Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Dielectric polymers.
Artykuły w czasopismach na temat „Dielectric polymers”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych artykułów w czasopismach naukowych na temat „Dielectric polymers”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj artykuły w czasopismach z różnych dziedzin i twórz odpowiednie bibliografie.
1
Dou, Lvye, Yuan-Hua Lin i Ce-Wen Nan. "An Overview of Linear Dielectric Polymers and Their Nanocomposites for Energy Storage". Molecules 26, nr 20 (12.10.2021): 6148. http://dx.doi.org/10.3390/molecules26206148.
Pełny tekst źródłaStreszczenie:
As one of the most important energy storage devices, dielectric capacitors have attracted increasing attention because of their ultrahigh power density, which allows them to play a critical role in many high-power electrical systems. To date, four typical dielectric materials have been widely studied, including ferroelectrics, relaxor ferroelectrics, anti-ferroelectrics, and linear dielectrics. Among these materials, linear dielectric polymers are attractive due to their significant advantages in breakdown strength and efficiency. However, the practical application of linear dielectrics is usually severely hindered by their low energy density, which is caused by their relatively low dielectric constant. This review summarizes some typical studies on linear dielectric polymers and their nanocomposites, including linear dielectric polymer blends, ferroelectric/linear dielectric polymer blends, and linear polymer nanocomposites with various nanofillers. Moreover, through a detailed analysis of this research, we summarize several existing challenges and future perspectives in the research area of linear dielectric polymers, which may propel the development of linear dielectric polymers and realize their practical application.
2
Choi, Junhwan, i Hocheon Yoo. "Combination of Polymer Gate Dielectric and Two-Dimensional Semiconductor for Emerging Field-Effect Transistors". Polymers 15, nr 6 (10.03.2023): 1395. http://dx.doi.org/10.3390/polym15061395.
Pełny tekst źródłaStreszczenie:
Two-dimensional (2D) materials are considered attractive semiconducting layers for emerging field-effect transistors owing to their unique electronic and optoelectronic properties. Polymers have been utilized in combination with 2D semiconductors as gate dielectric layers in field-effect transistors (FETs). Despite their distinctive advantages, the applicability of polymer gate dielectric materials for 2D semiconductor FETs has rarely been discussed in a comprehensive manner. Therefore, this paper reviews recent progress relating to 2D semiconductor FETs based on a wide range of polymeric gate dielectric materials, including (1) solution-based polymer dielectrics, (2) vacuum-deposited polymer dielectrics, (3) ferroelectric polymers, and (4) ion gels. Exploiting appropriate materials and corresponding processes, polymer gate dielectrics have enhanced the performance of 2D semiconductor FETs and enabled the development of versatile device structures in energy-efficient ways. Furthermore, FET-based functional electronic devices, such as flash memory devices, photodetectors, ferroelectric memory devices, and flexible electronics, are highlighted in this review. This paper also outlines challenges and opportunities in order to help develop high-performance FETs based on 2D semiconductors and polymer gate dielectrics and realize their practical applications.
3
Liu, Di-Fan, Qi-Kun Feng, Yong-Xin Zhang, Shao-Long Zhong i Zhi-Min Dang. "Prediction of high-temperature polymer dielectrics using a Bayesian molecular design model". Journal of Applied Physics 132, nr 1 (7.07.2022): 014901. http://dx.doi.org/10.1063/5.0094746.
Pełny tekst źródłaStreszczenie:
Machine learning has shown its great potential in the accelerated discovery of advanced materials in the field of computational molecular design. High-temperature polymer dielectrics are urgently required with the emerging applications of energy-storage dielectric film capacitors under high-temperature conditions. Here, we demonstrate the successful prediction of polymers with a high dielectric constant ( ɛ) and high glass transition temperature ( Tg) using a Bayesian molecular design model. The model is trained on a joint data set containing 382 computed ɛ values using density functional perturbation theory and experimentally measured Tg values of ∼7000 polymers to build relative quantitative structure–property relationships and identify the promising polymers with specific desired range of dielectric constant and glass transition temperature. From the hypothetical polymer candidates, ten promising polymers are proposed based on their predicted properties and synthetic accessibility score for high-temperature dielectric film capacitors’ application. Moreover, 250k novel polymer structures are generated with the model to support future polymer informatics research. This work contributes to the successful prediction of high-temperature polymer dielectrics using machine learning models.
4
Yang, Zhijie, Dong Yue, Yuanhang Yao, Jialong Li, Qingguo Chi, Qingguo Chen, Daomin Min i Yu Feng. "Energy Storage Application of All-Organic Polymer Dielectrics: A Review". Polymers 14, nr 6 (14.03.2022): 1160. http://dx.doi.org/10.3390/polym14061160.
Pełny tekst źródłaStreszczenie:
With the wide application of energy storage equipment in modern electronic and electrical systems, developing polymer-based dielectric capacitors with high-power density and rapid charge and discharge capabilities has become important. However, there are significant challenges in synergistic optimization of conventional polymer-based composites, specifically in terms of their breakdown and dielectric properties. As the basis of dielectrics, all-organic polymers have become a research hotspot in recent years, showing broad development prospects in the fields of dielectric and energy storage. This paper reviews the research progress of all-organic polymer dielectrics from the perspective of material preparation methods, with emphasis on strategies that enhance both dielectric and energy storage performance. By dividing all-organic polymer dielectrics into linear polymer dielectrics and nonlinear polymer dielectrics, the paper describes the effects of three structures (blending, filling, and multilayer) on the dielectric and energy storage properties of all-organic polymer dielectrics. Based on the above research progress, the energy storage applications of all-organic dielectrics are summarized and their prospects discussed.
5
Katunin, Andrzej, i Katarzyna Krukiewicz. "Electrical percolation in composites of conducting polymers and dielectrics". Journal of Polymer Engineering 35, nr 8 (1.10.2015): 731–41. http://dx.doi.org/10.1515/polyeng-2014-0206.
Pełny tekst źródłaStreszczenie:
Abstract This article deals with the electrical conductivity of a composite of two polymers, one of which is a conducting polymer, whereas the second is a dielectric. The problem was formulated within the framework of electrical percolation, i.e., the percolation thresholds, which allow for a high electrical conductivity, is under investigation. For this purpose, a numerical model was developed, and its parameters were analyzed and discussed. Based on the determined thresholds, it was possible to evaluate the weight ratios of the conducting-dielectric polymers in a composite. The proposed approach allows for reducing the manufacturing cost of composite material with respect to conducting polymers with simultaneous retaining of high conductance properties of conducting polymers, as well as durability and flexibility of dielectrics.
6
Li, Rui, Jian Zhong Pei, Yan Wei Li, Xin Shi i Qun Le Du. "Preparation, Morphology and Dielectric Properties of Polyamide-6/Poly(Vinylidene Fluoride) Blends". Advanced Materials Research 496 (marzec 2012): 263–67. http://dx.doi.org/10.4028/www.scientific.net/amr.496.263.
Pełny tekst źródłaStreszczenie:
A novel all-polymeric material with high dielectric constant (k) has been developed by blending poly (vinylidene fluoride) (PVDF) with polyamide-6 (PA6). The dependence of the dielectric properties on frequency and polymer volume fraction was investigated. When the volume fraction of PA6 is 20%, the dielectric property is better than others. The SEM investigations suggest that the enhanced dielectric behavior originates from significant interfacial interactions of polymer-polymer. The XRD demonstrate that the PA6 and PVDF affect the crystalline behavior of each component. Furthermore, the stable dielectric constants of the blends could be tuned by adjusting the content of the polymers. The created high-k all-polymeric blends represent a novel type of material that are simple technology and easy to process, and is of relatively high dielectric constant, applications as flexible electronics.
