Immobilization of Pycnoporus sanguineus laccase by metal affinity adsorption on magnetic chelator particles

BACKGROUND: Immobilized enzymes provide many advantages over free enzymes including repeated or continuous reuse, easy separation of the product from reaction media, easy recovery of the enzyme, and improvement in enzyme stability. In order to improve catalytic activity of laccase and increase its industrial application, there is great interest in developing novel technologies on laccase immobilization. RESULTS: Magnetic Cu²⁺‐chelated particles, prepared by cerium‐initiated graft polymerization of tentacle‐type polymer chains with iminodiacetic acid (IDA) as chelating ligand, were employed for Pycnoporus sanguineus laccase immobilization. The particles showed an obvious high adsorption capacity of laccase (94.1 mg g^?1 support) with an activity recovery of 68.0% after immobilization. The laccase exhibited improved stability in reaction conditions over a broad temperature range between 45 °C and 70 °C and an optimal pH value of 3.0 after being adsorbed on the magnetic metal‐chelated particles. The value of the Michaelis constant (K_m) of the immobilized laccase (1.597 mmol L^?1) was higher than that of the free one (0.761 mmol L^?1), whereas the maximum velocity (V_max) was lower for the adsorbed laccase. Storage stability and temperature endurance of the immobilized laccase were found to increase greatly, and the immobilized laccase retained 87.8% of its initial activity after 10 successive batch reactions. CONCLUSION: The immobilized laccase not only can be operated magnetically, but also exhibits remarkably improved catalytic capacity and stability properties for various parameters, such as pH, temperature, reuse, and storage time, which can provide economic advantages for large‐scale biotechnological applications of laccase. Copyright © 2007 Society of Chemical Industry     

Cu(II)‐incorporated,histidine‐containing,magnetic‐metal‐complexing beads as specific sorbents for the metal chelate affinity of albumin

N‐Methacryloyl‐(L )‐histidine methyl ester (MAH) was synthesized from metharyloyl chloride and histidine. Spherical beads with an average size of 150–250 μm were obtained by the suspension polymerization of ethylene glycol dimethacrylate and MAH in an aqueous dispersion medium. Magnetic poly(ethylene glycol dimethacrylate‐co‐N‐Methacryloyl‐(L )‐histidine methyl ester) [m‐p(EGDMA‐co‐MAH)] microbeads were characterized with swelling tests, electron spin resonance, elemental analysis, and scanning electron microscopy. The specific surface area of the beads was 80.1 m²/g. m‐p(EGDMA‐co‐MAH) microbeads with a swelling ratio of 40.2% and 43.9 μmol of MAH/g were used for the adsorption of bovine serum albumin (BSA) in a batch system. The Cu(II) concentration was 4.1 μmol/g. The adsorption capacity of BSA on the Cu(II)‐incorporated beads was 19.2 mg of BSA/g. The BSA adsorption first increased with the BSA concentration and then reached a plateau, which was about 19.2 mg of BSA/g. The maximum adsorption was observed at pH 5.0, which was the isoelectric point of BSA. The BSA adsorption increased with decreasing temperature, and the maximum adsorption was achieved at 4°C. High desorption ratios (>90% of the adsorbed BSA) were achieved with 1.0M NaSCN (pH 8.0) in 30 min. The nonspecific adsorption of BSA onto the m‐p(EGDMA‐co‐MAH) beads was negligible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2669–2677, 2004     

