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Updated: May 21, 2026
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Preparation of Nanoparticles for ToF-SIMS and XPS Analysis
Published on: September 13, 2020
Preparation and measurement methods for studying nanoparticle aggregate surface chemistry.
Christopher Szakal1, James A McCarthy, Melissa S Ugelow
1Surface and Microanalysis Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8371, USA. cszakal@nist.gov
Journal of Environmental Monitoring : JEM
|June 19, 2012
Summary
Environmental changes permanently alter nanoparticle (NP) surface chemistry. This study introduces methods to track the chemical memory of titanium dioxide (TiO2) NP aggregates, revealing how environments impact NP surfaces.
Area of Science:
- Environmental Science
- Materials Science
- Analytical Chemistry
Background:
- Nanoparticle (NP) surface chemistry is crucial for environmental interactions.
- Environmental exposure can create a lasting chemical signature on NPs.
- Understanding this 'chemical memory' is vital for assessing NP behavior.
Purpose of the Study:
- To develop foundational methods for studying the surface chemical memory of engineered NP aggregates.
- To bridge the gap between controlled laboratory studies and real-world NP samples.
- To investigate the impact of environmental factors on TiO2 NP surface chemistry.
Main Methods:
- Utilized well-characterized TiO2 NPs and inkjet printing for controlled aggregate formation.
- Employed scanning electron microscopy (SEM) for morphological analysis.
- Applied time-of-flight secondary ion mass spectrometry (ToF-SIMS) for surface chemical analysis.
- Developed a data analysis scheme for interpreting complex mass spectral data.
Main Results:
- Observed distinct mass spectral peak ratios for bare TiO2 NPs versus those exposed to natural organic matter (NOM) or pond water.
- Demonstrated that environmental factors subtly alter TiO2 NP surface chemistry.
- Identified changes in Ti(+)/TiO(+) and Ti(+)/C(3)H(5)(+) peak ratios as indicators of surface alteration.
- Explored differences between the surface and subsurface chemistry of NP aggregates.
Conclusions:
- The developed methods provide a robust framework for studying NP surface chemical memory.
- Environmental conditions significantly influence the surface chemistry of TiO2 NPs.
- These techniques can be adapted to monitor diverse engineered NPs in various environmental settings.
