Magnetic Cellulose Research Articles

Preparation and characterization of magnetic cellulose fibers modified with cobalt ferrite nanoparticles

Magnetic fibers were prepared by lumen loading method using bleached eucalyptus fibers as cellulose source and cobalt ferrite nanoparticles (CoFe2O4). For this, CoFe2O4 nanoparticles were first synthesized by the chemical co-precipitation method and then incorporated into eucalyptus fibers using polyethylenimine (PEI) as retention-aid. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM-EDS), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) for magnetic properties. The obtained nanoparticles showed an inverse cubic spinel crystalline structure with an average size of 9 nm, exhibiting further a ferrimagnetic behavior. It was observed in the SEM images the deposition of nanoparticles on surface and into macropores of fibers. The results indicate a maximum saturation magnetization of ∼8 emu/g for the modified fibers. Besides, through an experimental design, it was established that loading degree and magnetic response of modified fibers are affected by both dose of nanoparticles and agitation time used in the modification process.

Novel magnetic pillar[5]arene polymer as adsorbent for rapid removal of organic pollutants in water or air

A magnetic pillar[5]arene polymer (M-P5A-P) was prepared for removal of organic pollutants in water and air. M-P5A-P was synthesized by grafting pillar[5]arene polymer on the surface of the cellulose-closed magnetic microparticles. The obtained M-P5A-P was characterized by FT-IR spectroscopy, transmission electron microscope, X-ray diffraction, magnetic hystersis loop analysis, thermo-gravimetric analysis, and energy dispersive X-ray spectrometer. When used as an adsorbent for four different types of organic pollutants (bisphenol A, 1-naphthylamine, propranolol and methylene blue) in water, M-P5A-P presented much higher adsorption ability than magnetic cellulose and fast binding kinetics with the equilibrium time all less than 10 min. Moreover, M-P5A-P can be rapidly separated from solution by a magnet, and it showed good reusability and reproducibility. M-P5A-P was successfully applied to the simultaneously rapid removal of four pollutants (0.1 μg mL−1 for each one) in mixed solution with removal efficiencies of 82.3–99.4% within 5 min. M-P5A-P can also rapidly capture styrene vapor at environmental concentration to a concentration much lower than the limit of the U.S. Occupational Safety and Health Administration within 5 min. Therefore, M-P5A-P can be potentially used as a good adsorbent for simultaneously removing different type of organic pollutants in water or air.

Characterization and antibacterial effect of quaternized chitosan anchored cellulose beads

Some thermoduric food spoilage bacteria pose great threat to beverage industry. To tackle the challenge, hydroxypropyl trimethyl ammonium chloride chitosan (HTCC) grafted magnetic cellulose beads have been prepared via a dropping technology. Sodium periodate oxidation process was carried out to form dialdehyde functional groups on the regenerated cellulose beads mixed with maghemite nanoparticles. HTCC was anchored on the beads through Schiff base reaction. The structure and properties of HTCC anchored beads were evaluated by Fourier transform infrared (FTIR) spectra, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Thermal stability of the beads was estimated by thermogravimetric analysis (TGA) and differential thermal gravity (DTG), and the decomposition temperature of the beads were around 200–300 °C. A long-term antibacterial activities of the beads against Alicyclobacillus acidoterrestris were confirmed caused by the covalent bond between HTCC and the beads. The biodegradable HTCC grafted cellulose beads may provide a novel approach for food safety management.

Magnetizing Cellulose Fibers with CoFe2O4 Nanoparticles for Smart Wound Dressing for Healing Monitoring Capability.

