A Kinetic Study of the Emulsion Polymerization of Vinyl Acetate

DEFF Research Database (Denmark)

Friis, N.; Nyhagen, L.

1973-01-01

The emulsion polymerization of vinyl acetate was studied at 50°C. It was found that the rate of polymerization was proportional to the 0.5 power of the initiator concentration and the 0.25 power of the number of particles. The number of particles was proportional to the power 0.5 ± 0.......05 of the emulsifier concentration, but independent of the initiator concentration. The limiting viscosity number of the polymers produced was independent of the initiator concentration and number of polymer particles. It is suggested that the mechanism of vinyl acetate emulsion polymerization is similar...

Poly[diaquadi-μ-hydroxido-κ4O:O-dinitrato-κ4O:O′-bis[3-(pyridin-4-yl-κN-5-(pyridin-3-yl-1,2,4-oxadiazole]dicopper(II

Directory of Open Access Journals (Sweden)

Longfei Wu

2012-04-01

Full Text Available The title compound, [Cu2(NO32(OH2(C12H8N4O2(H2O2]n, consists of a neutral polymeric CuII complex in which each CuII atom has a distorted octahedral geometry defined by a pyridyl N atom from a 3-(pyridin-3-yl-5-(pyridin-4-yl-1,2,4-oxadiazole ligand and five O atoms from a water molecule, two nitrates and two hydroxides. Two CuII ions are bridged by two hydroxide anions resulting in a Cu2O2 loop, located across an inversion center and connected by the nitrate anions into a broad two-dimensional polymeric structure parallel to (100. In the crystal, there are O—H...O hydrogen bonds between the coodinated water molecule and the nitrate and hydroxide, and between the hydroxide and the nitrate. Intermolecular π–π interactions are present between pyridine rings in adjacent two-dimensional structures, with a centroid–centroid distance of 3.582 (2 Å.

Effect of organoelemental compounds of group 3 elements on radical polymerization of vinyl monomers

International Nuclear Information System (INIS)

Grishin, D.F.; Mojkin, A.A.

1996-01-01

When alkyl, alkyl alkoxy, and alkyl halide derivatives of boron and aluminium are introduced into the system in amounts that are comparable to the concentration of initiator, they coordinate to the growing macroradicals, thus changing their reactivity, and exert regulating effect on the rate of polymerization of vinyl monomers and the molecular mass of the resulting polymers. The said organoelemental compounds accelerate the polymerization of butyl acrylate, methyl methacrylate, acrylonitrile, vinyl acetate, and vinylidene chloride, reduce the molecular mass of acrylic polymers, and virtually do not affect the polymerization of styrene. The specific features of vinyl polymerization are associated with participation of organoelemental additives at the stages of chain growth and chain termination and can be explained within the framework of the mechanism of radical-coordination polymerization. 32 refs., 3 tabs

Surface modification of thermoplastic poly(vinyl alcohol)/saponite nanocomposites via surface-initiated atom transfer radical polymerization enhanced by air dielectric discharges barrier plasma treatment

International Nuclear Information System (INIS)

Zhen Weijun; Lu Canhui

2012-01-01

To improve the water resistance of thermoplastic poly(vinyl alcohol)/saponite nanocomposites (TPVA), a simple two-step method was developed for the covalent immobilization of atom transfer radical polymerization (ATRP) initiators on the TPVA surfaces enhanced by air dielectric barrier discharges (DBD) plasma treatment, and hydrophobic poly(methyl methacrylate) (PMMA) brushes were then grafted onto the surface of TPVA via surface-initiated atom transfer radical polymerization (SI-ATRP). The chemical composition, morphology and hydrophobicity of the modified TPVA surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), respectively. The water resistance of the surface-functionalized PMMA was evaluated by the contact angle and water adsorption method. It was shown that air DBD plasma treatment activated the TPVA surface and accelerated the immobilization of ATRP initiator on the TPVA surface. Compared with TPVA control, TPVA modified by SI-ATRP can be grafted well-defined and covalently tethered network PMMA brushes onto the surface and the hydrophobicity of TPVA were significantly enhanced.

Poly[bis[μ-4-(4-carboxyphenoxybenzoato](μ-4,4′-oxydibenzoatobis[μ-3-(pyridin-4-yl-5-(pyridin-3-yl-1H-1,2,4-triazole]dicadmium(II

Directory of Open Access Journals (Sweden)

Xiao-Jin Qi

2016-07-01

Full Text Available Three kinds of bridging ligands, 4,4′-oxydibenzoate, 4-(4-carboxyphenoxybenzoate and 3-(pyridin-4-yl-5-(pyridin-3-yl-1H-1,2,4-triazole, link the CdII cations to form the title polymeric complex, [Cd2(C14H8O5(C14H9O52(C12H9N52]n, in which each CdII cation is in a distorted N2O5 pentagonal–bipyramidal coordination geometry. The 4,4′-oxydibenzoate dianion exhibits point group symmetry 2, with the central O atom located on a twofold rotation axis. Classical N—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds link the complex molecules into a three-dimensional supramolecular architecture. A solvent-accessible void of 53 (2 Å3 is observed, but no solvent molecule could reasonably located there.

Preparation of poly(vinyl alcohol)/kaolinite nanocomposites via in situ polymerization

International Nuclear Information System (INIS)

Jia Xin; Li Yanfeng; Zhang Bo; Cheng Qiong; Zhang Shujiang

2008-01-01

Poly(vinyl alcohol)/kaolinite intercalated nanocomposites (Kao-PVA) were prepared via in situ intercalation radical polymerization. Vinyl acetate (VAc) was intercalated into kaolinite by a displacement method using dimethyl sulfoxide/kaolinite (Kao-DMSO) as the intermediate. Then, PVAc/kaolinite (Kao-PVAc) was obtained via radical polymerization with benzoyl peroxide (BPO) as initiator. Last, PVAc/kaolinite was saponified via direct-hydrolysis with NaOH solution in order to obtain PVA/kaolinite nanocomposites, which was characterized by Fourier-Transformation spectroscopy (FTIR), wide X-ray diffraction (WXRD) and transmission electron microscopy (TEM). Their differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) results of the obtained PVA/kaolinite suggested that the thermal properties had an obvious improvement

The inhibition mechanisms of quinones and phenols present in wood for the vinyl polymerization

International Nuclear Information System (INIS)

Nobashi, Kenzo; Yokota, Tokuo

1977-01-01

The inhibitory effects and mechanisms of the quinones and phenols present in wood for the vinyl polymerization initiated with γ-rays and other initiation systems were investigated. The results obtained are summarized as follows; (1) Although phenolic compounds like isotaxiresinol inhibit the γ-ray initiated polymerization of methyl methacrylate (MMA) under the presence of air, they have no inhibitory effects in vacuo. On the other hand, o-benzoquinone and mansonones show strong inhibitory or retarding effects in vacuo. These facts indicate that oxygen may be important for the phenols to inhibit the vinyl polymerization. (2) It is shown qualitatively that there is a relationship between the strength of inhibitory action of quinones and their normal redox potentials. (3) PMMA produced under the presence of o-benzoquinone is found to include the fraction having extremely large chain length based on gel permeation chromatogram. (4) Based on the reaction products of orthoquinones and azobisisobutyronitrile, which was assumed as a model of polymer radicals, the inhibition reaction with polymer chain radical is concluded to take place upon the oxygen atoms of the quinones. (auth.)

Method of modifying a vinyl chloride resin by utilizing radiation cross-linking polymerization

Energy Technology Data Exchange (ETDEWEB)

Kagiya, T; Fujimoto, T; Hosoi, F; Tsuneta, K; Atogawa, M

1970-08-26

The polyvinyl chloride is improved in its mechanical, thermal and chemical properties, with particular advantages gained in dimensional stability at temperatures higher than the plasticizing temperature. The process comprises irradiating a vinyl chloride resin with ionizing radiations in the presence of a vinyl acetate monomer. In this process, the irradiation of vinyl acetate effects cross-linking and the polymerization of the monomer simultaneously. The vinyl chloride resin may be a copolymer along with another monomer, a polyvinyl chloride derivative, a graft polymer of polyvinyl chloride, a mixture of vinyl chloride with another resin and a graft copolymer of vinyl chloride on another resin in any form. The addition of the vinyl acetate monomer to the vinyl chloride is not limited to any particular procedure. The vinyl acetate monomer may be added to the polyvinyl chloride in a quantity ranging from a trace to 200% by weight. The radiation dose may be 10/sup 2/ to 10/sup 9/, but preferably 10/sup 3/ roentgen. In one example, 36 parts by weight of market available vinyl acetate monomer immersed in 100 parts by weight of hard vinyl tube were placed in a stainless reacting vessel. After the replacement of inner air with nitrogen, the vessel was exposed to ..gamma.. beams of 4.8 x 10 roentgen from a Co-60 source. After dipping the exposed samples in boiled tetrahydrofuran for 48 hours, the insoluble substance in the samjle was 78.9% by weight. In addition, after heating at 180/sup 0/C for 30 minutes, the sample did not show any deformation.

Vinyl Chloride Emulsion Polymerization Reaction: Effect of Various Formulations

Directory of Open Access Journals (Sweden)

Seyed Mehrdad Jalilian

2013-01-01

Full Text Available A mixture  of  sodium  lauryl  sulfate  (SLS  as  ionic  emulsifer  and  stearyl alcohol as non-ionic emulsifer was employed in a vinyl chloride emulsion polymerization  reaction  to  study  the  infuence  of  various  interactive parameters involved in the reaction system. It was found that the particle size was dependent on the amount and type of emulsifer. The average particle size of polyvinyl chloride was dropped by higher amount of emulsifying agents.  At the gel point, more heat was generated by higher amount of vinyl chloride fed into the reaction system. The molecular weight of the polymer was decreased by increases in reaction temperature while,  it  increased by augmenting  the amount of emulsifer. According to the 13C NMR and FTIR spectroscopic data no defect was detected in the chain structure of synthetic polyvinylchloride product. An optimization of polymerization reaction condition was reached based on ultimate particle size desired for its favorable distribution in plastisols.

Poly[μ2-aqua-aqua-μ4-pyridine-2,4-dicarboxylato-strontium

Directory of Open Access Journals (Sweden)

Zohreh Derikvand

2009-08-01

Full Text Available In the title polymeric complex, [Sr(C7H3NO4(H2O2]n, the SrII atom is eight-coordinated by four O atoms and one N atom of four pyridine-2,4-dicarboxylate (py-2,4-dc ligands and three O atoms of three coordinated water molecules in a dodecahedral geometry. These units are connected via the carboxylate O atoms and water molecules, building polymeric layers parallel to (100. In the crystal structure, non-covalent interactions consisting of O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.862 (17 and 3.749 (17 Å] connect the various components, forming a three-dimensional structure.

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol) and poly (vinyl alcohol)/silica using indigenous electrospinning set up

International Nuclear Information System (INIS)

Sasipriya, K.; Suriyaprabha, R.; Prabu, P.; Rajendran, V.

2013-01-01

Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol fibers were characterized by Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and Fourier transform infra red spectroscopy (FTIR). According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol) fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up. (author)

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol) and poly (vinyl alcohol)/silica using indigenous electrospinning set up

Energy Technology Data Exchange (ETDEWEB)

Sasipriya, K.; Suriyaprabha, R.; Prabu, P.; Rajendran, V., E-mail: veerajendran@gmail.com [Centre for Nanoscience and Technology, K. S. Rangasamy College of Technology, Tamil Nadu (India)

2013-11-01

Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol) and poly (vinyl alcohol)/silica sol fibers were characterized by Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and Fourier transform infra red spectroscopy (FTIR). According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol) fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up. (author)

Synthesis and characterisation of polymeric nanofibers poly (vinyl alcohol and poly (vinyl alcohol/silica using indigenous electrospinning set up

Directory of Open Access Journals (Sweden)

K. Sasipriya

2013-01-01

Full Text Available Indigenous design and fabrication horizontal of electrospinning set up was developed to facilitate with double drum conveyor belt system to make ease in harvesting nanofibers rapidly. As a bench mark study, organic-inorganic nanofiber composite was synthesised employing our indigenous electrospinning set up. The aqueous solution of poly (vinyl alcohol and poly (vinyl alcohol/silica sol were employed to produce nanofiber mats in order to vary the experimental parameters such as voltage, solvent effect and the effect of catalyst. The synthesised pure electro spun poly (vinyl alcohol and poly (vinyl alcohol/silica sol fibers were characterized by Scanning electron microscopy (SEM, Atomic force microscopy (AFM and Fourier transform infra red spectroscopy (FTIR. According to the results, the fine polymeric nanofibers were achieved in the size range of 100-500 nm for pure poly (vinyl alcohol fiber and 100-700 nm for polyvinyl alcohol/silica and the constitution of silica in rendering better fiber mats with this double drum set up.

2-Aminobenzoic acid–4-(pyridin-4-yldisulfanyl)pyridine (1/1)

OpenAIRE

Hadi D. Arman; Trupta Kaulgud; Edward R. T. Tiekink

2011-01-01

The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanyl)pyridine molecule [dihedral angle between the pyridine rings = 89.06 (10)°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3)°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O&#...

The Contrasting Alkylations of 4-(Dimethylaminomethyl)pyridine and 4-(Dimethylamino)pyridine: An Organic Chemistry Experiment

Science.gov (United States)

Jantzi, Kevin L.; Wiltrakis, Susan; Wolf, Lauren; Weber, Anna; Cardinal, Josh; Krieter, Katie

2011-01-01

A critical factor for the increased nucleophilicity of the pyridine nitrogen in 4-(dimethylamino)pyridine (DMAP) is electron donation via resonance from the amino group into the aromatic ring that increases electron density on the pyridine nitrogen. To explore how important this resonance effect is, 4-(dimethylaminomethyl)pyridine (DMAMP) was…

Simultaneous FT-NIR and ESR analysis to study of the kinetics of photo induced polymerization of vinyl radical polymers

International Nuclear Information System (INIS)

Le, T.T.; Hill, D.J.T.; Pomery, P.J.

2000-01-01

Full text:The rate parameters for free vinyl radical polymerizations are difficult to determine accurately over the whole range of conversion. For systems which polymerize rapidly and for networks, this is a particular problem, because small differences in polymerization conditions, e.g., temperature, initiator concentration, photon flux, etc., can cause a large change in the time evolution of the concentration of carbon double bonds and radicals if these are monitored in separate experiments. The IUPAC Working Party on the Modeling of kinetics and processes of polymerization has the role of recommending the 'best' values for the kinetic parameters, using pulsed-laser polymerization (PLP) in conjunction with molar mass distribution (MMD) to determine k p as a function of temperature (T deg C) for bulk free-radical polymerization of methyl methacrylate at low conversions and ambient temperature. The vinyl radical polymers used in this study were methyl methacrylate and ethylene glycol dimethacrylate. In the past kinetic studies of vinyl photo-polymerization required the time dependence of the monomer and radical concentrations to be monitored separately by using FT-NIR spectroscopy and ESR spectroscopy, respectively. For the systems which polymerize rapidly, small differences in the conditions for two measurements, e.g. temperature and light intensity, can introduce significant errors. Hyphenated experiments involving in-situ ESR and FT-NIR spectroscopies using fibre optic, can overcome these problems. In this paper, the radical and monomer concentrations were measured under the same experimental conditions using the above techniques. The results obtained were used to evaluate the kinetic parameters for free radical vinyl polymerizations

Copolymers of Vinyl-Containing Benzoxazine with Vinyl Monomers as Precursors for High Performance Thermosets

Directory of Open Access Journals (Sweden)

Tsutomu Takeichi

2015-04-01

Full Text Available A benzoxazine containing a vinyl group (P-4va was prepared by the reaction of phenol, 4-vinylaniline, and paraformaldehyde. A differential scanning calorimetry (DSC study revealed that ring-opening polymerization of the benzoxazine and chain polymerization of the vinyl group occurred in the same temperature range. When 2,2'-azobisisobutyronitrile was added as a radical initiator to P-4va, however, only the vinyl groups were polymerized at lower temperature, giving oligo(P-4va that contains pendent benzoxazine units. Radical copolymerization of P-4va with various vinyl monomers such as styrene, methyl methacrylate (MMA, and n-butyl acrylate (BuA was examined. The chemical structure of the copolymers was confirmed by FT-IR and 1H-NMR to be one of polyolefins bearing benzoxazine units as the pendant groups. The weight-average molecular weights of the copolymers determined by size exclusion chromatography were to be in the range of 1900–51,500 depending on the comonomers. DSC of the copolymers showed that the maxima of the exothermic peaks corresponding to the ring-opening polymerization of the pendent benzoxazine units were observed in the temperature range of 229–250 °C. Thermal cure up to 240 °C of the copolymer films afforded homogenous transparent films with improved thermal properties. Tough cured film was obtained by the copolymerization with MMA, while a tough and flexible film was obtained by the copolymerization with BuA.

Two polymeric nickel(II) complexes with aromatic benzene-1,2,4,5-tetracarboxylate and pyridine-2,5-dicarboxylate linkers.

Science.gov (United States)

Atria, Ana María; Corsini, Gino; González, Lissette; Garland, Maria Teresa; Baggio, Ricardo

2009-07-01

(Mu-benzene-1,2,4,5-tetracarboxylato-kappa(2)O(1):O(4))bis[aquabis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)] methanol disolvate tetrahydrate, [Ni(2)(C(10)H(2)O(8))(C(5)H(14)N(2))(4)(H(2)O)(2)].2CH(4)O.4H(2)O, (I), is dinuclear, with elemental units built up around an inversion centre halving the benzene-1,2,4,5-tetracarboxylate (btc) anion, which bridges two symmetry-related Ni(II) cations. The octahedral Ni polyhedron is completed by two chelating 2,2-methylpropane-1,3-diamine (dmpda) groups and a terminal aqua ligand. Two methanol and four water solvent molecules are involved in a number of N-H...O and O-H...O hydrogen bonds which define a strongly bound two-dimensional supramolecular structure. The structure of catena-poly[[[bis(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)O(5):N,O(2)-[(2,2-methylpropane-1,3-diamine-kappa(2)N,N')nickel(II)]-mu-pyridine-2,5-dicarboxylato-kappa(3)N,O(2):O(5)] octahydrate], {[Ni(2)(C(7)H(3)NO(4))(2)(C(5)H(14)N(2))(3)].8H(2)O}(n), (II), is polymeric, forming twisted chains around three independent Ni centres, two of which lie on inversion centres and the third in a general position. There are three chelating dmpda ligands (one disordered over two equally populated positions), which are each attached to a different cation, and two pyridine-2,5-dicarboxylate (pdc) anions, both chelating the Ni centre in general positions through an -O-C-C-N- loop, while acting as bridges to the remaining two centrosymmetric Ni atoms. There are, in addition, eight noncoordinated water molecules in the structure, some of which are disordered.

FT-IR Spectroscopic study on the 4-(3-Cyclohexen-1-yl)pyridine metal (II) tetracyanonickelate complex

International Nuclear Information System (INIS)

Parlak, C.

2005-01-01

New Hofmann type complex in the form of M(4-Chpy) 2 Ni(CN) 4 (where 4-Chpy=4-(3- Cyclohexen-1-yl)pyridine and M = Ni) was prepared in powder form and its infrared spectra is reported in the range of 4000-400 cm - 1. The spectral findings suggest that this compound is similar in structure to the Hofmann type complexes and its structure consists of polymeric layers | M-Ni(CN) 4 |∞ with the 4-(3-Cyclohexen-1-yl)pyridine molecule bound to the metal atom (M)

Preparation of poly(vinyl alcohol)-grafted graphene oxide/poly(vinyl alcohol) nanocomposites via in-situ low-temperature emulsion polymerization and their thermal and mechanical characterization

Science.gov (United States)

Zhang, Shengchang; Liu, Pengqing; Zhao, Xiangsen; Xu, Jianjun

2017-02-01

An in-situ polymerization combined with chemical grafting modification method for preparing Poly(vinyl alcohol)-grafted graphene oxide/Poly(vinyl alcohol) (PVA-g-GO/PVA) nanocomposites was reported. Firstly, Poly(vinyl acetate)-grafted graphene oxide/Poly(vinyl acetate) nanocomposites were prepared, and then the PVA-g-GO/PVA nanocomposites could be obtained through alcoholysis reaction. X-ray photoelectron spectrometer and fourier-transform infrared spectrometer confirmed that the PVAc or PVA chains were successfully grafted to GO sheets during in-situ polymerization and alcoholysis. And the results from transmission electron microscopy, scanning electron microscopy and X-ray diffraction showed that the well compatibility and homogenous dispersion of PVA-g-GO in PVA matrix could be achieved. Differential scanning calorimetric, thermogravimetry analysis and tensile test were employed to study the thermal and mechanical properties of the PVA-g-GO/PVA nanocomposites. The results indicated that a 53% improvement of tensile strength and a 36% improvement of Young's modulus were achieved by addition of 0.5 wt% of GO sheets. And the glass transition temperature of PVA-g-GO/PVA nanocomposites was increased, and their thermal stability and crystallization degree were both decreased. Due to well dispersion of fillers and strong interfacial interactions at the filler-matrix interface, in-situ polymerization combined with chemical grafting modification was a good choice to prepare graphene/PVA nanocomposite with excellent mechanical properties.

Preparation of poly(vinyl alcohol)-grafted graphene oxide/poly(vinyl alcohol) nanocomposites via in-situ low-temperature emulsion polymerization and their thermal and mechanical characterization

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shengchang; Liu, Pengqing, E-mail: liupq@scu.edu.cn; Zhao, Xiangsen; Xu, Jianjun, E-mail: xujj@scu.edu.cn

2017-02-28

Highlights: • In-situ emulsion polymerization and alcoholysis reaction is a good method to prepare GO/PVA nanocomposites. • Surface chemical grafting modification of GO with PVA chains was also carried out during the in-situ emulsion polymerization and alcoholysis reaction. • The surface chemical grafting modification of GO by in-situ polymerization and alcoholysis reaction could not only improve the dispersion of fillers in matrix, but also the interfacial interactions between fillers and matrix. • The thermal and mechanical properties of PVA-g-GO/PVA nanocompistes were also studied. - Abstract: An in-situ polymerization combined with chemical grafting modification method for preparing Poly(vinyl alcohol)-grafted graphene oxide/Poly(vinyl alcohol) (PVA-g-GO/PVA) nanocomposites was reported. Firstly, Poly(vinyl acetate)-grafted graphene oxide/Poly(vinyl acetate) nanocomposites were prepared, and then the PVA-g-GO/PVA nanocomposites could be obtained through alcoholysis reaction. X-ray photoelectron spectrometer and fourier-transform infrared spectrometer confirmed that the PVAc or PVA chains were successfully grafted to GO sheets during in-situ polymerization and alcoholysis. And the results from transmission electron microscopy, scanning electron microscopy and X-ray diffraction showed that the well compatibility and homogenous dispersion of PVA-g-GO in PVA matrix could be achieved. Differential scanning calorimetric, thermogravimetry analysis and tensile test were employed to study the thermal and mechanical properties of the PVA-g-GO/PVA nanocomposites. The results indicated that a 53% improvement of tensile strength and a 36% improvement of Young’s modulus were achieved by addition of 0.5 wt% of GO sheets. And the glass transition temperature of PVA-g-GO/PVA nanocomposites was increased, and their thermal stability and crystallization degree were both decreased. Due to well dispersion of fillers and strong interfacial interactions at the filler

Preparation of poly(vinyl alcohol)-grafted graphene oxide/poly(vinyl alcohol) nanocomposites via in-situ low-temperature emulsion polymerization and their thermal and mechanical characterization

International Nuclear Information System (INIS)

Zhang, Shengchang; Liu, Pengqing; Zhao, Xiangsen; Xu, Jianjun

2017-01-01

Highlights: • In-situ emulsion polymerization and alcoholysis reaction is a good method to prepare GO/PVA nanocomposites. • Surface chemical grafting modification of GO with PVA chains was also carried out during the in-situ emulsion polymerization and alcoholysis reaction. • The surface chemical grafting modification of GO by in-situ polymerization and alcoholysis reaction could not only improve the dispersion of fillers in matrix, but also the interfacial interactions between fillers and matrix. • The thermal and mechanical properties of PVA-g-GO/PVA nanocompistes were also studied. - Abstract: An in-situ polymerization combined with chemical grafting modification method for preparing Poly(vinyl alcohol)-grafted graphene oxide/Poly(vinyl alcohol) (PVA-g-GO/PVA) nanocomposites was reported. Firstly, Poly(vinyl acetate)-grafted graphene oxide/Poly(vinyl acetate) nanocomposites were prepared, and then the PVA-g-GO/PVA nanocomposites could be obtained through alcoholysis reaction. X-ray photoelectron spectrometer and fourier-transform infrared spectrometer confirmed that the PVAc or PVA chains were successfully grafted to GO sheets during in-situ polymerization and alcoholysis. And the results from transmission electron microscopy, scanning electron microscopy and X-ray diffraction showed that the well compatibility and homogenous dispersion of PVA-g-GO in PVA matrix could be achieved. Differential scanning calorimetric, thermogravimetry analysis and tensile test were employed to study the thermal and mechanical properties of the PVA-g-GO/PVA nanocomposites. The results indicated that a 53% improvement of tensile strength and a 36% improvement of Young’s modulus were achieved by addition of 0.5 wt% of GO sheets. And the glass transition temperature of PVA-g-GO/PVA nanocomposites was increased, and their thermal stability and crystallization degree were both decreased. Due to well dispersion of fillers and strong interfacial interactions at the filler

Radiation grafting of pH-sensitive acrylic acid and 4-vinyl pyridine onto nylon-6 using one- and two-step methods

International Nuclear Information System (INIS)

Ortega, Alejandra; Alarcón, Darío; Muñoz-Muñoz, Franklin; Garzón-Fontecha, Angélica; Burillo, Guillermina

2015-01-01

Acrylic acid (AAc) and 4-vinyl pyridine (4VP) were γ-ray grafted onto nylon-6 (Ny 6 ) films via pre-irradiation oxidative method. These monomers were grafted using a one-step method to render Ny 6 -g–(AAc/4VP). A two-step or sequential method was used to render (Ny 6 -g–AAc)-g–4VP. Random copolymer branches were obtained when the grafting was carried out via one-step method using the two monomers together. The two-step method was applied to graft chains of 4VP on both Ny 6 substrate and previously grafted AAc chains (Ny 6 -g–AAc). The two types of binary copolymers synthesized were characterized to determine the amount of grafted polymers, the thermal behavior (DSC and TGA), the surface composition (XPS), and the pH responsiveness. In the two-step process, it is possible to achieve a higher graft yield, better control of the amount of each monomer, good reversibility in the swelling/deswelling process and shorter time to achieve equilibrium swelling. - Highlights: • A new binary graft of 4VP and AAc onto Ny 6 films was synthesized by γ-radiation. • The binary grafted material has potential application for heavy ion retention. • The two-step method shows better conditions in swelling and reversibility properties. • Surface distribution of monomers was evaluate by XPS characterization

Nuclear magnetic resonance and relaxation studies of the structure and segmental motions of 4-vinyl-pyridinic polymers in solution

International Nuclear Information System (INIS)

Ghesquiere, Denis

1978-01-01

The poly 4-vinylpyridine, its quaternized products from HBr and n-alkyl-bromides, and its N-oxide form have been investigated by nuclear magnetic resonance of proton at 100 and 250 MHz and carbon-13 at 25.15 MHz, The 1 H and 13 C relaxation data of poly-vinylpyridine and its ionized form have been correlated with conformational calculations. They have been interpreted in terms of an isotropic motion of the macromolecular segments introducing a correlation times distribution and of an oscillation motion of the pyridyl groups. The same treatment have been used for the 13 C relaxation data of the poly 4- vinyl-pyridines quaternized at various rates by n-alkyl-bromides. The 13 C relaxation times in the side-chains have been interpreted first by semi-empirical equations assuming an exponential gradient of the diffusion coefficients along them, and also by a Monte Carlo simulation of the motions. The results have shown that the quaternization induces a strong rigidity of the macromolecular backbone and that the dominant effect is the electrostatic interactions. On the other hand it seems that the motion of pyridyl rings is not affected. Moreover we have found a range of oscillation amplitudes in agreement with conformational energy calculations and the results obtained from a conformational study of the poly 4-vinylpyridine N-oxide by 1 H and 13 C NMR contact shifts induced by Ni II paramagnetic ions. (author) [fr

A new lithography of functional plasma polymerized thin films

International Nuclear Information System (INIS)

Kim, Sung-O

2001-01-01

The preparation of the resist for the vacuum lithography was carried out by plasma polymerization. The resist manufactured by plasma polymerization is a monomer produced by MMA (Methyl methacrylate). The functional groups of MMA appeared in the PPMMA (Plasma Polymerized Methyl methacrylate) as well, and this was confirmed through an analysis using FT-IR. The polymerization rate increased as a function of the plasma power and decreased as a function of the system pressure. The sensitivity and contrast of the plasma polymerized thin films were 15 μC/cm2 and 4.3 respectively. The size of the pattern manufactured by Vacuum Lithography using the plasma polymerized thin films was 100 nm

Effect of monomer concentration on the kinetics of emulsifier-free emulsion polymerization of Vinyl Acetate and Methyl Acrylate

International Nuclear Information System (INIS)

Mohammad Beigi, H. R.

