Group Members  

   
Elisabeth Andreoli de Oliveira
   
andreoli@if.usp.br
Currículo Lattes

Professional address:

Instituto de Física-Universidade de São Paulo
Caixa Postal 66318- CEP 05315-970
São Paulo-SP-Brazil
Tel: 55-11- 30 91 6719
Fax: 55-11- 30 91 6771

Present position: Associate professor

Academic Degree

  • Bachelor in Physics, University of São Paulo, São Paulo, Brazil (1982)
  • MSc. in Physics, University of Campinas, Campinas, Brazil (1987)
  • Ph.D in Physics, University of São Paulo, São Paulo, Brazil (1991)

Professional Experience

  • Associate Professor at the University of São Paulo, 1999
  • Professor Doctor at the University of São Paulo, 1991
  • Assistant Professor at the University of São Paulo, 1990
  • Technic in Optics at the Institute of Space Research, (INPE), São José dos Campos, Brazil (1985-1987)

Research

    Liquid crystalline phases are present in materials composed of interacting molecules or aggregates of molecules that are naisotropic in shape. The moelcules tend to align parallel to each other and the average orientation is characterized by a unit vector, called the director. The particular orientation adopted by the moelcules can be fixed by external fields (electrical or magnetic) or by boundary conditions. My current interest are:
 
  • Interfacial interactions: We investigate the orientation induced to the nematic liquid crystal by a polymeric film containing azo–dye groups in the lateral chain. The aspects investigated are: temporal stability, the manipulation of the anchoring strength and effects of competition on textured substrates.
  • Anisotropic colloids: Dispersion of nanoparticles in a nematic liquid crystal leads to new composite materials with physical properties that reflect the orientational order of the medium. In particular, in lyotropic liquid crystals one can handle with situations where the dimension of the dispersed particles is comparable to the the nematogen unit, and in this case the director field will not be affected by foreign particles. We investigate an anisotropic colloid formed by the dispersion of nanoparticles in a nematic lyotropic liquid crystals using x-ray scattering, optical observations and rheological properties.
  • DNA encapsulation in lamellar phases: The use of synthetic systems to introduce DNA into the nucleus lies as the most promising approaches for gene therapy. Several systems based on cationic lipid-DNA complexes have been essayed; however their toxicity limits in vivo applications. Recently, it was demonstrated that it is possible to introduce DNA in a lamellar phase of non cationic and biocompatible lipids, due to a purely entropic process. We are interested in the structural and dynamical properties of DNA molecules intercalated  between lecithin bilayers. The techniques used in this study are X-ray scattering on oriented samples, and microscopy (polarization and fluorescence).

Publications

  • I.H. Bechtold, F. Batalioto, L.T. Thieghi, B.S.L. Honda, M. Pojar J. Schoenmaker, A.D. dos Santos, V. Zucolotto, D.T. Balogh, O.N. Oliveira Jr, and E.A. Oliveira, “Transitions in the orientational order of liquid crystals induced by periodic patterned substrates”, Phys. Rev. E 74, 021714 (2006).

  • L. T. Thieghi, F. Batalioto, I. H. Bechtold, V. Zucolotto, D. T. Balogh, O. N. Oliveira Jr. and E. A. Oliveira, “Phenomenological analysis of the ligth intensity dependence of the photoalignment process in azo-containing polymeric films”, Phys: Rev. E 74, 011802 (2006).

  • F. Batalioto, I. H. Bechtold, L. R. Evangelista, E. A. Oliveira, “Effect of microtextured substrates on the molecular orientation of a nematic liquid-crystal”, Phys. Rev. E 72, 031710 (2005).

  • I. H. Bechtold and E. A. Oliveira, “Liquid crystal alignment on anisotropic homeotropic planar patterned substrates”, Liquid Crystals, 32, 343(2005).

  • I. H. Bechtold and E. A. Oliveira, “Liquid crystal alignment on isotropic submicro-textured surfaces of homeotropic-planar state”, Mol. Cryst. Liq. Cryst. 32(3); 343-347(2005).

  • D. Walton, S. M. Shibli, M. L. Vega, E. A. Oliveira, “ Superparamagnetism and blocking in ferronematic liquid crystals”, J. Magnetism and Magnetic Materials 292, 310 (2005).

  • B. B. Postacchini, L. F.C. P. de Lima, Y. Kawano and E. A. Oliveira, “Effects of UV irradiation on optical birefrigence of a polyuretane elastomer”, Mol. Cryst. and Liq. Cryst 437, 1255-1267(2005).

  • I. H. Bechtold, S. L. Gómez, J. J.Bonvent, E. A. Oliveira, J. Hohlfed and Th. Rasing, “Surface induced orientational phase transition in a lyotropic liquid crystal by optical second harmonic generation” , Phys.Rev. E 69, 061707(2004).

  • L.T. Thieghi, R. Barberi, J. J. Bonvent, E. A. Oliveira, J. A. Giacometti and D. T. Balogh, “Manipulation of anchoring strength in an azo-dye side chain polymer by photoisomerization”, Phys. Rev. E 67, 041701(2003).

