Assessment of particle distribution in particle-containing composite materials using an electron probe microanalyzer

Numerous filler particles are being developed and applied to improve the properties of conventional composite materials or to develop composite materials with additional functionalities. When filler particles are added to the polymer matrix of a fiber-reinforced composite material, the particles dispersed in the polymer resin can be filtered between fiber strands during the manufacturing process, which leads to a nonuniform particle distribution and material defects. Therefore, understanding and controlling such filtration phenomena has become a critical issue. In the present study, a new microscopic methodology for measuring the distribution of filler particles in fully cured composite parts using an electron probe microanalyzer (EPMA) is proposed. The distributions of spherical titanium dioxide particles and carbon nanotubes conjugated with silver nanoparticles as tracers were visualized by elemental mapping analysis. Furthermore, the concentrations were separately measured in the intratow and intertow regions by quantitative analysis.