7
Закревский, В. А., В. А. Пахотин i Н. Т. Сударь. "Долговечность полимеров в переменном электрическом поле". Журнал технической физики 90, nr 2 (2020): 251. http://dx.doi.org/10.21883/jtf.2020.02.48818.224-19.
Pełny tekst źródłaStreszczenie:
An explanation of the difference in the electrical properties of polymers in the DC and AC electric fields is proposed. Energy release during recombination of electrons and holes injected into a polymer dielectric is considered as a factor accelerating the processes of electric aging of these dielectrics in an AC field. It is shown that nonradiative relaxation of electron excited states causes breaks of bonds in macromolecules and formation of free radicals. Due to the lower ionization energy of free radicals (compared to the original molecules), the rate of charge accumulation in the polymer dielectric increases, which leads to a decrease in its durability in an AC field compared to the durability of polymers in a DC field.
8
BIJWE, JAYASHREE, i NEELAM PHOUGAT. "Dielectric Properties of Iron Phthalocyanine Compounds". Journal of Porphyrins and Phthalocyanines 02, nr 03 (maj 1998): 223–30. http://dx.doi.org/10.1002/(sici)1099-1409(199805/06)2:3<223::aid-jpp69>3.0.co;2-a.
Pełny tekst źródłaStreszczenie:
Monomeric and polymeric iron phthalocyanine compounds were synthesized and their dielectric properties were measured in the frequency range from 100 Hz to 10 MHz between 25 and 200 °C. The dielectric constant and dielectric loss showed strong frequency and temperature dependences. Interestingly, large dielectric constants were observed around 100 °C for both monomers and polymers. A dielectric constant as high as 5000 at 110 Hz was observed for the iron phthalocyanine polymer. The origin of the large dielectric constant in metallophthalocyanines is discussed.
9
Ali, Amjad, Mirza Nadeem Ahmad, Tajamal Hussain, Ahmad Naveed, Tariq Aziz, Mobashar Hassan i Li Guo. "Materials Innovations in 2D-filler Reinforced Dielectric Polymer Composites". Materials Innovations 02, nr 02 (2022): 47–66. http://dx.doi.org/10.54738/mi.2022.2202.
Pełny tekst źródłaStreszczenie:
Polymer dielectric possess advantages of mechanical flexibility, low temperature processing, and cost. However, for practical applications dielectric constant of polymers is not high enough. To raise the dielectric constant, polymers are often composited with fillers of various morphologies (one-dimensional, two-dimensional, three-dimensional) and types (inorganic, organic, carbon, conductive, non-conductive). Recently discovered two-dimensional (2D) materials including graphene, transition metal dichalcogenides, MXenes, ferroelectric ceramics, etc. have been discovered. These materials have excellent electrical, mechanical, thermal properties and high specific surface area, which makes these ideal materials to reinforce the properties of polymers, especially dielectric properties. Here, in this review we summarize the latest developments regarding the use of 2D fillers to improve the dielectric properties of polymer composites. We have systematically discussed synthesis of 2D materials, processing of their 2D filler/polymer composites, theoretical background of dielectric properties of these composites, and literature summary of the dielectric properties of polymer composites with various type of 2D fillers.
10
Li, He, Yao Zhou, Yang Liu, Li Li, Yi Liu i Qing Wang. "Dielectric polymers for high-temperature capacitive energy storage". Chemical Society Reviews 50, nr 11 (2021): 6369–400. http://dx.doi.org/10.1039/d0cs00765j.
Pełny tekst źródłaStreszczenie:
The growing demand for advanced electronics requires dielectrics operating at high temperatures. The development of high-temperature dielectric polymers is reviewed from the perspective of structure design, dielectric and capacitive performance.
11
Закревский, В. А., В. А. Пахотин i Н. Т. Сударь. "Старение и разрушение (пробой) полимерных пленок в переменном электрическом поле". Физика твердого тела 61, nr 10 (2019): 1953. http://dx.doi.org/10.21883/ftt.2019.10.48276.445.
Pełny tekst źródłaStreszczenie:
An explanation is proposed for the difference in the electrical strength properties of polymers in DC and AC fields. Energy release during recombination of electrons and holes injected into a polymer dielectric is considered as a factor accelerating the process of electrical aging of these dielectrics in AC field. It is shown that the nonradiative relaxation of electronic excited states, which causes bond breaks in macromolecules and the formation of free radicals, leads to the formation of deep electron traps in a polymer dielectric, as a result of which the ionization of macromolecules in the electric field is accelerated due to electron transitions into these traps. In solid-state plasma, a shielding effect occurs, leading to a decrease in the ionization potential of molecules. As a result, the ionization rate of macromolecules increases, i.e. the rate of formation of charge carriers, which leads to a decrease in the electrical life time of the polymer dielectric in AC field compared with the life time of polymers in DC field.
12
Chen, Xin, Qiyan Zhang, Ziyu Liu, Yifei Sun i Q. M. Zhang. "High dielectric response in dilute nanocomposites via hierarchical tailored polymer nanostructures". Applied Physics Letters 120, nr 16 (18.04.2022): 162902. http://dx.doi.org/10.1063/5.0087495.
Pełny tekst źródłaStreszczenie:
This paper presents a hierarchically designed polymer nanocomposite approach in which nanofillers at ultralow volume loading generate large dielectric enhancement in blends of high temperature dielectric polymers with tailored nanostructures. We blend poly(1,4-phenylenen ether sulfone) (PES) with polymers, such as polyetherimide (PEI), that possess more coiled chain conformations to tailor polymer nano-morphologies. Making use of such blends as the matrix, dilute nanocomposites with 0.65 vol. % loading of alumina nanoparticles (20 nm size) generate a marked enhancement in dielectric performance, i.e., raising the dielectric constant K from PES K = 3.9 (and PEI K = 3.2) to the dilute nanocomposites K = 7.6, a much higher enhancement compared with the dilute nanocomposites employing neat polymers as the matrix. The results show that polymer blends with tailored nano-morphologies as the matrix can lead to higher dielectric enhancement in dilute nanocomposites compared with neat polymers as the matrix.
13
PRATAP, A., N. J. JOSHI, P. B. RAKSHIT, G. S. GREWAL i V. SHRINET. "DIELECTRIC BEHAVIOR OF NANO BARIUM TITANATE FILLED POLYMERIC COMPOSITES". International Journal of Modern Physics: Conference Series 22 (styczeń 2013): 1–10. http://dx.doi.org/10.1142/s2010194513009859.
Pełny tekst źródłaStreszczenie:
Rapid growth of electronic industry requires development of new materials that combine the high dielectric constant intrinsic to ferroelectric ceramic materials with easy processing characteristics of polymers. Ceramic-polymeric composites possess interesting properties for a variety of electronic applications including passive electronic devices. In fact, polymer-ceramic materials have drawn lot attention for use in microelectronic packaging, because they can give higher performance with lower cost, size and weight. In this work, attempts are made to prepare ceramic polymer composites followed by characterization of dielectric properties. The Barium Titanate ceramic powders are synthesized using the hydrothermal process. Crystal structure and crystallite size of particles are determined using X-ray diffraction. Silane treatment is carried out on Barium Titanate powder to increase its compatibility with polymer, followed with preparation of ceramic polymer composites. Epoxy and polyvinyledene fluoride (PVDF) polymers are used as matrices for preparation of the composites. The proportion of nanopowder is varied from 60 to 90 wt%. Dielectric properties such as volume resistivity, dielectric constant, dissipation factor are evaluated. Results indicate that the dielectric constant and dissipation factor vary between 18 -140 and 0.01 to 0.09, respectively as the relative ratio of polymer and silane modified Barium Titanate is varied. Specifically, at 90 wt% of 0.1 wt% silane modified Barium Titanate, the highest dielectric constant of 140 along with dissipation factor of 0.07 is obtained in the epoxy based system.
