AC-impedance response of multi-walled carbon nanotube/cement composites

Abstract AC-impedance spectroscopy (AC-IS) was combined with time-domain reflectometry (TDR) to investigate the impedance response of fiber-reinforced cement (FRC) composites with multi-walled carbon nanotubes (MWCNTs). In Nyquist plots (−imaginary impedance vs. +real impedance) three impedance arcs/features were observed, similar to Nyquist plots for macrofiber and microfiber FRCs. The intersection of the electrode arc and the intermediate frequency feature ( R DC (FRC)) corresponds to the DC resistance of the composite. The intersection of the two bulk features ( R cusp ) corresponds to the AC resistance of the composite. Reductions in ( R DC (FRC)) from the matrix resistance are indicative of a nanotube percolating network. Reductions in R cusp from the matrix resistance are indicative of a discontinuous fiber–fiber path. Both shifts increased with fiber loading. AC-IS measurements are therefore able to discriminate percolation vs. discontinuous fiber effects in CNT-FRCs, with the potential for characterizing dispersion issues (e.g., clumping/aggregation) in nanocomposites.

[1]  W Wood.  SARCOLOGY: A NEW MEDICAL SCIENCE. , 1893, Science.

[2]  Thomas O. Mason,et al.  A universal equivalent circuit model for the impedance response of composites , 2003 .

[3]  Thomas O. Mason,et al.  Impedance spectroscopy of fiber-reinforced cement composites , 2002 .

[4]  Xiaohua Zhao,et al.  Mechanical behavior and microstructure of cement composites incorporating surface-treated multi-walled carbon nanotubes , 2005 .

[5]  E. Garboczi,et al.  Impedance Spectra of Fiber-Reinforced Cement-Based Composites: A Modeling Approach , 2000 .

[6]  Deron A. Walters,et al.  Elastic strain of freely suspended single-wall carbon nanotube ropes , 1999 .

[7]  W. McCarter,et al.  The complex impedance response of fly-ash cements revisited , 2004 .

[8]  Edward J. Garboczi,et al.  Analysis of the impedance spectra of short conductive fiber-reinforced composites , 2001 .

[9]  A. Kulik,et al.  Mechanical properties of carbon nanotubes , 1999 .

[10]  Charles M. Lieber,et al.  Nanobeam Mechanics: Elasticity, Strength, and Toughness of Nanorods and Nanotubes , 1997 .

[11]  T. Mason,et al.  Assignment of features in impedance spectra of the cement-paste/steel system , 1998 .

[12]  A. Mukherjee,et al.  Single-wall carbon nanotubes as attractive toughening agents in alumina-based nanocomposites , 2003, Nature materials.

[13]  B. Ingram,et al.  Powder-Solution-Composite Technique for Measuring Electrical Conductivity of Ceramic Powders , 2003 .

[14]  H. Jennings,et al.  Dielectric amplification in cement pastes , 1997 .

[15]  James J. Beaudoin,et al.  Carbon Nanotubes and their Application in the Construction Industry , 2004 .

[16]  R. Ruoff,et al.  Strength and breaking mechanism of multiwalled carbon nanotubes under tensile load , 2000, Science.

[17]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[18]  J. Dolado,et al.  High-Performance Nanostructured Materials for Construction , 2004 .

[19]  A. Kulik,et al.  Mechanical properties of carbon nanotubes , 1999 .

[20]  H. Lezec,et al.  Electrical conductivity of individual carbon nanotubes , 1996, Nature.

[21]  Christian A. Martin,et al.  Formation of percolating networks in multi-wall carbon-nanotube–epoxy composites , 2004 .

[22]  E. Garboczi,et al.  Intrinsic Conductivity of Short Conductive Fibers in Composites by Impedance Spectroscopy , 2001 .

[23]  Bin Liu,et al.  A molecular mechanics approach for analyzing tensile nonlinear deformation behavior of single-walled carbon nanotubes , 2007 .