AVS 63rd International Symposium & Exhibition
    Applied Surface Science Thursday Sessions
       Session AS-ThA

Paper AS-ThA3
The Secret Life of Nanoparticles: Often Ignored Characteristics of Nano-Objects That Limit Reproducibility and an Approach to Improving Data Collection and Reporting to Address the Challenges

Thursday, November 10, 2016, 3:00 pm, Room 101B

Session: Advances for Complicated Sample Preparation Strategies and Complex Systems
Presenter: Donald Baer, Pacific Northwest National Laboratory
Correspondent: Click to Email
The literature is filled with images of nanoparticles and nanostructured materials along with descriptions of how they were synthesized and some aspects of their new and exciting properties. However, nano-objects present fundamental synthesis, characterization, and handling challenges that are often ignored or unrecognized by parts of the scientific and technical community. The frequent tendency of such particles to interact with surrounding media and to respond to environmental changes complicates understanding their properties as a function of time in different environments but also presents interesting opportunities for the design of particles with desired time dependent properties. Particle variation due to time and environmentally dependent changes raise a number of issues associated with particle preparation for analysis, especially surface analysis. Issues include knowing the nature of changes and the rate at which they change after synthesis, during storage and processing, and in different media. This presentation will highlight some of the behaviors of nanoparticles we have observed drawing on research on Fe oxide-shell metal-core, ceria, and Ag nanoparticles. Examples will include the impact of particle structure on the dissolution and toxicity of Ag nanoparticles, the environmentally induced changes in the chemical state of ceria nanoparticles and the impact of synthesis details on the ability of iron metal-core oxide-shell particles to reduce contaminants in ground water. Some of the inconsistences in the literature are aggravated by the under-recording and under-reporting details of particle synthesis and handling. An ISO standard being developed to help address the problem will be described. This draft document includes both a standard on reporting of the preparation of particles for surface analysis and information about a range of sample preparation methods optimized for the types of information desired. One focus of the document is in on the extraction of nanoparticles from solution for analysis of surface coatings.