Unraveling the Structure and Properties of High-Concentration Aqueous Iron Oxide Nanocolloids Free of Steric Stabilizers | Sciact - CRIS-system of Boreskov Institute of Catalysis

Unraveling the Structure and Properties of High-Concentration Aqueous Iron Oxide Nanocolloids Free of Steric Stabilizers Full article

Journal

Journal of the American Chemical Society
ISSN: 0002-7863 , E-ISSN: 1520-5126

Output data

Year: 2025, Volume: 147, Number: 10, Pages: 8467–8477 Pages count : 11 DOI: 10.1021/jacs.4c16602

Tags

MAGNETIC-PROPERTIES; NANOPARTICLES; NANOCRYSTALS; SUSPENSIONS; NANOFLUIDS; SCATTERING; PARTICLES; MAGHEMITE; ALKALINE; HEMATITE

Authors

Karpov Denis V. ^1,2 , Vorobyev Sergey A. ¹ , Bayukov Oleg A. ³ , Knyazev Yuriy V. ³ , Velikanov Dmitriy A. ³ , Zharkov Sergey M. ^2,3 , Larichev Yurii V. ⁴ , Saikova Svetlana V. ^1,2 , Zitoun David ^5,6 , Mikhlin Yuri ⁵

Affiliations

1	Institute of Chemistry and Chemical Technology, Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk 660036, Russia
2	Institute of Nonferrous Metals and Materials Science, Siberian Federal University, Krasnoyarsk 660041, Russia
3	Kirensky Institute of Physics, Krasnoyarsk Science Center of the Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk 660036, Russia
4	Boreskov Institute of Catalysis of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
5	Department of Chemistry, Bar-Ilan University, Ramat Gan 5290002, Israel
6	Bar-Ilan Institute of Nanotechnology and Advanced Materials (BINA), Bar-Ilan University, Ramat Gan 5290002, Israel

Funding (1)

Ministry of Science and Higher Education of the Russian Federation

FWES-2021-0014

Aqueous colloids with a high concentration of nanoparticles and free of steric stabilizers are prospective soft materials, the engineering of which is still challenging. Herein, we prepared superparamagnetic colloids with very large, up to 1350 g/L concentration of 11 nm nanoparticles via Fe2+ and Fe3+ coprecipitation, water washing, purification using cation-exchange resin, and stabilization with a monolayer of citrate anions (ζ potential of diluted dispersions about −35 mV). XRD, XPS, Mössbauer, and FTIR spectra elucidated the defective reverse spinel structure of magnetite/maghemite (Fe3O4/γ-Fe2O3) with a reduced content of Fe2+ cations. The viscosity increases with nanoparticle concentration and depends also on the nature of citrate salt, being one order of magnitude lower for lithium than sodium and potassium as counter-cation. SAXS/USAXS curves show power-law behavior in the scattering vector range between 0.1 and 0.002 nm–1, suggesting that particles interact forming fractal clusters, which are looser for Na+- and denser for Li+-citrate stabilizers (fractal dimensions of 1.9 and 2.4, respectively). In parallel, ATR-FTIR found increasing proportions of symmetric O–H stretching vibrations of ice-like interfacial water in the concentrated colloids. We hypothesize that the clusters arise due to the attraction of like-charge particles possibly involving the water shells and hydration of counter-cations; overlapping the clusters and transition to continuous non-Newtonian phases is seen at viscosity vs concentration plots at 700–900 g/L. The results shed new light on the structure of very concentrated nanocolloids and pave the way for their manufacturing and tailoring.

Karpov D.V. , Vorobyev S.A. , Bayukov O.A. , Knyazev Y.V. , Velikanov D.A. , Zharkov S.M. , Larichev Y.V. , Saikova S.V. , Zitoun D. , Mikhlin Y.
Unraveling the Structure and Properties of High-Concentration Aqueous Iron Oxide Nanocolloids Free of Steric Stabilizers
Journal of the American Chemical Society. 2025. V.147. N10. P.8467–8477. DOI: 10.1021/jacs.4c16602 WOS Scopus РИНЦ OpenAlex

Submitted:	Nov 22, 2024
Accepted:	Feb 25, 2025
Published online:	Mar 3, 2025
Published print:	Mar 12, 2025

Web of science:	WOS:001437057400001
Scopus:	2-s2.0-86000165270
Elibrary:	81020338
OpenAlex:	W4408131967

DB	Citing
Web of science	1
Scopus	1
OpenAlex	1