13. Synchrotron Small-Angle X-Ray Scattering and Small-Angle Neutron Scattering Studies of Nanomaterials

Small-angle scattering is a very powerful technique to probe structures of materials. X-ray, neutron, and light scattering techniques present structural information of materials in a wide range from nanometer to micrometer scale. Chemists, physicists, and engineers have used these techniques to study structures of various systems from hard to soft materials. In this topic, we focus upon soft materials such as polymers, gels, colloids, etc. We present a review of their recent studies with small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS).

In a typical experimental setup, synchrotron SAXS and SANS are capable of probing structures of aggregates in the range of 1–100 nm. The use of ultra-small-angle scattering techniques such as ultra-small-angle X-ray scattering (USAXS) and ultra-small-angle neutron scattering (USANS) makes it possible to probe structures of aggregates with larger size on a micrometer scale. Here we review some structural studies on various soft materials, which form a hierarchical organization. Recent development of synchrotron radiation source and neutron facility allows us to obtain scattering data on various length scales. It is shown that combination of various scattering methods provides us with information on hierarchical structures of soft materials from a microscopic to macroscopic level. The structural analysis on each level is also presented in the text. Furthermore, contrast variation and contrast-matching SAXS and SANS methods are very effective for structural investigation of multicomponent nanomaterials, e.g., these methods are very useful to probe internal structures of complex systems such as polymer micelles, polymer–inorganic nanocomposite gels, and rubber-filler systems swollen in an organic solvent.