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conductivity BEHAVIOR OF IONIC Al(OH)_3-POLYACRYLAMIDE HYBRIDS IN AQUEOUS SOLUTIONS

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Chinese Journal of Polymer Science 2004年第2期22卷 169-174页

作者：钱锦文 Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 China

The conductivity behavior of Al(OH)3-acrylamide hybrid polyacrylamide (hybrid PAAm) in distilled water was studied. A discontinuity phenomenon of the conductivity (k) versus concentration (c) curve of the hybrid PAAm in a certain concentration regime is found. This phenomenon is dependent on the molecular weight of the hybrid PAAm and on the particle size and content of the Al(OH)3 colloid in the hybrid PAAm. This phenomenon was accounted for assuming ionization of the hybrid PAAm.

关键词： Ionic hybrid polyacrylamide Viscosity conductivity

conductivity of Poly(methyl methacrylate)/Polystyrene/Carbon Black and Poly(ethyl methacrylate)/Polystyrene/Carbon Black Ternary Composite Films

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Chinese Journal of Polymer Science 2020年第3期38卷 288-297,I0007页

作者： Hua-Gen Xu Mu-Chao Qu Ya-Min Pan Dirk WSchubert Institute of Polymer Materials Friedrich-Alexander-University Erlangen-NurembergMartensstr.791058 ErlangenGermany College of Materials Science and Engineering The Key Laboratory of Material Processing and Mold of Ministry of EducationZhengzhou UniversityZhengzhou 450002China Bavarian Polymer Institute Dr.Mack-Strasse 7790762 FiirthGermany

Poly(methyl methacrylate)(PMMA)/polystyrene(PS)/carbon black(CB)and poly(ethyl methacrylate)(PEMA)/PS/CB ternary composite films were obtained using solution casting technique to investigate double percolation effect.In both PMMA/PS/CB and PEMA/PS/CB ternary composite films,the CB particles prefer to locate into PS phase based on the results of calculating wetting coefficient,which is also confirmed by SEM images.The conductivity of the films was investigated,and the percolation threshold(￠c)of both ternary composite films with different polymer blend ratios was determined by fitting the McLachlan GEM equation.conductivity of PMMA/PS/CB ternary composite films showed a typical double percolation effect.However,due to the double emulsion structure of PEMA/PS polymer blends,the PEMA/PS/CB ternary composite films(PEMA/PS=50/50)showed a higher￠c,even CB only located in PS phase,which conflicts with the double percolation effect.A schematic diagram combined with SEM images was proposed to explain this phenomenon.

关键词： Double percolation effect conductivity Ternary composite films Compatibility

Metallic Aluminum Suboxides with Ultrahigh Electrical conductivity at High Pressure

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Research 2023年第2期2022卷 25-32页

作者： Tianheng Huang Cong Liu Junjie Wang Shuning Pan Yu Han Chris J.Pickard Ravit Helled Hui-Tian Wang Dingyu Xing Jian Sun National Laboratory of Solid State Microstructures School of PhysicsAnd Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China Department of Materials Science Metallurgy University of Cambridge27 Charles Babbage RoadCambridge CB3 OFSUK Advanced Institute for Materials Research Tohoku University2-1-1 KatahiraAobaSendai 980-8577Japan Institute for Computational Science Center for Theoretical Astrophysics CosmologyUniversity of ZurichSwitzerland

Aluminum,as the most abundant metallic elemental content in the Earth's crust,usually exists in the form of alumina(Al_(2)O_(3)).However,the oxidation state of aluminum and the crystal structures of aluminum oxides in... 详细信息

关键词： oxides conductivity interior

conductivity of (NH4)3[CrMo6O24H6]·7H2O Treated by Nd Chemistry-Heated Diffused Permeation

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Journal of Materials Science & Technology 2005年第5期21卷 776-778页

作者： Xin LI Zhonghua LI Yuzhi GAO Maomao ZHAO Yuanru GUO Baibin ZHOU Department of Applied Chemistry Harbin Institute of Technology Harbin 150001 China Department of Chemistry Harbin Normal University Harbin 150080 China

Rare earth co-permeation of （NH4）3[CrMo6O24H6]·7H2O was reported and the conductivity of （NH4）3[CrMo6O24H6] was improved by 6.734×10^9 times. X-ray fluorescence spectrometry （XRF）, thermogravimetry-differential thermal analysis （TG-DTA）, X-ray diffraction （XRD） have been used to character （NH4）3[CrMo6O24H6]·7H2O and permeated sample. Experimental results showed that Nd could be permeated into the body of this sample and the XRD patterns showed great difference between （NH4）3[CrMo6O24H6]·7H2O and permeated sample. The structure of （NH4）3[CrMo6O24H6]·7H2O was destroyed and new compound MoN perhaps formed.

关键词： Rare earths （NH4）3[CrMo6O24H6]·7H2O Chemistry-heated diffused permeation conductivity

conductivity and dielectric studies on LiCeO_2

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Journal of Rare Earths 2010年第3期28卷 435-438页

作者： M.Prabu S.Selvasekarapandian A.R.Kulkarni G.Hirankumar C.Sanjeeviraja Department of Metallurgical Engineering and Material Science Indian Institute of Technology Bombay Department of Physics Kalasalingam University Department of Physics Alagappa University

LiCeO2 was prepared by a solid-state reaction method using microwave heat treatment and identified by X-ray diffractometry.LiCeO2 has monoclinic crystal structure whose conductivity and dielectric properties were studied over a range of frequency(42 Hz to 1 MHz) and temperatures(30-500 °C) using ac technique of complex impedance analyzer HIOKI 3532.Combined impedance and modulus plots were used as tools to analyze the sample behaviour as a function of frequency at different temperatures.The d.***.conductivity...

