This work demonstrates a simple strategy for producing highly selective adsorption magnetic ion imprinted mesoporous silica (MIIMS) nanocomposites. They have been functionalized by a g-(aminoethylamino)propyl chelating group for specific recognition and rapid removal of toxic heavy metal ions from wastewaters. The superparamagnetic Fe 3 O 4 nanocrystal was encapsulated in an imprinted mesoporous organosilica shell via a co-condensation synthesis method. The results of transmission electron microscopy (TEM) and small angle X-ray diffraction (XRD) confirmed that the imprinted mesoporous organosilica shell preserved a highly ordered 2D mesostructure. The Brunauer-Emmett-Teller (BET) analysis found the surface area was 946 m 2 g À1 . The saturated adsorption capacity of MIIMS toward cadmium reached up to 25.2 mg g À1 (0.224 mmol g À1 ) at pH 5.0. The adsorption of cadmium reached an equilibrium within 4.5 min. The results of a selectivity study revealed that the adsorption capacity for Cd 2+ is much high than other co-existing heavy metal ions. The adsorption efficiency of MIIMS was above 94.2% after six extraction-stripping cycles. The MIIMS can efficiently remove cadmium ions in water treatment applications. Fig. 2 (a) TEM image of MIIMS; (b) N 2 adsorption-desorption isotherm; (c) magnetization curves (inset picture: MIIMS suspended in DDW (left) and separated by an external magnet (right)).This journal is Fig. 9 Reusability of MIIMS (experimental conditions: 10 mL of 300 mg L À1 Cd 2+ solution at pH 5.0, 10 mg adsorbent, T ¼ 298 K). 8002 | RSC Adv., 2017, 7, 7996-8003 This journal is

We developed an effective and selective method to remove Cr(iii) ions in acidic effluents.

No abstract

In this work, ion imprinted technology incorporated with mesoporous silica materials (MCM-41) to obtain the novel specific adsorbent, ion imprinted mesoporous silica. Cr(VI) imprinted mesoporous silica (Cr(VI)IMS) was synthesized and used for adsorption studies and waste water application. A synthesized imidazolyl silane agent act as the functional monomer in the imprinted process to build up highly ordered functionalized imprinted materials. The chemical composition, thermal stability, porosity and highly ordered morphology were characterized by Fourier transform infrared spectroscopy (FTIR), solid state nuclear magnetic resonance(NMR), Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) respectively. The Brunauer-Emmett-Teller (BET) surface area was 1054.51 m2 g-1 in this study. The Cr(VI)IMS showed great adsorption capacity to hexavalent chromium ions in acidic solution up to 45.6 mg g-1. Cr(VI)IMS displayed much higher adsorption capacity to Cr(VI) ions than other negative ions. The relative selectivity coefficient was 2.56, higher than those of other anions (below 1.5). After eight adsorption-regeneration cycles, the adsorption efficiency of Cr(VI)IMS still reached 92.5%. The Cr(VI)IMS was found to exhibit equivalent property after multiple cycles of experiments, indicating good repeatability and reproducibility.

In this work, ion imprinted technology incorporated with mesoporous silica materials (MCM-41) to obtain the novel speci c adsorbent, ion imprinted mesoporous silica. Cr(VI) imprinted mesoporous silica (Cr(VI)IMS) was synthesized and used for adsorption studies and waste water application. A synthesized imidazolyl silane agent act as the functional monomer in the imprinted process to build up highly ordered functionalized imprinted materials. The chemical composition, thermal stability, porosity and highly ordered morphology were characterized by Fourier transform infrared spectroscopy (FTIR), solid state nuclear magnetic resonance(NMR), Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) respectively. The Brunauer-Emmett-Teller (BET) surface area was 1054.51 m 2 g -1 in this study. The Cr(VI)IMS showed great adsorption capacity to hexavalent chromium ions in acidic solution up to 45.6 mg g -1 . Cr(VI)IMS displayed much higher adsorption capacity to Cr(VI) ions than other negative ions. The relative selectivity coe cient was 2.56, higher than those of other anions (below 1.5). After eight adsorption-regeneration cycles, the adsorption e ciency of Cr(VI)IMS still reached 92.5%. The Cr(VI)IMS was found to exhibit equivalent property after multiple cycles of experiments, indicating good repeatability and reproducibility.