Synthesis and Adsorption Performance of Surface‐Grafted Co(II)‐Imprinted Polymer for Selective Removal of Cobalt

The surface‐grafting ion‐imprinting technology was applied to synthesis of a new Co(II)‐imprinted polymer [Co(II)‐IP], which could be used for selective removal of Co(II) from aqueous solutions. The prepared polymer was characterized by using the infrared spectra (IR), X‐ray diffractometer (XRD), X‐ray energy dispersion spectroscopy (EDS) and scanning electron microscopy (SEM). The maximum adsorption capacity values for the Co(II)‐imprinted polymer and non‐imprinted polymer (NIP) were 22 and 8 mg/g, respectively. The Freundlich equation fitted the adsorption isotherm data well. The applicability of two kinetic models including pseudo‐first‐order and pseudo‐second‐order models was estimated on the basis of comparative analysis of the corresponding rate parameters, equilibrium capacity, and correlation coefficients. Results suggested that chemical process could be the rate‐limiting step in the adsorption process. And the adsorption of Co(II) on the Co(II)‐imprinted polymer was endothermic. The relative selectivity coefficients of the Co(II)‐imprinted polymer for Co(II)/Pb(II), Co(II)/Cu(II), Co(II)/Ni(II), Co(II)/Sr(II) and Co(II)/Cs(I) were respectively 11.5, 6.1, 13.8, 9.4, and 8.1 times greater than that of the non‐imprinted polymer. Eventually, the desorption conditions of the adsorbed Co(II) from the Co(II)‐imprinted polymer were also studied in batch experiments.     

The resolution of α-amino acid by chiral polymer-copper complex

The (N-benzyl-l-leucinato) copper(II) complex was shown pH titration to coordinate l-amino acids more strongly than d enantiomers. A chiral polymer complex, containing N-alkylated amino acid residue and copper(II) ion, was used partially to resolve some optically active amino acids. Unlike the (N-benzyl-l-amino acidate)-copper(II) complex, the polymer—copper(II) complex coordinates d-amino acids more strongly than l-enantiomers; the effect was explained by formation of (N,N-dialkylated-amino acidate) copper(II) complex in the polymer.     

Side‐chain glycylglycine‐based polymer for simultaneous sensing and removal of copper(II) from aqueous medium

Since glycylglycine (Gly‐Gly) residue in the N‐terminal region of human prion protein, a copper binding protein, binds with Cu(II), N‐terminus Gly‐Gly side‐chain containing water soluble block copolymer was synthesized and used for simultaneous sensing and removal of Cu(II) ion from aqueous medium. The polymer has amide nitrogen atom and ester carbonyl group as potential binding sites in the side‐chain Gly‐Gly pendants. Job's plot experiment confirms 2:1 binding stoichiometry of polymer with Cu(II). This polymer is able to sense parts per billion level of Cu(II) very selectively in an aqueous medium and remove Cu(II) ions quantitatively by precipitating out the Cu(II) via complex formation in the pH range 7–9. The binding mode of polymer with Cu(II) in polymer‐Cu(II) complex was characterized by ¹H NMR, FTIR, and UV–vis spectroscopy. The attachment of Cu(II) in the polymer‐Cu(II) complex was confirmed by cyclic voltammetry experiment. Cu(II) release from the complex was achieved at pH 5 due to the protonation of amide nitrogen atoms in the Gly‐Gly moiety. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 914–921     

Copper Adsorption on Chitosan-Derived Schiff Bases

The adsorption of Cu(II) ions onto the chitosan derived Schiff bases obtained from the condensation of chitosan with salicyaldehyde (polymer I), 2,4-dihydroxybenzaldehyde (polymer II) and with 4-(diethylamino) salicyaldehyde (polymer III) in aqueous solutions was investigated. Batch adsorption experiments were carried out as a function of contact time, pH, and polymer mass. The amount of metal-ion uptake of the polymers was determined by using atomic absorption spectrometry (AAS) and the highest Cu(II) ions uptake was achieved at pH 7.0 and by using sodium perchlorate as an ionic strength adjuster for polymers I, II, and III. The isothermal behavior and the kinetics of adsorption of Cu(II) ions on these polymers with respect to the initial mass of the polymer and temperature were also investigated; adsorption isothermal equilibrium data could be clearly explained by the Langmuir equation. The experimental data of the adsorption equilibrium from Cu(II) solution correlates well with the Langmuir isotherm equation.     

