Presence Of Water-soluble Polymers Research Articles

Unlike surfactant?polymer interactions of sodium dodecyl sulfate and sodium dodecylbenzene sulfonate with water-soluble polymers

Single and mixed micelle formation by sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) and their mixtures in pure water and in the presence of water-soluble polymers such as Synperonic 85 (triblock polymer, TBP), hydroxypropylcellulose (HPC), and carboxymethylcellulose sodium salt (CMC) were studied with the help of conductivity, pyrene fluorescence, cyclic voltammetry, and viscosity measurements. Conductivity measurements showed a single aggregation process for pure surfactants and their mixtures both in pure water as well as in the presence of water-soluble polymers. Triple breaks corresponding to two aggregation processes for SDS, SDBS, and their mixture in the presence of TBP were observed from fluorescence measurements. The first one demonstrated the critical aggregation process due to the adsorption of surfactant monomers on TBP macromolecule. The second one was attributed to the participation of surfactant–polymer aggregates formed at the first one, in the micelle formation process. The aggregation number (N agg ) of single and mixed micelles and diffusion coefficient (D) of electroactive probe were computed from the fluorescence and cyclic voltammetry measurements, respectively. Both parameters, along with the viscosity results, indicated stronger SDS–polymer interactions in comparison to SDBS–polymer interactions. Mixed surfactant–polymer interactions showed compensating effects of both pure surfactants. The nature of mixed micelles was found to be ideal in all cases, as evaluated by applying the regular solution and Motomura's approximations.

Water-soluble polymers for spectrophotometric and flow injection determination of cobalt with nitroso-R-salt

The water-soluble polymers poly(ethylenimine), quaternized poly(ethylenimine), and poly-4-vinyl-( N-benzyltrimethyl) ammonium chloride were found to be able to change the kinetics of the reaction of cobalt with nitroso-R-salt and the optical density of the cobalt complex formed. The optimum pH range for the complex formation was a wide range from 1 to 10 and at pH 2 the reaction developed instantly. The calibration graph was linear in the range 0.005–2 μg ml −1. The effective molar absorptivity coefficient of the complex was equal to (2.8±0.08)10 3. A spectrophotometric determination method for cobalt with nitroso-R-salt in the presence of water-soluble polymers (before and after membrane preconcentration) and a colorimetric flow injection method were developed. For the flow injection-based spectrophotometric determination, the calibration graph was linear in the concentration range of 0–4.0 μg ml −1 cobalt with a regression coefficient of 0.9992. The relative standard deviation (R.S.D.) for the determination of 1.0 μg ml −1 cobalt was 0.9% (ten replicate injections), and at all concentration measured, the R.S.D. of the data was below 5.0%. The proposed FI procedure was applied to river water samples after membrane preconcentration of cobalt. The limit of detection was 4 ng ml −1.

Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder. Part II: Thermal, FTIR and morphological characterisation

Radiation induced grafted polyacrylic acid (PAA), polymethacrylic acid (PMAA), polyacrylamide (PAAm), poly N,N-dimethyl acrylamide (PNDAAm) and poly 1-vinyl-2 pyrrolidone (PVP) on ultra-high molecular weight polyethylene (UHMWPE) were characterised by DSC, FTIR and SEM analysis. While the effect of irradiation on pure UHMWPE was found to increase crystallinity and cause higher enthalpy of crystallisation, grafted UHMWPE powders showed lower crystallinity and enthalpy of crystallisation. In all grafted UHMWPE there existed secondary transitions corresponding to grafting polymers in the first run of DSC above 60°C and they became clearer at a higher grafting level. In the second run of DSC some Tg values appeared to shift to higher temperatures while some were not detected. FTIR analysis indicated the presence of water-soluble polymers in the grafted UHMWPE. The characteristic peaks of water-soluble polymers became sharper in the grafted UHMWPE. SEM analysis revealed that the grafting occurs both on fiber and microparticles of UHMWPE while flowing characteristic of powder is retained.

Evaluation of biocompatibility of the surface of polyethylene films modified with various water soluble polymers using Ar plasma-post polymerization technique

