Excimer lasers for surface engineering of polymer-based composites

Polymer-based composites being composed of a polymer in which specific additives are imbedded, derive most of their physical properties from such additives. In this presentation, it is shown how some of the properties of such plastics may be effected by excimer laser irradiation via processing the imbedded additives without altering the polymeric base. Attention is here restricted to the colouring of specific plastic composites which is shown to result from the laser-induced physico-chemical transformation of incorporated inorganic compounds as additives. In particular, phase transition and oxyde reduction are demonstrated for the TiO ₂ additive as a function of the laser energy density upon (248 nm) single pulse irradiation.