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Polymeric Surfactants (polymeric + surfactant)

Distribution by Scientific Domains

Polymers and Materials Science	40%
Chemistry	20%

Selected Abstracts

Tellurium-Based Polymeric Surfactants as a Novel Seleno-Enzyme Model with High Activity

MACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2006
Xin Huang
Abstract Summary: A tellurium-based polymeric sufactant as a seleno-enzyme model has been constructed by employing 11-acryloyloxyundecyltriethylammonium bromide (AUTEAB, 4) and a tellurium-containing compound (1). It demonstrates strong substrate binding ability for thiols and high glutathione peroxidase (GPx) activity about 6 orders of magnitude more efficient than the well-known GPx mimic PhSeSePh in an ArSH assay system. More importantly, a series of tellurium-based polymeric micelle catalysts with the catalytic tellurium center located at various positions in the micelle have been constructed, and the dramatic difference in activity indicates that the exact match of the catalytic center and binding site plays a key role in enzyme catalytic efficiency. Schematic representation of the proposed mode of the telluro-micelle catalysts. [source]

Application of polymeric surfactants in micellar electrokinetic chromatography-electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

ELECTROPHORESIS, Issue 5-6 2006
Jingguo Hou
Abstract Chiral micellar EKC (CMEKC) coupled to ESI-MS using polymeric surfactants as pseudostationary phases is investigated for simultaneous enantioseparation of two benzodiazepines, (±)-oxazepam ((±)-OXA) and (±)-lorazepam ((±)-LOR), and one benzoxazocine, (±)-nefopam ((±)-NEF). First, enantioselectivity and electrospray sensitivity of six chiral polymeric surfactants for all three chiral compounds are compared. Second, using poly(sodium N -undecenoyl- L -leucinate) as pseudostationary phase, the organic modifiers (methanol (MeOH), isopropanol, and ACN) are added into the running buffer to further improve chiral resolution (RS). Next, a CMEKC-ESI-MS method for the simultaneous enantioseparation of two benzodiazepines is further developed by using a dipeptide polymeric surfactant, poly(sodium N -undecenoxy carbonyl- L,L -leucyl-valinate) (poly- L,L -SUCLV). The CMEKC conditions including nebulizer pressure, capillary length, ammonium acetate concentration, pH, poly- L,L -SUCLV concentration, and capillary temperature were optimized to achieve maximum chiral RS and highest sensitivity of MS detection. The spray chamber parameters (drying gas temperature and drying gas flow rate) as well as sheath liquid conditions (MeOH content, pH, flow rate, and ionic strength) were found to significantly influence MS S/N of both (±)-OXA and (±)-LOR. Finally, a comparative study between simultaneous UV and MS detection showed high plate numbers, better chiral RS, and enhanced detectability with CMEKC-MS. However, speed of analysis was faster using CMEKC-UV. [source]

Emulsion polymerization of styrene with amphiphilic random copolymer as surfactant: Predominant droplet nucleation

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009
Li Liu
Abstract Amphiphilic random copolymer consisting of monomeric units of poly (butyl acrylate) and poly (maleic acid salt) was synthesized and characterized. The emulsion polymerization kinetics of styrene stabilized by this copolymer was investigated. The influencing factors, including polymeric surfactant concentration, initiator concentration and polymerization temperature, were systematically studied. The kinetic data show that the polymerization rate (RP) increased with the increase of the polymeric surfactant concentration ([S]) and polymerization temperature (T). At the higher [S], droplets nucleation and micelle nucleation coexisted in the polymerization system; at the lower [S], only the droplets nucleation process existed. The polymerization did not follow Smith-Ewart Case II kinetics. Dynamic light scatter and transmission electron microscope were utilized to measure the sizes and shapes of the particles, respectively. It would be speculated that a kind of large heterogeneous particles with multiple-active-sites was formed in the polymerization system. The increasing of RP with increasing initiator concentration ([KPS]) was rapid at a medium [KPS], but the slowly increasing was observed at a lower or higher [KPS]. It was attributed to the barrier effect of the polymeric surfactant around the monomer droplets. The polymerization activation energy was 60.29 kJ/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]

Emulsion synthesis of nanoparticles containing PEDOT using conducting polymeric surfactant: Synergy for colloid stability and intercalation doping

