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Title: Aqueous Superparamagnetic Magnetite Dispersions with Ultrahigh Initial Magnetic Susceptibilities

Superparamagnetic nanoparticles with a high initial magneti susceptibility χo are of great interest in a wide variety of chemical, biomedical, electronic, and subsurface energy applications. In order to achieve the theoretically predicted increase in χ o with the cube of the magnetic diameter, new synthetic techniques are needed to control the crystal structure, particularly for magnetite nanoparticles larger than 10 nm. Aqueous magnetite dispersions (Fe 3O 4) with a χ o of 3.3 (dimensionless SI units) at 1.9 vol %, over 3- to 5-fold greater than those reported previously, were produced in a one-pot synthesis at 210 °C and ambient pressure via thermal decomposition of Fe(II) acetate in triethylene glycol (TEG). The rapid nucleation and focused growth with an unusually high precursor-to-solvent molar ratio of 1:12 led to primary particles with a volume average diameter of 16 nm and low polydispersity according to TEM. The morphology was a mixture of stoichiometric and substoichiometric magnetite according to X-ray diffraction (XRD) and Mössbauer spectroscopy. Finally, the increase in χ o with the cube of magnetic diameter as well as a saturation magnetization approaching the theoretical limit may be attributed to the highly crystalline structure and very small nonmagnetic layer (~1 nm) withmore » disordered spin orientation on the surface.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ; ORCiD logo [2] ;  [3] ;  [3] ;  [1] ;  [1] ;  [1] ;  [1] ;  [4] ; ORCiD logo [1] ; ORCiD logo [1]
  1. Univ. of Texas, Austin, TX (United States). McKetta Dept. of Chemical Engineering
  2. Boston Univ., MA (United States). Dept. of Chemistry
  3. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
  4. Univ. of Texas, Austin, TX (United States). Advanced Energy Consortium & Bureau of Economic Geology
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 34; Journal Issue: 2; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Welch Foundation
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; dispersion; magnetic susceptibility; magnetite; nucleation and growth; superparamagnetic
OSTI Identifier:
1459893

Fei, Yunping, Iqbal, Muhammad, Kong, Seong D., Xue, Zheng, McFadden, Charles P., Guillet, Jesse L., Doerrer, Linda H., Alp, Esen E., Bi, Wenli, Lu, Yi, Dandamudi, Chola B., Ranganath, Prashant J., Javier, Kevin J., Ahmadian, Mohsen, Ellison, Christopher J., and Johnston, Keith P.. Aqueous Superparamagnetic Magnetite Dispersions with Ultrahigh Initial Magnetic Susceptibilities. United States: N. p., Web. doi:10.1021/acs.langmuir.7b03702.
Fei, Yunping, Iqbal, Muhammad, Kong, Seong D., Xue, Zheng, McFadden, Charles P., Guillet, Jesse L., Doerrer, Linda H., Alp, Esen E., Bi, Wenli, Lu, Yi, Dandamudi, Chola B., Ranganath, Prashant J., Javier, Kevin J., Ahmadian, Mohsen, Ellison, Christopher J., & Johnston, Keith P.. Aqueous Superparamagnetic Magnetite Dispersions with Ultrahigh Initial Magnetic Susceptibilities. United States. doi:10.1021/acs.langmuir.7b03702.
Fei, Yunping, Iqbal, Muhammad, Kong, Seong D., Xue, Zheng, McFadden, Charles P., Guillet, Jesse L., Doerrer, Linda H., Alp, Esen E., Bi, Wenli, Lu, Yi, Dandamudi, Chola B., Ranganath, Prashant J., Javier, Kevin J., Ahmadian, Mohsen, Ellison, Christopher J., and Johnston, Keith P.. 2017. "Aqueous Superparamagnetic Magnetite Dispersions with Ultrahigh Initial Magnetic Susceptibilities". United States. doi:10.1021/acs.langmuir.7b03702. https://www.osti.gov/servlets/purl/1459893.
@article{osti_1459893,
title = {Aqueous Superparamagnetic Magnetite Dispersions with Ultrahigh Initial Magnetic Susceptibilities},
author = {Fei, Yunping and Iqbal, Muhammad and Kong, Seong D. and Xue, Zheng and McFadden, Charles P. and Guillet, Jesse L. and Doerrer, Linda H. and Alp, Esen E. and Bi, Wenli and Lu, Yi and Dandamudi, Chola B. and Ranganath, Prashant J. and Javier, Kevin J. and Ahmadian, Mohsen and Ellison, Christopher J. and Johnston, Keith P.},
abstractNote = {Superparamagnetic nanoparticles with a high initial magneti susceptibility χo are of great interest in a wide variety of chemical, biomedical, electronic, and subsurface energy applications. In order to achieve the theoretically predicted increase in χo with the cube of the magnetic diameter, new synthetic techniques are needed to control the crystal structure, particularly for magnetite nanoparticles larger than 10 nm. Aqueous magnetite dispersions (Fe3O4) with a χo of 3.3 (dimensionless SI units) at 1.9 vol %, over 3- to 5-fold greater than those reported previously, were produced in a one-pot synthesis at 210 °C and ambient pressure via thermal decomposition of Fe(II) acetate in triethylene glycol (TEG). The rapid nucleation and focused growth with an unusually high precursor-to-solvent molar ratio of 1:12 led to primary particles with a volume average diameter of 16 nm and low polydispersity according to TEM. The morphology was a mixture of stoichiometric and substoichiometric magnetite according to X-ray diffraction (XRD) and Mössbauer spectroscopy. Finally, the increase in χo with the cube of magnetic diameter as well as a saturation magnetization approaching the theoretical limit may be attributed to the highly crystalline structure and very small nonmagnetic layer (~1 nm) with disordered spin orientation on the surface.},
doi = {10.1021/acs.langmuir.7b03702},
journal = {Langmuir},
number = 2,
volume = 34,
place = {United States},
year = {2017},
month = {12}
}