Methodology for the characterization of the microstructure of nanocomposite polymeric foams using X-ray microtomography

Polymeric foams used in electromagnetic shielding applications are characterized using X-ray microtomography. These foams contain a conductive nanometric reinforcement, carbon nanotubes, but the scale of characterization described here is that of the microscopic cells. Although nanotube dispersion is important for the final properties of the material, the structure and distribution of the porosity also play a role in terms of dielectric constant and conductivity. Unfortunately, cell wall thinness and limited resolution of laboratory microtomographs makes poper cell identification difficult. Therefore we present a new statistical method based on the 3D autocorrelation function, that allows to some extent to measure mean cell size and structure anisotropy.