Fe(II)-脱乙酰壳聚糖配位聚合物的合成及其性能表征

本文探讨了壳聚糖对Fe(Ⅱ）的吸附条件，并对壳聚糖与Fe(Ⅱ)的吸附行为进行了详细研究，认为Fe(Ⅱ)与壳聚糖既发生配位反应形成Fe(Ⅱ)-壳聚糖配位聚合物，也产生吸附作用，并通过红外光谱和紫外光谱证实了Fe(Ⅱ)与壳聚糖之间发生了配位作用。     

Polymer supported catalysts for oxidation of phenol and cyclohexene using hydrogen peroxide as oxidant

Polymer supported transition metal complexes of N,N′-bis (o-hydroxy acetophenone) hydrazine (HPHZ) Schiff base were prepared by anchoring its amino derivative Schiff base (AHPHZ) on cross-linked (6 wt%) polymer beads and then loading iron(III), copper(II) and zinc(II) ions in methanol. The loading of HPHZ Schiff base on polymer beads was 3.436 mmol g⁻¹ and efficiency of complexation of polymer anchored HPHZ Schiff base for iron(III), copper(II) and zinc(II) ions was 83.21, 83.40 and 83.17%, respectively. The efficiency of complexation of unsupported HPHZ Schiff base for these metal ions was lower than polymer supported HPHZ Schiff base. The structural information obtained by spectral, magnetic and elemental analysis has suggested octahedral and square planar geometry for iron(III) and copper(II) ions complexes, respectively, with paramagnetic behavior, but zinc(II) ions complexes were tetrahedral in shape with diamagnetic behavior. The complexation with metal ions has increased thermal stability of polymer anchored HPHZ Schiff base. The catalytic activity of unsupported and polymer supported HPHZ Schiff base complexes of metal ions was evaluated by studying the oxidation of phenol (Ph) and epoxidation of cyclohexene (CH). The polymer supported metal complexes showed better catalytic activity than unsupported metal complexes. The catalytic activity of metal complexes was optimum at a molar ratio of 1:1:1 of substrate to oxidant and catalyst. The selectivity for catechol (CTL) and epoxy cyclohexane (ECH) in oxidation of phenol and epoxidation of cyclohexene was better with polymer supported metal complexes in comparison to unsupported metal complexes. The energy of activation for oxidation of phenol (22.8 kJ mol⁻¹) and epoxidation of cyclohexene (8.9 kJ mol⁻¹) was lowest with polymer supported complexes of iron(III) ions than polymer supported Schiff base complexes of copper(II) and zinc(II) ions.     

Cu(II)-脱乙酰壳聚糖配位聚合物的配位数

IR,ESR和XPS的测试结果表明,脱乙酰壳聚糖(简记CS)膜在铜氨水溶液浸渍过程中Cu(II)既与CS发生配位反应形成Cu(II)-CS配位聚合物,也产生吸附作用。ESR谱示出CuCl~2.2H~2O与Cu(II)-CS膜中的Cu(II)均含有一个单电子,可以利用XPS的Shake-up效应研究Cu(II)-CS配位聚合物的配位数,所得结果为4。又以同样的方法研究Cu(II)-聚乙烯醇(简记PVA)配位聚合物的配位数,发现Cu(II)是以低自旋状态的dsp^2杂化空轨道与PVA的羟基氧配位,其配位数也是4,这与资料所报道的一致,从而间接地验证了此方法研究Cu(II)-CS配位聚合物配位数的可靠性。     

Preparation of novel polymer ligands containing tetraaza macrocyclic schiff base as a highly selective extractant for copper(II)

Three types of the novel polymer ligands in which 6,8,15,17-tetramethyl-dibenzo-5,9,14,18-tetraaza-cyclotetradecene (L) is present as an integral part of the polymer backbone have been prepared. These polymer ligands are oligomers whose polymerization degree may be about five. Their complexing abilities and extractabilities for copper(II) and nickel(II) have been investigated. Among the polymer ligands, Poly-L3, which contains triethyleneglycol bis(p-phenylene) group as a linkage group, was found to be an excellent extractant for copper(II).     