14
Lu, T.-M., i J. A. Moore. "Vapor Deposition of Low-Dielectric-Constant Polymeric Thin Films". MRS Bulletin 22, nr 10 (październik 1997): 28–31. http://dx.doi.org/10.1557/s0883769400034163.
Pełny tekst źródłaStreszczenie:
For devices with feature sizes below 0.18 μm, it is desirable to have materials with a dielectric constant below 2.5 as interlayer dielectrics. Polymeric materials are possible candidates. There are two main strategies to grow polymeric films. The most widely used method is the spin-on technique. The other method is by vapor deposition. Although vapor deposition is less common, it has several attractive features that look quite promising, especially when the wafer size becomes very large.There are several advantages to vapor-deposited polymers:(1) The deposition of the polymers is a dry process. It is solvent-free and does not produce waste. No remedial measures are necessary to take care of the waste. The process is attractive from both energy-conservation and environmental considerations.(2) They can provide an extremely uniform coating over a very large area. For 200-mm wafers, for example, one can achieve better than 2% uniformity for vapor-deposited parylene (a type of polymer to be described later) films. Similar uniformity can be expected for future 300-mm wafers.(3) Many vapor-deposited polymers possess superior gap-filling capability. Small vias and trenches of very high aspect ratios can be filled without voids.There are some shortcomings in vapor deposition of polymeric thin films. First of all, except for some special cases, processing issues for these materials are not well-studied. Manufacturing equipment is not well-developed.
15
Ahmed, Hameed M., i Shuja-Aldeen B. Aziz. "Dielectric Properties of Commercial non-Polar Polymers". Journal of Zankoy Sulaimani - Part A 11, nr 1 (10.04.2008): 1–8. http://dx.doi.org/10.17656/jzs.10175.
Pełny tekst źródła
16
Susarla, Sandhya, Thierry Tsafack, Peter Samora Owuor, Anand B. Puthirath, Jordan A. Hachtel, Ganguli Babu, Amey Apte i in. "High-K dielectric sulfur-selenium alloys". Science Advances 5, nr 5 (maj 2019): eaau9785. http://dx.doi.org/10.1126/sciadv.aau9785.
Pełny tekst źródłaStreszczenie:
Upcoming advancements in flexible technology require mechanically compliant dielectric materials. Current dielectrics have either high dielectric constant, K (e.g., metal oxides) or good flexibility (e.g., polymers). Here, we achieve a golden mean of these properties and obtain a lightweight, viscoelastic, high-K dielectric material by combining two nonpolar, brittle constituents, namely, sulfur (S) and selenium (Se). This S-Se alloy retains polymer-like mechanical flexibility along with a dielectric strength (40 kV/mm) and a high dielectric constant (K = 74 at 1 MHz) similar to those of established metal oxides. Our theoretical model suggests that the principal reason is the strong dipole moment generated due to the unique structural orientation between S and Se atoms. The S-Se alloys can bridge the chasm between mechanically soft and high-K dielectric materials toward several flexible device applications.
17
Albeltagi, Ahmed, Katherine Gallegos-Rosas i Caterina Soldano. "High-k Fluoropolymers Dielectrics for Low-Bias Ambipolar Organic Light Emitting Transistors (OLETs)". Materials 14, nr 24 (11.12.2021): 7635. http://dx.doi.org/10.3390/ma14247635.
Pełny tekst źródłaStreszczenie:
Organic light emitting transistors (OLETs) combine, in the same device, the function of an electrical switch with the capability of generating light under appropriate bias conditions. In this work, we demonstrate how engineering the dielectric layer based on high-k polyvinylidene fluoride (PVDF)-based polymers can lead to a drastic reduction of device driving voltages and the improvement of its optoelectronic properties. We first investigated the morphology and the dielectric response of these polymer dielectrics in terms of polymer (P(VDF-TrFE) and P(VDF-TrFE-CFE)) and solvent content (cyclopentanone, methylethylketone). Implementing these high-k PVDF-based dielectrics enabled low-bias ambipolar organic light emitting transistors, with reduced threshold voltages (<20 V) and enhanced light output (compared to conventional polymer reference), along with an overall improvement of the device efficiency. Further, we preliminary transferred these fluorinated high-k dielectric films onto a plastic substrate to enable flexible light emitting transistors. These findings hold potential for broader exploitation of the OLET platform, where the device can now be driven by commercially available electronics, thus enabling flexible low-bias organic electronic devices.
18
Bonardd, Sebastián, Viviana Moreno-Serna, Galder Kortaberria, David Díaz Díaz, Angel Leiva i César Saldías. "Dipolar Glass Polymers Containing Polarizable Groups as Dielectric Materials for Energy Storage Applications. A Minireview". Polymers 11, nr 2 (13.02.2019): 317. http://dx.doi.org/10.3390/polym11020317.
Pełny tekst źródłaStreszczenie:
Materials that have high dielectric constants, high energy densities and minimum dielectric losses are highly desirable for use in capacitor devices. In this sense, polymers and polymer blends have several advantages over inorganic and composite materials, such as their flexibilities, high breakdown strengths, and low dielectric losses. Moreover, the dielectric performance of a polymer depends strongly on its electronic, atomic, dipolar, ionic, and interfacial polarizations. For these reasons, chemical modification and the introduction of specific functional groups (e.g., F, CN and R−S(=O)2−R´) would improve the dielectric properties, e.g., by varying the dipolar polarization. These functional groups have been demonstrated to have large dipole moments. In this way, a high orientational polarization in the polymer can be achieved. However, the decrease in the polarization due to dielectric dissipation and the frequency dependency of the polarization are challenging tasks to date. Polymers with high glass transition temperatures (Tg) that contain permanent dipoles can help to reduce dielectric losses due to conduction phenomena related to ionic mechanisms. Additionally, sub-Tg transitions (e.g., γ and β relaxations) attributed to the free rotational motions of the dipolar entities would increase the polarization of the material, resulting in polymers with high dielectric constants and, hopefully, dielectric losses that are as low as possible. Thus, polymer materials with high glass transition temperatures and considerable contributions from the dipolar polarization mechanisms of sub-Tg transitions are known as “dipolar glass polymers”. Considering this, the main aspects of this combined strategy and the future prospects of these types of material were discussed.
19
Zhang, Xuan, Ziqi Wen, Hongxing Zhang, Weihua Han, Jinyi Ma, Renbo Wei i Xiufu Hua. "Dielectric Properties of Azo Polymers: Effect of the Push-Pull Azo Chromophores". International Journal of Polymer Science 2018 (2018): 1–10. http://dx.doi.org/10.1155/2018/4541937.
Pełny tekst źródłaStreszczenie:
The relationship between the structure and the dielectric properties of the azo polymers was studied. Four azo polymers were synthesized through the azo-coupling reaction between the same precursor (PAZ) and diazonium salts of 4-aminobenzoic acid ethyl ester, 4-aminobenzonitrile, 4-nitroaniline, and 2-amino-5-nitrothiazole, respectively. The precursor and azo polymers were characterized by 1H NMR, FT-IR, UV-vis, GPC, and DSC. The dielectric constant and dielectric loss of the samples were measured in the frequency range of 100 Hz–200 kHz. Due to the existence of the azo chromophores, the dielectric constant of the azo polymers increases compared with that of the precursor. In addition, the dielectric constant of the azo polymers increases with the increase of the polarity of the azo chromophores. A random copolymer (PAZ-NT-PAZ) composed of the azo polymer PAZ-NT and the precursor PAZ was also prepared to investigate the content of the azo chromophores on the dielectric properties of the azo polymers. It showed that the dielectric constant increases with the increase of the azo chromophores. The results show that the dielectric constant of this kind of azo polymers can be controlled by changing the structures and contents of azo chromophores during the preparation process.
