Hyperbranch-polyethyleniminated functional polymers II: effect of polyethyleniminated polyoxypropylenediamines on copper nanoparticle formation in aqueous solution

Colloidal aqueous solution of zerovalent copper (Cu(0)) nanoparticles were prepared from the Cu²⁺ ions coordinated with polyethyleniminated polyoxypropylenediamines (D400(EI) _x ) followed by chemical reduction of NaBH₄. Aqueous solution of copper clusters formed in the presence of D400(EI)₈ with a loading ratio of [EI]/[Cu²⁺] = 3 were stable without precipitation for standing more than 1 month. The protective effects of D400(EI) _x and the particle size of the resulted Cu nanoparticle are regulated by the attachments of ethylenimine (EI) groups per polymer backbone and the normality ratio of [EI]/[Cu²⁺] used. It is found that the more EI-content per polymer backbone results in the smaller particle size and the narrower size dispersity of the colloidal Cu(0) particles, and the average particle size of 5.07 nm with standard deviation of 0.86 nm was obtained in the presence of D400(EI)₈ with the ratio of [EI]/[Cu²⁺] = 3. As the polymer concentration of D400(EI)₈ increases (the increase of [EI]/[Cu²⁺]), the average particle size of the prepared Cu(0) nanoparticle slightly changes, but interestingly, the size dispersity gradually decreases, where the standard deviation for the concentration at [EI]/[Cu²⁺] = 5 is 0.82 nm approaching that for monodispersed nanoparticles (0.5 nm).     

Synthesis of phenanthroline‐terminated polymers and their Fe(II)‐complexes

Well‐defined mono‐ and bifunctional, phenanthroline‐terminated poly(ethylene glycol) and polyisobutylene capable of polymer network formation were synthesized. The starting materials mono‐ and bi‐phenanthroline‐ (phen) terminated poly(ethylene glycols) (mPEG‐phen, phen‐PEG‐phen) and polyisobutylenes (PIB‐phen, phen‐PIB‐phen) were prepared by the Williamson synthesis and characterized by means of ¹H NMR and MALDI‐TOF mass spectrometry. According to UV–Vis spectrophotometry and ESI‐TOF mass spectrometry, the phenanthroline‐terminated polymers underwent quantitative complex formation with ferrous ions in solution. The aqueous solution of mPEG‐phen shows self‐assembly behavior. Important parameters, such as critical micelle concentration and hydrodynamic radius of the aggregates were also determined. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2709–2715, 2010     

Synthesis and photoproperties of Eu(III)‐bearing star polymers as luminescent materials

Water‐soluble luminescent material was developed by introducing europium (Eu(III)) ions into the core of a star polymer. Living radical polymerization was used to obtain the star polymer. The strategy to introduce Eu(III) ions into the star polymer was studied using poly(methyl methacrylate) as an arm. The best Eu(III) ion introduction was obtained by simultaneous introduction, resulting in about 30 µmol/g‐polymer, which needed only one step for synthesis. The utilization of a hydrophilic polymer such as poly(ethylene oxide) (PEO) as an arm produced a water‐soluble star polymer. The Eu(III)‐bearing PEO star polymer obtained in this study was water soluble and showed fluorescence. In addition, it was stable in water after 1 month. The Eu(III)‐bearing star polymer exhibited luminescent properties under UV light irradiation with relatively high quantum yields of 60% in organic solution and 19% in aqueous solution. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2527–2535     

Synthesis of imidazole‐terminated hyperbranched polymers with POSS‐branching points and their pH responsive and coordination properties

An imidazole‐terminated hyperbranched polymer with octafunctional POSS branching units denoted as POSS‐HYPAM‐Im was prepared by the polymerization of excess amounts of tris(2‐aminoethyl)amine with the first‐generation methyl ester‐terminated POSS‐core poly(amidoamine)‐typed dendrimer, reacting with methyl acrylate, and ester‐amide exchange reaction with 3‐aminopropylimidazole. The imidazole‐terminated hyperbranched poly(amidoamine) denoted as HYPAM‐Im was also synthesized with 1‐(3‐aminopropyl)imidazole from a methyl ester‐terminated hyperbranched poly(amidoamine) by the ester‐amide exchange reaction. The transmittance of the POSS‐HYPAM‐Im solution drastically decreased when the solution pH was greater than 8.2. On the other hand, the transmittance of the HYPAM‐Im solution gradually decreased when the solution pH at 8.5 and was greater than 9. Spectrophotometric titrations of the hyperbranched polymer aqueous solutions with Cu²⁺ ions indicated the variation of the coordination modes of POSS‐HYPAM‐Im from the Cu²⁺–N₄ complex to the Cu²⁺–N₂O₂ complex and the existence of the only one complexation mode of Cu²⁺–N₄ between Cu²⁺ ion and HYPAM‐Im with increasing the concentrations. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2695–2701     