Surface modified polyethylene (g-PE), PMPC-g-PE, PGEMA-g-PE, PNIPAAm-g-PE and PHPMA-g-PE films with the water soluble polymers such as poly[2-(methacryloyloxy)ethyl phosphorylcholine] (PMPC), poly[2-(glucosyloxy)ethyl methacrylate] (PGEMA), poly(N-isopropylacrylamide) (PNIPAAm) and poly[N-(2-hydroxypropyl) methacrylamide] (PHPMA) were prepared by graft copolymerization using an Ar plasma-post polymerization technique. The surface of the g-PE films was characterized by means of X-ray photoelectron spectroscopy and the grafting percentage of PMPC, PNIPAAm and PHPMA was found to be 5.31, 2.83, and 3.40% for the corresponding g-PE film. Biocompatibility of the g-PE films was evaluated by the adsorption of serum proteins and the Michaelis constant (K m ) for the enzymatic reaction of thrombin with synthetic substrate S-2238 in the presence of g-PE film. The biocompatibility of water soluble polymers such as PMPC, polyoxyethylene (POE), PGEMA, PNIPAAm and PHPMA was also evaluated by the same enzymatic reaction of thrombin with S-2238 in their polymer solutions. The K m values in the presence of water soluble polymers was found to decrease in the order PMPC > POE > PGEMA > PNIPAAm > PHPMA. As a conclusion, PMPC-g-PE film exhibited the most biocompatibility among g-PE films because its surface adsorbed less protein than those of the untreated PE and other g-PE films and it showed the largest K m for the enzymatic reaction.

Functional metallomacrocycles and their polymers, Part 37.: Oxidative decomposition of 2,4,6-trichlorophenol by polymer-bound phthalocyanines

Oxidative decomposition of 2,4,6-trichlorophenol (TCP) catalyzed by iron, manganese, and cobalt octacarboxyphthalocyanines and their polymer-bound derivatives was studied in aqueous solution. Iron octacarboxyphthalocyanine scarcely had catalytic activity in oxidative decomposition of TCP by H 2O 2, while extremely high catalytic activity was observed in the presence of water-soluble polymers having pyridinium side chains. When iron octacarboxyphthalocyanine complex was covalently bound to the water-soluble cationic polymer, it revealed much higher catalytic activity. 2,6-Dichloro- p-benzoquinone was formed in the initial period of the reaction and was decomposed to further low molecular weight compound. Formic acid, oxalic acid, chloropropenic acid, and two coupling products were found in the resulting solution by GC–MS analysis. Catalytic activity of polymer-bound iron phthalocyanine was strongly influenced by pH and the maximum activity was observed at pH 7. The pH-dependence of the catalytic activity was explained by the dissociation of TCP. Enhancement in catalytic activity by polymer chain was also observed in manganese and cobalt phthalocyanine complexes. Highly efficient dechlorination of TCP was concomitantly achieved by the polymer-bound iron and manganese phthalocyanine complexes, while polymer-bound cobalt phthalocyanine complex hardly cause the dechlorination.

A New Monolithic-Type HPLC Column For Fast Separations

Summary The application of a new silica-based, monolithic-type HPLC-column for fast separations is presented. The column is prepared according to a new sol-gel process, which is based on the hydrolysis and polycondensation of alkoxysilanes in the presence of water soluble polymers. The method leads to “rods” made of a single piece of porous silica with a defined pore structure, i. e. macro- and mesopores. The main feature of silica rod columns is a higher total porosity, about 15% higher than of conventional particulate HPLC columns. The resulting column pressure drop is therefore much lower, allowing operation at higher flow rates including flow gradients. Consequently, HPLC analysis can be performed much faster, as it is demonstrated by various applications.

Determination of Ag(I), Hg(II), Cu(II), Pb(II), Cd(II) by stripping voltammetry in aqueous solutions using complexing polymers in conjunction with membrane filtration

The electrochemical behavior of a series of metal ions (Ag(I), Hg(II), Cu(II), Pb(II), Cd(II)) and the ternary Cu(II)–Pb(II)–Cd(II) system in the solutions of water-soluble complexing polymers poly(ethylenimine) (PEI), poly(1-vinyl-2-pyrrolidone) (PVP), their thiourea-containing derivatives poly(ethyleneimine)methylthiourea (PEI-TU) and poly(1-vinil-2-pyrrolidone)methylthiourea (PVP-TU) was investigated using cyclic and anodic stripping voltammetry (ASV) at different carbon electrodes. The optimum conditions were selected for the stripping voltammetric determination of Ag(I), Hg(II), Cu(II), Pb(II) and Cd(II) in a concentration range from 10 −6 to 10 −5 M in the presence of water-soluble polymers at the carbon-paste electrode (the relative standard deviation did not exceed 10%). The stability of metal complexes with PEI was established to decrease in the following order: Hg(II) > Cu(II) > Ag(I) > Cd(II) > Pb(II). The hydrophilic polymer PEI is shown to reduce the intermetallic interactions of components of the Cu(II)–Pb(II)–Cd(II) ternary system on the electrode surface. The different complex stabilities of Pb(II), Cd(II) and Cu(II) with PEI allow to determine Pb(II) and Cd(II) in the presence of a larger excesses of Cu(II) (100/1 and 10/1, respectively) compared to a procedure without PEI (10/1 and 0.33/1, respectively). The conditions were optimized for the simultaneous stripping voltammetric determination of the components of the divalent Pb(II)–Cu(II)–Cd(II) system in 2% aqueous solutions of PEI. Finally, the possibility of determining Cu(II) and Pb(II) in tap water after preconcentration as PEI complexes using membrane filtration was demonstrated.

