甲壳胺纤维的螯合性能

把甲壳胺纤维与CuSO4和ZnSO4的水溶液处理后,通过控制处理的时间可以使纤维吸附不同含量的金属离子。研究了纤维上的金属离子的含量对纤维的物理机械性能的影响。结果表明,吸附金属离子后,纤维的干强和湿强都有明显的增加。纤维上的金属离子可以被EDTA的水溶液洗去,从而可以使纤维重复地应用于废金属离子的回收利用。把甲壳胺纤维进行乙酰化处理后,纤维可以在固体状态下转化成甲壳素纤维。实验结果表明,乙酰化后的纤维失去了它们对金属离子的螯合性能,从而证明了甲壳胺纤维的螯合性能主要来自于纤维上的自由胺基团。     

Absorption and release of zinc and copper ions by chitosan fibers

Chitosan fibers were treated with aqueous solutions of ZnCl₂ and CuSO₄·5H₂O to prepare zinc and copper containing fibers, respectively. Significant weight gains were obtained as the zinc and copper ions were absorbed onto the fibers through chelation with the primary amine groups. The fibers were then placed in contact with aqueous solutions containing NaCl and water soluble proteins, respectively, to assess the release of zinc and copper ions. Results showed that the release of zinc and copper ions were affected by the treatment temperature, time, and the composition of the contacting media. More metal ions were released when the fibers were in contact with aqueous protein solutions than in NaCl solution, indicating the binding abilities of the protein molecules for zinc and copper ions. The zinc and copper containing fibers were tested for their antimicrobial effects against several species of bacteria commonly found in wound and skin. Results showed that these metal containing chitosan fibers had much stronger antimicrobial properties than the original chitosan fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation of amidoximated polyester fiber and competitive adsorption of some heavy metal ions from aqueous solution onto this fiber

In this study, a fibrous adsorbent containing amidoxime groups was prepared by graft copolymerization of acrylonitrile (AN) onto poly(ethylene terephthalate) (PET) fibers using benzoyl peroxide (Bz₂O₂) as initiator in aqueous solution, and subsequent chemical modification of cyano groups by reaction with hydroxylamine hydrochloride in methanol. The grafted and modified fibers were characterized by FTIR, TGA, SEM, and XRD analysis. The crystallinity increased, but thermal stability decreased with grafting and amidoximation. The removal of Cu(II), Ni(II), Co(II), Pb(II), and Cd(II) ions from aqueous solution onto chelating fibers were studied using batch adsorption method. These properties were investigated under competitive conditions. The effects of the pH, contact time, and initial ion concentration on the removal percentage of ions were studied. The results show that the adsorption rate of metal ions followed the given order Co(II) > Pb(II) > Cd(II) > Ni(II) > Cu(II). The percentage removal of ions increased with initial ion concentration, shaking time, and pH of the medium. Total metal ion removal capacity was 49.75 mg/g fiber on amidoximated fiber. It was observed that amidoximated fibers can be regenerated by acid without losing their activity, and it is more selective for Pb(II) ions in the mixed solution of Pb‐Cu‐Ni–Co‐Cd at pH 4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Cu(II) Adsorption of Activated Carbon Fibers Produced by Radiation-Induced Graft Polymerization

In this work, the adsorption behaviors of activated carbon fibers (ACFs) containing chelating functional groups were studied in heavy metal ion removal. The ACFs were modified by electron beam and glycidyl methacrylate (GMA, CH₂—CCH₃COOCH₂CHOCH₂) graft polymerization in order to induce chelating functional groups, such as iminodiacetate (IDA, NH(CH₂COOH)₂) groups on the ACF surfaces. Fourier transform-infrared spectrometry (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface properties of the ACFs. The specific surface area and the pore structure were evaluated from nitrogen adsorption data at 77 K. The adsorbed amount of heavy metal ions was measured by using inductively coupled plasma-atomic emission spectrometer (ICP-AES). Results of FT-IR and XPS showed that the relative intensity of oxygen peaks increased with increasing the dose of electron beam. The results indicated that the radicals were increased as the dose of electron beam irradiation increased, and increased radicals led to the increase of the IDA groups. Also, the adsorption of heavy metal ions was increased by increasing the dose of electron beam irradiation. It was explained that the IDA groups of the treated ACF surfaces were introduced by radiation-induced graft polymerization and the increased IDA groups led to an increase of the adsorption of heavy metal ions.     

