Preparation of crosslinked polystyrene-supported ethylenediamine via a S-containing spacer and adsorption properties towards metal ions

Two novel chelating resins were prepared by anchoring ethylenediamine to crosslinked polystyrene via a spacer containing sulfide. Their structures were characterized by Fourier transform-infrared spectra (FTIR) and scanning electron microscopy (SEM). Porous structure parameters of the resins were measured by ASAP 2020 using BET and BJH methods. Their adsorption capacities for several heavy metal ions especially Hg²⁺ were investigated. The results showed that for the two resins, the more N contents did not mean the better adsorption capacity and the saturated adsorption capacity of poly(2-ethylenediamidomercaptomethylstyrene) (PSM-EDA) for Hg²⁺ could reach to 3.0 mmol/g at room temperature. Isothermal adsorptions of the resins for Hg²⁺ could be described by Langmuir formula. The adsorption mechanism of the resins for Hg²⁺, Cu²⁺ and Ag⁺ was confirmed by X-ray photoelectron spectroscopy (XPS) and FTIR.     

Synthesis of a Dithiocarbamate Chelate Resin and Its Oxidized form and Their Adsorption Properties for Heavy Metal Ions

A series of macroporous dithiocarbamate chelate resins, III and V, and an oxidized resin, VI, with high adsorption capacity were prepared. The influence of various reaction conditions of amination, dithiocarboxylation, and oxidation were examined. The structure and the conversion of functional groups of resins were confirmed by IR spectra and elemental analysis. The adsorption capacities of Resin II for Hg²⁺, Cu²⁺, Zn²⁺, and Cd²⁺ are 4.40, 2.44, 1.77, and 1.36 mmol/g, respectively. The adsorption capacities of Resins V and VI for Cu²⁺. Zn²⁺, Ni²⁺, Co³⁺, Ag⁺, Hg²⁺, Cd²⁺, Pb²⁺, and Au³⁺ are 4.07–0.51 and 3.81–0.59 meq ion/g, respectively. The adsorption rate and the influence of pH on the adsorption percentage of the resins for metal ions were examined. Noble metal, transitional metal, and heavy metal ions can be quantitatively adsorbed by the resins. The adsorbed Cu²⁺, Pb²⁺, Cd²⁺, Co³⁺, and Ni²⁺ can be quantitatively eluted with 5N HNO₃, and the presence of large amounts of Ca²⁺, Mg²⁺, Fe³⁺, and Al³⁺ did not interfere.     

聚乙烯苄多乙烯多胺二硫代羧酸大孔型螯合树脂合成与性质的研究

合成了具有高吸附容量的聚乙烯苄多乙烯多胺二硫代羧酸大孔型螫合树脂(DTC树脂)。探讨了胺化和二硫代羧化中各种反应条件的影响。制得的DTC树脂对Hg~(2+)、Cu~(2+)、Zn~(2+)、Cd~(2+)的吸附容量分别达4.40、2.44、1.77、1.36毫摩尔离子/克,在水中对微量的重金属离子在较宽pH范围内有良好的捕集效果。红外光谱、元素分析证实了合成过程中树脂功能基的转化。     

PREPARATION AND PROPERTIES OF MACRO-POROUS CHELATE RESINS OF CROSSLINKED POLYSTYRENE BEARING DITHIOCARBAMATE GROUPS

The title resins (DTC resins) with high adsorption capacity were prepared. The influences of various reaction conditions of amination and dithiocarboxylation were examined. The adsorption capacities of the produced DTC resin for Hg~(2 ), Cu~(2 ), Zn~(2 ) and Cd~(2 ) are 4.40, 2.44, 1.77 and 1.36 mmol/g, respectively. It is highly effective in collecting traces of heavy metal ions in water over a wide pH range. The conversion of the functional groups were confirmed by the IR-spectra and elementary. analysis.     

A chelating resin with bis[2-(2-benzothiazolylthioethyl)sulfoxide]: Synthesis, characterization and properties for the removal of trace heavy metal ion in water samples

A new chelating resin containing bis[2-(2-benzothiazolylthioethyl)sulfoxide] was synthesized using chloromethylated polystyrene as material and characterized by elemental analysis and infrared spectra. The adsorption capacities of the newly formed resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, Pb²⁺, Mn²⁺, Ni²⁺, Cd²⁺ and Fe³⁺ were investigated over the pH range 1.0-6.0. The resin exhibited no affinity for alkali or alkaline earth metal ions. The maximum adsorption capacities of the resin for Hg²⁺, Ag⁺, Cu²⁺, Zn²⁺, Pb²⁺, Mn²⁺, Ni²⁺, Cd²⁺ and Fe³⁺ were 1.49, 0.96, 0.58, 0.11, 0.37, 0, 0.24, 0.36 and 0.25 mmol g⁻¹, respectively. In column operation it had been observed that Hg²⁺ and Ag⁺ in trace quantity could be separated from different binary mixtures and Hg²⁺ could be effectively removed from industrial wastewater and the natural water spiked with Hg²⁺ at usual pH.     