In an attempt to address issues accompanying the unnecessary change of wound dressings of patients in traditional wound care management, we are developing smart wound dressing material, based on magnetic nanosensors, for wireless monitoring of the wound healing process. The technology is based on magnetizing the cellulose component of the dressing and tuning the resulting magnetic cellulose to respond to temperature changes of the wound. Here, we report the development of the magnetic cellulose through grafting of magnetic CoFe2O4 nanoparticles (CoFe2O4 NPs) onto cellulose fibers using a layer-by-layer method. Three different methods were used for the synthesis, but the CoFe2O4 NPs with superior properties were obtained through hydrothermal autoclaving followed by annealing. They had 98% match to the XRD reference pattern and rod-like shape (agglomerating into nanowires), with diameter between 30 and 50 nm and length ranging from 582 nm to 5.42 μm and magnetization and demagnetization values of 84.5 emu g-1 and -84.5 emu g-1, respectively. Upon grafting the CoFe2O4 NP onto fibers, the cellulose became magnetic, with magnetization values dependent on the initial concentration of the CoFe2O4 NP in the grafting media. Computational investigation revealed that the CoFe2O4 NPs are covalently bonded onto the cellulose fiber through the formation of -Co-O-C- bonding. In brief, the current findings advanced the development of a wireless wound-healing monitoring technology based on integration of sensory ferrimagnet CoFe2O4 NPs into cellulose fibers of wound dressings.

Preparation, characterization and long-term antibacterial activity of nisin anchored magnetic cellulose beads

Along with the concerns for food safety and environment, the demand of cost-effective and biodegradable materials in food treatment is increasing. In order to solve the problem of certain spoilage microorganisms, nisin anchored cellulose beads were prepared by a sol–gel transition method. By mixing γ-Fe2O3 nanoparticles with cellulose in 8% LiOH·H2O/15% urea aqueous solution precooled at − 20 °C, regenerated cellulose beads mixed with γ-Fe2O3 nanoparticles (RC) were fabricated via a dropping technology. Subsequently, cellulose beads were oxidized by sodium periodate in dark room and nisin was anchored on the beads (NCs) through Schiff base reaction. The oxidization process and grafting reaction between the amino groups of nisin and the aldehyde groups of oxidized cellulose were confirmed via Fourier transform infrared spectra, field emission scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction. The beads containing γ-Fe2O3 nanoparticles exhibits the sensitive magnetic response and excellent thermal stability with decomposition temperature over 200 °C. A long-term antimicrobial activity against Alicyclobacillus acidoterrestris DSM 3922 were investigated. To the best of our knowledge, this is the first report of such nisin-anchored beads. The biodegradable nisin-anchored beads are novel antimicrobial materials with great potential in food industry.

Colorimetric detection of Escherichia coli using engineered bacteriophage and an affinity reporter system.

Reporter phage systems have emerged as a promising technology for the detection of bacteria in foods and water. However, the sensitivity of these assays is often limited by the concentration of the expressed reporter as well as matrix interferences associated with the sample. In this study, bacteriophage T7 was engineered to overexpress mutated alkaline phosphatase fused to a carbohydrate-binding module (ALP*-CBM) following infection of E. coli to enable colorimetric detection in a model system. Magnetic cellulose particles were employed to separate and concentrate the overexpressed ALP*-CBM in bacterial lysate. Infection of E. coli with the engineered phage resulted in a limit of quantitation of 1.2 × 105 CFU, equating to 1.2 × 103 CFU/mL in 3.5h when using a colorimetric assay and 100mL sample volume. When employing an enrichment step, < 101CFU/mL could be visually detected from a 100mL sample volume within 8h. These results suggest that affinity tag modified enzymes coupled with a material support can provide a simple and effective means to improve signal sensitivity of phage-based assays. Graphical abstract.

Immobilized lysozyme onto 1,2,3,4-butanetetracarboxylic (BTCA)-modified magnetic cellulose microsphere for improving bio-catalytic stability and activities

Novel carboxyl-functionalized core-shell magnetic cellulose microspheres (MCMS) were prepared by surface modification with 1,2,3,4-butanetetracarboxylic acid (BTCA) and then applied in the immobilization of lysozyme via covalent bonding. The successful preparation of particles has been verified by transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Fourier-transform infrared spectroscopy (FTIR) techniques. The optimal temperature and pH of the immobilized lysozyme were shown to be respectively 40 °C and 7. The immobilized lysozyme exhibited excellent performances within wide pH and temperature ranges as well as the high storage and thermal stabilities compared to free lysozyme. The apparent kinetic characterization of immobilized lysozyme revealed that its Km value was 1.37 times higher than that of free lysozyme and that its Vmax was slightly lower. The immobilized lysozyme demonstrated an acceptable reusability and showed 51.9±2.2% of activity after six cycles. This study demonstrated the application potential of BTCA-modified MCMS as an immobilized carrier for lysozyme.

