71st IUVSTA Workshop IUVSTA71 Abstracts Friday, June 28 65
Nanostructure Characterisation by Electron Beam Techniques Characterizing Nanoparticles for Environmental and Biological Applications D. R. Baer, * M. H. Engelhard, P. Munusamy, S. Thevuthasan EMSL Pacific Northwest National Laboratory, Richland, WA, USA *don.baer@pnnl.gov For the past decade we have been studying the behaviors of nanoparticles in environmental and biological systems. This presentation will summarize some of the frequent characterization challenges inherently associated with understanding nanomaterials in these environments and provide examples of how surface and other characterization methods have helped us address some of the challenges. There is increasing recognition that published reports on the properties and behaviors of nanomaterials have often involved inadequate characterization [1]. Consequently, the value of the data in many reports is, at best, uncertain. It is necessary for researchers to recognize the challenges associated with reproducible materials synthesis, maintaining desired materials properties during handling and processing, and the dynamic nature of nanomaterials at all stages of nanoparticle preparation, characterization and use [2]. Researchers also need to understand how characterization approaches (surface and otherwise) can be used to minimize synthesis surprises and to determine how (and how quickly) materials and properties change in different environments. Some of the needs and lessons we have learned examining the ability of iron metal-core oxide-shell nanoparticle to reduce environmental contaminants [3], observing the nature of ceria nanoparticles during synthesis and aging [4] as well as how they interact with biological systems and measuring the stability of silver nanoparticles in biological media will highlight both general analysis difficulties and the value of surface sensitive analysis methods in combination with other techniques [5]. Because nanoparticles are often synthesized, supplied or used in liquid media procedures to extract particles from the media maintaining as much of the desired information as possible is important to enable analysis from surface sensitive methods such as XPS to be valuable [3]. Equally important is the application of surface sensitive methods (such as sum frequency generation) that can characterize particle surface in solution [2]. References [1] R.M. Crist, J.H. Grossman, A.K. Patri, S.T. Stern, M.A. Dobrovolskaia, P.P. Adiseshaiah, J.D. Clogston, S.E. McNeil, Integrative Biology 5 (2013) 66-73. [2] D.R. Baer, et al., Journal of Vacuum Science & Technology A (2013) in press. [3] J. T. Nurmi, V. Sarathy, P. T. Tratnyek, D. R. Baer, J. E. Amonette and A. Karkamkar, J. Nanopart. Res. 13 (5) 1937-1952 (2010). [4] S. V. N. T. Kuchibhatla, A. S. Karakoti, D. R. Baer, S. Samudrala, M. H. Engelhard, J. E. Amonette, S. Thevuthasan and S. Seal, J. Phys. Chem. C 116 (26), 14108-14114 (2012). [5] D.R. Baer, D.J. Gaspar, P. Nachimuthu, S.D. Techane, D.G. Castner, Analytical and Bioanalytical Chemistry 396 (2010) 983-1002. 66