Small-angle X-ray scattering (SAXS) is a non-destructive method to analyze nano-scale structures in liquids and solids. This method has advantages over other microscopy methods such as atomic force microscopy and transmission electron microscopy, because SAXS provides not only local but also integral information about the sample. Its principle is measuring of the intensity of x-rays scattered as a function of angle: the source emits an X-ray beam that interacts with the sample electron and dissipates on it. X-ray scattering works at different angles and the larger the particle, the smaller the scattering angle. SAXS analyzes the scattering at angles, which are usually less than 10° to study nanoparticles which size is D ∈ (1, 100) nm. Parameters of nanomaterials that can be determined using SAXS are shape, size, internal structure, crystallinity, porosity, orientation. The unique characteristics of this method are the ability to study biomolecules under physiological conditions (BioSAXS), and simple sample preparation.
In addition, this article includes a brief description of other research methods, such as GISAXS (Grazing-incidence small-angle X-ray scattering; to study thin films) and WAXS (Wide-angle X-ray scattering; for studying nanoparticle with size d < 1nm).
Application of SAXS: the study and analysis of biological materials (proteins, fats), disperse systems, emulsions, surfactants, metals, polymers, fibers, catalysts and many other).