In situ synthesis of photoluminescent films of PVC, doped with Ce3+ ion

In this paper we report on the in situ synthesis of photo luminescent and patterned polyvinyl chloride (PVC) films, doped with cerium chloride. The precursor of the doping agent is the Tris(2-4 pentanedionate)cerium(III)center dot 3H(2)O, Ce(acac)(3), which absorbs UV and visible light. The PVC is both the photochemical source of chloride ion and the rigid matrix where: the CeCl3 luminescent particles are dispersed. The PVC films containing cerium complex in the concentration range 0-3% w/w did not exhibit luminescence over 320 nm. After irradiation at 254 nm, the films of pure PVC exhibited luminescence emission with a maximum at about 420 nm, by excitation at 300 nm, due to the presence of polyenes, likely formed by PVC photodehydrochlorination. In PVC films, containing cerium complex, the HCl photoproduct underwent substitution of acac-, with the formation of CeCl3 and Hacac, detected by XPS and FTIR, respectively. Thus, these films exhibited the luminescence emissions of the cerium chloride at about 360 nm and that of the polyenes at 420 nm, that was evidenced well by excitation at 260 and 300 nm, respectively. The film luminescence appeared after an induction period which was a function of the Ce(acac)(3) percentage and which was different for the two emitting species, as resulted by deconvolution of the luminescence band. The film irradiation by using a mask resulted in direct photopatterning. The luminescence emission occurred exclusively from directly irradiated zones. Thus no reaction occurred for the migration of reactive species. The FTIR analysis of the films, before and after sufficient irradiation to obtain luminescence, did not evidence significant changes in the chemical structure of the polymer and in the surface properties. Thus, this method can be used to provide PVC with luminescence without damaging side effect. (C) 2007 Elsevier B.V. All rights reserved.