Roberto Di Paolo



Departamento de Engenharia Química e Biológica (DEQB)
Instituto Superior Técnico
Universidade Técnica de Lisboa
Av. Rovisco Pais  - 1049-001

phone: (+351) 21 8419606
Scientific Activity

Recent Publications
Since the beginning of my scientific career, the different research projects in which I have had opportunity to participate allowed me to acquire a broad experience with a large variety of optical techniques that I had to deal with, particularly laser induced fluorescence.

The collaboration with several research groups gave me an invaluable experience in interdisciplinary areas, including chemical physics, biophysics, photonics, always with the use of spectroscopy techniques as common denominator.

Currently, I am studying energy transfer mechanisms and conformational relaxation processes in conjugated polymers, and new luminescent metal complexes and their composites with conjugated polymers, for potential application in light emitter diodes (LED). In order to provide deeper insight into the relaxation along the polymer chain, different oligomers are been used as model compounds.

The structural relaxation of these compounds is studied by picosecond time-resolved fluorescence techniques in solvents of differing viscosity. The multiexponential fluorescence decays observed in both films and solution contain information on the processes resulting from excitation. The incorporation of metal complexes containing species that convert a high fraction of the input electric charge to emitted light, might be used to reach an important improvement in the performance of LEDs. Therefore, new luminescent metal complexes including the use of conjugated polymer hosts are being examined in order to evaluate potential applications of these materials in photonic devices.

Domain of specializations

Optical Spectroscopy of Materials.

Present research interests
  • Photophysical and photochemical characterisation of new materials for application in light-emitting devices.
  • Optical properties of polymers in solution and thin films.
  • Excited-state relaxation dynamics of oligomers studied by time-resolved fluorescence.
Other research interests
  • Determination of kinetic and spectroscopic parameters of photoisomerizable dyes, by using laser absorption spectroscopy and laser induced fluorescence.
  • Study of rotational diffusion by depolarization of fluorescence, for the determination of molecular structures in solution.
  • Determination of the optical properties of crystals doped with rare earth ions. Photoacoustic and luminescence techniques are used to obtain luminescence quantum efficiencies.
  • Design of optical gases emission sensors for use in industrial stack.
  • Fabrication and characterization of active waveguides in Lithium Niobate, doped with rare earth ions.
  • Second harmonic generation by quasi-phase matching in Zn-diffused periodically poled LiNbO3 (PPLN) channel waveguides.
  • Raman spectroscopy applied to the study of heme proteins.
  • Surface enhanced Raman spectroscopy by adsorption of molecules on metal surfaces.
Resonance Raman fingerprinting of multiheme cytochromes from the cytochrome c3 family
Roberto E. Di Paolo, Patrícia M. Pereira, Inês Gomes, Filipa M.A. Valente, Inês A.C. Pereira, and Ricardo Franco. J. Biol. Inorg. Chem., 2006 11: 217-224.

On-centered growth of periodically poled LiNbO3:Er3+:Yb3+ crystals
Eugenio Cantelar, Juan Antonio Sanz-García, Roberto Emir Di Paolo, Juan Enrique Muñoz-Santiuste, Fernando Cussó. Ferroelectrics, 334: 125-134, 2006.

Spectroelectrochemistry of type II cytochrome c3 on a glycosylated self-assembled monolayer
Inês Gomes, Roberto E. Di Paolo, Patrícia M. Pereira, Inês A.C. Pereira, Lígia M. Saraiva, Soledad Penadés, and Ricardo Franco. Langmuir, 2006, 22 (24), 9809-9811.

Electronic Spectral and Photophysical Properties of Some p-phenylenevinylene Oligomers in Solution and Thin Films
J. Seixas de Melo, J. Pina, H. D. Burrows, R. E. Di Paolo, and A. L. Maçanita Chemical Physics, 330 (2006) 449-456.

Conformational Relaxation of p-Phenylenevinylene (PV) Trimers in Solution, studied by Picosecond Time-Resolved Fluorescence
R. E. Di Paolo, J. Seixas de Melo, J. Pina, H. D. Burrows, J. Morgado and A. L. Maçanita Chem.Phys.Chem. 2007, 8, 2657-2664.

Modulating the Emission Intensity of Poly-(9,9-bis(6'-N,N,N-trimethylammonium)hexyl)-fluorenephenylene) bromide through interaction with Sodium Alkylsulfonate surfactants” M. Monteserín, H. D. Burrows, A. J. M. Valente, V. M. M. Lobo, R. Mallavia, M. J. Tapia, I. X. García-Zubiri, R. E. Di Paolo, A. L. Maçanita, J. Phys. Chem. B, 111 (48), 13560 -13569, 2007.