Quaternization of Poly(2-diethyl aminoethyl methacrylate) Brush-Grafted Magnetic Mesoporous Nanoparticles Using 2-Iodoethanol for Removing Anionic Dyes

Magnetic mesoporous silica nanoparticles (Fe3O4-MSNs) were successfully synthesized with a relatively high surface area of 568 m2g−1. Fe3O4-MSNs were then modified with poly(2-diethyl aminoethyl methacrylate) (PDEAEMA) brushes using surface-initiated ARGET atom transfer radical polymerization (ATRP) (Fe3O4@MSN-PDMAEMA). Since the charge of PDEAEMA is externally regulated by solution pH, tertiary amines in the polymer chains were quaternized using 2-iodoethanol to obtain cationic polymer chains with a permanent positive charge (Fe3O4@MSN-QPDMAEMA). The intensity of the C−O peak in the C1s X-ray photoelectron spectrum increased after reaction with 2-iodoethanol, suggesting that the quaternization process was successful. The applicability of the synthesized materials on the removal of methyl orange (MO), and sunset yellow (E110) dyes from an aqueous solution was examined. The effects of pH, contact time, and initial dyes concentrations on the removal performance were investigated by batch experiments. The results showed that the Fe3O4@MSN-PDMAEMA sample exhibited a weak adsorption performance toward both MO and E110, compared with Fe3O4@MSN-QPDMAEMA at a pH level above 5. The maximum adsorption capacities of MO and E110 using Fe3O4@MSN-QPDMAEMA were 294 mg g−1 and 194.8 mg g−1, respectively.