Determination of power-law attenuation coefficient and dispersion spectra in multi-wall carbon nanotube composites using Kramers-Kronig relations

Joel Mobley; Richard A Mack; Joseph R Gladden; P Raju Mantena

doi:10.1121/1.3125323

Determination of power-law attenuation coefficient and dispersion spectra in multi-wall carbon nanotube composites using Kramers-Kronig relations

J Acoust Soc Am. 2009 Jul;126(1):92-7. doi: 10.1121/1.3125323.

Authors

Joel Mobley¹, Richard A Mack, Joseph R Gladden, P Raju Mantena

Affiliation

¹ Department of Physics and Astronomy, University of Mississippi, University, Mississippi 38677, USA. jmobley@olemiss.edu

PMID: 19603865
DOI: 10.1121/1.3125323

Abstract

Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths investigated and up (>0.2 mm). Using Kramers-Kronig relations, the attenuation and dispersion data were found to be consistent with a power-law attenuation model with a range of exponents from y=1.12 to y=1.19 over the measurement bandwidth. The attenuation coefficients of the respective samples are found to decrease with increasing MWCNT content and a similar trend holds also for the dispersion. In contrast, the mean phase velocities for the samples rise with increasing MWCNT content indicating an increase in the mechanical moduli.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.