The absorption and release of silver and zinc ions by chitosan fibers

When chitosan fibers were treated with AgNO₃ and ZnCl₂ solutions, the silver and zinc ions were chelated by chitosan through the amine groups in the fibers. These novel metal ions can be released into the solution when the silver‐ and zinc‐containing fibers are placed in contact with normal saline. Results showed that the silver‐containing chitosan fibers have good antimicrobial properties, while the zinc‐containing fibers can be used to deliver zinc ions in wound care applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 766–771, 2006     

羧甲基甲壳胺纤维对铜离子的吸附性能

为了提高甲壳胺纤维对重金属离子的吸附性能,用氯乙酸对纤维进行改性处理,在纤维的结构中引入羧甲基团后使纤维同时具有能结合重金属离子的胺基和羧酸基团。研究了改性后纤维在不同的改性程度、添加量、时间、温度、pH值等条件下对铜离子的吸附性能。结果表明:羧甲基化改性后的甲壳胺纤维对铜离子有很好的吸附性能。在同样的条件下,未改性的纤维对铜离子的吸附值为41.3mg/g,而改性后的纤维为79.4mg/g。经过羧甲基化改性的甲壳胺纤维对铜离子的饱和吸附容量可以达到148.1mg/g。     

Development of novel adsorbent materials for recovery and enrichment of uranium from aqueous media

A new polymeric adsorbent bearing both hydrophilic groups providing swelling in water and amidoxime groups for chelating with uranyl ions (UO₂²⁺), has been developed and its adsorptive ability for recovering uranium from aqueous media has been investigated. The polymers obtained by irradiating the solution of polyethylene glycol (PEG) in acrylonitrile (AN) are defined as interpenetrating polymer networks (IPNs) and the adsorbent has been obtained by applying the amidoximation reaction to the IPNs with a conversion ratio of ∼ 60%. Kinetics of the conversion reaction of the cyano (CN) group to the amidoxime (HONCNH₂) group has been studied by reacting with hydroxylamine (NH₂OH) solution at a molar ratio of NH₂OH/CN = 1.25 in aqueous media at three different temperatures, 30, 40, and 50°C, for 3–4 days. The degree of amidoximation ratio was determined by UO₂²⁺ ion adsorption and FTIR spectrometry and the UO₂²⁺ ion adsorption values were found by both UV and gamma spectrometry and also by gravimetry. It was found that the polymeric adsorbent has a very high adsorption ability for uranium and quite a good stability in aqueous media. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2475–2480, 1997     

Adsorption of Cd(II), Pb(II), and Ag(I) in aqueous solution on hollow chitosan microspheres

Cross‐linked chitosans synthesized by the inverse emulsion cross‐link method were used to investigate adsorption of three metal ions [Cd(II), Pb(II), and Ag(I)] in an aqueous solution. The chitosan microsphere, was characterized by FTIR and SEM, and adsorption of Cd(II), Pb(II), and Ag(I) ions onto a cross‐linked chitosan was examined through analysis of pH, agitation time, temperature, and initial concentration of the metal. The order of adsorption capacity for the three metal ions was Cd²⁺ > Pb²⁺ > Ag⁺. This method showed that adsorption of the three metal ions in an aqueous solution followed the monolayer coverage of the adsorbents through physical adsorption phenomena and coordination because the amino (? NH₂) and/or hydroxy (? OH) groups on chitosan chains serve as coordination sites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Formation of thermosensitive copolymer beads having phosphinic acid groups and adsorption ability for metal ions

Hydrophilic thermosensitive copolymer beads having phosphinic acid groups were prepared by suspension copolymerization of acryloyloxypropyl n‐octylphosphinic acid (APPO), N‐isopropyl acrylamide (NIPAAm), and tetraethyleneglycol dimethacrylate (4G). The thermosensitivity and the adsorption ability of the copolymer beads for metal ions beads were studied. The APPO‐NIPAAm‐4G copolymer beads were obtained in a good yield by suspension copolymerization of monomers (APPO, NIPAAm, and 4G) dissolved in chloroform, in a saturated Na₂SO₄ aqueous solution in the presence of surfactant and MgCO₃. The APPO‐NIPAAm‐4G copolymer beads had higher adsorption ability for lanthanide metal ions (Eu³⁺, Sm³⁺, Nd³⁺, or La³⁺) than for main transition metal ions (Cu²⁺, Ni²⁺, or Co²⁺). Furthermore, it was also found that the APPO‐NIPAAm‐4G copolymer beads had selective adsorption ability between lanthanide metal ions, and the order of adsorption ability for lanthanide metal ions was as follows: Eu³⁺ > Sm³⁺ > Nd³⁺ > La³⁺. The selective adsorption for these metal ions from their mixed solutions was performed by both a batch method and a column method. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 449–460, 2006     

