IR ns pulsed laser irradiation of Polydimethylsiloxane in vacuum. (July 2020) - Torrisi, L.
Abstract: Polydimethylsiloxane (PDMS) has been irradiated by a ns pulsed IR laser in vacuum and the radiation effects induced by the coherent radiation, above a threshold fluence, produce a non-equilibrium plasma and material ablation. The laser absorption can be enhanced using gold nanoparticles (AuNPs) embedded in the polymer. The laser-generated plasma has been characterized, whereas the ion emission from both the virgin PDMS and the PDMS + AuNPs sheets has been analysed both in mass and energy. Morphological investigations, optical spectroscopy and compositional analyses have been performed. The adopted laser treatment can be employed to modify the properties of PDMS with and without AuNPs inducing a local enrichment of microcrystalline silicon in both cases. Highlights: Virgin PDMS is very transparent to near IR lasers. PDMS with Au NPs is very absorbent IR lasers. Ns pulsed laser at 10 10 W/cm2 produce a plasma at about 22 eV temperature. The irradiated PDMS shows formation of crystalline Si and SiC structures. The PDMS transparence reduces increasing the number of laser irradiation shots.