Quantification of ion trapping effect of carbon nanomaterials in liquid crystals

Abstract

We have determined the ion trapping coefficients of carbon nanomaterials in liquid crystals through the analysis of capacitance–voltage response. The ion trapping coefficient is defined as the ability to trap impurity ions for each carbon nanomaterial and can be used as a referable value to select proper carbon nanomaterials as dopants in liquid crystals. The characterized nanomaterials include multi-wall carbon nanotubes, carbon nanofibers, carbon nanocoils, single-wall carbon nanotubes and fullerenes, respectively. It is found that the multi-wall carbon nanotubes with a tube length of 5–15 μm have the largest ion trapping coefficient and hence serve as the best dopant to suppress the liquid crystal hysteresis.