Figure 1. Schematic Diagram of the Principle of X-ray Small-Angle Scattering (SAXS)
The basic principle of X-ray scattering is that when X-rays irradiate a sample, if there are regions of nanometer-scale electron density heterogeneity within the sample, X-ray scattering signals will appear at certain angles around the incident beam. Microstructures of different scales can form scattering at different angles, including small-angle X-ray scattering (SAXS, >1 nm) and wide-angle X-ray scattering (WAXS, <1 nm). X-ray scattering is an important experimental technique for studying nanometer-scale structures in materials. The sizes of microstructures such as polymer crystallization, microphase separation of block copolymers, nanofillers, and microvoids in fibers fall within this range.
Figure 2. Detection Scale Range of X-ray Small-Angle Scattering (SAXS)
Table 1. Structural Information Obtained from X-ray Small-Angle Scattering (SAXS)
| System | Information obtained from SAXS (WAXS) |
| Monodisperse Particle System | Particle size, particle morphology (spherical, rod-shaped, or plate-like), radial electron density distribution, and molecular weight |
| Polymer System | Correlation length, domain structure of crystalline and amorphous regions (orientation, size), and lattice structure |
| Liquid Crystal System | Long-period structures, long-range order, and lattice symmetry and size |
| Powder System | Average particle size, particle size distribution, specific surface area, etc. |
| Energy Range： | 5 ~ 15 keV |
| Energy Resolution： | 4.4 × 10-4 @ 10keV |
| Photon Flux： | 2 × 1011 phs/s @ 10keV |
| Beam Size： | 0.5(h) × 0.5(v) mm2 @ 10keV |
| SAXS Measurement Scale： | 1-80 nm (q range at 10keV : 0.078 ~6.28 nm-1) |
