CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yu Zeng,Shipeng Rao,Chenhan Xiong,Guoping Du,Zhaoyang Fan,Nan Chen
Dielectric polymer composites with conducting fillers would have great potential for diverse applications if their severe leakage loss could be addressed. In this regard, ternary composites using both ceramic and conducting materials as fillers might be an enabler for high dielectric constant and low dielectric loss. Herein, ternary composites with both Ti 3 C 2 T x MXene conducting nanosheets and CaCu 3 Ti 4 O 12 (CCTO) dielectric particles embedded in silicone rubber were studied. It was found that a ternary composite with 1.2 wt% (0.40 vol%) Ti 3 C 2 T x MXene and 12 wt% (2.58 vol%) CCTO could provide an overall superior performance that include a high dielectric constant of 8.8, low dielectric loss of less than 0.0015, good thermal stability up to 450 °C, and excellent mechanical properties with tensile strength of 569 kPa, elastic module of 523 kPa and elongation at break of 333%. The outstanding performance is attributed to the improved uniform dispersion and good interfacial compatibility of mixed fillers in the polymer matrix , suggesting ternary composites might be a better option over their binary counterparts in preparing high performance dielectric composites.
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2026
·
IF 29.1
Zekai Zhuang,Renlu Han,Yafei Hou,Qixiong Zhang,Jiancheng Yu,Na Li,Geng Wang,Jie Fu,Zhaozheng Deng,Hongwei Song,Yifei Qi,Keqi Tang
Ultrasound (US) induced piezoelectric catalytic therapy is an emerging cancer treatment method. However, the development and optimization of piezoelectric catalyst remain the major challenge. Herein, we have converted the classical dielectric material CaCu 3 Ti 4 O 12 (CCTO) into an efficient piezoelectric material through oxygen vacancy (V O ) engineering, enabling piezoelectric catalytic-driven cascade tumor therapy. The introduction of V O results in strong polarization and a robust piezoelectric coefficient. Density functional theory (DFT) calculations reveal that V O acts as an electron trap to suppress the recombination of electron and hole, enhancing the catalytic efficiency. The piezoelectric effect can “open” the cell membrane, facilitating the materials influx and triggering reactive oxygen species (ROS) storm. Meanwhile, the cavitation effect of US and tumor cell over-expressed glutathione (GSH) accelerate Cu and Ca release, causing intracellular ions overload. ROS and Ca ions damage mitochondria to evoke apoptosis, which accordingly shuts down the Cu + outflow pathway and expedites cuproptosis. Moreover, ROS and GSH depletion triggers ferroptosis. This process establishes a positive feedback loop mechanism. Transcriptome sequencing confirms the activation of cell death-related pathways. This study represents the first paradigm to create piezoelectricity through V O in CCTO for tumor therapy, advancing the applications of quadruple perovskites in tumor treatment.
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2023
·
IF 5.4
Pu Mao,Congbin Zeng,Yongguang Guo,Gang Lu,Qingsong Yan,Zhiyong Liu,Bing Xie,Yingying Zhao,Kun Guo,Lixue Zhang
Tuning the electrical heterogeneity of CaCu 3 Ti 4 O 12 (CCTO) ceramic is extremely important to improve its properties. In this work, the CCTO ceramics with enhanced dielectric and nonlinear properties were obtained by the introduction of nano ZnO based on the electrical heterogeneity modulation strategy. As a result, all the CCTO-ZnO samples show the colossal dielectric constant of 10 4 –10 5 at room temperature. Meanwhile, the dielectric constant of CCTO-ZnO samples exhibits better stability in a wide frequency range from 10 1 Hz to 10 5 Hz and over a temperature scope of 30–210 °C. Most importantly, the x = 0.04 sample presents a relatively lower room-temperature dielectric loss of about 0.07 at 10 3 Hz. Furthermore, the breakdown field strength accompanied by the nonlinear coefficient of CCTO-ZnO ceramics is also improved. The enhancement of dielectric and nonlinear behaviors in these ceramics is mainly ascribed to the tunable electrical heterogeneity as per the internal barrier layer capacitor (IBLC) model.
