Acknowledgements

These data show that jet spraying makes consistently greater impacts than digital inkjet printing does, with the most significant impacts being on human toxicity, cancer effects, freshwater ecotoxicity, and climate change. The first two of these categories have been examined in more detail using USEtox calculations and the third category also has been examined using IPCC 110a calculations. These analyses reveal that their impacts derive almost entirely from the energy required by the production processes. This explains why jet spraying projects very high impact values since this process also is relatively energy-intensive. It is notable that the impacts of climate change and mineral, fossil and resource depletion reveal differences of >50% between the two production methods. Again, these significant differences are attributed to energy requirements. Three other categories (human toxicity, cancer effects, acidification, and particulate matter) also show nearly the same differential of ~50%. The single-score analysis, which is the average of all values in the 16 categories, shows that digital inkjet

Further, the calculation of the CO2 equivalents, carried out by the IPCC 100a method, demonstrates that jet spraying has a greater impact than digital inkjet printing by a difference of 3.42 kg CO2 versus 1.63 kg CO2. A final point of difference is that the application of the ILCD method reveals that NOx production demonstrates the same trend, with 2.10 g NOx from jet

The preceding LCA data suggest that the traditional method of jet spraying is considerably inferior to that of digital inkjet printing and that further detailed analysis of each step of the process is likely to improve the process and its outcomes commercially, environmentally, and

This work reports design, synthesis, and characterization of photocatalytic TiO2-coated tiles fabricated by the conventional jet spraying technique and the new technique of digital inkjet printing. The latter represents a significant improvement over the former, in that (1) it provides a more precise deposition as it utilizes piezoelectric heads to direct the suspension within an electrostatic field, (2) the microsized TiO2 powder strikes a medium that balances the small size advantageous for photocatalytic performance and the ability to resist solubility in the glass bonding to the tile against the large size that inhibits respirability, and (3) the topography of the digital inkjet-printed coating is less amenable to cell attachment and proliferation than

The performance data show that the digital inkjet-printed coating was significantly more effective than the jet-sprayed coating in ethanol photodegradation. While the same trend was observed for toluene photodegradation, the difference was not as significant owing to direct photolysis of this aromatic compound. Both coatings were highly effective in destroying E. coli but the antibacterial activity with photocatalysis (ΔR) of the digital inkjet-printed coating was significantly superior to that of the jet-sprayed coating. Similarly, the LCA analysis of the impact assessments reveals the multifarious advantages of the digital inkjet-printed tile.

printing is ~46% lower than jet spraying.

274 Titanium Dioxide - Material for a Sustainable Environment

performatively.

4. Conclusions

those of the jet-sprayed coating.

spraying and 1.65 g NOx from digital inkjet printing.

In memory of Benedetta Sacchi, a worthy researcher and a collaborator for years of the UNIMI research group. The authors would like to thank Dr. A. Carletti (Artest, Italy) for the antibacterial testing and Mr. R. Pellini (GranitiFiandre, Italy) for the preparation of the photocatalytic tiles. This research was supported financially by the LIFE+ Environment Policy and Governance project Digitalife LIFE13 ENV/IT/000140. The UNSW authors acknowledge the characterization facilities provided by the Mark Wainwright Analytical Centre, UNSW Sydney, Australia.