20
Wang, Chao, Guanghu He, Sheng Chen, Di Zhai, Hang Luo i Dou Zhang. "Enhanced performance of all-organic sandwich structured dielectrics with linear dielectric and ferroelectric polymers". Journal of Materials Chemistry A 9, nr 13 (2021): 8674–84. http://dx.doi.org/10.1039/d1ta00974e.
Pełny tekst źródłaStreszczenie:
We develop advanced polymer capacitors for flexible electrostatic high temperature energy storage applications via designing all-organic sandwich structured films consisting of ferroelectric and linear dielectric polymers.
21
Ganesh, S. D., M. N. K. Harish, B. J. Madhu, Husnasarvari Maqbool, K. V. Pai i M. Y. Kariduraganavar. "Poly(Arylene Ether Sulfone)s with HEPES Pendants: Synthesis, Thermal, and Dielectric Studies". ISRN Polymer Science 2013 (29.05.2013): 1–7. http://dx.doi.org/10.1155/2013/897034.
Pełny tekst źródłaStreszczenie:
Polyethersulfone with active carboxylic acid pendants was prepared from solution polymerization via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS) and 4,4′-bis(4-hydroxyphenyl) valeric acid (BHPA). The conditions necessary to synthesize and purify the polymer were investigated in some details. The synthesized polyethersulfone comprises sulfone and ether linkages in addition to reactive carboxylic acid functionality; this reactive carboxylic acid group was exploited to hold the HEPES moiety via ester linkage and is achieved by simple DCC coupling condition at ambient temperature. Without impairing the primary polymeric backbone, three modified polymers were prepared by varying the stoichiometric ratio of HEPES. Characterization of the polymers by 1H & 13C NMR, FT-IR, and TGA demonstrated that HEPES was quantitatively incorporated into the prime polymer. All the prepared polymers were pressed into tablets, and electrical contacts were established to study the dielectric properties. Finally, the influence of the HEPES on the dielectric properties was examined.
22
Butorin, Denis. "Automated control system to monitor dielectric losses in polymers". MATEC Web of Conferences 216 (2018): 02003. http://dx.doi.org/10.1051/matecconf/201821602003.
Pełny tekst źródłaStreszczenie:
The basic property of the processed polymers when it comes to high-frequency heat treatment is their dielectric losses. The purpose of the present study is elaboration of automated control system to monitor dielectric losses in polymers during heating. The technique developed in the given paper implies linear uniform heating of the studied material by contact method with the given velocity and when heating is off, periodic short-term action of high-frequency electric field on the polymer after each temperature growth of polymer per preset degree. The studies conducted in the automatic mode allowed obtaining new knowledge on changing electro-physical properties of polymers during heat treatment; and determining the new parameter to control polymer state while high-frequency processing; distinguishing and identifying different relaxation transitions of polymer materials during heating and thus broadening applicability of high-frequency heat treatment.
23
Hacker, Nigel P. "Organic and Inorganic Spin-On Polymers for Low-Dielectric-Constant Applications". MRS Bulletin 22, nr 10 (październik 1997): 33–38. http://dx.doi.org/10.1557/s0883769400034175.
Pełny tekst źródłaStreszczenie:
Low-dielectric-constant materials (k < 3.0) have the advantage of facilitating manufacture of higher performance integrated-circuit (IC) devices with minimal increases in chip size. The reduced capacitance given by these materials permits shrinkage of spacing between metal lines to below 0.25 μm and the ability to decrease the number of levels of metal in a device. The technologies being considered for low-k applications are chemical vapor deposition (CVD) or spin-on of polymeric materials. For both types of processes, there are methods and materials capable of giving k < 3.0 dielectric stacks. This article will focus on the spin-on approach and discuss the properties of both organic and inorganic spin-on polymers.While CVD SiO2 has been the mainstay of the industry, spin-on materials are appropriate for many dielectric applications. Polyimides have applications as electrical insulators, and traditional spin-on silicates or siloxanes (k > 3.0) have served as planarizing dielectrics during the last 15 years. The newer spin-on polymers have greatly enhanced mechanical, thermal, and chemical properties, exhibiting lower dielectric constants than the traditional materials.
24
Endo, Kazuhiko. "Fluorinated Amorphous Carbon as a Low-Dielectric-Constant Interlayer Dielectric". MRS Bulletin 22, nr 10 (październik 1997): 55–58. http://dx.doi.org/10.1557/s0883769400034217.
Pełny tekst źródłaStreszczenie:
Low-k organic polymers such as polytetrafluoroethylene (PTFE) are promising materials for use as interlayer dielectrics (ILD) because their dielectric constants are generally lower than those of inorganic materials. However poor adhesion with Si substrates, poor thermal stability, and production difficulties have hindered their use in microelectronics.On the other hand, plasma-enhanced chemical vapor deposition (PECVD) of polymer films (plasma polymerization) has many advantages that help to overcome these problems. Plasma-enhanced chemical vapor deposition uses a glow discharge to create activated species such as radicals and ions from the original monomer, and the polymer films are deposited through various gas-phase and surface reactions of these active species, including ablation of the deposited film. No water is generated during plasma polymerization, and the influence of a solvent can be ignored. Also a layered structure that promotes adhesion can be easily fabricated by changing the source compounds.Recently the use of fluorinated amorphous carbon thin films (a-C:F) as new low-dielectric-constant interlayer dielectrics has been proposed. These thin films have an amorphous C–C cross-linked structure (including sp3 and sp2 bonded carbon) and have the same C–F bonds found in PTFE. The strong C–F bonds decrease the dielectric constant, and the C–C crosslinked structure maintains the film's thermal stability. The a-C:F film can be deposited from fluorocarbon source materials using PECVD. Typically fluorocarbons such as CF4, C2F6, C4F8, and their hydrogen mixtures are used as source materials. First the a-C:F films for low-k ILD, with a dielectric constant of 2.1, were deposited from CH4 + CF4 mixtures by using parallel-plate PECVD.
25
Gubanov, O. M., D. S. Alymov i V. N. Gadalov. "Effects of electrical discharges and deformation on the electrophysical and mechanical properties of high-pressure polyethylene". Glavnyj mekhanik (Chief Mechanic), nr 12 (16.11.2021): 50–57. http://dx.doi.org/10.33920/pro-2-2112-04.
Pełny tekst źródłaStreszczenie:
Studies of the mechanical electrophysical properties of polymers and their modifications under the simultaneous influence of electrical discharges and mechanical force are presented. It is shown that a decrease in the electrophysical characteristics of the studied polymer materials in the presence of a tensile mechanical force leads to the accumulation of bulk charges in them and the formation of submicrocracks. This is indicated by the established relationship between the processes of formation and development of submicrocracks with the accumulation of bulk charge in polymers. These processes in their physical essence are elementary acts of destruction of polymer dielectrics, the development of which is determined by experimental conditions. It was found that when methylphenyltolylamine is introduced into the composition of high-pressure polyethylene, the structure of the resulting polymer modifications changes markedly. Therefore, a change in their dielectric losses and specific volume electrical resistivity should be expected. Indeed, as follows from the experimental data, the introduction of the proposed additive into high-pressure polyethylene in an optimal amount contributes to an increase in their volume resistivity by an order of magnitude and a decrease in dielectric losses. The authors have made an assumption that the detected decrease in the electrical strength of the films of the original and modified high-pressure polyethylene under the simultaneous influence of mechanical load on them is explained by the accelerated accumulation of bulk charges and the growth of microcracks, as a result of which ionization processes are intensively taking place in the developing inhomogeneities of the polymer dielectric. As follows from the results obtained, as the degree of mechanically stressed state of the samples increases, their durability decreases. This indicates that, along with a high electric field, one of the reasons for the appearance of bulk charges and inhomogeneities in the form of microcracks in polymer dielectrics is their mechanically stressed state.
