Structured ZnO and Al2O3/Ag Surfaces: Antibacteriality, Photocatalytic Activity and Durability
Söyrinki, Saara (2018)
Söyrinki, Saara
Tampere University of Technology
2018
Rakennetun ympäristön tiedekunta - Faculty of Built Environment
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Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-15-4276-3
https://urn.fi/URN:ISBN:978-952-15-4276-3
Tiivistelmä
Functional coatings, i.e. coatings that possess a property that adds a desirable function onto a surface, offer great potential in numerous situations when specific requirements of a material must be fulfilled. Self-cleaning and antibacterial properties are useful in many cases, for instance in factories to reduce costs caused by washing processes or in hospitals to prevent bacterial infections. The self-cleaning property can be obtained with superhydrophobic, in other words highly water repellent, coatings. Besides the superhydrophobic surface, a photocatalytic surface also possesses self-cleaning capability. Photocatalysis is a phenomenon induced by light that can lead to oxidation and reduction reactions and further decomposition of organic pollutants. Photocatalytic surfaces exhibit antibacterial properties. There are also numerous metals that possess antibacterial properties, especially in the form of nanoparticles. In fact, silver is one of the most studied and used metal in antibacterial applications.
In this study, we have prepared, analyzed, and investigated the properties of two selfcleaning, antibacterial surfaces: a superhydrophobic silver-containing coating and a photocatalytic ZnO film. ZnO is a photocatalyst with an additional antibacterial property that is attributed to its semiconductor properties, in addition to the toxicity of zinc ions against bacteria. In this work, we have demonstrated a route for preparing superhydrophobic silver-containing coatings and studied their antibacterial efficiency. We have also studied the effect of synthesis parameters on the structure of ZnO films. The influence of the structure of the ZnO film on functional properties, photocatalytic, and antibacterial activity has also been investigated. Moreover, we have demonstrated the functionality of silvercontaining superhydrophobic surfaces as effective antibacterial coatings. The approach of using two functional mechanisms, superhydrophobicity and antibacterial silver, offers great potential for self-cleaning applications. In addition, this study shows the antibacterial effectiveness of ZnO in dark conditions as well as the relatively high photocatalytic activity of structured ZnO films, on the basis of which we can anticipate enhanced antibacterial activity under irradiation. The chemical stability of the surfaces has been investigated in order to estimate the usability of the surfaces in varying environments. Based on the knowledge obtained in this study, the prospects of using superhydrophobic silvercontaining coatings and ZnO films in applications requiring antibacterial and self-cleaning properties are discussed.
In this study, we have prepared, analyzed, and investigated the properties of two selfcleaning, antibacterial surfaces: a superhydrophobic silver-containing coating and a photocatalytic ZnO film. ZnO is a photocatalyst with an additional antibacterial property that is attributed to its semiconductor properties, in addition to the toxicity of zinc ions against bacteria. In this work, we have demonstrated a route for preparing superhydrophobic silver-containing coatings and studied their antibacterial efficiency. We have also studied the effect of synthesis parameters on the structure of ZnO films. The influence of the structure of the ZnO film on functional properties, photocatalytic, and antibacterial activity has also been investigated. Moreover, we have demonstrated the functionality of silvercontaining superhydrophobic surfaces as effective antibacterial coatings. The approach of using two functional mechanisms, superhydrophobicity and antibacterial silver, offers great potential for self-cleaning applications. In addition, this study shows the antibacterial effectiveness of ZnO in dark conditions as well as the relatively high photocatalytic activity of structured ZnO films, on the basis of which we can anticipate enhanced antibacterial activity under irradiation. The chemical stability of the surfaces has been investigated in order to estimate the usability of the surfaces in varying environments. Based on the knowledge obtained in this study, the prospects of using superhydrophobic silvercontaining coatings and ZnO films in applications requiring antibacterial and self-cleaning properties are discussed.
Kokoelmat
- Väitöskirjat [4891]