Article
Materials Science, Ceramics
Keying Xue, Jialing Xie, Menglong Wang, Lingxia Li
Summary: The addition of Mn to BaTiO3-based ceramics significantly improves their dielectric properties and temperature stability. Experimental results and first-principle calculations reveal that the formation of new defect dipoles is responsible for the observed changes in dielectric properties. The Mn-doped ceramics exhibit high dielectric constant, large insulation resistivity, low dielectric loss, and excellent temperature stability.
CERAMICS INTERNATIONAL
(2023)
Article
Engineering, Chemical
Weijie Zhang, Penghao Sun, Bingxin Wang, Shuting Li, Bing Yi, Qingquan Liu, Hai Yang
Summary: This study developed a polarization-triggered strategy in polymeric semiconductors to enhance exciton dissociation efficiency by regulating dielectric constants. The results showed that the polarization of SpiroCMP-4 with high dipole moment significantly increased its dielectric constant and reduced exciton binding energy, leading to improved photocatalytic degradation of antibiotics in wastewater.
SEPARATION AND PURIFICATION TECHNOLOGY
(2024)
Article
Materials Science, Ceramics
Jie Fu
Summary: PNb9O25 ceramic was prepared using the sparking plasma sintering (SPS) method. The ceramic exhibited high dielectric constant, low dielectric loss, and high electrical conductivity, showing stable performance within a certain temperature range.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Physical
Huabo Huang, Wentao Mei, Yucong Wang, Juan Huang, Liang Li, Jiayou Ji, Chuanxi Xiong
Summary: A composite film with high dielectric performance was prepared by coating polyaniline onto the surface of boron nitride nano sheets and forming nitrogen-doped carbon. The inclusion of BN@NC effectively preserved the nanosheet structure and promoted the formation of β-PVDF, improving compatibility and enhancing interfacial polarization. The resulting sandwich-structured film exhibited significantly higher dielectric constant, breakdown strength, and energy density compared to pure PVDF film, showcasing its potential for low-cost and high-energy density dielectric composites.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Jun-Wei Zha, Yaya Tian, Ming-Sheng Zheng, Baoquan Wan, Xing Yang, George Chen
Summary: Polymer dielectrics are essential materials for high energy density film capacitors. However, commercial dielectric films lack high thermal stability required for harsh operating environments. Polyimide is a promising candidate for high-temperature energy storage dielectric materials due to its excellent thermal stability and insulation properties. This review discusses design strategies to enhance the energy storage properties of polyimide dielectric materials through polymer multiple structures, including short-range structures, remote structures, and higher-order structures. The introduction of highly polar groups, regulation of molecular segment structures, and blending methods of all-organic polyimide are deeply explored. Additionally, the development of computational simulation methods for high-temperature energy storage polyimide dielectrics is presented. The review concludes by summarizing the key challenges of using polyimide as a high-temperature energy storage dielectric material and exploring future development directions.
MATERIALS TODAY ENERGY
(2023)
Article
Materials Science, Multidisciplinary
T. Ahamed, A. Ahad, Mithun Kumar Das, M. A. Taher, Mohammad J. Miah, M. N. I. Khan
Summary: Polycrystalline Bi0.90Eu0.10Fe1-xVxO3 (BEFVO) ceramics were synthesized via solid-state reaction. The XRD pattern showed hexagonal crystal structures with impurity peaks. The doped BiFeO3 (BFO) exhibited greater stability than the parent BFO. The samples had varying crystallite sizes, densities, dielectric constant, resistivity, and magnetic properties depending on the V concentration.
