Laser induced molecular transfer using ablation of a triazeno-polymer

We report on the laser induced transfer of molecular dopants between thin polymer films. Pulsed UV laser radiation 355 nm. of moderate intensity, is directed through a transparent polymer film and absorbed by a photolabile triazeno-polymer TP. doped with pyrene at low concentration. The explosive photodecomposition of TP results in the transfer of intact pyrene molecules to a tightly contacted neat polymer film of either poly ethyl methacrylate. PEMA. or poly butyl methacrylate. PBMA.. Fluorometry of the receiving polymer surface indicated that the pyrene emission intensity grows as the laser pulse number increases but reduces with rising laser fluence. Surface examination suggests that most of the transferred dopant is implanted beneath the receiving polymer surface and the efficiency of this process is enhanced with lowering of its glass transition temperature Tg. A mechanism is discussed to explain the current experimental results. q1998 Elsevier Science B.V.