Abtrennung von Schwermetallionen mit Polystyrolaustauschern

Zusammenfassung Die Abtrennung von Cu²⁺, Fe³⁺, Hg²⁺, Au³⁺, Ag⁺, Pd²⁺ und UO ₂ ²⁺ aus Salzlösungen oder organischen Lösungsmitteln in Trennsäulen mit Hilfe von Polystyrolaustauschern, die Tiron, DMABR, TAM oder Glyoxal-bis (2-hydroxyanil) als Ankergruppen enthalten, wird beschrieben.

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Separation of heavy metal ions with polystyrene exchangers

Summary The separation of Cu²⁺, Fe³⁺, Hg²⁺, Au³⁺, Ag⁺, Pd²⁺ and UO ₂ ²⁺ from salt solutions or organic solvents in separation columns by means of polystyrene exchangers containing Tiron, DMABR, TAM or glyoxal-bis(2-hydroxyanil) as anchor groups is described.

     

Mo3S132− Intercalated Layered Double Hydroxide: Highly Selective Removal of Heavy Metals and Simultaneous Reduction of Ag+ Ions to Metallic Ag0 Ribbons

We demonstrate a new material by intercalating Mo₃S₁₃^2? into Mg/Al layered double hydroxide (abbr. Mo₃S₁₃-LDH), exhibiting excellent capture capability for toxic Hg²⁺ and noble metal silver (Ag). The as-prepared Mo₃S₁₃-LDH displays ultra-high selectivity of Ag⁺, Hg²⁺ and Cu²⁺ in the presence of various competitive ions, with the order of Ag⁺>Hg²⁺>Cu²⁺>Pb²⁺≥Co²⁺, Ni²⁺, Zn²⁺, Cd²⁺. For Ag⁺ and Hg²⁺, extremely fast adsorption rates (≈90 % within 10 min, >99 % in 1 h) are observed. Much high selectivity is present for Ag⁺ and Cu²⁺, especially for trace amounts of Ag⁺ (≈1 ppm), achieving a large separation factor (SF_Ag/Cu) of ≈8000 at the large Cu/Ag ratio of 520. The overwhelming adsorption capacities for Ag⁺ (q_m^Ag=1073 mg g^?1) and Hg²⁺ (q_m^Hg=594 mg g^?1) place the Mo₃S₁₃-LDH at the top of performing sorbent materials. Most importantly, Mo₃S₁₃-LDH captures Ag⁺ via two paths: a) formation of Ag₂S due to Ag-S complexation and precipitation, and b) reduction of Ag⁺ to metallic silver (Ag⁰). The Mo₃S₁₃-LDH is a promising material to extract low-grade silver from copper-rich minerals and trap highly toxic Hg²⁺ from polluted water.     

Preparation and metal binding behavior of poly(4-vinylbenzyl 2-hydroxyethyl) sulfoxide and sulfone

In order to explore the reuse properties of oxidized chelating resin containing sulfur after adsorption, two kinds of novel chelating resins, poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfoxide (PVBSO) and poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfone (PVBSO₂), were synthesized using poly[4-vinylbenzyl-(2-hydroxyethyl)] sulfide (PVBS) as material. Their structures were confirmed by FTIR and XPS. The adsorption properties and mechanism for metal ions such as Au³⁺, Pt⁴⁺, Pd²⁺, Hg²⁺, Cu²⁺, Ni²⁺, Fe³⁺, Pb²⁺, Cd²⁺, and Zn²⁺ were investigated. Experimental results showed that PVBSO had good adsorption and selective properties for Au³⁺, Pd²⁺ and Cu²⁺ when the coexisting ion was Pt⁴⁺, Ni²⁺, Pb²⁺ or Cd²⁺. In the aqueous system containing Cu²⁺ and Pb²⁺ or Cu²⁺ and Cd²⁺, PVBSO₂ only adsorbed Cu²⁺. The selective coefficients of PVBSO and PVBSO₂ were α_Au/Pt = 4.8, α_Au/Pd = 11.8, α_Pd/Pt = 10.9, α_Cu/Ni = 2.5, α_Cu/Cd = 41.2, α_Cu/Pb = ∞, α_Cu/Ni = 3.0, α_Cu/Cd = ∞, α_Cu/Pb = ∞, respectively.     