Specific mercury(II) adsorption by thymine-based sorbent

A new kind of polymer sorbent based on the specific interaction of Hg(II) with nucleic acid base, thymine, is described for the selective adsorption of Hg(II) from aqueous solution. Two types of sorbents immobilized with thymine were prepared by one-step swelling and polymerization and graft polymerization, respectively. The maximum static adsorption capacity of the new polymer sorbents for Hg(II) is proportional to the density of thymine on their surface, up to 200 mg/g. Moreover, the new kind polymer sorbent shows excellent selectivity for Hg(II) over other interfering ions, such as Cu(II), Cd(II), Zn(II), Co(II), Ca(II) and Mg(II), exhibits very fast kinetics for Hg(II) adsorption from aqueous solution, and can be easily regenerated by 1.0 M HCl. It also has been successfully used for the selective adsorption of spiked Hg(II) from real tap water samples. This new thymine polymer sorbent holds a great promise in laboratory and industrial applications such as separation, on-line enrichment, solid-phase extraction, and removal of Hg(II) from pharmaceutical, food and environmental samples.     

Adsorption of mercury(II) on macroreticular styrene-divinylbenzene copolymer beads

The adsorption characteristics of mercury(II) on several kinds of styrene-divinylbenzene copolymer beads having different surface properties were studied. It was found that the polymer beads selectively adsorbed mercury(II) from solutions over a wide range of pH with high efficiency. The amount of mercury(II) adsorbed increased with increase in specific surface area of the polymer beads and the adsorption behaviour was found to be of the Langmuir type. The presence of chloride strongly reduced the adsorption, but this interference was not observed with nitrate, sulphate, perchlorate, cadmium(II), cobalt(II), copper(II), nickel(II), silver(I) and zinc(II). More than 95% of the mercury(II) adsorbed on a column of polymer beads could be recovered with dilute hydrochloric acid.     

Cu(Ⅱ)脱乙酰壳聚精配位聚合物的配位数

IR,ESR和XPS的测试结果表明,脱乙酰壳聚糖(简记CS)膜在铜氨水溶液浸渍过程中Cu(Ⅱ)既与CS发生配位反应形成Cu(Ⅱ)-CS配位聚合物,也产生吸附作用.ESR谱示出CuCl_2·2H_2O与Cu(Ⅱ)-CS膜中的Cu(Ⅱ)均含有一个单电子,可以利用XPS的Shake-up效应研究Cu(Ⅱ)-CS配位聚合物的配位数,所得结果为4.又以同样的方法研究Cu(Ⅱ)-聚乙烯醇(简记PVA)配位聚合物的配位数,发现Cu(Ⅱ)是以低自旋状态的dsp~2杂化空轨道与PVA的羟基氧配位,其配位数也是4,这与资料所报道的一致,从而间接地验证了此方法研究Cu(Ⅱ)-CS配位聚合物配位数的可靠性.     

SYNTHESIS, CHARACTERIZATION AND CATALYTIC ACTIVITY OF N,N''-BIS(3-ALLYL SALICYLIDENE)ETHYLENEDIAMINE COBALT(II) SCHIFF BASE COMPLEX ANCHORED ON A NEW POLYMER SUPPORT

A new chelating polymer support has been prepared by suspension copolymeriz a tion of synthesized N,N'-bis(3-allyl salicylidene)ethylenediamine monomer Schiff base (N,N'-BSEDA) with styrene (St) and divinylbenzene (DVB) using azobisisobutyronitrile (AIBN) as initiator in the presence of poly(vinyl alcohol). The content and complexation ability of monomer Schiff base (N,N'-BSEDA) for cobalt(II) ions in prepared crosslinked polymer beads have shown dependence on the amount of DVB used in reaction mixture. The amount of monomer Schiff base (N,N'-BSEDA) in crosslinked beads showed a substantial decreasing trend at high concentration of DVB in the reaction mixture (＞ 1.5 mol dm-3), hence the efficiency of complexation (EC%) and cobalt(II) ion loading (EL%) of polymer beads showed a decreasing trend. The structure of monomer Schiff base (N,N'-BSEDA) and its cobalt(II) complex on polymer support was elucidated by IR, UV and magnetic measurements. The catalytic activity of polymer bound cobalt(Ⅱ) Schiff base complex was evaluated by analyzing kinetic data of decomposition of hydrogen peroxide in the presence of either supported cobalt (II) complex or free cobalt(II) complex. The activation energy for the decomposition of hydrogen peroxide by polymer supported cobalt(II)complex was found to be low (33.37 kJ mol-l) in comparison with unsupported cobalt(II) complex (56.35 kJ mol-1). On the basis of experimental observations, reaction steps are proposed and a suitable rate expression derived.     

