METHOD OF PRODUCING FERRIHYDRITE NANOPARTICLES Russian patent published in 2022 - IPC C01G49/02 B82B3/00 C12P3/00 B82Y40/00 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry, biology, medicine, plant growing and agriculture, and can be used in biological research, as well as for producing catalysts and sorbents, growth stimulants, crop yield enhancers, enhancers of fungicidal and bacteriological agents. Aerobic bacteria are cultivated in a mineral medium containing 2.5–10.0 g/l FeSO₄∙7H₂O and citric acid additive in amount of 1.5–8.0 g/l. Mineral medium can also include 0.1–0.5 g/l Co₃(C₆H₆O₇)₂, 0.5–2.5 g/l Al₂(SO₄)₃∙18H₂O or 1.5–6.0 g/l Na₂SiO₃∙9H₂O. Purification and extraction of obtained nanoparticles in form of sol is carried out by washing precipitate with water, purification from lipids and proteins by dispersion of precipitate in acetone using ultrasound. After holding and centrifuging, the precipitate is washed from acetone, dispersed in distilled water and subjected to alkaline hydrolysis in 0.5–1 % NaOH solution. Dispersed phase is washed with water to pH 7.7–8.3. Precipitate is dispersed by ultrasound, centrifuged and removed.

EFFECT: invention enables to obtain ferrihydrite nanoparticles in the form of a stable colloidal solution using a simple and environmentally friendly method.

4 cl, 7 dwg, 3 ex