Field of Expertise: Advanced Material Science

Dye functionalized Polymer architectures
Manuel Hollauf(a), Merima Cajlakovic(b), Stefan Köstler(b), Paul Hartmann(b), Gregor Trimmel(a)
15:00 - 17:00 Thursday 23 October 2014 Rechbauerstrasse 12, HSII

Incoherent up-conversion of Photons by sensitized Triplet-Triplet-Annihilation (TTA) of emitter molecules is a relatively efficient process to transfer electromagnetic radiation of low energy into higher energies (e.g., near-infrared to visible radiation). In a first step a sensitizer molecule is excited (e.g., by sunlight) into its singlet state that quickly relaxes into a metastable triplet state by intersystem crossing. In presence of suitable emitter molecules that have triplet levels of similar energy a Triplet-Triplet-Energy-Transfer from the sensitizer to the emitter takes place, followed by TTA of two adjacent emitter triplets and radiative emission of a photon of higher energy compared to the absorbed ones. Thus, for efficient TTA-processes in a polymeric material, two suitable dye molecules have to be incorporated in suitable concentrations and with optimum distances between both. This can be easily achieved by controlled co-polymerization of dye-functionalized monomers with matrix monomers. We focus in this contribution of the preparation of new dye functionalized monomers based on norbornene as basic monomeric unit. Using ring opening metathesis polymerization (ROMP), designed statistical as well as block copolymers can be prepared.
In the first stage of this project we focus on the preparation of the dye functionalizes monomers using naphthalimide and perylene derivatives. The dyes had been chemical modified so that the molecules have an easily accessible amino or hydroxy group to prepare the corresponding norbornene amide or ester. Due to the poor solubility of the perylene compound it was necessary to modify it with 2,5-di-tert-butylaniline to counter the π-π stacking interaction.
First optical characterization – absorption and photoluminescence spectroscopy – will be presented, showing that the monomers as well as the polymers have similar optical properties than the original non-substituted dyes. First result on the preparation of defined co-polymers will also be presented.
This project "PoTTA" is funded by the Austrian "Klima und Energiefonds" within the program Energy Emission Austria.