Porous dye affinity beads for albumin separation from human plasma

Porous polymeric beads were obtained by the suspension polymerization of 2‐hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA). Poly(HEMA–EGDMA) beads were characterized by surfacearea measurements, swelling studies, FTIR, scanning electron microscopy (SEM), and elemental analysis. Poly (HEMA–EGDMA) beads had a specific surface area of 56 m²/g. SEM observations showed that the poly(HEMA–EGDMA) beads abounded macropores. Poly(HEMA–EGDMA) beads with a swelling ratio of 55%, and containing different amounts of Reactive Red 120 (9.2–39.8 μmol/g) were used in the adsorption/desorption of human serum albumin (HSA) from aqueous solutions and human plasma. The nonspecific adsorption of HSA was very low (0.2 mg/g). The maximum HSA adsorption amount from aqueous solution in phosphate buffer was 60.1 mg/g at pH 5.0. Higher HSA adsorption value was obtained from human plasma (up to 95.7 mg/g) with a purity of 88%. The equilibrium monolayer adsorption amount, Q_max was determined as 172.4 mg/g. The dimensionless separation factor (R_L) value shows that the adsorption behavior of HSA onto the Reactive Red 120 attached poly(HEMA–EGDMA) beads was favorable (0 < R_L < 1). Desorption of HSA from Reactive Red 120 attached poly (HEMA–EGDMA) beads was performed using 0.1M Tris/HCl buffer containing 0.5M NaCl. It was observed that HSA could be repeatedly adsorbed and desorbed with Reactive Red 120‐attached poly(HEMA–EGDMA) beads without significant loss in the adsorption amount. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Immobilized metal ions cellophane–PGMA‐grafted membranes for affinity separation of β‐galactosidase enzyme. I. Preparation and characterization

Immobilized Cu²⁺ ions affinity cellophane–poly(glycidyl methacrylate) (PGMA)‐grafted membranes have been prepared through three steps. The first step was introducing of epoxy groups to its chemical structure through grafting process with PGMA. Factors affecting the grafting process have been studied and grafting percentage (GP) up to 233% has been obtained. The second step was converting the introduced epoxy groups to sulfonic ones. It was found that maximum amount of sulfonic groups (2.7 mmol/g) was obtained with minimum GP (46.08%). The third and last step was the immobilization of Cu²⁺ ions into sulfonated grafted membranes obtained from the previous step. Maximum amount of immobilized Cu²⁺ ions was found to be 60.9 ppm per gram of polymer. The verification of the grafting and sulfonation steps has been performed through characterization of the obtained membranes using FTIR, TGA, and EDAX analysis. Finally, Cu²⁺‐immobilized membranes have been evaluated in separation of β‐galactosidase (β‐Gal) enzyme from its mixture with bovine serum albumin (BSA) in different pH medium. Maximum protein adsorption, for both proteins, has been obtained at pH range 4–4.5; as 90 and 45% for β‐Gal and BSA, respectively. The results showed high affinity toward β‐Gal separation although BSA concentration (0.5%) is 20‐folds of β‐Gal (0.025%). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Concanavalin A immobilized magnetic poly(glycidyl methacrylate) beads for antibody purification

Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads in monosize and spherical for (1.62 μm in diameter) were used for the purification of human immunoglobulin G (IgG) from human plasma. Con A was immobilized by covalent binding onto the mPGMA beads. The maximum IgG adsorption on the mPGMA-Con A beads was observed at pH 6.0. The nonspecific IgG adsorption onto the plain mPGMA beads was very low (0.22 mg/g). Scatchard analysis of the adsorption isotherm for IgG on mPGMA-Con A beads showed an affinity constant (K_a) of 1.39 × 10⁵ M⁻¹ and a theoretical maximum adsorption capacity of 109.1 mg/g. An apparent IgG adsorption capacity of 66.2 mg/g was observed under the experimental conditions. IgG adsorption capacity from human plasma was observed as 48.0 mg/g. The adsorption of human serum albumin from plasma was 2.0 mg/g. The total protein adsorption was determined to be 50.0 mg/g. IgG molecules could be repeatedly adsorbed and eluted with the mPGMA-Con A beads without noticeable loss in the IgG adsorption capacity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation and adsorption behavior of a cellulose‐based,mixed‐mode adsorbent with a benzylamine ligand for expanded bed applications