Synthesis and characterization of water‐soluble barbiturate‐ and thiobarbiturate‐functionalized polystyrene

The synthesis and characterization of barbiturate‐ and thiobarbiturate‐functionalized polystyrene from polystyrene homopolymer by polymer‐modification reactions is discussed. Polystyrene homopolymer quantitatively functionalized at the para postion with diethyl oxomalonate functionality was subjected to a condensation reaction with urea and thiourea in the presence of sodium methoxide in methanol. This reaction proceeded essentially to quantitative conversion to the barbiturate‐ (BAPS) and thiobarbiturate‐functionalized polystyrenes (TBAPS) as estimated by ¹H NMR, UV, and IR spectroscopies. Thus, several copolymers of styrene with barbiturate‐ and thiobarbiturate‐functionalized styrene were synthesized. The detailed characterizations of quantitatively functionalized polystyrene using gel permeation chromatographic, IR, UV, and ¹H NMR spectroscopic techniques as well as thermogravimetric analysis are discussed. An application of the newly synthesized polymer in removing Cu(II) ions from aqueous solution is demonstrated. This is the first report on the synthesis of BAPS and TBAPS by the polymer‐modification route or otherwise. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 731–737, 2002; DOI 10.1002/pola.10154     

Terpyridine‐substituted,fluorescent polymers and their chelation with zinc ion: The ligand‐to‐metal ratio and optical properties

Soluble, fluorescent, terpyridine‐substituted, conjugated polymers were prepared and characterized. The polymer chains included a defined oligo(phenylenevinylene) fragment, on which the terpyridine‐functional group was attached. The polymers were blue‐fluorescent with emission peaks at 400–427 nm in tetrahydrofuran solutions. Upon chelation with the Zn(II) cation, the emission maxima were shifted to a longer wavelength by as much as 113 to 506–526 nm. A model compound was also prepared to aid the structural characterization. The ratio of terpyridine to Zn²⁺ in the polymer complex was found to be 1:1 on the basis of spectroscopic evidence, which included mass spectrometry, ¹H NMR, and Job titration. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2338–2345, 2006     

Comparative study of electrostatic binding vs. complexation of Cu2+ ions with water‐soluble polymers containing styrene sulphonic acid and/or maleic acid units or their sodium salt forms

The interaction of Cu²⁺ ions with the homopolymer poly(styrene sulfonic acid) (PSSH), as well as with the copolymers of maleic acid (MAc) with styrene sulfonic acid (SSH) or vinyl acetate (VAc), was investigated in dilute aqueous solution through turbidimetry, potentiometry, viscometry, and spectrophotometry in the visible region. Cu²⁺ ions were introduced either through neutralization with Cu(OH)₂ of the acid form of the (co)polymers (PSSH, P(SSH‐co‐MAc) and P(VAc‐co‐MAc)) or through mixing of the sodium salt form of the (co)polymers (PSSNa, P(SSNa‐co‐MANa) and P(VAc‐co‐MANa)) with CuSO₄. Turbidimetry, potentiometry, and spectrophotometry revealed that the first carboxylic group of MAc or both carboxylate groups of MANa are involved in the complexation with Cu²⁺ ions when neutralization with Cu(OH)₂ or mixing with CuSO₄ are applied, respectively. The increased values of the reduced viscosity observed mainly at the first stages of neutralization of P(VAc‐co‐MAc) with Cu(OH)₂ indicate that interchain polymer‐Cu²⁺ complexation takes possibly place. Finally, the spectrophotometric behavior observed upon neutralization of P(SSH‐co‐MAc) with Cu(OH)₂ or mixing of P(SSNa‐co‐MANa) with CuSO₄ revealed that the strength of counterion binding by the sulfonate groups is, in fact, comparable with the complexation of Cu²⁺ ions with the carboxylate groups of MAc. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1149–1158, 2008     

