Membranes, Chemical and Electrochemical Processes Group

Group Leader: Vítor Geraldes

The Group develops its activities in the research areas:

Preparation, functionalization and characterization of polymeric membranes

  • Synthesis of polymeric membranes, based on new nanostructured functional materials, having in mind practical applications in the fields of water, environment,  chemical processes, medical devices, food and biorefineries.
  • Characterization of Polymeric Membranes by ATR-FTIR, SEM, TEM, XPS and AFM.
  • Development of bio and hemocompatible bi-soft segment Polyurea/polyurethane (PU) membranes, for blood oxygenation.
  • Development of polymeric, mixed matrix or nanocomposite membranes, by tailoring membrane design, morphology and characteristics on a molecular level to control mass transport in the different applications.

Design of membrane module devices and modeling of Flow and Mass Transfer at Membrane /Fluid Interfaces

  • Artificial Organs. Artificial Organs are associated to clinically well-established membrane-based treatments and assure, in extracorporeal blood circulation devices, the metabolic functions of a failing organ such as the hemodialyzer (HD)and the membrane blood oxygenator (MBO) for the substitution of the kidney and the lung, respectively. Technical and medical progresso is achieved through: 1) hemocompatibility of the membrane/blood interfaces with monophasic asymmetric hybrid cellulose acetate/silica membranes for HDs and bi-soft segment polyurethane asymmetric membranes  for MBOs 2) enhancement of the flow management/mass transfer associated to the metabolic functions of the artificial kidney/lung  in custom-made benchmark devices with a membrane surface area of 60 cm2 as surrogate systems of the artificial kidney and artificial lung to  accomplish in blood compatible environment, stable and long-term blood purification and oxygenation, respectively
  • Modelling of Flow and Mass Transfer in Membrane modules, medical devices and Micro Fluid Systems. Recourse to Computer Fluid Dynamics (CFD) to simulate and optimize mass transfer in Ultrafiltration (UF)/Nanofiltration (NF)/Reverse Osmosis (RO) plate-and-frame and spiral wound modules. Model validation with Micro-PIV (“Particle Image Velocimetry”) and holographic interferometry.
  • Flow and mass transfer analysis and module design for artificial organs involving extracorporeal blood circulation. modelling of membrane processes with recourse to CFD incorporating quantitative parameters pertaining to membrane characteristics, flow structures and mass transfer mechanisms.
  • Optimization of mass transfer and flow structure in membrane medical systems incorporating new hemocompatible membranes (blood oxygenators, immunoisolation) and membrane modules.
  • Development of UF medical devices for water removal in extracorporeal blood systems.
  • Development of new centrifugal nanofiltration devices for concentration and purification of small volume samples.

Development of Membrane Hybrid Processes and Membrane Reactors

  • Design, modelling, simulation of membrane-based processes for water, environment, chemical processes, food, wine and biorefineries.
  • Fractionation/Purification of valuable products from processing wastewaters of cork (tannins), pulp and paper (lignosulfonates, hemicellulose ,lignin) ,wine (polysaccharides ,       polyphenols ) and cheese whey (proteins, oligosaccharides) by Membrane Processes.
  • Electrodialysis in wine industry: development of a more efficient Electrodialysis  process for tartaric stabilization of wines.
  • Application of membrane technology in the fractionation / purification of bioactive compounds from renewable sources.

Electrochemical materials and processes for energy and environmental applications

  • Development of novel materials and technologies for application to environmentally friendly energy conversion and storage processes with industrial significance.
  • Development of materials for low temperature fuel cells, namely metal-based nanosized catalysts for borohydride electrooxidation, three dimensional cathodes for O2/H2O2 reduction, small-scale direct borohydride fuel cells, and alcohol-fuelled proton exchange membrane fuel cells.
  • Development of materials for water electrolysis, namely, functional cathodes for H2 production, and development of novel alkaline electrolysers.
  • Waste-to-energy electrochemistry, namely by electrolysis of industrial, domestic and swine breeding wastewater, to decrease the organic load and the treatment costs. Electrolysis of pulp mills by-products in order to optimise and improving the industrial Kraft process.
  • Environmental oriented electrochemistry, namely mediated electrochemical oxidation of pollutants and carbon dioxide mitigation.