We investigate the shielding effectiveness and complex conductivity of single-walled carbon nanotubes (SWNT) distributed in a polyvinyl alcohol (PVA) matrix in the THz frequency range. SWNTs are dispersed in PVA matrices with varying SWNT content (keeping the thickness of SWNT/PVA film constant) using a slow-drying method, and terahertz time-domain spectroscopy (THz-TDS) is performed at room temperature in transmission geometry in the frequency range of 0.3–2.1 THz. The transmittance spectra show a possible application of SWNT/PVA composites as low-bandpass filters in the THz frequency region. Shielding effectiveness of all the samples is measured, and, at a particular probing frequency, they tend to follow a linear relationship with SWNT weight fraction in the polymer matrices. THz conductivity of the composite system is described in the light of a.c. hopping conduction.
© 2014 Optical Society of America
Original Manuscript: December 27, 2013
Revised Manuscript: February 7, 2014
Manuscript Accepted: February 7, 2014
Published: March 12, 2014
Debanjan Polley, Anjan Barman, and Rajib Kumar Mitra, "EMI shielding and conductivity of carbon nanotube-polymer composites at terahertz frequency," Opt. Lett. 39, 1541-1544 (2014)