26
Albarrán Preza, Esthela, Enrique Vigueras-Santiago i Susana Hernández López. "Synthesis and Characterization of Azobenzene-Containing Polydiacetylene Polymers". Advanced Materials Research 976 (czerwiec 2014): 46–51. http://dx.doi.org/10.4028/www.scientific.net/amr.976.46.
Pełny tekst źródłaStreszczenie:
Polydiacetylenes are a type of highly conjugated polymers, and highly polar species are obtained when these polymers contain donor-acceptor azobenzene entities. In this paper the synthesis, characterization and evaluation of the dielectric constant of two polydiacetylenes containing azobenzenes as pendant groups are discussed. The Azobenzene chromophores are covalently bonded to the main chain, and their polarity is defined by an electro-donor (amine) and an electro-acceptor group (nitro or chlorine) bonded to the ends of a conjugated azobenzene structure. Both polymers were processed into plates of 1cm diameter x 0.674 mm thickness using a thermo mechanic technique. Their dielectric constants were evaluated respect to the temperature in a range of frequency of 110 MHz-1.32 GHz, from room temperature to close to their respective Tg. The dielectric constant for the polymer containing the nitro group was higher than it for polymer containing the chloride atom at all temperatures. It is discussed in terms of the ability to nitro and chloride to attract electronic density.
27
Kulkarni, Anandrao S., M. V. N. Ambika Prasad, Hajeebaba K. Inamdar i Vijendra A. Chaudhari. "Studies on AC Conductivity and Dielectric Properties of Conducting Polyaniline-AgO Nanocomposites". Advanced Materials Research 1169 (18.03.2022): 21–25. http://dx.doi.org/10.4028/p-63kf34.
Pełny tekst źródłaStreszczenie:
Polymers with metal oxide materials constitute a new class of polymer composite materials, that integrates materials science and technology. Chemical oxidation of aniline is carried out for PANI (PANI) and in-situ polymerization for PANI/AgO nanocomposite materials. Characterization tools such as XRD and SEM were used. The AC conductivity and dielectric behavior are investigated in the frequency range 100 to 2MHz at room temperature. It is observed that, the AgO nanoparticles in the PANI matrix have a greater influence on the AC conductivity and dielectrics.
28
Shi, W., C. Fang, S. Guo, Q. Ren, Q. Pan, Q. Gu, D. Xu, H. Wei i J. Yu. "Investigation on dielectric properties of the polyetherketone nanocomposite with lead titanate ultrafines". Canadian Journal of Physics 79, nr 5 (1.05.2001): 847–55. http://dx.doi.org/10.1139/p01-040.
Pełny tekst źródłaStreszczenie:
The dielectric properties of polymer composites with inorganic nanoparticles were investigated. In the demonstration of the dielectric constant expression of the nanocomposite polymer, the dielectric contributions of the displacement polarization, the orientation polarization, and the space polarization in the nanocomposite polymer were all considered. In the demonstration, two dielectric relaxation models were used, that of Debye for inorganic nanoparticles and the HavriliakNegami function model for polymers. Then the expression of the complex dielectric constant of the nanocomposite polymer was obtained by using Onsager's local field theory. Furthermore, the nanocomposite polymer thin films that consist of PbTiO3 nanoparticles and polyetherketone were prepared. The real parts of the dielectric constants were measured and calculated, respectively. It was found that our calculated results are in good agreement with our measured results. PACS Nos.: 77.20, 77.55, 81.20T
29
Shi, Yuhao, Yingkai Zheng, Jialiang Wang, Ran Zhao, Tao Wang, Changbin Zhao, Kuan-Chang Chang, Hong Meng i Xinwei Wang. "Hysteresis-Free, High-Performance Polymer-Dielectric Organic Field-Effect Transistors Enabled by Supercritical Fluid". Research 2020 (30.08.2020): 1–10. http://dx.doi.org/10.34133/2020/6587102.
Pełny tekst źródłaStreszczenie:
Organic field-effect transistors (OFETs) are of the core units in organic electronic circuits, and the performance of OFETs replies critically on the properties of their dielectric layers. Owing to the intrinsic flexibility and natural compatibility with other organic components, organic polymers, such as poly(vinyl alcohol) (PVA), have emerged as highly interesting dielectric materials for OFETs. However, unsatisfactory issues, such as hysteresis, high subthreshold swing, and low effective carrier mobility, still considerably limit the practical applications of the polymer-dielectric OFETs for high-speed, low-voltage flexible organic circuits. This work develops a new approach of using supercritical CO2 fluid (SCCO2) treatment on PVA dielectrics to achieve remarkably high-performance polymer-dielectric OFETs. The SCCO2 treatment is able to completely eliminate the hysteresis in the transfer characteristics of OFETs, and it can also significantly reduce the device subthreshold slope to 0.25 V/dec and enhance the saturation regime carrier mobility to 30.2 cm2 V−1 s−1, of which both the numbers are remarkable for flexible polymer-dielectric OFETs. It is further demonstrated that, coupling with an organic light-emitting diode (OLED), the SCCO2-treated OFET is able to function very well under fast switching speed, which indicates that an excellent switching behavior of polymer-dielectric OFETs can be enabled by this SCCO2 approach. Considering the broad and essential applications of OFETs, we envision that this SCCO2 technology will have a very broad spectrum of applications for organic electronics, especially for high refresh rate and low-voltage flexible display devices.
30
Burke, Andrew. "Prospects for the Development of High Energy Density Dielectric Capacitors". Applied Sciences 11, nr 17 (31.08.2021): 8063. http://dx.doi.org/10.3390/app11178063.
Pełny tekst źródłaStreszczenie:
In this paper, the design of high energy density dielectric capacitors for energy storage in vehicle, industrial, and electric utility applications have been considered in detail. The performance of these devices depends primarily on the dielectric constant and breakdown strength characteristics of the dielectric material used. A review of the literature on composite polymer materials to assess their present dielectric constants and the various approaches being pursued to increase energy density found that there are many papers in which materials having dielectric constants of 20–50 were reported, but only a few showing materials with very high dielectric constants of 500 and greater. The very high dielectric constants were usually achieved with nanoscale metallic or carbon particles embedded in a host polymer and the maximum dielectric constant occurred near the percolation threshold particle loading. In this study, an analytical method to calculate the dielectric constant of composite dielectric polymers with various types of nanoparticles embedded is presented. The method was applied using an Excel spreadsheet to calculate the characteristics of spiral wound battery cells using various composite polymers with embedded particles. The calculated energy densities were strong functions of the size of the particles and thickness of the dielectric layer in the cell. For a 1000 V cell, an energy density of 100–200 Wh/kg was calculated for 3–5 nm particles and 3–5 µ thick dielectric layers. The results of this study indicate that dielectric materials with an effective dielectric constant of 500–1000 are needed to develop dielectric capacitor cells with battery-like energy density. The breakdown strength would be 300–400 V/µ in a reverse sandwich multilayer dielectric arrangement. The leakage current of the cell would be determined from appropriate DC testing. These high energy density dielectric capacitors are very different from electrochemical capacitors that utilize conducting polymers and liquid electrolytes and are constructed much like batteries. The dielectric capacitors have a very high cell voltage and are constructed like conventional ceramic capacitors.
