Method for silica encapsulation of magnetic particles
AssigneeInternational Business Machines Corporation
InventorsQiu Dai, Alshakim Nelson
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Abstract
Provided is a method of inhibiting magnetically induced aggregation of ferrimagnetic and/or ferromagnetic nanoparticles by encapsulating the nanoparticles in a silica shell. The method entails coating magnetic nanoparticle surfaces with a polyacid polymer to form polymer-coated magnetic nanoparticles and treating the polymer-coated magnetic nanoparticles with a silica precursor to form uniform silica-coated magnetic nanoparticles. By controlling the thickness of the silica encapsulating the nanoparticles, the inherent magnetically induced aggregation of the nanoparticles can be completely inhibited.
Claims25
A method comprising:
- (a) treating magnetic nanoparticles with a polyacid polymer to form polymer-coated magnetic nanoparticles and ionizing the polymer-coated magnetic nanoparticles with a base, and
- (b) reacting the polymer-coated magnetic nanoparticles with a silica precursor to form silica-coated magnetic nanoparticles,
- wherein magnetically induced aggregation of the magnetic nanoparticles of step (a) is completely inhibited by the silica-coating of step (b),
- wherein the magnetic nanoparticles are selected from the group consisting of ferrimagnetic nanoparticles and ferromagnetic nanoparticles.
A method comprising:
- (a) treating ferrimagnetic and/or ferromagnetic nanoparticles with poly(acrylic acid) (PAA) to form PAA-modified magnetic nanoparticles and ionizing the PAA-modified magnetic nanoparticles with a base;
- and
- (b) reacting the PAA-modified nanoparticles with tetramethylorthosilicate (TEOS) to form silica-coated magnetic nanoparticles,
- wherein magnetically induced aggregation of the magnetic nanoparticles of step (a) is completely inhibited by the silica-coating of step (b).
Dependencies are inferred from the claim text.