Nano-embossed structure on polypropylene induced by low energy Ar ion beam irradiation

The surface morphology evolution of polypropylene (PP) irradiated with an Ar ion beam was explored using a hybrid ion beam system. PP formed the emboss-like nanostructure of ∼ 50 nm induced by the Ar ion beam treatment for shorter ion beam treatment times, while the emboss-like structure was transited into a 3-D long nanofiber-like nanostructure for longer treatment times. The Fourier transform infrared spectra revealed that the polymer chain cross-linking increased with increasing ion treatment time, while the Raman analysis showed that the conducting amorphous carbon increased on the surface of PP. The surface hardness and plane strain modulus of the PP decreased from 0.11 to 0.07 GPa and from 1.75 to 1.26 GPa, respectively, with respect to the Ar ion beam treatment time due to the surface nanostructures formed by the Ar ion beam.