METHOD OF PRODUCING MAGNETIC LIQUID Russian patent published in 2018 - IPC H01F1/44 H01F1/28 

FIELD: chemistry.

SUBSTANCE: invention relates to colloid chemistry and can be used to produce magnetic fluids on a polymethylsiloxane base, used in magneto-liquid sealing devices. Method for obtaining a magnetic fluid includes obtaining highly dispersed magnetite particles by chemical coprecipitation, stabilization of highly dispersed magnetite particles when heated to a temperature of 50°C and stirring, washing of stabilized magnetite particles with acetone, followed by drying and dispersing the stabilized magnetite particles. Stabilization of magnetite particles is carried out with cyclopentanacetic acid, and the dispersion of stabilized magnetite particles is carried out in a polymethylsiloxane liquid. Before stabilization, the magnetite obtained is washed with distilled water to pH = 7. Drying and dispersing of the stabilized magnetite particles in the polymethylsiloxane liquid is carried out during peptization at a temperature of 80°C for 24 hours under vacuum. Polymethylsiloxane liquid PMS-100 is used as the polymethylsiloxane liquid.

EFFECT: technical result is obtaining of a magnetic fluid with high aggregative stability, stability in a magnetic field of 1,5 Tl for a long period of time, with a range of operating temperatures from -50°C to +200°C and saturation magnetization 20÷60 kA/m.

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