Small Angle X-ray diffraction (SAXD) is mainly used to determine the spacing of very large crystal faces or the structure of thin films.

1. Polymer particle size and distribution, polymer quality, shape;

In polymer chemistry, SAXS is used to determine the radius of rotation (Rg) of polymers or self-assemblies. Rg is a quantity that characterizes the mass distribution around the particle center. For example, for micelles or proteins, at the same molecular weight, their microstructure may be different, for example, the opening or folding of the protein will be reflected in the radius of rotation.

2. Characterize geometric parameters such as particle size, shape and distribution

SAXS is a useful tool for characterizing porous materials. For example, in ordered mesoporous materials (ordered mesoporous carbon, ordered mesoporous silicon), the structural information can be given by SAXS characterization methods, and the d value can be calculated by d=2π/q formula.