Video Experimental Relacionado
Updated: Jul 4, 2026
07:50
A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires
Published on: January 21, 2016
Resistencia eléctrica de largos alambres moleculares conjugados
Seong Ho Choi1, Bongsoo Kim, C Daniel Frisbie
1Department of Chemistry and Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
Science (New York, N.Y.)
|June 17, 2008
Resumen
Los investigadores estudiaron la resistencia eléctrica en los cables moleculares para comprender el transporte de carga. Observaron un cambio de túneles a mecanismos de salto a medida que aumentaba la longitud del cable, lo que afectaba la conductividad.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Comprender el transporte de carga en cables moleculares es crucial para el desarrollo de dispositivos electrónicos a nanoescala.
- La resistencia eléctrica es una propiedad clave influenciada por la longitud y estructura molecular.
Objetivo del estudio:
- Para investigar los mecanismos de transporte de carga en los cables moleculares conjugados.
- Para determinar cómo cambia la resistencia eléctrica con la longitud del alambre molecular y la interrupción de la conjugación.
Principales métodos:
- Medición de la resistencia y las características de tensión-corriente de los cables moleculares (1-7 nm de longitud).
- Variación sistemática de la longitud del cable para observar cambios en el régimen de transporte.
- Interrupción específica del sitio de la conjugación para evaluar su impacto en la conductividad.
Principales resultados:
- Se observó una transición del transporte de túneles al transporte de saltos en función de la longitud del cable, consistente con las predicciones teóricas.
- Se demostró que interrumpir la conjugación aumenta significativamente la resistencia en el régimen de salto, pero tiene un efecto mínimo en el régimen de túnel.
- Estableció una clara relación entre la longitud molecular, la arquitectura de enlaces y la conductividad eléctrica a nanoescala.
Conclusiones:
- Las mediciones de transporte a nanoescala aclaran las funciones fundamentales de la longitud molecular y la arquitectura de enlaces en la determinación de la conductividad molecular.
- Los hallazgos proporcionan información sobre el transporte eléctrico en películas de polímeros conjugados, abriendo caminos para el diseño de materiales avanzados.
- El estudio pone de relieve los distintos comportamientos de los mecanismos de transporte de túneles y saltos en los cables moleculares.
Videos de Conceptos Relacionados
01:22Resistivity
When a voltage is applied to a conductor, an electrical field is generated, and charges in the conductor feel the force due to the electrical field. The current density that results depends on the electrical field and the properties of the material. In some materials, including metals at a given temperature, the current density is approximately proportional to the electrical field. In these cases, the current density can be modeled as:
01:13Electrical Conductivity
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...
01:19Resistance
When a current moves through any conductor, the conductor causes some level of difficulty for the current to flow. The measure of that difficulty is known as the resistance of the material and is represented by R. Every material has its own resistance. In the case of conductors, heat is emitted whenever a current passes through them. Resistance depends on the resistivity of the material. Resistivity is a characteristic of the material used to fabricate electrical components, whereas the...
01:18Magnetic Field Due to Two Straight Wires
Consider two parallel straight wires carrying a current of 10 A and 20 A in the same direction and separated by a distance of 20 cm. Calculate the magnetic field at a point "P2", midway between the wires. Also, evaluate the magnetic field when the direction of the current is reversed in the second wire.
01:29Electrical Transport
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
01:25Resistance and Conductance
A conductor's DC resistance at a given temperature is influenced by its resistivity, length, and cross-sectional area. Resistivity is an inherent property of the conductor material, with annealed copper serving as the international standard for measurement. For instance, the resistivity of hard-drawn aluminum at 20 degrees Celsius is 61% of the standard conductivity of annealed copper.
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their length...
Various factors impact the resistance of a conductor. Spiraling in stranded conductors increases their length...