31
Abdullah, Ahmed Q. "Effect of UV radiation on dielectric properties of PU/nano-TiO2 composites". Iraqi Journal of Physics (IJP) 15, nr 33 (8.01.2019): 49–53. http://dx.doi.org/10.30723/ijp.v15i33.139.
Pełny tekst źródłaStreszczenie:
The dielectric constant of most polymers is very low; the addition of TiO2 particles into the polymers provides an attractive and promising way to reach a high dielectric constant. Polymer-based materials with a high dielectric constant show great potential for energy storage applications. Four samples were prepared, one of them was polyurethane (PU) and the other were PU with different weight percent (wt %) of TiO2 (0.1, 0.2, 0.3) powder AFM test was used to distinguish the nanoparticles. The result shows that the most shape of these nanoparticles are spherical and the roughness average is 0.798 nm. The dielectric properties were measured for all samples before and after the exposure to the UV radiation. The result illustrates that the dielectric constant decreased and the dielectric loss increased, the amount of decrease in the dielectric constant decreases with the increasing of the TiO2 concentration that added to the PU and decreasing in the amount of dielectric loss.
32
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.
Pełny tekst źródłaStreszczenie:
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.
33
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.
Pełny tekst źródłaStreszczenie:
<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>
34
Li, Zongze, Gregory M. Treich, Mattewos Tefferi, Chao Wu, Shamima Nasreen, Sydney K. Scheirey, Rampi Ramprasad, Gregory A. Sotzing i Yang Cao. "High energy density and high efficiency all-organic polymers with enhanced dipolar polarization". Journal of Materials Chemistry A 7, nr 25 (2019): 15026–30. http://dx.doi.org/10.1039/c9ta03601f.
Pełny tekst źródła
35
Feng, Yudi, Ke Jin, Jia Guo i Changchun Wang. "All-carbocycle hydrocarbon thermosets with high thermal stability and robust mechanical strength for low-k interlayer dielectrics". Polymer Chemistry 12, nr 33 (2021): 4812–21. http://dx.doi.org/10.1039/d1py00877c.
Pełny tekst źródłaStreszczenie:
Two kinds of hydrocarbon precursors were synthesized and cured at elevated temperatures to give cross-linked all-aliphatic/aromatic-ring polymers with a low dielectric constant for next-generation interlayer dielectrics.
36
HERBEI, Elena Emanuela. "Dielectric PMMA Thin Layers Obtained by Spin Coating for Electronic Applications". Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science 45, nr 4 (15.12.2022): 87–91. http://dx.doi.org/10.35219/mms.2022.4.14.
Pełny tekst źródłaStreszczenie:
Thin polymeric films with dielectric properties become a very important part of today’s devices, being indispensable in industry, electrical applications and not only. Nowadays polymeric materials have attracted attention in academic and industrial research due to the miniaturization at the micro and nanoscale of different electronic devices. Polymers in general are used for their light weight, good mechanical strength, dielectric properties, and optical properties, which make them multifunctional materials.This paper presents research on polymethyl methacrylate (PMMA) thin films obtained by the sol-gel method. The optimization of thin film PMMA layers has been a problem due to the importance of using the polymer in the different electronic domains. Thin films of PMMA with different thicknesses were deposited onto glass and silicon wafers in order to measure dielectric properties. For dielectric properties, the PMMA thin layer was inserted in a metal-insulator-metal structure (MIM). In order to observe the morphology and roughness of thin film, optical microscopy, scanning electron microscopy and atomic force microscopy have proceeded.The dielectric constant (k) was calculated using the electrical capacitance formula. The I-V and C-V curves showed a dielectric behavior with a leakage current between 10-11 and 10-8 A and a constant capacitance in the bias range ± 5 V.
37
TUHVATULLIN, Midhat, Yuri ARKHANGELSKY, Rustam AIPOV i Eduard KHASANOV. "Innovations in designing microwave electro-technological units with hybrid chambers". Spanish Journal of Agricultural Research 21, nr 1 (23.02.2023): e0202. http://dx.doi.org/10.5424/sjar/2023211-19683.
Pełny tekst źródłaStreszczenie:
Aim of study: Microwave (MW) electro-technological units based on electromagnetic radiation of ultrahigh-frequency can involve thermal MW modification of dielectrics and non-thermal MW modification of polymers.
Area of study: Russian Federation.
Material and methods: The paper considers a method for making a unit with a hybrid chamber, where thermal and non-thermal MW modifications were carried out simultaneously, and the remaining energy after non-thermal MW modification of polymers was used for heating the dielectric.
Main results: A microwave electro-technological unit with a hybrid chamber replaced two separate devices that implemented these MW modifications. It was cheaper and required one MW generator. The unit took up less space than two separate apparatuses, and upgraded the existing microwave dryer to perform thermal MW modification of a lumber pile and non-thermal MW modification of polymer materials. The existing microwave dryer was redeveloped by solving the boundary value problem in electrodynamics and heat and mass transfer.
Research highlights: The research presents a microwave electro-technological unit with a hybrid chamber, combining thermal and non-thermal MW modifications of dielectric and polymer materials. As a result of upgrading the existing microwave dryer, it was possible to carry out both thermal and non-thermal MW modifications, namely, microwave drying of timber and microwave drying of up to seven different polymer objects.
38
Deeba, Farah, Kriti Shrivastava, Minal Bafna i Ankur Jain. "Tuning of Dielectric Properties of Polymers by Composite Formation: The Effect of Inorganic Fillers Addition". Journal of Composites Science 6, nr 12 (22.11.2022): 355. http://dx.doi.org/10.3390/jcs6120355.
Pełny tekst źródłaStreszczenie:
Polymer blend or composite, which is a combination of two or more polymers and fillers such as semiconductors, metals, metal oxides, salts and ceramics, are a synthesized product facilitating improved, augmented or customized properties, and have widespread applications for the achievement of functional materials. Polymer materials with embedded inorganic fillers are significantly appealing for challenging and outstanding electric, dielectric, optical and mechanical applications involving magnetic features. In particular, a polymer matrix exhibiting large values of dielectric constant (ε′) with suitable thermal stability and low dielectric constant values of polymer blend, having lesser thermal stability, together offer significant advantages in electronic packaging and other such applications in different fields. In this review paper, we focused on the key factors affecting the dielectric properties and its strength in thin film of inorganic materials loaded poly methyl meth acrylate (PMMA) based polymer blend (single phase) or composites (multiple phase), and its consequences at low and high frequencies are explored. A wide range of different types of PMMA based polymer blends or composites, which are doped with different fillers, have been synthesized with specific tailoring of their dielectric behavior and properties. A few of them are discussed in this manuscript, with their different preparation techniques, and exploring new ideas for modified materials.
39
Адамьян, Ю. Э., С. И. Кривошеев i С. Г. Магазинов. "Особенности описания импульсной электрической прочности полимерных диэлектриков". Письма в журнал технической физики 47, nr 5 (2021): 48. http://dx.doi.org/10.21883/pjtf.2021.05.50679.18621.
Pełny tekst źródłaStreszczenie:
The scenario based on the macro molecules field ionization model is proposed to describe the polymer dielectrics pulse breakdown. The decisive role of the real dielectric space-field inhomogeneity on formation of the ionization “sources” and redistribution of charge carries is taken into account. The justification of the choice of the defining model parameters - energy gap width and frequency factor is carried out. The possibility of using these parameters to describe the pulse electric strength of polymers in both uniform and sharply non-uniform electric fields (on the example of polymethylmethaacrylate) is shown.