RESULTS IN PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Chih-Cheng Kuo, Yan-Cheng Lin, Yu-Che Chen, Ping-Han Wu, Shinji Ando, Mitsuru Ueda, Wen-Chang Chen
Summary: This study extensively investigated the relationships between the structure and dielectric properties of polyimides, revealing highly correlated relationships between dielectric constant values and structural parameters such as fluorine content and volume polarizability. Additionally, a strong correlation was found between dissipation factor values and the imide group content. However, there were multiple positive trends in the relationship between dissipation factor values and volume dipole moment, attributed to the challenges in elucidating local molecular motions in the unit structure of polyimides.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Polymer Science
Pilwoo Lee, Hunsang Jung, Chan-Sei Yoo, Hyun Ho Lee
Summary: Due to the rapid development of high frequency wireless communication, a more robust and low power consumption substrate for printed circuit board (PCB) application is needed. In this study, modified resins based on styrene-maleic anhydride (SMA) copolymer were used to achieve a low dielectric constant substrate for the PCB application under ultrahigh frequencies. The low dielectric constant is attributed to the stereo-structure and conformational orientation of the carbon chains in the modified SMA copolymer.
Article
Materials Science, Composites
Omid Aghababaei Tafreshi, Zia Saadatnia, Shahriar Ghaffari-Mosanenzadeh, Tianhao Chen, Sophie Kiddell, Chul B. Park, Hani E. Naguib
Summary: This study presents the fabrication of novel polyimide composite aerogel films with tunable dielectric properties by incorporating graphene nanoplatelet fillers. The addition of graphene improved the nanostructure of aerogels, resulting in improved homogeneity and uniformity of the composite gel films. The inclusion of graphene nanoplatelets proved to be an effective strategy for improving the mechanical properties, machinability, and thermal stability of aerogels.
COMPOSITES COMMUNICATIONS
(2022)
Article
Polymer Science
Xiaojie He, Songyang Zhang, Yu Zhou, Feng Zheng, Qinghua Lu
Summary: This study predicted the dielectric constants of three types of fluorinated polyimides and investigated the impact of fluorine content on the dielectric constant. Principal component analysis revealed that molecular polarization and fluorine content are the dominant factors affecting the dielectric constant.
Article
Materials Science, Ceramics
Junwei Liu, Xin Wei, Yongfu Lian, Qiaoli Liu, Xingzu Xu, Dayong Lu
Summary: The structures and dielectric properties of Sr-modified Cu/Nb co-doped BaTiO3 ceramics were studied, showing changes in dielectric constant with Sr content at different frequencies, as well as the presence of dielectric relaxation and the influence of inhomogeneous structures in low temperature ranges.
CERAMICS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Khoe Van Nguyen, Shih-Yen Lin, Yia-Chung Chang
Summary: The transfer characteristics of p-doped graphene/monolayer-MoS2 heterostructure at 300 K were experimentally measured and analyzed based on a model calculation. The Poisson equation was discretized into multiple zones, and the Boltzmann transport equation was solved in the relaxation-time approximation using inelastic acoustic phonon scattering in the model. The relationship between the Dirac voltage and the Fermi energy was derived, and the results obtained without and with optical pumping agreed well with experimental data.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Polymer Science
Weikai Sun, Minhao Yang, Kun Peng, Yaqin Fu
Summary: The demand for high-speed communication at high frequency has led to the development of low-dielectric polymer films. Aromatic polyimide (PI) is commonly used in flexible circuit boards due to its excellent properties, but its dielectric constant is relatively high for high-frequency communication. To address this, a hyper-crosslinked polymer (HCP) was synthesized and blended with PI to form all-organic HCP/PI composite films. The porous structure of HCP helps to reduce the dielectric constant of the PI matrix. By adjusting the HCP content, the dielectric constant of the composite films can be effectively lowered in the desired frequency range. This method is simple and can be applied to other organic component-filled PI systems.
MACROMOLECULAR RAPID COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Shi-Yu Zhang, Teng Fu, Yue Gong, De -Ming Guo, Xiu-Li Wang, Yu-Zhong Wang
Summary: Two copolyesters containing phenyl or naphthyl structures were synthesized, and the effects of benzene and naphthalene mesogens on dielectric properties were investigated. The copolyesters containing naphthalene structure showed good comprehensive properties with high thermal stability, inherent flame retardance, low dielectric constant, and low dielectric loss. Naphthalene mesogen can more significantly reduce the dielectric loss at high frequency by reducing the density and mobility of polarizable groups, leading to limited dipole polarization. Therefore, a new strategy for designing low dielectric constant and low dielectric loss materials is proposed.