✓ 已验证
DOI
高影响因子
THIN SOLID FILMS
·
2023
·
IF 2.1
Renzhong Xue,Liuyang Zhao,Ziyang Chen,Binbin Cao,Chunyu Yuan,Yifan Xiao
In the present work, the optical and dielectric properties, microstructures, and nonlinear electrical performances were systematically investigated for Ca 1-x Cr x Cu 3 Ti 4 O 12 ( x = 0.00 - 0.40) thin films prepared on Pt/Ti/SiO 2 /Si substrates using the sol-gel method. X-ray photoelectron spectroscopy (XPS) verified that Cr 3+ and Cr 6+ were present in the thin films. Additionally, the content of secondary phase of titanium oxide (TiO 2 ) increased, the grain size decreased, and the surface roughness improved with the increase in the doped content of Cr. Due to the reduced grain size and oxygen vacancy concentration, the optical energy band gap increased from 2.92 to 3.54 eV. The change in the dielectric constants (Ɛ r ) of the thin films followed the internal barrier layer capacitor model. Doping was found to decrease the dielectric loss (tan δ) and enhance the nonlinear properties, which was due to the presence of TiO 2 secondary phase, high density, reduced grain size, incremental potential barrier height and grain boundary resistance. The Ca 0.8 Cr 0.2 Cu 3 Ti 4 O 12 thin film had a high Ɛ r of around 9340, low tan δ of around 0.012 at 1 kHz, nonlinear coefficient of about 4.64, and breakdown field of ca. 89 kV/mm. These results indicated that the doping of an appropriate amount of Cr could effectively modify the microstructure of CaCu 3 Ti 4 O 12 thin films and improve their optical and electrical properties.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Wenning Qi,Liuyang Li,Ruolin Han,Yanbin Hou,Zheng Zhou,Guang-Xin Chen,Qifang Li
Using high-dielectric inorganic ceramics as fillers can effectively increase the dielectric constant of polymer-based composites. However, a high percentage of fillers will inevitably lead to a decrease in the mechanical toughness of the composite materials. By introducing high aspect ratio copper calcium titanate (CaCu3Ti4O12) nanowires (CCTO NWs) and graphene as fillers, the ternary poly(vinylidene fluoride) (PVDF)-based composites (CCTO NWs–graphene)/PVDF with a significant one-dimensional orientation structure were prepared by hot stretching. CCTO NWs and graphene are arranged in a directional manner to form a large number of microcapacitor structures, which significantly improves the dielectric constant of the composites. When the ratio of CCTO NWs and graphene is 0.2 and 0.02, the oriented composites have the highest dielectric constant, which is 19.3% higher than the random composites, respectively. Numerical simulations reveal that the introduction of graphene and the construction of the one-dimensional oriented microstructure have a positive effect on improving the dielectric properties of the composites. This study provides a strategy to improve the dielectric properties of composite materials by structural design without changing the filler content, which has broad application prospects in the field of electronic devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qing Shao,Haike Yang,Yingxi Luo,Pan Yang,Liying Long,Yiqun Chen,Zizheng Liu,Feng Wu,Pengchao Xie,Jun Ma
A new activation technology for sulfite (S(IV)) using a perovskite CaCu 3 Ti 4 O 12 (CCTO) catalyst has been proposed to remediate the As(III) polluted water. When 0.05 g·L −1 CCTO and 0.4 mmol·L −1 S(IV) were mixed, 90.6% of As(III) could be removed in 30 min at an initial pH of 8.0. Dissolved oxygen played an indispensable role in the reaction. CCTO can interact with S(IV) via a heterogeneous catalytic route on its surface. Electrochemical characterization indicated that the electron transfer process between the surface Cu/ Ti atoms and S(IV) ions evoked the activation of S(IV), leading to the generation of SO 4 •− , which played a dominant role in the oxidation of As(III). Density functional theory (DFT) calculations have disclosed the spontaneous adsorption of sulfite on CCTO surface. A kinetics study determined the steady-state concentration of SO 4 •− to be 4.29 × 10 −14 mol·L −1 , which reacts with As(III) with a second-order reaction rate constant of 3.83 × 10 10 L·mol −1 ·s −1 . Furthermore, the CCTO catalyst was highly reusable, the structure of which did not significantly alter during the reaction. Therefore, the CCTO/S(IV) system is a promising and efficient advanced oxidation technique for the purification of As(III) in water.
