanocomposite have been measured under alternating current. The dielectric permittivity of the samples was found to be higher upon the incorporation of nano fillers. The volume resistivity decreased due to the enhanced conductivity of filled samples.
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Prokhorov, Evgen, Gabriel Luna-Bárcenas, José Martín Yáñez Limón, Alejandro Gómez Sánchez i Yuriy Kovalenko. "Chitosan-ZnO Nanocomposites Assessed by Dielectric, Mechanical, and Piezoelectric Properties". Polymers 12, nr 9 (1.09.2020): 1991. http://dx.doi.org/10.3390/polym12091991.
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The aim of this work is to structurally characterize chitosan-zinc oxide nanoparticles (CS-ZnO NPs) films in a wide range of NPs concentration (0–20 wt.%). Dielectric, conductivity, mechanical, and piezoelectric properties are assessed by using thermogravimetry, FTIR, XRD, mechanical, and dielectric spectroscopy measurements. These analyses reveal that the dielectric constant, Young’s modulus, and piezoelectric constant (d33) exhibit a strong dependence on nanoparticle concentration such that maximum values of referred properties are obtained at 15 wt.% of ZnO NPs. The piezoelectric coefficient d33 in CS-ZnO nanocomposite films with 15 wt.% of NPs (d33 = 65.9 pC/N) is higher than most of polymer-ZnO nanocomposites because of the synergistic effect of piezoelectricity of NPs, elastic properties of CS, and optimum NPs concentration. A three-phase model is used to include the chitosan matrix, ZnO NPs, and interfacial layer with dielectric constant higher than that of neat chitosan and ZnO. This layer between nanoparticles and matrix is due to strong interactions between chitosan’s side groups with ZnO NPs. The understanding of nanoscale properties of CS-ZnO nanocomposites is important in the development of biocompatible sensors, actuators, nanogenerators for flexible electronics and biomedical applications.
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Tawade, Bhausaheb V., Ikeoluwa E. Apata, Nihar Pradhan, Alamgir Karim i Dharmaraj Raghavan. "Recent Advances in the Synthesis of Polymer-Grafted Low-K and High-K Nanoparticles for Dielectric and Electronic Applications". Molecules 26, nr 10 (15.05.2021): 2942. http://dx.doi.org/10.3390/molecules26102942.
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The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the “grafting from” and “grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.
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Singha, Santanu, i M. Thomas. "Dielectric properties of epoxy nanocomposites". IEEE Transactions on Dielectrics and Electrical Insulation 15, nr 1 (2008): 12–23. http://dx.doi.org/10.1109/t-dei.2008.4446732.
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Tanaka, T. "Dielectric nanocomposites with insulating properties". IEEE Transactions on Dielectrics and Electrical Insulation 12, nr 5 (październik 2005): 914–28. http://dx.doi.org/10.1109/tdei.2005.1522186.
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Wong, Shing-Chung, Erwin M. Wouterson i Eric M. Sutherland. "Dielectric properties of graphite nanocomposites". Journal of Vinyl and Additive Technology 12, nr 3 (2006): 127–30. http://dx.doi.org/10.1002/vnl.20081.
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Shimoga, Ganesh, i Sang-Youn Kim. "High-k Polymer Nanocomposite Materials for Technological Applications". Applied Sciences 10, nr 12 (20.06.2020): 4249. http://dx.doi.org/10.3390/app10124249.
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Understanding the properties of small molecules or monomers is decidedly important. The efforts of synthetic chemists and material engineers must be appreciated because of their knowledge of how utilize the properties of synthetic fragments in constructing long-chain macromolecules. Scientists active in this area of macromolecular science have shared their knowledge of catalysts, monomers and a variety of designed nanoparticles in synthetic techniques that create all sorts of nanocomposite polymer stuffs. Such materials are now an integral part of the contemporary world. Polymer nanocomposites with high dielectric constant (high-k) properties are widely applicable in the technological sectors including gate dielectrics, actuators, infrared detectors, tunable capacitors, electro optic devices, organic field-effect transistors (OFETs), and sensors. In this short colloquy, we provided an overview of a few remarkable high-k polymer nanocomposites of material science interest from recent decades.
