AFM Capabilities in Characterization of Nanoparticles: From Angstroms to Microns

摘要

Scanning Probe Microscopy (SPM), invented 25 years ago, is now routinely employed as a surface characterization technique. Atomic Force Microscopy (AFM) is the most widely used form of SPM, since AFM can be used in ambient conditions with minimal sample preparation. AFM measures three-dimensional topography profiles and images with unprecedented resolution from micron to sub-Angstrom scales. AFM is well suited for individual particle characterization, especially for measurements of volume, height, size, shape, aspect ratio and particle surface morphology. Statistical distributions for a large set of particles can be generated through single-particle analysis techniques (i.e. ensemble-like information). Single-particle analysis techniques with AFM are generally more cost and time-effective than analysis with Scanning Electron Microscopy (SEM). AFM offers resolution that is comparable to or greater than SEM or Transmission Electron Microscopy (TEM). Also, AFM directly measures parameters such as height and volume and produces images that can be displayed in a 3D format.