  • I. H. Bechtold, J. J. Bonvent, M. L. Vega and E. A. Oliveira, “Surface treatments for lyotropic liquid crystals alignment” , Mol. Cryst. Liq. Cryst. 391, 95(2003).

  • L. T. Thieghi, J. J. Bonvent, E. A. Oliveira, J. A. Giacometti and D. T. Balogh, “Competition between anchoring and reversible photo-induced alignment of a nematic liquid crystal" , Appl. Phys. A. 77, 911(2003).

  • I. H. Bechtold, M. P. de Santo, Th. Rasing, J. J. Bonvent and E. A. Oliveira, "Rubbing induced charge domains observed by electrostatic force microscopy-effects on the liquid crystals alignment" , Liq. Cryst. 30(5), 591-598(2003)

  • I. H. Bechtold, J. J. Bonvent and E. A. Oliveira, “Dynamical behavior of a nematic lyotropic liquid crystal in planar confined geometries”, Phys. Rev. E 65, 011704(2002).

  • R. Farhi, A. Andreau, E. A. Oliveira, J.-P. Marcerou, H. T. Nguyen, J.-M.Tascon, “Raman Scattering from liquid crystal”, Mol. Cryst. Liq. Cryst. 365, [1831]/875(2001).

  • M. B. Lacerda Santos, E. A. Oliveira and A. M. Figueiredo Neto, "Rayleigh scattering of a new lyotropic nematic liquid crystals system: crossover of propagative and diffusive behaviour",  Liq. Cryst 27, 1485(2000).

  • J. J. Bonvent, I. H. Bechtold, M. L. Vega and E. A. Oliveira, “Alignment and phase transition induced by surface action in lyotropic nematic liquid crystals”, Phys. Rev. E 62,  3775(2000).

  • A. L. Alexe-Ionescu, L. M. Vega, J. J. Bonvent, E. A. Oliveira, “Surface breaking in lyotropic nematic liquid crystals induced by a magnetic field”, Phys. Rev. E 60, 6847(1999).

  • V. L. Lorman, E. A. Oliveira, B. Metout, “Orientational transitions in lyotropic liquid crystals; “twist-and-glide”states, Physica B 262, 55(1999).

  • L. M. Vega, J. J. Bonvent, G. Barbero and E. A. Oliveira, ”Critical orientational states of a lyotropic liquid crystal induced by a magnetic field”, Phys. Rev.E 57,  R3715 (1998).

  • E.A. Oliveira, “Surface effects on lyotropic liquid crystals”, Braz. J. Phys. 28, 339(1998).

  • B. Mettout, P. Toledano, H. Vasseur, E. A. Oliveira and A. M. Figueiredo Neto, “Theory of the lamellar-hexagonal transformation: tilted mesophases in lyotropic systems”, Phys. Rev. E.56, 6829 (1997).

  • V. L. Lorman, E. A. Oliveira and B. Mettout, “Theory of gliding-anchoring phase transition in a lyotropic liquid crystal”, Phys. Lett. A 231, 283(1997).

  • E. A Oliveira, G. Barbero and A. M. Figueiredo Neto, “Metastable periodic Freedericksz transition in nematic liquid crystals”, Phys. Rev. E 54, 5830(1996).

  • E. A. Oliveira, G. Barbero, A. M. Figueiredo Neto and A. K. Zvezdin, “Dry friction and critical state in lyotropic nematic liquid crystals submitted to a magnetic field”, Phys. Lett. A 222, 113(1996).

  • R. F. Turchiello and E. A. Oliveira, "Behavior of the director reorientation in glass surfaces of lyotropic liquid crystals in the nematic to biaxial transition", Phys. Rev. E 54, 1618(1996).

  • A. M. Ribas, L. R. Evangelista, A.J. Palangana and E.A. Oliveira, “Anchoring strength of a lyotropic nematic liquid crystal”, Phys. Rev. E 51, R5204, (1995).

  • E. A. Oliveira and A.M. Figueiredo Neto, "Anchoring Properties of liotropic liquid crystal near the nematic-isotropic transition", Phys. Rev. E 49, 629(1994).

  • E. A. Oliveira, P.J. Photinos and A.M. Figueiredo Neto, "Anchoring properties of lyotropic nematic discotic CsPFO/water mixture", Liq. Crystals 14, 837 (1993).

  • E. A. Oliveira,  A. M. Figueiredo Neto and G. Durand, "Gliding anchoring of lyotropic nematic liquid crystals on amorphous glass surfaces" Phys. Rev. A., 44, R825 (1991).

  • E. A. Oliveira and A.M. Figueiredo Neto, "Surface Treatment with ferrofluid for liquid crystal alignment", Magnitnaya Gidrodinamika, 4, 25 (1990).

  • E. A. Oliveira, L. Liebert and A.M. Figueiredo Neto, "A new soap/detergente/water lyotropic liquid crystal with a biaxial nematic phase", Liquid Crystal, 5, 1669 (1989).

  • E. A. Oliveira and  Jaime Frejlich,  "Thickness  and refractive index dispersion measurement using the Haidinger interferometer", Appl. Op., 28, 1328 (1989).

Member of Brazilian Society of Physics (SBF)