Grupo de Reologia
Prof. Dra. Maria Regina Alcantara
FONE/FAX: +55 011 3091-2054
Lyotropic Liquid Crystals,
Optical Microscopy under polarized light.
Nuclear Magnetic Resonance of organized systems, particularly deuterium, sodium and cesium NMR.
The rheological properties of lyotropic liquid crystals are often
by their mechanical history, which may result in a modification of the
microscopic structure of the material. Shear induced transitions were
in concentrated solutions at defined salt content, indicating that the
micellar size is affected by the flow. The anisotropic rheological
of lyomesophases has been studied in recent years by means of
and non-oscillating rheological techniques, especially using the
geometries. The rheological parameters have been used to understand the
spatial arrangement of the system constituent units and the way they
their order near the transition regions. Results published by our
indicated that these systems are
pseudoplastic and are characterized by
a complicated transient response, either rheopexic or thixotropic,
on whether the micelles are cylindrical or discotic, respectively.
Additionaly our group has also been interested by the
study of the rheology of magnetorheological fluids based on carbonyl iron powders .