Small-angle x-ray scattering to analyze the morphological properties of nanoparticulated systems

Abstract

Small-angle X-ray scattering (SAXS) is a powerful technique that uses the scattering of a beam of X-rays to investigate the structure, morphology, and arrangement of submicron dimensions and particularly useful for studying systems at the nanometric scale. Herein, in this chapter book, we will examine the most representative features of several scattering intensity curves acquired from several nanoparticulated systems. We begin with the explanation of the most fundamental concepts behind the SAXS framework, to then introduce the principal features of a scattering pattern. Each section of this chapter is complemented with practical examples, many of which are simulations, while others come from real experimental data taken from real samples synthesized for this purpose in our labs. As an important part of this work, we present two models often used to fit SAXS curves acquired from granular nanoparticle samples, which are the fractal aggregate and the Beaucage models. In this last part of these sections, our goal is to explain how to obtain valuable structural information from systems consisting of either nanoparticles surrounded by liquids or solids. Finally, we present a complete description of the principal components needed to a SAXS instrument.