Lipases immobilized on the modified polyporous magnetic cellulose support as an efficient and recyclable catalyst for biodiesel production from Yellow horn seed oil

In the present study, modified polyporous magnetic cellulose beads (PMCBs) were synthesized by several organic amines (EDA, DETA, TETA and AST) grafting PMCBs and then utilized as a new kind of support to immobilize Candida antarctica lipase B (CALB) for biodiesel production. The immobilized lipase catalysts based on PMCBs were characterized by Fourier transform infrared and scanning electron microscopy. The results showed that PMCBs-DETA was a more suitable immobilization support and the catalytic activity of immobilized lipases could reach 1.0 U/mg. Then the synthesized catalyst of CALB-PMCBs-DETA was used to produce biodiesel from Yellow horn seed oil via transesterification reaction. A high biodiesel yield (92.3%) was obtained under the optimal reaction conditions and the main compositions of the prepared biodiesel were tested by GC-MS. Moreover, the catalyst of CALB-PMCBs-DETA could be removed easily by a magnet and recycled at least 5 times. As a new kind of support, the modified PMCBs could be a promising alternative for the carriers of immobilizing enzymes used for the green and efficient production of biodiesel.

Simultaneous extraction and preconcentration of monomethylmercury and inorganic mercury using magnetic cellulose nanoparticles.

Magnetite (Fe3O4) nanoparticles were modified with nanocellulose and are showed to be a useful sorbent for magnetic solid-phase extraction of mercury species. Speciation analysis was performed by using gas chromatography coupled to atomic fluorescence detection (GC-pyro-AFS). The magnetic properties of the sorbent make this approach simple and rapid, and the use of a renewable and biodegradable nanomaterial (nanocellulose) makes it environmentally friendly. The factors that affect adsorption (pH value, amount of nanomaterial, time, volume of sample) and desorption (solvent, time) have been optimized. Both desorption and derivatization of mercury species were performed in a single step. This reduces considerably the sample preparation time. Under the optimized conditions, the limits of detection are 4.0pgmL-1 for monomethylmercury and 5.6pgmL-1 for inorganic mercury. The repeatability and reproducibility are satisfactory. The method enables inorganic mercury and monomethylmercury to be simultaneously extracted, with preconcentration factors up to 300. The potential interferences of organic matter and/or co-existing ions were also investigated using synthetic waters. The procedure was applied to the analysis of tap water and river water samples with different characteristics from a mercury polluted area (Almadén, Spain). The extraction recoveries ranged from 81 to 98% regardless of the type of water, which demonstrates the applicability of the method. This is the first time that this kind of sorbent is used for trace metal speciation. Graphical abstract Schematic representation of the new composite material (made of Fe3O4 magnetic nanoparticles and cellulose fibers, MCNPs) for the simultaneous extraction and preconcentration of mercury species taking advantage of the magnetic properties of this eco-friendly sorbent.

Colorimetric Analysis of Glucose Oxidase-Magnetic Cellulose Nanocrystals (CNCs) for Glucose Detection.

Glucose oxidase (EC 1.1.3.4) sensors that have been developed and widely used for glucose monitoring have generally relied on electrochemical principle. In this study, the potential use of colorimetric method for glucose detection utilizing glucose oxidase-magnetic cellulose nanocrystals (CNCs) is explored. Magnetic cellulose nanocrystals (magnetic CNCs) were fabricated using iron oxide nanoparticles (IONPs) and cellulose nanocrystals (CNCs) via electrostatic self-assembly technique. Glucose oxidase was successfully immobilized on magnetic CNCs using carbodiimide-coupling reaction. About 33% of GOx was successfully attached on magnetic CNCs, and the affinity of GOx-magnetic CNCs to glucose molecules was slightly higher than free enzymes. Furthermore, immobilization does not affect the specificity of GOx-magnetic CNCs towards glucose and can detect glucose from 0.25 mM to 2.5 mM. Apart from that, GOx-magnetic CNCs stored at 4 °C for 4 weeks retained 70% of its initial activity and can be recycled for at least ten consecutive cycles.

