SURFACE MODIFICATION OF POLYMER FIBERS BY UV LASER IRRADIATION .14. NOVEL MODEL CONCEPTIONS AND SIMULATION USING CELLULAR-AUTOMATA

Under suited conditions the pulsed UV-excimerlaser irradiation of poly mers generates a submicron morphology onto polymer surfaces. This repo rt describes a possible mechanism leading to this UV-laser-induced sur face structuring. The structure generation is mainly based on a strong absorption of the laser light resulting in thermal loading and meltin g of the polymer surface. The frozen-in stress fields are assumed to b e the driving force for cooperative material transport with high drift velocities especially at the free molten interface. This irreversible phenomenon of a self-organizing-effect needs permanent energy input w hich is delivered by the absorbed light energy and the stored elastic energy. A computer model based on the principle of cellular automata i s used to illustrate the characteristics of this thermomechanically in duced structure generation.