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Magnetic Pickering emulsions stabilized by Fe3O4 nanoparticles

Zhou, Jun; Qiao, Xiuying; Binks, Bernard P.; Sun, Kang; Bai, Mingwen; Li, Yunlong; Liu, Yi

Authors

Jun Zhou

Xiuying Qiao

Kang Sun

Mingwen Bai

Yunlong Li

Yi Liu



Abstract

Superparamagnetic Fe3O4 nanoparticles prepared by a classical coprecipitation method were used as the stabilizer to prepare magnetic Pickering emulsions, and the effects of particle concentration, oil/water volume ratio, and oil polarity on the type, stability, composition, and morphology of these functional emulsions were investigated. The three-phase contact angle (θ(ow)) of the Fe3O4 nanoparticles at the oil-water interface was evaluated using the Washburn method, and the results showed that for nonpolar and weakly polar oils of dodecane and silicone, θ(ow) is close to 90 degrees, whereas for strongly polar oils of butyl butyrate and 1-decanol, θ(ow) is far below 90 degrees. Inherently hydrophilic Fe3O4 nanoparticles can be used to prepare stable dodecane-water and silicone-water emulsions, but they cannot stabilize butyl butyrate-water and decanol-water mixtures with macroscopic phase separation occurring, which is in good agreement with the contact angle data. Emulsions are of the oil-in-water type for both dodecane and silicone oil, and the average droplet size increases with an increase in the oil volume fraction. For stable emulsions, not all of the particles are adsorbed to drop interfaces; the fraction adsorbed decreases with an increase in the initial oil volume fraction. Changes in the particle concentration have no obvious influence on the stability of these emulsions, even though the droplet size decreases with concentration.

Journal Article Type Article
Publication Date Apr 5, 2011
Journal LANGMUIR
Print ISSN 0743-7463
Electronic ISSN 1520-5827
Publisher American Chemical Society
Peer Reviewed Peer Reviewed
Volume 27
Issue 7
Pages 3308-3316
APA6 Citation Zhou, J., Qiao, X., Binks, B. P., Sun, K., Bai, M., Li, Y., & Liu, Y. (2011). Magnetic Pickering emulsions stabilized by Fe3O4 nanoparticles. Langmuir : the ACS journal of surfaces and colloids, 27(7), 3308-3316. doi:10.1021/la1036844
DOI https://doi.org/10.1021/la1036844
Keywords Responsive particulate emulsifiers; Iron-oxide nanoparticles; Silica particles; Phase inversion; Oil surfactant