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Zazoum, Bouchaib. "Machine Learning Approach to Predict Dielectric Permittivity of PE/TiO2 Nanocomposites". Materials Science Forum 998 (czerwiec 2020): 239–45. http://dx.doi.org/10.4028/www.scientific.net/msf.998.239.
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Controlling process parameters has significant influence in designing and developing nanocomposites materials with tailored dielectric properties. In the present study, polyethylene/TiO2 nanocomposites were fabricated using ball milling technique. The effects of TiO2 nanoparticles on the final dielectric properties of the nanocomposites in frequency domain were investigated. The dielectric spectroscopy measurements revealed that relative dielectric permittivity of the nanocompsoites was increased with TiO2 content. Besides, machine learning approach based on artificial neural networks (ANNs) algorithm was used to predict the dielectric permittivity of the nanocomposites materials. Modeling results showed clearly that the predicted data of the proposed artificial model are in good agreement with the experimental values. Moreover, the present study proved that ANNs can be used as successful tool to predict the dielectric properties of nanocomposites materials.
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Zazoum, B., E. David i A. D. Ngô. "LDPE/HDPE/Clay Nanocomposites: Effects of Compatibilizer on the Structure and Dielectric Response". Journal of Nanotechnology 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/138457.
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PE/clay nanocomposites were prepared by mixing a commercially available premixed polyethylene/O-MMT masterbatch into a polyethylene blend matrix containing 80 wt% low-density polyethylene and 20 wt% high-density polyethylene with and without anhydride modified polyethylene (PE-MA) as the compatibilizer using a corotating twin-screw extruder. In this study, the effect of nanoclay and compatibilizer on the structure and dielectric response of PE/clay nanocomposites has been investigated. The microstructure of PE/clay nanocomposites was characterized using wide-angle X-ray diffraction (WAXD) and a scanning electron microscope (SEM). Thermal properties were examined using differential scanning calorimetry (DSC). The dielectric response of neat PE was compared with that of PE/clay nanocomposite with and without the compatibilizer. The XRD and SEM results showed that the PE/O-MMT nanocomposite with the PE-MA compatibilizer was better dispersed. In the nanocomposite materials, two relaxation modes are detected in the dielectric losses. The first relaxation is due to a Maxwell-Wagner-Sillars interfacial polarization, and the second relaxation can be related to dipolar polarization. A relationship between the degree of dispersion and the relaxation ratefmaxof Maxwell-Wagner-Sillars was found and discussed.
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Balachandar, V., J. Brijitta, K. Viswanathan i R. Sampathkumar. "Investigations on the Structural, Optical and Dielectric Properties of Ball-Milled ZnO–Fe2O3 Nanocomposites". International Journal of Nanoscience 19, nr 04 (14.02.2020): 1950034. http://dx.doi.org/10.1142/s0219581x19500340.
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In this study, ZnO–Fe2O3 nanocomposites were prepared by high-energy ball milling technique and characterized through X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), UV–visible spectroscopy and dielectric spectroscopy. The amount of Fe2O3 in the ZnO–Fe2O3 nanocomposites was varied at the rates of 1[Formula: see text]wt.%, 3[Formula: see text]wt.% and 5[Formula: see text]wt.% in order to investigate its influence on the structural, optical and dielectric properties of the nanocomposites. XRD patterns of nanocomposites revealed no shift in peak positions and hence confirmed the formation of composites after ball milling. Further, it was observed from FESEM analysis that Fe2O3 particles were distributed randomly on the ZnO matrix of the nanocomposites. ZnO–Fe2O3 nanocomposites reveal extended optical absorption in the range of 400–600[Formula: see text]nm from UV studies. The dielectric constant and loss of the nanocomposites decrease exponentially with increase in frequency. The composition and frequency dependences of the dielectric constant, dielectric loss and AC conductivity are explained based on the Maxwell–Wagner effect and Koop’s theory.
