Li, WenjingWenjingLiBuschhorn, Samuel T.Samuel T.BuschhornSchulte, KarlKarlSchulteBauhofer, WolfgangWolfgangBauhofer2023-10-272023-10-272011Carbon 49(6) 1955-1964 (2011)https://hdl.handle.net/11420/43915Visualization of embedded carbon nanotubes (CNTs) in polymer using a scanning electron microscope (SEM) has been established as a convenient technique to evaluate CNT dispersion. This technique is known as voltage contrast imaging and is different from material contrast and topographic contrast imaging. By investigating CNT/epoxy composites the voltage contrast imaging theory is further understood. Trapping of electrons at the CNT/epoxy interface induces a local potential difference which enhances the image contrast. By coating the composite with a polymer film of different thicknesses the imaging depth (i.e. from how deep the CNTs can be seen) is determined to be up to 250 nm, and is a function of the accelerating voltage of the SEM. Visibility of CNTs is found to be sensitive to the CNT dispersion and concentration, as well as to the accelerating voltage.en0008-62232011619551964Elsevier ScienceEngineering and Applied OperationsJournal Article10.1016/j.carbon.2010.12.069Journal Article