scholarly journals Highly Selective Copper Ion Imprinted Clay/Polymer Nanocomposites Prepared by Visible Light Initiated Radical Photopolymerization

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 286 ◽  
Author(s):  
Radhia Msaadi ◽  
Gorkem Yilmaz ◽  
Andrit Allushi ◽  
Sena Hamadi ◽  
Salah Ammar ◽  
...  

There is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu2+ ions in an aqueous solution. The Cu2+-imprinted polymer/montmorillonite (IIP/Mt) and non-imprinted polymer/montmorillonite (NIP/Mt) nanocomposites were prepared by a radical photopolymerization process in visible light. The ion imprinting step was indeed important as the recognition of copper ions by IIP/Mt was significantly superior to that of NIP/Mt, i.e., the reference nanocomposite synthesized in the same way but in the absence of Cu2+ ions. The adsorption process as batch study was investigated under the experimental condition affecting same parameters such as contact time, concentration of metal ions, and pH. The adsorption capacity of Cu2+ ions is maximized at pH 5. Removal of Cu2+ ion achieved equilibrium within 15 min; the results obtained were found to be fitted by the pseudo-second-order kinetics model. The equilibrium process was well described by the Langmuir isothermal model and the maximum adsorption capacity was found to be 23.6 mg/g. This is the first report on the design of imprinted polymer nanocomposites using Type II radical initiators under visible light in the presence of clay intercalated with hydrogen donor diazonium. The method is original, simple and efficient; it opens up new horizons in the general domain of clay/polymer nanocomposites.

Author(s):  
Radhia Msaadi ◽  
Gorkem Yilmaz ◽  
Andrit Allushi ◽  
Sena Hamadi ◽  
Salah Ammar ◽  
...  

There is an urgent demand worldwide for the development of highly selective adsorbents and sensors of heavy metal ions and other organic pollutants. Within these environmental and public health frameworks, we are combining the salient features of clays and chelatant polymers to design selective metal ion adsorbents. Towards this end, the ion imprinting approach has been used to develop a novel nanohybrid material for the selective separation of Cu2+ ions in aqueous solution. The Cu2+-imprinted polymer/ montmorillonite nanocomposite (IIP/Mt) and non-imprinted polymer/montmorillonite nanocomposite (NIP/Mt) were prepared by radical photopolymerization process in the visible light. Ion imprinting was indeed important as the recognition of copper ions by IIP/Mt was significantly superior to that of NIP/Mt that is the nanocomposite synthesized in the same way but in the absence of Cu2+ ions. The adsorption process as batch study was investigated under the experimental condition affecting same parameters such as contact time, concentration of ions metals and pH. The adsorption capacity of Cu2+ ions is maximized at pH 5. Removal of Cu2+ ion achieved equilibrium within 15 minutes; the results obtained were found to be fitted by the pseudo-second order kinetics model. The equilibrium process was well described by the Langmuir isothermal model and the maximum adsorption capacity was found to be 23.6 mg/g.


2019 ◽  
Vol 31 (3) ◽  
pp. 602-606
Author(s):  
Ch. Shanti Devi ◽  
S. Manimukta Devi ◽  
N. Shubhaschandra Singh

In this study, environmentally friendly hydrogels prepared from hydroxy propyl cellulose hydrogels blended with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) were employed to absorb selected metal ions of Cu and Fe to find potential applications in removal of metal ion from water or in wastewater treatment. Highest adsorption capacity of hydroxy propyl cellulose hydrogels blended with PVA or PVP is shown at 0.04 % (w/v) of the metal ion solutions. Hydroxy propyl cellulose hydrogel when blended PVA has shown greater adsorption of Fe(III) ion than Cu(II) ion at higher pH. Hydroxy propyl cellulose hydrogel when blended with PVP also showed maximum adsorption capacity rather than PVA blended hydrogel.


