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Zirconium phosphates (ZrP) were incorporated into Nafion® 117 membrane by impregnating method to obtain a reduced methanol permeation and improved proton conductivity for fuel cell application. The mechanical properties and water uptake of Nafion® membrane incorporated with zirconium phosphates nanoparticles was more improvement when compared to the commercial Nafion® 117, due to the presence of phosphoric acid within the nanoparticles. The effect of ZrP nano filler on the membrane structural morphology and thermal properties were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA) and Scanning Electron Microscopy (SEM). The improved ion conductivity and decreased methanol permeability on the nanocomposite membranes showed a great potential for fuel cell applications. The nanocomposite membrane with high tensile strength was obtained due to the well dispersed zirconium phosphates within the Nafion® matrix.

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Stable and high surface area zirconium oxide nanoparticles have been synthesised by means of the hydrothermal method. The Brunauer-Emmett-Teller results show that a high surface area of 543 m 2 /g was obtained in the hydrothermal process, having a high porosity in nanometre range. The hydrothermal method was applied at 120°C by using an autoclave with a Teflon liner at an ambient pressure for 48 h. High-resolution scanning electron microscopy shows the different morphologies of zirconia nanoparticles, which could be categorised as one-dimensional and zerodimensional, as they had a high crystallite orientation, which was also confirmed by the X-ray diffraction (XRD). The mixture of two types of cubic phases in one sample was obtained from XRD and confirmed by the zirconia nanostructure, showing the stable phase of fluorite, which has full cubic symmetry (Im-3m), and also an Arkelite zirconia nanostructure, showing the stable phase of fluorite, which has full cubic symmetry (Fm-3m). The XRD results also show the different structure orientations of face-centred cubic and body-centred cubic in one sample.

Membranes are widely used daily, such as for filtration in reverse osmosis, or in the form of electrolyte membrane fuel cells. Modified Nafion ® membranes were synthesised by impregnation and their mechanical properties were observed. The effect of the incorporation of a ZrO 2 -CNT nano-filler within Nafion ® membrane on the thermal stability and crystallinity was investigated by TGA and XRD. Tensile test results show the increases in the mechanical properties of Nafion ® 117 membranes impregnated with ZrO 2 -CNT when compared with that of commercial Nafion ® 117 membranes. The results also show that adding ZrO 2 -CNT in Nafion ® 117 membranes improves the water contact angle and water uptake, as it enhances water retention within the membrane. The SEM results indicated that ZrO 2 -CNT was well distributed in the Nafion ® 117 membrane pores through the impregnation method.

SbstractThe morphological and mechanical properties of Ziegler-Natta catalyzed isotactic polypropylenes as influenced by the molecular weight and tacticity was investigated. Polypropylene samples were injection moulded into standard disks with a HAAKE MiniJet II injection moulder at 190 °C and 200 bar for morphological and mechanical tests. The morphological and mechanical properties of specimens were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), microhardness (MH) and dynamic mechanical analysis (DMA). The samples exhibited a typical α-modification spherulite structure of isotactic polypropylenes crystallized from the melt. It was found that the most important factor affecting the structure and properties of these polymers is the isotacticity content. A clear molecular weight effect was also found for samples with low molecular weights. The microhardness and storage modulus values increased as crystallinity did. Accordingly, isotacticity degree is considered as the main parameter affecting the crystallinity of samples.

Zirconia nanoparticles were prepared by the precipitation and ageing methods. The precipitation method was performed by adding ammonium solution to the aqueous solution of zirconium chloride at room temperature. The ageing method was performed by leaving the precipitate formed in the mother liquor in the glass beaker for 48 hours at ambient temperatures. The nanoparticles from both methods were further sulphated and phosphated to increase their acid sites. The materials prepared were characterised by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Brunauer-EmmettTeller (BET), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) methods. The XRD results showed that the nanoparticles prepared by the precipitation method contained mixed phases of tetragonal and monoclinic phases, whereas the nanoparticles prepared by ageing method had only tetragonal phase. The TEM results showed that phosphated and sulphated zirconia nanoparticles obtained from the ageing method had a smaller particle size (10-12 nm) than the nanoparticles of approximately 25-30 nm prepared by precipitation only. The BET results showed that the ZrO 2 nanoparticles surface area increased from 32 to 72 m 2 /g when aged.

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