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Ramazanov, M. A., A. M. Rahimli i F. V. Hajiyeva. "The influence of titanium dioxide (TiO2) nanoparticles on the structure, optical and dielectric properties of polyvinyl chloride (PVC)". Modern Physics Letters B 34, nr 28 (10.06.2020): 2050310. http://dx.doi.org/10.1142/s0217984920503108.
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The tendency to improve the properties of insulating materials by incorporating inorganic nanoparticles has become necessary in order to design new insulation systems. In this study, PVC/TiO2-based nanocomposites with different loadings (3, 5 and 10 wt.%) of TiO2 nanoparticles were prepared by the solution mixing method. The morphology of the prepared nanocomposites was studied by Atomic Force Microscope (AFM). Experimentally, it was found that as the concentration increases, the size of the surface structural elements and particle size increases. Photoluminescence (PL) analysis of samples shows improvement compared to the pristine polymer. Furthermore, PL intensity for nanocomposites increases depending on the concentration and saturation occurs at a certain amount of titanium dioxide nanoparticles. The increase in luminescence intensity till a certain nanoparticle content is due to the growth of the luminescent surface area. Further saturation is explained by the increase in particle size with no increase or a slight reduction in surface area. Dielectric properties of nanocomposites were studied. It was found that dielectric permittivity of the materials increases as the nanoparticle volume content increases and it reaches at its highest value for the nanocomposites with 3% nanoparticle content. The optical properties of the polymer and nanocomposite films were studied in the region 200 nm to 600 nm. It was found that the PVC/TiO2 nanocomposites showed enhancement in the absorbance intensities which was more significant for the nanocomposites with higher nanoparticle content compared to the pristine polymer. Furthermore, absorption spectra were used to calculate the optical bandgap of the prepared nanocomposite films and redshift observed in the calculated values of bandgap for nanocomposites. Consequently, it was proved that by incorporating TiO2 nanoparticles into the polymer matrix, the spectral region of the samples can be expanded resulting in broadened application of such systems in various fields of science and technology.
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Osipov, Mikhail A., Alexey S. Merekalov i Alexander A. Ezhov. "Molecular-Theory of High Frequency Dielectric Susceptibility of Nematic Nanocomposites". Crystals 10, nr 11 (26.10.2020): 970. http://dx.doi.org/10.3390/cryst10110970.
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A molecular-statistical theory of the high frequency dielectric susceptibility of the nematic nanocomposites has been developed and approximate analytical expressions for the susceptibility have been obtained in terms of the effective polarizability of a nanoparticle in the nematic host, volume fraction of the nanoparticles and the susceptibility of the pure nematic phase. A simple expression for the split of the plasmon resonance of the nanoparticles in the nematic host has been obtained and it has been shown that in the resonance frequency range the high frequency dielectric anisotropy of the nanocomposite may be significantly larger than that of the pure nematic host. As a result, all dielectric and optical properties of the nanocomposite related to the anisotropy are significantly enhanced which may be important for emerging applications. The components of the dielectric susceptibility have been calculated numerically for particular nematic nanocomposites with gold and silver nanoparicles as functions of the nanoparticle volume fraction and frequency. The splitting of the plasmon resonance has been observed together with the significant dependence on the nanoparticle volume fraction and the parameters of the nematic host phase.
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Thabet, Ahmed, i Youssef Mobarak. "Experimental Dielectric Measurements for Cost-fewer Polyvinyl Chloride Nanocomposites". International Journal of Electrical and Computer Engineering (IJECE) 5, nr 1 (1.02.2015): 13. http://dx.doi.org/10.11591/ijece.v5i1.pp13-22.
