Sub-micron-sized polyethylenimine-modified polystyrene/Fe 3 O 4 /chitosan magnetic composites for the efficient and recyclable adsorption of Cu(II) ions

Novel magnetically separable anhydride-functionalized Fe3O4@SiO2@PEI-NTDA nanoparticles as effective adsorbents: synthesis, stability and recyclable adsorption performance for heavy metal ions

“…24 PEI has usually been graed to other matrices such as insoluble polymers, 25 biomass, 26 and cellulose 27 to prevent its dissociation from the surface of the matrices during adsorption operations; it has also been used to construct magnetic hybrid nanomaterials for environmental applications in heavy metal ion removal. [28][29][30] In this work, to synthesize a magnetically separable adsorbent with high stability and adsorption capacity, a new type of magnetic silica material with amine and anhydridefunctionalized layers was fabricated by covalently graing a PEI polymer, followed by anhydride functionalization with 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTDA) onto the surface of Fe 3 O 4 @SiO 2 , as shown in Scheme 1. The PEI-NTDA layer on Fe 3 O 4 @SiO 2 not only endowed the nal magnetic adsorbents with hydrophilicity, reducing nonspecic adsorption during wastewater treatments, but also provided numerous amine and anhydride groups, which may synergistically coordinate or chelate with heavy metal ions.…”

Probing the interaction effects of metal ions in MnxFe(3−x)O4 on arsenite oxidation and adsorption

“…The diffraction patterns for the synthesized magnetite nanoparticles and manganese doped nanoparticles matched card data for magnetite (JCPDS 19-0629) with no peaks corresponding to secondary phases or impurities being detected. 37 As doping levels increased, diffraction peaks were shied to lower 2q values since the radius of Mn 2+ at 67 pm is larger than both Fe 2+…”

Novel adsorption model of filtration process in polycarbonate track-etched membrane: Comparative study

“…More recently, four research studies have shown that an error in the use of a pseudofirst-order kinetic model requires correction [15][16][17][18]. Moreover, Tseng and Wu [19] proposed a convenient method to determine kinetic parameters of adsorption processes by nonlinear regression of the PFO, PSO and pseudo-nth-order (PNO) equations with SigmaPlot 11 software.…”