scholarly journals Study on the Structure and Dielectric Properties of Zeolite/LDPE Nanocomposite under Thermal Aging

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2108
Author(s):  
Bai Han ◽  
Chuqi Yin ◽  
Jiaxin Chang ◽  
Yu Pang ◽  
Penghao Lv ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Aging Time ◽  
Thermal Aging ◽  
Aging Treatment ◽  
Dielectric Strength ◽  
Breakdown Field ◽  
Scanning Calorimetry ◽  
Aging Resistance ◽  
The Stability ◽  
Breakdown Field Strength

Nanodoping is an effective way to improve the dielectric properties and the aging resistance of polyethylene. Nano-zeolite has a nano-level porous structure and larger specific surface area than ordinary nano-inorganic oxide, which can be used to improve dielectric properties of low-density polyethylene (LDPE) nanocomposite. The zeolite/LDPE nanocomposites were prepared and subjected to thermal aging treatment to obtain samples with different aging time. Using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the differential scanning calorimetry (DSC) test to study the microscopic and structure characteristics, it was found that nano-zeolite doping can effectively reduce the thermal aging damage to the internal structure of the nanocomposite; carbonyl and hydroxyl decreased significantly during the thermal aging time, and the crystallinity effectively improved. Nano-zeolite doping significantly improved the morphology and strengthened the aging resistance of the nanocomposite. In the dielectric strength test, it was found that nanodoping can effectively improve the direct current (DC) and alternating current (AC) breakdown field strength and the stability after the thermal aging. The dielectric constant of nanocomposite can be reduced, and the dielectric loss had no obvious change during the aging process. Moreover, the zeolite/LDPE nanocomposite with the doping concentration of 1 wt % had the best performance, for the nano-zeolite was better dispersed.

Effect of Post Plasma Treatment on Reliability and Dielectric Properties of SiOF Films Deposited by ECRCVD With SiF4 and O2

1997 ◽  
Vol 476 ◽  
Author(s):  
Seoghyeong Lee ◽  
Jae-Yoon Yoo ◽  
Kyunghui Oh ◽  
Jong-Wan Park
Keyword(s):  
Dielectric Properties ◽  
Plasma Treatment ◽  
Silicon Oxide ◽  
Treatment Time ◽  
Relative Dielectric Constant ◽  
Breakdown Field ◽  
Plasma Treatment Time ◽  
Breakdown Field Strength ◽  
Thermal Stability Of

AbstractThe effect of post plasma treatment on dielectric properties and reliability of fluorine doped silicon oxide (SiOF) films were investigated by measuring their C-V and I-V characteristics, XPS, AFM, and AES. The post plasma treatment of SiOF films was carried out in-situ at 300 °C in the deposition chamber. In this research, when the post plasma treatment time increased, we obtained the following results: (1) The etch rate of SiOF films decreased from 80Å/sec to 10Å/sec. (2) Surface roughness of the plasma treated SiOF films was increased due to the ion bombardment effect of the plasma. (3) The refractive index and relative dielectric constant increased from 1.391 to 1.461 and 3.14 to 3.9, respectively, due to the changes of surface chemistry by the post plasma treatment. (4) The leakage current density of SiOF films prepared by ECRCVD using SiF4 and O2 was less than 1 × 10−9A/cm2. (5) The breakdown field strength increased from 3.5 MV/cm to 8 MV/cm. (6) The thermal stability of the Cu/TiN/SiOF/Si system remained stable up to 600 °C.

scholarly journals Effects of Cold Rolling and Aging Treatment on the Properties of Cu-Be Alloy

2019 ◽  
Vol 9 (4) ◽  
pp. 4500-4503
Author(s):  
M. I. Mohamed
Keyword(s):  
Cold Rolling ◽  
Aging Time ◽  
Aging Treatment ◽  
Exothermic Peak ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Cold Rolling Reduction ◽  
Cold Rolled ◽  
Precipitated Phases ◽  
Dsc Curves