CHINESE CHEMICAL LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Rishi Pal, Sneh Lata Goyal, Ishpal Rawal, Vivek Gupta
Summary: The dielectric properties of in-situ polymerized polyaniline-multiwalled carbon nanotubes (PANI/MWCNTs) nanocomposite sample were analyzed as a function of temperature and applied frequency. The introduction of MWCNTs into the PANI matrix during polymerization and the reduction via chemical treatment with ammonia resulted in a lower conducting dielectric state. XRD pattern showed the semi-crystalline nature of the prepared sample. The dielectric constant increased with temperature and decreased with applied frequency, and the enhanced dielectric properties were attributed to the mobility of electric dipoles and reduced dc electrical conductivity due to the reduction of PANI/MWCNTs nanocomposite.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Polymer Science
Yuanzhang Jiang, Xuyi Wang, Yanting Han, Dakai Gong, Yingchun Gu, Lin Tan
Summary: In this study, FeCl3 and poly(acrylic acid) (PAA) were doped into waterborne polyurethanes (WPUs) to create multifunctional materials with self-healing and antimicrobial properties. WPU/Fe/PAA-5.5, containing 5.5 wt % PAA, exhibited excellent mechanical properties, strong self-healing capabilities, and an impressive antimicrobial rate of over 90%. These supramolecular films were also highly recyclable through hot-pressing.
Article
Polymer Science
Longyu Tian, Min Wang, Guangming Liao, Baoliang Liu, Sujuan Zhang, Yucheng Sun, Zhen Meng, Jintao Zhang, Zaijun Lu
Summary: Two kinds of benzoxazine monomers were synthesized and used to prepare polybenzoxazine anion exchange membranes (AEMs) with quaternary ammonium functionalization. The LQPBZ AEM exhibited better ion conductivity and alkaline stability.
Article
Polymer Science
Claire A. Lemarchand
Summary: This study investigates the shock behavior of three different polymers through molecular dynamics simulations. The results reveal specificities in the shock behavior of polymers, including deviations from the linear relation between shock velocity and particle velocity, as well as differences in shear stress relaxation behind the shock front. It is found that the deviation of the Hugoniot locus is related to the change in the relative contribution of bonding and non-bonding potential energies, while polymers with higher glass transition temperatures exhibit slower shear stress relaxation.
Article
Polymer Science
Zengquan Liu, Xiaochun Yin, He Zhang, Shuo Gao, Qinglin Kuang, Yanhong Feng
Summary: A powder solid-state extension (PSSE) technology was proposed to address the high melt viscosity issue of UHMWPE. By uniaxial extension and sintering in the solid state, a highly self-reinforced material was prepared. X-ray diffraction and scattering techniques were used to study the structural evolution during the PSSE process, and a solid-phase induced transformation model was established.
Article
Polymer Science
Zhike Li, Anyu Luo, Rui Zhou, Xin Li, Haiyan Li
Summary: A novel high temperature resistance IL@SiO2 nanocapsules were successfully prepared and their friction and wear properties in PA6 composites were studied. The addition of IL@SiO2 nanocapsules reduced the friction coefficient and wear rate without affecting the mechanical properties of PA6. The synergy between the IL core and SiO2 wall in the nanocapsules improved the self-lubricating performance of the PA6 composites.
Article
Polymer Science
Xin Liu, Xuhong Guo, Qi Liao
Summary: In this study, an algorithm for accurately estimating viscosity is developed using molecular dynamics simulations and the Green-Kubo formula. This algorithm can be applied to complex systems with long correlations, such as macromolecular and biological simulation systems.
Article
Polymer Science
Hao Pu, Yun-Lei Hou, Jing -Zhou Chen, Dong -Lin Zhao
Summary: The use of modified graphene improves the interfacial adherence of carbon fibers to epoxy resin, resulting in enhanced interfacial and bending properties of CF and matrix in CF/EP composites, as well as increased interlaminar shear strength and flexural strength.
