What’s in those socks? A synchrotron outreach study to analyze the properties of zinc in textiles under environmental pressure
Authors:
- Students:
- Rehman Arif
- Theo Calafeteanu
- Amanda Hahn
- Jack Meyers
- Catherine Sommerfeld
- Teachers:
- Michelle Harbin
- Mentors:
- Debora Motta Meira (Canadian Light Source, Advanced Photon Source)
Advanced Photon Source Sector 20: Spectroscopy Group
Zinc and silver are very similar in antimicrobial properties However, when exposed to bacteria zinc rusts, pulling electrons out from the cell wall of bacteria. The cell wall falls apart, thus killing the bacteria. As for silver, it is known to bind to bacteria which prevents it from performing basic functions.
The recent development of antimicrobial textiles, as well as research confirming harmful environmental effects of silver nanomaterials (Ag-NMs) in the textiles has gathered concern
on the use of zinc nanomaterials (Zn-NMs) in similar antimicrobial textiles. Various experiments have gathered data that the Ag-NMs decreased within the textile (sock) after wear, and it is believed the same will happen for Zn-NMs. If so, very little is known about the transformation of the zinc structure as the textile is worn, and the environmental impact also can be harmful.
For our experiment, we tested the properties of zinc with the use of zinc infused socks in exercise and washing cycles. We looked for zinc in different oxidation states (such as oxides), and if these states can be harmful for the environment if drained into the sewers. Our experimental groups consisted of light exercise (walking) and rigorous exercise (running) groups. Our control groups were an unused sock that is washed and an unused sock that is not washed The socks were washed in the same washing machine as well as the same load. Each wash was one normal cycle and at the same temperature. The same detergent was used and the detergent was unscented.
At APS x-ray spectroscopy was used to analyze zinc’s properties after exercise and the washing cycle. We looked for new states that could be potentially harmful for the environment and how much of the zinc would be lost from the sock into the environment. The x-rays gave us a first-hand look at our zinc samples in fabrics of our experimental groups. These gave us a baseline if zinc can produce a less harmful alternative to silver.