Research

  • Crystallization
  • Crystallization refers to the formation of solid crystals from a solution. Crystals are grown in many shapes, which are dependent upon downstream processing or final product requirements.  Crystal shapes can include cubic, tetragonal, orthorhombic, hexagonal, monoclinic, triclinic, and trigonal. The crystallization process consists of two major events, nucleation and crystal growth. Depending upon the conditions, either nucleation or growth may be predominant over the other, and as a result, crystals with different sizes and shapes are obtained (control of crystal size and shape constitutes one of the main challenges in industrial manufacturing, such as for pharmaceuticals).
  • Nucleation
  • Nucleation is the step where the solute molecules dispersed in the solvent start to gather into clusters, on the nanometer scale (elevating solute concentration in a small region), that becomes stable under the current operating conditions. These stable clusters constitute the nuclei. However when the clusters are not stable, they redissolve.
  • Crystal Growth
  • The crystal growth is the subsequent growth of the nuclei that succeed in achieving the critical cluster size.
  • Diffusion processes in disordered materials
  • Diffusion is a time-dependent process, constituted by random motion of given entities and causing the statistical distribution of these entities to spread in space. Molecular diffusion, often called simply diffusion, is a net transport of molecules from a region of higher concentration to one of lower concentration by random molecular motion. The result of diffusion is a gradual mixing of material.
  • Ionic conductivity
  • Is a special case of diffusion, where ions move under a presence of an eletric field. Ionic conduction in solids has been a subject of interest as early as the beginning of the 19th century, and established by Michael Faraday in 1839.
  • Glass formation
  • The glassy or vitreous state of matter is typically formed by rapid cooling and solidification from the molten (or liquid) state. A way to assess glass formation is the glass-forming ability concept, or the easiness to vitrify a liquid on cooling.
  • Experimental techniques on materials production & characterization
  • We have the following equipments available for materials production & characterization (with Protec/PEI-UFBA partnership):
    • Shimadzu LabX XRD-6000 X-ray diffractometer;
    • Shimadzu EDX 720 Energy Dispersive X-Ray Fluorescence Spectrometer;
    • Mettler-Toledo XS205 Dual Range balance, with 0.01mg precision;
    • Shimadzu DSC 60 A - Differential Scanning Calorimeter - Heat Flux Type (up to 600°C);
    • Shimadzu DTG 60 H - Differential Thermal Analysis - Calorimeter Type (up to 1500°C);
    • Shimadzu GC 2010 Gas Chromatograph;
    • EDG 1800 Melting furnace (up to 1200°C).

Last update: January 22th 2014