Surface modification of magnetic nanoparticles capped by oleic acids: Characterization and colloidal stability in polar solvents

Sang Yup Lee, Michael T. Harris

Research output: Contribution to journalArticle

112 Citations (Scopus)

Abstract

The lyophobic surface of monodisperse magnetic nanoparticles capped by oleic acid was made to be more lyophilic by ozonolysis to increase the stability of the suspension in polar solvents like ethanol. The ozone oxidatively cleaved the double bond of oleic acid to form carbonyl and carboxyl groups on the surface of the nanoparticles. Additionally, interfacial ligand exchange of the capping molecules was applied to make the hydrophobic particle surface more hydrophilic. The magnetic particles showed enhanced miscibility and short-term stability in water after interfacial ligand exchange. The structure changes of the capping molecules on the nanoparticle surfaces were investigated using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). From these spectroscopy studies, the cleavage of the oleic acid and the formations of the carboxyl and carbonyl groups on the particle surface were confirmed. The shape and the magnetic properties of the nanoparticles were maintained after the surface modification. Ozonolysis is an effective method in modifying the lyophobic surface of the magnetic nanoparticles.

Original languageEnglish
Pages (from-to)401-408
Number of pages8
JournalJournal of Colloid and Interface Science
Volume293
Issue number2
DOIs
Publication statusPublished - 2006 Jan 15

Fingerprint

Oleic Acids
Oleic acid
Surface treatment
Nanoparticles
Oleic Acid
Ligands
Molecules
Ozone
Fourier transform infrared spectroscopy
Magnetic properties
Suspensions
Ethanol
X ray photoelectron spectroscopy
Solubility
Spectroscopy
Water

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

Cite this

@article{0f413cbf18a24d60ab5a239b62779160,
title = "Surface modification of magnetic nanoparticles capped by oleic acids: Characterization and colloidal stability in polar solvents",
abstract = "The lyophobic surface of monodisperse magnetic nanoparticles capped by oleic acid was made to be more lyophilic by ozonolysis to increase the stability of the suspension in polar solvents like ethanol. The ozone oxidatively cleaved the double bond of oleic acid to form carbonyl and carboxyl groups on the surface of the nanoparticles. Additionally, interfacial ligand exchange of the capping molecules was applied to make the hydrophobic particle surface more hydrophilic. The magnetic particles showed enhanced miscibility and short-term stability in water after interfacial ligand exchange. The structure changes of the capping molecules on the nanoparticle surfaces were investigated using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). From these spectroscopy studies, the cleavage of the oleic acid and the formations of the carboxyl and carbonyl groups on the particle surface were confirmed. The shape and the magnetic properties of the nanoparticles were maintained after the surface modification. Ozonolysis is an effective method in modifying the lyophobic surface of the magnetic nanoparticles.",
author = "Lee, {Sang Yup} and Harris, {Michael T.}",
year = "2006",
month = "1",
day = "15",
doi = "10.1016/j.jcis.2005.06.062",
language = "English",
volume = "293",
pages = "401--408",
journal = "Journal of Colloid and Interface Science",
issn = "0021-9797",
publisher = "Academic Press Inc.",
number = "2",

}

Surface modification of magnetic nanoparticles capped by oleic acids : Characterization and colloidal stability in polar solvents. / Lee, Sang Yup; Harris, Michael T.

In: Journal of Colloid and Interface Science, Vol. 293, No. 2, 15.01.2006, p. 401-408.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Surface modification of magnetic nanoparticles capped by oleic acids

T2 - Characterization and colloidal stability in polar solvents

AU - Lee, Sang Yup

AU - Harris, Michael T.

PY - 2006/1/15

Y1 - 2006/1/15

N2 - The lyophobic surface of monodisperse magnetic nanoparticles capped by oleic acid was made to be more lyophilic by ozonolysis to increase the stability of the suspension in polar solvents like ethanol. The ozone oxidatively cleaved the double bond of oleic acid to form carbonyl and carboxyl groups on the surface of the nanoparticles. Additionally, interfacial ligand exchange of the capping molecules was applied to make the hydrophobic particle surface more hydrophilic. The magnetic particles showed enhanced miscibility and short-term stability in water after interfacial ligand exchange. The structure changes of the capping molecules on the nanoparticle surfaces were investigated using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). From these spectroscopy studies, the cleavage of the oleic acid and the formations of the carboxyl and carbonyl groups on the particle surface were confirmed. The shape and the magnetic properties of the nanoparticles were maintained after the surface modification. Ozonolysis is an effective method in modifying the lyophobic surface of the magnetic nanoparticles.

AB - The lyophobic surface of monodisperse magnetic nanoparticles capped by oleic acid was made to be more lyophilic by ozonolysis to increase the stability of the suspension in polar solvents like ethanol. The ozone oxidatively cleaved the double bond of oleic acid to form carbonyl and carboxyl groups on the surface of the nanoparticles. Additionally, interfacial ligand exchange of the capping molecules was applied to make the hydrophobic particle surface more hydrophilic. The magnetic particles showed enhanced miscibility and short-term stability in water after interfacial ligand exchange. The structure changes of the capping molecules on the nanoparticle surfaces were investigated using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). From these spectroscopy studies, the cleavage of the oleic acid and the formations of the carboxyl and carbonyl groups on the particle surface were confirmed. The shape and the magnetic properties of the nanoparticles were maintained after the surface modification. Ozonolysis is an effective method in modifying the lyophobic surface of the magnetic nanoparticles.

UR - http://www.scopus.com/inward/record.url?scp=27744545722&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=27744545722&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2005.06.062

DO - 10.1016/j.jcis.2005.06.062

M3 - Article

C2 - 16054635

AN - SCOPUS:27744545722

VL - 293

SP - 401

EP - 408

JO - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

IS - 2

ER -