Detection of Metal Ions (Cu2+, Hg2+) and Cocaine by Using Ligation DNAzyme Machinery

The Cu²⁺‐dependent ligation DNAzyme is implemented as a biocatalyst for the colorimetric or chemiluminescence detection of Cu²⁺ ions, Hg²⁺ ions, or cocaine. These sensing platforms are based on the structural tailoring of the sequence of the Cu²⁺‐dependent ligation DNAzyme for specific analytes. The tethering of a subunit of the hemin/G‐quadruplex DNAzyme to the ligation DNAzyme sequence, and the incorporation of an imidazole‐functionalized nucleic‐acid sequence, which acts as a co‐substrate for the ligation DNAzyme that is tethered to the complementary hemin/G‐quadruplex subunit. In the presence of different analytes, Cu²⁺ ions, Hg²⁺ ions, or cocaine, the pretailored Cu²⁺‐dependent ligation DNAzyme sequence stimulates the respective ligation process by combining the imidazole‐functionalized co‐substrate with the ligation DNAzyme sequence. These reactions lead to the self‐assembly of stable hemin/G‐quadruplex DNAzyme nanostructures that enable the colorimetric analysis of the substrate through the DNAzyme‐catalyzed oxidation of 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid), ABTS^2?, by H₂O₂ into the colored product ABTS^.?, or the chemiluminescence detection of the substrate through the DNAzyme‐catalyzed oxidation of luminol by H₂O₂. The detection limits for the sensing of Cu²⁺ ions, Hg²⁺ ions, and cocaine correspond to 1 nM , 10 nM and 2.5 μM , respectively. These different sensing platforms also reveal impressive selectivities.     

Determination of maximum loading capacity of polyamidoamine (PAMAM) dendrimers and evaluation of Cu55 dendrimer‐encapsulated nanoparticles for catalytic activity

Spectrophotometric titrations provide information about the interior of the polyamidoamine (PAMAM) dendrimers, and therefore how nanoparticles are encapsulated. In this work, binding studies were performed to determine maximum loading capacities (N) of hydroxyl terminated G4, G5, and G6 PAMAM dendrimers with Cu²⁺ ions. The values of N found via spectrophotometric titrations were 16.22, 31.86, and 57.36 for G4‐OH, G5‐OH, and G6‐OH, respectively. The determination of loading capacity was also done using Viva spin filtration, and the results were found to be in agreement with those found via spectrophotometric titrations. From the binding isotherm, the values of equilibrium constant (K′) were determined and found to be 0.0488 (G4‐OH), 0.0291 (G5‐OH), and 0.0158 (G6‐OH). Owing to instability of G4‐OH (Cu₁₆), G5‐OH (Cu₃₂), and G6‐OH (Cu₅₇) dendrimer‐encapsulated nanoparticles (DENs) synthesized, G6‐OH (Cu₅₅) DENs of average size 2.6 ± 0.3 nm were prepared and were found to be relatively stable. Thus G6‐OH (Cu₅₅) catalyst was evaluated for the reduction of 4‐nitrophenol and was found to be catalytically active toward reduction of 4‐nitrophenol. Reaction kinetics of 4NP reduction was thoroughly studied in light of the Langmuir‐Hinshelwood kinetic model, and surface rate k, and the adsorption rates K_4NP, and K_BH4 were determined. The reaction was performed at different temperatures, which further expanded the study into determination of thermodynamic (ΔH^‡, ΔS^‡, ΔG^‡, and E_A) parameters.     

Preconcentration of metal ions using an immobilized dialkyldithiocarbamate in a flow system

Flow injection analysis with on-line preconcentration using a minicolumn loaded with dialkyldithiocarbamate immobilized on controlled pore glass is described for the determination of Rh(III), Co²⁺, Cu²⁺, Hg²⁺, and Hg₂²⁺. The detection limits range from 0.05 ng ml⁻¹ for Cu²⁺ to 50 ng ml⁻¹ for Hg²⁺ for 5- or 10-ml samples, improvement of 2–3 orders of magnitude compared with direct injection. The operating conditions are optimized and the effects of interferents are studied. The capacity of the collector varied from 0.9 mmol g⁻¹ for Rh(III) to ca 4 mmol g⁻¹ (Co²⁺, Cu²⁺, Hg²⁺).     