The effects of precipitated phases during aging treatment on the properties of the Cu-Be alloy have been extensively studied. In this study, the effect of cold rolling on the precipitated phases of the Cu-Be alloy compared with non-deformed alloy during isothermal and low heating rate aging of 20C/min have been investigated. Hardness changes, differential scanning calorimetry (DSC), dilatation analysis, and transmission electron microscopy (TEM) were used in this study. Hardening and contraction were strongly increased at an early aging time for the cold rolled Cu-Be alloy. In addition, the DSC curves revealed an exothermic peak from the γ΄΄ phase. This peak increased and shifted to lower aging time by increasing the cold rolling reduction. In addition, the hardness remarkably increased at lower aging temperatures for the cold rolled specimens. The contraction from the dilatation curves and the exothermic peaks shifted to lower aging temperatures in cold rolled specimens. The hardening of Cu-Be alloy is believed to be from the γ΄ phase, and the contraction and the first exothermic peak in DSC curves from γ΄΄ phase. TEM observations are in a good agreement with the above explanation and strongly revealed that γ΄΄ and γ΄ phases were highly accelerated by the effect of cold rolling

scholarly journals Research on Mechanical, Physicochemical and Electrical Properties of XLPE-Insulated Cables under Electrical-Thermal Aging

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Dongxin He ◽  
Tao Zhang ◽  
Meng Ma ◽  
Wenjie Gong ◽  
Wei Wang ◽  
...  
Keyword(s):  
Power Systems ◽  
Aging Time ◽  
Degradation Mechanism ◽  
Dielectric Strength ◽  
Breakdown Field ◽  
Insulation Material ◽  
Oxidation Induction Time ◽  
Cable Insulation ◽  
Characteristic Index ◽  
Xlpe Cable

The stabilization of cross-linked polyethylene (XLPE) cables is crucial to the safe working of power systems. In order to investigate the aging characteristics of cable insulation in the process of operation, 10 kV XLPE cables were electrically-thermally aged at an AC voltage of 26.1 kV and three temperatures: 103°C, 114°C, and 135°C. Cable samples at five aging stages were cut into slices and tested to determine their mechanical, physicochemical properties and dielectric strength. The changes in these properties were analyzed in terms of aging time. The mechanical strength and oxidation induction time have the same changing trend of decrease, because the chemical bonds of the cable insulation material are fractured when the XLPE cable is aged. The AC space charge presented a trend of gradual accumulation with aging time. The breakdown field strength after AC voltage application decreases monotonically with aging time, which could be a characteristic index to evaluate the degradation degree of the cable insulation. This research contributes to the comprehension of degradation mechanism and discovery of aging assessment criteria, which is of great significance in assessments of insulation properties and fault detection on power cables.

scholarly journals Influence of film stretching on crystalline phases and dielectric properties of a 70/30 mol% poly(vinylidenefluoride-tetrafluoroethylene) copolymer

2020 ◽  
Vol 10 (05) ◽  
pp. 2050023
Author(s):  
Thulasinath Raman Venkatesan ◽  
Anna A. Gulyakova ◽  
Reimund Gerhard
Keyword(s):  
Dielectric Properties ◽  
Polyvinylidene Fluoride ◽  
Ferroelectric Phase ◽  
Mechanical Analysis ◽  
Dielectric Relaxation Spectroscopy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystalline Phases ◽  
The Stability ◽  
Dissipation Losses

Polyvinylidene fluoride (PVDF)-based copolymers with tetrafluoroethylene (P(VDF-TFE)), trifluoroethylene (P(VDF-TrFE)) or hexafluoropropylene (P(VDF-HFP)) are of strong interest due to the underlying fundamental mechanisms and the potential ferro-, pyro- and piezo-electrical applications. Their flexibility and their adaptability to various shapes are advantageous in comparison to inorganic ferroelectrics. Here, we study the influence of stretching temperature on the crystalline phases and the dielectric properties in P(VDF-TFE) films by means of Dielectric Relaxation Spectroscopy (DRS), Fourier-Transform InfraRed spectroscopy (FTIR), Wide-Angle X-ray Diffraction (WAXD), Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA). Especially, the effect of stretching and the influence of the temperature of stretching on the mid-temperature ([Formula: see text] transition are studied in detail. The results show that stretching has a similar effect as that on PVDF, and we observe an increase in the fraction of ferroelectric [Formula: see text]-phase with a simultaneous increment in both melting point ([Formula: see text] and crystallinity ([Formula: see text] of the copolymer. While an increase in the stretching temperature does not have a profound impact on the amount of ferroelectric phase, the stability of the ferroelectric phase seems to improve — as seen in the reduction of the Full Width at Half Maximum (FWHM) of the WAXD peaks in both parallel and perpendicular directions to the molecular chain axis. The observation is also supported by the reduction of dissipation losses with an increase in stretching temperature — as seen in DRS measurements. Finally, both stretching itself and the temperature of stretching affect the various molecular processes taking place in the temperature range of the [Formula: see text] transition.

scholarly journals Effect of Particles Size on Dielectric Properties of Nano-ZnO/LDPE Composites