Synthesis of new Azo‐based liquid crystalline polymers and their selective sensing behaviors to alkali metal ions

We report novel liquid crystalline (LC) polymers containing pendant azobenzene moieties with n‐dodecyl substituents and ethyleneoxy spacers of different lengths and describe their selective detection behaviors to alkali metal ions. The new azopolymers produce homogenous smectic phases with a typical fan‐shaped texture. UV‐Vis and ¹H NMR studies confirm that the azopolymers selectively bind to Li⁺ and Na⁺, but do not complex with K⁺, Ba²⁺, Mg²⁺, or Ca²⁺. Both the ethyleneoxy spacer and azobenzene units participate in binding to Li⁺ and Na⁺ cations in solution. Interestingly, after formation of the complexed structure, the ratio of cis to trans conformer is considerably increased suggesting stronger interactions of the cis conformer with alkali metal ions. Irradiation of the complexed structure with 365 nm UV induces conversion of the uncomplexed trans to the cis. These findings suggest a great potential of the LC azopolymers as selective sensors or separation membranes for alkali metal ions. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1713–1723     

Synthesis,characterization, and ion‐complexing properties of polymers displaying densely packed arrays of crown‐ethers as lateral substituents

We report the synthesis and ion‐binding properties of four poly(crown‐ethers) displaying either one or two crown‐ethers (15‐crown‐5 or 18‐crown‐6) on every third carbon alongside the backbone. The polymers were synthesized by living anionic ring‐opening polymerization of disubstituted cyclopropane‐1,1‐dicarboxylates monomers. Cation binding of the polychelating polymers and corresponding monomers to Na⁺ and K⁺ was evaluated by picrate extraction and isothermal calorimetry titration. This novel family of poly(crown‐ethers) demonstrated excellent initial binding of the alkali ions to the polymers, with a higher selectivity for potassium. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2337–2345     

Poly(N‐phenylmaleimide‐co‐acrylic acid)–copper(II) and poly(N‐phenylmaleimide‐co‐acrylic acid)–cobalt(II) complexes: Synthesis,characterization, and thermal behavior

The free‐radical copolymerization of N‐phenylmaleimide (N‐PhMI) with acrylic acid was studied in the range of 25–75 mol % in the feed. The interactions of these copolymers with Cu(II) and Co(II) ions were investigated as a function of the pH and copolymer composition by the use of the ultrafiltration technique. The maximum retention capacity of the copolymers for Co(II) and Cu(II) ions varied from 200 to 250 mg/g and from 210 to 300 mg/g, respectively. The copolymers and polymer–metal complexes of divalent transition‐metal ions were characterized by elemental analysis, Fourier transform infrared, ¹H NMR spectroscopy, and cyclic voltammetry. The thermal behavior was investigated with differential scanning calorimetry (DSC) and thermogravimetry (TG). The TG and DSC measurements showed an increase in the glass‐transition temperature (T_g) and the thermal stability with an increase in the N‐PhMI concentration in the copolymers. T_g of poly(N‐PhMI‐co‐AA) with copolymer composition 46.5:53.5 mol % was found at 251 °C, and it decreased when the complexes of Co(II) and Cu(II) at pHs 3–7 were formed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4933–4941, 2005     

Ru(II)(tpy)2‐functionalized hydrogels: Synthesis,reversible responsiveness,and coupling with the belousov‐zhabotinsky reaction

This work aims at developing an approach to Ru(II)(Tpy)₂‐functionalized hydrogels and exploring the coupling of the hydrogels with the Belousov‐Zhabotinsky (BZ) reaction. Based on free radical polymerization, two synthetic routes are developed. The first one is the direct gelation by copolymerization of acrylamide as hydrophilic component and Ru(II)(Tpy)₂ as the functional group. The second one is carried out through a combined approach. A terpyridine‐containing hydrogel is first prepared and then post‐functionalized by coordination between Ru(III)(Tpy)Cl₃ and terpyridine groups in the hydrogel network. Utilizing the synthetic hydrogels, the reversible redox responsiveness, the coupling with the BZ reaction, the occurrence and the self‐oscillating properties of the BZ reaction in the hydrogel networks are studied. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2214–2222     

