Characterization of Engineered nanomaterials by Spectroscopic Ellipsometry

For many emerging applications, nanocrystals are surface functionalized with polymers to control self-assembly, prevent aggregation, and promote incorporation into polymer matrices and biological systems. The hydrodynamic diameter of these nanoparticle–polymer complexes is a critical factor for many applications, and predicting this size is complicated by the fact that the structure of many grafted polymers at the nanocrystalline interface is not generally established.

One parameter that helps to elucidate the surface structure is the polymer film thickness. In this study Polystyrene on CdSe nanocrystals has been evaluated by Spectroscopic Ellipsometry, a non-destructive optical technique dedicated to the characterization of thin film structures. Spectroscopic Ellipsometry will routinely determine film thickness, optical constants (n, k), information on layer inhomogeneity and material structure.