Selective Adsorption of Co(II) by Mesoporous Silica SBA‐15‐Supported Surface Ion Imprinted Polymer: Kinetics, Isotherms, and Thermodynamics Studies

Abstract

A novel surface ion imprinted adsorbent [Co(II)-IIP] using polyethyleneimine (PEI) as function monomer and ordered mesoporous silica SBA-15 as support matrix was prepared for Co(II) analysis with high selectivity. The prepared polymer was characterized by Fourier transmission infrared spectrometry, scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherm. Bath experiments of Co(II) adsorption onto Co(II)-IIP were performed under the optimum conditions. The experimental data were analyzed by pseudo-first-order and pseudo-second-order kinetic models. It was found that the pseudo-second-order model best correlated the kinetic data. The intraparticle diffusion and liquid film diffusion were applied to discuss the adsorption mechanism. The results showed that Co(II) adsorption onto IIP was controlled by the intraparticle diffusion mechanism, along with a considerable film diffusion contribution. Langmuir, Freundlich and Dubinin-Radushkevich adsorption models were applied to determine the isotherm parameters. Langmuir model fitted the experiment data well and the maximum calculated capacity of Co(II) reached 39.26 mg/g under room temperature. The thermodynamic data were indicative of the spontaneousness of the endothermic sorption process of Co(II) onto Co(II)-IIP. Co(II)-IIP showed high affinity and selectivity for template ion compared with non imprinted polymer (NIP).

Preparation of ion-imprinted mesoporous silica SBA-15 functionalized with triglycine for selective adsorption of Co(II)

“…The Co(II)-IIP showed an obvious advantage over other adsorbents. Compared with those Co(II)-imprinted polymers [23][24][25], Co(II)-IIP prepared in this study presented much higher adsorption capacity and excellent adsorptions rate, though its adsorption equilibrium time was not the shortest. In addition, when it comes to the common functionalized raw materials [40][41][42], higher Q e and good adsorption selectivity also made Co(II)-IIP stand out.…”

“…To overcome this, 2D imprinting method (surface-imprinting technique) has been used [20][21][22], since it provides an alternative way to improve mass transfer and reduce permanent entrapment of ions by imprinting on matrix surfaces. Taking adsorption capacity and equilibrium time into consideration, improvement are still possible for other similar type of adsorbents previously reported [23][24][25].…”

Effect of porogen solvent on the properties of nickel ion imprinted polymer materials prepared by inverse suspension polymerization

“…Table 2 summarizes the obtained results. Experimental data could not be fitted by the second order kinetic model, proving that chemisorption is not the limiting adsorption process of ions by the polymers [32,33]. The first order kinetic model, which assumes that the adsorption rate is proportional to the departure from equilibrium, could be successfully applied to nickel(II), zinc(II) and cobalt(II) adsorption but not to lead(II)…”

Ion-Imprinted Polymers: Synthesis, Characterization, and Adsorption of Radionuclides

“…steel: 51 Cr, 54 Mn, 60 Co, 63 Ni, 59 Fe, 93 Mo, 94 Nb, 108m,110m Ag, 124,125 Sb, 152 Eu, 166m Ho, -concrete: 36 Cl, 41 Ca, 46 Sc, 51 Cr, 59 Fe, 59 , 63 Ni, 60 Co, 65 Zn, 85 Sr, 124 Sb, 131 Cs, 152,154,155 Eu, 160 Tb, 181 Hf, 182 Ta.…”