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<span>Polymer nanocomposites possess promising high performances as engineering materials, if they are prepared and fabricated properly. In this research, it has been processed samples of nanocomposite polymers as electrical insulating materials for application on the electric power cables by using the latest techniques of nanotechnology. This paper has been investigated enhanced dielectric and electrical properties of Polyvinyl chloride PVC as matrix have shown that trapping properties are highly modified by the presence of costless nanofillers clay and fumed silica. An experimental work for dielectric loss and capacitance of the new nanocomposite materials have been investigated and compared with unfilled industrial materials. It is found that a good correlation exists in respect of capacitance and dielectric loss values measured with percentage of nanofillers. Thus, it has been investigated the influence of costless nanofillers material and its concentration on dielectric properties of industrial polymers-based composite systems. A comparative study is performed between the unfilled base polymers, the systems containing one type of nanoparticles clay<em><span> </span></em>or fumed silica inside the host polymer with various concentrations.</span>
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Arief, Yanuar Z., Mohd Izairi Ismail, Mohamad Zul Hilmey Makmud, Aulia, Zuraimy Adzis i Nor Asiah Muhamad. "Partial Discharge Characteristics of Natural Rubber Blends with Inorganic Nanofiller as Electrical Insulating Material". Applied Mechanics and Materials 284-287 (styczeń 2013): 188–92. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.188.
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In electrical engineering, electrical discharge can occur in gaseous, liquid or solid insulating medium. Localized dielectric breakdown that occur at a small portion of a solid or fluid electrical insulation under high voltage stress is called partial discharge (PD). This phenomenon can cause the material to breakdown if there is no proper action taken. Usually it begins within voids, cracks, or inclusions within a solid dielectric, at conductor-dielectric interfaces within solid and in bubbles within liquid dielectrics. In order to modify electrical properties of the original structure then nanocomposite need to be introduced. Nanocomposite is the original structure that has been inserted by nano component (nanofiller) such as silicone dioxide and titanium dioxide. Nanocomposites are also found in nature, for example in the structure of the abalone shell and bone. By adding nano component inside the original component, it can change the mechanical and electric properties. In this study, PD characteristics of polymer-natural rubber blends nanocomposite have been investigated. The samples of nanocomposites were developed by using extrusion method. The high voltage is applied at the electrode arrangement of the test sample. The signals of partial discharges are detected by CIGRE Method II and RC detector and the signals are transferred to the personal computer using LabViewTM software. The result from the software is analyzed to find out the PD characteristics. The results revealed that the highest PD numbers are compositions with no filler while the lowest PD numbers come from sample that use 4% SiO2 as its nanofiller. The physical morphology observation is also conducted to investigate the degradation of the samples.
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Sharma, Anshu, S. P. Nehra, Y. K. Vijay i I. P. Jain. "Impact of Magnetically Aligned CNT/PC Nanocomposites for Hydrogen Gas Separation Applications". MRS Advances 1, nr 42 (2016): 2873–80. http://dx.doi.org/10.1557/adv.2016.376.
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ABSTRACTThe goal of this work is to study the properties of magnetically aligned CNT/PC nanocomposites towards the development of hydrogen gas separation membranes. A fraction (0.1 weight %) of synthesized carbon nanotubes (CNTs) have been dispersed homogeneously throughout polycarbonate (PC) matrix by ultrasonication. The alignment of CNT in PC matrix has been accomplished by applying an external magnetic field of 1200 Gauss. These nanocomposites have been studied by gas permeation using H2, N2and Co2electrical and dielectric constant measurements. Experimental results of gas permeability measurements exhibit here that H2is more selective than N2and Co2in magnetically aligned nanocomposite membranes which can be used as good hydrogen separating media. I-V characteristics show the electron hopping like behavior and dielectric constant shows the enhancement in permittivity of these nanocomposites.
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Hassan, Dalal, i Ahmed Hashim Ah-yasari. "Fabrication and studying the dielectric properties of (polystyrene-copper oxide) nanocomposites for piezoelectric application". Bulletin of Electrical Engineering and Informatics 8, nr 1 (1.03.2019): 52–57. http://dx.doi.org/10.11591/eei.v8i1.1019.
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The preparation of (polystyrene-copper oxide) nanocomposites have been investigated for piezoelectric application. The copper oxide nanoparticles were added to polystyrene by different concentrations are (0, 4, 8 and 12) wt.%. The structural and A.C electrical properties of (PS-CuO) nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of (PS-CuO) nanocomposites decrease with increase in frequency. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of polystyrene increase with increase in copper oxide nanoparticles concentrations. The results of piezoelectric application showed that the electrical resistance of (PS-CuO) nanocomposites decreases with increase in pressure.