2001-01-01

The effect of monomer concentration on the kinetics of the emulsifier-free emulsion polymerization of vinyl acetate and methyl acrylate were studied. The polymerizations were carried out using potassium persulfate as the initiator. Form the electron micrographs of the resulting lattices, monodisperse PVAc and PMA lattices with particle diameters varying between 149-443 mm and 112-497 nm, respectively were processed. Uniformity of particle size indicated that nucleation of stable particle occurs early in the polymerization process. The polymerization rate was found to be proportional to the 0.88 and 1.5 power of the initial monomer concentration of vinyl acetate and methyl acrylate, respectively. Higher monomer concentration results in fewer particles and larger final particle diameter. With increasing monomer solubility in water the size of particle decreases and its distribution broadens

Optimal control of batch emulsion polymerization of vinyl chloride

Energy Technology Data Exchange (ETDEWEB)

Damslora, Andre Johan

1998-12-31

The highly exothermic polymerization of vinyl chloride (VC) is carried out in large vessels where the heat removal represents a major limitation of the production rate. Many emulsion polymerization reactors are operated in such a way that a substantial part of the heat transfer capacity is left unused for a significant part of the total batch time. To increase the reaction rate so that it matches the heat removal capacity during the course of the reaction, this thesis proposes the use of a sufficiently flexible initiator system to obtain a reaction rate which is high throughout the reaction and real-time optimization to compute the addition policy for the initiator. This optimization based approach provides a basis for an interplay between design and control and between production and research. A simple model is developed for predicting the polymerization rate. The model is highly nonlinear and open-loop unstable and may serve as an interesting case for comparison of nonlinear control strategies. The model is fitted to data obtained in a laboratory scale reactor. Finally, the thesis discusses optimal control of the emulsion polymerization reactor. Reduction of the batch cycle time is of major economic importance, as long as the quality parameters are within their specifications. The control parameterization had a major influence on the performance. A differentiable spline parameterization was applied and the optimization is illustrated in a number of cases. The best performance is obtained when the reactor temperature is obtained when the optimization is combined with some form of closed-loop control of the reactor temperature. 112 refs., 48 figs., 4 tabs.

Impact of Industrial Grade Modified PVA to Vinyl Acetate Semi-continuous Emulsion Polymerization and Properties of Final Product

Directory of Open Access Journals (Sweden)

Mindaugas DUBININKAS

2013-03-01

Full Text Available Successful vinyl acetate radical emulsion polymerization in water with different type of industrial grade poly(vinyl alcohol were produced by semi continuous way. The poly(vinyl alcohol type has crucial impact on dispersion rheological as well on films and bonding strength properties. It should be stated that the films containing modified poly (vinyl alcohol has better water resistance and mechanical properties. Poly(vinyl alcohol with higher ethylene moieties content and high hydrolization degree determines extremely low viscosity of final dispersion.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3823

Synthesis and characterization of copolymers from hindered amines and vinyl monomers

Directory of Open Access Journals (Sweden)

Marcelo Aparecido Chinelatto

2014-01-01

Full Text Available New copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP and acrylate-(4ATP monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty using 1-butanethiol (BTN resulted in a copolymer with 95 units of Sty and 15 units of 1ATP. The radical chain polymerization of 1ATP and vinyl acetate (VAc has produced only 1ATP homopolymer. In the chain polymerization of 4ATP with Sty or VAc, the hydrogen atom bonded to the nitrogen of 4ATP is labile enough to originate another radical at this site. The steric hindrance imposed by methyl groups on this bonding site hampers its reaction with other propagating species and the formation of a copolymer or network structure will be dependent on the size of the pendent group in the vinyl monomer.

Halloysite nanotubes grafted hyperbranched (co)polymers via surface-initiated self-condensing vinyl (co)polymerization

International Nuclear Information System (INIS)

Mu Bin; Zhao Mingfei; Liu Peng

2008-01-01

Halloysite nanotubes (HNTs) grafted hyperbranched polymers were prepared by the self-condensing vinyl polymerization (SCVP) of 2-((bromoacetyl)oxy)ethyl acrylate (BAEA) and the self-condensing vinyl copolymerization of n-butyl acrylate (BA) and BAEA with BAEA as inimer (AB*) respectively, from the surfaces of the 2-bromoisobutyric acid modified halloysite nanotubes (HNTs-Br) via atom transfer radical polymerization (ATRP) technique. The halloysite nanotubes grafted hyperbranched polymer (HNTs-HP) and the halloysite nanotubes grafted hyperbranched copolymer (HNTs-HCP) were characterized by elemental analysis (EA), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscope (TEM). The grafted hyperbranched polymers were characterized with Nuclear magnetic resonance (NMR) and the molecular ratio between the inimer AB* and BA in the grafted hyperbranched copolymers was found to be 3:2, calculated from the TGA and EA results

Halloysite nanotubes grafted hyperbranched (co)polymers via surface-initiated self-condensing vinyl (co)polymerization

Energy Technology Data Exchange (ETDEWEB)

Mu Bin; Zhao Mingfei; Liu Peng [Lanzhou University, State Key Laboratory of Applied Organic Chemistry and Institute of Polymer Science and Engineering, College of Chemistry and Chemical Engineering (China)], E-mail: pliu@lzu.edu.cn

2008-05-15

Halloysite nanotubes (HNTs) grafted hyperbranched polymers were prepared by the self-condensing vinyl polymerization (SCVP) of 2-((bromoacetyl)oxy)ethyl acrylate (BAEA) and the self-condensing vinyl copolymerization of n-butyl acrylate (BA) and BAEA with BAEA as inimer (AB*) respectively, from the surfaces of the 2-bromoisobutyric acid modified halloysite nanotubes (HNTs-Br) via atom transfer radical polymerization (ATRP) technique. The halloysite nanotubes grafted hyperbranched polymer (HNTs-HP) and the halloysite nanotubes grafted hyperbranched copolymer (HNTs-HCP) were characterized by elemental analysis (EA), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscope (TEM). The grafted hyperbranched polymers were characterized with Nuclear magnetic resonance (NMR) and the molecular ratio between the inimer AB* and BA in the grafted hyperbranched copolymers was found to be 3:2, calculated from the TGA and EA results.

2-Aminobenzoic acid–4-[2-(pyridin-4-ylethyl]pyridine (2/1

Directory of Open Access Journals (Sweden)

Hadi D. Arman

2013-11-01

Full Text Available The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-ylethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6°] despite the presence of an intramolecular N—H...O(carbonyl hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl hydrogen bonds, and these are connected into supramolecular layers in the bc plane by N—H...O(carbonyl hydrogen bonds and π–π interactions between pyridine and benzene rings [inter-centroid distance = 3.6332 (9 Å]. Layers are connected along the a axis by weak π–π interactions between benzene rings [3.9577 (10 Å].

Concurrent coordination of ligand in metal chloride complexes with 1-vinyl-2-(2-pyridyl)benzimidazole

International Nuclear Information System (INIS)

Bajkalov, L.V.; Domnina, E.S.

1996-01-01

The properties and structure of bivalent cadmium and 1-vinyl-2-(2-pyridyl)benzimidazole chloride complexes, which have been prepared for the first time, have been studied by the methods of potentiometric titration and PMR, 35 Cl NQR, UV and IR spectroscopy. For the complexes above di- and polymeric structures in crystal phase are suggested, where ligand plays the role of a bridge. N,N-bidentate ligand. In solution the complexes dissociate with formation of monomeric coordination compounds, their metal being bound by different ways, stemming from participation of N benzimidazole or pyridine fragment of the ligand. Adducts of ionic type with second sphere 1-vinyl-2-(2-pyridyl)benzimidazole cation have been obtained in the course of hydrochlorination of the complexes prepared

Inclusion polymerization of vinyl chloride monomer in deoxycholic acid host via {gamma}-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Chirachanchai, S.; Kumkrong, A. [The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok (Thailand); Ishida, Hatsuo [Department of Macromolecular Science, Case Western Reserve University, Cleveland, OH (United States)

2000-03-01

Inclusion polymerization of vinyl chloride monomer (VCM) was studied in the system of 3{alpha}, 12{alpha} -dihydroxy-5{beta}-cholan-24-oic acid (deoxycholic acid, DCA). DCA-VCM inclusion compound system was originally prepared by guest intercalation technique in DCA guest free crystal. The inclusion polymerization of DCA-VCM by {gamma}-irradiation at total dose 2 Mrad, gives a syndiotactic rich polyvinyl chloride (PVC) as can be confirmed by FT-IR and FT-NMR. (author)

Inclusion polymerization of vinyl chloride monomer in deoxycholic acid host via γ-ray irradiation

International Nuclear Information System (INIS)

Chirachanchai, S.; Kumkrong, A.; Ishida, Hatsuo

2000-01-01

Inclusion polymerization of vinyl chloride monomer (VCM) was studied in the system of 3α, 12α -dihydroxy-5β-cholan-24-oic acid (deoxycholic acid, DCA). DCA-VCM inclusion compound system was originally prepared by guest intercalation technique in DCA guest free crystal. The inclusion polymerization of DCA-VCM by γ-irradiation at total dose 2 Mrad, gives a syndiotactic rich polyvinyl chloride (PVC) as can be confirmed by FT-IR and FT-NMR. (author)

Novel polymer coatings based on plasma polymerized 2-methoxyethyl acrylate

DEFF Research Database (Denmark)

Wu, Zhenning; Jiang, Juan; Benter, Maike

2008-01-01

plasma system[4]. The system named SoftPlasma™ is equipped with unique three-phase pulsed AC voltage. Low energy plasma polymerization has almost no thermal load for sensitive polymer materials[5]. Plasma polymerized coatings are highly cross-linked, pin-hole free and provide hydrophilic or hydrophobic...... properties[4-6]. We have exploited these possibilities and prepared plasma polymerized 2-methoxyethyl acrylate (PPMEA) coatings on various polymer substrates. The PPMEA coatings were optimized using various plasma polymerization conditions and characterized by X-ray photoelectron spectroscopy......, Fouriertransform infrared spectroscopy, Atomic force spectroscopy and Water contact-angle measurements. The microstructures ofPPMEA coatings with different thicknesses were also studied. For practical applications in mind, the coating stability was tested in different media (air, water, acetone, phosphate...

Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

KAUST Repository

Vidal, Fernando

2016-07-07

The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

Robust Crosslinked Stereocomplexes and C60 Inclusion Complexes of Vinyl-Functionalized Stereoregular Polymers Derived from Chemo/Stereoselective Coordination Polymerization

KAUST Repository

Vidal, Fernando; Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Chen, Eugene Y.-X.

2016-01-01

The successful synthesis of highly syndiotactic polar vinyl polymers bearing the reactive pendant vinyl group on each repeat unit, which is enabled by perfectly chemoselective and highly syndiospecific coordination polymerization of divinyl polar monomers developed through this work, has allowed the construction of robust crosslinked supramolecular stereocomplexes and C60 inclusion complexes. The metal-mediated coordination polymerization of three representative polar divinyl monomers, including vinyl methacrylate (VMA), allyl methacrylate (AMA), and N,N-diallyl acrylamide (DAA) by Cs-ligated zirconocenium ester enolate catalysts under ambient conditions exhibits complete chemoselectivity and high stereoselectivity, thus producing the corresponding vinyl-functionalized polymers with high (92% rr) to quantitative (>99% rr) syndiotacticity. A combined experimental (synthetic, kinetic, and mechanistic) and theoretical (DFT) investigation has yielded a unimetallic, enantiomorphic-site controlled propagation mechanism. Post-functionalization of the obtained syndiotactic vinyl-functionalized polymers via the thiol-ene click and photocuring reactions readily produced the corresponding thiolated polymers and flexible crosslinked thin film materials, respectively. Complexation of such syndiotactic vinyl-functionalized polymers with isotactic poly(methyl methacrylate) and fullerene C60 generates supramolecular crystalline helical stereocomplexes and inclusion complexes, respectively. Crosslinking of such complexes afforded robust crosslinked stereocomplexes that are solvent resistant and also exhibit considerably enhanced thermal and mechanical properties as compared to the uncrosslinked stereocompexes.

Synthesis and photostabilizing performance of a polymeric HALS based on 1,2,2,6,6-pentamethylpiperidine and vinyl acetate

Directory of Open Access Journals (Sweden)

Marcelo Aparecido Chinelatto

2015-01-01

Full Text Available Abstract Polymeric hindered amine light stabilizers (polymeric HALS have been extensively studied because they combine a high ability to protect the polymers against harmful effects of weathering with minimum physical loss. In this study a new polymeric N-methylated HALS was synthesized by the radical copolymerization of a cyclic tertiary amine with vinyl acetate (VAc. 4-Acryloyloxy-1,2,2,6,6-pentamethylpiperidine (APP, the cyclic tertiary amine, was prepared by the initial conversion of 2,2,6,6-tetramethyl-4-piperidinol derivatives via two different routes. The APP/VAc copolymer synthesized was characterized by size exclusion chromatography (SEC, Fourier transform infrared spectroscopy (FTIR and carbon-13 nuclear magnetic resonance (13C NMR. The photostabilizing performance, particularly the induction period of polypropylene (PP films containing different concentrations of APP/VAc copolymer, when exposed to accelerated aging, was comparable to that of PP films compounded with commercial polymeric HALS.

Influence of substituents in vinyl groups on reactivity of parylene during polymerization process

International Nuclear Information System (INIS)

Freza, Sylwia; Skurski, Piotr; Bobrowski, Maciej

2010-01-01

The MCSCF calculations indicate that both triplet and singlet state of biradical di-para-xylylene can exist during polymerization of parylene in gas phase and both can potentially react with vinyl molecules. The singlet-state open-shell dimer turned out to exhibit multiconfigurational character. In the case of triplet state of the dimer two mechanisms of the reactions with various species containing vinyl groups have been examined at the B3LYP/6-31G level. The kinetic and thermodynamical barriers have been estimated for the reaction path involving the π-bond cleavage as well as for the route describing the hydrogen atom transfer. It was found that the overall reactions are thermodynamically favorable, whereas appropriate kinetic barriers for certain derivatives are very small (close to 0 kcal/mol) which in turn makes allowances for easy reactivity under accessible conditions. The calculated mechanisms indicate the influence of substituents in vinyl groups for reactivity of parylene during LPCVD process.

Gamma radiolysis and vinyl esters

International Nuclear Information System (INIS)

De Bruyn, H.; Balic, R.; Gilbert, R.G.

1998-01-01

The principle behind γ relaxation of free-radical polymerizations is that the source of initiating radicals can be switched off 'instantaneously'. In the absence of initiating radicals the only kinetic events remaining are propagation, transfer and termination. For monomers whose propagation rate coefficients have been determined, relaxation behaviour can be interpreted to determine radical-loss rate coefficients and test models of loss mechanisms. This technique has been employed successfully on styrene and MMA emulsion polymerizations. In the present study, vinyl acetate and vinyl neo-decanoate (a ten-carbon-branched homologue of vinyl acetate) were studied, with the propagation rate coefficients for both monomers being established by pulsed-laser polymerization. Both were found to exhibit rapid γ relaxation rates in emulsion polymerization. This is a surprising result because mechanisms for rapid relaxation in emulsion polymerizations require that chain transfer to monomer (which is rapid for both monomers) is followed by exit from the particle into the aqueous phase with subsequent re-entry into a radical-containing particle leading to bimolecular termination. It is not unreasonable to suppose that this may be possible for vinyl acetate which is fairly water soluble (∼0.3 M). However, vinyl neo-decanoate is virtually insoluble (∼0.00004 M) and hence desorption is extremely unlikely. The most likely explanation for the observed rapid relaxations is that some of the radicals produced by γ radiolysis are slow to initiate vinyl esters and hence act as radical traps. As vinyl esters are known to be particularly unreactive monomers. it is feasible that this experimental artifact affects them to a much greater extent than some of the monomers studied successfully with this technique in the past

Zirconium and Titanium Propylene Polymerization Precatalysts Supported by a Fluxional C 2 -Symmetric Bis(anilide)pyridine Ligand

KAUST Repository

Tonks, Ian A.

2012-03-12

Titanium and zirconium complexes supported by a bis(anilide)pyridine ligand (NNN = pyridine-2,6-bis(N-mesitylanilide)) have been synthesized and crystallographically characterized. C 2-symmetric bis(dimethylamide) complexes were generated from aminolysis of M(NMe 2) 4 with the neutral, diprotonated NNN ligand or by salt metathesis of the dipotassium salt of NNN with M(NMe 2) 2Cl 2. In contrast to the case for previously reported pyridine bis(phenoxide) complexes, the ligand geometry of these complexes appears to be dictated by chelate ring strain rather than metal-ligand π bonding. The crystal structures of the five-coordinate dihalide complexes (NNN)MCl 2 (M = Ti, Zr) display a C 1-symmetric geometry with a stabilizing ipso interaction between the metal and the anilido ligand. Coordination of THF to (NNN)ZrCl 2 generates a six-coordinate C 2-symmetric complex. Facile antipode interconversion of the C 2 complexes, possibly via flat C 2v intermediates, has been investigated by variable-temperature 1H NMR spectroscopy for (NNN)MX 2(THF) n (M = Ti, Zr; X = NMe 2, Cl) and (NNN)Zr(CH 2Ph) 2. These complexes were tested as propylene polymerization precatalysts, with most complexes giving low to moderate activities (10 2-10 4 g/(mol h)) for the formation of stereoirregular polypropylene. © 2012 American Chemical Society.

Radiation-induced cationic curing of vinyl ethers

International Nuclear Information System (INIS)

Lapin, S.C.

1992-01-01

Recently there has been an increasing interest in nonacrylate radiation-curable coatings. Vinyl ethers are particularly reactive under cationic polymerization reaction conditions. The high efficiency of the photoacid initiators combined with the high reactivity of vinyl ether monomers makes this a potentially very useful system. This chapter discusses the preparation of vinyl ethers, introduces vinyl ether-functional monomers and oligomers, describes radiation-induced cationic polymerization of vinyl ethers, and discusses various coating systems. Throughout the chapter, an emphasis is placed on radiation-curable coating applications. 64 refs., 5 figs., 11 tabs

Polymerization of vinyl stearate multilayers by electron beam irradiation

International Nuclear Information System (INIS)

Nishii, Masanobu; Hatada, Motoyoshi

1975-01-01

Studies on the radiation-induced polymerization of vinyl stearate (VST) multilayers were carried out. The VST multilayers built-up on an aluminum plated glass plate by Langmuir-Blodgett technique were irradiated with electron beams from a Van de Graaff electron accelerator in nitrogen atmosphere. The structure of the multilayers and the effects of irradiation were investigated by X-ray diffractometry, contact angle measurement, multireflection infrared spectroscopy, and scanning electron microscopy. The VST multilayers became insoluble to methanol by the irradiation, and the multi-reflection infrared spectrum of the VST multilayers turned into that of poly (VST) with increasing dosage. The polymerization proceeded during the irradiation at the temperature range between -10 0 and 10 0 C, and the conversion attained to 90% within 2.5 minutes (total dose, 5.6 Mrads). The multilayers irradiated above 13 Mrads turned into the polymer film insoluble to benzene, indicating that the polymer chains were cross-linked by the irradiation. Stearic acid which was formed by the irradiation of VST at nitrogen-water interface as a hydrolysis product was not detected in this system. (auth.)

Preparation and characterization of a magneto-polymeric nanocomposite: Fe 3O 4 nanoparticles in a grafted, cross-linked and plasticized poly(vinyl chloride) matrix

Science.gov (United States)

Rodríguez-Fernández, Oliverio S.; Rodríguez-Calzadíaz, C. A.; Yáñez-Flores, Isaura G.; Montemayor, Sagrario M.

In this work two kind of materials: (1) grafted, cross-linked and plasticized poly(vinyl chloride) (PVC) "plastic films" and (2) magnetic plastic films "magneto-polymeric nanocomposites" were prepared. Precursor solutions or "plastisols" used to obtain the plastic films were obtained by mixing PVC (emulsion grade) as polymeric matrix, di(2-ethylhexyl)phthalate (DOP) as plasticizer, a thermal stabilizer based in Ca/Zn salts, and a cross-linking agent, 3-mercaptopropyltrimethoxysilane (MTMS) or 3-aminopropyltriethoxysilane (ATES), at several concentrations. Flexible films were obtained from the plastisols using static casting. The stress-strain behavior and the gel content (determined by Soxhlet extraction with boiling THF) of the flexible films were measured in order to evaluate the effect of the cross-linking agent and their content on the degree of cross-linking. The magneto-polymeric nanocomposites were obtained by mixing the optimum composition of the plastisols (analyzed previously) with magnetite (Fe 3O 4)-based ferrofluid and DOP. Later, flexible films were obtained by static casting of the plastisol/ferrofluid systems. The magnetic films were characterized by the above-mentioned techniques and X-ray diffraction, vibrating sample magnetometry and thermogravimetrical analysis.

Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers

International Nuclear Information System (INIS)

Heinze, D.; Mang, Th.; Popescu, C.; Weichold, O.

2016-01-01

Highlights: • Thermal behaviour of telomerized polyvinyl esters is investigated. • Thermal stability relies mainly on the contribution of side chains. • At equal molecular weights thermal stability is dictated by length of side chain. • Increasing the length of side chains improves also the packing degree of polymer. - Abstract: Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl_3–(CH_2CH (OCO(CH_2)_mCH_3))_n–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.

Effect of side chain length and degree of polymerization on the decomposition and crystallization behaviour of chlorinated poly(vinyl ester) oligomers

Energy Technology Data Exchange (ETDEWEB)

Heinze, D.; Mang, Th. [Aachen University of Applied Sciences, Heinrich-Mussmann-Str. 1, 52428 Jülich (Germany); Popescu, C., E-mail: crisan.popescu@kao.com [KAO Germany GmbH, Pfungstädterstr. 98-100, 64297 Darmstadt (Germany); Weichold, O., E-mail: weichold@ibac.rwth-aachen.de [Institute of Building Materials Research, Schinkelstr. 3, 52062 Aachen (Germany)

2016-08-10

Highlights: • Thermal behaviour of telomerized polyvinyl esters is investigated. • Thermal stability relies mainly on the contribution of side chains. • At equal molecular weights thermal stability is dictated by length of side chain. • Increasing the length of side chains improves also the packing degree of polymer. - Abstract: Four members of a homologous series of chlorinated poly(vinyl ester) oligomers CCl{sub 3}–(CH{sub 2}CH (OCO(CH{sub 2}){sub m}CH{sub 3})){sub n}–Cl with degrees of polymerization of 10 and 20 were prepared by telomerisation using carbon tetrachloride. The number of side chain carbon atoms ranges from 2 (poly(vinyl acetate) to 18 (poly(vinyl stearate)). The effect of the n-alkyl side chain length and of the degree of polymerization on the thermal stability and crystallization behaviour of the synthesized compounds was investigated. All oligomers degrade in two major steps by first losing HCl and side chains with subsequent breakdown of the backbone. The members with short side chains, up to poly(vinyl octanoate), are amorphous and show internal plasticization, whereas those with high number of side chain carbon atoms are semi-crystalline due to side-chain crystallization. A better packing for poly(vinyl stearate) is also noticeable. The glass transition and melting temperatures as well as the onset temperature of decomposition are influenced to a larger extent by the side chain length than by the degree of polymerization. Thermal stability is improved if both the size and number of side chains increase, but only a long side chain causes a significant increase of the resistance to degradation. This results in a stabilization of PVAc so that oligomers from poly(vinyl octanoate) on are stable under atmospheric conditions. Thus, the way to design stable, chlorinated PVEs oligomers is to use a long n-alkyl side chain.