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2008
Chi-an Dai
Abstract Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is a widely used conductive aqueous dispersion synthesized by using emulsion polymerization method. To further enhance its solution processability and conductivity of PEDOT derivatives, we proposed to replace the nonconductive PSS with conductive poly[2-(3thienyl)-ethoxy-4-butylsulfonate] (PTEB) as surfactant for the emulsion polymerization of PEDOT. The reaction involved colloid stabilization and doping in one step, and yielded PEDOT:PTEB composite nanoparticles with high electrical conductivity. Contrary to its counterpart containing nonconductive surfactant, PEDOT: PTEB showed increasing film conductivity with increasing PTEB concentration. The result demonstrates the formation of efficient electrical conduction network formed by the fully conductive latex nanoparticles. The addition of PTEB for EDOT polymerization significantly reduced the size of composite particles, formed stable spherical particles, enhanced thermal stability, crystallinity, and conductivity of PEDOT:PTEB composite. Evidence from UV,VIS and FTIR measurement showed that strong molecular interaction between PTEB and PEDOT resulted in the doping of PEDOT chains. X-ray analysis further demonstrated that PTEB chains were intercalated in the layered crystal structure of PEDOT. The emulsion polymerization of EDOT using conducting surfactant, PTEB demonstrated the synergistic effect of PTEB on colloid stability and intercalation doping of PEDOT during polymerization resulting in significant conductivity improvement of PEDOT composite nanoparticles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2536,2548, 2008 [source]

Application of polymeric surfactants in micellar electrokinetic chromatography-electrospray ionization mass spectrometry of benzodiazepines and benzoxazocine chiral drugs

Enantioselectivity of alcohol-modified polymeric surfactants in micellar electrokinetic chromatography

ELECTROPHORESIS, Issue 15 2003
Jepkoech Tarus
Abstract A novel method of modifying sodium undecanoyl- L -leucinate (SUL) micelles employed in chiral separation of analytes in micellar electrokinetic chromatography (MEKC) to enhance selectivity toward specific analytes is discussed. The current study aimed at modifying the SUL micelles by introducing different alcohols into the mono-SUL micelles. The micellar solutions were then polymerized in the presence of alcohols followed by postpolymerization extraction of the alcohols to yield alcohol-free polymeric surfactants (poly- L -SUL). The effects of hexanol (C6OH) and undecylenyl alcohol (C11OH) on micellar properties of this surfactant were investigated by use of surface tensiometry, fluorescence spectroscopy, pulsed field gradient-nuclear magnetic resonance (PFG-NMR), and MEKC. The surface tension and PFG-NMR studies indicated an increase in the critical micelle concentration (cmc) and micellar size upon increasing the alcohol concentration. Fluorescence measurements suggested that alcohols induce closely packed micellar structures. Coumarinic and benzoin derivatives, as well as (±)-1, 1'-binaphthyl-2,2'-dihydrogen phosphate (BNP) were used as test analytes for MEKC experiments. Examination of MEKC data showed remarkable resolutions and capacity factors of coumarinic derivatives obtained with modified poly- L -SUL as compared to the unmodified poly- L -SUL. Evaluation of fluorescence, PFG-NMR, and MEKC data suggest a strong correlation between the polarity and hydrodynamic radii of alcohol-modified micelles and the resolution of the test analytes. [source]

Effectiveness test of alginate-derived polymeric surfactants

JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2002
Hyun-Ah Kang
Abstract A series of alginate-derived polymeric surfactants (APSs) with a linear alkyl group (C8, C12, C16) was synthesized by oxidation followed by reductive amination of 2,3-dialdehydic alginate. The products were characterized by measuring IR spectra, NMR spectra, surface tension and critical micelle concentration (cmc). They were also tested for the solubilization of azobenzene and adsorption of heavy metal. In the case of 40% CHO-C8 APSs, the lowest interfacial tension value (31.5,m Nm,1) was obtained at the cmc value of 1.35,g,dm,3. The dissolving capacity of 40% CHO-C8 APS towards azobenzene was 27 times greater than that of alginate. The overall cobalt (Co2+) removal efficiency by adsorption using APSs was high compared with that of sodium alginate at pH 3, 5 and 7. Equilibrium aspects of cobalt adsorption onto 10% CHO-APSs were studied, and the results show that APSs had high equilibrium capacities for cobalt uptake, 115.5,mgg,1. © 2002 Society of Chemical Industry [source]

Intracellular uptake and trafficking of Pluronic micelles in drug-sensitive and MDR cells: Effect on the intracellular drug localization

JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 1 2002
Natalya Rapoport
Abstract The intracellular uptake and localization of a fluorescently labeled Pluronic P-105 in HL-60 leukemia cells and in A2780 drug-sensitive and A2780/ADR MDR ovarian carcinoma cells were characterized by flow cytometry and fluorescence microscopy. Pluronic P-105 molecules were labeled with a pH-sensitive fluorescent label, 5-(and 6-)carboxy-2,7,-dichlorofluorescein. The fluorescence intensity of labeled Pluronic was about twofold higher at pH 7.4 than at pH 5.5. At Pluronic concentrations exceeding the critical micelle concentration (cmc), flow cytometry histograms manifested bimodal distribution of cell fluorescence for all types of cells. Cell population characterized by higher fluorescence intensity presumably resulted from Pluronic transfer from the acidic environment of cytoplasmic vesicles (endosomes or lysosomes) into the neutral environment of the cytoplasm and cell nuclei, which suggested the permeabilization of the membranes of acidic vesicle by Pluronic molecules. For the MDR cells, the bimodal distribution of cell fluorescence was already observed at very low Pluronic concentrations in the incubation medium (i.e., below the cmc). The data suggest that the membranes of acidic vesicles of MDR cells are more susceptible to the action of polymeric surfactants than those of drug-sensitive cells. Permeabilization of acidic vesicles had a dramatic effect on the intracellular trafficking of drugs: when delivered in PBS, the anthracyclin drug ruboxyl (Rb) sequestered in cytoplasmic vesicles and was excluded from cell nuclei; however, when delivered in Pluronic micelles, drug accumulated in cell nuclei. Drug uptake from/with Pluronic micelles was substantially enhanced by ultrasound. These findings suggest that the nuclear accumulation of drugs internalized via fluid-phase endocytosis can be enhanced by the application of Pluronic micelles and can be further augmented by ultrasonic irradiation. © 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:157,170, 2002 [source]