Brief evaluation of rapid test cassette for gammahydroxybutyric acid in urine

Counterfeiting of valuable documents, currency and branded products is a growing problem that has serious economic and security implications for governments and companies, as well as for ordinary people/customers. In order to prevent and detect falsification, continuous improvement of anticounterfeiting technology is required. This article presents the fabrication process and properties of the luminescent (upconverting)-magnetic cellulose fibers and their application in textiles. For the first time such functionalized fibers and corresponding luminescent-magnetic textiles are prepared. Cellulose fibers with bifunctional properties were obtained by core/shell type nanostructures based on lanthanide doped fluorides and magnetite nanoparticles. They show a bright red emission under the NIR excitation and magnetic response, along with very good mechanical properties. The fabric with upconverting-magnetic properties made of the as-prepared fibers is a perfect example of advanced, multimodal protection of materials such as textiles and documents against counterfeiting.

Directional preparation of superhydrophobic magnetic CNF/PVA/MWCNT carbon aerogel.

Carbon aerogels have attracted considerable attention in basic research and for their potential applications in many fields. Here, the fabrication of a magnetic cellulose nanofibre (CNF)/poly(vinyl alcohol) (PVA)/multiwalled carbon nanotubes (MWCNT) carbon aerogel (m-CPMCA) is reported using a simple freeze-drying followed by a carbonisation process, and direct immobilisation of Fe3O4 nanoparticle on the surface of aerogels. The obtained target aerogel has the characteristics of low density (0.098 g/cm3), high porosity (>90%) and 3D interpenetrating porous structures. Furthermore, m-CPMCA has a surprising compressive strength (about 0.35 MPa) which is obviously higher than many other cellulose-based carbon aerogels. After Carbonization, m-CPMCA exhibits superhydrophobicity, selective absorption for organic solvents and fire-resistance. The m-CPMCA also exhibited a magnetic response and can absorb oil on the water surface and can be actuated by a small magnet. More importantly, the m-CPMCA could be recycled many times by combustion, which showed economic significance. To sum up, the authors believe that m-CPMCA will become a very potential adsorbent for dealing with the increasingly serious problem of organic pollution.

Magnetic-controlled aerogels from carboxylated cellulose and MnFe2O4 as a novel adsorbent for removal of Cu(II)

The pore structure of the regenerated cellulose hydrogel was used as a microreactor for generating magnetic MnFe2O4 nanoparticles via in situ co-precipitation technology. Sodium periodate and sodium chlorite were used as oxidants, and the carboxyl modification of magnetic cellulose aerogels was achieved through a two-step oxidation reaction. The method used was convenient and environmental-friendly, and the raw materials were also green and non-toxic. The addition of magnetic nanoparticles promoted the adsorption and enabled the recycling of materials. The results showed that the adsorption equilibrium time was only 120 min and adsorption capacity could be increased by increasing the adsorption temperature. The maximum adsorption capacity of Cu(II) was 73.70 mg/g at 25 °C when the initial concentration of solution was150 mg/L. The adsorption behaviour towards Cu(II) followed the pseudo-secondary reaction kinetics and the Langmuir isotherm adsorption model. According to the results of XPS, carboxyl and hydroxyl groups were the main active adsorption sites for Cu(II). Moreover, all the composite aerogels exhibited good reusability and could be easily separated from the water after adsorption. The pore structure of the regenerated cellulose hydrogel was used as a microreactor for generating magnetic MnFe2O4 nanoparticles via in situ co-precipitation technology. Sodium periodate and sodium chlorite were used as oxidants, and the carboxyl modification of magnetic cellulose aerogels was achieved through a two-step oxidation reaction. According to the results of XPS, carboxyl and hydroxyl groups were the main adsorption sites for Cu(II). Moreover, all the composite aerogels exhibited good reusability and could be easily separated from the water after adsorption.