Synthesis of new chelating ion exchange resin with hydroxamic and amidoxime groups and study of its metal binding property

The synthesis of a new chelating ion exchanger with hydroxamic and amidoxime groups was performed by an aminolysis reaction of an ethylacrylate/acrylonitrile/divinylbenzene copolymer with hydroxylamine in the presence of sodium ethoxylate. We studied the retention property of the new resin for Pb(II), Cd(II), Cu(II), Ni(II), Zn(II), Mn(II), and Fe(III) metal cations from aqueous solutions. The retention capacity depends on the contact time, the pH of the solution, and the types of counterions of the metal cations. Competitive adsorptions of Pb(NO₃)₂ + Fe₂(SO₄)₃, Pb(NO₃)₂ + MnSO₄, Pb(NO₃)₂ + Cd(NO₃)₂, and Pb(NO₃)₂ + CuCl₂ on the new chelating ion exchanger were performed. The results showed that the resin preferentially retained the Pb(II) ions from the binary aqueous mixtures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2956–2962, 2003     

EXTRACTION OF HEAVY METAL IONS WITH 3-[(DIOCTYLAMINO)METHYL]ALIZARIN

3-[(Dioctylamino)methyl]alizarin (C₈AL), which is endowed with high solubility in nonpolar organic solvents through introduction of dioctylaminomethyl group into the alizarin nucleus was studied for extracting heavy metal ions such as Cu(II), Zn(II), Cd(II), Co(II), Mn(II), and Ni(II), from aqueous solution.Cu(II) was most readily extracted into chlorobenzene at low pH and thus was separated from other metal ions. The metal ions stabilized in alkaline solution in the presence of water-soluble chelating agents were found to be extracted by this, alizarin-type extraction agent into chlorobenzene with the assistance by lipophilic quaternary ammonium salt, Capriquat? (methyltrioctylammonium chloride, Q^?C1^?).The proton dissociation process of CRAL was studied, and the mechanism of these metal extractions was discussed.The separation of Cu(II) and Ni(II) from the mixture with other divalent metal ions was also studied.     

Poly(N-vinylcaprolactam) gel/organic dye complexes as sensors for metal ions in aqueous salt solutions

The complex formation of organogels based on poly(N-vinylcaprolactam) (PVCa) and organic dyes [5-(4-dimethylaminobenzylidene) rhodanine, α-nitroso-β-naftol, and dithizone] and the properties of the complexes in salt aqueous solutions were studied. PVCa gels absorbed these dyes in organic media (ethanol and chloroform). Our main focus was the behavior of the gel/dye complex immersed in a salt aqueous solution if the dye was the chelating ligand for metal ions. The behavior of the PVCa/dithizone (Dz)/chloroform system was studied in AgNO₃ aqueous solutions. The absorption spectra of gel/dye and gel/dye/metal ion systems were investigated. The results obtained indicate that Ag⁺ ions penetrate the gel phase and that the Dz/silver complexes are indeed formed inside the gel. The dependence of the optical density of the gel/dye/metal ion systems on the AgNO₃ concentration was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3238–3243, 2001     

Preparation of iminodiacetic acid-type composite chelating material IDAA-PGMA/SiO2 and preliminary studies on adsorption behavior of heavy metal ions and rare earth ions

