Using Nitrated Lignosulfonates for the Synthesis of a Water-Based Magnetic Fluid

Abstract

Nitrated lignosulfonates were used to synthesize a water-based magnetic fluid. Lignosulfonates were nitrated by nitric acid under mild conditions and without further purification were used to synthesize a magnetic fluid. Part of the iron(II) were oxidized with an excess of nitric acid, so that the magnetoactive phase under the condensation by action of sodium hydroxide was formed. Optimum conditions for nitration of lignosulfonates and synthesis of a magnetic fluid were experimentally established. The optimum consumption of iron(II) was 1.3–1.5[Formula: see text]g per 1[Formula: see text]g of sodium lignosulfonate. Unlike the initial lignosulfonates, nitrated lignosulfonates have peptizing properties, due to which the precipitate formed during condensation was dispersed to nanoparticles (15–30[Formula: see text]nm). The resulting magnetic fluid had a high magnetic activity and was stable for a long time.