Authors: M. Zhao, B. Ming, P. Stutzman, G. Chen, X. Gu, C. Park, Y.C. Jean, T. Nguyen
Affilation: National Institute of Standards and Technology, United States
Pages: 9 - 12
Keywords: SPM, EFM, SEM, subsurface, polymer composites, CNT
Scanning Probe Microscopy (SPM) and Scanning Electron Microscopy (SEM) are two powerful techniques for surface characterization of nanostructures. With the development of nanotechnology, there is a growing need to nondestructively characterize nanostructures at the subsurface of materials, such as dispersion study of carbon nanotubes (CNTs) within polymer composites, which is beyond the capabilities of conventional SPM and SEM techniques. Here we report subsurface characterization of CNTs in polyimide composites using Electric Force Microscopy (EFM), a special type of SPM based on long-range electrostatic interactions [1, 2]; and poly-transparent SEM based on the charge contrast at the interface of CNTs and polymers . The effectiveness of these techniques is demonstrated by subsurface imaging of CNTs with different concentrations in polyimide composites using EFM technique alone (Figure 1) and combined EFM and SEM techniques at the same location of the sample (Figure 2). The optimal experimental parameters are extensively studied and new contrast mechanism for EFM and SEM subsurface imaging of CNTs in polymer matrix is proposed. Furthermore, these techniques can be universally applied to characterize high dielectric nanostructures in low dielectric polymer matrix, with a broad range of applications in nanotechnology.