40
Dang, Zhi-Min, Jin-Kai Yuan, Jun-Wei Zha, Peng-Hao Hu, Dong-Rui Wang i Zhong-Yang Cheng. "High-permittivity polymer nanocomposites: Influence of interface on dielectric properties". Journal of Advanced Dielectrics 03, nr 03 (lipiec 2013): 1330004. http://dx.doi.org/10.1142/s2010135x13300041.
Pełny tekst źródłaStreszczenie:
Flexible dielectric composites with high permittivity have been extensively studied due to their potential applications in high-density energy capacitors. In this review, effects of interface characteristics on the dielectric properties in the polymer-based nanocomposites with high permittivity are analyzed. The polymer-based dielectric composites are classified into two types: dielectric–dielectric (DD, ceramic particle-polymer) composites and conductor–dielectric (CD, conductive particle-polymer) composites. It is highly desirable for the dielectric–dielectric composites to exhibit high permittivity at low content of ceramic particles, which requires a remarkable interface interaction existing in the composite. For conductor–dielectric composites, a high permittivity can be achieved in composite with a small amount of conductor particle, but associated with a high loss. In this case, the interface between conductor and polymer with a good insulating characteristic is very important. Different methods can be used to modify the surface of ceramic/conductor particles before these particles are dispersed into polymers. The experimental results are summarized on how to design and make the desirable interface, and recent achievements in the development of these nanocomposites are presented. The challenges facing the fundamental understanding on the role of interface in high-permittivity polymer nanocomposites should be paid a more attention.
41
Leong, D. B., M. A. Helfand, R. L. McConville i F. W. Mercer. "The structure and chemistry of polymer metal interfaces: A combined EM and XPS investigation". Proceedings, annual meeting, Electron Microscopy Society of America 50, nr 1 (sierpień 1992): 196–97. http://dx.doi.org/10.1017/s0424820100121387.
Pełny tekst źródłaStreszczenie:
Polymer to metal relationships for applications from coating finishes to electronic devices require interfacial synergy. Polymer application requirements range in temperature, thermal stability, thermal expansion, moisture absorption, oxidative stability, etc. and choice of metal and deposition technique must take into account these characteristics. While the ability to deposit metal in a controllable fashion is well established the present study focuses on what takes place at the polymer metal interface. Polymer/metal interactions on polyimide systems have been studied in detail for the past decade by a variety of analytical techniques. For the first time this is being investigated in the FPAE polymers combining EM study for structural analysis and XPS for chemical analysis. Fluorinated poly (arly ethers) FPAE, are a newly developed class of polymeric dielectric materials for electronic packaging. These new materials exhibit excellent oxidative stability, low moisture absorption and low dielectric constant. While these parameters are critical for electronic device performance and longevity, device performance is also highly dependent on metallization of the polymer.
42
Trajkovska, Anka. "Inorganic dopants in polymer cholesteric liquid crystals". Macedonian Journal of Chemistry and Chemical Engineering 34, nr 2 (12.11.2015): 381. http://dx.doi.org/10.20450/mjcce.2015.629.
Pełny tekst źródłaStreszczenie:
<p>A variety of dopants are used for different types of polymers to change their properties. Inorganic dopants are usually used to change the dielectric properties of the polymers. These compositions find different applications especially in electronic systems due to ease of polymer processing, increased functionality and low cost of novel materials that are with relatively high dielectric constant compared to the base polymer material.</p><p>In this study, polymer cholesteric liquid crystal (PCLC) is used as a host material that is doped by different inorganic dopants, BaTiO<sub>3</sub> and TiO<sub>2</sub>, all of them affected the dielectric constant of the polymer matrix. This is important from the fact that doped PCLC can be used for a variety of electro-optical applications, e.g. display applications and low energy consuming e-book application. The behaviour of inorganic dopants in PCLC is calculated by various existing mixing models; the best fit is observed by use of logarithmic equation.</p>
43
Abdullah, Nadhim A., i Fatima H. Malk. "Optical Properties of Blend of PMMA:PVDF". University of Aden Journal of Natural and Applied Sciences 25, nr 1 (22.03.2022): 189–96. http://dx.doi.org/10.47372/uajnas.2021.n1.a16.
Pełny tekst źródłaStreszczenie:
In this study, thin films of PMMA Poly (methyl methacrylate)- Polyvinylidene fluoride(PMMA-PVDF), PMMA polymer and soluble PVDF polymer were prepared at (5%)Toluene and polymeric blends in 1:1 volume ratio of polymers and in different proportions of polymers. The studied films were prepared by the Spin coating method, and the optical parameters of the thin films were measured within a range (300-900)nm and the thickness of the films were constant (223 nm). Absorbance (A), linear absorption coefficient (α), refractive index (n), extinction coefficient (K), real and imaginary dielectric constant (∈r, ∈i), and optical energy gap Eg were studied, as the best edge of optical absorption was 5% PVDF, And electronic transmission between levels was direct transmission.
44
Chooseng, C., S. Chaipo i C. Putson. "Ferroelectric properties and breakdown strength of layer-by-layer poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and polyurethane (PU) for energy storage application". Journal of Physics: Conference Series 2145, nr 1 (1.12.2021): 012043. http://dx.doi.org/10.1088/1742-6596/2145/1/012043.
Pełny tekst źródłaStreszczenie:
Abstract Ferroelectric polymers are one of the next- generation pulsed capacitor materials for the potential application in capacitive energy storage. This polymer with higher saturated polarization, smaller remnant polarization, and higher electrical breakdown are the most promising candidates. In this work, the dielectric properties and energy storage capacity of the bilayer polymer films of Poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and polyurethane (PU) were studied. These bilayer polymers were prepared by layer- by- layer method at the condition of variable layer thickness. The results show that the dielectric constants and the saturated polarization of the bilayer films increased, and bilayer films with P70/PU30 exhibit electrical high breakdown strength up to 379 V/μm. Moreover, enhanced energy storage density and the energy efficiency of the bilayer constrictors will be discussed for the capacitive energy storage polymers.
45
Chougule, Shivanand M., Anna Twinkle, Riya Thomas i Manoj Balachandran. "Quantifying the role of nanocarbon fillers on dielectric properties of poly(vinylidene fluoride) matrix". Polymers and Polymer Composites 30 (styczeń 2022): 096739112210875. http://dx.doi.org/10.1177/09673911221087597.
Pełny tekst źródłaStreszczenie:
Development of polymers with excellent dielectric properties is a challenge for advanced electronic devices. Impregnating conducting fillers like carbon nanoparticles can enhance the dielectric constant, retaining low loss due to its compatibility and favorable polarization within the polymer matrix. The multifunctional characteristics of coal-derived nanocarbon can improve permittivity and facilitate large-scale production at a lower cost. The incorporation of coal-based nanocarbon in the polymer matrix and its dielectric response is seldom investigated. In this work, different ratios (10:90, 50:50, 90:10 by weight) of nanocarbon/PVDF composite are prepared via a simple solution casting technique. The dielectric measurements show that nanofillers’ addition significantly augments the dielectric constant value, which is ∼3 times (50:50 composite) higher than pure PVDF. The uniform distribution of 50% filler within the polymer matrix impeded the seepage of charge at the interface and enhanced the permittivity via polarization of accumulated charges. The composite also exhibited balanced dielectric loss that is essential for energy storage applications.
46
Yin, Xiaodong, Yali Qiao, Matthew R. Gadinski, Qing Wang i Chuanbing Tang. "Flexible thiophene polymers: a concerted macromolecular architecture for dielectrics". Polymer Chemistry 7, nr 17 (2016): 2929–33. http://dx.doi.org/10.1039/c6py00233a.
