tened and the resulting image file was opened in Photoshop®, where a ... Assignment of particles to clusters was accomplished using the Graph plugin, in ..... 21 B. Tupper, Graph, 2010. http://imagej.nih.gov/ij/plugins/graph/index.html.
PAPER
www.rsc.org/faraday_d | Faraday Discussions
Aggregation of ferrihydrite nanoparticles in aqueous systems Virany M. Yuwono, Nathan D. Burrows, Jennifer A. Soltis, Tram Anh Do and R. Lee Penn* Received 6th June 2012, Accepted 8th June 2012 DOI: 10.1039/c2fd20115a
Crystal growth by non-classical mechanisms, such as oriented aggregation, frequently involves an aggregation step. The aggregation of nanoparticles is sensitive to solution variables like ionic strength and pH, as well as the presence and concentration of other chemical species. Aggregation is a critical first step during the early stages of oriented aggregation. Time-resolved, cryogenic transmission electron microscopy was employed to characterize the degree of aggregation, the reversibility of aggregation, and the influence of additives on aggregation in aqueous suspensions. In this work, freshly synthesized ferrihydrite nanoparticles in aqueous suspension were employed as the model system. These nanoparticles are largely aggregated even with a solution pH several pH units away from the point of zero net proton charge (PZNPC) and a very low ionic strength (
