SAXS Study of Silicon Nanocomposites

The structural and interfacial properties of the inclusion of silicon nanoparticles in two classes of polymeric binders (1) a soluble polymer, and (2) a polymerizing monomers were investigated using small angle x-ray (SAXs) technique. The soluble polymers were cellulose acetate butyrate (CAB), and commercial quality, low density polystyrene foam (PS). The polymerizing monomer binders were a commercial acrylic printing base (ACR), and refined linseed oil (LIN). Analysis of the obtained SAXs result using the Gunier scheme suggests that the dispersion of the powders in the different binders consisted of a broad distribution of size heterogeneities, one in which the cluster mass is not uniform but varies over a size distribution in the range 69 to 74nm. Further analysis using Porod’s law revealed that the ACR, CAB and PS based composite resulted in a surface fractal structure while the LIN based composite gave a characteristic mass fractal with the size of the basic particles ranging from 61nm to 74nm in agreement with the Gunier analysis, while the size of the aggregate clusters ranges from 338 to 370nm. Analysis of the deviation from porods law from the SAXs data reveals that the all of the binder formed a diffuse interface with the embedded silicon powder except the LIN based composite sample which exhibited a two-phase system with electron density inhomogeneity.