Surface properties of polymers treated with F 2 laser

Selected polymers (polyethylene‐PE, polypropylene‐PP, polytetrafluoroethylene‐PTFE, polystyrene‐PS and polyethylenterephthalate‐PET) were irradiated with the linearly polarized light of a pulsed 157 nm F 2 laser. The irradiation results in degradation of polymers and ablation of polymer surfaces. Contact angle, measured by goniometry, was studied as a function of the number of laser pulses. The volume of the ablated polymer layer was determined by gravimetry. Changes in surface morphology and roughness were observed using atomic force microscopy. Surface chemistry of the samples was investigated by electrokinetic analysis and by XPS. While PET and PE exhibit small ablation, the ablation of PS and PTFE is more significant, and the most pronounced ablation is observed on PP. Contact angle of all polymers, with the only exception of PP, is a decreasing function of the number of laser pulses up to 2000 pulses. Laser irradiation leads to a refinement of the polymer surface morphology and a decrease of their surface roughness. Electrokinetic analysis and PS show changes in the surface chemistry of polymers after the laser treatment.