Preparation,characterization and thermal stability of poly[2-(Dimethylamino)ethyl acrylate]

Poly[2-(dimethylamino)ethyl acrylate] (PDAEA) and polymer complexes of 2-(dimethylamino)ethyl acrylate (DAEA) with nickel(II), copper(II), iron(III) and cobalt(II) chlorides were prepared and characterized by means of IR, electronic spectra and elemental analysis. The thermal stability of the homopolymer was compared with those of the polymer complexes, and the order of stability was given. The activation energies of the polymer complexes were calculated.     

Design and development of several polymeric metal–organic frameworks,spectral characterization,and their antimicrobial activity

Coordination polymers were obtained by the reaction of metal acetates, M(CH₃COO)₂·xH₂O {where M = Mn(II), Co(II), Ni(II) and Cu(II)} with AFP ligand (AFP = 5,5'-(piperazine-1,4-diylbis(methylene))bis(2-aminobenzoic acid). The AFP ligand was prepared by the one-pot, two-step reaction of formaldehyde, 2-aminobenzoic acid, and piperazine. Structural and spectroscopic properties have been studied by elemental, spectral (FT-IR, ¹H NMR, ¹³C NMR, and UV–vis), and thermogravimetric analysis. UV–vis spectra and magnetic moment values indicate that Mn(II), Co(II), and Ni(II) polymer–metal complexes are octahedral, while Cu(II) and Zn(II) polymer–metal complexes are distorted octahedral and tetrahedral, respectively. The analytical data confirmed that the coordination polymers of Mn(II), Co(II), Ni(II), and Cu(II) are coordinated with two water molecules, which are further supported by infrared spectra and thermogravimetric analysis data. The prepared polymer–metal complexes showed good antibacterial activities against all tested microorganisms; however, the AFP ligand was also found to be effective, but relatively less than their polymer–metal complexes. Along with antibacterial activity, all the polymer–metal complexes exhibit significant antifungal activity against most of the tested fungal strains. The results of antimicrobial activity reveals that the AFP–Cu(II) showed the highest antibacterial and antifungal activity than other polymer–metal complexes.     

Transition metal complexes of poly(vinylpyridines)

The structures of the precipitates of free-radical poly(4-vinylpyridine) (Vpy), free-radical poly(2-Vpy) and isotactic poly(2-Vpy) with M(II)Cl₂ (M = Co, Ni, Cu, Zn) obtained from solution have been investigated. The polymer compounds are similar to the known crystalline monomeric Vpy complexes and, with one exception, are crosslinked by the metal dichloride. Co(II) and Zn(II) are tetrahedrally coordinated by the polymer, while the Ni(II) and Cu(II) complexes are probably tetrahedral and square-planar, respectively. Because of the constraints of the polymeric ligands the stoichiometries of the complexes are not exactly the same as those of the monomeric Vpy complexes and from one to two Vpy units per metal halide are on average not coordinated. Atactic and isotactic poly(2-Vpy) showed marked differences with regard to coordination of Ni(II). The questions of stereochemistry of the coordinated metal ion, stoichiometry of the complexes, intermolecular versus intramolecular complexation of the polymer chain, and the influence of polymer tacticity on the crystallizability of polymer complexes are discussed.     

Viscoelastic behavior and phase domain formation in Millar interpenetrating polymer networks of polystyrene

Millar-type interpenetrating polymer networks (IPNs) are composed of two identical networks. In the present case Millar IPNs of polystyrene/polystyrene were prepared where the crosslinker levels of the two networks differed by a factor of 10. Polymer network I contained 0.4% divinylbenzene (DVB) and polymer network II contained 4% DVB, the polymers having the following weight proportions: 75/25, 50/50, and 25/75. A single polystyrene network containing 2.2% DVB was synthesized for comparison with the 50/50 Millar IPN, both containing the same average amount of crosslinker. The creep behavior of the Millar IPNs was found to be dominated by polymer network I, as were the rubbery moduli and swelling behavior in toluene. These results suggested that polymer I domains are more continuous in space and polymer II domains are less continuous. The Donatelli equation predicted polymer II domain sizes of 60 Å to 100 Å for the Millar IPNs. Electron micrographs of specimens containing 1% isoprene in polymer II offered visual evidence for the segregation of polymer II domains from polymer I, and showed that the polymer II domains were, in fact, less continuous. Polymer II domains varied from about 50 to 100 Å in size, as predicted. These results have implications for gelation processes in general.     

