Blend membranes based on sulfonated polyetheretherketone (SPEEK) and containing 5 wt.% of silylated and sulfonated polyphenylsulfone (SiSPPSU) were prepared and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR) and by electrochemical impedance spectroscopy (EIS). Tests in a direct methanol fuel cell station were also performed. The experimental results demonstrated that the presence of hybrid polymer SiSPPSU allowed to increase the proton conductivity of electrolyte and to improve its performance under fuel cell operating conditions. Due to its satisfactory properties, SPEEK/ SiSPPSU blend membrane has a potential use in DMFCs operating at intermediate temperatures.

A general, efficient and experimentally simple method for the synthesis of covalently crosslinked class II hybrid polymers based on PolyEtherEtherKetone (PEEK) with a high degree of sulfonation (DS = 0.8) was performed. The synthetic strategy foreseen two steps: the first one, direct sulfonation, led to the introduction of sulfonic acid groups and to the formation of sulfone bridges among repeat units. The second step, lithiation and silylation, led to the formation of covalent bonds between the organic backbone and Si(OH)3 moieties. The materials were characterized by 1H NMR Spectroscopy, ATR/FTIR Spectroscopy, Thermogravimetric Analysis (TGA) and Mass Spectrometry. Preliminary proton conduction measurements in dry conditions were performed. The introduction of silicon groups in the system improved thermal stability.

Sulfonated poly ether ether ketone (SPEEK) with a high degree of sulfonation (DS = 0.9) was mixed with a modified silane bearing a sulfonic acid function (sulfonated diphenylsilanediole, SDPDO).

Homogeneous composite membranes with several SPEEK:SDPDO ratios, were obtained. The addition of the ormosil significantly improved the water uptake and solubility properties of pure SPEEK.

The structural and electrochemical characteristics of the composite membranes were investigated by means of thermogravimetric analysis (TG), field emission scanning electron microscopy (FE-SEM), and electrochemical impedance spectroscopy (EIS). The conductivity values of the composites SPEEK/SDPDO demonstrated that they possess good proton transport characteristics, thus being suitable for application in Polymer Electrolyte Fuel Cells operating at intermediate temperature.

Commercial polyether-etherketone was sulfonated and reacted with SiCl4 to obtain a hybrid polymer. Polymers having different inorganic content were characterized by 29Si NMR, ATR/FTIR spectroscopies and mass spectrometry (FAB-MS) demonstrating the formation of covalent bonds between the organic and inorganic components and the absence of dispersed inorganic silicon. The physicochemical properties of the hybrids were suitable for the preparation of membranes which showed sufficiently high conductivity values to make them promising candidates for application in PEMFCs.

New ionoconducting composite membranes to be used as an interface between the skin and the actual electrical instrumentation used to produce an electroencephalogram (EEG) have been developed. The gels are based on lithium salts and PMMA (polymethyl methacrylate) and have been doped with nanometric titanium oxide. The samples have been electrochemically characterized by means of impedance spectroscopy and their structure studied by ATR-FTIR and MAS NMR. Spectroscopic studies indicate interactions between the polymer and oxide dopant. The polymeric electrolytes allowed the registration of good electrophysiological cortical signals either spontaneous or stimulus-related.