Probing nanoscale structure and dynamics of soft matter by synchrotron X-ray scattering

In this talk, I shall try to give an overview of different possibilities offered by synchrotron X-ray scattering for the investigation of soft matter. Recently, small-angle X-ray scattering (SAXS) has received renewed importance as a powerful characterization technique for soft condensed matter and biological systems. This trend is sequel to a combination of factors, most notably developments in X-ray instrumentation at modern synchrotron sources and parallel advancements of data analysis methods. One of the interesting outcomes is that the threshold of detection in scattering experiments has significantly diminished thereby allowing highly quantitative studies of extremely dilute systems and also probing very early stage of kinetic processes. I shall try to illustrate these developments using a variety of examples starting from model hard-sphere colloids to highly self-assembled biomaterials. Underlying issues include structure and interactions in concentrated systems, dynamics of self-assembly processes and multiscale structure of hierarchically ordered systems. Quantitative scattering experiments elucidate not only the transient structures and their growth dynamics but also reveal the link between nanoscale thermodynamics and macroscopic properties.