On the prediction of evaporation rates—With special emphasis on aqueous solutions

The performance of a theoretically based model for the prediction of evaporation rates of liquid mixtures is investigated with special emphasis on aqueous solutions. The model is an extension of a previously suggested evaporation model for pure volatile organic compounds. Liquid phase nonideality is corrected for by use of activity coefficients. A comparison with experimental data on evaporation of various liquid mixtures shows that the inclusion of activity coefficients is often mandatory for occupational hygiene applications. The potential risk of exposure associated with hydrophobic compounds in minute concentrations in water is demonstrated. Activity coefficients for a wide range of mixtures can be estimated accurately using the group-contribution method UNIFAC. For certain strongly non-ideal aqueous mixtures UNIFAC is less accurate and experimental infinite dilution activity coefficients should be applied if available. For liquid mixtures, measured and predicted evaporation rates were in satisfactory agreement, indicating that liquid phase diffusional resistance can be neglected also in strongly non-ideal aqueous solutions. It was found, however, that the presence of water-soluble polymers in aqueous solutions suppresses the evaporation of volatile organic compounds, even at low concentrations, owing to liquid phase diffusional resistance and reduced activity. Liquid phase diffusional resistance due to polymers was found to increase with liquid viscosity and volatility of the dilute organic compound. This effect cannot be predicted by the evaporation model.

ミセルを反応場とする自発重合

Spontaneous polymerization is defined as the thermally initiated polymerization of pure monomers without initiators being added in the dark. The present review concerns with the spontaneous polymerizations of vinyl monomers in three kinds of anisotropic systems : a micellar solutions of some amphiphilic monomers capable of forming micelles, b emulsion of oil-soluble monomers such as styrene and methyl methacrylate with conventional surfactants, and c aqueous suspension of the oil-soluble monomers in the presence of water-soluble polymers (polysoaps). In a, as a feature of the polymerization systems, the monomer aggregation state has a very important role in controlling the generation of initiating radical species. In b and c, the monomers solubilized in the micelles formed by the surfactants or the polysoaps are assumed to be active for the radical formation. The generalized initiation mechanisms are discussed.

Synthesis of Zeolite Y in the Presence of Water-soluble Polymer (II)

Synthesis of Zeolite Y in the Presence of Water-soluble Polymer (II)

Storage stabilization and purification of enzyme by water-soluble synthetic polymers

Penicillin acylase purification and storage stabilization in the presence of water-soluble polymers were studied. Eleven synthetic polymers were evaluated in this survey. It was shown that protein suspension stabilization, precipitation, and enzyme denaturation were affected by both protein and polymer concentration and mostly depended on the particular polymer-enzyme system. The possibility of acylase purification was also described. Fivefold purification was reached if 30% sulfomethylated poly(acrylamide) in 0.1 wt. % concentration was used. Six of eleven polymers significantly increased enzyme stability for storage at 37°C, whereas three of them offered the purification effect. They were selected for future investigation.

Polymer- and micelle-protected gold/platinum bimetallic systems. Preparation, application to catalysis for visible-light-induced hydrogen evolution, and analysis of formation process with optical methods

The gold/platinum bimetallic systems stabilized by polymer and micelle were obtained by alcohol- and photo-reduction of the corresponding metal ions in the presence of water-soluble polymers and non-ionic surfactant-micelles, respectively. The UV-Vis spectra and the transmission electron micrographs suggest that the polymer-protected gold/platinum bimetallic systems are composed of bimetallic alloy clusters, but the micelle-protected ones are mostly composed of the mixtures of the monometallic gold and platinum clusters. The in-situ UV-Vis spectra during the reductions can elucidate the formation processes of the bimetallic dispersions which are different from each other depending on the protective reagent. The gold/platinum bimetallic systems can be used as the catalyst for visible light-induced hydrogen evolution. The bimetallic system stabilized by the polymer at a molar ratio of Au/Pt = 2 3 is the most active catalyst.

Crystallization of inorganic compounds in polymer solutions. Part I: Control of shape and form of calcium carbonate

Calcium carbonate was precipitated by mixing aqueous solutions of sodium carbonate and calcium nitrate in the presence of water-soluble polymers. When the former was poured into the latter, in which a certain amount of sodium poly(styrenesulfonate) was dissolved, monodisperse spherical crystals were created. The crystal form was vaterite, although, in the absence of the polymer, calcite crystals were obtained in rhombic shape. The factors deciding the shape and form of the crystal were investigated and the role of polymer in the formation of unique crystals was discussed.

