Abstract
Magnetite nanoparticles were coated with surfactant double layers in order to prepare water based magnetic fluids (MFs). The effects of head group (sulfonate, carboxylate) and alkyl chain length (11-17C atoms) and the combination of surfactants were studied. Adsorption, dynamic light scattering (DLS) and electrophoretic mobility measurements were performed. The quantity of surfactant varied between 0.3 and 0.5g, i.e.their specific amount ranges over 1.5-2mmolg-1 magnetite in MFs. The adsorption isotherm of Naoleate on magnetite proved the double layer formation with 2mmolg-1 saturation value in good harmony with the empirical doses. The effect of diluting MFs, pH and salt concentration was studied. The pH-dependent stability and the salt tolerance of MFs were different owing to the dissociation of the outermost hydrophilic groups and the hydrophobic interactions scaling with the alkyl chain length of surfactant. The hydrophobic interactions are favored only for oleic and myristic acid double layers. In these MFs, aggregation cannot be observed even in fairly dilute systems up to the physiological salt concentration around neutral pH 6-8 favored in biomedical application. The stable oleic and myristic acid double layers can hinder effectively the aggregation of magnetite particles due to the combined steric and electrostatic stabilization.
| Original language | English |
|---|---|
| Article number | 204103 |
| Journal | Journal of Physics Condensed Matter |
| Volume | 20 |
| Issue number | 20 |
| DOIs | |
| Publication status | Published - May 21 2008 |
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ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
Cite this
Surfactant double layer stabilized magnetic nanofluids for biomedical application. / Tombácz, E.; Bica, D.; Hajdú, A.; Illés, E.; Majzik, A.; Vékás, L.
In: Journal of Physics Condensed Matter, Vol. 20, No. 20, 204103, 21.05.2008.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Surfactant double layer stabilized magnetic nanofluids for biomedical application
AU - Tombácz, E.
AU - Bica, D.
AU - Hajdú, A.
AU - Illés, E.
AU - Majzik, A.
AU - Vékás, L.
PY - 2008/5/21
Y1 - 2008/5/21
N2 - Magnetite nanoparticles were coated with surfactant double layers in order to prepare water based magnetic fluids (MFs). The effects of head group (sulfonate, carboxylate) and alkyl chain length (11-17C atoms) and the combination of surfactants were studied. Adsorption, dynamic light scattering (DLS) and electrophoretic mobility measurements were performed. The quantity of surfactant varied between 0.3 and 0.5g, i.e.their specific amount ranges over 1.5-2mmolg-1 magnetite in MFs. The adsorption isotherm of Naoleate on magnetite proved the double layer formation with 2mmolg-1 saturation value in good harmony with the empirical doses. The effect of diluting MFs, pH and salt concentration was studied. The pH-dependent stability and the salt tolerance of MFs were different owing to the dissociation of the outermost hydrophilic groups and the hydrophobic interactions scaling with the alkyl chain length of surfactant. The hydrophobic interactions are favored only for oleic and myristic acid double layers. In these MFs, aggregation cannot be observed even in fairly dilute systems up to the physiological salt concentration around neutral pH 6-8 favored in biomedical application. The stable oleic and myristic acid double layers can hinder effectively the aggregation of magnetite particles due to the combined steric and electrostatic stabilization.
AB - Magnetite nanoparticles were coated with surfactant double layers in order to prepare water based magnetic fluids (MFs). The effects of head group (sulfonate, carboxylate) and alkyl chain length (11-17C atoms) and the combination of surfactants were studied. Adsorption, dynamic light scattering (DLS) and electrophoretic mobility measurements were performed. The quantity of surfactant varied between 0.3 and 0.5g, i.e.their specific amount ranges over 1.5-2mmolg-1 magnetite in MFs. The adsorption isotherm of Naoleate on magnetite proved the double layer formation with 2mmolg-1 saturation value in good harmony with the empirical doses. The effect of diluting MFs, pH and salt concentration was studied. The pH-dependent stability and the salt tolerance of MFs were different owing to the dissociation of the outermost hydrophilic groups and the hydrophobic interactions scaling with the alkyl chain length of surfactant. The hydrophobic interactions are favored only for oleic and myristic acid double layers. In these MFs, aggregation cannot be observed even in fairly dilute systems up to the physiological salt concentration around neutral pH 6-8 favored in biomedical application. The stable oleic and myristic acid double layers can hinder effectively the aggregation of magnetite particles due to the combined steric and electrostatic stabilization.
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U2 - 10.1088/0953-8984/20/20/204103
DO - 10.1088/0953-8984/20/20/204103
M3 - Article
VL - 20
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
SN - 0953-8984
IS - 20
M1 - 204103
ER -