Cellulose-supported magnetic Fe3O4–MOF composites for enhanced dye removal application

Cellulose micro-fibrils (CMF), which are green, sustainable and are made from abundant renewable biomass, have attracted much attention in the research community for various applications. In this study, we presented a novel magnetic cellulose composite catalyst (HKUST-1/Fe3O4/CMF) for pollution remedy purpose. The main function of CMF is to improve the dispersion of metal organic framework (MOF) crystals (HKUST-1) and Fe3O4 nanoparticles (NPs) so that the catalytic performance of resultant HKUST-1/Fe3O4/CMF composite is enhanced. The as-prepared HKUST-1/Fe3O4/CMF catalyst was characterized by TEM, EDX, BET, XRD, FTIR, TGA and VSM analytical techniques. Results have showed that HKUST-1 and Fe3O4 NPs are anchored onto the surface of CMF. The adsorption efficiency of HKUST-1/Fe3O4/CMF composite has enhanced because of the porous MOF structures. Furthermore, the composite catalyst has a large surface area and exhibits good magnetic and catalytic properties in the Fenton system. When used as a catalyst in the degradation of dye model compound (methylene blue, MB), the composite catalyst shows a high catalytic activity. In addition, the composite catalyst reveals a good reusability, durability in the recycling and reuse testing. These results support to conclude that the as-prepared HKUST-1/Fe3O4/CMF composite is a green, sustainable, effective and potential catalyst system for pollutant remedy.

Magnetic cellulose nanoparticles as sorbents for stir bar-sorptive dispersive microextraction of polychlorinated biphenyls in juice samples

Magnetic cellulose nanoparticles (MCNPs) were used for the first time as sorbents for stir bar-sorptive dispersive microextraction (SBSDME). The main experimental parameters involved in the SBSDME process that affect extraction (i.e. amount of MCNPs, ionic strength, pH, extraction and back-extraction time) were investigated. The method was applied to the determination of nine polychlorinated biphenyls (PCBs) in fruit juice samples by gas chromatography–mass spectrometry (GC-MS). Under the optimized conditions, a good linearity was obtained in a concentration range of 10–1000 ng mL−1 with determination coefficients over 0.9945. Limits of detection and quantification for all target PCBs were in the range 2.1–54 ng L−1 and 7.0–180 ng L−1, respectively. Intra-day precision ranged from 1.7% to 8.8% and inter-day precision from 3.4% to 9.3% RSD. The enrichment factors of the analytes were from 74.6 to 98.2. The MCNPs can be reused up to 5 times. The method was applied to commercial orange and pineapple juices (n = 5), where concentrations were below the limits of detection. Recoveries from 70.4 to 108.0% were obtained by applying the method for the analysis of spiked fruit juice samples at 1 and 2 ng mL−1 concentration levels. The use of cellulose makes this approach environmentally friendly and the magnetism of the resulting sorbent in conjunction with SBSDME provides ease of handling and saving of time.

Influence of Nontoxic Magnetic Cellulose Nanofibers on Chitosan Based Edible Nanocoating: A Candidate for Improved Mechanical, Thermal, Optical, and Texture Properties.

The present work demonstrates the formulation of cellulose nanofiber (CNF) or magnetic cellulose nanofiber (mgCNF) dispersed chitosan-based edible nanocoating with superior mechanical, thermal, optical, and texture properties. The fabrication of mgCNF is successfully achieved through a single-step coprecipitation route, where iron particles get adsorbed onto CNF. The thermal stability of mgCNF is improved considerably, where ∼17% reduction in weight is observed, whereas CNF degrades completely under identical conditions. TGA analysis shows that there is an improvement in thermal stability for both CNF- and mgCNF-reinforced CS nanocoatings, where mgCNF provides more heat dimensional stability than CNF-dispersed CS nanocoatings. Further, the edible nanocoatings are stable even at the temperature of heat treatment such as food sterilization. The mechanical property of the mgCNF-dispersed chitosan (CS) shows a remarkable improvement in tensile strength (57.86 ± 14 MPa) and Young's modulus (2348.52 ± 276 MPa) in comparison to neat CS (6.27 ± 0.7 and 462.36 ± 64 MPa, respectively). To determine the developed materials to be safe for food, the quantification of iron is made by using ICP-MS technique. It is worth mentioning that mgCNF-coated CS helps in improving the texture of cut pineapples in comparison with uncoated pineapple slices under ambient conditions.