Preparation of Macroporous Poly (vinyl alcohol-co-triallyl isocyanurate) Beads Bearing Aminocarboxylic Acid as Functional Groups by Suspension Polymerization

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by ester exchange reaction. Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride. The weak acid exchange capacities, specific surface areas and mean pore diameters of the resultant resin beads were measured.

On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

Energy Technology Data Exchange (ETDEWEB)

Navarrete-Encina, Patricio A.; Vega-Retter, Christian, E-mail: pnavarre@vtr.ne [Universidad de Chile, Santiago (Chile). Facultad de Ciencias Quimicas y Farmaceuticas. Lab. de Sintesis Organica y Fisicoquimica; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J. [Universidad de Chile, Santiago (Chile). Fac. de Ciencias Quimicas y Farmaceuticas. Lab. de Bioelectroquimica

2010-07-01

Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

International Nuclear Information System (INIS)

Navarrete-Encina, Patricio A.; Vega-Retter, Christian; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J.

2010-01-01

Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

UV-VIS-spectroscopical investigations of the green solutions of nitrogen triiodide-1-pyridine in pyridine

International Nuclear Information System (INIS)

Kerbachi, R.; Minkwitz, R.; Engelhardt, U.

1984-01-01

Solid, crystalline nitrogen triiodide-1-pyridine has a polymeric structure similar to that of nitrogen triiodide-1-ammonia consisting of NI 4 tetrahedra linked to chains by common vertices. The solubility of both compounds in liquid ammonia is accomplished by a degradation of the chains involving protolysis equilibria with monoiodamine. UV-VIS-spectra of the green solutions of NI 3 pyridine in the aprotic solvent pyridine between -30 and -16 0 C and Raman-spectra of these solutions at -30 0 C or quenched with liquid nitrogen at -196 0 C show, that the chains are retained here at least to some extent. The solutions are instable even at low temperatures and decompose in a first order reaction yielding nitrogen and iodine. The halflife period at -16 0 C is 5 hours, at -30 0 C 20 hours. (author)

2-Amino­benzoic acid–4-[2-(pyridin-4-yl)eth­yl]pyridine (2/1)

OpenAIRE

Arman, Hadi D.; Tiekink, Edward R. T.

2013-01-01

The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-yl)ethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6)°] despite the presence of an intramolecular N—H...O(carbonyl) hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl) hydrogen bonds, and these are connecte...

Kinetics of waterborne fluoropolymers prepared by one-step semi-continuous emulsion polymerization of chlorotrifluoroethylene, vinyl acetate, butyl acrylate and Veova 10

Science.gov (United States)

Liu, H. Z.; Wang, M. H.; Wang, Z. F.; Bian, J. M.

2018-01-01

Due to using gaseous fluorine monomer with toxicity, waterborne fluoropolymers are synthesized by semi-continuous high-pressure emulsion polymerization method which differs from free-pressure emulsion polymerization. To dates, the research on preparing process and kinetics for high-pressure emulsion polymerization is reported relatively less, which hinders researchers from understanding of mechanisms for monomer-fluorinated emulsion polymerization. The paper also provides a new method by element auxiliary analysis to calculate kinetics parameters of high-pressure emulsion polymerization. Based on aforementioned consideration, waterborne fluoropolymers were prepared by copolymerization of chlorotrifluoroethylene (CTFE), vinyl acetate (VAc), butyl acrylate (BA) and vinyl ester of versatic acid (Veova 10) using potassium persulfate as initiator and mixed surfactants. The kinetics of emulsion polymerization of waterborne fluoropolymers was then investigated. Effects of emulsifier concentration, initiator concentration, and polymerization temperature on polymerization rate (Rp) were evaluated, and relationship was described as Rp∝[I]0.10 and Rp∝[E]0.12. The apparent activation energy was determined to be 33.61 kJ·mol-1. Moreover, the relative conversion rate of CTFE with the other monomers was observed, and results indicated that CTFE monomer more uniformly copolymerized with the other monomers. The resulting emulsion properties and pressure change in an autoclave were evaluated at different stirring rates. The initial reaction time, defined as the beginning time of dropwise addition, was determined by the change in solid content and particle size of emulsion.

Amphiphilic Fluorinated Block Copolymer Synthesized by RAFT Polymerization for Graphene Dispersions

Directory of Open Access Journals (Sweden)

Hyang Moo Lee

2016-03-01

Full Text Available Despite the superior properties of graphene, the strong π–π interactions among pristine graphenes yielding massive aggregation impede industrial applications. For non-covalent functionalization of highly-ordered pyrolytic graphite (HOPG, poly(2,2,2-trifluoroethyl methacrylate-block-poly(4-vinyl pyridine (PTFEMA-b-PVP block copolymers were prepared by reversible addition-fragmentation chain transfer (RAFT polymerization and used as polymeric dispersants in liquid phase exfoliation assisted by ultrasonication. The HOPG graphene concentrations were found to be 0.260–0.385 mg/mL in methanolic graphene dispersions stabilized with 10 wt % (relative to HOPG PTFEMA-b-PVP block copolymers after one week. Raman and atomic force microscopy (AFM analyses revealed that HOPG could not be completely exfoliated during the sonication. However, on-line turbidity results confirmed that the dispersion stability of HOPG in the presence of the block copolymer lasted for one week and that longer PTFEMA and PVP blocks led to better graphene dispersibility. Force–distance (F–d analyses of AFM showed that PVP block is a good graphene-philic block while PTFEMA is methanol-philic.

Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

KAUST Repository

Gong, Dirong; Jia, Xiaoyu; Wang, Baolin; Zhang, Xuequan; Huang, Kuo-Wei

2014-01-01

Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

KAUST Repository

Gong, Dirong

2014-09-01

Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

Complex Macromolecular Architectures by Living Cationic Polymerization

KAUST Repository

Alghamdi, Reem D.

2015-05-01

Poly (vinyl ether)-based graft polymers have been synthesized by the combination of living cationic polymerization of vinyl ethers with other living or controlled/ living polymerization techniques (anionic and ATRP). The process involves the synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy) ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic polymerizations of those monomers were conducted in hexane at -20 0C using Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base.[1] The PCEVE segments of the synthesized block terpolymers were then used to react with living macroanions (PS-DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The quantitative desilylation of PSiDEGVE segments by n-Bu4N+F- in THF at 0 °C led to graft co- and terpolymers in which the polyalcohol is the outer block. These co-/terpolymers were subsequently subjected to “grafting-from” reactions by atom transfer radical polymerization (ATRP) of styrene to afford more complex macromolecular architectures. The base assisted living cationic polymerization of vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether (PnBVE-OH). The resulting polymers were then modified into an ATRP macro-initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS). Bifunctional PnBVE with terminal malonate groups was also synthesized and used as a precursor for more complex architectures such as H-shaped block copolymer by “grafting-from” or �

Uranium Adsorbent Fibers Prepared by Atom-Transfer Radical Polymerization (ATRP) from Poly(vinyl chloride)- co -chlorinated Poly(vinyl chloride) (PVC- co -CPVC) Fiber

Energy Technology Data Exchange (ETDEWEB)

Brown, Suree; Yue, Yanfeng; Kuo, Li-Jung; Mehio, Nada; Li, Meijun; Gill, Gary; Tsouris, Costas; Mayes, Richard T.; Saito, Tomonori; Dai, Sheng

2016-04-20

The need to secure future supplies of energy attracts researchers in several countries to a vast resource of nuclear energy fuel: uranium in seawater (estimated at 4.5 billion tons in seawater). In this study, we developed effective adsorbent fibers for the recovery of uranium from seawater via atom-transfer radical polymerization (ATRP) from a poly- (vinyl chloride)-co-chlorinated poly(vinyl chloride) (PVC-co-CPVC) fiber. ATRP was employed in the surface graft polymerization of acrylonitrile (AN) and tert-butyl acrylate (tBA), precursors for uranium-interacting functional groups, from PVC-co-CPVC fiber. The [tBA]/[AN] was systematically varied to identify the optimal ratio between hydrophilic groups (from tBA) and uranyl-binding ligands (from AN). The best performing adsorbent fiber, the one with the optimal [tBA]/[AN] ratio and a high degree of grafting (1390%), demonstrated uranium adsorption capacities that are significantly greater than those of the Japan Atomic Energy Agency (JAEA) reference fiber in natural seawater tests (2.42-3.24 g/kg in 42 days of seawater exposure and 5.22 g/kg in 49 days of seawater exposure, versus 1.66 g/kg in 42 days of seawater exposure and 1.71 g/kg in 49 days of seawater exposure for JAEA). Adsorption of other metal ions from seawater and their corresponding kinetics were also studied. The grafting of alternative monomers for the recovery of uranium from seawater is now under development by this versatile technique of ATRP.

Radiation fixation of vinyl chloride in an insecticide aerosol container

International Nuclear Information System (INIS)

Kagiya, V.T.; Takemoto, K.

1975-01-01

Recently, a large quantity of vinyl chloride has been used as spraying additive for insecticide aerosols. Since January 1974 when the Food and Drug Administration of the United States of America announced that vinyl chloride causes liver cancer, it has been forbidden in Japan and the United States of America to market insecticide aerosol containers containing vinyl chloride. In Japan, following a government order, about 20 million insecticide aerosol containers have been collected and put into storage. A report is given on the radiation fixation of vinyl chloride as polyvinylchloride powder by gamma-ray-induced polymerization in the aerosol container. Insecticide aerosol containers containing vinyl chloride were irradiated by gamma rays from 60 Co at room temperature. Vinyl chloride polymerized to form powdered polymer in the container. Polymerization conversion increased with the irradiation dose, and after 10 Mrad irradiation, vinyl chloride was not found in the sprayed gas. This establishes that vinyl chloride can be fixed by gamma-ray irradiation in the aerosol container. To accelerate the reaction rate, the effect of various additives on the reaction was investigated. It was found that halogenated hydrocarbons, such as chloroform and carbon tetrachloride, accelerated the initiation of the polymerization, and that a vinyl monomer such as vinyl acetate accelerated the reaction rate due to the promotion of the initiation and the high reactivity of the polyvinylacetate radical to vinyl chloride. Consequently, the required irradiation dose for the fixation of vinyl chloride was decreased to less than 5 Mrad by the addition of various kinds of additives. Following the request of the Ministry of Public Welfare, various technical problems for large-scale treatment are being studied with the co-operation of the Federation of Insecticide Aerosols. (author)

Synthesis and biological evaluation of cis-locked vinylogous combretastatin-A4 analogues: derivatives with a cyclopropyl-vinyl or a cyclopropyl-amide bridge.

Science.gov (United States)

Ty, Nancy; Kaffy, Julia; Arrault, Alban; Thoret, Sylviane; Pontikis, Renée; Dubois, Joelle; Morin-Allory, Luc; Florent, Jean-Claude

2009-03-01

A series of novel combretastatin A4 analogues, in which the cis-olefinic bridge is replaced by a cyclopropyl-vinyl or a cyclopropyl-amide moiety, were synthesized and evaluated for inhibition of tubulin polymerization and antiproliferative activity. The derivative 9a with a (cis,E)-cyclopropyl-vinyl unit is the most promising compound. As expected, molecular docking of 9a has shown that only one of the cis-cyclopropyl enantiomers is a good ligand for tubulin.

2-Aminobenzoic acid–4-(pyridin-4-yldisulfanylpyridine (1/1

Directory of Open Access Journals (Sweden)

Hadi D. Arman

2011-12-01

Full Text Available The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanylpyridine molecule [dihedral angle between the pyridine rings = 89.06 (10°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O—H...N and N—H...N hydrogen bonds into a supramolecular chain along the b axis. These are connected into layers by π–π interactions occurring between pyridine rings [centroid–centroid distance = 3.8489 (15 Å]. The layers are connected along the a axis by C—H...O contacts. The crystal studied was a racemic twin.

Kinetics of vinyl acetate emulsion polymerization in a pulsed tubular reactor: comparison between experimental and simulation results

Directory of Open Access Journals (Sweden)

Sayer C.

2002-01-01

Full Text Available A new reactor, the pulsed sieve plate column (PSPC, was developed to perform continuous emulsion polymerization reactions. This reactor combines the enhanced flexibility of tubular reactors with the mixing behavior provided by sieved plates and by the introduction of pulses that is important to prevent emulsion destabilization. The main objective of this work is to study the kinetics of vinyl acetate (VA emulsion polymerization reactions performed in this PSPC. Therefore, both experimental studies and reaction simulations were performed. Results showed that it is possible to obtain high conversions with rather low residence times in the PSPC.

Improving the Performances of Poly(vinylphosphonic acid) by Compositing or Copolymerization with Poly(4-(α-methyl)vinyl-1H-1,2,3-triazole)

International Nuclear Information System (INIS)

Han, Shuaiyuan; Yue, Baohua; Yan, Liuming

2014-01-01

Graphical abstract: - Highlights: • Poly(4-(α-methyl)vinyl-1H-1,2,3-triazole) is synthesized • PVPA/PMVTri polymeric composite proton conducting membranes are prepared • The proton conductivity of PVPA is improved by compositing with PMVTri • The water resistance of PVPA is improved by compositing with PMVTri • The oxidative stability is greatly improved - Abstract: The poly(vinylphosphonic acid) (PVPA), poly(4-(α-methyl)vinyl-1H-1,2,3-triazole) (PMVTri), and poly(VPA-co-MVTri) were synthesized, and proton exchange membranes were prepared based on the acid-base polymeric composite of PVPA and PMVTri, and acid-base amphoteric copolymer of poly(VPA-co-MVTri). The overall performances of PVPA, proton conductivity, thermal and oxidative stability, and water resistance, are greatly improved by compositing of PMVTri or copolymerization with 4-(α-methyl)vinyl-1H-1,2,3-triazole (MVTri). About four or eight folds improvement in maximum proton conductivity was observed in the polymeric composite of PVPA/PMVTri or acid-base amphoteric copolymer poly(VPA-co-MVTri) because of the redistribution of ions in the heterostructures of PVPA and PMVTri, respectively, compared with the pristine PVPA. At the same time, the oxidative stability and the water resistance of PVPA were also greatly improved attributing to the absent of α-H in the main chain of PMVTri and the acid-base interaction between the phosphonic acid groups and the triazolyl groups, respectively

Graft copolymers of polyurethane with various vinyl monomers via radiation-induced miniemulsion polymerization: Influential factors to grafting efficiency and particle morphology

Energy Technology Data Exchange (ETDEWEB)

Wang Hua [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China); Wang Mozhen [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: pstwmz@ustc.edu.cn; Ge Xuewu [CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China (USTC), Hefei, Anhui 230026 (China)], E-mail: xwge@ustc.edu.cn

2009-02-15

Graft copolymers of polyurethane (PU) with various vinyl monomers were synthesized through a one-pot but two-step miniemulsion polymerization process. Firstly, the polycondensation of isophorone diisocyanate (IPDI) with hydroxyl-terminated polybutadiene (HTPB) had been performed in aqueous miniemulsion at 40 deg. C in order to obtain PU dispersions. Consecutively, an in-situ graft copolymerization of the vinyl monomers with the synthesized PU was initiated by {gamma}-ray radiation at room temperature. The grafting efficiency of PU with vinyl monomer (G{sub PU/monomer}) was calculated from {sup 1}H NMR spectra and the particle morphology of the final hybrid latex was observed by transmission electron microscopy (TEM). As there was no monomer transferring in miniemulsion system, homogenous hybrid particles would be synthesized provided that the monomer was miscible with PU, such as styrene. With the increase of the polarity of the monomer, the compatibility of PU with monomer decreased. G{sub PU/monomer} varied as G{sub PU/styrene}(37%)>G{sub PU/butyl} {sub acrylate} {sub (BA)}(21%)>G{sub PU/methyl} {sub methacrylate} {sub (MMA)}(12%). The proportion of homogeneous nucleation would increase as the hydrophilicity of the monomer increased. High temperature would destabilize the miniemulsion so as to result in a less grafting efficiency. Compared to the phase separation during the seeded emulsion polymerization, the miniemulsion polymerization method facilitated the preparation of homogeneous materials owing to its monomer droplet nucleation mechanism.

Plasma-polymerized alkaline anion-exchange membrane: Synthesis and structure characterization

International Nuclear Information System (INIS)

Hu Jue; Meng Yuedong; Zhang Chengxu; Fang Shidong

2011-01-01

After-glow discharge plasma polymerization was developed for alkaline anion-exchange membranes synthesis using vinylbenzyl chloride as monomer. X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy were used to characterize the chemical structure properties of plasma-polymerized membranes. Ion-exchange capacities of quaternized poly(vinylbenzyl chloride) (QPVBC) membranes were measured to evaluate their capability of hydroxyl ion transport. A mechanism of plasma polymerization using VBC as monomer that accounts for the competitive effects of free radicals polymerization and plasma ablation in the plasma polymerization process was proposed. Our results indicate that plasma discharge power influences the contents of functional groups and the structure of the plasma polymer membranes, which attribute to the coactions of polymerization and ablation. The properties of uniform morphology, good adhesion to the substrate, high thermal stability and satisfying anion conduction level suggest the potential application of QPVBC membrane deposited at discharge power of 20 W in alkaline direct methanol fuel cells.

Synthesis of 1-Substituted-4-(Pyridin-4-yl)

African Journals Online (AJOL)

Purpose: To synthesize a new series of 1-substituted-4-(pyridin-4-yl) [1,2,4] triazolo [4,3-a]quinazolin- 5(4H)-ones and evaluate them for H1-antihistaminic activity with negligible side effects in guinea pigs. Methods: The synthesized compounds were characterized by Infrared spectroscopy (IR), proton nuclear magnetic ...

Fine structures and magnetic properties of FeCo granular thin films with plasma polymerized (C4F8) n matrix

International Nuclear Information System (INIS)

Kakizaki, K.; Yasoshima, S.; Choi, K.-K.; Kamishima, K.; Hiratsuka, N.

2007-01-01

In this paper a method for polymerization of fluorocarbon gas in argon plasma to obtain a novel granular structure was reported. We prepared granular films where FeCo fine particles were distributed in plasma-polymerized fluorocarbon matrix by a facing-targets RF magnetron sputtering method, and investigated the correlation between their structures and magnetic properties. The magnetization of the films prepared with the partial pressure of fluorocarbon gas between 0 and 1.0 mTorr decreased linearly, because the FeCo content in a unit volume of a film decreased when a polymerized material was used as the matrix. However, the coercivity of the films decreased drastically with increasing the partial pressure of fluorocarbon gas above 0.4 mTorr. This is because the magnetic anisotropy of FeCo particles is decreased by the decrease of grain size. It was confirmed by a TEM observation that the FeCo-(C 4 F 8 ) n films had the granular structure which was constituted by the very fine FeCo particles and the plasma-polymerized fluorocarbon matrix. For the film deposited at the partial pressure of fluorocarbon gas of 0.4 mTorr, the size of FeCo magnetic particles is about 20 nm. On the other hand, the size of FeCo particles is decreased to about 8 nm when the film deposited at the partial pressure of fluorocarbon gas of 0.8 mTorr and its distribution is small

Poly(vinyl acetate-Based Block Copolymer/Clay Nanocomposites Prepared by In Situ Atom Transfer Radical Polymerization

Directory of Open Access Journals (Sweden)

M.A. Semsarzadeh

2009-12-01

Full Text Available Atom transfer radical polymerization of styrene (St and methyl methacrylate (MMA was performed at 90oC in the absence and presence of nanoclay (Cloisite 30B. Trichloromethyl-terminated poly(vinyl acetate telomerand CuCl/ PMDETA were used as a macroinitiator and catalyst system, respectively. The experimental results showed that the atom transfer radical polymerization of St and MMA in the absence or presence of nanoclay proceeds via a controlled/living mode. It was observed that nanoclay significantly enhances the homopolymerization rate of MMA, which was attributed to the activated conjugated C=C bond of MMA monomer via interaction between the carbonyl group of MMA monomer and the hydroxyl moiety (Al-O-H of nanoclay as well as the effect of nanoclay on the dynamic equilibrium between the active (macro radicals and dormant species.Homopolymerization rate of St (a non-coordinative monomer with nanoclay decreased slightly in the presence of nanoclay. This could be explained by insertion of a portion of macroinitiator into the clay galleries, where no sufficient St monomer exists due to the low compatibility or interaction of St monomer with nanoclay to react with the macroinitiator. The results obtained from XRD, TEM and TGA analyses were fully in agreement with the kinetic data. Structure of the poly(vinyl acetate-bpolystyrene nanocomposite was found to be a combination of stacking layers and exfoliated structures while poly(vinyl acetate-b-poly(methyl methacryale nanocomposite had an exfoliated structure. This difference in the structure of nanocomposites was attributed to the different capability of the monomers (styrene and methyl methacrylate to react with the hydroxyl moiety (Al-O-H of nanoclay.

The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl) Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

International Nuclear Information System (INIS)

Shaffei, K.A.; Moustafa, A.B.; Hamed, A.I.

2009-01-01

Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of poly butyl acrylate were achieved by using bis (2-ethylhexyl) maleate (BEHM). The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

Directory of Open Access Journals (Sweden)

K. A. Shaffei

2009-01-01

Full Text Available Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of polybutyl acrylate were achieved by using bis (2-ethylhexyl maleate (BEHM. The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

13C n.m.r. study of solvation mechanisms in the radiation-induced polymerization of vinyl ethers

International Nuclear Information System (INIS)

Deffieux, A.; Subira, F.; Stannett, V.T.

1984-01-01

A 13 C n.m.r. study of the microstructure of ethyl vinyl ether (EVE) and isopropyl vinyl ether (IPVE) polymers prepared under various experimental conditions and using chemical or γ-ray initiation has been made. Long stereo-sequence assignments were conducted for poly EVE allowing determination of the configurational statistics of propagation in the radiation-induced polymerization of EVE in low polar solvents. Stereo-sequence intensities are found in good agreement with the Markovian model. The results are considered as further support for the occurrence of a specific interaction between the growing active centres and the polymer chains. In the case of IPVE polymers much more important overlappings of the resonance patterns are observed thus preventing any similar detailed study. (author)

Comparative pharmacokinetic study of dosage forms with morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate

Directory of Open Access Journals (Sweden)

I. V. Bushueva

2014-12-01

] acetate elimination from the body of the animal occurs within 1 hour, and then only trace amount of the drug substanceis detected in serum. After oral and rectal dosage forms of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate its maximum concentration in the blood of laboratory animals is recorded at 60 minutes after administration of the capsules and suppositories respectively. Thereafter, for 2-2, 5 it is supported at a high level. At the same time, no significant differences in the kinetics of the drug administered dose. 24 hours after single oral administration and rectal capsules and suppositories of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate is not detected in the serum. Comparative analysis of the pharmacokinetics of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate depending on the kind of administration and the dosage form shows that after oral administration in capsule form, and rectal administration as a suppository absorption rate constants, elimination, half-life periods floor suction and depending on the dose administered differ slightly. Also, almost no relationship between dose and orally administered rectally morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate and total quantities (of plasma clearance, since the difference between the drug administered in doses of 5 times the value of the latter increased only 1.2 times. Degree of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate absolute bioavailability after oral and rectal administration, is practically independent from the dose. The magnitude of this indicator for rectal suppository almost 3 times higher than that for oral capsules of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate. This indicates the great promise of his rectal dosage form. Conclusion. The degree of its absolute bioavailability for rectal dosage form doesn’t depend on administered dose and is nearly twice higher than for the oral solid

Wetting, Solubility and Chemical Characteristics of Plasma-Polymerized 1-Isopropyl-4-Methyl-1,4-Cyclohexadiene Thin Films

Directory of Open Access Journals (Sweden)

Jakaria Ahmad

2014-07-01

Full Text Available Investigations on the wetting, solubility and chemical composition of plasma polymer thin films provide an insight into the feasibility of implementing these polymeric materials in organic electronics, particularly where wet solution processing is involved. In this study, thin films were prepared from 1-isopropyl-4-methyl-1,4-cyclohexadiene (γ-Terpinene using radio frequency (RF plasma polymerization. FTIR showed the polymers to be structurally dissimilar to the original monomer and highly cross-linked, where the loss of original functional groups and the degree of cross-linking increased with deposition power. The polymer surfaces were hydrocarbon-rich, with oxygen present in the form of O–H and C=O functional groups. The oxygen content decreased with deposition power, with films becoming more hydrophobic and, thus, less wettable. The advancing and receding contact angles were investigated, and the water advancing contact angle was found to increase from 63.14° to 73.53° for thin films prepared with an RF power of 10 W to 75 W. The wetting envelopes for the surfaces were constructed to enable the prediction of the surfaces’ wettability for other solvents. The effect of roughness on the wetting behaviour of the films was insignificant. The polymers were determined to resist solubilization in solvents commonly used in the deposition of organic semiconducting layers, including chloroform and chlorobenzene, with higher stability observed in films fabricated at higher RF power.

