Ion imprinted polymer particles of neodymium:synthesis,characterization and selective recognition

Neodymium ion imprinted polymer（Nd^3＋-IIP） particles for selective solid-phase extraction of Nd^3＋ were prepared and determined with inductively coupled plasma atomic emission spectrometry（ICP-AES）.The unleached Nd^3＋-IIP particles were prepared by the copoly-merization of Nd^3＋-5,7-dichloroquinoline-8-ol-4-vinylpyridine ternary complex with styrene and divinyl benzene, then Nd^3＋ was leached to obtain Nd^3＋-IIP particles.The adsorption capacity of the Nd3＋-IIP was 35.18 mg/g.The largest selectivity coefficient for Nd3＋ in the presence of competitive ions such as La^3＋, Ce^3＋, Pr^3＋ and Sm^3＋ was over 110.The proposed method was validated by analyzing two certified reference materials（GBW07301a sediment and GBW07401 soil） and the determined values were in a good agreement with standard values.The method was convenient, selective, sensitive and applicable to the determination of trace Nd^3＋ in environmental samples with complicated matrix.

Sensitivity Enhancement in Uranium Determination by UV-Visible Spectroscopy Using Ion Imprinted Polymer

There is need to determination of uranium concentration at ppb level in environmental matrices.Due to low sensitivity of FAAS,UV-Visible Spectroscopy is generally used as measurement technique.In this study,ion-imprinted polymers(IIP)were prepared for uranyl ion(imprint ion)by formation of ternary(salicylaldoxime and 4-vinylpyridine)complex in 2-methoxy ethanol(porogen)following copolymerization with methacrylic acid(MAA)as a functional monomer and ethylene glycol dimethacrylate(EGDMA)as crosslinking monomer using 2,2-azobisisobutyronitrile as initiator.The synthesized polymers were characterized by FTIR and TGA analysis.ArsenazoⅢin 3M HClO_4 was used as complexing agent in the measurement step.The optimal pH for preconcentration was found to be between 3.5~6.5values.The developed method was applied to uranium(Ⅵ)determination in natural water samples.

Selective adsorption behavior of ion-imprinted magnetic chitosan beads for removal of Cu(Ⅱ) ions from aqueous solution

Heavy metal ion is one of the major environmental pollutants.In this study,a Cu(Ⅱ)ions imprinted magnetic chitosan beads are prepared to use chitosan as functional monomer,Cu(Ⅱ)ions as template,Fe_(3)O_(4) as magnetic core and epichlorohydrin and glutaraldehyde as crosslinker,which can be used for removal Cu(Ⅱ)ions from wastewater.The kinetic study shows that the adsorption process follows the pseudosecond-order kinetic equations.The adsorption isotherm study shows that the Langmuir isotherm equation best fits for the monolayer adsorption processes.The selective adsorption properties are performed in Cu(Ⅱ)/Zn(Ⅱ),Cu(Ⅱ)/Ni(Ⅱ),and Cu(Ⅱ)/Co(Ⅱ)binary systems.The results shows that the ⅡMCD has a high selectivity for Cu(Ⅱ)ions in binary systems.The mechanism of ⅡMCD recognition Cu(Ⅱ)ions is also discussed.The results show that the ⅡMCD adsorption Cu(Ⅱ)ions is an enthalpy controlled process.The absolute value of DH(Cu(Ⅱ))and DS(Cu(Ⅱ))is greater than DH(Zn(Ⅱ),Ni(Ⅱ),Co(Ⅱ))and DS(Zn(Ⅱ),Ni(Ⅱ),Co(Ⅱ)),respectively,this indicates that the Cu(Ⅱ)ions have a good spatial matching with imprinted holes on ⅡMCD.The FTIR and XPS also demonstrates the strongly combination of function groups on imprinted holes in the suitable space position.Finally,the ⅡMCD can be regenerated and reused for 10 times without a significantly decreasing in adsorption capacity.This information can be used for further application in the selective removal of Cu(Ⅱ)ions from industrial wastewater.

Ion imprinted cryogel-based supermacroporous traps for selective separation of cerium(Ⅲ) in real samples

This study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce（Ⅲ） ions in aqueous solutions and bastnasite ore samples.2-Hydroxyethyl methacrylate（HEMA） and N-methacryloylamido antipyrine（MAAP） were used as functional monomers for the preparation of Ce（Ⅲ） imprinted cryogel. The effects of various factors such as initial Ce（Ⅲ） concentration, flow rate, pH, interaction time and ionic strength on the Ce（Ⅲ） binding to the prepared ion imprinted cryogels were also studied. The binding equilibrium for Ce（Ⅲ） is obtained in30 min at the flow rate of 0.5 mL/min. The maximum binding capacity of the prepared ion imprinted cryogel towards Ce（Ⅲ） is obtained as 36.58 mg/g at optimum conditions. The selectivity of the prepared ion imprinted cryogel towards Ce（Ⅲ） in the presence of other possible interfering lanthanide ions such as La（Ⅲ） and Nd（Ⅲ） were also performed. The obtained results showed that the prepared ion imprinted cryogel exhibits high selectivity and sensitivity towards Ce（Ⅲ） ions. The limit of detection（LOD） was found as 50 μg/L.

AN IMPRINTED POLYMER FOR REMOVAL OF Cd^(2+) FROM WATER SAMPLES:OPTIMIZATION OF ADSORPTION AND RECOVERY STEPS BY EXPERIMENTAL DESIGN

A new ion-imprinted polymer （liP） was synthesized by copolymerization of 4-vinylpyridine （monomer）, ethyleneglycoldimethacrylate （cross-linker） and 2,2-azobis-isobutyronitrile （initiator） in the presence of Cd2＋ and quinaldic acid （complexing agent）. It was found that the adsorption capacity of IIP and blank polymer were 45.0 and 6.2 mg g-l, respectively. The relative selectivity coefficients of the imprinted polymer for different binary mixture were also calculated. Compared to non-imprinted polymer （NIP）, the IIP had higher selectivity for Cd（II）. The IIP was used as a sorbent for cadmium extraction from water samples by using a simple batch extraction procedure. The effect of different parameters on Cd2＋ extraction and its recovery from the IIP were evaluated and optimized by using experimental design methodology. The optimized adsorption/desorption procedure was applied for cadmium removal from the real water samples. The obtained recoveries proved that this IIP could be used for removal of trace cadmium ions from water samples.

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

A novel surface ion implinted 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）.

Electrochemical Sensor for Sensitive Determination of Ga（III） Ion Based on β-Cyclodextrin Incorporated Multi-walled Carbon Nanotubes and Imprinted Sol-gel Composite Film

A novel sensor for detection of trace gallium ion [Ga（III）] was created by stepwise modification of a gold electrode with fl-cyclodextrin （β-CD）/multi-walled carbon nanotubes （MWCNTs） and an ion imprinted polymer （IIP）. The sensor surface morphology was characterized by scanning electron microscopy. The electrochemical performance of the imprinted sensor was investigated by cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The sensor displayed excellent selectivity towards the target Ga（III） ion. Meanwhile, the introduced MWCNTs displayed noticeable catalytic activity, and fl：CD demonstrated significant enrichment capacity. A linear calibration curve was obtained covering the concentration range from 5.0 × 10 8 to 1.0 × 10-4 moloL-1, with a detection limit of 7.6× 10 9 mol·L-1. The proposed sensor was successfully applied to detect Ga（III） in real urine samples.