Magnetic nanoparticles stimulation to enhance liquid-liquid two-phase mass transfer under static and rotating magnetic fields

Rotating magnetic field (RMF) was applied on a micromixer to break the laminar flow and induce chaotic flow to enhance mass transfer between two-immiscible organic and aqueous phases. The results of RMF were compared to those of static magnetic field (SMF). For this purpose, experiments were carried out in a T-micromixer at equal volumetric flow rates of organic and aqueous phases. Fe3O4 nanoparticles were synthesized by co-precipitation technique and they were dissolved in organic phase. Results obtained from RMF and SMF were compared in terms of overall volumetric mass transfer coefficient (K-La) and extraction efficiency (E) at various Reynolds numbers. Generally, RMF showed higher effect in mass transfer characteristics enhancement compared with SMF. The influence of rotational speeds of magnets (omega) in RMF was investigated, and measurable enhancements of K(L)a and E were observed. In RMF, the effect of magnetic field induction (B) was investigated. The results reveal that at constant concentration of nanoparticles, by increasing of B, mass transfer characteristics will be enhanced. The effect of various nanoparticles concentrations (phi) within 0.002-0.01 (w/v) on K(L)a and E at maximum induction of RMF (B=76 mT) was evaluated. Maximum values of K(L)a (2.1 +/- 0.001) and E (0.884 +/- 0.001) were achieved for the layout of RMF (B=76 mT), omega=16 rad/s and MNPs concentration of 0.008-0.01 (w/v). (C) 2016 Elsevier B.V. All rights reserved.