Creation of Light Scattering Images in a Polymer Film by Quantum Amplified Isomerization

Abstract

The quantum amplified, photosensitized isomerization of a Dewar benzene reactant to a benzene product was used to create a visible image based on differential light scattering. The reactant and a UV triplet sensitizer were dispersed together as small particles in a solid, continuous matrix of gelatin, coated on a polyester film support. The refractive indexes of the particulate and continuous phases were initially approximately matched, leading to an essentially transparent appearance. After exposure to UV light (absorbed by the sensitizer), the change in refractive index resulting from the isomerization caused a significant mismatch in refractive index between the particles and the binder. In addition, the product partially crystallized. The outcome was an opaque texture in the coating. A pictorial image attributable to regions of high and low light scattering could be prepared by irradiation of the coating through a simple contact mask. The scattering texture forms spontaneously on irradiation, without ...