Electronic Energy Transfer in New Polymer Nanocomposite Assemblies
ROCHESTER UNIV NY DEPT OF CHEMICAL ENGINEERING
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New light-harvesting thin film supramolecular assemblies, consisting of rod-coil polymer nanocomposites as the light-absorbing energy donors and a randomly dispersed conjugated rigid-rod polymer as the energy acceptor, have been prepared and shown to exhibit efficiency for singlet electronic energy transfer as high as 93. The film thickness dependence of energy-transfer efficiency allowed us to determine the contributions of Forster and radiative mechanisms to energy transfer in the polymer nanocomposite assemblies. The Forster energy transfer efficiency was found to increase with increasing acceptor concentration, reaching an asymptotic maximum of 48 at approx. 3. On the other hand, radiative transfer diminished to an insignificant contribution at low acceptor concentration 1 mol. The Forster energy transfer efficiency varied significantly with the length of the flexible coil segment which regulates the supramolecular structure of the photoactive nanocomposite energy donor. The average intersite distance between donor and acceptor chromophores was measured spectroscopically to be in the range of 10 to 25 A with corresponding Forster radii of 19-23 A in the three series of supramolecular donoracceptor assemblies investigated, depending on the acceptor concentration. The present results on novel light-harvesting polymer nanocomposite assemblies represent the successful supramolecular regulation of efficient electronic energy transfer in thin films and hence are promising for exploring optoelectronic applications. Polymer nanocomposites, Electronic energy transfer, Light-harvesting assemblies, Supramolecular regulation, Conjugated polymers.
- Polymer Chemistry
- Laminates and Composite Materials
- Atomic and Molecular Physics and Spectroscopy
- Solid State Physics