Environmental Engineering Reference
In-Depth Information
Fig. 6.2 Key-lock relation in potential applications of magnetic composites particles
environmental applications, to antigen or streptavidin as in biological applica-
tions, while the key could be a specific ligand, antibody, or biotin. In this
communication, we focus on the research progress over the last ten years on
the development of magnetic nanocomposites particles as sorbent for industry
effluent management. The approaches such as molecular self-assembly (SA),
direct silanation, two-step silica coating, and mesoporous silica coating for
preparation of magnetic nanocomposites particles and their target applications
will be reviewed.
6.4 Methods for the Preparation of Magnetic Nanocomposites
6.4.1 Molecular Self-Assembly (SA)
SA is a process of spontaneous formation of a functionalized organic molecular
(surfactant) layer on an inorganic substrate in an organic or aqueous solvent
[49]. The preparation and characterization of self-assembled (SA) monolayer
coatings of various organic surfactants on flat metal or metal oxide surfaces
have been reported in a number of publications. These include alkysilane
surfactant on hydroxylated surfaces, such as silica and aluminum oxide; alka-
nethiolates on gold, silver, and copper; alcohol and amines on platinum; and
carboxylic and hydroxamic acids on aluminum oxide and silver oxide [50, 51,
52, 53, 54, 55, 56, 57, 58, 59]. In more recent publications, bolaamphiphiles with
two different reactive head groups at both ends of the molecule are used to
manipulate the architecture of organic films on flat metal or metal oxide
surfaces such as gold, silica, and aluminum oxide [60, 61, 62, 63, 64]. By
controlling the relative reactivity of the two functional groups with the surface,
one functional group can anchor chemically onto the surface and the other
remains reactive to target species. However, most of the fabrications of SA
monolayers are limited to flat substrates and few publications have described