Evaluation of Osseointegration of Titanium Alloyed Implants Modified by Plasma Polymerization

Directory of Open Access Journals (Sweden)

Carolin Gabler

2014-02-01

Full Text Available By means of plasma polymerization, positively charged, nanometre-thin coatings can be applied to implant surfaces. The aim of the present study was to quantify the adhesion of human bone cells in vitro and to evaluate the bone ongrowth in vivo, on titanium surfaces modified by plasma polymer coatings. Different implant surface configurations were examined: titanium alloy (Ti6Al4V coated with plasma-polymerized allylamine (PPAAm and plasma-polymerized ethylenediamine (PPEDA versus uncoated. Shear stress on human osteoblast-like MG-63 cells was investigated in vitro using a spinning disc device. Furthermore, bone-to-implant contact (BIC was evaluated in vivo. Custom-made conical titanium implants were inserted at the medial tibia of female Sprague-Dawley rats. After a follow-up of six weeks, the BIC was determined by means of histomorphometry. The quantification of cell adhesion showed a significantly higher shear stress for MG-63 cells on PPAAm and PPEDA compared to uncoated Ti6Al4V. Uncoated titanium alloyed implants showed the lowest BIC (40.4%. Implants with PPAAm coating revealed a clear but not significant increase of the BIC (58.5% and implants with PPEDA a significantly increased BIC (63.7%. In conclusion, plasma polymer coatings demonstrate enhanced cell adhesion and bone ongrowth compared to uncoated titanium surfaces.

Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene hydrazono]-thiazolidin-4-one derivatives

Directory of Open Access Journals (Sweden)

Danniel Delmondes Feitoza

2012-01-01

Full Text Available A new series of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC50= 4.25 ± 0.36 µg/mL and 4l (IC50= 1.38 ± 0.04 µg/mL were effective for inhibition of human erythromyeloblastoid leukemia (K-562 and human lung carcinoma (NCI-H292 cell lines, respectively.

Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene) hydrazono]-thiazolidin-4-one derivatives

Energy Technology Data Exchange (ETDEWEB)

Feitoza, Danniel Delmondes; Alves, Antonio Jose; Lima, Jose Gildo de, E-mail: jgildolima@gmail.com [Departamento de Ciencias Farmaceuticas, Universidade Federal de Pernambuco, Recife - PE (Brazil); Araujo, Janete Magali; Aguiar, Jaciana Santos; Rodrigues, Maria do Desterro; Silva, Teresinha Goncalves; Nascimento, Silene Carneiro do; Goes, Alexandre Jose da Silva [Departamento de Antibioticos, Universidade Federal de Pernambuco, Recife - PE (Brazil)

2012-07-01

A new series of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC{sub 50} = 4.25 +- 0.36 {mu}g/mL) and 4l (IC{sub 50} = 1.38 +- 0.04 {mu}g/mL) were effective for inhibition of human erythromyeloblastoid leukemia (K-562) and human lung carcinoma (NCI-H292) cell lines, respectively. (author)

Effect of various solvents on the viscosity-average molecular weight of poly (vinyl acetate)

International Nuclear Information System (INIS)

Rehman, W.U.; But, M.A.; Chughtai, A.; Jamil, T.; Sattar, A.

2006-01-01

Solution polymerization of Vinyl Acetate was carried out in various solvents (benzene, toluene, ethyl acetate, acetonitrile). Dilute solution viscometry was used to determine the viscosity-average molecular weight of the resulting Poly (Vinyl Acetate) (PV Ac) in each case. The viscosity-average molecular weight (M,J of PVAc was found to increase in the order benzene < toluene < ethyl acetate < acetonitrile, It was concluded that under the same reaction conditions (polymerization time, initiator quantity, solvent/monomer ratio, temperature), acetonitrile served as the best solvent for solution. polymerization of Vinyl Acetate monomer. (author)

Self-assembly behavior of poly(fluorenyl styrene)-block-poly(2-vinyl pyridine) and their blends with single wall carbon nanotubes (SWCNT)

Science.gov (United States)

Mezzenga, Raffaele; Li, Chaoxu; Hsu, Jung-Ching; Chen, Wen-Chang; Sugiyama, Kenji; Hirao, Akira

2010-03-01

We describe a supramolecular strategy to disperse carbon nanotubes in block copolymer matrices. To achieve the desired functions and morphologies, comb-type architectures in which one and two fluorene units attached on the styrene ring of polystyrene-block-poly(2-vinyl pyridine) were studied. Depending on the pendant fluorene units, the block ratio, the casting solvent and thermal annealing history, multiple morphologies were found. The phase diagram, compared to PS-b-P2VP, was interpreted in terms of the conformational asymmetry arising from grafting of fluorene units of variable lengths. Hydrogen bonds between COOH-SWCNT and P2VP favor miscibility of SWCNT within P2VP domains and the blending of these two components is reflected both on the final morphologies and on the electron conductivity of the blends.

(Pyridine-2-aldoximato-κ2N,N′bis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III

Directory of Open Access Journals (Sweden)

Bimal Chandra Singh

2013-03-01

Full Text Available In the title complex, [Ir(C11H8N2(C6H5N2O], the octahedrally coordinated IrIII atom is bonded to two 2-(pyridin-2-ylphenyl ligands, through two phenyl C and two pydidine N atoms, and to one pyridine-2-aldoxime ligand through a pyridine N and an oxime N atom. The oxime O atom of the aldoxime unit forms intermolecular C—H...O hydrogen bonds, which result in a two-dimensional hydrogen-bonded polymeric network parallel to (100. C—H...π interactions are also observed.

Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

International Nuclear Information System (INIS)

Yasar-Inceoglu, Ozgul; Mangolini, Lorenzo; Zhong, Lanlan

2015-01-01

Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3–4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented. (paper)

Core/shell silicon/polyaniline particles via in-flight plasma-induced polymerization

Science.gov (United States)

Yasar-Inceoglu, Ozgul; Zhong, Lanlan; Mangolini, Lorenzo

2015-08-01

Although silicon nanoparticles have potential applications in many relevant fields, there is often the need for post-processing steps to tune the property of the nanomaterial and to optimize it for targeted applications. In particular surface modification is generally necessary to both tune dispersibility of the particles in desired solvents to achieve optimal coating conditions, and to interface the particles with other materials to realize functional heterostructures. In this contribution we discuss the realization of core/shell silicon/polymer nanoparticles realized using a plasma-initiated in-flight polymerization process. Silicon particles are produced in a non-thermal plasma reactor using silane as a precursor. After synthesis they are aerodynamically injected into a second plasma reactor into which aniline vapor is introduced. The second plasma initiates the polymerization reactor leading to the formation of a 3-4 nm thick polymer shell surrounding the silicon core. The role of processing conditions on the properties of the polymeric shell is discussed. Preliminary results on the testing of this material as an anode for lithium ion batteries are presented.

Dynamic bioactive stimuli-responsive polymeric surfaces

Science.gov (United States)

Pearson, Heather Marie

This dissertation focuses on the design, synthesis, and development of antimicrobial and anticoagulant surfaces of polyethylene (PE), polypropylene (PP), and poly(tetrafluoroethylene) (PTFE) polymers. Aliphatic polymeric surfaces of PE and PP polymers functionalized using click chemistry reactions by the attachment of --COOH groups via microwave plasma reactions followed by functionalization with alkyne moieties. Azide containing ampicillin (AMP) was synthesized and subsequently clicked into the alkyne prepared PE and PP surfaces. Compared to non-functionalized PP and PE surfaces, the AMP clicked surfaces exhibited substantially enhanced antimicrobial activity against Staphylococcus aureus bacteria. To expand the biocompatibility of polymeric surface anticoagulant attributes, PE and PTFE surfaces were functionalized with pH-responsive poly(2-vinyl pyridine) (P2VP) and poly(acrylic acid) (PAA) polyelectrolyte tethers terminated with NH2 and COOH groups. The goal of these studies was to develop switchable stimuli-responsive polymeric surfaces that interact with biological environments and display simultaneous antimicrobial and anticoagulant properties. Antimicrobial AMP was covalently attached to --COOH terminal ends of protected PAA, while anticoagulant heparin (HEP) was attached to terminal --NH2 groups of P2VP. When pH 5.5, they collapse while the PAA segments extend. Such surfaces, when exposed to Staphylococcus aureus, inhibit bacterial growth due to the presence of AMP, as well as are effective anticoagulants due to the presence of covalently attached HEP. Comparison of these "dynamic" pH responsive surfaces with "static" surfaces terminated with AMP entities show significant enhancement of longevity and surface activity against microbial film formation. The last portion of this dissertation focuses on the covalent attachment of living T1 and Φ11 bacteriophages (phages) on PE and PTFE surface. This was accomplished by carbodiimide coupling between --COOH

Butane-1,4-diyl bis(pyridine-4-carboxylate

Directory of Open Access Journals (Sweden)

J. Muthukumaran

2011-07-01

Full Text Available The molecule of the title compound, C16H16N2O4, lies about an inversion centre; the butane chain adopts an extended zigzag conformation. The dihedral angle between the pyridine ring and the adjacent COO group is 3.52 (s14°.

Variables and advantages of the polymerization process in plasma

International Nuclear Information System (INIS)

Rojas, Andres F; Ortiz, Jairo A; Restrepo, Elizabeth; Devia Alfonso

1998-01-01

They are given to know the parameters that affect the polymerization process in plasma like they are: the kinetics, the electric joining, the variables related to the substrata and the interaction plasma/surface. Some advantages of the polymerization process are also presented with regard to the conventional processes

Radiation-Induced Graft Polymerization of Vinyl Monomers with Anion Groups onto MWNT Supports and Their Application as Electrogenerated Chemiluminescence (ECL Biosensors

Directory of Open Access Journals (Sweden)

Ji-Hye Park

2014-01-01

Full Text Available Vinyl polymer-grafted multiwalled carbon nanotube (MWNT supports with anion groups were prepared for use as biosensor supports by radiation-induced graft polymerization (RIGP of the vinyl monomers acryloyl diphosphoric acid (ADPA, acrylic acid (AA, sodium styrenesulfonate (NaSS, and methacrylic acid (MA onto the surface of MWNTs. The electrogenerated chemiluminescence sensors based on a glass carbon electrode (ECL-GCE and a screen printed electrode (ECL-SPE were fabricated by immobilization of Ru(bpy3 2+ complex after coating of vinyl polymer-grafted MWNT inks on the surface of the GCE and SPE without any polymer binders in order to obtain high electrogenerated chemiluminescence intensity. For detection of alcohol concentration, alcohol dehydrogenase (ADH was immobilized onto an ECL-GCE sensor prepared by poly(NaSS-g-MWNT supports. The prepared biosensor based on ADH is suitable for the detection of ethanol concentration in commercial drinks.

Crystal structures of three co-crystals of 1,2-bis-(pyridin-4-yl)ethane with 4-alk-oxy-benzoic acids: 4-eth-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), 4-n-propoxybenzoic acid-1,2-bis(pyridin-4-yl)ethane (2/1) and 4-n-but-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1).

Science.gov (United States)

Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

2015-11-01

The crystal structures of three hydrogen-bonded co-crystals of 4-alk-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), namely, 2C9H10O3·C12H12N2, (I), 2C10H12O3·C12H12N2, (II), and 2C11H14O3·C12H12N2, (III), have been determined at 93, 290 and 93 K, respectively. In (I), the asymmetric unit consists of one 4-eth-oxy-benzoic acid mol-ecule and one half-mol-ecule of 1,2-bis-(pyridin-4-yl)ethane, which lies on an inversion centre. In (II) and (III), the asymmetric units each comprise two crystallographically independent 4-alk-oxy-benzoic acid mol-ecules and one 1,2-bis-(pyridin-4-yl)ethane mol-ecule. In each crystal, the two components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1unit of the acid and the base. Similar to the structure of 2:1 unit of (I), the units of (II) and (III) adopt nearly pseudo-inversion symmetry. The 2:1 units of (I), (II) and (III) are linked via C-H⋯O hydrogen bonds, forming tape structures.

Fabrication and properties of poly(polyethylene glycol n-alkyl ether vinyl ether)s as polymeric phase change materials

International Nuclear Information System (INIS)

Pei, Dong-fang; Chen, Sai; Li, Shu-qin; Shi, Hai-feng; Li, Wei; Li, Xuan; Zhang, Xing-xiang

2016-01-01

A series of poly(polyethylene glycol n-alkyl ether vinyl ether)s (PC m E n VEs) with various lengths of alkyl chains and polyethylene glycol spacers as side chain (m = 16,18; n = 1,2) were synthesized via two steps. First, monomers-ethylene glycol hexadecyl ether vinyl ether (C 16 E 1 VE), ethylene glycol octadecyl ether vinyl ether (C 18 E 1 VE), diethylene glycol hexadecyl ether vinyl ether (C 16 E 2 VE) and diethylene glycol octadecyl ether vinyl ether (C 18 E 2 VE) were synthesized by a modified Williamson etherification. Then, four new types of phase change materials were successfully fabricated by a living cationic polymerization. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) were employed to characterize their composition, thermal properties and crystallization behavior. The results show that, the side chains of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are in a hexagonal lattice, and the onset temperatures for melting of PC 16 E 1 VE, PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are 39.8 °C, 37.4 °C, 51.0 °C and 48.9 °C, the onset temperatures for crystallization are 36.7 °C, 35.2 °C, 47.4 °C and 46.3 °C, respectively. The enthalpy changes of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 100 J/g; on the contrary, it is 96 J/g for PC 16 E 1 VE. The enthalpy decrease is no more than 11% after 10 heating and cooling cycles. The 5 wt% mass loss temperatures of PC 18 E 1 VE, PC 16 E 2 VE and PC 18 E 2 VE are higher than 300 °C; on the contrary, it’s 283 °C for PC 16 E 1 VE. Using a weak polarity, flexible alkyl ether chain (-OCH 2 CH 2 O-) as a spacer to link the main chain and side chain is conducive to the crystallization of the alkyl side chain. These new phase change materials can be applied in heat storage, energy conservation, and environmental protection.

Characteristics of polyimide-based composite membranes fabricated by low-temperature plasma polymerization

International Nuclear Information System (INIS)

Dung Thi Tran; Mori, Shinsuke; Suzuki, Masaaki

2008-01-01

Composite membranes were prepared by the deposition of plasma-polymerized allylamine films onto a porous polyimide substrate. The relationship between the plasma conditions and the membrane characteristics was described in terms of monomer flow rate, plasma discharge power, plasma polymerization time, and so on. Scanning electron microscope (SEM) images indicate that the thickness of the plasma polymer layer increased and the membrane skin pore size decreased gradually with the increasing of plasma polymerization time. Fourier transform infrared (FTIR) spectra demonstrate the appearance of amine groups in the plasma deposited polymer and the contact angle measurements indicate that the hydrophilicity of the membrane surfaces increased significantly after plasma polymerization. The composite membranes can reject salt from sodium chloride feed solution, and membrane separation performance depends strongly on the plasma conditions applied during the preparation of the plasma deposited polymer films

Radiation-induced polymerization of 1, 3-butadiene in urea canal complex as studied by broad line NMR

International Nuclear Information System (INIS)

Yoshii, Fumio; Hayakawa, Naohiro; Abe, Toshihiko

1975-01-01

Dependence of the NMR spectrum on the molar ratio of 1,3-butadiene to urea, temperature dependence of the spectrum and changes of the spectrum during polymerization were observed. The results were discussed in comparison with previously reported results for the canal polymerization of acrylonitrile and vinyl chloride. 1,3-butadiene formes a canal complex with the molar ratio of 1 to 4 for 1,3-butadiene to urea. The urea canal complex is decomposed at -15 0 C. The spectrum of 1,3-butadiene in urea canal complex shows existence of a remarkably mobile component which was not observed on the spectra of acrylonitrile - urea of vinyl chloride - urea canal complex. The line width of 1,3-butadiene in the urea canal complex except the very narrow component was broader than that for vinyl chloride in the urea canal complex over an observed temperature range. The line width of urea formed the canal decreases at lower temperature than those of urea in vinyl chloride - urea canal complex. The post-polymerization of 1,3-butadiene in the urea canal complex started clearly from -78 0 C and completes when the temperature was raised to 20 0 C. The polymerization will be proceeded by the such way that monomer molecules move to the active center in the canal, as considered in the case of the polymerization of acrylonitrile and vinyl chloride in the canal complex. The crystal structure of the urea canal was maintained during polymerization and than the polybutadiene - urea canal complex was necessarily formed after the polymerization. The formation of the polymer - urea canal complex has distinct difference between 1,3-butadiene and acrylonitrile or vinyl chloride. For acrylonitrile and vinyl chloride the canals around the polymer formed are destroyed. The structure of polybutadiene - urea canal complex was hexagonal having a=8.21, c=10.50 A. (auth.)

PREPARATION AND PROPERTY OF POLYMERIC PENDANT Ru(bpy)32+ COMPLEXES

Institute of Scientific and Technical Information of China (English)

HOU Xiaohuai; Masao Kaneko; Akira Yamada

1984-01-01

Polymeric pendant Ru(bpy)32+ complexes were prepared from homopolymer and copolymers of 4-methyl-4'-vinyl-2,2'-bipyridine (Vbpy). Vbpy was prepared from 4-methylpyridine. The comonomers were styrene (St), acrylic acid (AA), N-vinylpyrrolidone (Pyr), 4-vinylpyridine (Vpy), methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), acrylonitrile (AN) and N-ethyl-4-vinylpyridium bromide (EQ-Vpy). The fraction of the pendant Ru(bpy)32+ repeating unit in the polymeric complex was 0.022 to 0.052. Absorption maximum, molar extinction coefficient, emission maximum and relative emission intensity of the polymeric complexes were studied.

Low-temperature radiation-induced polymerization of vinyl monomers in the crystal matrix of polydimethyl siloxane

International Nuclear Information System (INIS)

Mujdinov, M.R.; Kiryukhin, D.P.; Barkalov, I.M.; Gol'danskij, V.I.

1979-01-01

It is shown that in the process of the slow cooling of vinyl monomer solution in dimethyl siloxane rubber (SKT mark) crystallization of SKT takes place, at that, considerable part of vinyl monomers (up to 70 wt. % of rubber) is sorbed in the pores of crystal matrix and it does not form its proper crystal phase. Slight anomalies in heat capacity in the 120-140 K range, the melting of non-sorbed part of MA and the melting of SKT + MA ''complex'' have been observed on the calorimetric curve at the SKT - methylacrylate (MA) system heating. In the process of heating such samples, irradiated at 77 K by γ-rays of 60 Co, heat evolution connected with sorbed monomer polarization, has been observed starting from 125-130 K. In the 140-200 K range already before MA and SKT melting intense polymerization takes place, which results in practically full monomer consumption and formation of graft copolymer. Radiation-chemical yield of monomer reduction reaches G(-M) approximately equal to 2x10 5 molecules for 100 eV, radiation yield of postpolymerization of crystal MA does not exceed G(-M) approximately equal to 50 molecules for 100 eV

Modulation of release kinetics by plasma polymerization of ampicillin-loaded β -TCP ceramics

International Nuclear Information System (INIS)

Labay, C; Buxadera-Palomero, J; Avilés, M; Canal, C; Ginebra, M P

2016-01-01

Beta-tricalcium phosphate ( β -TCP) bioceramics are employed in bone repair surgery. Their local implantation in bone defects puts them in the limelight as potential materials for local drug delivery. However, obtaining suitable release patterns fitting the required therapeutics is a challenge. Here, plasma polymerization of ampicillin-loaded β -TCP is studied for the design of a novel antibiotic delivery system. Polyethylene glycol-like (PEG-like) coating of β -TCP by low pressure plasma polymerization was performed using diglyme as precursor, and nanometric PEG-like layers were obtained by simple and double plasma polymerization processes. A significant increase in hydrophobicity, and the presence of plasma polymer was visible on the surface by SEM and quantified by XPS. As a main consequence of the plasma polymerisation, the release kinetics were successfully modified, avoiding burst release, and slowing down the initial rate of release leading to a 4.5 h delay in reaching the same antibiotic release percentage, whilst conservation of the activity of the antibiotic was simultaneously maintained. Thus, plasma polymerisation on the surface of bioceramics may be a good strategy to design controlled drug delivery matrices for local bone therapies. (paper)

2-[5-(Pyridin-2-yl-1,3,4-thiadiazol-2-yl]pyridin-1-ium perchlorate

Directory of Open Access Journals (Sweden)

Abdelhakim Laachir

2017-03-01

Full Text Available The cation of the title molecular salt, C12H9N4S+·ClO4−, is approximately planar, with the pyridine and pyridinium rings being inclined to the central thiadiazole ring by 6.51 (9 and 9.13 (9°, respectively. The dihedral angle between the pyridine and pyridinium rings is 12.91 (10°. In the crystal, the cations are linked by N—H...O and C—H...O hydrogen bonds, involving the perchlorate anion, forming chains propagating along the [100] direction. The chains are linked by weak offset π–π interactions [inter-centroid distance = 3.586 (1 Å], forming layers parallel to the ab plane.

Radiation induced emulsion polymerization

International Nuclear Information System (INIS)

Stannett, V.T.; Stahel, E.P.

1990-01-01

High energy radiation is particularly favored for the initiation of emulsion polymerization. The yield of free radicals, for example, from the radiolysis of the aqueous phase, is high; G(radical) values of 5-7. In addition, the rather special kinetics associated with emulsion polymerization lead, in general, to very large kinetic chain lengths, even with 'non-ideal' monomers such as vinyl acetate. Together, high polymerization rates at low doses become possible. There are some important advantages of radiation polymerization compared with chemical initiators, such as potassium persulfate. Perhaps the most important among them is the temperature independence of the initiation step. This makes low temperature polymerization very accessible. With monomers such as vinyl acetate, where chain termination to monomer is predominant, low temperatures lead to often highly desirable higher molecular weights. With styrene, the classical ideally behaved monomer, there are the advantages such as, for example, the feasibility of using cationic monomers. These and some attendant disadvantages are discussed in detail, including pilot plant studies

Reverse-osmosis membranes by plasma polymerization

Science.gov (United States)

Hollahan, J. R.; Wydeven, T.

1972-01-01

Thin allyl amine polymer films were developed using plasma polymerization. Resulting dry composite membranes effectively reject sodium chloride during reverse osmosis. Films are 98% sodium chloride rejective, and 46% urea rejective.

Role of electrolytes in the preparation of nanoparticles via the emulsion polymerization of vinyl pivalate.

Science.gov (United States)

Kikuchi, Kenji; Kitawaki, Mayuka; Suzuki, Atsushi; Oku, Takeo

2009-10-15

By controlling both the kind of ion and the ionic strength of electrolytes in an emulsion polymerization system of vinyl pivalate containing about 1% sodium lauryl sulfate as a surfactant, nanoparticles of polyvinylpivalate having a diameter of about 25 nm were successfully prepared. The use of high concentrations of lithium chloride and lithium sulfate (approximately 1.0 mol L(-1)) prevented the nanoparticles from aggregating and produced nanoparticles sizes of 25-50 nm. Ammonium acetate and sodium acetate, on the other hand, accelerated the aggregate of the nanoparticles. These phenomena were examined in detail and found to be similar to the Hofmeister phenomena and the combination rule proposed by Craig et al.

Crystal structures of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper and chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper

Energy Technology Data Exchange (ETDEWEB)

Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paholnitcaia, A. Yu. [State University of Moldova (Moldova, Republic of); Petrenko, P. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [State University of Moldova (Moldova, Republic of); Poirier, D. [Centre Hospitalier Universitaire de Quebec (Canada); Gulea, A. P. [State University of Moldova (Moldova, Republic of)

2015-01-15

Two crystal modifications of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper (I and II) and two modifications of chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper (III and IV) have been synthesized and studied by X-ray diffraction. In structures I and II, the copper atoms coordinate a monodeprotonated molecule of the organic ligand, nitrate ions, and a water molecule. In crystals of I, the complexes are monomeric, whereas complexes II are linked via nitrate ions to form polymeric chains. In both structures the coordination polyhedron of the copper atom can be described as a distorted tetragonal bipyramid—(4 + 1 + 1) in I and (4 + 2) in II. These coordination polyherdra have different compositions. In structures III and IV, the metal atoms coordinate a monodeprotonated (2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazole molecule and chloride ions. In III the complex-forming ion has square-planar coordination geometry, whereas structure IV consists of centrosymmetric dimers with two bridging chlorine atoms. It was found that nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper possesses antitumor activity.

Plasma polymerized high energy density dielectric films for capacitors

Science.gov (United States)

Yamagishi, F. G.

1983-01-01

High energy density polymeric dielectric films were prepared by plasma polymerization of a variety of gaseous monomers. This technique gives thin, reproducible, pinhole free, conformable, adherent, and insoluble coatings and overcomes the processing problems found in the preparation of thin films with bulk polymers. Thus, devices are prepared completely in a vacuum environment. The plasma polymerized films prepared all showed dielectric strengths of greater than 1000 kV/cm and in some cases values of greater than 4000 kV/cm were observed. The dielectric loss of all films was generally less than 1% at frequencies below 10 kHz, but this value increased at higher frequencies. All films were self healing. The dielectric strength was a function of the polymerization technique, whereas the dielectric constant varied with the structure of the starting material. Because of the thin films used (thickness in the submicron range) surface smoothness of the metal electrodes was found to be critical in obtaining high dielectric strengths. High dielectric strength graft copolymers were also prepared. Plasma polymerized ethane was found to be thermally stable up to 150 C in the presence of air and 250 C in the absence of air. No glass transitions were observed for this material.

Synthesis of Poly(vinyl ether) Thermoplastic Elastomers Having Functional Soft Segments

OpenAIRE

今枝, 嗣人; 漆崎, 美智遠; 阪口, 壽一; 橋本, 保; Tsuguto, IMAEDA; Michio, URUSHISAKI; Toshikazu, SAKAGUCHI; Tamotsu, HASHIMOTO

2013-01-01

The ABA-type triblock copolymers consisting of poly(2-adarnantyl vinyl ether) [poly(2-AdVE) as outer hard segments and poly(6-acetoxyhexyl vinyl ether) [poly(AcHVE)] poly(6-hydroxyhexyl vinyl ether) [poly(H HVE)], or poly(2-(2-methoxyethoxy)ethyl vinyl ether [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxy, and oxyethylene units in their soft segments, the two polymer seg...

Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives

Directory of Open Access Journals (Sweden)

Malwina Krause

2017-03-01

Full Text Available The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABAA receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines reported from the year 2000 to date, including structure–activity relationships.

Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives.

Science.gov (United States)

Krause, Malwina; Foks, Henryk; Gobis, Katarzyna

2017-03-04

The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABA A receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5- b ]pyridines and imidazo[4,5- c ]pyridines reported from the year 2000 to date, including structure-activity relationships.

3-Ethyl-5-(4-methoxyphenoxy-2-(pyridin-4-yl-3H-imidazo[4,5-b]pyridine

Directory of Open Access Journals (Sweden)

S. Ranjith

2011-07-01

Full Text Available In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5°]. The pyridine ring makes a dihedral angle of 35.5 (5° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking interaction between the phenyl rings of neighbouring molecules [centroid–centroid distance = 3.772 (2 Å, interplanar distance = 3.546 (2 Å and slippage = 1.286 (2 Å].

Tailor-made starch-based conjugates containing well-defined poly(vinyl acetate and its derivative poly(vinyl alcohol

Directory of Open Access Journals (Sweden)

2011-06-01

Full Text Available Reversible addition-fragmentation chain transfer (RAFT polymerization was adopted to synthesize starch-based conjugates that possessed controllable architecture and properties. Starch-based xanthate agent was prepared and applied as chain transfer agent to conduct the living/controlled polymerization (LCP of vinyl acetate, which generated tailor-made conjugates of starch and well-defined poly(vinyl acetate (SVAc. The relevant derivatives, conjugates of starch and chain length-controlled poly(vinyl alcohol (SVA, were obtained subsequently. Various characterizations such as Fourier transform infrared spectra (FTIR, ultraviolet-visible spectroscopy (UV, proton nuclear magnetic resonance (1H NMR, gel permeation chromatography (GPC, X-ray diffraction (XRD, Thermogravimetric analysis (TGA, and dynamic mechanical thermal analysis (DMTA were performed to examine the structure of intermediates and the starch-based conjugates. Static contact angle measurements revealed that the hydrophilic character of starch-based conjugates was tunable. Well-defined SVAc was amphiphilic and it was able to self-assemble into size controllable micelles, which was verified by contact angles, transmission electron microscopy (TEM and dynamic light scattering (DLS tests. SVA exhibited much higher capability to form physically cross-linked hydrogel than starch did. Both the characteristic of SVAc and SVA were chain length-dependent.

trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

Science.gov (United States)

Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

2009-01-01

In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

Polysulfone hemodiafiltration membranes with enhanced anti-fouling and hemocompatibility modified by poly(vinyl pyrrolidone) via in situ cross-linked polymerization

Energy Technology Data Exchange (ETDEWEB)

Zhu, Lijing, E-mail: zhulijing@nimte.ac.cn; Song, Haiming; Wang, Jiarong; Xue, Lixin, E-mail: xuelx@nimte.ac.cn

2017-05-01

Poly(vinyl pyrrolidone) (PVP) and its copolymers have been widely employed for the modification of hemodiafiltration membranes due to their excellent hydrophilicity, antifouling and hemocompatibility. However, challenges still remain to simplify the modification procedure and to improve the utilization efficiency. In this paper, antifouling and hemocompatibility polysulfone (PSf) hemodiafiltration membranes were fabricated via in situ cross-linked polymerization of vinyl pyrrolidone (VP) and vinyltriethoxysilane (VTEOS) in PSf solutions and non-solvent induced phase separation (NIPS) technique. The prepared membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which suggested that VP and VTEOS have been cross-linked copolymerized in PSf membranes. The modified PSf membranes with high polymer content showed improved hydrophilicity, ultrafiltration and protein antifouling ability. In addition, the modified PSf membranes showed lower protein adsorption, inhibited platelet adhesion and deformation, prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), and decreased the content of fibrinogen (FIB) transferring to fibrin, indicating enhanced hemocompatibility. In a word, the present work provides a simple and effective one-step modification method to construct PSf membranes with improved hydrophilicity, antifouling and hemocompatibility. - Highlights: • PSf membranes were modified by in situ cross-linked polymerization. • The modified PSf membranes showed enhanced hydrophilicity. • The anti-fouling and hemocompatibility of PSf membranes were improved.

Polysulfone hemodiafiltration membranes with enhanced anti-fouling and hemocompatibility modified by poly(vinyl pyrrolidone) via in situ cross-linked polymerization

International Nuclear Information System (INIS)

Zhu, Lijing; Song, Haiming; Wang, Jiarong; Xue, Lixin

2017-01-01

Poly(vinyl pyrrolidone) (PVP) and its copolymers have been widely employed for the modification of hemodiafiltration membranes due to their excellent hydrophilicity, antifouling and hemocompatibility. However, challenges still remain to simplify the modification procedure and to improve the utilization efficiency. In this paper, antifouling and hemocompatibility polysulfone (PSf) hemodiafiltration membranes were fabricated via in situ cross-linked polymerization of vinyl pyrrolidone (VP) and vinyltriethoxysilane (VTEOS) in PSf solutions and non-solvent induced phase separation (NIPS) technique. The prepared membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which suggested that VP and VTEOS have been cross-linked copolymerized in PSf membranes. The modified PSf membranes with high polymer content showed improved hydrophilicity, ultrafiltration and protein antifouling ability. In addition, the modified PSf membranes showed lower protein adsorption, inhibited platelet adhesion and deformation, prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), and decreased the content of fibrinogen (FIB) transferring to fibrin, indicating enhanced hemocompatibility. In a word, the present work provides a simple and effective one-step modification method to construct PSf membranes with improved hydrophilicity, antifouling and hemocompatibility. - Highlights: • PSf membranes were modified by in situ cross-linked polymerization. • The modified PSf membranes showed enhanced hydrophilicity. • The anti-fouling and hemocompatibility of PSf membranes were improved.

Immobilization/hybridization of amino-modified DNA on plasma-polymerized allyl chloride

International Nuclear Information System (INIS)

Zhang Zhihong; Feng Chuanliang

2007-01-01

The present work describes the fabrication and characterization of chloride-derivatized polymer coatings prepared by continuous wave (cw) plasma polymerization as adhesion layers in DNA immobilization/hybridization. The stability of plasma-polymerized allyl chloride (ppAC) in H 2 O was characterized by variation of the thickness of polymer films and its wettability was examined by water contact angle technique. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to study polymer matrix properties and oligonucleotide/DNA binding interaction. With the same carrier gas rate and process pressure, plasma polymers deposited at different input powers show various comparable immobilization properties; nevertheless, low input power plasma-polymerized films gives a lower sensitivity toward DNA binding than that from high input power plasma-deposited films. The following DNA immobilization on chloride-functionalized surfaces was found dependence on the macromolecular architecture of the plasma films. The hybridization between probe DNA and total mismatch target DNA shows no non-specific adsorption between target and ppAC

Resonance Raman assignment and evidence for noncoupling of individual 2- and 4-vinyl vibrational modes in a monomeric cyanomethemoglobin

International Nuclear Information System (INIS)

Gersonde, K.; Yu, N.T.; Lin, S.H.; Smith, K.M.; Parish, D.W.

1989-01-01

We have investigated the resonance Raman spectra of monomeric insect cyanomethemoglobins (CTT III and CTT IV) reconstituted with (1) protohemes IX selectively deuterated at the 4-vinyl as well as the 2,4-divinyls, (2) monovinyl-truncated hemes such as pemptoheme (2-hydrogen, 4-vinyl) and isopemptoheme (2-vinyl, 4-hydrogen), (3) symmetric hemes such as protoheme III (with 2- and 3-vinyls) and protoheme XIII (with 1- and 4-vinyls), and (4) hemes without 2- and 4-vinyls such as mesoheme IX, deuteroheme IX, 2,4-dimethyldeuteroheme IX, and 2,4-dibromodeuteroheme IX. Evidence is presented that the highly localized vinyl C = C stretching vibrations at the 2- and 4-positions of the heme in these cyanomet CTT hemoglobins are noncoupled and inequivalent; i.e., the 1631- and 1624-cm-1 lines have been assigned to 2-vinyl and 4-vinyl, respectively. The elimination of the 2-vinyl (in pemptoheme) or the 4-vinyl (in isopemptoheme) does not affect the C = C stretching frequency of the remaining vinyl. Furthermore, two low-frequency vinyl bending modes at 412 and 591 cm-1 exhibit greatly different resonance Raman intensities between 2-vinyl and 4-vinyl. The observed intensity at 412 cm-1 is primarily derived from 4-vinyl, whereas the 591-cm-1 line results exclusively from the 2-vinyl. Again, there is no significant coupling between 2-vinyl and 4-vinyl for these two bending modes

Antibacterial performance on plasma polymerized heptylamine films loaded with silver nanoparticles

Science.gov (United States)

Lin, Yu-Chun; Lin, Chia-Chun; Lin, Chih-Hao; Wang, Meng-Jiy

2017-01-01

The antibacterial performance of the plasma-polymerized (pp) heptylamine thin films loaded with silver nanoparticles was evaluated against the colonization of Escherichia coli and Staphylococcus aureus. The properties including the thickness and chemical composition of the as deposited HApp films were modulated by adjusting plasma parameters. The acquired results showed that the film thickness was controlled in the range of 20 to 400 nm by adjusting deposition time. The subsequent immersion of the HApp thin films in silver nitrate solutions result in the formation of amine-metal complexes, in which the silver nanoparticles were reduced directly on the matrices to form Ag@HApp. The reduction reaction of silver was facilitated by applying NaBH4 as a reducing agent. The results of physicochemical analyses including morphological analysis and ellipsometry revealed that the silver nanoparticles were successfully reduced on the HApp films, and the amount of reduced silver was closely associated which the thickness of the plasma-polymerized films, the concentration of applied metal ions solutions, and the time of immobilization. Regarding the antibacterial performance, the Ag@HApp films reduced by NaBH4 showed antibacterial abilities of 70.1 and 68.2% against E. coli and S. aureus, respectively.

Vapor phase reactions in polymerization plasma for divinylsiloxane-bis-benzocyclobutene film deposition

International Nuclear Information System (INIS)

Kinoshita, Keizo; Nakano, Akinori; Kawahara, Jun; Kunimi, Nobutaka; Hayashi, Yoshihiro; Kiso, Osamu; Saito, Naoaki; Nakamura, Keiji; Kikkawa, Takamaro

2006-01-01

Vapor phase reactions in plasma polymerization of divinylsiloxane-bis-benzocyclobutene (DVS-BCB) low-k film depositions on 300 mm wafers were studied using mass spectrometry, in situ Fourier transform infrared, and a surface wave probe. Polymerization via Diels-Alder cycloaddition reaction was identified by the detection of the benzocyclohexene group. Hydrogen addition and methyl group desorption were also detected in DVS-BCB monomer and related large molecules. The dielectric constant k of plasma polymerized DVS-BCB with a plasma source power range up to 250 W was close to ∼2.7 of thermally polymerized DVS-BCB, and increased gradually over 250 W. The electron density at 250 W was about 1.5x10 10 cm -3 . The increase of the k value at higher power was explained by the decrease of both large molecular species via multistep dissociation and incorporation of silica components into the polymer. It was found that the reduction of electron density as well as precursor residence time is important for the plasma polymerization process to prevent the excess dissociation of the precursor

Polymerization by plasma: surface treatment and plasma simulation

International Nuclear Information System (INIS)

Morales C, J.

2001-01-01

One of the general objectives that are developed by the group of polymers semiconductors in the laboratory of polymers of the UAM-Iztapalapa is to study the surface treatment for plasma of different materials. Framed in this general objective, in this work three lines of investigation have been developed, independent one of other that converge in the general objective. The first one tries about the modeling one and evaluation of the microscopic parameters of operation of the polymerization reactor. The second are continuation of the study of conductive polymers synthesized by plasma and the third are an application of the treatment for plasma on natural fibers. In the first one it lines it is carried out the characterization and simulation of the parameters of operation of the polymerization reactor for plasma. They are determined the microscopic parameters of operation of the reactor experimentally like they are the electronic temperature, the potential of the plasma and the density average of electrons using for it an electrostatic Langmuir probe. In the simulation, starting from the Boltzmann transport equation it thinks about the flowing pattern and the electronic temperature, the ions density is obtained and of electrons. The data are compared obtained experimentally with the results of the simulation. In second line a study is presented about the influence of the temperature on the electric conductivity of thin films doped with iodine, of poly aniline (P An/I) and poly pyrrole (P Py/I). The films underwent heating-cooling cycles. The conductivity of P An/I and P Py/I in function of the temperature it is discussed based on the Arrhenius model, showing that it dominates the model of homogeneous conductivity. It is also synthesized a polymer bi-layer of these two elements and a copolymer random poly aniline-poly pyrrole, of the first one it the behavior of its conductivity discusses with the temperature and of the second, the conductivity is discussed in

Structure of poly[diaqua[μ-1,2-bis(pyridin-4-ylethane-κ2N:N′]bis(μ3-cyclobutane-1,1-dicarboxylato-κ3O,O′:O′′:O′′′dimanganese(II

Directory of Open Access Journals (Sweden)

Do Nam Lee

2015-08-01

Full Text Available In the title compound, [Mn(C6H6O4(C12H12N2(H2O]n, the cyclobutane-1,1-dicarboxylate (cbdc ligands bridge three MnII ions, forming layers parallel to the ac plane. These layers are additionally connected by 1,2-bis(pyridin-4-ylethane ligands to form a three-dimensional polymeric framework. An inversion centre is located at the mid-point of the central C—C bond of the 1,2-bis(pyridin-4-ylethane ligand. The coordination geometry of the MnII ion is distorted octahedral and is built up by four carboxylate O atoms, one water O atom and a pyridyl N atom. The pyridine ligand and the coordinating water molecule are in a trans configuration. One carboxylate group of the cbdc ligand acts as a chelating ligand towards one MnII atom, whereas the second carboxylate group coordinates two different MnII atoms.

Pyridine Vapors Detection by an Optical Fibre Sensor

Directory of Open Access Journals (Sweden)

Alberto Fernandez-Gutiérrez

2008-02-01

Full Text Available An optical fibre sensor has been implemented towards pyridine vapors detection;to achieve this, a novel vapochromic material has been used, which, in solid state, suffers achange in colour from blue to pink-white in presence of pyridine vapours. This complex isadded to a solution of PVC (Poly Vinyl Chloride, TBP (Tributylphosphate andtetrahydrofuran (THF, forming a plasticized matrix; by dip coating technique, the sensingmaterial is fixed onto a cleaved ended optical fibre. The fabrication process was optimizedin terms of number of dips and dipping speed, evaluating the final devices by dynamicrange. Employing a reflection set up, the absorbance spectra and changes in the reflectedoptical power of the sensors were registered to determine their response. A linear relationbetween optical power versus vapor concentration was obtained, with a detection limit of 1ppm (v/v.

Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

Science.gov (United States)

Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

2015-01-02

A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nanomechanical and nanotribological properties of plasma nanotextured superhydrophilic and superhydrophobic polymeric surfaces

International Nuclear Information System (INIS)

Skarmoutsou, A; Charitidis, C A; Gnanappa, A K; Tserepi, A; Gogolides, E

2012-01-01

Oxygen plasma-induced surface modification of polymethylmethacrylate (PMMA), under plasma conditions favouring (maximizing) roughness formation, has been shown to create textured surfaces of roughness size and morphology dependent on the plasma-treatment time and subsequent morphology stabilization procedure. Superhydrophobic or superhydrophilic surfaces can thus be obtained, with potential applications in antireflective self-cleaning surfaces, microfluidics, wetting–dewetting control, anti-icing etc, necessitating determination of their mechanical properties. In this study, nanoindentation is used to determine the reduced modulus and hardness of the surface, while nanoscratch tests are performed to measure the coefficient of friction. The data are combined to assess the wear behaviour of such surfaces as a first guide for their practical applications. Short-time plasma treatment slightly changes mechanical, tribological and wear properties compared to untreated PMMA. However, a significant decrease in the reduced modulus and hardness and an increase in the coefficient of friction are observed after long plasma-treatment times. The C 4 F 8 plasma deposited thin hydrophobic layer on the polymeric surfaces (untreated and treated) reveals good adhesion, while its mechanical properties are greatly influenced by the substrate; it is also found that it effectively protects the polymeric surfaces, reducing plastic deformation. (paper)

Synthesis and polymerization of vinyl triazolium ionic liquids

Science.gov (United States)

Luebke, David; Nulwala, Hunaid; Matyjaszewski, Krzysztof; Adzima, Brian

2018-05-15

Herein, we describe polymerized ionic liquids, demonstrate the synthesis of polymerized ionic liquids, and demonstrate the polymerization of triazolium monomers. One embodiment shows the polymeriazation of the triazolium monomers with bis(trifluoromethanesulfonyl)imide anions. In another embodiment we show the feasibility of copolymerizing with commodity monomers such as styrene using free radical polymerization techniques.

Complex-radical copolymerization of vinyl monomers on organoelemental initiators

International Nuclear Information System (INIS)

Grishin, D.F.

1993-01-01

Data on regularities of the initiation and growth of the (co)polymerization of polar vinyl series monomers on organo-elemental initiator, organo-boron in particular, are generalized. The effect of organo-metallic compounds and some phenol type inhibitors on the rate of acrylate (co)polymerization is analyzed from view of the change of electroacceptor properties (electrophilicity) of macroradicals

Review of some research work on surface modification and polymerizations by non-equilibrium plasma in Turkey

International Nuclear Information System (INIS)

Akovali, Guneri

2004-01-01

Non equilibrium plasma studies in Turkey can be considered as organized on two different lines: surface modification studies and plasma polymerization studies. Plasma surface modification studies: In different laboratories in Turkey the modification of materials' surfaces by plasma covers a wide spectra, for example: fibers (Carbon (CF) and polyacrylonitrile (PAN)), fabrics (PET/Cotton and PET/PA), biomaterials-food oriented (PU), denture Acrylic matrix, plasmochemical modification of a (PE and PP) film surface by several selected silicon and tin containing monomers, polymer blends and composites, recycled rubber and epoxy systems, etc. Plasma polymerization studies: This topic is accomplished by a great number of projects, for instance: plasma initiation polymerization and copolymerization of Styrene and MMA, Plasma-initiated polymerizations of Acrylamide (AA), kinetics of polymer deposition of several selected saturated hydrocarbons, silanization treatments by hexamethyldisilazane (HDMS), Plasma initiated polymerization (PIP) of allyl alcohol and 1-propano, (PSP) and (PIP) studies related to activated charcoal are done to explore their applications in haemoperfusion, an amperometric alcohol single-layer electrode is prepared by (EDA) plasma polymerization, preparation of mass sensitive immuno sensors and single layer multi enzyme electrodes by plasma polymerisation technique, etc

Syntheses of two potential dopamine D{sub 4} receptor radioligands: {sup 18}F labelled chromeno[3,4-c]pyridin-5-ones

Energy Technology Data Exchange (ETDEWEB)

Gu-Cai Li; Duan-Zhi Yin; Ming-Wei Wang; Deng-Feng Cheng; Yong-Xian Wang [Research Center of Radiopharmaceuticals, Shanghai Inst. of Applied Physics, Chinese Academy of Sciences, Shanghai, SH (China)

2006-07-01

The dopamine D{sub 4} receptor is hypothesized to relate with the pathophysiology and pharmacotherapy of schizophrenia while its level in brain regions is much lower and to date no suitable tracer is available for the study of D{sub 4} receptor in vivo. Therefore, selective imaging agents for the D{sub 4} subtype are badly needed. Based on the structure-activity analysis of chromeno[3,4-c]pyridin-5-ones as dopamine D{sub 4} receptor ligands, two fluorine-18 labelled chromeno[3,4-c] pyridin-5-one derivatives, 3-(4-[{sup 18}F]fluorobenzyl)-8-hydroxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one and 3-(4-[{sup 18}F]fluorobenzyl)-8,9-dimethoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one were synthesized through a two-step one-pot method. Their radiochemical yields were around 19.7% (decay-corrected) and radiochemical purities were higher than 95% with specific activities of about 120 GBq/{mu}mol. (orig.)

Preparation and characterization of film of poly vinyl acetate ethylene copolymer emulsion

International Nuclear Information System (INIS)

Zhang, Yanhua; Gu, Jiyou; Tan, Haiyan; Shi, Junyou; Di, Mingwei; Zuo, Yingfeng; Qiu, Si

2013-01-01

In order to improve the storage modulus and water resistance of poly (vinyl acetate), the vinyl acetate and poly (vinyl alcohol) (PVA) were respectively used as monomers and protective colloid to prepare a new kind of polyvinyl acetate emulsion adhesive by continuous emulsion polymerization. The dynamic mechanics, particle distribution, glass transition temperature, polymer emulsion structure of both polymerized and copolymerized emulsion were analyzed by SEM, DMA and XPS, respectively. The results indicated that the copolymerized emulsion has the appropriate particle size and the uniform particle distribution, the glass transition temperature increased from 50 °C to 70 °C, compared with poly (vinyl acetate). It could be seen from XPS spectra of copolymerized emulsion that key characteristic peak of C=O was still existent. X-ray photoelectron spectra revealed that the addition of EVA did not generate the new bond, whereas the maximum percentage increases in ester was determined in the composite film with the introduction of EVA of 25%, which indicated that the composite film has copolymer structure. The storage modulus and water resistance of poly (vinyl acetate) were improved due to the introduction of the EVA.

Plasma-polymerized hexamethyldisilazane treated by nitrogen plasma immersion ion implantation technique

Energy Technology Data Exchange (ETDEWEB)

Honda, R Y; Mota, R P; Batocki, R G S; Santos, D C R; Nicoleti, T; Kostov, K G; Kayama, M E; Algatti, M A [Laboratorio de Plasma, Faculdade de Engenharia, UNESP, Av. Dr Ariberto Pereira da Cunha-333, 12516-410, Guaratingueta, SP (Brazil); Cruz, N C [Laboratorio de Plasmas Tecnologicos, Unidade Diferenciada, UNESP, Av. Tres de Marco-511, 18085-180, Sorocaba, SP (Brazil); Ruggiero, L, E-mail: honda@feg.unesp.b [Faculdade de Ciencias, UNESP, Av. Luis E. Carrijo Coube 14-1, 17033-360, Bauru, SP (Brazil)

2009-05-01

This paper describes the effect of nitrogen Plasma Immersion Ion Implantation (PIII) on chemical structure, refraction index and surface hardness of plasma-polymerized hexamethyldisilazane (PPHMDSN) thin films. Firstly, polymeric films were deposited at 13.56 MHz radiofrequency (RF) Plasma Enhanced Chemical Vapour Deposition (PECVD) and then, were treated by nitrogen PIII from 15 to 60 min. Fourier Transformed Infrared (FTIR) spectroscopy was employed to analyse the molecular structure of the samples, and it revealed that vibrations modes at 3350 cm{sup -1}, 2960 cm{sup -1}, 1650 cm{sup -1}, 1250 cm{sup -1} and 1050 cm{sup -1} were altered by nitrogen PIII. Visible-ultraviolet (vis-UV) spectroscopy was used to evaluate film refractive index and the results showed a slight increase from 1.6 to 1.8 following the implantation time. Nanoindentation revealed a surface hardness rise from 0.5 to 2.3 GPa as PIII treatment time increased. These results indicate nitrogen PIII is very promising in improving optical and mechanical properties of PPHMDSN films.

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

International Nuclear Information System (INIS)

Hussain, Amreen A.; Pal, Arup R.; Kar, Rajib; Bailung, Heremba; Chutia, Joyanti; Patil, Dinkar S.

2014-01-01

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO 2 ) nanocomposite thin films. The deposition of PPani-TiO 2 nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO 2 nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO 2 nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H 2 SO 4 doping in PPani-TiO 2 nanocomposite. • PPani-TiO 2 nanocomposite based self-powered-hybrid photodetector

Electrocatalytic oxidations of pyridine derivatives using Ru(IV) poly pyridine complex

International Nuclear Information System (INIS)

Oliveira, S.M. de.

1989-01-01

The oxidation reactions electro catalysed by bi pyridine oxo tri pyridine ruthenium perchlorate metallic complex from selected organic substrates are studied. The obtained results are compared with forecasting results showing the coherence of suggested mechanism. The substrates 2-, 2- and 4- picolines with its respective 1-oxides and 1,2 -; 1,3 - and 1,4 - dimethyl pyridine chloride salts were analysed. The oxidation of toluene as reference substrate was also studied and the mass spectra of oxidation products were interpreted. (M.C.K.)

Synthesis of vinyl phosphites

International Nuclear Information System (INIS)

Kabachnik, M.M.; Novikova, Z.S.; Neganova, E.G.; Lutsenko, I.F.