Metal adsorption properties of multi-functional PAMAM dendrimer based gels

Metal adsorption studies are getting important and there are many functional adsorbents developed recently. Here, we report the synthesis of multifunctional PAMAM G2 (polyamidoamine) possessing methacryl, amine, hydroxyl and phosphonate groups used in free radical curing gel formulations. UV curable gel is conducted in the presence of acrylamide, bisacrylamide, and polyethylene glycol diacrylate. Adsorption study of the resulting novel sorbents (gels) are carried out with a series of metals. Through a comprehensive study, structure–property relationship of the series gels is conducted by using different amount of amine, hydroxyl, and/or phosphonate ester groups on the PAMAM G2. Selected metals are Cr³⁺, Fe³⁺, Ni²⁺, Cu²⁺, Ag⁺, and Cd²⁺ within a series of hard, intermediate, and soft ionic species. Adsorption study is carried out in pure water environment at neutral pH. Metal ions removal percentages and adsorption capacities of gel adsorbents are calculated by using atomic absorption spectroscopy. There is relationship between the overall functional groups presence in gel formulation and swelling densities for removing the metal ions. Introducing dendrimer into the gel formulation enhanced the metal ions adsorption against to Bare GEL formulation which do not possess dendrimer units. Consequently, the maximum removal efficiency has been obtained for Cr³⁺ and Fe³⁺.     

以聚苯乙烯树脂为载体的缩硫醛大环螯合树脂的合成和性能研究

以大孔聚苯乙烯树脂为载体,合成了具缩硫醛大环的螯合树脂。它对Hg~(2+)的络合容量可达30—60mgHg~(2+)/g树脂,比对Ca~(2+)、Zn~(2+)、Cd~(2+)、Pb~(2+)等金属离子的络合容量高数百倍.它能够使因汞中毒而失活的脲酶恢复活力的能力优于巯基树脂及通用阴离子交换树脂。有可能作为口服的高分子解汞毒药物。     

STUDY ON THE SYNTHESIS OF POLYSTYRENESUPPORTED MACROCYCLIC MERCAPTAL CHELATING RESIN AND ITS PROPERTIES

Chelating resin with macrocyclic mercaptal group supported on macroporous polystyrene beads was synthesized, which showed good selectivity to Hg~(2+): its complexing capacity amounted to 30—60 mg Hg~(2+)/g resin, two orders of magnitude greater than for other metal ions such as Ca~(2+), Zn~(2+), Cd~(2+), Pb~(2+) etc. This resin could restore the activity of urease which had been deactivated by poisoning with Hg~(2+). Its restoring power was far better than that of the mercapto-resin and common anionic exchange resins. It showed some promising use as an oral polymeric detoxifying drug for mercury poisoning.     

BODIPY Immobilized MCM-41 Based Multianalyte Sensor: Application in Detection and Removal of Trivalent (Al3+, Cr3+) and Divalent (Cu2+, Hg2+) Metal Ions in Aqueous Media

In the present study, a novel p-phenylcarboxylic acid BODIPY ( L ) immobilized MCM-41 based solid chemosensor material L-propylsilyl@MCM-41 ( MS4 ) was developed to detect multiple metal ions in a pure aqueous medium. The synthesized solid chemosensor material MS4 shows high sensitivity and removal ability towards trivalent (Al³⁺, Cr³⁺) and divalent (Cu²⁺, Hg²⁺) metal ions. The emission intensity of MS4 enhanced multifold selectively in the presence of trivalent (Al³⁺, Cr³⁺) metal ions and shows quenching in the presence of divalent (Cu²⁺, Hg²⁺) metal ions. The limit of detection was calculated to be in the nanomolar range with Al³⁺, Cr³⁺, Cu²⁺_, and Hg²⁺ metal ions in the aqueous medium. The spectroscopic and analytical results suggest that MS4 selectively binds with Al³⁺ and Cr³⁺ through −NH functionality and with Hg²⁺ and Cu²⁺ through −COOH functionality of p-phenylcarboxylic acid BODIPY ( L ). Further, MS4 selectively removes Al³⁺, Cr³⁺, Cu²⁺, and Hg²⁺ metal ions from the aqueous media with removal efficiency of 97.28 %, 96.34 %, 87.19 %, and 95.63 %, respectively. No noticeable change in the concentration was observed for other metal ions. The recycling potential of MS4 was evaluated using EDTA for up to seven cycles with no significant reduction in sensing capability.     

