Changes in physical properties and molecular structure of polystyrene nanospheres exposed with daily solar flux

The effects of physical properties and molecular structure of 200 nm polystyrene nanospheres (PSN) coated on silicon wafer exposed with daily solar flux were explored by field emission scanning electron microscope (FE-SEM) and attenuated total reflectance-Fourier transform infrared (ATR-FT-IR) spectrometer. It is revealed that the particles shape of PSN changed from spheric to eight-shaped after solar radiation. Reduction of the size as much as 29.5% after 5 minutes exposure was also observed in PSN particles. Changes in the molecular structure of the PSN particles after solar radiation were observed where some of the phenyl moieties of polystyrene broke down to facilitate carbon-carbon cross linkage bonds. These results demonstrated that the shrinkage of PSN particles is caused by the change of the molecular structure of polystyrene.