The internal structure of single carbon fibers determined by simultaneous small- and wide-angle X-ray scattering

Simultaneous small-angle scattering and wide-angle diffraction using a sync hrotron radiation microbeam was applied for the first time to investigate s ingle carbon fibers in a position-resolved way. Taking into account the exa ct X-ray beam profile and examining the fibers in two scattering geometries allowed a discrimination between different models for the internal arrange ment of carbon layers and pores. For a fiber based on polyacrylnitrile the carbon layers were randomly oriented within the fiber cross section, wherea s in a mesophase-pitch based fiber the layers were arranged in a radial str ucture.