A novel mixed‐mode expanded bed adsorbent with anion‐exchange properties was explored with benzylamine as the functional ligand. The cellulose composite matrix, densified with stainless steel powder, was prepared with the method of water‐in‐oil suspension thermal regeneration. High activation levels of the cellulose matrix were obtained with allyl bromide because of the relative inertness of the allyl group under the conditions of the activation reaction. After the formation of the bromohydrin with N‐bromosuccinimide and coupling with benzylamine, the activated matrix was derived to function as a mixed‐mode adsorbent containing both hydrophobic and ionic groups. The protein adsorption capacity was investigated with bovine serum albumin as a model protein. The results indicated that the prepared adsorbent could bind bovine serum albumin with a high adsorption capacity, and it showed salt tolerance. Effective desorption was achieved by a pH adjustment across the isoelectric point of the protein. The interactions between the cell and adsorbent were studied, and the bioadhesion was shielded by the adjustment of the salt concentration above 0.1M. Stable fluidization in the expanded bed was obtained even in a 2% (dry weight) yeast suspension. The direct capture of target proteins from a biomass‐containing feedstock without extra dilution steps could be expected with the mixed‐mode adsorbent prepared in this work, and this would be especially appropriate for expanded bed adsorption applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Gas-assisted low-field magnetic separation for large scale continuous magnetic bio-separation process

In this study, the gas-assisted low-field magnetic separation (GAMS) was proposed for continuous large-scale magnetic bio-separation process. Magnetic recovery processes in selective separation of binary mixed proteins by magnetic microspheres were selected as a model. Basing on magnetic recovery efficiency of the batch GAMS for this model, the continuous GAMS with an amplifying small pilot scale was further researched. The continuous throughput of GAMS for adsorption, washing, and desorption step reached 12 L/h, 12 L/h, and 18 L/h with an adsorbent recovery above 95%, respectively. Furthermore, magnetic particles via the top magnetic roller could be well-separated from free proteins with good floatability via the bottom outlet of flotation column, and bubbling operation did not cause the significant denaturation of target protein. Compared with classic high gradient magnetic separation, GAMS had the advantages of easy scale-up, easy continuous operation, and low-cost, showing great potential for large-scale magnetic bio-separation process. © 2018 American Institute of Chemical Engineers AIChE J, 65: 175–183, 2019     

Development of environmentally responsive hydrogels with metal affinity behavior

This work describes initial efforts to incorporate affinity ligands within an environmentally responsive hydrogel. Metal affinity ligands were chosen as model affinity groups and thermally responsive N‐isopropyl acrylamide/acrylamide copolymers were used as the base hydrogels. The ? NH₂ group of the acrylamide serves as a reactive group for functionalization with metal affinity ligands. The gels were synthesized by free radical polymerization and Cu²⁺ was bound to the gel via 1,4‐butanediol diglycidyl ether (BDE) as a linker and iminodiacetic acid (IDA) as a chelating ligand. The base acrylamide gels were also functionalized with metal affinity ligands to allow for comparison with thermally responsive affinity gels. The results show the effectiveness of this technique for both these types of gels, and an improved method to immobilize metal affinity groups on to thermally sensitive N‐isopropyl acrylamide gels was also developed. It was seen that the yields for the reaction with BDE decreased with increased reaction time in both kinds of gels, whereas reaction with IDA showed a decrease in yields with increase in temperature for N‐isoporpyl acrylamide gels and increase in yields for acrylamide gels. Further techniques were developed to overcome diffusional resistances and stresses in the thermally responsive N‐isopropyl acrylamide gels so as to improve the distribution of Cu²⁺ ions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Antibody purification by concanavalin A affinity chromatography

Concanavalin A (Con A) immobilized poly(2‐hydroxyethyl methacrylate) (PHEMA) beads in a spherical form (100–150 μm in diameter) were used for the affinity chromatography purification of human immunoglobulin G (IgG) from aqueous solutions and human plasma. PHEMA adsorbents were prepared by suspension polymerization. Bioligand Con A was then immobilized by covalent binding onto PHEMA beads. The maximum IgG adsorption on the PHEMA/Con A beads was observed at pH 6.0. The nonspecific IgG adsorption onto the plain PHEMA adsorbents was very low (ca. 0.17 mg/g). Higher adsorption values (up to 54.3 mg/g) were obtained when the PHEMA/Con A beads were used from aqueous solutions. A higher adsorption capacity was observed for human plasma (up to 69.4 mg/g) with a purity of 82.5%. The adsorption capacities of other blood proteins were 2.0 mg/g for fibrinogen and 4.2 mg/g for albumin. The total protein adsorption was determined to be 76.0 mg/g. IgG molecules could be repeatedly adsorbed and desorbed with the PHEMA/Con A beads without noticeable loss in the IgG adsorption capacity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1202–1208, 2005     

