Magnetic particles
OwnerManchium Chang, Michael S. Colvininventors
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Abstract
Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.
Claims13
A method of forming a magnetic polymeric material containing particles of magnetic metal oxide distributed throughout the material comprising the steps of:
- immersing a swellable, porous polymer in an aqueous solution of a metal salt which is a precursor of said particles of magnetic metal oxide, said metal salt being a salt of a strong acid and a metal ion selected from iron, cobalt or nickel;
- swelling the polymer in said solution while diffusing said metal containing salt solution into said pores;
- adding a strong base selected from a hydroxide of a Group I metal ion or ammonium to the solution;
- reacting the base with the metal salt within the pores to form finely-divided magnetic metal oxide particles within the pores of the polymeric material.
Dependencies are inferred from the claim text.