In Situ Grazing Transmission Small Angle X-Ray Scattering Study of Supramolecular Nanocomposites

Thin film assembly of nanoparticles in block copolymer-based supramolecules provide a versatile platform to generate hierarchically structured materials with varying compositions, structures and properties. In order to select and tune these films, the pathway of assembly must be understood. Using in situ X-ray scattering studies, the formation of structure can be monitored. Here, in situ grazing transmission small angle X-ray scattering (GTSAXS) was used to investigate the drying process of supramolecular nanocomposites. Data collected via GTSAXS does not contain complex correlations nor is it distorted by refraction and reflection the way grazing incident small angle X-ray scattering (GISAXS) is. It also gives information for small and negative q_z values, making it idea for use in in situ studies where changes in structure may be subtle. It was observed that highly ordered structures form quickly after casting. As the drying process continues, the order degrades somewhat and the structure becomes anisotropic. These in situ studies provide insight into how order is formed in supramolecular nanocomposites.