Laser-evoked coloration in polymers

We report that two colors of red and green have been produced on an initially transparent CPV/PVA samples through UV laser-induced photo-chemical reactions. This is believed the first observation of laser-induced multiple-colors in the given polymer matrix. It is believed that the colorants underwent photo-effected electron transfer with suitable electron donors from the polymers to change from colorless bipyridilium Bipm2+ to the colored Bipm+ species. The discovery may lead to new approaches to the development of laser-evoked multiple coloration in polymers.