Simple Conjugated Polymers with On‐Chain Phosphorescent Iridium(III) Complexes: Toward Ratiometric Chemodosimeters for Detecting Trace Amounts of Mercury(II)

For the development of excellent optical probes for mercury(II), a series of simple conjugated polymers that contain phosphorescent iridium(III) complexes as receptors for mercury(II) were designed and synthesized. These conjugated polymers showed energy transfer from the polymer host to iridium(III) complex guest in both solution and the solid state. Unexpectedly, they can work as excellent polymer chemodosimeters for mercury(II) by utilizing the mercury(II)‐induced decomposition of iridium(III) complex. They exhibit a pronounced optical signal change with switchable phosphorescence and fluorescence, even when the concentration of a solution of mercury(II) in THF was as low as 0.5 ppb. With the addition of mercury(II), the phosphorescent emission intensity of iridium(III) complexes was quenched completely. As the emission from polymer backbones increased, the emission wavelength was redshifted simultaneously, thereby realizing ratiometric detection. Excellent selectivity toward mercury(II) over other potentially interfering cations was also realized. In addition, an obvious emission color change of polymer solution from red to yellow‐green was observed, thus realizing a “naked‐eye” detection of mercury(II). More importantly, the solid films of these polymer chemodosimeters also exhibited high sensitivity and rapid response to mercury(II), thereby demonstrating the possibility of the fabrication of sensing devices with fast and convenient detection of mercury(II). The sensing mechanism was also investigated in detail. This is the first report on chemodosimeters based on conjugated polymers with phosphorescent iridium(III) complexes.     

Solid phase extraction and determination of metal ions in aqueous samples using Quercetin modified Amberlite XAD-16 chelating polymer as metal extractant

A new chelating polymer has been developed using Amberlite XAD-16 anchored with Quercetin. The modified polymer was characterised by Fourier Transform Infra Red (FTIR) spectroscopy, thermogravimetric analysis, surface area analysis and elemental analysis. The Quercetin anchored polymer showed superior binding affinity for Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) with greater than 95% adsorption under optimum conditions. The optimum pH conditions for the quantitative sorption of metal ions were studied. The developed method showed superior extraction qualities with high metal loading capacities of 387, 313, 195, 473, 210 and 320 µmol g^?1 for Cu(II), Co(II), Cr(III), Fe(III), Mn(II) and Ni(II), respectively. The rate of metal ion uptake i.e. kinetics studies performed under optimum levels, showed t _1/2 for Co(II), Cu(II), Cr(III), Fe(III), Mn(II) and Ni(II) is 20, 15, 25, 10, 30 and 15 min, respectively. Desorption of metal ions was effective with 10 mL of 2 M HCl prior to analysis using flame atomic absorption spectrophotometer. The chelating polymer was highly ion selective in nature even in the presence of interferent ions, with a high preconcentrating ability for the metal ions of interest. The developed chelating polymer was tested on its utility with synthetic and real samples like river, tap water samples and also with multivitamin tablets. It showed relative standard deviation (R.S.D.) values of/less than 3.0% reflecting on the accuracy and reproducibility of data using the newly developed chelating polymer.     

Preparation, spectral and biological investigation of formaldehyde-based ligand containing piperazine moiety and its various polymer metal complexes

A novel tetradentate salicylic acid-formaldehyde ligand containing piperazine moiety (SFP) was synthesized by condensation of salicylic acid, formaldehyde and piperazine in presence of base catalyst, which was subjected for the preparation of coordination polymers with metal ions like manganese(II), cobalt(II), copper(II), nickel(II) and zinc(II). All the synthesized polymeric compounds were characterized by elemental analysis, IR, (1)H NMR and electronic spectral studies. The thermal stability was determined by thermogravimetric analysis and thermal data revealed that all the polymer metal complexes show good thermal stability than their parent ligand. Electronic spectral data and magnetic moment values revealed that polymer metal complexes of Mn(II), Co(II) and Ni(II) show an octahedral geometry while Cu(II) and Zn(II) show distorted octahedral and tetrahedral geometry respectively. The antimicrobial screening of the ligand and coordination polymers was done by using Agar well diffusion method against various bacteria and fungi. It was evident from the data that antibacterial and antifungal activity increased on chelation and all the polymer metal complexes show excellent antimicrobial activity than their parent ligand.     

Electrochemical Polymerization of Ni(II) and Pd(II) Complexes with 1,2-Bis(o-aminobenzylidene)ethylenediamine

Polymers based on the Pd(II) and Ni(II) complexes with 1,2-bis(o-aminobenzylidene)ethylenediamine and exhibiting conducting properties are synthesized. The kinetic regularities of polymer formation on solid substrates and dependence of the rate of charge diffusion in a bulk of polymer matrix on the polymer thickness are established.