1986-01-01

The authors investigated the reactions of phosphoriodidites and phosphinous iodides with a number of aldehydes and ketones in presence of tertiary amines (triethylamine, pyridine, N,N-diethylaniline), and they have shown that as a result of the reactions the corresponding vinyl esters of phosphorus acids are formed. The reactions of phosphoriodidites (and phosphorodiamidous iodides) with aliphatic aldehydes (acetaldehyde, propionaldehyde, butyraldehyde, and isobutyraldehyde) go at a molar reactant ratio of 1:1 in either at room temperature and are practically complete in 5-6 h. The yields of the alkenyl phosphites (phosphorodiamidites) were 45-70%. The compositions and structures of the compounds obtained were confirmed by elemental analysis and the IR and 1 H and 31 P NMR spectra

Co-polymer Films for Sensors

Science.gov (United States)

Ryan, Margaret A. (Inventor); Jewell, April D. (Inventor); Taylor, Charles (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Manatt, Kenneth S. (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor); Homer, Margie L. (Inventor); Shevade, Abhijit V. (Inventor)

2012-01-01

Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

Antifouling coatings via plasma polymerization and atom transfer radical polymerization on thin film composite membranes for reverse osmosis

Science.gov (United States)

Hirsch, Ulrike; Ruehl, Marco; Teuscher, Nico; Heilmann, Andreas

2018-04-01

A major drawback to otherwise highly efficient membrane-based desalination techniques like reverse osmosis (RO) is the susceptibility of the membranes to biofouling. In this work, a combination of plasma activation, plasma bromination and surface-initiated atom transfer radical polymerization (si-ATRP) of hydrophilic and zwitterionic monomers, namely hydroxyethyl methacrylate (HEMA), 2-methacryloyloxyethyl phosphorylcholine (MPC) and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), was applied to generate non-specific, anti-adhesive coatings on thin film composite (TFC) membranes. The antifouling effect of the coatings was shown by short-time batch as well as long-time steady state cultivation experiments with the microorganism Pseudomonas fluorescens. It could be shown that plasma functionalization and polymerization is possible on delicate thin film composite membranes without restricting their filtration performance. All modified membranes showed an increased resistance towards the adhesion of Pseudomonas fluorescens. On average, the biofilm coverage was reduced by 51.4-12.6% (for HEMA, SBMA, and MPC), the highest reduction was monitored for MPC with a biofilm reduction by 85.4%. The hydrophilic coatings applied did not only suppress the adhesion of Pseudomonas fluorescens, but also significantly increase the permeate flux of the membranes relative to uncoated membranes. The stability of the coatings was however not ideal and will have to be improved for future commercial use.

Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

Energy Technology Data Exchange (ETDEWEB)

Nath, Bhabesh Kumar; Khan, Aziz; Chutia, Joyanti, E-mail: jchutiaiasst@gmail.com

2015-10-15

Highlights: • Methyl methane sulfonate (MMS) is used as the sulfonating agent. • The proton conductivity of the membrane is found to be 0.141 S cm{sup −1}. • Power density of fuel cell with styrene/MMS membrane is 0.5 W cm{sup −2}. • The membrane exhibits thermal stability up to 140 °C. - Abstract: This work presents the introduction of an organic compound methyl methane sulfonate (MMS) for the first time in fabrication of polystyrene based proton exchange membrane (PEM) by plasma polymerization process. The membrane is fabricated by co-polymerizing styrene and MMS in capacitively coupled continuous RF plasma. The chemical composition of the plasma polymerized polymer membrane is investigated using Fourier Transform Infrared Spectroscopy which reveals the formation of composite structure of styrene and MMS. The surface morphology studied using AFM and SEM depicts the effect of higher partial pressure of MMS on surface topography of the membrane. The proton transport property of the membrane studied using electrochemical impedance spectroscopy shows the achievement of maximum proton conductivity of 0.141 S cm{sup −1} which is comparable to Nafion 117 membrane. Fuel cell performance test of the synthesized membrane shows a maximum power density of 500 mW cm{sup −2} and current density of 0.62 A cm{sup −2} at 0.6 V.

Properties of amine-containing coatings prepared by plasma polymerization

Czech Academy of Sciences Publication Activity Database

Choukourov, A.; Biederman, H.; Kholodkov, I.; Slavínská, D.; Trchová, Miroslava; Hollander, A.

2004-01-01

Roč. 92, č. 2 (2004), s. 979-990 ISSN 0021-8995 R&D Projects: GA MŠk ME 554 Institutional research plan: CEZ:AV0Z4050913 Keywords : plasma polymerization * thin films * functionalization Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.021, year: 2004

Radical-Mediated Enzymatic Polymerizations

Science.gov (United States)

Zavada, Scott R.; Battsengel, Tsatsral; Scott, Timothy F.

2016-01-01

Polymerization reactions are commonly effected by exposing monomer formulations to some initiation stimulus such as elevated temperature, light, or a chemical reactant. Increasingly, these polymerization reactions are mediated by enzymes―catalytic proteins―owing to their reaction efficiency under mild conditions as well as their environmental friendliness. The utilization of enzymes, particularly oxidases and peroxidases, for generating radicals via reduction-oxidation mechanisms is especially common for initiating radical-mediated polymerization reactions, including vinyl chain-growth polymerization, atom transfer radical polymerization, thiol–ene step-growth polymerization, and polymerization via oxidative coupling. While enzyme-mediated polymerization is useful for the production of materials intended for subsequent use, it is especially well-suited for in situ polymerizations, where the polymer is formed in the place where it will be utilized. Such polymerizations are especially useful for biomedical adhesives and for sensing applications. PMID:26848652

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

Energy Technology Data Exchange (ETDEWEB)

Hussain, Amreen A. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Pal, Arup R., E-mail: arpal@iasst.gov.in [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Kar, Rajib [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India); Bailung, Heremba; Chutia, Joyanti [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Patil, Dinkar S. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India)

2014-12-15

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO{sub 2}) nanocomposite thin films. The deposition of PPani-TiO{sub 2} nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO{sub 2} nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO{sub 2} nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H{sub 2}SO{sub 4} doping in PPani-TiO{sub 2} nanocomposite. • PPani-TiO{sub 2} nanocomposite based self-powered-hybrid photodetector.

Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

KAUST Repository

Gong, Dirong; Liu, Wen; Pan, Weijing; Chen, Tao; Jia, Xiaoyu; Huang, Kuo-Wei; Zhang, Xuequan

2015-01-01

Tridentate complexes Cr(III)Cl3L, [L = 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine], Fe(III)Cl3L, Fe(II)Cl2L and Co(II)Cl2L have been prepared and fully characterized. The solid structures of Cr(III)Cl3L, Fe(III)Cl3L and Co(II)Cl2L have been revealed by single crystal X-ray diffraction, and the Cr(III)Cl3L and Fe(III)Cl3L complexes both exhibit a distorted octahedral geometry, while the Co(II)Cl2L complex has a trigonal bipyramidal conformation. Four complexes have been examined in regioselective polymerization of butadiene in combination with MAO in toluene at room temperature. The trans-1,4, cis-1,4 enchainment of resultant polybutadiene are controlled by the metal center. Activated by MAO, complex Cr(III)Cl3L produces high level of trans-1,4 selectivity (trans-1,4 up to 93.3%) with moderate polymer yield, complexes Fe(III)Cl3L and Fe(II)Cl2L both show equal cis-1,4 and trans-1,4 with minor 1,2 selectivity (<10%), and Co(II)Cl2L catalyst displays predominated cis-1,4 selectivity, which can be shifted to 1,2 selectivity by adding PPh3 as an additive. Thus, tuning of the cis-1,4, trans-1,4 and 1,2 selectivity in full range via central metal and additive chosen by these 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine supported catalysts has been achieved. © 2015 Elsevier B.V. All rights reserved.

Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

KAUST Repository

Gong, Dirong

2015-05-21

Tridentate complexes Cr(III)Cl3L, [L = 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine], Fe(III)Cl3L, Fe(II)Cl2L and Co(II)Cl2L have been prepared and fully characterized. The solid structures of Cr(III)Cl3L, Fe(III)Cl3L and Co(II)Cl2L have been revealed by single crystal X-ray diffraction, and the Cr(III)Cl3L and Fe(III)Cl3L complexes both exhibit a distorted octahedral geometry, while the Co(II)Cl2L complex has a trigonal bipyramidal conformation. Four complexes have been examined in regioselective polymerization of butadiene in combination with MAO in toluene at room temperature. The trans-1,4, cis-1,4 enchainment of resultant polybutadiene are controlled by the metal center. Activated by MAO, complex Cr(III)Cl3L produces high level of trans-1,4 selectivity (trans-1,4 up to 93.3%) with moderate polymer yield, complexes Fe(III)Cl3L and Fe(II)Cl2L both show equal cis-1,4 and trans-1,4 with minor 1,2 selectivity (<10%), and Co(II)Cl2L catalyst displays predominated cis-1,4 selectivity, which can be shifted to 1,2 selectivity by adding PPh3 as an additive. Thus, tuning of the cis-1,4, trans-1,4 and 1,2 selectivity in full range via central metal and additive chosen by these 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine supported catalysts has been achieved. © 2015 Elsevier B.V. All rights reserved.

Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

Directory of Open Access Journals (Sweden)

Mohamed F. Abdel-Megeed

2013-01-01

Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

Studies on atom transfer radical polymerization of acrylates and styrenes with controlled polymeric block structures

OpenAIRE

Ibrahim, Khalid

2006-01-01

Atom transfer radical polymerization (ATRP) was applied to homo and block copolymerization of vinyl monomers methacrylates, acrylates, and styrene with iron (FeCl2.4H2O) as the transition metal in most cases. As complexing ligand either a commercially available ligand (triphenyl phosphine) (PPh3) or synthetic aliphatic amines were used. As initiators, methyl 2-bromopropionate, ethyl 2-bromoisobutyrate, α,α-dichloroacetophenone, and poly(ethylene oxide) macroinitiator were employed. Block ...

Immobilization and controlled release of drug using plasma polymerized thin film

Energy Technology Data Exchange (ETDEWEB)

Myung, Sung-Woon [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of); Jung, Sang-Chul [Department of Environmental Engineering, Sunchon National University, Sunchon 540-742 (Korea, Republic of); Kim, Byung-Hoon, E-mail: kim5055@chosun.ac.kr [Department of Dental Materials, School of Dentistry, MRC Center, Chosun University, 309 Pilmun-daero, Dong-gu, Gwangju (Korea, Republic of)

2015-06-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release.

Immobilization and controlled release of drug using plasma polymerized thin film

International Nuclear Information System (INIS)

Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

2015-01-01

In this study, plasma polymerization of acrylic acid was employed to immobilize drug and control its release. Doxorubicin (DOX) was immobilized covalently on the glass surface deposited with plasma polymerized acrylic acid (PPAAc) thin film containing the carboxylic group. At first, the PPAAc thin film was coated on a glass surface at a pressure of 1.33 Pa and radio frequency (RF) discharge power of 20 W for 10 min. DOX was immobilized on the PPAAc deposition in a two environment of phosphate buffer saline (PBS) and dimethyl sulfoxide (DMSO) solutions. The DOX immobilized surface was characterized by scanning electron microscope, atomic force microscope and attenuated total reflection Fourier transform infrared spectroscopy. The DOX molecules were more immobilized in PBS than DMSO solution. The different immobilization and release profiles of DOX result from the solubility of hydrophobic DOX in aqueous and organic solutions. Second, in order to control the release of the drug, PPAAc thin film was covered over DOX dispersed layer. Different thicknesses and cross-linked PPAAc thin films by adjusting deposition time and RF discharge power were covered on the DOX layer dispersed. PPAAc thin film coated DOX layer reduced the release rate of DOX. The thickness control of plasma deposition allows controlling the release rate of drug. - Highlights: • Doxorubicin was immobilized on the surface of plasma polymerized acrylic acid thin film. • Release profile of doxorubicin was affected by aqueous and organic solutions. • Plasma polymerized acrylic acid thin film can be used to achieve controlled release

Synthesis and crystal structures of 2-methyl-4-aryl-5-oxo-5H-indeno [1,2-b] pyridine carboxylate derivatives

DEFF Research Database (Denmark)

Pandian, Ramesh; Naushad, Edayadulla; Vijayakumar, Vinodhkumar

2014-01-01

pyridine derivatives through oxidation. Consequently, the interest in this aromatization reaction, investigation of a wide range of 1, 4-DHPs continues to attract the attention of researchers. Herein, we report the preparation of pyridine derivatives and the crystal structures determined by X......-ray crystallographic methods.Results: The crystal structures and conformational studies of two organic compounds, namely ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (I) and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (II) are reported. The terminal ethyl......) dimer running along 011 direction.Conclusion: The crystal structures ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate have been investigated in detail. The terminal ethyl group of compound I...

Polymerization of impregnated monomer in wood by microwave irradiation

International Nuclear Information System (INIS)

Kawase, Kaoru; Hayakawa, Kiyoshi

1976-01-01

The manufacturing of a wood-plastic combination (WPC) by irradiation of microwave (2,450 and 915 +- 50 MHz) or gamma-ray was carried out. After the impregnation of dry woods (Hinoki: Chamaecyparis obtusa Endl., Buna: Acer mono Maxim., and Kaede: Fagus crenata Blume) with the mixture of the vinyl monomers and chemical reagents, the monomer in wood was polymerized by irradiation. In case of polymerization with microwave (2,450 MHz) the effect of oxygen was not recognized, but in the case of gamma-ray the rate of polymerization remarkably decreased in the presence of oxygen. The polymerization of various monomers was carried out also in the air, and the conversions of styrene, methyl-, ethyl-, n-propyl-, and n-butyl-methacrylate were 51.8 -- 89.1%, but that of vinyl acetate was lower (4.3 -- 8.2%). The conversion of monomers with irradiation of 915 MHz microwave was very low (2.6 -- 33.5%). The conversion of monomers increased when toluylene diisocyanate was added in the monomers. The percentage of extraction with hot benzene of WPC (chip) decreased by the addition of toluylene diisocyanate. It was concluded from C.H.N. analyses that the reaction took place among the wood, toluylene diisocyanate and methyl methacrylate. (auth.)

The role of the Quinonine and Pyridine added to catechol to improve the efficiency of dye sensitized solar cell: An ab initio study

International Nuclear Information System (INIS)

Tuan, Mai Anh; Ha, Nguyen Ngoc; Trung, Vu Quoc; Thu Thuy, Luong T.; Thu, Dang Xuan

2012-01-01

Highlights: ► Detailed mechanism of Dye-to-TiO 2 charge-transfer (dye = Cat, Cat-v-P or Cat-v-Q). ► The efficiency of the electron transition can be improved by adding n-type donor. ► The donor should have conjugated structure for easy electron transfer. - Abstract: Recently, dye-sensitized solar cell (DSSC) has attracted the attention of research worldwide and become a low-cost solar cell with highest efficiencies exceeding 11%. To date, many works have been devoted to improve the efficiencies of DSSC by both materials and electrical approach. Our (TD)DFT-based procedure made it possible to get insights into the geometrical and electronic structures of the dyes and to unravel the structural modifications optimizing the properties of Catechol-based DSSC. We try to explain the electron injection pathways of Catechol (Cat), (pyridin-4-yl)vinyl and (quinolinyl)vinyl to Catechol (known as Cat-v-P and Cat-v-Q) bound to TiO 2 cluster and explain the role of Quinonine and Pyridine, as electron donor, to Catechol which contribute to increase the quality factor of the cell.

Immobilization of biomolecules to plasma polymerized pentafluorophenyl methacrylate.

Science.gov (United States)

Duque, Luis; Menges, Bernhard; Borros, Salvador; Förch, Renate

2010-10-11

Thin films of plasma polymerized pentafluorophenyl methacrylate (pp-PFM) offer highly reactive ester groups throughout the structure of the film that allow for subsequent reactions with different aminated reagents and biological molecules. The present paper follows on from previous work on the plasma deposition of pentafluorophenyl methacrylate (PFM) for optimum functional group retention (Francesch, L.; Borros, S.; Knoll, W.; Foerch, R. Langmuir 2007, 23, 3927) and reactivity in aqueous solution (Duque, L.; Queralto, N.; Francesch, L.; Bumbu, G. G.; Borros, S.; Berger, R.; Förch, R. Plasma Process. Polym. 2010, accepted for publication) to investigate the binding of a biologically active peptide known to induce cellular adhesion (IKVAV) and of biochemically active proteins such as BSA and fibrinogen. Analyses of the films and of the immobilization of the biomolecules were carried out using infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The attachment of the biomolecules on pulsed plasma polymerized pentafluorophenyl methacrylate was monitored using surface plasmon resonance spectroscopy (SPR). SPR analysis confirmed the presence of immobilized biomolecules on the plasma polymer and was used to determine the mass coverage of the peptide and proteins adsorbed onto the films. The combined analysis of the surfaces suggests the covalent binding of the peptide and proteins to the surface of the pp-PFM.

2-(4-Methylpiperazin-1-yl-4-phenyl-6-(thiophen-2-yl-pyridine-3-carbonitrile

Directory of Open Access Journals (Sweden)

Nawal Mishriky

2013-02-01

Full Text Available 2-(4-Methylpiperazin-1-yl-4-phenyl-6-(thiophen-2-yl-pyridine-3-carbonitrile (4 was synthesized via nucleophilic substitution reaction of 1-methylpiperazine with 2-bromo analogue 3. The latter was obtained through bromination (Br2/AcOH of 2-[3-oxo-1-phenyl-3-(thiophen-2-ylpropyl]malononitrile (2.

Simple and fast polydimethylsiloxane (PDMS) patterning using a cutting plotter and vinyl adhesives to achieve etching results.

Science.gov (United States)

Hyun Kim; Sun-Young Yoo; Ji Sung Kim; Zihuan Wang; Woon Hee Lee; Kyo-In Koo; Jong-Mo Seo; Dong-Il Cho

2017-07-01

Inhibition of polydimethylsiloxane (PDMS) polymerization could be observed when spin-coated over vinyl substrates. The degree of polymerization, partially curing or fully curing, depended on the PDMS thickness coated over the vinyl substrate. This characteristic was exploited to achieve simple and fast PDMS patterning method using a vinyl adhesive layer patterned through a cutting plotter. The proposed patterning method showed results resembling PDMS etching. Therefore, patterning PDMS over PDMS, glass, silicon, and gold substrates were tested to compare the results with conventional etching methods. Vinyl stencils with widths ranging from 200μm to 1500μm were used for the procedure. To evaluate the accuracy of the cutting plotter, stencil designed on the AutoCAD software and the actual stencil widths were compared. Furthermore, this method's accuracy was also evaluated by comparing the widths of the actual stencils and etched PDMS results.

Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

Directory of Open Access Journals (Sweden)

Zong-Cheng Chen

2014-09-01

Full Text Available In this paper, we propose a simple one-pot methodology for proceeding from atom transfer reaction-induced conventional free radical polymerization (AT-FRP to atom transfer self-condensing vinyl polymerization (AT-SCVP through manipulation of the catalyst phase homogeneity (i.e., CuBr/2,2'-bipyridine (CuBr/Bpy in a mixture of styrene (St, 4-vinyl benzyl chloride (VBC, and ethyl 2-bromoisobutyrate. Tests of the solubilities of CuBr/Bpy and CuBr2/Bpy under various conditions revealed that both temperature and solvent polarity were factors affecting the solubility of these copper complexes. Accordingly, we obtained different polymer topologies when performing AT-SCVP in different single solvents. We investigated two different strategies to control the polymer topology in one-pot: varying temperature and varying solvent polarity. In both cases, different fractions of branching revealed the efficacy of varying the polymer topology. To diversify the functionality of the peripheral space, we performed chain extensions of the resulting hyperbranched poly(St-co-VBC macroinitiator (name as: hbPSt MI with either St or tBA (tert-butyl acrylate. The resulting hyperbranched core star polymer had high molecular weights (hbPSt-g-PSt: Mn = 25,000, Đ = 1.77; hbPSt-g-PtBA: Mn = 27,000, Đ = 1.98; hydrolysis of the tert-butyl groups of the later provided a hyperbranched core star polymer featuring hydrophilic poly(acrylic acid segments.

Hydrophobic Coatings on Cotton Obtained by in Situ Plasma Polymerization of a Fluorinated Monomer in Ethanol Solutions.

Science.gov (United States)

Molina, Ricardo; Teixidó, Josep Maria; Kan, Chi-Wai; Jovančić, Petar

2017-02-15

Plasma polymerization using hydrophobic monomers in the gas phase is a well-known technology to generate hydrophobic coatings. However, synthesis of functional hydrophobic coatings using plasma technology in liquids has not yet been accomplished. This work is consequently focused on polymerization of a liquid fluorinated monomer on cotton fabric initiated by atmospheric plasma in a dielectric barrier discharge configuration. Functional hydrophobic coatings on cotton were successfully achieved using in situ atmospheric plasma-initiated polymerization of fluorinated monomer dissolved in ethanol. Gravimetric measurements reveal that the amount of polymer deposited on cotton substrates can be modulated with the concentration of monomer in ethanol solution, and cross-linking reactions occur during plasma polymerization of a fluorinated monomer even without the presence of a cross-linking agent. FTIR and XPS analysis were used to study the chemical composition of hydrophobic coatings and to get insights into the physicochemical processes involved in plasma treatment. SEM analysis reveals that at high monomer concentration, coatings possess a three-dimensional pattern with a characteristic interconnected porous network structure. EDX analysis reveals that plasma polymerization of fluorinated monomers takes place preferentially at the surface of cotton fabric and negligible polymerization takes place inside the cotton fabric. Wetting time measurements confirm the hydrophobicity of cotton coatings obtained although equilibrium moisture content was slightly decreased. Additionally, the abrasion behavior and resistance to washing of plasma-coated cotton has been evaluated.

Flame retardant cotton fabrics by electron beam-induced polymerization of vinyl phosphonate oligomer

International Nuclear Information System (INIS)

Sawai, Takeshi; Ametani, Kazuo; Enomoto, Ichiro

1988-01-01

Vinyl phosphonate oligomer is presently used commercially as a cellulosic flame retardant in conjugation with N-methylol acrylamide, using a persulfate catalyst and a thermal cure. This combination can also be cured at room temperature with electron beams, as can the vinyl phosphonate alone. For the textile application, fixation of flame retardants by electron beams with low energy is one of the most promising applications. For the purpose of preparing flame resistant cotton fabrics such as bed sheets and pajamas, flame retardant curing of vinyl phosphonate oligomer on cotton fabrics was examined using electron beams from a self-sealed electron beam processor and gamma rays from a 60 Co source. A joint investigation was undertaken by the Tokyo Metropolitan Textile Research Institute and Tokyo Metropolitan Isotope Research Center to determine the feasibility of curing vinyl phosphonate oligomer on the cotton fabrics for textile finishing. (author)

Study on the role of active radicals on plasma sterilization inside small diameter flexible polymeric tubes

Science.gov (United States)

Mstsuura, Hiroto; Fujiyama, Takatomo; Okuno, Yasuki; Furuta, Masakazu; Okuda, Shuichi; Takemura, Yuichiro

2015-09-01

Recently, atmospheric pressure discharge plasma has gathered attention in various fields. Among them, plasma sterilization with many types of plasma source has studied for decades and its mechanism is still an open question. If active radicals produced in plasma has main contribution of killing bacterias, direct contact of the so-called plasma flame might not be necessary. To confirm this, sterilization inside small diameter flexible polymeric tubes is studied in present work. DBD type plasma jet is produce by flowing helium gas in a glass tube. A long polymeric tube is connected and plasma jet is introduced into it. Plasma flame length depends on helium gas flow rate, but limited to about 10 cm in our experimental condition. E.colis set at the exit plasma source is easily killed during 10 min irradiation. At the tube end (about 20 cm away from plasma source exit), sterilization is possible with 30 min operation. This result shows that active radical is produced with helium plasma and mist contained in sample, and it can be transferred more than 20 cm during it life time. More plasma diagnostic data will also be shown at the conference. This work was partially supported by the ''ZE Research Program, IAE(ZE27B-4).

Vinyl Monomers Double as UV Stabilizers: 179th ACS Meeting Houston.

Science.gov (United States)

Chemical and Engineering News, 1980

1980-01-01

Synthesis and polymerization of vinyl monomers that double as stabilizers against degradation of plastics by ultraviolet light has been accomplished. Potential applications include protection of photovoltaic cells in solar power plants. (Author/RE)

Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

KAUST Repository

Batool, Farhat

2016-11-18

Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

KAUST Repository

Batool, Farhat; Emwas, Abdul-Hamid M.; Gao, Xin; Munawar, Munawar A.; Chotana, Ghayoor A.

2016-01-01

Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

STUDIES ON VINYL POLYMERIZATION WITH INITIATION SYSTEM CONTAINING AMINE DERIVATIVES

Institute of Scientific and Technical Information of China (English)

QIU Kunyuan; ZHANG Jingyi; FENG Xinde(S. T. Voong)

1983-01-01

Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET＞DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET＞DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of Rp=K [DMT]1/2 [MEMA]3/2 was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.

Preparation of Ethylene Vinyl Acetate/Zeolite 4A Mixed Matrix Membrane for CO2/N2 Separation

Directory of Open Access Journals (Sweden)

Iman Khalilinejad

2016-07-01

Full Text Available A great contribution in research activities on carbon dioxide (CO2 separation, as the most important challenge in greenhouse gases control, has been made to develop new polymeric membranes. In this case, mixed matrix membranes (MMMs, comprised of rigid particles dispersed in a continuous polymeric matrix, was proposed as an effective method to improve the separation properties of polymeric membranes. In this research, ethylene vinyl acetate (EVA copolymer and zeolite 4A powders were applied to prepare MMMs using solution casting/solvent evaporation method and CO2/N2 separation performance of the membranes was examined under different feed pressures (3-8 bar and operating temperatures (25-50°C. Morphological and structural characterizations of the membranes were evaluated using scanning electron microscopy (SEM, Fourier transform infrared (FTIR spectroscopy, differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, density and solvent-induced swelling measurements. The gas permeability measurements through the constant-volume method showed the permeability of two gases increased in the presence of zeolite 4A nanoparticles in the polymer matrix. Calculation of diffusivity coefficients of gases revealed that improvement in the diffusivity of all gases into membrane matrix was the main reason for permeability enhancement. In addition, the increase in the CO2/N2 ideal selectivity with the presence of zeolite 4A nanoparticles in the polymer matrix was attributed to the increment in CO2/N2 diffusion selectivity. Under optimum condition, with the addition of 10 wt% zeolite 4A nanoparticles into the membrane matrix, the CO2 permeability increased from 20.81 to 35.24 Barrer and its related selectivity increased 20% compared to that of neat EVA membrane. Furthermore, the membrane performances increased upon feed pressure rise, while the selectivity decreased with the increase in temperature.

