| Abstract: | Polymer films displaying lustrous, iridescent colors were obtained by irradiation of poly(methyl methacrylate) films containing 1,4-benzoquinone with a medium pressure mercury lamp followed by solvent treatment. The colors were not produced by visible light-absorbing species in the polymer films because the color seen in reflection was complementary to that seen in transmission. It was found from optical and scanning electron microscopic studies of the polymer films that they have two characteristic optical structures; a great number of microcylindrical air bubbles oriented perpendicularly to the film surface and periodic lamellas with planes parallel to the film surface. The colors of the polymer films were thought to be produced by this periodic lamellar structure which would act as a three dimensional optical reflection grating. Continuous color change on tilting the sample could also be explained by the Bragg equation. |