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 5 ◽  
Author(s):  
YuJia Cheng ◽  
Liyang Bai ◽  
Guang Yu ◽  
Xiaohong Zhang
Keyword(s):  
Field Strength ◽  
Crystal Habit ◽  
Experimental Result ◽  
Breakdown Field ◽  
Specimen Thickness ◽  
Scanning Calorimetry ◽  
Nano Zno ◽  
Zno Particles ◽  
Ldpe Composites ◽  
Breakdown Field Strength

The melt blending was used to prepare 3 wt% ZnO/low density polyethylene (ZnO/LDPE) nanocomposites in this article. The effect of different inorganic ZnO particles doping on the dielectrical property and crystal habit of LDPE matrix was explored. The nanoparticles size was 9 nm, 30 nm, 100 nm, and 200 nm respectively. Scanning electron microscope (SEM) was used to characterize ZnO nanoparticles whereas differential scanning calorimetry (DSC) was used to make thermal characterization of the samples. Besides, the AC (alternating current), DC (direct current breakdown characteristics and electrical conductivity of the nanocomposites was studied in this article. The experimental results showed that nano-ZnO/LDPE composites had the advantages such as small crystal size, high crystallization rate and crystallinity owing to nano-ZnO particles doping, when doping nano-ZnO particles size was 30 nm, the ZnO/LDPE nanocomposite crystallinity crest value 39.77% appeared. At the mean time, the DC and AC breakdown field strength values of composites were 138.0 kV/mm and 340.4 kV/mm respectively. They were the maximal values which improved 8.24% and 13.85% than LDPE. The AC breakdown field strength of samples decreased with specimen thickness increase. The DC breakdown field strength of LDPE and ZnO/LDPE composites were greater than AC breakdown field strength. From the conductivity experimental result it could be seen that when the experimental temperature and electric field intensity rose, the current density and conductivity of ZnO/LDPE composites increased with the enlargement of ZnO particles size. But the values were less than which of LDPE.

Assessment of Reliability of cap layers used in Cu-Black DiamondTM Interconnects

2003 ◽  
Vol 766 ◽  
Author(s):  
Ahila Krishnamoorthy ◽  
N.Y. Huang ◽  
Shu-Yunn Chong
Keyword(s):  
Dielectric Layer ◽  
Dielectric Breakdown ◽  
Copper Ions ◽  
Dielectric Strength ◽  
Time Dependent ◽  
Breakdown Field ◽  
Field Range ◽  
Time Dependent Dielectric Breakdown ◽  
Voltage Ramp ◽  
Low K

AbstractBlack DiamondTM. (BD) is one of the primary candidates for use in copper-low k integration. Although BD is SiO2 based, it is vastly different from oxide in terms of dielectric strength and reliability. One of the main reliability concerns is the drift of copper ions under electric field to the surrounding dielectric layer and this is evaluated by voltage ramp (V-ramp) and time dependent dielectric breakdown (TDDB). Metal 1 and Metal 2 intralevel comb structures with different metal widths and spaces were chosen for dielectric breakdown studies. Breakdown field of individual test structures were obtained from V-ramp tests in the temperature range of 30 to 150°C. TDDB was performed in the field range 0.5 – 2 MV/cm. From the leakage between combs at the same level (either metal 1 or metal 2) Cu drift through SiC/BD or SiN/BD interface was characterized. It was found that Cu/barrier and barrier/low k interfaces functioned as easy paths for copper drift thereby shorting the lines. Cu/SiC was found to provide a better interface than Cu/SiN.

scholarly journals The Hydrothermal Stability and the Properties of Non- and Strongly-Interacting Rh Species over Rh/γ, θ-Al2O3 Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Guanghao Cheng ◽  
Gurong Shen ◽  
Jun Wang ◽  
Yunhao Wang ◽  
Weibo Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Apparent Activation Energy ◽  
Aging Time ◽  
Reaction Path ◽  
Aging Treatment ◽  
Hydrothermal Stability ◽  
Hydrothermal Aging ◽  
Strongly Interacting

