Polymer-dye complexes: supramolecular route toward functional optical materials

We demonstrate that the aggregation tendency of dye molecules in a host polymer can be significantly reduced by exploiting non-covalent interactions between the host polymer and guest dye molecules. Such interactions occur spontaneously with no need for chemical synthesis, and could thus be utilized to combine the ease of processing of traditional guest-host systems with the high dye concentrations achievable in covalently linked systems. We studied the aggregation properties of the common azo-dye Disperse Red 1 in polymer matrices with different functional groups. The dye aggregation tendency is substantially reduced in a polar polymer matrix and, most importantly, by forming a polyelectrolyte-dye complex, a dye monomer can be attached to approximately each polymer unit. This indicates that polymer-dye complexes provide a facile route for new type of optical materials, which could lead to applications in various fields of optics and photonics.