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A comparative environmental assessment of a novel additive manufacturing technique against the established conventional route for titanium manufacture.

Titanium dioxide is widely used in numerous industries and with the newly developed titanium manufacturing technic, referred to as the Near-net-shape Electrochemical Metallisation (NEM) Process, the rapid and precise production of titanium dioxide components is highly sought-after. This manuscript presents the rheological investigation and extrudability tests of titania inks, to 2 establish the improved production of titanium dioxide components via Direct Ink Writing. The extrudability tests indicated that despite an unfavourable increase in viscosity during the high shear rates (dilatancy peaks), the best-performing ink had a weight ratio of 1:0.8:0.1 TiO2:H2O:PEG, and the dilatancy peaks were smoothed out with the addition of 0.1 weight ratio of oleic acid to the ink, dramatically improving the quality of the product. To further improve the green bodies a new printing approach was also introduced, removing the necessity for specialised printing bed, by printing a removable support into the green body and allowing for drying without any cracks and warping.

Cu 2 ZnSnS 4 (CZTS) is a promising non-toxic and cheap absorber layer for the use in photovoltaic cells. In this work copper, zinc and tin xanthates were synthesised and deposited using a single-source spray coating technique to produce CZTS thin films, to investigate how the ratio of these precursors can alter the performance of the device. It was determined that using a tin rich xanthate precursor mix resulted in the thin film with the chemical composition closest to CZTS, with few contaminating phases (i.e. Cu 2-x S, Cu 2 SnS 3 and ZnS). To explain this observation, isothermal thermal gravimetric analysis was used to determine rate constants for the decomposition of these xanthate precursors. The rate constants of copper xanthate and zinc xanthate align very well (1.26 and 1.24 s -1 respectively). However, the rate constant for tin xanthate differs significantly (1.09 s -1 ). Therefore, to form the appropriate ratio in the final product, a tin rich precursor mixture is required. This tin rich xanthate sample was shown to have a band gap of * 1.73 eV and a power conversion efficiency of 0.15 %.

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