Pełny tekst źródłaStreszczenie:
Highly flexible and transparent free-standing films can be readily obtained from oligothiophene-containing norbornene polymers and their hydrogenated derivatives prepared by ROMP. The rigidness/softness of the polymer backbone and polar side chains dictate dielectric properties.
47
You, Yong, Chenhao Zhan, Ling Tu, Yajie Wang, Weibin Hu, Renbo Wei i Xiaobo Liu. "Polyarylene Ether Nitrile-Based High-k Composites for Dielectric Applications". International Journal of Polymer Science 2018 (10.07.2018): 1–15. http://dx.doi.org/10.1155/2018/5161908.
Pełny tekst źródłaStreszczenie:
Flexible polymer-based composites exhibiting high dielectric constant as well as low dielectric loss have been intensively investigated for their potential utilization in electronics and electricity industry and energy storage. Resulting from the polar -CN on the side chain, polyarylene ether nitrile (PEN) shows relatively high dielectric constant which has been extensively investigated as one of the hot spots as dielectric materials. However, the dielectric constant of PEN is still much lower than the ceramic dielectrics such as BaTiO3, TiO2, and Al2O3. In this review, recent and in-progress advancements in the designing and preparing strategies to obtain high-k PEN-based nanocomposites are summarized. According to the types of the added fillers, the effects of organic fillers, dielectric ceramic fillers, and conductive fillers on electric properties of PEN-based composites are investigated. In addition, other factors including the structures and sizes of the additive, the compatibility between the additive agent and the PEN, and the interface which affects the dielectric properties of the obtained composite materials are investigated. Finally, challenges facing in the design of more effective strategies for the high-k PEN-based dielectric materials are discussed.
48
Martyniuk, G. V., i O. I. Aksimentyeva. "Influence of conductive polymer filler on electrical conductivity and microhardness of composites with dielectric polymeric matrices". Chernivtsi University Scientific Herald. Chemistry, nr 818 (2019): 80–86. http://dx.doi.org/10.31861/chem-2019-818-11.
Pełny tekst źródłaStreszczenie:
Nowadays special attention is given to the so-called "smart-materials" or "intellectual" materials, which have the ability to purposefully change their physical and physical-chemical properties depending on changing external conditions. Сonductive conjugated polymers - polyaniline (РАNi) and its derivatives may alter their properties in response to external action - exhibit sensory sensitivity, electrochromic, thermochromic and solvachromic effects. When creating РАNi composites with industrial polymer matrices, an important issue is to determine the physical and mechanical properties, in particular, of microhardness as a material strength characteristic. Composite samples were obtained by the method of thermal pressing of highly dispersed powders of conductive polymers dispersed in polymer matrices. The mechanical properties of the composites were studied by the method of measuring microhardness and boundary microhardness on a Heppler consistometer. The determination of the electrical conductivity of the composites in the molded samples was determined by the standard 2-contact method at a temperature T = 293 K. The influence of the acid doped polyaniline (РАNi) as an conductive polymer filler оn on the microhardness of composites with polymer matrices of different structure (polyvinyl alcohol (PVA), polymethylmethacrylate (PMMA), polybuthylmethacrylate (PBMA), epoxy resin ED-20) was studied. It is found that the nature of the interaction between the polymer matrix and the conductive polymer filler depends on its content and the structure of the matrix, which is manifested in the growth of microhardness for composites PBMA – РАNi and ED-20 - РАNi and its reduction for composites PVA– РАNi at the contents of the filler 5-20 %. The dielectric polymer matrix preserves the properties inherent in both high polymers (high elasticity, thermoplasticity) and the semiconductor nature of the electrical conductivity inherent in the conjugated polymers. The value of the specific conductivity of the composites obtained well correlated with changes in microhardness, which is a confirmation of the enhancing or loosening nature of the interaction between the polymer matrix and the conductive polymeric filler.
49
MARTYNІUK, Galyna, i Olena AKSIMENTYEVA. "INFLUENCE OF CONDUCTIVE POLYMER FILLER ON ELECTRICAL CONDUCTIVITY AND MICROHARDNESS OF COMPOSITES WITH DIELECTRIC POLYMERIC MATRICES". Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2020, nr 60 (25.02.2020): 14–21. http://dx.doi.org/10.37827/ntsh.chem.2020.60.014.
Pełny tekst źródłaStreszczenie:
Nowadays special attention is given to the so-called “smart-materials” or “intellectual” materials, which have the ability to purposefully change their physical and physical-chemical properties depending on changing external conditions. Conductive conjugated polymers–polyaniline (РАNi) and its derivatives may alter their properties in response to external action–exhibit sensory sensitivity, electrochromic, thermochromic and solvatochromic effects. When creating РАNi composites with industrial polymer matrices, an important issue is to determine the physical and mechanical properties, in particular, the microhardness as a material strength characteristic. The composite samples were obtained by the method of thermal pressing of highly dispersed powders of the conductive polymers dispersed in the polymer matrices. The mechanical properties of the composites were studied by the method of measuring microhardness and boundary microhardness on a Heppler consistometer. The determination of the electrical conductivity of the composites in the molded samples was determined by the standard 2-contact method at a temperature T = 293 K. The influence of the acid doped polyaniline (РАNi) as a conductive polymer filler on the microhardness of composites with polymer matrices of different structure (polyvinyl alcohol (PVA), polymethyl methacrylate (PMMA), polybuthyl methacrylate (PBMA), epoxy resin ED-20) was studied. It is found that the nature of the interaction between the polymer matrix and the conductive polymer filler depends on its content and the structure of the matrix, which is manifested in the growth of microhardness for composites PBMA–РАNi and ED-20−РАNi and its reduction for composites PVA–РАNi at the contents of the filler 5−20 %. The dielectric polymer matrix preserves the properties inherent in both high polymers (high elasticity, thermoplasticity) and the semiconductor nature of the electrical conductivity inherent in the conjugated polymers. The value of the specific conductivity of the composites obtained well correlated with changes in microhardness, which is a confirmation of the enhancing or loosening nature of the interaction between the polymer matrix and the conductive polymeric filler.
50
Le, Quoc Toan, F. Drieskens, T. Conard, M. Lux, J. F. de Marneffe, H. Struyf i G. Vereecke. "Modification of Post-Etch Residues by UV for Wet Removal". Solid State Phenomena 187 (kwiecień 2012): 207–10. http://dx.doi.org/10.4028/www.scientific.net/ssp.187.207.
Pełny tekst źródłaStreszczenie:
In back-end of line processing, the polymer deposited on the dielectric sidewalls during the etch must be removed prior to subsequent processing steps to achieve high adhesion and good coverage of materials deposited in the etched features [1,. Typically, this is done by a combination of short plasma treatment and diluted wet clean, or by wet cleans alone. On the one hand, for porous dielectric stacks, a mild plasma treatment that preserves the integrity of the low-k dielectrics would not be sufficient to efficiently remove this residue. Furthermore, aqueous cleaning solutions is not efficient to achieve a complete removal without etching the underlying layer. Hence appropriate wet clean chemistries are needed to dissolve/decompose these polymers without etching the dielectric. On the other hand, analytical techniques available for direct characterization of sidewall polymer are limited. For a fast screening of potential chemistries capable of dissolving/removing polymer residues generated during the low-k etch, a fluoropolymer deposited on a blanket, checkerboard low-k substrate was used as a model polymer. In our recent study [, using X-ray photoelectron spectroscopy (XPS), it was shown that the polymer was composed of CF, CF2, and CF3 groups. This model polymer was found to be very similar to the polymer residue generated during the etch of the low-k stack using similar plasma. The present study mainly focused on the effect of UV treatment and the concentration of active component in wet clean solution on the structure change of the polymer and the enhancement of polymer removal.