1 research outputs found
Superparamagnetic-Oil-Filled Nanocapsules of a Ternary Graft Copolymer
Stearic
and oleic acid-coated Fe<sub>3</sub>O<sub>4</sub> nanoparticles were
dispersed in decahydronaphthalene (DN). This oil phase was dispersed
in water using ternary graft copolymer polyÂ(glycidyl methacrylate)-<i>graft</i>-[polystyrene-<i>ran</i>-(methoxy polyethylene
glycol)-<i>ran</i>-polyÂ(2-cinnamoyloxyethyl methacrylate)]
or PGMA-<i>g</i>-(PS-<i>r</i>-MPEG-<i>r</i>-PCEMA) to yield capsules. The walls of these capsules were composed
of PCEMA chains that were soluble in neither water nor DN, and the
DN-soluble PS chains stretched into the droplet phase and the water-soluble
MPEG chains extended into the aqueous phase. Structurally stable capsules
were prepared by photolyzing the capsules with UV light to cross-link
the PCEMA layer. Both the magnetite particles and the magnetite-containing
capsules were superparamagnetic. The sizes of the capsules increased
as they were loaded with more magnetite nanoparticles, reaching a
maximal loading of ∼0.5 mg of ligated magnetite nanoparticles
per mg of copolymer. But the radii of the capsules were always <100
nm. Thus, a novel nanomaterialî—¸superparamagnetic-oil-filled
polymer nanocapsulesî—¸was prepared. The more heavily loaded
capsules were readily captured by a magnet and could be redispersed
via shaking. Although the cross-linked capsules survived this capturing
and redispersing treatment many times, the un-cross-linked capsules
ruptured after four cycles. These results suggest the potential to
tailor-make capsules with tunable wall stability for magnetically
controlled release applications