相关实验视频
Updated: Jul 1, 2025
08:52
Characterizing Electron Transport through Living Biofilms
Published on: June 1, 2018
8.4K
在直流和交流电场下的乙烯基纤维素膜中的电导机制
Jesús G Puente-Córdova1, Juan F Luna-Martínez1, Nasser Mohamed-Noriega1
1Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Av. Universidad s/n, Cd. Universitaria, San Nicolás de los Garza 66455, Mexico.
Polymers
|March 13, 2024
概括
这项研究揭示了使用短暂电流和动态机械分析的乙基纤维素 (EC) 的介电性质. 这些发现表明,欧洲共同体 (EC) 是一个欧洲共同体.
科学领域:
- 聚合物科学 聚合物科学
- 介电光谱学 介电光谱学
- 材料科学 材料科学 材料科学
背景情况:
- 乙纤维素 (EC) 是一种多功能生物聚合物,在电子行业具有潜在的应用.
- 了解其介电行为对于优化其在电气和电子设备中的使用至关重要.
- 之前的研究已经探讨了EC的机械和热特性,但它在电场下的详细介电反应需要进一步研究.
研究的目的:
- 为了研究乙烯纤维素 (EC) 在直流 (DC) 电场下的介电行为.
- 为了将EC的粘弹性和玻璃过渡温度与其介电反应相关联.
- 开发一个数学模型来描述EC中的短暂电流,并分析其电导机制.
主要方法:
- 在真空中,在直流电场 (~10^7 V/m) 下进行过渡电流实验.
- 动力机械分析 (DMA) 用于确定粘弹性反应和玻璃过渡温度 (~402 K).
- 交替电流 (AC) 导电性测量是在玻璃过渡温度以上的20 Hz至2 MHz频率范围内进行的.
主要成果:
- 与EC的玻璃过渡相关的机械放松在402K左右被观察到.
- 建议使用分数微分方程和米塔格-莱弗勒函数的数学框架来描述短暂电流.
- 在玻璃过渡温度以上的电导被归因于聚合物链的细分运动,这表明了电子应用的潜力.
结论:
- 乙纤维素的介电性行为受到其分子运动性和能量消散率的影响,正如分数计算所描述的那样.
- 聚合物-电极接口和散装材料现象都对导电机制有所贡献.
- 乙基纤维素表现出有希望的电气性能,将其定位为电气,电子和机电电子应用的可行候选者.
相关概念视频
01:13Electrical Conductivity
1.1K
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
1.1K
01:16Electrostatic Boundary Conditions
475
Consider an external electric field propagating through a homogeneous medium. When the electric field crosses the surface boundary of the medium, it undergoes a discontinuity. The electric field can be resolved into normal and tangential components. The amount by which the field changes at any boundary is given by the difference between the field components above and below the surface boundary.
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
The surface integral of an electric field is given by Gauss's law in integral form and is related to...
475
01:17Theory of Metallic Conduction
1.3K
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
1.3K
01:23Induced Electric Fields
3.7K
The fact that emfs are induced in circuits implies that work is being done on the conduction electrons in the wires. What can possibly be the source of this work? We know that it’s neither a battery nor a magnetic field, as a battery does not have to be present in a circuit where current is induced, and magnetic fields never do any work on moving charges. The source of the work is in fact an electric field that is induced in the wires. For example, if a stationary conductor is placed in a...
3.7K
01:20Electric Field Inside a Conductor
6.0K
When a conductor is placed in an external electric field, the free charges in the conductor redistribute and very quickly reach electrostatic equilibrium. The resulting charge distribution and its electric field have many interesting properties, which can be investigated with the help of Gauss's law.
Suppose a piece of metal is placed near a positive charge. The free electrons in the metal are attracted to the external positive charge and migrate freely toward that region. This region then...
Suppose a piece of metal is placed near a positive charge. The free electrons in the metal are attracted to the external positive charge and migrate freely toward that region. This region then...
6.0K
01:26Electric Field at the Surface of a Conductor
4.7K
Consider a conductor in electrostatic equilibrium. The net electric field inside a conductor vanishes, and extra charges on the conductor reside on its outer surface, regardless of where they originate.
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
4.7K