Structural characterization of spray-dried microgranules by spin-echo small-angle neutron scattering

Spray-drying is a widely used industrial technique and has shown an immense potential in the fields of nanoscience and technology. This is due to its ability to synthesize microgranules consisting of correlated nanostructures using evaporation induced assembly through bottom-up approach. Although the nature of correlation among the constituent nanoparticles and their size distribution could earlier be obtained by conventional Small-angle Scattering (SAS) technique, a statistically averaged quantitative measure of the shell thickness and hollowness of the formed granules remained a challenge. In this work, we have used Spin-echo Small-angle Neutron Scattering (SESANS) technique to characterize spray-dried nanostructured microgranules having different hollowness. It is shown that this non-destructive technique provided precise quantification of the granular sizes and hollowness by utilizing polarization property of neutrons in real space directly.