Reduction of 4-nitrophenol by a disused adsorbent: EDA-functionalized magnetic cellulose nanocomposite after the removal of Cu2+

In this paper, the fabrication of magnetically separable organic-inorganic hybrid nanoadsorbent via the functionalization of Fe3O4@SiO2@Cellulose with glycidyl methacrylate (GMA) and then ethylenediamine (EDA) was studied. The obtained nanocomposite system was characterized using FT-IR, XRD, SEM, EDX and VSM analyses. The EDA-functionalized magnetic cellulose exhibited a perfect capability towards removal of Cu2+ as well as Pb2+, Cd2+, Zn2+ and Ni2+ ions from the aqueous solutions. In addition, the influence of pH, contact time and initial concentration of Cu2+ were also investigated on capacity of the new designed cellulose absorbent. The examinations resulted that the adsorption process of Cu2+ is obeyed from the pseudo-second order kinetic model and the Langmuir isotherm. The maximum adsorption capacity of Cu2+ ions on the nanomagnetic cellulose was 81.67 mg/g. The magnetic cellulose after removal of Cu2+ ions was successfully applied as an efficient catalyst system for reduction of 4-nitrophenol to 4-aminophenol with excess amounts of NaBH4 in water.

Development of Cellulose Hydrogel Microspheres for Lipase Immobilization

Cellulose hydrogel microspheres were prepared by sol-gel transition using an ionic liquid-in-oil emulsion. Factors that influenced the formation of these microspheres, including the ratio of ionic liquid to oil, surfactant concentration, and stirring speed, were optimized for lipase immobilization. Using the optimized method, Candida rugosa lipase was efficiently immobilized on the microspheres by physical adsorption. As compared with the free lipase, the specific activity of the immobilized lipase was 1.4 times higher, its half-life at 45°C was 41 times longer, and it showed an enhanced stability over a wide pH range. The lipase immobilized on cellulose microspheres showed a much higher loading efficiency, immobilization yield, and specificity constant than lipase immobilized on microcrystalline cellulose or millimeter-sized hydrogel beads. To increase the reusability of cellulose microspheres as an enzyme support material, magnetic cellulose microspheres were also prepared by adding Fe3O4. The lipase immobilized on magnetic cellulose microspheres was simply recovered using a magnet and continuously reused with a minimal loss of activity.

Magnetic cellulose nanocrystal stabilized Pickering emulsions for enhanced bioactive release and human colon cancer therapy.

Stimuli-responsive drug release and controlled delivery play crucial roles in enhancing the therapeutic efficacy and lowering over-dosage induced side effects. In this paper, we report magnetically-triggered drug release and in-vitro anti-colon cancer efficacy of Fe3O4@cellulose nanocrystal (MCNC)-stabilized Pickering emulsions containing curcumin (CUR). The loading efficiency of CUR in the micron-sized (≈7 μm) MCNC-stabilized Pickering emulsions (MCNC-PE) template was found to be 99.35%. The drug release profiles showed that the exposure of MCNC-PE to external magnetic field (EMF) (0.7 T) stimulated the release of bioactive from MCNC-PE achieving 53.30 ± 5.08% of the initial loading over a 4-day period. The MTT assay demonstrated that the CUR-loaded MCNC-PE can effectively inhibits the human colon cancer cells growth down to 18% in the presence of EMF. The formulation also resulted in 2-fold reduction on the volume of the 3-D multicellular spheroids of HCT116 as compared to the control sample. The MCNC particle was found to be non-toxic to brine shrimp up to a concentration of 100 μg/mL. Our findings suggested that the palm-based MCNC-PE could be a promising yet effective colloidal drug delivery system for magnetic-triggered release of bioactive and therapeutics.

Recovery of Pt (IV) from aqueous solutions using magnetic functionalized cellulose with quaternary amine

ABSTRACTA new magnetic cellulose hybrids anchored with quaternary amine moieties were fabricated and used in recovering Pt(IV) ions from acidic solutions. Kinetic and thermodynamic parameters of adsorption process were reported through using batch experiments. An equilibrium uptake capacity of 178 mg g−1 was achieved within 55 min. The adsorption process was found to follow the pseudo-second-order kinetics and fitted well Langmuir and D-R adsorption isotherms revealing monolayer surface coverage and physisorption mechanism, respectively. At low pH values and high chloride concentration ranges, ion exchange was proposed as the predominant mechanism for the adsorption of Pt(IV) ions on the sorbent. The obtained sorbent showed good durability, easy separation, and regeneration from the adsorption medium.