Synthesis of nanocomposites: Organoceramics

We report here on the synthesis of new materials termed organoceramics in which polymers are molecularly dispersed within inorganic crystalline phases. These nanocomposite materials may not only have unique morphologies and physical properties but may also lead to new processing methods for ceramic-based materials. In organoceramics polymer molecules could opportunistically occupy sites such as grain boundaries or other two-dimensional defects, nanopores, lattice channels, or interlamellar spaces. Our synthetic approach to get macromolecules to those sites is to nucleate and grow inorganic crystals from homogeneous solutions containing the polymer chains as co-solutes. The new materials discussed in this manuscript were synthesized by growing calcium aluminate crystals in the presence of water soluble polymers and were characterized by x-ray diffraction, scanning electron microscopy, elemental analysis, and diffuse reflectance infrared spectroscopy. The macromolecules used in organoceramic synthesis included poly(vinyl alcohol), poly(dimethyldiallyl ammonium chloride), and poly(dibutyl ammonium iodide). We found that the chemistry of polymer repeats can impact on the spatial distribution of the dispersed organic chains and also on the morphology of organoceramic powders. In the case of the poly(vinyl alcohol) organoceramic the polymer is intercalated in “flattened” conformations in Ca2Al(OH)6[X] ·nH2O, thus increasing the distance between ionic layers from 7.9 Å to ∊ 18 Å (X is a monovalent or divalent anion). Such a layered nanocomposite can be formed only by intercalating the poly(vinyl alcohol) during growth of the Ca2Al(OH)6[X] · nH2O crystal. The synthetic pathway is therefore able to overcome large entropic barriers and incorporate significant amounts of polymer in the organoceramic product, in some cases up to 38% by weight. The particles of this nanocomposite are spheroidal aggregates of thin plate crystals whereas the use of a polycationic polymer in the synthesis leads to rod-like particles in which organic chains may reside in channels of the inorganic crystal.

Immunoassay in the presence of water-soluble polymers

To overcome the adverse consequences of antibody immobilization (impairment of the antigen-binding parameters) the interaction of a number of antigens with both soluble and covalently immobilized antibodies in the presence of water-soluble polymers has been investigated. Incorporation of some water-soluble polymers (Ficoll, Dextran) into the assay mixture was shown to substantially increase the antigen-binding capacity of both soluble and immobilized antibodies. The use of dextran T70 enhanced the sensitivity of competitive radioimmunoassays for CEA and β 2-microglobulin 3–4-fold. This procedure may be also applied to shorten the incubation period when performing an assay.

Modification of properties of ion exchange membranes. II. Transport properties of cation exchange membranes in the presence of water-soluble polymers

Electrodialytic transport properties of commercial cation exchange membranes in the presence of various water-soluble polymers were observed. The transport properties measured in this report were the relative transport number of calcium ion to sodium ion ( P Na Ca), the current efficiency of cations and the electric resistance of the membrane during the electrodialysis. Water-soluble polymers used were polyethyleneimine, poly- N,N-dimethylethyleneammonium sulfate, poly- N-vinylpyrrolidone and polyvinylalcohol. When electrodialysis was carried out using the cation exchange membrane in the presence of cationic polyelectrolytes, P Na Ca of most membranes decreased remarkably while the electric resistance of the membrane during the electrodialysis scarcely increased and the current efficiency increased or decreased slightly. For example, P Na Ca of the cation exchange membrane, Neosepta CL-25T, was 0.18 when the membrane had been exposed to the mixed salt solution containing 27.9 ppm of poly- N,N-dimethylethyleneammonium sulfate for 24 hr while P Na Ca of Neosepta CL-25T in the absence of it was 2.52. However, P Na Ca of the same membrane increased in the presence of poly- N-vinylpyrrolidone or polyvinylalcohol. In the case of polyethyleneimine, it was confirmed that monolayer type adsorption or ion exchange occurred on the surface of the membrane, about 90% of imino groups of polyethyleneimine which adsorbed on or ion exchanged with the membrane did not ion exchange with sulfonic acid groups of the membrane and P Na Ca decreased much more when pH of the mixed salt solution used in electrodialysis was low. Moreover, P Na Ca decreased remarkably in the presence of strongly basic polyelectrolyte more than weakly basic polyelectrolyte. The membrane property of monovalent cation permselectivity by adsorption of or ion exchange with polyelectrolyte was not easily lost. These membranes are preferentially permeable to sodium ion because the electrostatic repulsion force between calcium ion and the cationic surface charge of the membrane is larger than that between sodium ion and the cationic surface charge of the membrane. However, the increase of P Na Ca in the presence of poly- N-vinylpyrrolidone and polyvinylalcohol was not sufficiently explained in this report.