Functionalized magnetite particles for adsorption of colloidal noble metal nanoparticles

authors	Joana L. Lopes; karine L. Marques; Ana V. Girao; Eduarda Pereira and Tito Trindade
nationality	International
journal	JOURNAL OF COLLOID AND INTERFACE SCIENCE
author keywords	Magnetite; Nanoparticles; Nanometals; Magnetic separation
keywords	WASTE-WATER TREATMENT; SUPERPARAMAGNETIC NANOPARTICLES; ENGINEERED NANOPARTICLES; GOLD NANOPARTICLES; REMOVAL; NANOMATERIALS; NANOTECHNOLOGY; ENVIRONMENT; CHEMISTRY; ACIDS
abstract	Magnetite (inverse spinel type) particles have been surface-modified with siliceous shells enriched in dithiocarbamate groups. The deposition of colloidal noble metal nanoparticles (Au, Ag, Pt, Pd) onto the modified magnetites can be performed by treating the respective hydrosols with the magnetic sorbents, thus allowing their uptake from water under a magnetic gradient. In particular, for Au colloids, these magnetic particles are very efficient sorbents that we ascribe to the strong affinity of sulfur-containing groups at the magnetite surfaces for this metal. Considering the extensive use of Au colloids in laboratorial and industrial contexts, the approach described here might have an impact on the development of nanotechnologies to recover this precious metal. En route to these findings, we varied several operational parameters in order to investigate this strategy as a new bottom-up assembly method for producing plasmonic-magnetic nanoassemblies. (C) 2016 Elsevier Inc. All rights reserved.
publisher	ACADEMIC PRESS INC ELSEVIER SCIENCE
issn	0021-9797
year published	2016
volume	475
beginning page	96
ending page	103
digital object identifier (doi)	10.1016/j.jcis.2016.04.046
web of science category	Chemistry, Physical
subject category	Chemistry
unique article identifier	WOS:000376708400011