Preparation and characterization of micron‐sized non‐porous magnetic polymer microspheres with immobilized metal affinity ligands by modified suspension polymerization

A novel preparation method of micron‐sized non‐porous magnetic polymer microspheres with immobilized metal affinity ligands was developed. A modified suspension polymerization of methacrylate (MA) and divinylbenzene (DVB) was performed in the presence of oleic acid‐coated magnetic Fe₃O₄ nanoparticles to obtain magnetic poly (methacrylate‐divinylbenzene) (mPMA‐DVB) microspheres. Through ammonolysis using ethylenediamine (EDA) and subsequent carboxymethylation with chloroacetic acid, magnetic polymer microspheres with chelate ligands of iminodiacetic acid (IDA) were obtained. Charging with copper ions resulted in magnetic polymer microspheres capable of binding proteins that display metal affinity. The morphology, magnetic properties, and composition of magnetic polymer microspheres were characterized with scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and Fourier transform infrared spectroscopy (FTIR), respectively. Bovine hemoglobin (BHb) was adopted as a model protein to investigate their affinity adsorption capacity. It was found that the adsorption capacity was as high as 168.2 mg/g microspheres and with rather low non‐specific adsorption. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2174–2180, 2005     

A magnetic mesoporous chitosan based core‐shells biopolymer for anionic dye adsorption: Kinetic and isothermal study and application of ANN

In this study, Chitosan/Al₂O₃/Fe₃O₄ core‐shell composite microsphere (CAMF) was used as an effective sorbent with high adsorption capacity for the removal of anionic azo dye model from aqueous solution. The obtained composite was characterized by XRD, SEM, EDX, and BET analysis. The results showed the high methyl orange (MO) adsorption in a wide pH range of 4–10 and the optimum adsorbent dosage was obtained 0.6 g L^?1. It is indicated that the equilibrium data followed the Langmuir isotherm model and the adsorption kinetic was well fitted with pseudo‐second‐order kinetic model. Also, the adsorption kinetic was controlled by the film diffusion and intra‐particle diffusion, simultaneously. It is revealed that by increasing the particle size from <0.1 μm to ～0.4 μm, the adsorption capacity did not change, significantly. The adsorption capacity of MO on CAMF was predicted by multilayer perceptron (MLP) neural network at different initial MO concentration, in which the predictions of MLP model had very good agreement with experimental data. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43466.     

Preparation and characterization of hyperbranched polyester capillary columns used for the separation of basic proteins

A series of hyperbranched polyesters with pentaerythritol as the core were synthesized and coated on the inner surface of fused‐silica capillaries by chemical bonding. Three kinds of basic proteins were selected for studying the behavior of the adsorption to fused‐silica capillaries. Comparative studies of the coating materials were conducted, and the experimental results showed that the coated columns with hyperbranched polyesters could suppress the electroosmotic flow greatly and effectively prevent adsorption in the pH range of 4–6; they were superior to capillaries coated with traditional hydroxypropyl cellulose. Furthermore, research was conducted to study the effect of hyperbranched polyester generation on the column efficiency. The results showed that higher column efficiency was obtained on a capillary column coated with the sixth generation of the hyperbranched polyester at pH 5.0. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of micrometer‐sized,monodisperse, magnetic polymer particles

Micrometer‐sized, monodisperse, magnetic composite particles were prepared by heating micrometer‐sized, monodisperse, hollow polystyrene/polydivinylbenzene composite polymer particles at 200°C for 4 h (particles had been dipped in pentacarbonyliron) and then washed in 12 N HCl and water. The hollow polymer particles were produced by seeded polymerization by the dynamic swelling method that was proposed by authors. The magnetic composite particles contained Fe₃O₄, the content of which was 49% based on total weight, and were attracted easily in water by a 1650 G magnet. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 428–433, 2003     