Article
Polymer Science
Wei-Chung Ke, Jin-Wei Lin, Manohar Reddy Busireddy, Yueh-Hsing Lee, Jiun-Tai Chen, Chain-Shu Hsu
Summary: This study introduces a crosslinkable monomer, TAIC, to synthesize three crosslinked polyimide films, which exhibit improved thermal, mechanical, and dielectric properties. The introduction of TAIC enhances the tensile strength, reduces the dielectric constant and dielectric loss, and decreases the coefficient of thermal expansion of the polyimide films.
Article
Polymer Science
Alex Kwasi Kumi, Ruiling Fan, Ye Chen, Yumei Zhang
Summary: The difference in leaching of amylopectin from cellulose/amylopectin/1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) blends during regeneration in water and aqueous ethanol has been studied. Molecular dynamics simulations showed that the dissolution and regeneration mechanisms of amylopectin in [Bmim][Cl] are similar to cellulose in ionic liquids. Water regeneration leads to weak electrostatic interactions, resulting in high leaching of amylopectin. In contrast, ethanol-water interactions enhance electrostatic interactions among amylopectin chains, limiting amylopectin leaching in aqueous ethanol.
Article
Polymer Science
Xi Zeng, Junwei Zhou, Junbiao Peng, Chunsheng Zhang, Danling Wang, Yihu Song, Qiang Zheng
Summary: This study utilizes an oligomer deep eutectic solvent (DES) based on polyethylene glycol to regulate the vulcanization kinetics of rubber. The results show that the DES can accelerate vulcanization at low temperatures without affecting the crosslinking density and Mullins effect.
Article
Polymer Science
Qianqian Yue, Yongfei Peng, Xingjian Liu, Aihua He, Huarong Nie
Summary: The addition of metal deactivators can effectively suppress the aging of TBIR, prolong its lifespan, and have no negative effects on its physical and processing properties. These research findings are of great importance for improving the stability and aging resistance of polymers.
Article
Polymer Science
J. Gomez-Caturla, J. Ivorra-Martinez, R. Tejada-Oliveros, V Moreno, D. Garcia-Garcia, R. Balart
Summary: This work focuses on the development of environmentally friendly PLA formulations by using different esters derived from geraniol as plasticizers. The results show that these esters have good compatibility with PLA, and they can effectively enhance the elongation and plasticity of PLA, reduce its glass transition temperature, and slightly improve its water absorption capabilities.
Article
Polymer Science
Dandan Li, Zhaohui Lu, Zhao Ke, Ke Xu, Fengna Dai, Youhai Yu, Guangtao Qian, Chunhai Chen
Summary: In this study, cross-linked PI aerogel membranes with low dielectric constant and high moisture resistance were prepared by co-polymerization and scraping coating technology. The incorporation of fluorinated blocks and benzimidazole ring structures resulted in novel PI aerogel membranes with fascinating dielectric properties and outstanding moisture resistance.
Article
Polymer Science
Zhaoyang Chu, Qing Zhang, Haihua Luo, Han Zhou, Fapei Zhang, Wei Chen, Wenhua Zhang
Summary: Multi-physical fields solution processing strategy is a universal and facile method for preparing various conjugated polymer films and high-performance devices. In this study, we employed a combined microfluidic flow and ultrasonication strategy (FU) for processing CP solutions, and found a pronounced synergetic effect in promoting the pre-ordering of chains in solution. The conformation order and anisotropy of the solution were revealed through various characterizations. A non-classical nucleation model for polymer crystallization in non-equilibrium solution processing was confirmed. The roles of microfluidic flow and ultrasonication in chain aggregation and crystallization were addressed through multi-physical simulations. Compared to pristine solutions, the FU strategy showed improved solution anisotropy and crystallization kinetics, resulting in higher crystallinity in films and increased mobilities in OFET devices. The FU processing strategy provides a universal approach for regulating chain conformation and aggregation in conjugated polymer solutions.