Dimpled SiO2@γ-Fe2O3 nanocomposites – fabrication and use for arsenic adsorption in aqueous medium

Saruta Deeprasert (1, 2) , Lilin Wang (1, 2) , Konstantinos Simeonidis (3) , Nguyen Thi Kim Thanh (1, 2) , Etienne Duguet (4) , Stefanos Mourdikoudis (1, 2)

1 Department of Physics and Astronomy [UCL London]
2 UCL Healthcare Biomagnetic and Nanomaterials Laboratories
3 Aristotle University of Thessaloniki
4 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

We report the synthesis of nanocomposites made of silica nanoparticles whose six surface dimples are decorated with magnetic maghemite nanoparticles and their use for detection and recovery of arsenic in aqueous media. Precursor silica nanoparticles have aminated polystyrene chains at the bottom of their dimples and the maghemite nanoparticles are surface functionalized with carboxylic acid groups in two steps: amination with 3-aminopropyltrimethoxysilane, then derivatization with succinic anhydride in the presence of triethylamine. In the end, the colloidal assembly consists of the regioselective grafting of the carboxylic acid-modified iron oxide nanoparticles onto the 6-dimple silica nanoparticles. Several characterization techniques such as transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) are employed to assess the grafting process and study the influence of the maghemite functional groups on the quality of the composites formed. The resulting magnetic nanocomposites are used for the environmentally benign detection and removal of arsenic from aqueous medium, being readily extracted through means of magnetic separation.

Domaines: Matériaux

Saruta Deeprasert, Lilin Wang, Konstantinos Simeonidis, Nguyen Thi Kim Thanh, Etienne Duguet, et al.. Dimpled SiO2@γ-Fe2O3 nanocomposites – fabrication and use for arsenic adsorption in aqueous medium. RSC Advances, 2021, 11 (3), pp.1343-1353. ⟨10.1039/d0ra09907d⟩. ⟨hal-03131604⟩