Created with Sketch.

3. Jul 2017 | Coatings Technologies

Effect of UVA photocatalysis on soot-coated TiO2-containing mortars

If diesel soot is deposited on buildings, colour changes and unwanted black crusts can occur. A remedy is provided by self-cleaning systems based on TiO2 coatings. Can the irradiation of UVA light further improve the effect?

Effects of UVA photocatalysis on soot-coated TiO2-containing mortars. Source: Pixabay

In this study, the self-cleaning effect of TiO2-containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO2 (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30 days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state 13C NMR spectroscopy.

Self-cleaning effect ater UV exposure

The FESEM and colour spectrophotometry revealed that the soot-coated TiO2-containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and 13C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. The findings also revealed that the inclusion of TiO2 in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO2 and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition.

The study is published in: Science of The Total Environment, Volumes 605–606, 15 December 2017, Pages 147–157

EC Library The Rheology Handbook

Books

The Rheology Handbook

Already in its 5th edition, this standard work describes the principles of rheology clearly, vividly and in practical terms. The book includes the rheology of additives in waterborne dispersions and surfactant systems. Not only it is a great reference book, it can also serve as a textbook for studying the theory behind the methods. The practical use of rheology is presented in the areas quality control, production and application, chemical and mechanical engineering, materials science and industrial research and development. After reading this book, the reader should be able to perform tests with rotational and oscillatory rheometers and interpret the results correctly.

Tags

This could also be interesting for you!

0 Comments

You are currently not logged in

To leave a comment, please log in.

Login
For continuously improving and optimizing our websites, we use cookies. By using our website, you agree to the usage of cookies. For more information, please visit our Privacy policy.
Accept