The present work reports the effects of γ-, θ-phase of alumina on the hydrothermal stability and the properties of non- and strongly-interacting Rh species of the Rh/Al2O3 catalysts. Comparing to γ-Al2O3, θ-Al2O3 can not only reduce the amount of occluded Rh but also better stabilize Rh during hydrothermal aging treatment. When the aging time was prolonged to 70 h, all the non-interacting Rh was transformed into strongly-interacting Rh and occluded Rh. The XPS results indicated that non- and strongly-interacting Rh might exist in the form of Rh/Rh3+ and Rh4+, respectively. CO-NO reaction was chosen as a probe reaction to research more information about non- and strongly-interacting Rh. The two Rh species had similar apparent activation energy (Eapp) of 170 kJ/mol, which indicated that non- and strongly-interacting Rh follow the same reaction path. The non-interacting Rh was removed from aged samples by the acid-treated method, and obtained results showed that only 2.5% and 4.0% non-interacting Rh was maintained in aged Rh/γ-Al2O3 and Rh/θ-Al2O3.

scholarly journals Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 607
Author(s):  
Carolina Hermida-Merino ◽  
Fernando Pardo ◽  
Gabriel Zarca ◽  
João M. M. Araújo ◽  
Ane Urtiaga ◽  
...  
Keyword(s):  
Polymer Membranes ◽  
Small Addition ◽  
Polymeric Membranes ◽  
Synthesis And Characterization ◽  
Complete Disappearance ◽  
Optical Profilometry ◽  
Scanning Calorimetry ◽  
Exfoliated Graphene ◽  
The Stability ◽  
Scanning Electron

In this work, polymeric membranes functionalized with ionic liquids (ILs) and exfoliated graphene nanoplatelets (xGnP) were developed and characterized. These membranes based on graphene ionanofluids (IoNFs) are promising materials for gas separation. The stability of the selected IoNFs in the polymer membranes was determined by thermogravimetric analysis (TGA). The morphology of membranes was characterized using scanning electron microscope (SEM) and interferometric optical profilometry (WLOP). SEM results evidence that upon the small addition of xGnP into the IL-dominated environment, the interaction between IL and xGnP facilitates the migration of xGnP to the surface, while suppressing the interaction between IL and Pebax®1657. Fourier transform infrared spectroscopy (FTIR) was also used to determine the polymer–IoNF interactions and the distribution of the IL in the polymer matrix. Finally, the thermodynamic properties and phase transitions (polymer–IoNF) of these functionalized membranes were studied using differential scanning calorimetry (DSC). This analysis showed a gradual decrease in the melting point of the polyamide (PA6) blocks with a decrease in the corresponding melting enthalpy and a complete disappearance of the crystallinity of the polyether (PEO) phase with increasing IL content. This evidences the high compatibility and good mixing of the polymer and the IoNF.

Plasticizer effect on dielectric properties of poly(methyl methacrylate)/titanium dioxide composites

2021 ◽  
pp. 096739112110147
Author(s):  
Ufuk Abaci ◽  
H Yuksel Guney ◽  
Mesut Yilmazoglu
Keyword(s):  
Dielectric Constant ◽  
Titanium Dioxide ◽  
Dielectric Properties ◽  
Methyl Methacrylate ◽  
Pure Pmma ◽  
Segmental Mobility ◽  
Scanning Calorimetry ◽  
Poly Methyl Methacrylate ◽  
Casting Technique ◽  
Lcr Meter

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.

scholarly journals Novel Polyimide/Copper-Nickel Ferrite Composites with Tunable Magnetic and Dielectric Properties

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1646
Author(s):  
Corneliu Hamciuc ◽  
Mihai Asandulesa ◽  
Elena Hamciuc ◽  
Tiberiu Roman ◽  
Marius Andrei Olariu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Nickel Ferrite ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Broadband Dielectric Spectroscopy ◽  
Copper Nickel ◽  
Low Dielectric ◽  
Magnetic Remanence ◽  
Polyimide Matrix ◽  
Ferrite Composites

Heat-resistant magnetic polymer composites were prepared by incorporating cerium-doped copper-nickel ferrite particles, having the general formula Ni1-xCuxFe1.92Ce0.08O4 (x: 0.0, 0.3, 0.6, 1.0), into a polyimide matrix. The effects of particle type and concentration on the thermal, magnetic, and electrical properties of the resulting composites were investigated. The samples were characterized by FTIR, scanning electron microscopy, X-ray diffractometry, thermogravimetric analysis, differential scanning calorimetry, vibrating sample magnetometer, and broadband dielectric spectroscopy. The composites exhibited high thermal stability, having initial decomposition temperatures between 495 and 509 °C. Saturation magnetization (Ms), magnetic remanence (Mr), and coercivity (Hc) were found in range of 2.37–10.90 emu g−1, 0.45–2.84 emu g−1, and 32–244 Oe, respectively. The study of dielectric properties revealed dielectric constant values of 3.0–4.3 and low dielectric losses of 0.016–0.197 at room temperature and a frequency of 1 Hz.

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