DBPapers
DOI: 10.5593/sgem2017H/63/S24.007

NITROLIGNOSULFONATES AS A MAGNETIC FLUID STABILIZER

V. Veshnyakov, N. Kuzyakov, Y. Khabarov
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-29-4 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 63, 55-60 pp; DOI: 10.5593/sgem2017H/63/S24.007

ABSTRACT

Nanoparticles of magnetic fluids are stabilized with various surfactants. Lignosulfonates are water-soluble byproducts of sulfite pulping process. The aim of our work is to estimate possibility of using nitrated lignosulfonates for stabilization of water-based magnetic fluid and determine optimal nitration conditions. Nitrolignosulfonates were synthesized by nitration of sodium lignosulfonates with nitric acid and the products without further purification were used for preparation of magnetic fluid. Magnetic nanoparticles were obtained by oxidation of part of iron(II) cations with excess amount of nitric acid and alkalization of the solution for condensation of magnetite. Lignosulfonates nitration was controlled with UV-Vis spectrophotometry. Magnetic activity formation of the synthesized magnetic fluids was measured using a Gouy balance mounted on an analytical balance. The nanoparticle size of magnetic fluid was estimated on a particle size analyzer in scattering light intensity mode. Lignosulfonates were easily nitrated at room temperature and their UV-Vis spectra did not change significantly after 5 min of nitration. If the nitration was at heating (100°C) the absorbance of reaction products solution was decreasing probably due to oxidation degrading of aromatic ring of lignosulfonates. When the nitration of lignosulfonates was carried out at room temperature (25°C) or at slight heating (50°C) the synthesized nitrolignosulfonates peptized the magnetic compound sediment with formation of magnetic fluid. Lignosulfonates nitrated at 100°C did not have peptizing properties. For the synthesis of the magnetic fluid with maximum magnetic activity nitration of lignosulfonates should be carried out at 25-50°C with consumption of nitric acid no more than 0.2 mol and consumption of iron(II) 23-27 mmol per 1 g of sodium lignosulfonates. The synthesized magnetic fluid has particle with size of 15-30 nm and is stable for a long time. Thus nitrolignosulfonates exhibit peptizing properties and can be used for stabilization of water-based magnetic fluids.

Keywords: lignosulfonates, nitration, magnetic fluid