Small-angle X-ray scattering is the diffuse scattering of electrons to X-rays in the small Angle range near the original beam. Small-angle scattering occurs in all materials with non-uniform electron density on the nanometer scale. 

1.Application of SAXS in particle size distribution SAXS is widely used to determine the particle size and particle size distribution of nano-powders. The particle size analysis results reflect neither grains nor aggregates, but the size of primary particles. The particle size distribution of nanometer zirconia was measured by X-ray small Angle scattering method. The histogram of particle size distribution was obtained by testing and data processing.

2.Orientation characterization SAXS can intuitively characterize materials with orientation. FIG. 4 and 5 represent the SAXS and schematic diagram of the synthesized oriented carbon nanotubes. As can be seen from the SAXS diagram, the two bright spots with left and right symmetry indicate the high orientation of the carbon nanotubes, and the peak position corresponds to the size structure of the carbon nanotubes, while the randomly dispersed carbon nanotubes do not have such patterns.

So far, SAXS technology has been successfully applied to some aspects of microstructure characterization of materials, and it is of certain theoretical and practical significance to further study the theoretical methods and applications of SAXS.