The interaction between rhodamine 6G and different polyelectrolytes is analyzed. Structural aspects differentiate these polyelectrolytes, such as the presence of aromatic groups and the number and localization of their respective charges, which may be directly attached to the aromatic groups or to the polymeric main chain. In the case of poly(sodium acrylate), which does not bear aromatic groups, the polyelectrolyte induces cooperative self-stacking between the dyes which is highly sensitive to the ionic strength, due to the predominance of long-range electrostatic interactions between the polymer and the dye. In the case of poly(sodium 4-styrenesulfonate), whose charge is directly attached to the aromatic groups, a high dispersant ability of the dyes is found and the interaction is less dependent on the ionic strength, due to the predominance of short-range aromatic-aromatic interactions between the dye and the polymer. Among the two polyelectrolytes studied for which the polymeric charge is directly attached to the main chain, and separated from the aromatic group, poly(styrene-alt-maleic acid) shows a lower dependence of the interaction on the ionic strength than poly(N-phenylmaleimide-co-acrylic acid) at a comonomer composition of 1:2, due to a higher linear aromatic density and a lower linear charge density, indicating the importance of hydrophobic forces. Both copolymers exhibit a high ability to induce cooperative self-aggregation of the dye.

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 polymermetal complexes of divalent transition-metal ions were characterized by elemental analysis, Fourier transform infrared, 1 H 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 8C, and it decreased when the complexes of Co(II) and Cu(II) at pHs 3-7 were formed. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: [4933][4934][4935][4936][4937][4938][4939][4940][4941] 2005

Water‐soluble poly[(N‐maleoylglycine)‐co‐(hydroxyethyl methacrylate)] was employed for the separation of a series of metal ions in the aqueous phase using the liquid‐phase polymer‐based retention method. The method is based on the retention of inorganic ions by this polymer in conjunction with membrane filtration and subsequent separation of low‐molecular‐mass species from the polymer complex formed. It is shown that the polymer can bind several metal ions in aqueous solution at pH 3, 5, and 7, for example Cr(II), Co(II), Zn(II), Ni(II), Cu(II), Cd(II), Pb(II) inorganic ions. The interaction of the inorganic ions with the hydrophilic polymer was determined as a function of pH and filtration factor. The water‐soluble polymeric reagent with strong metal‐complexing properties was synthesized and used to separate complexed from non‐complexed ions in the homogeneous phase. The polymer exhibited high retention capability at pH 5 and 7. It was characterized by elemental analysis, FT‐IR, 1H NMR, and 13C NMR spectroscopy, as well as by thermogravimetry. Additionally, viscosimetric measurements of the copolymer were performed at different pH values. magnified image

This study investigates the use of homogeneous reverse atom transfer radical polymerization for the synthesis of polystyrene (PS) initiated by conventional radical peroxide with copper bromide in the lower oxidation state and a 2,2′‐bypyridine complex as the catalyst. In a second stage, an amphiphilic block copolymer containing methyl methacrylate (MMA) was synthesized via normal atom transfer radical polymerization in two steps, followed by partial hydrolysis of the methyl ester linkage of the MMA block under acidic conditions. The block copolymer PS699‐b‐P(MMA232/MAA58) obtained had a narrow molecular weight dispersity (Ð < 1.3). The structure of the precursor, PS‐b‐PMMA, and resultant polymer, was characterized and verified by FTIR and 1H‐NMR spectroscopy as well as size exclusion chromatography. The self‐aggregation of PS699‐b‐P(MMA232/MAA58) in organic solvents was monitored by UV spectroscopy, whereas the morphology and size of the formed microaggregates were investigated by transmission electron microscopy and dynamic light scattering. The results indicate that this copolymer formed regular spherical reverse micelles with a core–shell structure. The atomic force micrographs of PS699‐b‐P(MMA232/MAA58) showed a rough surface morphology owing to microphase separation of the block copolymer. In addition, thermal characterization was performed by differential scanning calorimetry and thermogravimetric analysis. The glass transition temperature of PS699‐b‐P(MMA232/MAA58) decreased significantly (65°C), when compared to PS and PMMA, suggesting that an enhanced movement of the polymer chains resulted by the segregation of the hydrolyzed P(MMA232/MAA58) block. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013