关键词： lithium-ion batteries impedance conductivity dielectric analysis complex modulus rare earths

conductivity enhancement by controlled percolation of inorganic salt in multiphase hexanoyl chitosan/polystyrene polymer blends

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Frontiers of Materials Science 2015年第2期9卷 132-140页

作者： Tan WlNIE Nur Syuhada MOHD SHAHRIL Faculty of Applied Sciences Universiti Teknologi MARA 40450 Shah Alam Malaysia

Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature （Tg） as well as the viscometric and morphological analyses. Selective localization of the lithium salt in hexanoyl chitosan phase as the percolation pathway enhanced the conductivity in the blends as compared to the neat hexanoyl chitosan. The ionic conductivity of a polymer electrolyte is described by σ = enp. Thus, estimation of charge carrier density （n） and mobility （μ） is important in order to assess the performance. In this work, these parameters are calculated using impedance spectroscopy and FTIR.

关键词： hexanoyl chitosan polystyrene polymer electrolyte conductivity perco-lation pathway

Violation of the T^(−1) Relationship in the Lattice Thermal conductivity of Mg_(3)Sb_(2) with Locally Asymmetric Vibrations

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Research 2020年第1期2020卷 750-759页

作者： Yifan Zhu Yi Xia Yancheng Wang Ye Sheng Jiong Yang Chenguang Fu Airan Li Tiejun Zhu Jun Luo Christopher Wolverton GJeffrey Snyder Jianjun Liu Wenqing Zhang State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Materials Genome Institute Shanghai UniversityShanghai 200444China Department of Materials Science and Engineering Northwestern UniversityIL 60208USA Max Planck Institute for Chemical Physics of Solids Dresden 01187Germany State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Department of Physics and Shenzhen Institute for Quantum Science&Engineering Southern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Lab for Computational Science and Materials Design and Shenzhen Municipal Key Lab for Advanced Quantum Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

Most crystalline materials follow the guidelines of T^(-1) temperature-dependent lattice thermal conductivity(κ_(L))at elevated temperatures.Here,we observe a weak temperature dependence ofκL in Mg_(3)Sb_(2),T^(-0:48) from theory and T-0:57 from measurements,based on a comprehensive study combining ab initio molecular dynamics calculations and experimental measurements on single crystal Mg_(3)Sb_(2).These results can be understood in terms of the so-called“phonon renormalization”effects due to the strong temperature dependence of the interatomic force constants(IFCs).The increasing temperature leads to the frequency upshifting for those low-frequency phonons dominating heat transport,and more importantly,the phononphonon interactions are weakened.In-depth analysis reveals that the phenomenon is closely related to the temperature-induced asymmetric movements of Mg atoms within MgSb_(4) tetrahedron.With increasing temperature,these Mg atoms tend to locate at the areas with relatively low force in the force profile,leading to reduced effective 3^(rd)-order IFCs.The locally asymmetrical atomic movements at elevated temperatures can be further treated as an indicator of temperature-induced variations of IFCs and thus relatively strong phonon renormalization.The present work sheds light on the fundamental origins of anomalous temperature dependence of κ_(L) in thermoelectrics.

关键词： phonon conductivity Locally

Harnessing Electrostatic Interactions for Enhanced conductivity in Metal-Organic Frameworks

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Research 2021年第1期2021卷 1543-1553页

作者： An-An Zhang Xiyue Cheng Xu He Wei Liu Shuiquan Deng Rong Cao Tian-Fu Liu Department of Chemistry School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefeiAnhui 230026China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China University of the Chinese Academy of Sciences Beijing 100049China

The poor electrical conductivity of metal-organic frameworks(MOFs)has been a stumbling block for its applications in many important fields.Therefore,exploring a simple and effective strategy to regulate the conductivity of MOFs is highly desired.Herein,anionic guest molecules are incorporated inside the pores of a cationic MOF(PFC-8),which increases its conductivity by five orders of magnitude while maintaining the original porosity.In contrast,the same operation in an isoreticular neutral framework(PFC-9)does not bring such a significant change.Theoretical studies reveal that the guest molecules,stabilized inside pores through electrostatic interaction,play the role of electron donors as do in semiconductors,bringing in an analogous n-type semiconductor mechanism for electron conduction.Therefore,we demonstrate that harnessing electrostatic interaction provides a new way to regulate the conductivity of MOFs without necessarily altering the original porous structure.This strategy would greatly broaden MOFs’application potential in electronic and optoelectronic technologies.

关键词： structure conductivity electrostatic

conductivity of CeO_2 Modified SrTiO_3 Ceramics

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Journal of Rare Earths 1995年第1期13卷 16-20页

作者：肖鸣山陈玲张成琚王希香 Shandong Univ Jinan China

The CeO2 modified SrTiO3 ceramics were prepared by conventional ceramic process. The SrTiO3 matrix and CeO2 additive were combined in following system:SrTiO3 +x(CeO2·TiO2), where x is the weight percent , of which x (wt%)=2,5, 10, 15, 20,25, and 30. The samples were sintered at 1400℃ for an hour in air. The Ce element in SrTiO3 ceramics is used as an impurity donor. The scanning electron microscopic (SEM) analysis and X-ray diffractive examination of SrTiO3 ceramics containing CeO2 indicated that there exists a Ce2O3 secondary phase (viz. glass phase) and it had solid solution solubility for impurities which decrease the semiconductive property of SrTiO3 ceramics , and weaken the oxidation of the surface of grain and thus increase the conductivity of the grains. The semiconducting ceramics process lightly distorted cubic structure at room temperature. This paper mainly gives a study of the conductivity of CeO2 modified SrTiO3 ceramics.

关键词： Semiconducting ceramics conductivity Secondary phase Distorted cubic structure