螯合树脂研究 Ⅻ.以聚硫醚为主链的异丙巯基胺树脂的合成及其吸附性能

 由聚环硫氟丙烷与多乙烯多胺反应制得的聚合物(PB)再与环硫丙烷反应,合成了四种以聚硫醚为主链的异丙巯基胺树脂(PBM_1-4)。树脂对Au³⁺、Pd²⁺、Pt⁴⁺、Ag⁺和Hg²⁺等离子具有强的吸附能力,对Cu²⁺次之,对Zn²⁺和Pb²⁺很弱。树脂对贵金属具有高的选择性,能从含Au³⁺、Cr³⁺、Co²⁺、Ni²⁺、Cu²⁺、Mn²⁺、Zn²⁺和Fe³⁺的溶液中定量吸附Au³⁺而不吸附其它离子。     

Adsorption properties for metal ions of waste poly(p‐phenylene terephthalamide) fiber after chemical modification

Waste poly(p‐phenylene terephthalamide) fibers (PPTA) were chemically modified through nitration and nitro‐reduction reactions to obtain nitro‐ and amino‐containing fibers and used as adsorbents for metal ions. The structures of the modified fibers were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray diffraction (XRD), and thermogravimetric (TG) analysis. Metal ions, such as Ni²⁺, Pb²⁺, Cu²⁺, and Hg²⁺, were used to determine the adsorption capacities of the PPTA fibers before and after modification in aqueous solutions. The results showed that the modification improved the adsorption capability of fibers and extraction ratio of metal ions significantly. The adsorption mechanism of modified PPTA fibers for metal ions was proposed. The adsorption processes of Ni²⁺, Pb²⁺, and Cu²⁺ followed well a pseudosecond‐order model onto PPTA‐NH₂. The Langmuir and Freundlich models were employed to fit the isothermal adsorption. The results revealed that the linear Langmuir isotherm model is better‐fit model to predict the experimental data. Copyright © 2010 John Wiley & Sons, Ltd.     

螯合树脂研究——Ⅺ.一类新的氨基二硫代甲酸型螯合树脂的合成及吸附性能

 本文报道了以多乙烯多胺为主链的巯基胺树脂与二硫化碳反应,合成了四种新型的氨基二硫代甲酸型螯合树脂,这类树脂对贵金属具有高的吸附容量和优良的吸附选择性。并通过红外光谱和X光电子能谱研究树脂及其金属螫合物。     

Cysteine functionalized poly(hydroxyethyl methacrylate) monolith for heavy metal removal

The aim of this study was to investigate the performance of monoliths composed of hydroxyethyl methacrylate (HEMA) to which N-methacryloyl-(L)-cysteine methyl ester (MAC) was polymerized for removal of heavy metal ions. Poly(HEMA-MAC) monolith was produced by bulk polymerization. Poly(HEMA-MAC) monolith was characterized by FTIR and scanning electron microscopy (SEM). The poly(HEMA-MAC) monolith with a swelling ratio of 89%, and containing 69.4 μmol MAC/g were used in the adsorption studies. Adsorption capacity of the monolith for the metal ions, i.e., Cu²⁺, Cd²⁺, Zn²⁺, Hg²⁺, and Pb²⁺ were investigated in aqueous media containing different amounts of the ions (10–750 mg/L) and at different pH values (3.0–7.0). The maximum adsorption capacities of the poly(HEMA-MAC) monolith were 68.2 mg/g for Zn²⁺, 129.2 mg/g for Cu²⁺, 245.8 mg/g for Pb²⁺, 270.2 mg/g for Hg²⁺, and 284.0 mg/g for Cd²⁺. pH significantly affected the adsorption capacity of MAC incorporated monolith. The competitive adsorption capacities were 587 μmol/g for Zn²⁺, 1646 μmol/g for Cu²⁺, 687 μmol/g for Pb²⁺, 929 μmol/g for Hg²⁺, and 1993 μmol/g for Cd²⁺. The chelating monolith exhibited the following metal ion affinity sequence on molar basis: Cd²⁺ > Cu²⁺ > Hg²⁺ > Pb²⁺ > Zn²⁺. The formation constants of MAC–metal ion complexes have been investigated applying the method of Ruzic. The calculated values of stability constants were 5.28 × 10⁴ L/mol for Cd²⁺, 4.16 × 10⁴ L/mol for Cu²⁺, 2.27 × 10⁴ L/mol for Hg²⁺, 1.98 × 10⁴ L/mol for Pb²⁺, and 1.25 × 10⁴ L/mol for Zn²⁺. Stability constants were increased with increasing binding affinity. The chelating monoliths can be easily regenerated by 0.1 M HNO₃ with higher effectiveness. These features make poly(HEMA-MAC) monolith a potential adsorbent for heavy metal removal.