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Ni, Xia, Ji Ma, Jiangong Li, Juanjuan Huang, Dongmao Jiao i Zhibin Lu. "Structure and Microwave Characteristics of Co/TiO2 Nanocomposites Prepared by Ball Milling". Journal of Nanoscience and Nanotechnology 8, nr 9 (1.09.2008): 4470–76. http://dx.doi.org/10.1166/jnn.2008.293.
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Co/TiO2 nanocomposites were fabricated via direct ball milling. The structure and microwave characteristics of the Co/TiO2 nanocomposites were investigated. The results show that the hcp and fcc Co phases coexist in the nanocomposites for a long milling duration. The accumulation of the stacking faults in Co and the increase of the Co/TiO2 interfaces were detected by nuclear magnetic resonance. The measured relative complex permittivity of the Co/TiO2 nanocomposite-paraffin wax mixture indicates that a high electrical resistivity and a dielectric loss exist in the Co/TiO2 nanocomposites. The dielectric loss mainly results from the polarisation of the metal/insulator interfaces. The imaginary part of the relative complex permeability of the mixture exhibits a broad resonance peak at 5.1 GHz which originates from the natural resonance in Co. The broadening of the resonance peak can be attributed to the fluctuating magnetocrystalline anisotropy at the stacking faults and interfaces regions. The calculated reflection loss curves show that the minimal reflection loss value of the Co/TiO2 nanocomposite-paraffin wax mixture can reach −32 dB at 4.0 GHz with a 3 mm sample thickness. The improved microwave absorption properties may result from the high electrical resistivity, dielectric loss and natural resonance.
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Vanin, A. I., Yu A. Kumzerov, V. G. Solov’ev, S. D. Khanin, S. E. Gango, M. S. Ivanova, M. M. Prokhorenko, S. V. Trifonov, A. V. Cvetkov i M. V. Yanikov. "Electrical and Optical Properties of Nanocomposites Fabricated by the Introduction of Iodine in Porous Dielectric Matrices". Glass Physics and Chemistry 47, nr 3 (maj 2021): 229–34. http://dx.doi.org/10.1134/s1087659621030123.
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Abstract The electrical and optical properties of nanocomposite materials fabricated by the dispersion of iodine in porous dielectric matrices of zeolites, zeolite-like aluminum phosphates, opals, asbestos, and porous aluminum oxide are studied. It is demonstrated that the physical properties of the produced nanocomposites depend significantly on the structure of a matrix.
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Lin, Jia Qi, Ying Liu, Wen Long Yang i Hui Lin. "Investigation on the Morphology and Dielectric Properties of PI/SiO2 Nanocomposite Films". Advanced Materials Research 1015 (sierpień 2014): 250–54. http://dx.doi.org/10.4028/www.scientific.net/amr.1015.250.
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Polyimide nanocomposite insulating materials are widely used in electrical and electron engineering owing to their outstanding electrical, mechanical, thermal, and wear-resistance properties. Polyimide/silica (PI/SiO2) nanocomposites have been prepared by the polymerization process of adding tetraethoxysilane (TEOS) and the coupling agent isocyanatopropyltriethoxysilane (ICTOS) in polyimide. The effects of SiO2addition on the microstructure and the dielectric property of nanocomposite films were investigated. It was found that the silica particles were well dispersed in PI matrix and the sizes of SiO2particles in the hybrid films range from 20 nm to 30 nm for 5-15 wt% SiO2loading in the matrix. The dielectric constant and the dielectric loss (tan δ) of these films increased with the increase of the content of silica particles.
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Shivashankar, H., Kevin Amith Mathias, Pavankumar R. Sondar, M. H. Shrishail i S. M. Kulkarni. "Study on low-frequency dielectric behavior of the carbon black/polymer nanocomposite". Journal of Materials Science: Materials in Electronics 32, nr 24 (31.10.2021): 28674–86. http://dx.doi.org/10.1007/s10854-021-07242-1.
