Nanocomposites with lanthanide’s ions: Structure- properties relationships (LANANOCOMP)
Summary of the Proposal: Nanocomposites (or hybrid organic-inorganic materials) with lanthanides (Ln³⁺) represent a hot topics research worldwide as they offer the possibility of fine tuning the optical response by controlling Ln³⁺ - host interactions at a nanometric scale. While the coordination chemistry of lanthanide’s ions is well-known and several synthesis methods of lanthanides-nanocomposites are currently developed, many of the problems remained unsolved are related to the basic mechanisms of luminescence. The broad objective of the project is to investigate structure - photophysics relationships in Ln³⁺-nanocomposites. A great variety of structural investigation methods are considered: (FT-IR, XRD, NMR, ESR, XPS, luminescence spectroscopy). The study of the optical properties is based on a comprehensive spectroscopic instrumentation and methods such as optical absorption, excitation spectroscopy, steady-state and time-resolved laser induced luminescence spectroscopy with temporal resolution from ps to ns. The expected results concern (1) synthesis of novel nanocomposites with Ln3+ with emission spanning a broad spectral domain, from UV/VIS to NIR and lifetimes varying form several µs to ms and and (2) in-depth investigation and modeling of the excited state dynamics of Ln³⁺ in nanocomposites as well as the confinement effects induced by the nanocomposites structure on the luminescence properties. Applications to photonics, but also to sensing and environment are addressed.

Project leader - NILPRP (Carmen Tiseanu)
Partner 1 - UNIBUC (University of Bucharest, Prof. V.I. Parvulescu)
Partner 2 - UBB (University of Babes-Bolyai, Prof. S. Simon)
Partner 3 - NIMP (National Institute of Materials Physics, Dr. A.Manea)

Stage 1. (2006-2007) Structure- properties relationships in nanocomposites with UV/VIS emission prepared with sol-gel and hydrothermal methods.

Publications

1. C. Tiseanu, B. Gagea, V. I. Parvulescu, V. Lorenz-Fonfria, A. Geßner and M. Uwe Kumke, "Investigation of the hydrophobization efficiency of terbium-exchanged BEA zeolites by means of FT-IR, TGA, physical adsorption and time-resolved photoluminescence", Langmuir 23(2007) 6781.

2. C. Tiseanu, V. I. Parvulescu, V. Lorenz-Fonfria, A. Geßner and M. U. Kumke, "Comparative photoluminescence properties of silylated terbium-exchanged USY, MOR and ZSM-5 zeolites", submitted.

3. C. Tiseanu, A. Geßner, M. U. Kumke and V. Parvulescu, "Dehydration and rehydration effects on the photoluminescence properties of terbium-exchanged MFI type materials", submitted

4. C. Tiseanu, A. Geßner, M. Kumke, B. Gagea, V. Parvulescu, J. Martens, "Luminescence spectra and dynamics of lanthanides doped microporous- mesoporous materials", submitted.

5. C. Tiseanu, V. Lorenz- Fonfria, A. Geßner, M. Kumke, "Comparative study of terbium-exchanged zeolites functionalized with alkoxysilanes", submitted.

6. C. Tiseanu, A. Geßner, M. Kumke, " Effects of the Si to Al ratio and silylation on the photoluminescence studies on europium – exchanged microporous-mesoporous materials", in preparation.

Conferences

1. C. Tiseanu, A. Geßner, M. Kumke, B. Gagea and V. Parvulescu, "Luminescence spectra and dynamics of lanthanides doped microporous- mesoporous materials", abstract accepted for the 16th International Conference on Dynamical Processes in Excited States of Solids, Segovia (Spain) June, 17-22, 2007.

2. C. Tiseanu, A. Geßner, M. Kumke, V.Parvulescu, "Effects of the Si/Al ratio on the photoluminescence properties of lanthanide's- exchanged microporous- mesoporous materials", abstract accepted for the XIV International Sol-Gel Conference, Montpellier, France, 2-7 September 2007

3. C. Tiseanu, V. Lorenz- Fonfria, A. Geßner and M. U. Kumke, "Comparative study of terbium-exchanged zeolites functionalized with alkoxysilanes", abstract accepted for the International Conference on Optical, Optoelectronic and Photonic Materials and Applications, London, England, 30 July-03 August 2007

4. A. Geßner, M. U. Kumke and C. Tiseanu, "Luminescence properties of lanthanide’s doped MFI-type materials", the Bunsen Conference, Graz, Austria, 17-19 May, 2007