Water‐soluble conjugated polymers: Synthesis and optical properties

Two sets of water‐soluble poly(phenylene vinylene)s were synthesized and their optical properties were studied. The aqueous solubility of all these polymers is rendered by pendant sulfonate groups. One set of polymers (polymer I series) contains, in addition to the sulfonate pendants, dimethoxy substituents, while the other (polymer II series) contains oligo(ethylene oxide) side chains. Within each set, polymers containing lithium (Ia and IIa), sodium (Ib and IIb), and potassium (Ic and IIc) counter ions were prepared. The two sets of polymers showed different properties from physical appearance (fiber vs film) to thermal properties and to optical properties. It was found that set I polymers, with shorter side chains, exhibit stronger aggregation in aqueous solutions than set II polymers, which led to their lower fluorescence quantum yields and lower polymer‐to‐MV²⁺ quenching efficiencies. Within each set, the effect of counter ions on optical properties was noted. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5123–5135, 2007     

Synthesis and properties in solution of ruthenium(II) coordination polymers

Synthetic strategies are presented for the preparation of readily soluble ruthenium(II) coordination polymers of high molecular weight. The constitutional homogeneity of the polymers is proved using high-resolution NMR spectroscopy, and their molar masses are estimated from ¹H NMR spectra, viscosity data and SAXS investigations. The polymers are shown to be conformationally rigid, and to form either densely packed coils or rods. It is mainly this difference in shape which causes the very specific properties of the respective polyelectrolytes in the solid state as well as in dilute solution. Finally, the UV-vis absorption spectra of some of these materials are presented.     

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     

Oligosaccharide-modified poly(propyleneimine) dendrimers: synthesis, structure determination, and Cu(II) complexation

The multiple application of reductive amination on primary amino groups of first and second generation poly(propyleneimine) dendrimers is used as a one-pot approach to introduce twice the amount of the oligosaccharide units as surface groups, compared to initially present amino groups in the first and second generation dendrimers. This was proven by (1)H NMR, MALDI-TOF-MS, and LILBID-MS analysis. The size of these dendrimers was determined by the hydrodynamic radius using pulsed field gradient NMR and dynamic light scattering. Molecular modeling confirmed the presence of dense-shell dendrimers. These dendrimers exhibit a generation dependent Cu(II)/dendrimer ratio in an aqueous environment, highlighting these materials as possible metal-carrier systems with a well-defined oligosaccharide protection shell for application in a biological environment.     

Polymerization of acrylamide photoinitiated by tris(2,2′‐bipyridine)ruthenium(II)–amine in aqueous solution: Effect of the amine structure

The photopolymerization of acrylamide (AA) initiated by the metallic complex tris(2,2′‐bipyridine)ruthenium(II) [Ru(bpy)₃⁺²] in the presence of aliphatic and aromatic amines as co‐initiators was investigated in aqueous solution. Aromatic amines, which are good quenchers of the emission of the metal‐to‐ligand‐charge‐transfer excited state of the complex, are more effective co‐initiators than those that do not quench the luminescence of Ru(bpy)₃⁺², such as aliphatic amines and aniline. Laser‐flash photolysis experiments show the presence of the reduced form of the complex, Ru(bpy)₃⁺¹, for all the amines investigated. For aliphatic amines, the yield of Ru(bpy)₃⁺¹ increases with temperature, and on the basis of these experiments, a metal‐centered excited state is proposed as the reactive intermediate in the reaction with these amines. The decay of the transient Ru(bpy)₃⁺¹ is faster in the presence of AA. This may be understood by an electron‐transfer process from Ru(bpy)₃⁺¹ to AA, regenerating Ru(bpy)₃⁺² and producing the radical anion of AA. It is proposed that this radical anion protonates in a fast process to give the neutral AA radical, initiating in this way the polymerization chain. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4265–4273, 2001     

Coordination of nickel and copper dithiolate to 2,2′‐bipyridine‐based π‐conjugated polymers

