Your browser has javascript turned off or blocked. This will lead to some parts of our website to not work properly or at all. Turn on javascript for best performance.

The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Per Persson. Photo.

Per Persson

Director

Per Persson. Photo.

Ferrihydrite Nanoparticle Aggregation Induced by Dissolved Organic Matter

Author

  • Luigi Gentile
  • Tao Wang
  • Anders Tunlid
  • Ulf Olsson
  • Per Persson

Summary, in English

Ferrihydrite (Fh) nanoparticles are omnipresent in nature and often highly mobile because of their colloidal stability. Thus, Fh serves as a vector for iron as well as associated nutrients and contaminants. Here, we demonstrate, using small-angle X-ray scattering combined with cryo-transmission electron microscopy (cryo-TEM), that dissolved organic matter (DOM), extracted from a boreal forest soil, induce aggregation of Fh nanoparticles, of radius 3 nm, into fractal aggregates, having a fractal dimension D = 1.7. The DOM consists of both fractal-like colloids (>100 nm) and small molecular DOM, but the attractive Fh interparticle interaction was mediated by molecular DOM alone as shown by cryo-TEM. This highlights the importance of using soil extracts, including all size fractions, in studies of the colloidal behavior of DOM-mineral aggregates. The Fh nanoparticles also self-assemble during synthesis into aggregates with the same fractal dimension as the DOM-Fh aggregates. We propose that, in both the absence and presence of DOM, the aggregation is controlled by the Fh particle charge, and the process can be viewed as a linear polymerization into a self-avoiding random walk structure. The theoretical D value for this is 5/3, which is in close agreement with our Fh and DOM-Fh results.

Department/s

  • MEMEG
  • Physical Chemistry
  • Centre for Environmental and Climate Science (CEC)
  • Microbial Ecology

Publishing year

2018

Language

English

Pages

7730-7738

Publication/Series

Journal of Physical Chemistry A

Volume

122

Issue

38

Document type

Journal article

Publisher

The American Chemical Society (ACS)

Topic

  • Physical Chemistry

Status

Published

Project

  • MICCS - Molecular Interactions Controlling soil Carbon Sequestration

Research group

  • Microbial Ecology

ISBN/ISSN/Other

  • ISSN: 1089-5639