Inorganic particles composite membranes

Most of the reported inorganic fillers used to modify Nafion are composite where the inorganic particles (usually nanoparticles) are located in the membrane bulk. Most of them are prepared using the recast method, where the filler nanoparticles dispersed in a solvent are mixed with Nafion ionomer dispersion in the same solvent or a compatible one. The solution is cast on a Petri dish or a plane surface at high temperature to form the recast composite membrane. An alternative method adopted to prepare Nafion composites with silica [31, 32, 41, 95], functionalized silica [35], and zirconium and titanium phosphate [41], is the in situ sol-gel reaction method, schematized in Fig. 6.5. 

An emerging new group of lithium-ion separator comprises of inorganic composite membranes ( ceramic separators ) with their excellent wettability and exceptional thermal stability properties. Most of ceramic separators are porous mats made of ultrafine inorganic particles bonded using a small amount of binder. 

It was observed that the surface acidify of the fillers influences the bending and stretching vibrational frequencies of the water physically adsorbed on the filler surface [6, 14]. The conductivity of composite membranes and maximum power density of DMFCs at 145 °C appear to be related to the characteristics of the water adsorbed oti the filler particles [6,14]. Inorganic fillers characterized by acidic properties undergo a strong interaction with water and enhance the DMFC performance at high temperatures. The self-diffusimi coefficients of water and methanol have been determined over... 

Although it is said that the silica is added to the PBI structure, the reality is that, in most of the cases, the silica is modified or functionalized in order to improve their characteristics of the PBI composite membrane. The incorporation of inorganic nanofillers in the polymer matrix is often carried out by in situ sol-gel creation of the particles during membrane casting [12, 13]. This method avoids silica nanoparticles agglomeration and therefore enables higher inorganic contents [14]. 

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