π‐Conjugated polymers (Poly1–Poly3) containing a 2,2′‐bipyridine (bpy) unit were subjected to coordination to nickel and copper dithiolate for the purpose of manipulating the photophysical properties. The absorption maximum peak of Poly1 [maximum wavelength (λ_max) = 446 nm] redshifted by 36 nm upon the coordination of bpy to NiCl₂, which produced Poly1–NiCl₂. A further bathochromic shift was observed in the spectrum of Poly1–mntNi [mntNi = (maleonitrile dithiolate)nickel; λ_max = 499 nm] bearing the dithiolate ligand, which stemmed from the extension of the conjugated system over the nickel dithiolate moiety through the bpy unit. An increase in the [Ni]/[bpy] ratio in Poly1–mntNi rendered the original maximum peak at 446 nm smaller and the lower energy charge‐transfer peak at 499 nm larger; the isosbestic points remained at 380 and 475 nm. The green fluorescence (λ_max = 504 nm) emitted from Poly1 markedly diminished upon the coordination of nickel dithiolate because of the effective energy transfer. The absorption maximum peak of Poly1–mntNi in chloroform at 499 nm blueshifted to 471 nm when the volume ratio of the chloroform/N,N‐dimethylformamide solvent reached 10:90. The coordination of nickel dithiolate to Poly2 and Poly3 also brought about redshifts of the absorption maximum peaks of as much as 55 and 61 nm, respectively. The absorption maximum peak of Poly1–(phenyldithiolate)nickel(pdtNi) (λ_max = 474 nm) redshifted by 28 nm in comparison with that of Poly1, whereas the magnitude of the shift of Poly1–bis(thiophenoxide)nickel(btpNi) bearing two thiophenoxide ligands was 20 nm. Poly1–mntCu with a tetrahedral copper center was also investigated. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2631–2639, 2004     

Complex formation of polyethyleneimine with copper(II), nickel(II), and cobalt(II) ions

An influence of the structure of a globule of polyethyleneimine on the complex formation of one with the copper(II), nickel(II), and cobalt(II) ions is described. A change of the coordination number from the pH of solution for complexes of ethylenediamine, diethylenetriamine, and polyethyleneimine with metal ions was found. The fraction of monomer links, bound with metal ions, depends on the volume of the globule of macromolecule as well as the condition of the proceeding reaction. The reaction of complex formation is controlled by the diffusion of metal ions into the polymer globule in solution. The effective equilibrium constants of complex formation were found. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 914–922, 2002; DOI 10.1002/pola.10157     

Synthesis of poly(ester‐amide) dendrimers based on 2,2‐Bis(hydroxymethyl) propanoic acid and glycine

Water‐soluble, biodegradable, and biocompatible poly(ester‐amide) dendrimers with hydroxyl functional groups are synthesized from previously prepared AB₂ adduct of 2,2‐bis(hydroxymethyl) propanoic acid (bis‐MPA) and glycine as a repeating unit. Two esterification procedures using different coupling reagent/catalyst systems (DCC/DPTS or EDC/DMAP) are studied with respect to efficiency, ease of products purification, and quality of the final products. Both procedures have their own benefits and drawbacks, depending on dendrimer generation. The synthesized poly(ester‐amide) dendrimers as well as commercially available bis‐MPA dendrimers, poly(ester‐amide) hyperbranched polymer, and poly(vinyl alcohol) are used for preparation of solid dispersions of sulfonylurea antidiabetic drug glimepiride to improve its poor water‐solubility. In vitro dissolution studies show in comparison with pure glimepiride in crystalline or amorphous form, to the same extent improved glimepiride solubility for solid dispersions based on dendritic polymers, but not for poly(vinyl alcohol). The amount of glimepiride complexed with both dendrimer types increases with dendrimer generation. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3292–3301     

pH‐responsive photoluminescence properties of a water‐soluble copolymer containing quinoline groups in aqueous solution

The synthesis of a water‐soluble copolymer containing quinoline groups, P(DMAM‐co‐SDPQ), through free radical copolymerization of N,N‐dimethylacrylamide, DMAM, with 2,4‐diphenyl‐6‐(4‐vinylphenyl)quinoline, SDPQ, is presented and the optical properties of the final product are investigated in aqueous solution as a function of pH. It is found that the emission peak of SDPQ is red‐shifted from 411 to 484 nm with decreasing pH, due to the protonation of quinoline groups at low pH, suggesting that this copolymer may function as a luminescent pH‐indicator. Moreover, the copolymer exhibits the characteristics of a luminescent pH‐detector within the pH range 2 < pH < 4, as in this pH region the ratio of the emission intensity at 411 nm over that at 484 nm changes linearly in a logarithmic scale with the pH of the solution. Finally, the formation of less polar quinoline clusters in the aqueous P(DMAM‐co‐SDPQ) solution upon increasing pH was detected through Nile red probing. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2078–2083, 2010