研究领域:
环境科学
·
催化化学
·
水处理技术
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 10
·10336-10341
·
IF 1.798
Wu Shuang,Liu Pei,Lai Yuanming,Guan Weiming,Huang Zihan,Han Jiao,Xiang Yao,Yi Wei,Zeng Yiming
The Ba 2+ doped ceramics of Ca 1−x Ba x Cu 3 Ti 4 O 12 (x = 0.005, 0.01, 0.03, 0.05 and 0.1) were sintered via conventional solid-state reaction at 1050 °C for 8 h in air. The microstructure and electric properties of Ba 2+ doping ceramics were investigated. The lattice parameters of Ca 1−x Ba x Cu 3 Ti 4 O 12 (CBCTO) ceramics decreased with the Ba 2+ doping, and Ba 1.31 Ti 8 O 16 as secondary phase was confirmed at x = 0.1. The doping of Ba 2+ resulted in uniformly distribution of small size grain (~4 μm). All the doped samples showed lower value of dielectric constant than CaCu 3 Ti 4 O 12 (CCTO), due to low resistivity of the grain boundary with the Ba 2+ doped samples. The nonlinear coefficient and breakdown field were significantly enhanced by Ba 2+ doping.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 5.6
Hao Zu,Chuanfeng Wang,Hui Liu,Jian Bian,Yuan Feng,Hui Huang,Laiming Wei,Guohua Cao
Due to the elevated sintering temperature, CaCu 3 Ti 4 O 12 ceramics are unsuitable for co-firing with copper electrodes, which has notable advantages including low production cost, high conductivity and broad high-frequency applicability. Therefore, the sintering of CaCu 3 Ti 4 O 12 ceramics should be conducted at temperatures below 1083 °C (the melting point of Cu) and under protecting atmosphere to prevent the oxidation of Cu. In this paper, CaCu 3 Ti 4 O 12 ceramics were sintered at only 1000 °C in high-purity N 2 , then reoxidized at 800 °C in air to restore their electrical properties. Among them, Ge 4+ -Ni 2+ co-doped CaCu 3 Ti 4 O 12 ceramics exhibited significantly increased grain-boundary resistivity, resulting in substantially decreased dielectric loss (about 0.055 at 1 kHz), while still remaining a large dielectric constant of 9.4 × 10 3 . Additionally, the nonlinear coefficient and breakdown strength field were also improved to values of 3.3 and 1360 V/cm, respectively. The results provide a promising candidate material for multilayer capacitor-varistor devices with Cu internal electrode.
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Yunpeng Qu,Yulin Wu,Jiada Wu,Kai Sun,Runhua Fan
Metacomposites with simultaneous epsilon-negative and mu-negative property have drawn tremendous attentions due to their promising applications in electromagnetic field. Herein, Ni/CaCu 3 Ti 4 O 12 (Ni/CCTO) metacomposites were prepared by low-temperature pressureless sintering method. It was observed that Ni chains were gradually interconnecting to each other with increasing Ni content, and a percolation behavior was observed. Epsilon-negative property was obtained above percolation threshold attributing to the synergistic effect of induced electric dipole and low-frequency plasma oscillation in Ni networks, which was explained by the superposition of Drude and Lorentz model. Mu-negative property was observed above ∼34 MHz and ∼120 MHz for 60 wt% and 70 wt% Ni/CCTO composites respectively, which may originate from the combined effects of diamagnetic response, domain wall motion and gyromagnetic spin rotation. Hence, simultaneous epsilon-negative and mu-negative property at radio-frequency region was realized in Ni/CCTO metacomposites. Besides, the composites presented hopping conduction behavior, and then changed into metal-like conduction behavior with increasing Ni content. The impedance response of Ni/CCTO composites clarified the correlation between epsilon-negative and inductive character. This work could broaden the scope of metacomposites and pave its way to potential applications of electromagnetic shielding, novel antenna, and high- k capacitors.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Qingguo Chi,Xubin Wang,Changhai Zhang,Qingguo Chen,Minghua Chen,Tiandong Zhang,Liang Gao,Yue Zhang,Yang Cui,Xuan Wang,Qingquan Lei