Pebax–polydopamine microsphere mixed‐matrix membranes for efficient CO2 separation

Novel facilitated‐transport mixed‐matrix membrane (MMM) were prepared through the incorporation of polydopamine (PDA) microspheres into a poly(amide‐b‐ethylene oxide) (Pebax MH 1657) matrix to separate CO₂–CH₄ gas mixtures. The Pebax–PDA microsphere MMMs were characterized by Fourier transform infrared spectroscopy, scanning electron microcopy, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis. The PDA microspheres acted as an adhesive filler and generated strong interfacial interactions with the polymer matrix; this generated a polymer chain rigidification region near the polymer–filler interface. Polymer chain rigidification usually results in a larger resistance to the transport of gas with a larger molecular diameter and a higher CO₂–CH₄ selectivity. In addition, the surface of PDA microspheres contained larger numbers of amine, imine, and catechol groups; these were beneficial to the improvement of the CO₂ separation performance. Compared with the pristine Pebax membrane, the MMM with a 5 wt % PDA microsphere loading displayed a higher gas permeability and selectivity; their CO₂ permeability and CO₂–CH₄ selectivity were increased by 61 and 60%, respectively, and surpassed the 2008 Robeson upper bound line. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44564.     

Reusable magnetic nanocluster coated with poly(acrylic acid) and its adsorption with an antibody and an antigen

The synthesis of negatively charged magnetite nanoclusters grafted with poly(acrylic acid) (PAA) and their application as reusable nanosupports for adsorption with antibodies and antigens are presented in this article. They were facilely prepared via the free‐radical polymerization of PAA in the presence of functionalized magnetite nanoparticles to obtain highly negative charged nanoclusters with a high magnetic responsiveness and good dispersibility and stability in water. According to transmission electron microscopy, the sizes of the nanoclusters ranged between 200 and 500 nm, without large aggregation visually observed in water. The hydrodynamic size of the nanocluster consistently increased with increasing pH of the dispersion; this indicated its pH‐responsive properties, which was due to the repulsion of the anionic carboxylate groups in the structure. This nanocluster was successfully used as an efficient and reusable support for adsorption with anti–horseradish peroxidase antibody. It preserved higher than a 97% adsorption ability of the antibody after eight reuse cycles; this signified the potential of this novel nanocluster as a reusable support in the magnetic separation applications of other bioentities. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46160.     

The preparation of SPEEK/phosphate salts membranes and application for CO2/CH4 separation

SPEEK/phosphate salts membranes were prepared and utilized for CO₂/CH₄ separation. SPEEK with abundant –SO₃H groups and EO groups on polymer chains would be beneficial for CO₂ transport. The doped phosphate salts (NaH₂PO₄, Na₂HPO₄ and Na₃PO₄) with different acid‐base properties increased the water content in the membrane, and water was expected to increase both the solubility and diffusivity of CO₂ in the membrane. All membranes were characterized by FTIR, TGA, and XRD. The CO₂ permeability and CO₂/CH₄ selectivity of SPEEK/Na₃PO₄ membranes were higher than that of SPEEK/NaH₂PO₄ and SPEEK/Na₂HPO₄ membranes. Compared to the pure SPEEK membrane, the CO₂ permeability and CO₂/CH₄ selectivity of SPEEK/Na₃PO₄?10 membrane were increased by 144% and 65%, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43399.     

Simultaneous depletion of albumin and immunoglobulin G by using twin affinity magnetic nanotraps

For biomarker discovery, simultaneous removal of albumin and immunoglobulin G (IgG) become more important for both concentrating other species including potential biomarkers and getting rid of their masking effect. In this study, we have proposed a covalent and photosensitive cross-linking conjugation of the biomolecules on nanostructures for the depletion of target proteins from aqueous solution and serum. The effect of concentration, pH, temperature and ionic strength on the adsorption of twin affinity nanotraps based on Cibacron Blue F3GA and Protein A were investigated. The efficiency of albumin and IgG depletion from human serum was performed using sodium dodecylsulfate–polyacrylamide gel electrophoresis.     

