20-21 November 2014
National Centre for Synchrotron Science
Australia/Melbourne timezone
Save the date: User Meeting 2015 - 26-27 November

Investigations into the environmental transformations of silver nanoparticles

21 Nov 2014, 09:00
Oliphant Auditorium ()

Oliphant Auditorium


Dr Ryo Sekine (University of South Australia)


Silver nanoparticles (Ag-NPs) constitute a major group of engineered nanomaterials increasingly found in consumer products. These products exploit the unique properties of Ag-NPs such as their antibacterial effects, special optical properties, and high specific surface area and reactivity. However, there are significant concerns regarding the potential for Ag-NPs to pose equally unique risks upon their release to the environment. For example, Ag-NPs may have direct ecotoxicological effects, and they may also release ionic Ag, which is highly toxic to a range of organisms. As AgNP toxicity, dissolution, and speciation are likely to change in response to the surrounding environmental conditions, understanding the transformations of Ag-NPs in major release pathways and environmental endpoints is critical to assessing their potential risks. To this end, we have developed a series of nano in situ deployment devices (nIDDs) and used them to investigate the transformations of Ag-NPs in a range of environments. Following in situ deployment, during which the Ag-NPs on the nIDDs were directly exposed to relevant environments, the devices were retrieved and X-ray Absorption Spectroscopy (XAS) was used to determine the speciation of the exposed Ag-NPs. This revealed that Ag sulfide NPs are major transformation products forming from Ag-NPs in a wide range of environments. Subsequent XAS-based research showed that Ag sulfide is a stable, long term species of Ag reaching major environmental endpoints such as soil, which mitigates the potential ecological risks posed by the environmental release of Ag-NPs.
Keywords or phrases (comma separated) Silver nanoparticles, silver sulfide, transformations, fate, nIDDs, XAS

Primary author

Dr Ryo Sekine (University of South Australia)


Prof. Enzo Lombi (University of South Australia) Dr Erica Donner (University of South Australia) Dr Krasimir Vasilev (University of South Australia) Ms Maryam Khaksar (University of South Australia)

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