Emulsion polymerization with high energy radiation

International Nuclear Information System (INIS)

Stannett, V.T.; Stahel, E.P.

1992-01-01

High energy radiation, particularly that of cobalt-60 or caesium-137 gamma-rays, provides in principle an ideal initiator for emulsion polymerization. The high free radical yields from the radiolysis of the aqueous phase combined with the high kinetic chain lengths associated with emulsion polymerization lead to a highly effective utilization of the radiation. There are other important advantages compared with the use of chemical initiators such as potassium persulfate. These are outlined in the chapter, together with some attendant disadvantages. Radiation-induced initiation is temperature independent, and low temperature polymerizations can be conducted with ease. Monomers that mainly terminate their growing chains by chain transfer to monomer give higher molecular weights at lower temperatures. Industrially, vinyl acetate is an important example of such a monomer, and it has been studied using radiation initiation. Both laboratory and pilot plant studies have been carried out and reported. The results are summarized in this chapter. Styrene is the classical example of a material that under a number of conditions closely obeys the so-called ideal Smith-Ewart kinetics. It has been found that under similar conditions but substituting radiation for potassium persulfate as the initiator, ideal kinetics were closely followed. Most of the conventional and some non-standard vinyl and diene monomers have been studied to some extent with radiation-initiated polymerizations in emulsion. To conserve space however, this chapter presents and discusses the results obtained only with styrene and vinyl acetate, both in laboratory and pilot plant investigations. Other monomers and special situations are referenced either directly or to the other available reviews. (orig.)

A plasma polymerization technique to overcome cerebrospinal fluid shunt infections

Energy Technology Data Exchange (ETDEWEB)

Coekeliler, D [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey); Caner, H [Department of Neurosurgery, School of Medicine, Baskent University, 06610, Ankara (Turkey); Zemek, J [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53, Prague, Czech Republic (Czech Republic); Choukourov, A [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Biederman, H [Department of Macromolecular Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Mutlu, M [Plasma Aided Bioengineering and Biotechnology Research Laboratory, Engineering Faculty, Hacettepe University, 06532, Ankara (Turkey)

2007-03-01

Prosthetic devices, mainly shunts, are frequently used for temporary or permanent drainage of cerebrospinal fluid. The pathogenesis of shunt infection is a very important problem in modern medicine and generally this is characterized by staphylococcal adhesion to the cerebrospinal fluid shunt surfaces. In this paper, the prevention of the attachment of test microorganism Staphylococcus epidermidis on the cerebrospinal fluid shunt surfaces by 2-hydroxyethylmethacrylate (HEMA) precursor modification in the plasma polymerization system, is reported. Different plasma polymerization conditions (RF discharge power 10-20-30 W, exposure time 5-10-15 min) were employed during the surface modification. The surface chemistry and topology of unmodified and modified shunts was characterized by x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Also, static contact angle measurements were performed to state the change of surface hydrophilicity. All samples were tested in vitro with Staphylococcus epidermidis. A plasma-polymerized HEMA film (PP HEMA) was found to be an alternative simple method to decrease the microorganism attachment and create bacterial anti-fouling surfaces. The attachment of the model microorganism Staphylococcus epidermidis on the shunt surface modified by PP HEMA at 20 W and 15 min was reduced 62.3% if compared to the unmodified control surface of the shunt.

Macrocyclic ligands for uranium complexation

International Nuclear Information System (INIS)

Potts, K.T.

1991-04-01

A highly preorganized 24-macrocycle containing biuret, thiobiuret and pyridine subunits has been prepared by high dilution ring-closure procedures. Intermediate products to this macrocycle have been utilized to extend this synthetic route to include further representatives where solubility and stability will be influenced by substituent variation. A 1:1 complex has been formed from uranyl acetate and a quinquepyridine derivative, this representing a new type of ligand for the uranyl ion. A very convenient synthetic procedure that will allow the incorporation of these macrocycles into polymeric systems has been developed for the introduction of a vinyl substituent into the 4-position of the pyridine ring. Using triflate, vinyltributyltin and Pd 0 chemistry, this procedure should make a variety of substituted 4-vinylpyridines available for the first time. 3 refs

Deposition of polymeric perfluored thin films in proton ionic membranes by plasma processes

International Nuclear Information System (INIS)

Polak, Peter Lubomir; Mousinho, Ana Paula; Ordonez, Nelson; Silva Zambom, Luis da; Mansano, Ronaldo Domingues

2007-01-01

In this work the surfaces of polymeric membranes based on Nafion (proton conducting material), used in proton exchange membranes fuel cells (PEMFC) had been modified by plasma deposition of perfluored polymers, in order to improve its functioning in systems of energy generation (fuel cells). The deposition increases the chemical resistance of the proton ionic polymers without losing the electrical properties. The processing of the membranes also reduces the permeability of the membranes to the alcohols (methanol and ethanol), thus preventing poisoning of the fuel cell. The processing of the membranes of Nafion was carried through in a system of plasma deposition using a mixture of CF 4 and H 2 gases. The plasma processing was made mainly to increase the chemical resistance and result in hydrophobic surfaces. The Fourier transformed infrared (FTIR) technique supplies a spectrum with information about the CF n bond formation. Through the Rutherford back scattering (RBS) technique it was possible to verify the deposition rate of the polymeric layer. The plasma process with composition of 60% of CF 4 and 40% of H 2 presented the best deposition rate. By the spectrum analysis for the optimized configuration, it was possible to verify that the film deposition occurred with a thickness of 90 nm, and fluorine concentration was nearly 30%. Voltammetry made possible to verify that the fluorination increases the membranes chemical resistance, improving the stability of Nafion, becoming an attractive process for construction of fuel cells

Polythiophene films obtained by polymerization under atmospheric pressure plasma conditions

Energy Technology Data Exchange (ETDEWEB)

Teslaru, T.; Topala, I., E-mail: ionut.topala@uaic.ro; Dobromir, M.; Pohoata, V.; Curecheriu, L.; Dumitrascu, N.

2016-02-01

The present work describes the experimental arrangement used to initiate polymerization reactions of thiophene monomer based on a dielectric barrier discharge with plane – parallel geometry, working at atmospheric pressure in argon, in turn to obtain conductive polymeric films for different applications. The resulting plasma polymerized polythiophene (pPTh) film was characterized by FT-IR, UV–Vis, XPS spectroscopy, AFM and contact angle measurements. Characterization of pPTh films showed a higher hydrophobic character and roughness, as compared with films obtained by chemical methods, and the thickness is depending on polymerization duration. Also it can conclude that our samples represent oxidised state of pPTh. As a possible application, it analysed in situ the iodine absorption phenomenon in the pPTh matrix and its time evolution by UV–Vis spectroscopy. The presence of iodine 3d{sub 5/2} and 3d{sub 3/2} peaks in the pPTh sample after absorption was identified by XPS spectroscopy. The hydrophobic pPTh film is transformed in a super hydrophilic film after absorption of iodine vapors. - Highlights: • We obtained polythiophene films (pPTh) by atmospheric pressure plasma technique. • The pPTh films showed a hydrophobic character and conducting properties. • The pPTh films were used as sensor for iodine vapors in biological environment.

1,4-Di(2-butoxycarbonyl-trans-vinyl-2,5-dimethoxybenzene

Directory of Open Access Journals (Sweden)

William A. Molano

2015-11-01

Full Text Available The title compound 1,4-di(2-butoxycarbonyl-trans-vinyl-2,5-dimethoxybenzene was synthesized in 94% yield through the Heck reaction between 2,5-diiodo-1,4-dimethoxybenzene and n-butyl acrylate, using bis(dibenzylideneacetone palladium(0 as homogeneous catalyst.

Modeling the chemistry of plasma polymerization using mass spectrometry.

Science.gov (United States)

Ihrig, D F; Stockhaus, J; Scheide, F; Winkelhake, Oliver; Streuber, Oliver

2003-04-01

The goal of the project is a solvent free painting shop. The environmental technologies laboratory is developing processes of plasma etching and polymerization. Polymerized thin films are first-order corrosion protection and primer for painting. Using pure acetylene we get very nice thin films which were not bonded very well. By using air as bulk gas it is possible to polymerize, in an acetylene plasma, well bonded thin films which are stable first-order corrosion protections and good primers. UV/Vis spectroscopy shows nitrogen oxide radicals in the emission spectra of pure nitrogen and air. But nitrogen oxide is fully suppressed in the presence of acetylene. IR spectroscopy shows only C=O, CH(2) and CH(3) groups but no nitrogen species. With the aid of UV/Vis spectra and the chemistry of ozone formation it is possible to define reactive traps and steps, molecule depletion and processes of proton scavenging and proton loss. Using a numerical model it is possible to evaluate these processes and to calculate theoretical mass spectra. Adjustment of theoretical mass spectra to real measurements leads to specific channels of polymerization which are driven by radicals especially the acetyl radical. The estimated theoretical mass spectra show the specific channels of these chemical processes. It is possible to quantify these channels. This quantification represents the mass flow through this chemical system. With respect to these chemical processes it is possible to have an idea of pollutant production processes.

Wettability, optical properties and molecular structure of plasma polymerized diethylene glycol dimethyl ether

Energy Technology Data Exchange (ETDEWEB)

Azevedo, T C A M; Algatti, M A; Mota, R P; Honda, R Y; Kayama, M E; Kostov, K G; Fernandes, R S [FEG-DFQ-UNESP, Av. Ariberto Pereira da Cunha 333, 12516-410 - Guaratingueta, SP (Brazil); Cruz, N C; Rangel, E C, E-mail: algatti@feg.unesp.b [UNESP, Avenida Tres de Marco, 511, 18087-180 Sorocaba, SP (Brazil)

2009-05-01

Modern industry has frequently employed ethylene glycol ethers as monomers in plasma polymerization process to produce different types of coatings. In this work we used a stainless steel plasma reactor to grow thin polymeric films from low pressure RF excited plasma of diethylene glycol dimethyl ether. Plasmas were generated at 5W RF power in the range of 16 Pa to 60 Pa. The molecular structure of plasma polymerized films and their optical properties were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet-Visible Spectroscopy, respectively. The IR spectra show C-H stretching at 3000-2900 cm{sup -1}, C=O stretching at 1730-1650 cm{sup -1}, C-H bending at 1440-1380 cm{sup -1}, C-O and C-O-C stretching at 1200-1000 cm{sup -1}. The refraction index was around 1.5 and the optical gap calculated from absorption coefficient presented value near 3.8 eV. Water contact angle of the films ranged from 40 deg. to 35 deg. with corresponding surface energy from 66 to 73x10{sup -7} J. Because of its favorable optical and hydrophilic characteristics these films can be used in ophthalmic industries as glass lenses coatings.

Effect of degree of polymerization and of temperature on the reactivity of poly(vinyl alcohol) by applying T-for-H exchange reaction

International Nuclear Information System (INIS)

Imaizumi, Hiroshi; Imai, Kazunari

1999-01-01

In order to reveal the effect of the degree of polymerization and of temperature on the reactivity of functional polymers, the hydrogen-isotope exchange reaction between poly(vinyl alcohol) (PVA) having each degree of polymerization and tritiated water vapor (HTO vapor) was dynamically observed at 35-80 deg C in a gas-solid system. The reason of the observation at 35 deg C is to clarify the possibility of the T-for-H exchange reaction at a temperature near the environment. The degree of polymerization of PVA used in this work was 500, 1000, 2000, 2800, or 3500. Applying the A''-McKay plot method to the data obtained in each observation, the rate constant (k) for each PVA in the reaction was calculated. Moreover, the Arrhenius plot for each PVA was made by using the k values. Comparing the k values and the results obtained previously, the following six matters have been clarified. In the temperature range of 35-80 deg C, the T-for-H exchange reaction between HTO vapor and each PVA occurred, and in this case, the atoms participating in the reaction are the H atoms in the OH groups in PVA and T atoms in HTO vapor. The reactivity of each PVA increases with rising temperature, and decreases with increasing the degree of polymerization. The rate of the decreasing of k with increasing the degree of polymerization changes at near the degree of polymerization of 1000, and the rate is fairly large under the degree of 1000. Under the degree of polymerization of 1000, the reactivity of PVA is more affected by the effect of the degree of polymerization than by the effect of temperature, and the reactivity is large when the degree of polymerization is small. Over the degree of polymerization of 1000, the reactivity of PVA is affected by both the degree of polymerization and temperature, and the reactivity is large when temperature is high. For the T-for-H exchange reaction in a gas-solid system, the reaction form is unchanged in the range of 35-80 deg C, and the reactivity at 35

Grafting of molecularly imprinted polymer to porous polyethylene filtration membranes by plasma polymerization.

Science.gov (United States)

Cowieson, D; Piletska, E; Moczko, E; Piletsky, S

2013-08-01

An application of plasma-induced grafting of polyethylene membranes with a thin layer of molecularly imprinted polymer (MIP) was presented. High-density polyethylene (HDPE) membranes, "Vyon," were used as a substrate for plasma grafting modification. The herbicide atrazine, one of the most popular targets of the molecular imprinting, was chosen as a template. The parameters of the plasma treatment were optimized in order to achieve a good balance between polymerization and ablation processes. Modified HDPE membranes were characterized, and the presence of the grafted polymeric layer was confirmed based on the observed weight gain, pore size measurements, and infrared spectrometry. Since there was no significant change in the porosity of the modified membranes, it was assumed that only a thin layer of the polymer was introduced on the surface. The experiments on the re-binding of the template atrazine to the membranes modified with MIP and blank polymers were performed. HDPE membranes which were grafted with polymer using continuous plasma polymerization demonstrated the best result which was expressed in an imprinted factor equal to 3, suggesting that molecular imprinting was successfully achieved.

catena-Poly[[[bis[aquanickel(II]bis(μ-pyridine-2,6-dicarboxylato N-oxide]-μ-1,2-di-4-pyridylethane] tetrahydrate

Directory of Open Access Journals (Sweden)

Ming-Hua Yang

2008-11-01

Full Text Available In the title compound, {[Ni2(C7H3NO52(C12H12N2(H2O2]·4H2O}n, two NiII ions, two tridentate pyridine-2,6-dicarboxylate N-oxide ligands and two coordinated water molecules form centrosymmetric dinuclear units, which are further bridged by centrosymmetric 1,2-di-4-pyridylethane ligands into polymeric chains along [210]. Each NiII ion has a distorted square-pyramidal environment, with the basal plane formed by three O [Ni—O = 1.9290 (16–1.9588 (10 Å] and one N [Ni—N = 1.9828 (18 Å] atoms and the apical position occupied by the water molecule [Ni—O = 2.2643 (11 Å]. The water molecules are involved in the formation of O—H...O hydrogen bonds.

Plasma-grafting polymerization on carbon fibers and its effect on their composite properties

Energy Technology Data Exchange (ETDEWEB)

Zhang, Huanxia, E-mail: zhanghuanxia818@163.com [College of Materials and Textile Engineering, Jiaxing University, Jiaxing 314001, Zhejiang (China); Li, Wei [College of Textile Engineering, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science and Technology, Ministry of Education, Shanghai 201620 (China)

2015-11-30

Graphical abstract: - Highlights: • A simple method to improve surface properties is applied to carbon fibers. • The maleic anhydride was grafted onto the carbon fiber with the FTIR spectra. • The plasma treatment time and polymerization condition affected on the grafting rate. • The carbon fibers exhibited excellent surface hydrophilicity and IFSS properties. - Abstract: Interfacial adhesion between matrix and fibers plays a crucial role in controlling the performance of composites. Carbon fibers have the major constraint of chemical interness and hence have limited adhesion with the matrix. Surface treatment of fibers is the best solution to this problem. In this work, carbon fibers were activated by plasma and grafting polymerization. The grafting ratio of polymerization was obtained by acid–base titration. The chemical and physical changes induced by the treatments on carbon fiber surface was examined using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR–ATR) technique. The interfacial adhesion of CF/EP (carbon fiber/epoxy) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. Experimental results show that the grafting rate was not only the function of the plasma-treat time but also the concentration of the grafting polymerization. The oxygen-containing groups (such as C−O, C=O, and O−C=O) and the interfacial shear strength (IFSS) of the plasma-grafting carbon fiber increased more significantly than the carbon fiber without plasma treatment grafted with MAH. This demonstrates that the surfaces of the carbon fiber samples are more active, hydrophilic, and rough after plasma-grafting treatments using a DBD operating in ambient argon mixture with oxygen. With DBD (dielectric barrier discharges) operating in ambient argon mixture with oxygen, the more active, hydrophilic, and rough surface was obtained by the

Plasma-grafting polymerization on carbon fibers and its effect on their composite properties

International Nuclear Information System (INIS)

Zhang, Huanxia; Li, Wei

2015-01-01

Graphical abstract: - Highlights: • A simple method to improve surface properties is applied to carbon fibers. • The maleic anhydride was grafted onto the carbon fiber with the FTIR spectra. • The plasma treatment time and polymerization condition affected on the grafting rate. • The carbon fibers exhibited excellent surface hydrophilicity and IFSS properties. - Abstract: Interfacial adhesion between matrix and fibers plays a crucial role in controlling the performance of composites. Carbon fibers have the major constraint of chemical interness and hence have limited adhesion with the matrix. Surface treatment of fibers is the best solution to this problem. In this work, carbon fibers were activated by plasma and grafting polymerization. The grafting ratio of polymerization was obtained by acid–base titration. The chemical and physical changes induced by the treatments on carbon fiber surface was examined using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR–ATR) technique. The interfacial adhesion of CF/EP (carbon fiber/epoxy) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. Experimental results show that the grafting rate was not only the function of the plasma-treat time but also the concentration of the grafting polymerization. The oxygen-containing groups (such as C−O, C=O, and O−C=O) and the interfacial shear strength (IFSS) of the plasma-grafting carbon fiber increased more significantly than the carbon fiber without plasma treatment grafted with MAH. This demonstrates that the surfaces of the carbon fiber samples are more active, hydrophilic, and rough after plasma-grafting treatments using a DBD operating in ambient argon mixture with oxygen. With DBD (dielectric barrier discharges) operating in ambient argon mixture with oxygen, the more active, hydrophilic, and rough surface was obtained by the

Polysulfone hemodiafiltration membranes with enhanced anti-fouling and hemocompatibility modified by poly(vinyl pyrrolidone) via in situ cross-linked polymerization.

Science.gov (United States)

Zhu, Lijing; Song, Haiming; Wang, Jiarong; Xue, Lixin

2017-05-01

Poly(vinyl pyrrolidone) (PVP) and its copolymers have been widely employed for the modification of hemodiafiltration membranes due to their excellent hydrophilicity, antifouling and hemocompatibility. However, challenges still remain to simplify the modification procedure and to improve the utilization efficiency. In this paper, antifouling and hemocompatibility polysulfone (PSf) hemodiafiltration membranes were fabricated via in situ cross-linked polymerization of vinyl pyrrolidone (VP) and vinyltriethoxysilane (VTEOS) in PSf solutions and non-solvent induced phase separation (NIPS) technique. The prepared membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), which suggested that VP and VTEOS have been cross-linked copolymerized in PSf membranes. The modified PSf membranes with high polymer content showed improved hydrophilicity, ultrafiltration and protein antifouling ability. In addition, the modified PSf membranes showed lower protein adsorption, inhibited platelet adhesion and deformation, prolonged the activated partial thromboplastin time (APTT), prothrombin time (PT), and decreased the content of fibrinogen (FIB) transferring to fibrin, indicating enhanced hemocompatibility. In a word, the present work provides a simple and effective one-step modification method to construct PSf membranes with improved hydrophilicity, antifouling and hemocompatibility. Copyright © 2017 Elsevier B.V. All rights reserved.

Biotransformation of ferulic acid to 4-vinyl guaiacol by Lactobacillus ...

African Journals Online (AJOL)

Continuously growing demand for natural flavors has led to a tremendous increase in biotransformation process employing microorganisms of different genera using ferulic acid (FA) as the precursor. In this study, potential of Lactobacillus farciminis (ATCC 29644) for biotransformation of FA to 4-vinyl guaiacol (4VG) was ...

Poly[tetraaqua-μ3-pyridine-3,5-dicarboxylato-strontium(II

Directory of Open Access Journals (Sweden)

Shirin Daneshvar

2008-02-01

Full Text Available The reaction of strontium(II nitrate with the proton-transfer compound (pdaH2(py-3,5-dc·H2O (where pda = propane-1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid leads to the formation of the title polymeric compound, [Sr(C7H3NO4(H2O4]n. The propane-1,3-diaminium cation is not incorporated in this crystal structure. The SrII atom lies on an inversion centre and is eight-coordinated by four O atoms from three py-3,5-dc ligands and four O atoms from four coordinated water molecules. The coordination polyhedron of the SrII atom is a distorted dodecahedron. These binuclear units are connected via the carboxylate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant interactions consisting of hydrogen bonds (X—H...O, with X = O and C and π–π stacking interactions [3.4604 (19 Å] connect the various components to form a supramolecular structure.

Evaluation of mechanism of cold atmospheric pressure plasma assisted polymerization of acrylic acid on low density polyethylene (LDPE) film surfaces: Influence of various gaseous plasma pretreatment

Science.gov (United States)

Ramkumar, M. C.; Pandiyaraj, K. Navaneetha; Arun Kumar, A.; Padmanabhan, P. V. A.; Uday Kumar, S.; Gopinath, P.; Bendavid, A.; Cools, P.; De Geyter, N.; Morent, R.; Deshmukh, R. R.

2018-05-01

Owing to its exceptional physiochemical properties, low density poly ethylene (LDPE) has wide range of tissue engineering applications. Conversely, its inadequate surface properties make LDPE an ineffectual candidate for cell compatible applications. Consequently, plasma-assisted polymerization with a selected precursor is a good choice for enhancing its biocompatibility. The present investigation studies the efficiency of plasma polymerization of acrylic acid (AAC) on various gaseous plasma pretreated LDPE films by cold atmospheric pressure plasma, to enhance its cytocompatibility. The change in chemical composition and surface topography of various gaseous plasma pretreated and acrylic deposited LDPE films has been assessed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The changes in hydrophilic nature of surface modified LDPE films were studied by contact angle (CA) analysis. Cytocompatibility of the AAC/LDPE films was also studied in vitro, using RIN-5F cells. The results acquired by the XPS and AFM analysis clearly proved that cold atmospheric pressure (CAP) plasma assisted polymerization of AAC enhances various surface properties including carboxylic acid functional group density and increased surface roughness on various gaseous plasma treated AAC/LDPE film surfaces. Moreover, contact angle analysis clearly showed that the plasma polymerized samples were hydrophilic in nature. In vitro cytocompatibility analysis undoubtedly validates that the AAC polymerized various plasma pretreated LDPE films surfaces stimulate cell distribution and proliferation compared to pristine LDPE films. Similarly, cytotoxicity analysis indicates that the AAC deposited various gaseous plasma pretreated LDPE film can be considered as non-toxic as well as stimulating cell viability significantly. The cytocompatible properties of AAC polymerized Ar + O2 plasma pretreated LDPE films were found to be more pronounced compared to the other plasma pretreated

Micro patterning of cell and protein non-adhesive plasma polymerized coatings for biochip applications

DEFF Research Database (Denmark)

Bouaidat, Salim; Berendsen, C.; Thomsen, P.

2004-01-01

Micro scale patterning of bioactive surfaces is desirable for numerous biochip applications. Polyethyleneoxide-like (PEO-like) coating with non-fouling functionality has been deposited using low frequency AC plasma polymerization. The non-fouling properties of the coating were tested with human c...... and versatility of the plasma-polymerized coatings, make this technology highly suitable for bio-MEMS and biochip applications, where patterned high contrast non-fouling surfaces are needed....

Unprecedentedly mild direct Pd-catalyzed arylation of oxazolo[4,5-b]pyridine

DEFF Research Database (Denmark)

Zhuravlev, Fedor

2006-01-01

Pd-catalyzed C-2 arylation of oxazolo[4,5-b]pyridine proceeds efficiently at 30 degrees C and tolerates a variety of aryl halides, including derivatized amino acids for which no racemization was observed during the reaction. Experimental evidence for facile deprotonation of oxazolo[4,5-b...

Structure of chlorinated poly(vinyl chloride). III. Preparation of poly(vinyl chloride)-β,β-d2 as a model for the study of the mechanism of chlorination and of the chlorinated poly(vinyl chloride) structure

International Nuclear Information System (INIS)

Lukas, R.; Kolinsky, M.

