Novel self assembly behavior for γ-alumina nanoparticles--颗粒学报PARTICUOLOGY

Saber, O. (2012). Novel self assembly behavior for γ-alumina nanoparticles. Particuology, 10(6), 744–750. https://doi.org/10.1016/j.partic.2012.03.008

Novel self assembly behavior for γ-alumina nanoparticles

Osama Saber^{a b *}

a Physics Dept, Faculty of Science, King Faisal University, Al-Hassa 31982, P.O. Box 400, Saudi Arabia
b Egyptian Petroleum Research Institute, Nasr City, P.O. Box 11727, Cairo, Egypt

10.1016/j.partic.2012.03.008

Volume 10, Issue 6, December 2012, Pages 744-750

Received 14 November 2011, Revised 1 March 2012, Accepted 6 March 2012, Available online 9 June 2012.

E-mail: osamasy@yahoo.com; osmohamed@kfu.edu.sa

Highlights

► γ-Alumina nanoparticles were prepared with average diameters of about 3–7 nm.

► By using low concentration of dimethyl disulfide (DMDS), self assembly of γ-alumina nanoparticles happened at room temperature in n-hexane, forming uniform and spherical granules in the range of 1–2 mm.

► Self assembly of the γ-alumina nanoparticles may be due to the selective adsorption of DMDS inside the micropores of the nanoparticles.

Abstract

In this study, self assembly behavior was induced for γ-alumina nanoparticles by adsorption of dimethyl disulfide. Following this trend, we have developed a chemical process to obtain γ-alumina in the nano scale. Scanning electron microscopy images of the prepared γ-alumina showed big and strong agglomeration of the nanoparticles indicating that these nanoparticles have strong surface forces. Transmission electron microscopy images confirmed that the γ-alumina nanoparticles 3–7 nm in size were converted to uniform spherical shape in the size range of 1–2 mm after shaking with dimethyl disulfide in the presence of n-hexane at room temperature. This phenomenon did not appear in the case of alumina in the micro scale. The surface properties of the prepared γ-alumina in the nano scale were characterized and compared with the γ-alumina in the micro scale by using low temperature nitrogen adsorption–desorption system, indicating that the specific surface area of the prepared γ-alumina nanoparticles is larger than that of the γ-alumina in the micro scale. Furthermore, micro- and meso-pores were observed for the γ-alumina nanoparticles while only mesoporous structure was detected for the γ-alumina in the micro scale. These experimental results suggested that the self assembly behavior of the γ-alumina nanoparticles may be due to the selective adsorption of dimethyl disulfide in the micropores of these nanoparticles to act as bridge linking the nanoparticles.

Graphical abstract

Keywords

γ-Alumina nanoparticles; Novel self assembly behavior; Scanning and transmission electron microscopy

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