A kind of iminodiacetic acid (IDAA)-type composite chelating materials was prepared by first graft polymerization and subsequent polymer reaction. Monomer glycidyl methacrylate (GMA) was grafted on micron-sized silica gel particles in the manner of “graft through” in a solution polymerization system, resulting in the grafted particles poly(glycidyl methacrylate) (PGMA)/silicon dioxide (SiO₂). Subsequently, the ring-opening reaction of the epoxy groups of the grafted PGMA was carried out with IDAA as reaction reagent, resulting in the bonding of IDAA groups onto PGMA/SiO₂ and obtaining the composite chelating material IDAA-PGMA/SiO₂ particles. The effects of the main factors on the graft polymerization of GMA and the bonding reaction of IDAA were examined emphatically, and the adsorption behavior of IDAA-PGMA/SiO₂ particles toward several kinds of heavy metal ions and rare earth ions was preliminarily explored. The experiments results show that: (a) to obtain the grafted particles PGMA/SiO₂ with high grafting degree, in the graft polymerization step, the reaction temperature and the used amount of initiator should be controlled. The suitable temperature is 70°C and the appropriate used amount of initiator is 1.4 % of the monomer mass. Under the optimal conditions, the grafted degree of PGMA can reach 17.50 g/100 g. (b) It is feasible to introducing of IDAA groups onto PGMA/SiO₂ particles via ring-opening reaction of epoxy groups of the grafted PGMA under alkaline conditions, and the bonding rate of IDAA group can get up to 70% based on epoxy groups of the grafted PGMA. (c)The composite chelating material IDAA-PGMA/SiO₂ possesses very strong chelating adsorption ability for heavy metal ions, and especially toward Pb²⁺ ion, the adsorption capacity can reach 24 g/100 g. (d) The adsorption ability of IDAA-PGMA/SiO₂ for rare earth ions is weaker than that for heavy metal ions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of Chelating Resins Containing a Pair of Neighboring Carboxylic Acid Groups and the Adsorption Characteristics for Heavy Metal Ions

Abstract

For the functional enhancement of chelating resins containing carboxylic acids, copolymer beads were prepared by suspension polymerization of styrene (St), methyl methacrylate (MMA), and divinylbenzene (DVB) in the presence of toluene as diluent. The phenyl rings of the beads were directly chloromethylated, and the carboxylic ester groups of the beads were converted into hydroxymethyl groups by reduction followed by chlorination to give chloromethyl groups, respectively. The chelating resins containing a pair of neighboring carboxylic acid groups (NCAGs) were obtained by the alkylation of chloromethyl groups in copolymer beads with diethyl malonate in the presence of sodium hydride followed by hydrolysis using aqueous alkali solution. Accordingly, the structural effects of the resins on the adsorption of heavy metal ions were investigated. Poly(St‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb²⁺, Cd²⁺, and Cu²⁺, whereas poly(MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Cu²⁺, Cd²⁺, and Co²⁺. On the other hand, poly(St‐co‐MMA‐co‐DVB)‐based chelating resin containing NCAGs showed adsorption abilities toward heavy metal ions like Pb²⁺, Cd²⁺, Hg²⁺, Co²⁺, and Cu²⁺: a synergistic effect on the adsorption of heavy metal ions like Pb²⁺, Cd²⁺, Hg²⁺, and Co²⁺ was observed. The adsorption ability of poly(St‐co‐MMA‐co‐DVB)‐based chelating resin among three kinds of chelating resins was relatively good.     

Cellulose and chitosan based magnetic nanocomposite microspheres and its application

In this work, a simple and green method is used to fabricate magnet nanocomposite microspheres (cellulose/chitosan/Fe₃O₄) based on cellulose/chitosan microsphere via the interaction between metal ions with chitosan. The results of Fourier transform infrared spectra and X-ray diffraction indicated that the Fe₃O₄ nanoparticles were well-fixed in the network of cellulose/chitosan microsphere as a result of the chelation role between chitosan and metal ions. Moreover, the morphology of Fe₃O₄ nanoparticle can be adjusted by changing the chitosan concentration of cellulose/chitosan microsphere. Most important, the catalytic performance of the nanocomposite magnet microsphere was studied, and the magnet nanocomposite microspheres with face-centered cubic structure and less size of Fe₃O₄ nanoparticles have shown excellent catalytic performance. Based on their excellent catalytic properties, these magnet cellulose/chitosan/Fe₃O₄ microspheres have prospect applications in the field of biotechnology and environmental, and so on.     

IR spectroscopic investigation of interaction between sodium aluminosilicate electrode glasses and aqueous solutions

The effect of introduction of aluminum oxide into the composition of sodium silicate glasses has been studied by IR absorption and reflection spectroscopy. The change in the spectroscopic characteristics of glasses after their treatment with HNO₃ and AgNO₃ aqueous solutions is analyzed. The concentration profiles of Na₊ and Ag₊ ions in the surface layers of these glasses are determined by the HF-sectioning technique. It is found that silver ions predominantly interact with the [AlO_4/2]^- groups in the glass. The leaching of sodium ions, formation of amorphous silica in the surface layers of the treated glass samples, and exchange of sodium ions by hydrogen ions are revealed from changes in the spectra.     

