New polymeric structures designed for the removal of Cu(II) ions from aqueous solutions

New polymeric structures obtained by chemical transformations of maleic anhydride/dicyclopentadiene copolymer with triethylenetetraamine, p‐aminobenzoic acid, and p‐aminophenylacetic acid were used for the removal Cu(II) ions from aqueous solutions. The experimental values prove the importance of the chelator nature and of the macromolecular chain geometry for the retention efficiency. The retention efficiency (η_r), the retention capacity (Q _e ), and the distribution coefficient of the metal ion into the polymer matrix (K _d ) are realized by evaluation of residual Cu(II) ions in the effluent waters, by atomic adsorption. Also are discussed the influence of pH, the thermal stability of the polymer, and their polymer–metal complex, as well as the particular aspects regarding the contact procedure and the batch time. Based on the polymers and polymer–metal complexes characterization a potential retention mechanism is proposed. All polymer supports as well theirs metal–complexes are characterized by ATD and FTIR measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1397–1405, 2007     

Supramolecular assembled C60-containing carboxylated poly(dimethylsiloxane) composites

Supramolecular assembled nanocomposites were prepared through the solution casting of the complexing mixtures from the side chain carboxylated poly(dimethylsiloxane) (PDMS) with the 1-(4-methyl)-piperazinylfullerene (MPF). FT-IR and XPS analyses reveal that there are strong ionic interactions between the two components. Small-angle X-ray scattering study shows the formation of MPF fullerene nanodomains dispersed in the PDMS matrix, but no highly ordered structures, which is confirmed with TEM images. Compared to its polymeric precursor, the MPF crosslinked composites exhibit superior thermal mechanical stability and dramatic increase in the storage and loss moduli. Moreover, elastic response exceeds viscous response in the composites due to the formation of crosslinking structures. The increase of the MPF content in the composites leads to a denser packing of MPF nanodomains, resulting in better thermal, mechanical, and viscoelastic properties. The decrease in the carboxylic acid groups along the PDMS chains reduces the crosslinking density of the PDMS/MPF composites. The composites show a combined dielectric property from both PDMS and MPF components.     

Electrochemical behavior of a new type of perfluorinated carboxylate membrane/platinum composite

A new type of ionomeric polymer–metal composite (IPMC) based on various compositions of perfluoroalkylacrylate‐acryl acid copolymer with different types of counter cation has been synthesized by a radical copolymerization of fluoroalkylacrylate (FA) and acrylic acid (AA). Swelling behavior of the membranes was studied in deionized water as well as in aqueous single salt solutions (LiCl and NaCl). Swell of membrane increased with the increase in ionic content of the copolymer. Swell in deionized water was much higher than in aqueous single salt solution. To examine its performance as a new electroactive polymer, actuation force and displacement responses to DC and step voltage across the IPMC were measured. Results indicated that membranes prepared from 75/25 (FA/AA) (FA25) gave an adequate flexibility and proper hydrated state, allowing easy deflection toward the applied voltage. Surface morphology measurements (atomic force microscopy and scanning electron microscopy) showed that platinum particles are predominantly located at the surfaces. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Automated protein-ligand crystallography for structure-based drug design

An approach to automate protein-ligand crystallography is presented, with the aim of increasing the number of structures available to structure-based drug design. The methods we propose deal with the automatic interpretation of diffraction data for targets with known protein structures, and provide easy access to the results. Central to the system is a novel procedure that fully automates the placement of ligands into electron density maps. Automation provides an objective way to structure solution, whereas manual placement can be rather subjective, especially for data of low to medium resolution. Ligands are placed by docking into electron density, whilst taking care of protein-ligand interactions. The ligand fitting procedure has been validated on both public domain and in-house examples. Some of the latter deal with cocktails of low-molecular weight compounds, as used in fragment-based drug discovery by crystallography. For such library-screening experiments we show that the method can automatically identify which of the compounds from a cocktail is bound.     

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     

Polyelectrolyte complex membranes based on two anionic polysaccharides composed of sodium alginate and carrageenan: The effect of annealing on the separation of methanol/water mixtures

Through the complexation of two anionic polysaccharide blends composed of sodium alginate and carrageenan with divalent calcium ions, polyelectrolyte complex membranes were prepared. The effects of annealing on the structure of the polyelectrolyte complex membranes and on their performance at removing water from a methanol mixture were investigated and discussed. The annealed membranes exhibited a change in their crystallinity. The change was due to a rearrangement of polymer chains, which was induced by a deformation of the chelate structure and intramolecular or intermolecular interactions between the polysaccharides. Because of the effects of annealing on the resulting membranes, water components almost penetrated the membranes to the permeate side in the vapor permeation process. Moreover, the membrane performances were gradually enhanced as the operating temperature increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5781–5788, 2006     

Thermal behavior of poly(acrylic acid)–poly(vinyl pyrrolidone) and poly(acrylic acid)–metal–poly(vinyl pyrrolidone) complexes

Thermal analysis (TGA and DTA) of samples of PAA, PVP, PAA–PVP complexes, containing different weight fractions of PAA and ternary polymer–metal–polymer complexes, were studied. The activation energy parameters for the thermal degradation were also calculated. The study of the effect of FeCl₃, NiCl₂, and Ni(NO₃)₂ on the TGA and DTA curves of the complexes showed that the decompositions are dependent on the concentrations and the nature of the metal ions. The DTA traces of PAA–PVP complex containing FeCl₃, NiCl₂, and Ni(NO₃)₂ showed that the treatment of the complex with these metal ions causes considerable changes in the thermal decomposition of PAA–PVP complex. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4049–4057, 2006     

微胶囊技术应用于纺织染整研究进展

概述印染行业对水资源的污染和染色工作者围绕清洁生产所做的努力。介绍了目前国内外在微胶囊染料的研究动态、性能特点和使用效果,同时也展现了我们在瓜环与酸性金黄G相互作用的初步研究。     

二茂铁衍生物环钯化合物的研究进展

通过与二茂铁环连接方式的多样性,已成功地合成了大量的二茂铁环钯化合物,此类化合物广泛地应用化学、生物、医药等领域.本文综述了二茂铁环钯化合物的研究进展.     

Studies on the formation of 5-aminosalicylate intercalated Zn-Al layered double hydroxides as a function of Zn/Al molar ratios and synthesis routes

The 5-aminosalicylate intercalated Zn-Al layered double hydroxides (LDHs) with variable Zn/Al molar ratios have been synthesized by both direct coprecipitation (CP) and indirect ion exchange (EX) methods. As-synthesized solids have been characterized by powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-visible spectroscopy (UV-Vis), thermal gravimetric analysis (TG) and inductively coupled plasma (ICP) emission spectroscopy, and CHN elemental microanalysis. The results indicate that the supramolecular structure and the loading percentage are highly dependent on the layer charge density and the synthesis routes of the LDHs materials. Four schematic supramolecular structural models of the 5-aminosalicylate intercalates have been proposed, including the staggered dentate-like monolayer arrangement, the vertically adjacent monolayer arrangement, the vertically distant bilayer arrangement, and the vertically adjacent bilayer arrangement. The EX products present highly ordered crystallite than CP ones and the intercalates with higher layer charge density, i.e., the lower Zn/Al ratio, exhibit more ordered crystal structure and higher thermal stability than those with lower layer charge densities.