Helium ion microscopy of electrospun CNT-polymer composites

Arrangement and conformational interactions of carbon nanotubes (CNTs) and matrix upon electrospinning have been examined by surface-sensitive helium ion microscopy (He-IM). The enhanced surficial information is mostly a consequence of convoluted topographic sensitivity and reduced electrostatic charging, resulting from He ion-matter interactions. In addition, we have explored the correlation of findings by He-IM imaging with secondary electron microscopy (SEM), transmission electron microscopy (TEM), and near edge x-ray absorption fine structure (NEXAFS) spectroscopy; the latter encouraged by similar sampling depth profiles in both techniques. This study provides further evidence of strong conformational relations between filler and matrix (which we have reported recently) and of the presence of a tightly bound polymeric phase interaction between the CNT and the bulk matrix. We conclude that both the absence of electrostatic charging and enhanced surface sensitivity in He-IM offer a remarkable opportunity to study electrospinning dynamics in nanocomposites.