Observatorio de I+D+i UPM

Memorias de investigación
Research Publications in journals:
The peculiar electrical response of liquid crystal-carbon nanotube systems as seen by impedance spectroscopy
Year:2015
Research Areas
  • Liquid crystals,
  • Fullerence and nanotubes of coal
Information
Abstract
Conductive nanoparticles, especially elongated ones such as carbon nanotubes, dramatically modify the electrical behavior of liquid crystal cells. These nanoparticles are known to reorient with liquid crystals in electric fields, causing significant variations of conductivity at minute concentrations of tens or hundreds ppm. The above notwithstanding, impedance spectroscopy of doped cells in the frequency range customarily employed by liquid crystal devices, 100 Hz?10 kHz, shows a relatively simple resistor/capacitor response where the components of the cell can be univocally assigned to single components of the electrical equivalent circuit. However, widening the frequency range up to 1 MHz or beyond reveals a complex behavior that cannot be explained with the same simple EEC. Moreover, the system impedance varies with the application of electric fields, their effect remaining after removing the field. Carbon nanotubes are reoriented together with liquid crystal reorientation when applying voltage, but barely reoriented back upon liquid crystal relaxation once the voltage is removed. Results demonstrate a remarkable variation in the impedance of the dielectric blend formed by liquid crystal and carbon nanotubes, the irreversible orientation of the carbon nanotubes and possible permanent contacts between electrodes.
International
Si
JCR
Si
Title
Journal of Physics D-Applied Physics
ISBN
0022-3727
Impact factor JCR
2,521
Impact info
Datos JCR del año 2013
Volume
48
Journal number
From page
375302
To page
375302-8
Month
AGOSTO
Ranking
Participants
  • Autor: Amanda García García (UPM)
  • : Ricardo Vergaz (Universidad Carlos III)
  • Autor: J.F. Algorri (Universidad Carlos III)
  • Autor: Morten Andreas Geday (UPM)
  • Autor: Jose Manuel Oton Sanchez (UPM)
Research Group, Departaments and Institutes related
  • Creador: Departamento: Tecnología Fotónica y Bioingeniería
S2i 2019 Observatorio de investigación @ UPM con la colaboración del Consejo Social UPM
Cofinanciación del MINECO en el marco del Programa INNCIDE 2011 (OTR-2011-0236)
Cofinanciación del MINECO en el marco del Programa INNPACTO (IPT-020000-2010-22)