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AbstractRecently, polymer-based dielectric materials have become one of the key materials to play an essential role in clean energy production, energy transformation, and energy storage applications. The end usage is the energy storage capability because it is a trade-off between dielectric permittivity, dielectric loss, and dissipation factor. Hence, it is of prime importance to study the dielectric properties of polymer materials by adding filler material at a low-frequency range. In the present study, polydimethylsiloxane/carbon black nanocomposites are prepared using the solution cast method. The dielectric properties, such as dielectric constant, dielectric loss, and dissipation factors due to the concentration of filler particles and low-frequency effect on the nanocomposites, are examined. Also, different empirical models are used to estimate the dielectric permittivity of polymer nanocomposites. The low-frequency range of 100 Hz to 1 MHz and the effect of varying volume fractions of carbon black show a significant change in the dielectric properties. It is found that the nanocomposites have a higher dielectric permittivity than the base polymer material. It is also observed that an increase in filler concentration increases the dielectric permittivity, which is confirmed with an empirical model.
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Hassan, Dalal, i Ahmed Hashim. "Synthesis of (Poly-methyl Methacrylate-lead Oxide) Nanocomposites and Studying their A.C Electrical Properties for Piezoelectric Applications". Bulletin of Electrical Engineering and Informatics 7, nr 4 (1.12.2018): 547–51. http://dx.doi.org/10.11591/eei.v7i4.969.
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Piezoelectric materials have been prepared from (poly-methyl methacrylate-lead oxide) nanocomposites for electronic applications. The lead oxide nanoparticles were added to poly-methyl methacrylate by different concentrations are (4, 8, and 12) wt%. The structural and dielectric properties of nanocomposites were studied. The results showed that the dielectric constant and dielectric loss of nanocomposites decrease with increase in frequency of applied electric field. The A.C electrical conductivity increases with increase in frequency. The dielectric constant, dielectric loss and A.C electrical conductivity of poly-methyl methacrylate increase with increase in lead oxide nanoparticles concentrations. The results of pressure sensor showed that the electrical resistance of (PMMA-PbO2) nanocomposites decreases with increase in pressure.
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Peng, Cheng, Yefeng Feng i Jianbing Hu. "Enhancing High-Frequency Dielectric Properties of Beta-SiC Filled Nanocomposites from Synergy between Percolation and Polarization". Materials 11, nr 9 (13.09.2018): 1699. http://dx.doi.org/10.3390/ma11091699.
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Promising comprehensive properties, including high permittivity, low dielectric loss, high breakdown strength, low electrical conductivity, and high thermal conductivity, are very hard to simultaneously obtain in high-frequency applicable polymer nanocomposite dielectrics. Instead of traditional electric percolation, in this work, a novel route based on a synergy between electric percolation and induced polarization has been raised to prepare 0–3 type nanocomposites with an enhanced high permittivity (high-k) property and low loss at high frequency. This work aimed at optimizing that synergy to achieve the favorable properties mentioned above in composite dielectrics used at high frequencies such as 1 MHz and 1 GHz. Conductive beta-SiC nanoparticles with a particle size of ~30 nm were employed as filler and both insulating poly(vinyl alcohol) and polyvinyl chloride were employed as polymer matrices to construct two composite systems. Utilizing polyvinyl chloride rather than poly(vinyl alcohol) realizes higher comprehensive electrical properties in composites, ascribed to optimization of that synergy. The optimization was achieved based on a combination of mild induced polarization and polarization-assisted electric percolation. Therefore, this work might open the way for large-scale production of high-frequency applicable composite dielectrics with competitive comprehensive electrical properties.
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You, Yong, Ling Tu, Yajie Wang, Lifen Tong, Renbo Wei i Xiaobo Liu. "Achieving Secondary Dispersion of Modified Nanoparticles by Hot-Stretching to Enhance Dielectric and Mechanical Properties of Polyarylene Ether Nitrile Composites". Nanomaterials 9, nr 7 (12.07.2019): 1006. http://dx.doi.org/10.3390/nano9071006.
