Video Experimental Relacionado
Updated: Jul 11, 2026
12:20
Fabrication of Carbon Nanotube High-Frequency Nanoelectronic Biosensor for Sensing in High Ionic Strength Solutions
Published on: July 22, 2013
Extrema sensibilidad al oxígeno de las propiedades electrónicas de los nanotubos de carbono
1Department of Physics, University of California at Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Science (New York, N.Y.)
|March 10, 2000
Resumen
Los nanotubos de carbono de pared única exhiben una sensibilidad extrema a su entorno químico. Los gases adsorbidos alteran reversiblemente sus propiedades electrónicas, lo que afecta a su uso como sensores y potencialmente compromete las mediciones intrínsecas.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Nanotecnología La nanotecnología es la nanotecnología.
- Física de la materia condensada Física de la materia condensada
Sus antecedentes:
- Los nanotubos de carbono de pared única (SWCNT) poseen propiedades electrónicas únicas.
- La comprensión de las influencias ambientales en los SWCNT es crucial para su aplicación.
Objetivo del estudio:
- Para investigar el impacto del entorno químico en las propiedades electrónicas de SWCNT.
- Para explorar la sensibilidad de los SWCNT a los gases adsorbidos.
Principales métodos:
- Mediciones de transporte mediciones de transporte.
- Escaneo espectroscopia de túneles de exploración.
Principales resultados:
- Las propiedades electrónicas de SWCNT (resistencia, potencia termoeléctrica, densidad local de estados) son muy sensibles a la exposición al aire/oxígeno.
- Pequeñas concentraciones de gases adsorbidos pueden ajustar reversiblemente estos parámetros electrónicos.
- Los SWCNT semiconductores pueden exhibir un comportamiento metálico al exponerse al gas.
Conclusiones:
- Los SWCNT muestran potencial como sensores sensibles de gases químicos.
- Los efectos extrínsecos de la exposición al aire pueden alterar significativamente las propiedades medidas de los SWCNT preparados, lo que requiere una cuidadosa consideración.
Videos de Conceptos Relacionados
03:10Ionic Radii
Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...
02:55Exceptions to the Octet Rule
Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:
02:24Polar Covalent Bonds
Covalent bonds are formed between two atoms when both have similar tendencies to attract electrons to themselves (i.e., when both atoms have identical or fairly similar ionization energies and electron affinities). Nonmetal atoms frequently form covalent bonds with other nonmetal atoms. For example, the hydrogen molecule, H2, contains a covalent bond between its two hydrogen atoms. When two separate hydrogen atoms with a particular potential energy approach each other, their valence orbitals...
01:10Carbon-13 (¹³C) NMR: Overview
Carbon-13 is a naturally occurring NMR-active isotope of carbon with a low natural abundance of 1.1%. In contrast, carbon-12 is the most abundant isotope of carbon with zero nuclear spin. Therefore, it is NMR inactive. The gyromagnetic ratio of carbon-13 is smaller than that of protons. As a result, carbon-13 resonance is about 6000 times weaker than proton resonance. For a given magnetic field strength, the resonance frequency of carbon-13 is about one-fourth of the resonance frequency for...
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
01:04¹³C NMR: ¹H–¹³C Decoupling
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...