Carbon nanofibers (CNFs) and carbon nanotubes (CNTs) have become wonder products for industrial use because of their unique characteristics such as thermal and electrical conductivity, heat distortion resistance, mechanical reinforcement, and high surface area. As a result, engineered carbon nanomaterials are being produced at a rapid rate for use in the aerospace, automotive, environmental, computer, and recreational industries. However, certain characteristics of carbon nanomaterials make them a cause for concern. CNFs and CNTs are tiny, cylindrical or cone-shaped, manufactured forms of carbon and their structure can be similar to that of asbestos. The effects of asbestos exposure include severe lung fibrosis or scarring, lung cancer, including cancer of the lining of the lungs, or pleura, called mesothelioma.
In this study, five samples of carbon nanomaterials are aerosolized and sampled through a cascade impactor to determine their size distribution and geometric mean diameter (GMD). The samples are evaluated using a scanning electron microscope with energy dispersive x-ray analysis (SEM/EDS) to determine their morphology and metal content. Seven samples, including three CNFs and four CNTs of different lengths and diameters, are tested for PAH concentration using gas chromatography/mass spectrometry (GC/MS). The carbon nanomaterials used in this study are produced via chemical vapor deposition (CVD), which uses metal catalysts such as Fe, Co, and/or Ni. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) is used to quantify trace metals in the carbon nanomaterials.