METHOD OF PRODUCING WATER BASED MAGNETIC LIQUID Russian patent published in 2009 - IPC C01G49/08 H01F1/28 

FIELD: chemistry.

SUBSTANCE: invention relates to design of colloidal systems and can be used in different engineering fields. The method of producing water based magnetic liquid involves precipitation of magnetite from salts of di- and trivalent iron FeCI₂·4H₂O and FeCI₃·6H₂O using excess concentrated solution of ammonia, addition of sodium oleate to the aqueous magnetite suspension, heating the suspension and boiling while stirring constantly, cooling and centrifuging the mixture. Sodium oleate is used as a stabiliser and surfactant, the adsorption layer of which covers the surface of magnetite particles. Alternating magnetic field at frequency of 50 Hz acts on the aqueous magnetite suspension.

EFFECT: invention improves magnetic characteristics of magnetic liquid and allows for not using dodecylamine stabiliser which is expensive and difficult to obtain.

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