SmallAngleXrayScattering

Small Angle X-ray Scattering, often abbreviated as SAXS, is a powerful experimental technique used to study the structure of matter on the nanometer scale. It relies on the coherent elastic scattering of X-rays by inhomogeneities in electron density within a sample. When X-rays pass through a material, they can be scattered in various directions. SAXS specifically analyzes the scattering patterns observed at very small angles, typically less than 5 degrees, relative to the incident X-ray beam. These small angles correspond to the diffraction from larger structures, such as particles, polymers, or aggregates, with characteristic dimensions in the range of approximately 1 to 100 nanometers.

The intensity of the scattered X-rays as a function of the scattering angle provides information about the size, shape, and distribution of these nanostructures. By analyzing the scattering profile, researchers can determine parameters like the radius of gyration, which is a measure of the size of a particle, or the Porod invariant, related to the surface area of scattering objects. SAXS is a versatile technique applicable to a wide range of materials, including biological macromolecules like proteins and DNA, synthetic polymers, colloids, and porous materials. It is a non-destructive method that can be performed on samples in various states, such as solutions, suspensions, or solid films. The interpretation of SAXS data often involves comparison with theoretical models or direct structure reconstruction methods.