Synthesis of a polyacrylamidoxime chelating fiber and its efficiency in the retention of palladium ions

A chelating fibrous polymer with metal complexing ability was prepared by partial conversion of the nitrile groups of melana (an acrylonitrile‐based synthetic fiber) into amidoxime groups ? C(NH₂) = NOH using a solution of 3% hydroxylamine in methanol by refluxing at 80°C. The molar ratio of NH₂OH/CN and the reaction time were adjusted to values of 0.9 and 2 h, respectively. The amidoximated polyacrylonitrile fiber with a 2.89 meq/g ion‐exchange capacity functions as an efficient chelating adsorbent for palladium ions. The pH dependence, the contact time, and the temperature of palladium ion retention from a model solution on amidoximated acrylic fiber were studied. The fibrous chelating adsorbent exhibited high affinity for palladium ions in acidic solution (pH = 2–6) at high temperature (50–60°C). The values of parameters q_m and K_L (from the Langmuir equation) determined at different temperatures of adsorption and the thermodynamic quantities ΔG, ΔH, and ΔS were calculated. The adsorbed palladium ions can be quantitatively desorbed by elution with a 0.3% hydrochloric solution of thiourea. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3730–3735, 2004     

Use of chitosan derivatives as solid phase extractors for metal ions

This paper shows a comparative study between the two radiation grafted chitosan derivatives viz. cross-linked chitosan (CRC) and cross-linked chitosan after hydrolysis (CRCH). These chitosan derivatives were used as solid phase extractors for several radionuclides. The uptake of ¹³⁷Cs, ^85,89Sr, ¹⁵²Eu, ²⁴¹Am, ²³⁴Th and ²³³U by CRCH and CRC was studied using batch and column methods. The K_d, exchange capacity, breakthrough capacity for different metal ions with the functionalized polymers were determined. The uptake followed the following trend: UO₂²⁺>Th⁴⁺>Cs⁺>Eu³⁺>Am³⁺>Sr²⁺ for both sorbents. It was seen that CRCH has a greater uptake of metal ions compated to CRC but CRC was more selective of the two.     

IR spectroscopic investigation of interaction between sodium aluminosilicate electrode glasses and aqueous solutions

The effect of introduction of aluminum oxide into the composition of sodium silicate glasses has been studied by IR absorption and reflection spectroscopy. The change in the spectroscopic characteristics of glasses after their treatment with HNO₃ and AgNO₃ aqueous solutions is analyzed. The concentration profiles of Na₊ and Ag₊ ions in the surface layers of these glasses are determined by the HF-sectioning technique. It is found that silver ions predominantly interact with the [AlO_4/2]^- groups in the glass. The leaching of sodium ions, formation of amorphous silica in the surface layers of the treated glass samples, and exchange of sodium ions by hydrogen ions are revealed from changes in the spectra.     

Effect of chitosan addition to BTCA/CA processed cotton fabrics for adsorbing metallic ions from waste water

One of the most important properties of chitosan, a derivative of chitin, is that it is able to chelate with certain heavy metal ions, and this property can be applied to process waste water containing heavy metal ions. In this research, using BTCA/CA as a crosslinking reagent with chitosan added, cotton fabrics were cured and allowed to undergo an adsorption reaction in CuSO₄ and ZnSO₄ solutions. The effect of different curing temperatures and time, as well as different adsorptive temperatures and time, were studied. The cotton processed fabrics were analyzed by Fourier transform infrared analysis (FTIR), scanning electronic microscope (SEM), and thermal gravity analysis (TGA) to study the crosslinking reaction with the cotton‐processed fabrics. The results indicate: (1) the BTCA/CA‐processed cotton fabrics with an addition of chitosan have a better adsorptive capacity than the processed fabrics without chitosan; (2) the crosslinked fabrics are better in adsorbing copper ions as chitosan concentration, curing temperature and time, and adsorptive temperature and time increase; (3) the adsorption rate of copper and zinc ions are linearly proportional to the changes of time, so that the slope shows that the adsorption rate of crosslinked fabrics for copper ions is faster than for zinc ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3264–3269, 2006