Terahertz Time Domain Spectroscopy for Characterizing Properties of Carbon Nanotube Yarns

Carbon nanotube (CNT) yarns are made of aligned filaments of structured carbon such as single or multi-walled carbon nanotubes. They are flexible, strong, thermally and electrically conductive in the axial direction. Here we report on using THz time-domain spectroscopy to characterize Miralon ${ }^{\circledR}$ yarn manufactured by Huntsman corporation. As CNTs strongly absorb and reflect THz radiation polarized along the CNT axis, THz TDS provides a rapid, non-destructive approach to characterize CNT fiber bundle alignment in the yarn materials. It can be used to study correlations between alignment and yarn tenacity and other properties.