Author(s):  
Huiqing Lou ◽  
Siyu Li ◽  
Xiangwei Feng ◽  
Xianzhong Cao

Abstract Adsorptive properties for Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Zn(II) onto an amidoxime-functionalized polyacrylonitrile (APAN) micro/nanofibers were systematically investigated in hexahydroxy metallic solution system using batch experiments. The interactive effect of multi-metal ions in multi- metal systems was antagonistic in nature, and the adsorption capacity in multi-metal system was lower than that in single-metal system. The Langmuir isotherm model could explain respectively the isotherm and kinetic experimental data for hexahydroxy metallic system with much satisfaction. The maximum adsorption capacity in hexahydroxy metallic for Cd(II), Cr(III), Cu(II), Ni(II), Pb(II) and Zn(II) was calculated to be 98 mg/L, 158 mg/L, 80 mg/L, 76, 312 and 58 mg/L individually. The APAN micro/nanofibers possessed good selectivity toward Pb(II) and Cr(III), over Cd(II), Cu(II), Ni(II), and Zn(II), having the highest selectivity coefficients at 17.52 and 6.07 in the test range. The five adsorption-desorption cycle experiments exhibited that APAN micro/nanofibers adsorbent are readily reusable, and have potential for heavy metal removal from wastewater. The adsorption behavior in multi-metal systems was shown to be complex, including surface complexation, antagonistic competition and displacement reactions. The diversity and selectivity in metal ion adsorption onto the micro/nanofibers relate mainly to the stability constants, and the microscopic coupling mechanism between the heavy metal ions and the functional groups on the fiber surface. This interaction mechanism between the favorable component and other metal ions could contribute significantly to the direct displacement impact illustrated schematically.


2021 ◽  
Author(s):  
Yang Jiang ◽  
Bolin Tang ◽  
Pengfei Zhao ◽  
Man Xi ◽  
Yi Li

Abstract In this paper, methacrylic acid (MAA) and 4- vinyl pyridine (4-VP) as functional monomers, ethylene glycol two methyl acrylate (EGDMA) as crosslinking agent, isopropyl alcohol as the solvent, prepared the Cu(II)- and Pb(II)- imprinted polymers(IIPs) submicron spheres by precipitation polymerization. The presence/absence of the template ion in the preparation of the imprinted polymer was confirmed by EDX spectroscopy, and the structure of the particles was investigated using IR, SEM and BET analysis. From different components of crosslinker/monomer(C/M) ratio analysis, C/M at 1:3 was the optimal ratio for preparing IIPs. Atomic absorption spectroscopy (AAS) was characterized the imprinted polymers absorption behavior. The results show that the maximum adsorption capacity of Cu2+ and Pb2+ -imprinted polymer were 26.9mg﹒g−1 and 25.3mg﹒g−1, respectively. They also have good adsorption capacity and superior selectivity property for Cu2+ and Pb2+ in water, respectively. The selectivity factors (α) for Ni2+, Zn2+, Co2+ and Fe2+ were 16.5(Cu2+) and 12.1(Pb2+), 13.8(Cu2+) and 16.2(Pb2+), 10.8(Cu2+) and 10.1(Pb2+), 20.4(Cu2+) and 20.7(Pb2+), respectively. The regeneration experiment result demonstrates an excellent re-utilization property of these two type IIPs, after ten uses, the adsorption capacity can maintain above 60%.


2018 ◽  
Vol 15 (5) ◽  
pp. 306 ◽  
Author(s):  
Weifeng Liu ◽  
Lei Qin ◽  
Zhuolin An ◽  
Lin Chen ◽  
Xuguang Liu ◽  
...  