Pełny tekst źródłaStreszczenie:
Enhanced dielectric and mechanical properties of polyarylene ether nitrile (PEN) are obtained through secondary dispersion of polyaniline functionalized barium titanate (PANI-f-BT) by hot-stretching. PANI-f-BT nanoparticles with different PANI content are successfully prepared via in-situ aniline polymerization technology. The transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic instrument (XPS) and Thermogravimetric analysis (TGA) results confirm that the PANI layers uniformly enclose on the surface of BaTiO3 nanoparticles. These nanoparticles are used as functional fillers to compound with PEN (PEN/PANI-f-BT) for studying its effect on the mechanical and dielectric performance of the obtained composites. In addition, the nanocomposites are uniaxial hot-stretched by 50% and 100% at 280 °C to obtain the oriented nanocomposite films. The results exhibit that the PANI-f-BT nanoparticles present good compatibility and dispersion in the PEN matrix, and the hot-stretching endows the second dispersion of PANI-f-BT in PEN resulting in enhanced mechanical properties, crystallinity and permittivity-temperature stability of the nanocomposites. The excellent performances of the nanocomposites indicate that a new approach for preparing high-temperature-resistant dielectric films is provided.
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Wu, Minjie, Linfeng Lu, Linhai Yu, Xiaoyan Yu, Kimiyoshi Naito, Xiongwei Qu i Qingxin Zhang. "Preparation and Characterization of Epoxy/Alumina Nanocomposites". Journal of Nanoscience and Nanotechnology 20, nr 5 (1.05.2020): 2964–70. http://dx.doi.org/10.1166/jnn.2020.17460.
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Nano-alumina (Al2O3, 30 nm) particles were employed to reinforce and toughen epoxy resin. The effects of Al2O3 nanoparticles on the mechanical properties of the composites were investigated by tensile and impact tests. It shows that the mechanical properties of epoxy nanocomposites have been improved significantly. For the prepared nanocomposite with 3.0 wt.% of Al2O3 addition, the tensile strength, elongation at break and impact strength reached 74.83 MPa, 10.63% and 13.79 kJ/m2, and were improved by 82.60%, 33.38% and 63.58%, respectively, compared with those of pure epoxy resin. The epoxy/Al2O3 nanocomposites also show good dielectric properties and excellent thermal stability under nitrogen atmosphere. Investigation of fractured surface of the obtained nanocomposites was carried out to study the dispersion of nanoarchitectonics Al2O3 with scanning electron microscopy.
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Hashim, A., i A. Hadi. "Novel Pressure Sensors Made from Nanocomposites (Biodegradable Polymers–Metal Oxide Nanoparticles): Fabrication and Characterization". Ukrainian Journal of Physics 63, nr 8 (7.09.2018): 754. http://dx.doi.org/10.15407/ujpe63.8.754.
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This paper aims to the preparation of novel pressure-sensitive nanocomposites with low cost, light weight, and good sensitivity. The nanocomposites of polyvinyl alcohol, polyacrylic acid, and lead oxide nanoparticles have been investigated. The dielectric properties and dc electrical conductivity of (PVA–PAA–PbO2) nanocomposites have been studied. The dielectric properties of nanocomposites were measured in the frequency range (100 Hz–5 MHz). The experimental results showed that the dielectric constant and dielectric loss of (PVA–PAA–PbO2) nanocomposites decrease, as the frequency increases, and they increase with the concentrations of PbO2 nanoparticles. The ac electrical conductivity of (PVA–PAA–PbO2) nanocomposites increases with the frequency and the concentrations of PbO2 nanoparticles. The dc electrical conductivity of (PVA–PAA–PbO2) nanocomposites also increases with the concentrations of PbO2 nanoparticles. The application of pressure-sensitive nanocomposites has been examined in the pressure interval (60–200) bar. The results showed that the electrical resistance of (PVA–PAA–PbO2) pressure-sensitive nanocomposites decreases, as the compressive stress increases. The (PVA–PAA–PbO2) nanocomposites have high sensitivity to pressure.