posted on 2014-09-04, 00:00authored byLinan Xu, Fengzhu Lv, Yihe Zhang, Xinglong Luan, Qian Zhang, Qi An
Constructing stable and reliable
interfaces around pseudo two-dimensional
clay materials is a key process in achieving advanced and reliable
performance of related composite materials. However, the effective
surface modification of pseudo two-dimensional clay has been a challenging
research topic. In this study, we have developed an effective and
facile method for the interfacial modification of magnetic montmorillonite
(MMT) nanocomposite by using covalent layer-by-layer (LbL) assembly.
The method involves conventional LbL assembly around the magnetic
MMT followed by infiltration of a bifunctional photoactive small molecule
and then covalent cross-linking of the LbL multilayers upon UV irradiation.
After covalent LbL modification, the nanocomposite presented ample
organic species around its interfaces and displayed stable organic
interfaces even in extreme solution conditions such as in basic (pH
=14) solutions. The covalent cross-linking of the multilayers proved
to be indispensable in keeping the LbL multilayers stable around the
MMT composites. After modification, the composite particles kept their
magnetic properties. In addition, the release profile of the composite
particles for methyl blue indicated that the composite particles preserved
the capacity to carry loads and release them in retarded speed. This
method will potentially integrate the merits of LbL multilayers with
MMT to achieve advanced functional materials.