L.A.S.A. Prado

Reduction of methanol permeability in polyetherketone–heteropolyacid membranes

Organic–inorganic membranes for direct methanol fuel cell (DMFC) application were prepared, using an organic matrix of sulfonated polyetherketone (s-PEK), different heteropolyacids and an inorganic network of ZrO2 or RSiO3/2. The membranes were characterized concerning their methanol and water permeability by pervaporation and ionic conductivity by impedance spectrometry. The bleeding out of the heteropolyacid from the membrane was quantified. The presence of the ZrO2 decreases the methanol and water permeability and reduces the bleeding out of the heteropolyacid. Molybdophosphoric acid (MoPA) was also investigated, showing a more pronounced bleeding out effect, which could be reduced by modifying the anion structure with the inclusion of Ni or Si. High conductivity values were obtained with membranes containing tungstophosphoric acid (TPA).

Materiais híbridos orgânico-inorgânicos: preparação e algumas aplicações

The preparation and application of organic-inorganic hybrid materials are under fast development and constitute an interesting research topic on account of the versatility and wide range of applications offered by these materials. These properties can be achieved due to the mixture of the components at the molecular level. The present review covers the state of the art, the most useful preparation routes and the potential applications of these materials.