Nanoparticles
and Colloids

SAXS for Nanoparticles and Colloids

Nanoparticles derive their remarkable properties from structures that emerge at the nanometric scale. Their size, surface-to-volume ratio, internal architecture, and the way they are dispersed or assembled fundamentally dictate material properties. Even subtle changes at this lengthscale can shift performance dramatically. As materials evolve toward increasingly sophisticated architectures such as core–shell particles, hybrid nanostructures, and anisotropic colloids, precise control of nanoscale organization becomes essential for achieving reliable, tunable functionality.

Yet measuring these parameters across large particle populations, under native conditions and over relevant timescales, remains a significant challenge. This is where Small-Angle X-ray Scattering (SAXS) provides decisive value. SAXS delivers statistically robust, ensemble-averaged information on size distributions, shapes, internal contrasts, and interparticle correlations in solutions, powders, or solid matrices, without drying, staining, or disruptive sample preparation. Modern modeling approaches enable extraction of polydispersity, core–shell parameters, aggregate structure, and structure factors that capture colloidal interactions. Time-resolved SAXS and USAXS further extend this capability to growth, self-assembly, and aggregation kinetics, revealing nucleation, sintering, or destabilization pathways under realistic temperature, solvent, or ionic conditions. In practice, SAXS offers a quantitative foundation for optimizing nanoparticle synthesis, stabilizing formulations, and linking nanoscale organization directly to macroscopic performance.