Université de Fribourg

Two-photon 3d optical data storage via aggregate switching of excimer-forming dyes

Lott, Joseph ; Ryan, Christopher ; Valle, Brent ; Johnson, Jack R. III ; Schiraldi, David A. ; Shan, Jie ; Singer, Kenneth D. ; Weder, Christoph

In: Advanced Materials, 2011, vol. 23, no. 21, p. 2425–2429

A novel optical data storage (ODS) system that relies on the optically-induced switching of the aggregation state and fluorescence of a two-photon absorption dye in a polymer matrix is reported. Well-defined, -3 × 3 × 6 μm large voxels are written with single focused laser pulses and read by confocal laser scanning microscopy.

Université de Fribourg

Luminescent mechanochromic sensors based on poly(vinylidene fluoride) and excimer-forming p-phenylene vinylene dyes

Lott, Joseph ; Weder, Christoph

In: Macromolecular Chemistry and Physics, 2009, vol. 211, no. 1, p. 28-34

Cyano-substituted excimer-forming oligo(phenylene vinylene) dyes (cyano-OPVs) with terminal alkyl tails of different length were blended with two fluorinated host polymers with similar chemical composition but differing crystallinity. These blends were used to fabricate luminogenic mechanochromic thin films, which change their emission color upon deformation. The alkyl tails affect the solubility...

Université de Fribourg

Influence of temperature on low-power upconversion in rubbery polymer blends

Singh-Rachford, Tanya N. ; Lott, Joseph ; Weder, Christoph ; Castellano, Felix N.

In: Journal of the American Chemical Society, 2009, vol. 131, no. 33, p. 12007–12014

The upconverting properties of a dye cocktail composed of palladium(II) octaethylporphyrin (PdOEP, triplet sensitizer) and 9,10-diphenylanthracene (DPA, triplet acceptor/annihilator) were investigated as a function of temperature in several low glass transition temperature (Tg) polymer hosts including an ethyleneoxide-epichlorohydrin copolymer (EO-EPI) and the polyurethanes...