Synthesis of poly(vinyl ether) polyols with pendant oxyethylene chains and properties of hydrophilic, thermo-responsive polyurethanes prepared therefrom

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 7 2010
Tamotsu Hashimoto
Abstract Hydroxy-terminated telechelic poly(vinyl ether)s with pendant oxyethylene chains were synthesized by the reaction of the CH3CH(OCOCH3)O[CH2]4OCH(OCOCH3)CH3/Et1.5AlCl1.5/THF-based bifunctional living cationic polymers of 2-methoxyethyl vinyl ether (MOVE), 2-ethoxyethyl vinyl ether (EOVE), and 2-(2-methoxyethoxy)ethyl vinyl ether (MOEOVE) with water and the subsequent reduction of the aldehyde polymer terminals with NaBH4. The obtained poly(vinyl ether) polyols were reacted with an equimolar amount of toluene diisocyanates [a mixture of 2,4- (80%) and 2,6- (20%) isomers] to give water-soluble polyurethanes. The aqueous solutions of these polyurethanes caused thermally induced precipitation at a particular temperature depending on the sort of the thermosensitive poly(vinyl ether) segments containing oxyethylene side chains. These polyurethanes also function as polymeric surfactants, lowered the surface tension of their aqueous solutions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1641,1648, 2010 [source]

Poly(vinyl chloride) on the way from the 19th century to the 21st century

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2004
D. Braun
Abstract Despite all the technical and economic problems and the public discussions on the environmental dangers and hazards of chlorine chemistry, poly(vinyl chloride) (PVC) is the second most produced plastic (with a worldwide capacity of about 31 million tons), placing after polyolefins and before styrene polymers. Presently, PVC production worldwide is growing at a rate of more than 4% per year. The application of PVC was first described in a patent in 1913, but only after 1930 did a sustained interest in PVC arise in several industrial laboratories. The most remarkable milestones in PVC history and their importance to the development of macromolecular chemistry are briefly described, and some present PVC research and industrial applications, with respect to polymerization, stabilization, bulk property modification, and chemical and material recycling of PVC waste, are discussed. Some actual selected topics include the emulsion polymerization of vinyl chloride with polymeric surfactants and controlled free-radical polymerization with nitroxyls, whereas ionic and metal organic initiators have not found any technical applications. Chemical reactions offer many possibilities for the modification of PVC, but they have been not used on a technical scale yet. Much work has been done on stabilization with nontoxic or metal-free systems. The bulk properties of PVC can be influenced by impact modification through the addition of graft copolymers or by blending with other polymers. Also presented are some problems and recent developments in PVC recycling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 578,586, 2004 [source]

Surface activity,thermodynamic properties and light scattering studies for some novel aliphatic polyester surfactants

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 5 2004
R. A. El-Ghazawy
Abstract The preparation of 12 new polyester surfactants based on aliphatic amines and different ethylene oxide content is described. These surfactants were characterized by determining their molecular weights and polydispersity by gel permeation chromatography (GPC) and nitrogen content. Drop volume tensiometry (DVT) was used to measure the surface tension at 25, 35, 45 and 55°C. The surface tension isotherms were used to determine critical micelle concentration (CMC), maximum Gibb's adsorption (,max), minimum area per molecule (Amin), the effectiveness of surface tension reduction (,cmc) and the efficiency (pC20). The thermodynamic parameters of micellization (,Gmic, ,Hmic, ,Smic) and of adsorption (,Gad, ,Had, ,Sad) were calculated and the data showed that these surfactants favor micellization to adsorption. The static scattered light intensity measurements provide the calculation of the molecular weight of micelle and the aggregation number (N°), while the dynamic light scattering provide the hydrodynamic radius of micelle (RH) and the diffusion coefficient at different surfactant concentrations. The hydrodynamic radius of micelle (RH) at different surfactant concentrations could be used also to determine the CMC giving results that are comparable to those obtained by surface tension measurements. All the data are discussed regarding the chemical structure of the polymeric surfactants. Copyright © 2004 John Wiley & Sons, Ltd. [source]