Ferrihydrite Nanoparticle Aggregation Induced by Dissolved Organic Matter
(2018) In Journal of Physical Chemistry A 122(38). p.7730-7738- Abstract
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... (More)
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.
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- author
- Gentile, Luigi LU ; Wang, Tao LU ; Tunlid, Anders LU ; Olsson, Ulf LU and Persson, Per LU
- organization
- publishing date
- 2018
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physical Chemistry A
- volume
- 122
- issue
- 38
- pages
- 9 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85053498897
- pmid:30165023
- ISSN
- 1089-5639
- DOI
- 10.1021/acs.jpca.8b05622
- project
- MICCS - Molecular Interactions Controlling soil Carbon Sequestration
- language
- English
- LU publication?
- yes
- id
- 7967dde7-2ca6-4a1e-974e-a0b43a5ec14b
- date added to LUP
- 2018-10-22 13:43:49
- date last changed
- 2024-05-27 19:39:53
@article{7967dde7-2ca6-4a1e-974e-a0b43a5ec14b, abstract = {{<p>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 <sup>5</sup>/<sub>3</sub>, which is in close agreement with our Fh and DOM-Fh results.</p>}}, author = {{Gentile, Luigi and Wang, Tao and Tunlid, Anders and Olsson, Ulf and Persson, Per}}, issn = {{1089-5639}}, language = {{eng}}, number = {{38}}, pages = {{7730--7738}}, publisher = {{The American Chemical Society (ACS)}}, series = {{Journal of Physical Chemistry A}}, title = {{Ferrihydrite Nanoparticle Aggregation Induced by Dissolved Organic Matter}}, url = {{http://dx.doi.org/10.1021/acs.jpca.8b05622}}, doi = {{10.1021/acs.jpca.8b05622}}, volume = {{122}}, year = {{2018}}, }