磁性催化剂反应器耦合磁分离装置

反应磁分离耦合装置兼具化学反应和流固相分离的功能,有助于提高反应效率、降低分离能耗、缩短工艺流程和避免催化剂磨损流失。综述近年来反应磁分离耦合装置的研究进展,流化态耦合磁分离装置包括磁稳流化床反应器和流化床耦合旋流磁分离装置,悬浮态耦合磁分离装置包括磁分离耦合悬浮态光催化反应器和釜式反应器耦合磁分离装置。指出磁性催化剂反应器和磁分离耦合装置应用中需要解决的关键问题是:规范生产适用于磁性催化剂反应器耦合磁分离装置的磁性催化剂以及构建磁性催化剂反应器耦合磁分离装置过程中必须引入磁场发生器。     

Influence of support layer and PDMS coating conditions on composite membrane performance for ethanol/water separation by pervaporation

A systematic study was performed on the combination of support properties and polydimethylsiloxane (PDMS) coating conditions for the lab‐scale preparation of a defect‐free, thin film composite membrane for organophilic pervaporation. Support layers having comparable surface porosities were prepared from three polymers with different chemical composition (PVDF, PSF, PI). Their exact role on the deposition of the PDMS coating (i.e., wetting and intrusion) and the final membrane performance (i.e., effect on mass transfer of the permeants) was studied. The crosslinking behavior of dilute PDMS solutions was studied by viscosity measurements to optimize the coating layer thickness, support intrusion and wetting. It was found essential to pre‐crosslink the PDMS solution for a certain time prior to the coating. Dip time for coating the PDMS solution on the supports was varied by using automated dip coating machine. The performance of the synthesized membranes was tested in the separation of ethanol/water mixtures by pervaporation. Both flux and selectivity of the membranes were clearly influenced by the support layer. Resistance of the support layers increased by increasing the polymer concentration in the casting solutions of the supports. Increasing the dip time of the PDMS coating solution led to increased selectivity of the composite membranes. Scanning Electron Microscopy analysis of the composite membranes showed that this leads to a minor increase in the thickness of the PDMS top layer. Top layer thickness increased linearly with the square root of the dip time (t^0.5) at a constant withdrawal speed of the support. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43670.     

Porous dye affinity beads for nickel adsorption from aqueous solutions: A kinetic study

We investigated a new adsorbent system, Reactive Red 120 attached poly(2‐hydroxyethyl methacrylate ethylene dimethacrylate) [poly(HEMA–EDMA)] beads, for the removal of Ni²⁺ ions from aqueous solutions. Poly(HEMA–EDMA) beads were prepared by the modified suspension copolymerization of 2‐hydroxyethyl methacrylate and ethylene dimethacrylate. Reactive Red 120 molecules were covalently attached to the beads. The beads (150–250 μm), having a swelling ratio of 55% and carrying 25.5 μmol of Reactive Red 120/g of polymer, were used in the removal of Ni²⁺ ions. The adsorption rate and capacity of the Reactive Red 120 attached poly(HEMA–EDMA) beads for Ni²⁺ ions was investigated in aqueous media containing different amounts of Ni²⁺ ions (5–35 mg/L) and having different pH values (2.0–7.0). Very high adsorption rates were observed at the beginning, and adsorption equilibria were then gradually achieved in about 60 min. The maximum adsorption of Ni²⁺ ions onto the Reactive Red 120 attached poly(HEMA–EDMA) beads was 2.83 mg/g at pH 6.0. The nonspecific adsorption of Ni²⁺ ions onto poly(HEMA–EDMA) beads was negligible (0.1 mg/g). The desorption of Ni²⁺ ions was studied with 0.1M HNO₃. High desorption ratios (>90%) were achieved. The intraparticle diffusion rate constants at various temperatures were calculated as k_20°C = 0.565 mg/g min^0.5, k_30°C = 0.560 mg/g min^0.5, and k_40°C = 0.385 mg/g min^0.5. Adsorption–desorption cycles showed the feasibility of repeated use of this novel adsorbent system. The equilibrium data fitted very well both Langmuir and Freundlich adsorption models. The pseudo‐first‐order kinetic model was used to describe the kinetic data. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:5056–5065, 2006