In this paper, the one-dimensional (1D) Al2O3 nanofibers (Al2O3 NFs), CaCu3Ti4O12 nanofibers (CCTO NFs), and core–shell CaCu3Ti4O12@Al2O3 nanofibers (CCTO@Al2O3 NFs) were prepared via electrospinning technique. The surface modification with dopamine (PDA) was employed for the above three kinds of nanofibers before being filled the PVDF matrix, which can improve their dispersion and compatibility with the matrix. The microstructure, dielectric properties, leakage current density, breakdown strength, and energy storage performance of composites with three kinds of filler, CCTO NFs/PVDF, Al2O3 NFs/PVDF, and CCTO@Al2O3 NFs/PVDF, were systematically investigated. By comparing the three composites, it can be found that energy storage density of CCTO@Al2O3 NFs/PVDF were enhanced compared to that of pure PVDF, which can be attributed to improvement of polarization and electric breakdown strength. The energy density of 8.46 J/cm3 at 340 kV/mm was obtained for 4 vol % CCTO@Al2O3 NFs/PVDF nanocomposites, which is 230% larger than that of PVDF (3.68 J/cm3 at 330 kV/mm). This study provides a method for preparing high energy storage PVDF-based composite film which can be used for the next generation of dielectric capacitors.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
ACS Applied Electronic Materials
·
2019
·
IF 0
Yuping Liu,Liuyang Li,Meijiao Guo,Zheng Zhou,Guang-xin Chen,Qifang Li
A core–shell structured organic–inorganic hybrid, that is, a hyperbranched aromatic polyamide (HB-Pa)-coated calcium copper titanate nanowire (CCTO NW), was prepared through a two-step solvent-thermal method followed by in situ polymerization. The morphology and structure of CCTO NWs and HB-Pa-coated CCTO NWs (HB-Pa@CCTO NWs) were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The high dielectric constant composites with notable mechanical properties were fabricated based on the epoxy resin (EP) matrix by using the core–shell structured HB-Pa@CCTO NWs as dielectric filler. At the same mass fraction, the composites filled with HB-Pa@CCTO NWs exhibited more excellent dielectric and mechanical properties than those filled only with synthesized CCTO NWs. At 40 wt % HB-Pa @CCTO NWs content, a relatively high dielectric constant (18) and a low dielectric loss (0.05) at 1 kHz were synchronously obtained. The simultaneous increases in dielectric and mechanical properties resulted from the strengthened interaction between the inorganic ceramic NWs and polymers, thereby resulting in the better dispersion of NWs in the EP matrix.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 20
·7962-7969
·
IF 8.067
Junhao Jiang,Jinpeng Li,Yantai Zhang,You Yuan,Xiaoyun Liu,Peiyuan Zuo,Jun Qian,Qixin Zhuang
A large number of studies have confirmed that encapsulating an insulating shell on the surface of high-permittivity nanofillers can effectively improve the energy storage performance of polymer-based dielectric nanocomposites. Regrettably, there is currently no research to explore how changes in the insulation of a shell will affect the dielectric properties. In this work, three inorganic oxides with systematically varied bandgaps, including SiO2 (SO), HfO2 (HO) and TiO2 (TO), were selected as the shells of CaCu3Ti4O12 nanowires (CCTO NWs). Then the nanowires were added to the polyetherimide (PEI) matrix to yield polymer nanocomposites. The insulating shell can not only inhibit the free charge migration, but also alleviate the electric field distortion in the nanocomposites, thereby dramatically reducing the dielectric loss and improving the breakdown strength. The larger the bandgap of the shell, the more prominent the performance. Consequently, the highly insulating shell enables the nanocomposites to achieve higher discharged energy density (Ud). Moreover, the core–shell structured CCTO/PEI nanocomposites exhibit more excellent dielectric thermal stability. At 150 °C, the Ud of 5 vol% SO@CCTO NWs/PEI can reach 3.73 J cm−3, showing potential as a high-temperature dielectric material.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）