Self-supporting super hydrophilic MgFe₂O₄ flexible fibers for Pb(II) adsorption

Flexible MgFe₂O₄ magnetic fibers were originally prepared by four spinning solutions using electrospinning technology together with sol–gel method, and applied to Pb(II) adsorption for the first time. The prepared MgFe₂O₄ fibers were flexible, super hydrophilic; and could be curled and folded at will. Maximum adsorption capacities of MgFe₂O₄ fibers prepared from the spinning solutions with CTAB contents of 0%, 4% and 8% for Pb(II) were 263.27, 276.87 and 283.13 mg/g, respectively. Among the MgFe₂O₄ based adsorbents, the flexible MgFe₂O₄ fibers prepared in this work exhibited the highest adsorption capacity for Pb(II). This indicated that the flexible fiber adsorbents were self-supporting in aqueous solutions without agglomeration, therefore fully exerting their adsorption active sites; and so, improve their adsorption capacities for pollutants. The saturation magnetizations of MgFe₂O₄ fibers prepared from 0%, 4% and 8% CTAB content spinning solutions were 6.7, 10.6, and 14.0 emu/g, respectively. After adsorption, the adsorbents could be quickly separated from the aqueous solutions by magnetic separation. Flexible fibers provide a new direction in avoiding agglomeration to maximize the adsorption capacity of the adsorbent.