Speaker
Description
Small-angle neutron scattering (SANS) is a versatile technique for investigating structural features and spatial correlations in materials over length scales typically ranging from approximately 1 to 100 nm, with the accessible range depending on the instrument configuration. By probing variations in neutron scattering length density, SANS provides insight into nanoscale structures in a wide variety of systems, including nanoparticles, porous materials, polymers, colloidal dispersions and supramolecular assemblies.
This introductory lecture will outline the fundamental principles of SANS, from the origin of neutron scattering contrast to the interpretation of scattering curves in reciprocal space. Particular attention will be given to the structural information that can be extracted from experimental data, including particle size and shape distributions, internal morphology, pore dimensions, characteristic distances and the organisation of multicomponent systems. The sensitivity of SANS to different length scales and volume fractions will also be discussed, together with the advantages of isotopic contrast variation, particularly through hydrogen/deuterium substitution.
Beyond characterising individual structural units, SANS offers a powerful means of investigating interactions and collective behaviour in complex systems. The separation of the scattering intensity into form-factor and structure-factor contributions provides access to interparticle correlations, enabling the analysis of attractive and repulsive interactions, aggregation, and concentration-dependent structural organisation.
The lecture will demonstrate how SANS connects nanoscale structure with the physical properties and behaviour of soft and complex materials, highlighting both the possibilities and limitations of the technique.