Environmental contextBecause of the multiple industrial applications of metals, contamination by metal ions is widespread and can at times endanger the environment and the health of human beings. We prepared ion-imprinted adsorbents to achieve selective recognition and smart separation of low-concentrations of copper ions from water. These smart imprinted materials have high potential for selective adsorption and removal of contaminant copper ions, particularly at very low concentrations. AbstractA temperature-responsive magnetic adsorbent (poly(N-propyl acrylamide) grafted magnetic carbon microspheres, Cu2+-IIP) was synthesised by ion imprinting technology for low concentration Cu2+ removal. Cu2+-IIP was prepared by using N-propyl acrylamide as a thermo-sensitive functional monomer, N,N-methylene-bis-acrylamide as a cross-linker and ammonium persulfate as an initiator. The morphologies and microstructures of samples were characterised by transmission electron microscopy, Fourier transform infrared spectrometry, thermogravimetry and vibrating sample magnetometry. Adsorption experiments were conducted in terms of kinetics, isotherms and selective recognition adsorption at low feed concentrations. Results indicate that Cu2+-IIP possesses good recognition selectivity and affinity for Cu2+, and can be separated from the treated solution quickly by applying an external magnetic field. The adsorption capacity towards Cu2+ depends on temperature and reaches a maximum value of 45.46 mg g−1 at 35 °C, higher than that of the non-imprinted polymer. The adsorption behaviour of Cu2+ on Cu2+-IIP can be well defined with both the pseudo-second-order kinetic model and Langmuir isotherm model. Cu2+-IIP performs good adsorption selectivity towards Cu2+ because the relative selectivity factors of Cu2+ with respect to Ni2+, Zn2+ and Cd2+ are 7.14, 7.60 and 6.77, respectively. The adsorption capacity of Cu2+-IIP remained 88.41 % after five cycles.


Author(s):  
Lang Wu ◽  
Zhengwei Luo ◽  
Hui Jiang ◽  
Zijian Zhao ◽  
Wenhua Geng

Abstract Fe3O4 nanoparticles-based magnetic Mo(VI) surface ion-imprinted polymer (Mo(VI)-MIIP) was elaborated employing 4-vinyl pyridine as a functional monomer. The adsorbent preparation was confirmed by Fourier-transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, X-ray diffraction, vibrating sample magnetometer, thermogravimetric analysis, and surface area analysis. Batch adsorption experiments displayed that the maximum adsorption capacity of Mo(VI)-MIIP was 296.40 mg g−1 at pH 3, while that of the magnetic non-imprinted polymer (MNIP) was only 147.10 mg g−1. The adsorption isotherm model was well-fitted by the Langmuir isotherm model. The adsorption experiments revealed that Mo(VI)-MIIP reached adsorption equilibrium within 30 min, and the kinetics data fitting showed that the pseudo-second-order kinetics model suitably described the adsorption process. Mo(VI)-MIIP exhibited an excellent adsorption selectivity to Mo(VI) in binary mixtures of Mo(VI)/Cr(VI), Mo(VI)/Cu(II), Mo(VI)/H2PO44-, Mo(VI)/Zn(II), and Mo(VI)/I–, with relative selectivity coefficients toward MNIP of 13.71, 30.27, 20.01, 23.53, and 15.89, respectively. After six consecutive adsorption-desorption cycles, the adsorption capacity of Mo(VI)-MIIP decreased by 9.5% (from 228.4 mg g−1 to 206.7 mg g−1 at initial Mo(VI) concentration of 250 mg L−1), demonstrating its reusability.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 63
Author(s):  
Maria Harja ◽  
Gabriela Buema ◽  
Nicoleta Lupu ◽  
Horia Chiriac ◽  
Dumitru Daniel Herea ◽  
...  

Fly ash/magnetite material was used for the adsorption of copper ions from synthetic wastewater. The obtained material was characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area, and vibrating sample magnetometer (VSM). Batch adsorption experiments were employed in order to investigate the effects of adsorbent dose, initial Cu (II) concentration and contact time over adsorption efficiency. The experimental isotherms were modeled using Langmuir (four types of its linearization), Freundlich, Temkin, and Harkins–Jura isotherm models. The fits of the results are estimated according to the Langmuir isotherm, with a maximum adsorption capacity of 17.39 mg/g. The pseudo-second-order model was able to describe kinetic results. The data obtained throughout the study prove that this novel material represents a potential low-cost adsorbent for copper adsorption with improved adsorption capacity and magnetic separation capability compared with raw fly ash.


Sign in / Sign up

Export Citation Format

Share Document