1976-01-01

A method for the preparation of poly(vinyl chloride)-β,β-d 2 (PVC-β,β-d 2 ) as a model for the investigation of the mechanism of chlorination and of the CPVC structure has been suggested. The conditions of preparation of deuterated intermediates of a multistage synthesis of vinyl chloride-β,β-d 2 and of suspension-polymerized PVC-β,β-d 2 have been described including the mass balance. Malonic acid was used as the starting compound. Tacticity values of a sample of PVC-β,β-d 2 and its infrared and nuclear magnetic resonance (NMR) spectra are presented and compared with the data already published

Influence of gamma irradiation on polymerization of pyrrole and glucose oxidase immobilization onto poly (pyrrole)/poly (vinyl alcohol) matrix

Energy Technology Data Exchange (ETDEWEB)

Idris, Sarada, E-mail: sarada@nuclearmalaysia.gov.my [Department of Radiation Technology, Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 (Malaysia); Bakar, Ahmad Ashrif A., E-mail: ashrif@ukm.edu.my [Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 (Malaysia); Thevy Ratnam, Chantara [Department of Radiation Technology, Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Kamaruddin, Nur Hasiba [Department of Electrical, Electronic and Systems Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 (Malaysia); Shaari, Sahbudin [Institute of Microengineering and Nanoelectronics, Universiti Kebangsaan Malaysia, Bangi, 43600 (Malaysia)

2017-04-01

Graphical abstract: The illustration of pyrrole polymerization, PVA crosslinking and immobilization of GOx onto polymer matrix. - Highlights: • Immobilization of glucose oxidase onto polymer matrices by gamma irradiation is proposed. • Crosslinking and grafting of polymers implies the immobilization reaction. • The mechanisms relies on gamma irradiation doses. • A simple single step process of polymerization, cross linking and immobilization by mean of gamma irradiation as was shown in Graphical abstract. - Abstract: This paper describes the immobilization of glucose oxidase, GOx onto polymer matrix comprising of poly(pyrrole), PPy and poly(vinyl alcohol), PVA using gamma irradiation technique. Py/PVA-GOx film was prepared by spreading PVA:GOx, 1:1 solution onto dried pyrrole film and exposed to gamma irradiation from cobalt 60 source at doses ranging from 0 to 60 kGy. The films were subjected to structural and morphological analyses by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Field emission scanning electron microscope (FESEM) and Atomic-force microscopy (AFM) techniques. Similar studies were also made on pristine pyrrole film which served as control. The SEM and FTIR spectra of Py/PVA-GOx film revealed that pyrrole has been successfully polymerized through irradiation-induced reactions. The results on the morphological properties of the samples characterize using FESEM, SEM and AFM further confirmed the occurrence of radiation-induced modification of Py/PVA-GOx film. The FTIR spectra showed the existence of intermolecular interaction between polymer matrix and GOx indicating that GOx had been successfully immobilized onto Ppy/PVA matrix by radiation-induced reactions. Results revealed that radiation induced reactions such as polymerization of pyrrole, crosslinking of PVA, grafting between the adjacent PVA and pyrrole molecules as well as immobilization of GOx onto Ppy

Influence of gamma irradiation on polymerization of pyrrole and glucose oxidase immobilization onto poly (pyrrole)/poly (vinyl alcohol) matrix

International Nuclear Information System (INIS)

Idris, Sarada; Bakar, Ahmad Ashrif A.; Thevy Ratnam, Chantara; Kamaruddin, Nur Hasiba; Shaari, Sahbudin

2017-01-01

Graphical abstract: The illustration of pyrrole polymerization, PVA crosslinking and immobilization of GOx onto polymer matrix. - Highlights: • Immobilization of glucose oxidase onto polymer matrices by gamma irradiation is proposed. • Crosslinking and grafting of polymers implies the immobilization reaction. • The mechanisms relies on gamma irradiation doses. • A simple single step process of polymerization, cross linking and immobilization by mean of gamma irradiation as was shown in Graphical abstract. - Abstract: This paper describes the immobilization of glucose oxidase, GOx onto polymer matrix comprising of poly(pyrrole), PPy and poly(vinyl alcohol), PVA using gamma irradiation technique. Py/PVA-GOx film was prepared by spreading PVA:GOx, 1:1 solution onto dried pyrrole film and exposed to gamma irradiation from cobalt 60 source at doses ranging from 0 to 60 kGy. The films were subjected to structural and morphological analyses by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Field emission scanning electron microscope (FESEM) and Atomic-force microscopy (AFM) techniques. Similar studies were also made on pristine pyrrole film which served as control. The SEM and FTIR spectra of Py/PVA-GOx film revealed that pyrrole has been successfully polymerized through irradiation-induced reactions. The results on the morphological properties of the samples characterize using FESEM, SEM and AFM further confirmed the occurrence of radiation-induced modification of Py/PVA-GOx film. The FTIR spectra showed the existence of intermolecular interaction between polymer matrix and GOx indicating that GOx had been successfully immobilized onto Ppy/PVA matrix by radiation-induced reactions. Results revealed that radiation induced reactions such as polymerization of pyrrole, crosslinking of PVA, grafting between the adjacent PVA and pyrrole molecules as well as immobilization of GOx onto Ppy

The discovery and the structural basis of an imidazo[4,5-b]pyridine-based p21-activated kinase 4 inhibitor.

Science.gov (United States)

Park, Jeung Kuk; Kim, Sunmin; Han, Yu Jin; Kim, Seong Hwan; Kang, Nam Sook; Lee, Hyuk; Park, SangYoun

2016-06-01

p21-Activated kinases (PAKs) which belong to the family of ste20 serine/threonine protein kinases regulate cytoskeletal reorganization, cell motility, cell proliferation, and oncogenic transformation which are all related to the cellular functions during cancer induction and metastasis. The fact that PAK mutations are detected in multiple tumor tissues makes PAKs a novel therapeutic drug target. In this study, an imidazo[4,5-b]pyridine-based PAK4 inhibitor, KY-04045 (6-Bromo-2-(3-isopropyl-1-methyl-1H-pyrazol-4-yl)-1H-imidazo[4,5-b]pyridine), was discovered using a virtual site-directed fragment-based drug design and was validated using an inhibition assay. Although PAK4 affinity to KY-04045 seems much weaker than that of the reported PAK4 inhibitors, the location of KY-04045 is clearly defined in the structure of PAK4 co-crystallized with KY-04045. The crystal structure illustrates that the pyrazole and imidazopyridine rings of KY-04045 are sufficient for mediating PAK4 hinge loop interaction. Hence, we believe that KY-04045 can be exploited as a basic building block in designing novel imidazo[4,5-b]pyridine-based PAK4 inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reactivity of vinyl ethers and vinyl ribosides in UV-initiated free radical copolymerization with acceptor monomers.

Science.gov (United States)

Pichavant, Loic; Guillermain, Céline; Coqueret, Xavier

2010-09-13

The reactivity of various vinyl ethers and vinyloxy derivatives of ribose in the presence of diethyl fumarate or diethyl maleate was investigated for evaluating the potential of donor-acceptor-type copolymerization applied to unsaturated monomers derived from renewable feedstock. The photochemically induced polymerization of model monomer blends in the bulk state was monitored by infrared spectroscopy. The method allowed us to examine the influence of monomer pair structure on the kinetic profiles. The simultaneous consumption of both monomers was observed, supporting an alternating copolymerization mechanism. A lower reactivity of the blends containing maleates compared with fumarates was confirmed. The obtained kinetic data revealed a general correlation between the initial polymerization rate and the Hansen parameter δ(H) associated with the H-bonding aptitude of the donor monomer.

Radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate in an engineering flow system

International Nuclear Information System (INIS)

Tsai, J.T.; Stahel, E.P.; Stannett, V.T.

1979-01-01

A flow reactor system was used to study the radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate. The emulsion was recirculated from a stirred vessel through transfer lines to a tubular reactor located within a high-intensity Co-60 source. The effects of physical chemical variables such as soap concentration, phase ratio, reaction temperature and residence time distribution on the molecular weight properties were investigated. The rate of copolymerization was found to be proportional to the 0.17 power of the soap concentration. Variation of the monomer-water ratio produced no significant change in rate. The rate increased with an increase in temperature over the range 5 to 50 0 C, while the average molecular weights of the copolymer increased with decreasing polymerization temperature. The molecular weight distribution in this engineering system was found to be essentially similar to those produced in a batch system

A state-of-the-art plasma polymerization coater for ICF targets

International Nuclear Information System (INIS)

Devine, G.; Letts, S.; Cook, R.; Brusasco, R.

1992-01-01

Increasingly stringent demands on the characteristics of plasma polymer coatings for use in Inertial Confinement Fusion (ICF) experiments have created a need for a plasma Polymerization coating system with the capability of producing a wide variety of different types of coatings as well as one that can be used to do fundamental investigations of the process conditions leading to desirable films. We report on the construction and use of just such a coating instrument. We have recognized the usefulness of computer assisted process monitoring and control, currently being developed by the semiconductor industry, in designing our own, State-of-the-art plasma polymerization device. Our system is fully computer interfaced to provide the user with the capability of collecting system parameter data over the length of the deposition experiment. The system is also designed to allow for any degree of computer control of the deposition process in the future

Water-stable diblock polystyrene-block-poly(2-vinyl pyridine) and diblock polystyrene-block-poly(methyl methacrylate) cylindrical patterned surfaces inhibit settlement of zoospores of the green alga Ulva.

Science.gov (United States)

Grozea, Claudia M; Gunari, Nikhil; Finlay, John A; Grozea, Daniel; Callow, Maureen E; Callow, James A; Lu, Zheng-Hong; Walker, Gilbert C

2009-04-13

Nanopatterned surfaces with hydrophobic and hydrophilic domains were produced using the diblock copolymer polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA). The PS-b-P2VP diblock copolymer, mixed with the cross-linker benzophenone and spin-coated onto silicon wafers, showed self-assembled cylindrical structures, which were retained after UV treatment for cross-linking. The thin films displayed cylindrical domains after immersion in water. This study shows that pattern retention in water is possible for a long period of time, at least for two weeks in pure water and three weeks in artificial seawater. The PS-b-PMMA diblock showed self-assembled cylindrical structures. PS-b-P2VP and PS-b-PMMA cylindrical patterned surfaces showed reduced settlement of zoospores of the green alga Ulva compared to unpatterned surfaces. The copolymers were investigated using atomic force microscopy and X-ray photoelectron spectroscopy.

3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

Science.gov (United States)

Ranjith, S.; SubbiahPandi, A.; Suresh, A. D.; Pitchumani, K.

2011-01-01

In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]. PMID:21837144

Thin plasma-polymerized layers of hexamethyldisiloxane for humidity sensor development

International Nuclear Information System (INIS)

Guermat, N.; Bellel, A.; Sahli, S.; Segui, Y.; Raynaud, P.

2009-01-01

The response of resistive-type sensors based on thin hexamethyldisiloxane layers to relative humidity (RH) was evaluated. Humidity sensitive layers were plasma polymerized at low frequency glow discharge using a capacitively coupled parallel plate reactor. The sensor design comprises the absorbing layer deposited on clean glass substrate with comb-shape aluminum electrodes (interdigitated structure). The change in electrical impedance of the sensing film was monitored as the device was exposed to humidity. The variation of the plasma-polymerization parameters resulted in different humidity sensing properties which could be correlated to the results of Fourier transform infrared spectroscopy (FTIR). The deposited films exhibited a detectable response to RH ranging from 30 to 95% with low hysteresis, good reproducibility and stability in long-term use. Films with a greater thickness showed a significant decrease in the humidity sensing capability. FTIR analysis revealed the presence of SiH bonding groups, which are frequently linked to the film density. The increase in the plasma discharge power induced also a significant decrease in the diffusion process of water vapor inside the sensitive layer bulk.

N,N-Diethyl-4-[(E-(pyridin-3-yldiazenyl]aniline

Directory of Open Access Journals (Sweden)

Tatiana V. Timofeeva

2013-08-01

Full Text Available The molecule of the title compound, C15H18N4, adopts a trans conformation with respect to the diazo N=N bond. The dihedral angle between the benzene and pyridine rings in the molecule is 8.03 (5°. In the crystal, a weak C—H...π interaction arranges the molecules into a corrugated ribbon, with an antiparallel orientation of neighboring molecules propagating in the [100] direction.

Preparation of nucleoside-pyridine hybrids and pyridine attached acylureas from an unexpected uracil ring-opening and pyridine ring-forming sequence

Institute of Scientific and Technical Information of China (English)

Xue Sen Fan; Xia Wang; Xin Ying Zhang; Dong Feng; Ying Ying Qu

2009-01-01

Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids (4) or pyridine attached acylureas (5) were selectively and efficiently prepared from the reaction of 2'-deoxyuridin-5-yl-methylene malonortitrile (1), malononitrile (2) and thiophenol (3) or from an unexpected uracil ring-opening and pyridine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.

Plasma-grafting polymerization on carbon fibers and its effect on their composite properties

Science.gov (United States)

Zhang, Huanxia; Li, Wei

2015-11-01

Interfacial adhesion between matrix and fibers plays a crucial role in controlling the performance of composites. Carbon fibers have the major constraint of chemical interness and hence have limited adhesion with the matrix. Surface treatment of fibers is the best solution to this problem. In this work, carbon fibers were activated by plasma and grafting polymerization. The grafting ratio of polymerization was obtained by acid-base titration. The chemical and physical changes induced by the treatments on carbon fiber surface was examined using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The interfacial adhesion of CF/EP (carbon fiber/epoxy) composites were analyzed by a single fiber composite (SFC) for filament fragmentation test. Experimental results show that the grafting rate was not only the function of the plasma-treat time but also the concentration of the grafting polymerization. The oxygen-containing groups (such as Csbnd O, Cdbnd O, and Osbnd Cdbnd O) and the interfacial shear strength (IFSS) of the plasma-grafting carbon fiber increased more significantly than the carbon fiber without plasma treatment grafted with MAH. This demonstrates that the surfaces of the carbon fiber samples are more active, hydrophilic, and rough after plasma-grafting treatments using a DBD operating in ambient argon mixture with oxygen. With DBD (dielectric barrier discharges) operating in ambient argon mixture with oxygen, the more active, hydrophilic, and rough surface was obtained by the plasma-grafting treatments.

In vivo characterization of the novel imidazopyridine BYK191023 [2-[2-(4-methoxy-pyridin-2-yl)-ethyl]-3H-imidazo[4,5-b]pyridine], a potent and highly selective inhibitor of inducible nitric-oxide synthase.

Science.gov (United States)

Lehner, Martin D; Marx, Degenhard; Boer, Rainer; Strub, Andreas; Hesslinger, Christian; Eltze, Manfrid; Ulrich, Wolf-Rüdiger; Schwoebel, Frank; Schermuly, Ralph Theo; Barsig, Johannes

2006-04-01

Excessive release of nitric oxide from inducible nitric-oxide synthase (iNOS) has been postulated to contribute to pathology in a number of inflammatory diseases. We recently identified imidazopyridine derivatives as a novel class of potent nitricoxide synthase inhibitors with high selectivity for the inducible isoform. In the present study, we tested the in vivo potency of BYK191023 [2-[2-(4-methoxy-pyridin-2-yl)-ethyl]-3H-imidazo-[4,5-b]pyridine], a selected member of this inhibitor class, in three different rat models of lipopolysaccharide-induced systemic inflammation. Delayed administration of BYK191023 dose-dependently suppressed the lipopolysaccharide-induced increase in plasma nitrate/nitrite (NO(x)) levels with an ED(50) of 14.9 micromol/kg/h. In a model of systemic hypotension following high-dose lipopolysaccharide challenge, curative administration of BYK191023 at a dose that inhibited 83% of the NO(x) increase completely prevented the gradual decrease in mean arterial blood pressure observed in vehicle-treated control animals. The vasopressor effect was specific for endotoxemic animals since BYK191023 did not affect blood pressure in saline-challenged controls. In addition, in a model of lipopolysaccharide-induced vascular hyporesponsiveness, BYK191023 infusion partially restored normal blood pressure responses to norepinephrine and sodium nitroprusside via an l-arginine competitive mechanism. Taken together, BYK191023 is a member of a novel class of highly isoform-selective iNOS inhibitors with promising in vivo activity suitable for mechanistic studies on the role of selective iNOS inhibition as well as clinical development.

Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

Science.gov (United States)

Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

1974-01-01

Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.

Science.gov (United States)

Reis, Rackel; Dumée, Ludovic F; He, Li; She, Fenghua; Orbell, John D; Winther-Jensen, Bjorn; Duke, Mikel C

2015-07-15

Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.

Graft copolymerization of styrene onto poly(vinyl alcohol) initiated by potassium diperiodatocuprate (III)

International Nuclear Information System (INIS)

Bai, L.; Wang, Ch.; Jin, J.; Liu, Y.

2009-01-01

The graft copolymerization of styrene onto poly(vinyl alcohol) is studied by using a novel redox system of potassium diperiodatocuprate-poly(vinyl alcohol) (Cu(III)poly(vinyl alcohol) in alkaline medium. Cu(III)-poly(vinyl alcohol) redox pair is an efficient initiator for this graft copolymerization which is proved by high graft efficiency (>97%) and high percentage of graft (>300%). Reaction conditions (monomer-to-poly(vinyl alcohol) weight ratio, initiator concentration, p H, time and temperature) affect the graft parameters which have been investigated systematically. The optimum reaction conditions are found as St/poly(vinyl alcohol) = 5.4; [Cu(III)] = 1*10 -2 M; p H = 12.7; temperature = 50 d eg C ; time = 3.5 h. Further, the equation of the overall polymerization rate can be written as follows: R p = k C 1.9 (St) C 1.7 (Cu(III)). The overall activation energy was calculated to be 42.0 kJ/mol based on the experimental data of the relations between R p and C(St); R p and C(Cu(III)); and R p and temperature. A mechanism is proposed to explain the formation of radicals and the initiation. The structure of the graft copolymers is confirmed by Fourier transfer infrared spectroscopy. Some peaks were compared with poly(vinyl alcohol) at 3080.34-3001.79 cm -1 (=C-H stretching in the phenyl ring), 1600.34-1450.95 cm -1 (C=C stretching in the phenyl ring), 755.17 cm -1 and 698.64 cm -1 (=C-H out-off-plane bending in phenyl ring) which are considered to belong to the characteristic absorption bands of phenyl group of polystyrene. Therefore it proves that the graft copolymer is composed of poly(vinyl alcohol) and polystyrene. thermal gravimetric analysis thermo grams of poly(vinyl alcohol) and poly(vinyl alcohol)-graft-polystyrene are investigated as well. As it is shown the initial decomposition temperature of poly(vinyl alcohol)-g-polystyrene(377.3 d eg C ) is much higher than that of poly(vinyl alcohol) (241.8 d eg C ), which indicates that the thermal stability of the

Polymerization of Methyl Methacrylate Catalyzed by Co(II), Cu(II), and Zn(II) Complexes Bearing N-Methyl-N-((pyridin-2-yl)methyl) cyclohexanamine

Energy Technology Data Exchange (ETDEWEB)

Ahn, Seoung Hyun; Lee, Hyosun [Kyungpook National University, Daegu (Korea, Republic of); Shin, Jongwon [POSTECH, Pohang (Korea, Republic of); Nayab, Saira [Shaheed Benazir Bhutto University, Sheringal (Pakistan)

2016-05-15

We demonstrated the synthesis and characterization of Co(II), Cu(II), and Zn(II) complexes ligated to N-methyl-N-((pyridin-2-yl)methyl)cyclohexanamine. The complex [Co(nmpc)Cl{sub 2}] in the presence of MMAO showed the highest catalytic activity for MMA polymerization at 60 °C compared with its Zn(II) and Cu(II) analogs. The metal center showed an obvious influence on the catalytic activity, although this appeared to have no effect on the stereo-regularity of the resultant PMMA. X-ray diffraction analysis revealed that [Co(nmpc)Cl{sub 2}] and [Zn(nmpc)Cl{sub 2}] crystallized in the monoclinic system with space group P2{sub 1}/c and existed as monomeric and solvent-free complexes.

Novel Alkyd-Type Coating Resins Produced Using Cationic Polymerization [PowerPoint

Energy Technology Data Exchange (ETDEWEB)

Chisholm, Bret; Kalita, Harjyoti; Alam, Samim; Jayasooriyamu, Anurad; Fernando, Shashi; Samanata, Satyabrata; Bahr, James; Selvakumar, Sermadurai; Sibi, Mukund; Vold, Jessica; Ulven, Chad

2014-04-07

Novel, partially bio-based poly(vinyl ether) copolymers derived from soybean oil and cyclohexyl vinyl ether (CHVE) were produced by cationic polymerization and investigated for application as alkyd-type surface coatings. Compared to conventional alkyd resins, which are produced by high temperature melt condensation polymerization, the poly(vinyl ether)s provide several advantages. These advantages include miler, more energy efficient polymer synthesis, elimination of issues associated with gelation during polymer synthesis, production of polymers with well-defined composition and relatively narrow molecular weight distribution, and elimination of film formation and physical property issues associated with entrained monomers, dimers, trimmers, etc. The results of the studied showed that the thermal, mechanical, and physical properties of the coatings produced from these novel polymers varied considerable as a function of polymer composition and cure temperature. Overall, the results suggest a good potential for these novel copolymers to be used for coatings cured by autoxidation.

Crystal structure of [tris(pyridin-2-ylmethyl)amine-κ4N]copper(II) bromide

OpenAIRE

Emma C. Bridgman; Megan M. Doherty; Kaleigh A. Ellis; Elizabeth A. Homer; Taylor N. Lashbrook; Margaret E. Mraz; Gina C. Pernesky; Emma M. Vreeke; Kayode D. Oshin; Allen G. Oliver

2016-01-01

In the asymmetric unit of the title compound, [CuBr(C18H18N4)]Br, there are three crystallographically independent cations. One of the cations exhibits positional disorder of the pyridin-2-yl?methyl groups over two sets of sites with refined occupancies of 0.672?(8) and 0.328?(8). The outer-sphere bromine counter-ion is severely disordered over multiple sites. In each cation, the CuII ion is coordinated by the four N atoms of the tris?(pyridin-2-ylmeth?yl)amine ligand and one bromine and adop...

Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

Directory of Open Access Journals (Sweden)

Barbara Palka

2014-07-01

Full Text Available A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a one-pot multicomponent procedure. Oximes derived from (intermediate 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F were undertaken with all obtained products.

Influence of gamma irradiation on polymerization of pyrrole and glucose oxidase immobilization onto poly (pyrrole)/poly (vinyl alcohol) matrix

Science.gov (United States)

Idris, Sarada; A. Bakar, Ahmad Ashrif; Thevy Ratnam, Chantara; Kamaruddin, Nur Hasiba; Shaari, Sahbudin

2017-04-01

This paper describes the immobilization of glucose oxidase, GOx onto polymer matrix comprising of poly(pyrrole), PPy and poly(vinyl alcohol), PVA using gamma irradiation technique. Py/PVA-GOx film was prepared by spreading PVA:GOx, 1:1 solution onto dried pyrrole film and exposed to gamma irradiation from cobalt 60 source at doses ranging from 0 to 60 kGy. The films were subjected to structural and morphological analyses by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Field emission scanning electron microscope (FESEM) and Atomic-force microscopy (AFM) techniques. Similar studies were also made on pristine pyrrole film which served as control. The SEM and FTIR spectra of Py/PVA-GOx film revealed that pyrrole has been successfully polymerized through irradiation-induced reactions. The results on the morphological properties of the samples characterize using FESEM, SEM and AFM further confirmed the occurrence of radiation-induced modification of Py/PVA-GOx film. The FTIR spectra showed the existence of intermolecular interaction between polymer matrix and GOx indicating that GOx had been successfully immobilized onto Ppy/PVA matrix by radiation-induced reactions. Results revealed that radiation induced reactions such as polymerization of pyrrole, crosslinking of PVA, grafting between the adjacent PVA and pyrrole molecules as well as immobilization of GOx onto Ppy/PVA matrix occurred simultaneously upon gamma irradiation. The optimum dose for GOx immobilization in the polymer matrix found to be 40 kGy. Therefore it is clear that this irradiation technique offered a simple single process to produce Py/PVA-GOx film without additional crosslinking and polymerization agents.

Plasma etching of electrospun polymeric nanofibres

Energy Technology Data Exchange (ETDEWEB)

Verdonck, Patrick [LSI-PSI-EPUSP, Av. Prof. Luciano Gualberto trav 3, 158, 05508-900 Sao Paulo, SP (Brazil)]. E-mail: verdonck@imec.be; Braga Caliope, Priscila [LSI-PSI-EPUSP, Av. Prof. Luciano Gualberto trav 3, 158, 05508-900 Sao Paulo, SP (Brazil); Moral Hernandez, Emilio del [LSI-PSI-EPUSP, Av. Prof. Luciano Gualberto trav 3, 158, 05508-900 Sao Paulo, SP (Brazil); Silva, Ana Neilde R. da [LSI-PSI-EPUSP, Av. Prof. Luciano Gualberto trav 3, 158, 05508-900 Sao Paulo, SP (Brazil); FATEC-SP, Pca Fernando Prestes, 30 Sao Paulo, SP (Brazil)

2006-10-25

Electrospun polymeric nanofibres have several applications because of their high surface area to volume and high length to diameter ratios. This paper investigates the influence of plasma etching on these fibres and the etching mechanisms. For the characterization, SEM analysis was performed to determine the forms and shapes of the fibres and SEM photos were analysed by the technique of mathematical morphology, in order to determine the area on the sample occupied by the fibres and the frequency distribution of the nanofibre diameters. The results showed that the oxygen plasma etches the nanofibres much faster when ion bombardment is present. The form of the fibres is not altered by the etching, indicating the possibility of transport of oxygen atoms over the fibre surface. The most frequent diameter, somewhat surprisingly, is not significantly dependent on the etching process, and remains of the order of 80 nm, indicating that fibres with smaller diameters are etched at high rates.

Liquid chromatography-tandem mass spectrometry analysis of 2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-b]pyridine in cooked meats.

Science.gov (United States)

Busquets, R; Puignou, L; Galceran, M T; Wakabayashi, K; Skog, K

2007-10-31

Several cooked meats such as beef (fried, coated-fried), pork (fried, coated-fried), and chicken (fried, griddled, coated-fried, roasted) were analyzed for the heterocyclic amine 2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5- b]pyridine (4'-OH-PhIP) not commonly determined in food and 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine (PhIP). The highest content of 4'-OH-PhIP was found in fried and griddled chicken breast, the concentration being 43.7 and 13.4 ng/g, respectively, whereas the corresponding PhIP concentrations were 19.2 and 5.8 ng/g. The estimated concentration of both pyridines in fried pork loin, in fried pork sausages, and in coated-fried chicken was below 2.5 ng/g. In the rest of the samples, 4'-OH-PhIP was not detected. The analyses were performed by solid-phase extraction and LC-MS/MS. The fragmentation of 4'-OH-PhIP in an ion trap mass analyzer was studied in order to provide information for the identification of 4'-OH-PhIP. Additionally, the effect of red wine marinades on the formation of 4'-OH-PhIP in fried chicken was examined, finding a notable reduction (69%) in the amine's occurrence.

Ugi-Smiles couplings of 4-substituted pyridine derivatives : a fast access to chloroquine analogues

NARCIS (Netherlands)

El Kaïm, Laurent; Grimaud, Laurence; Pravin, Patil; Patil, Pravin

2012-01-01

4-Hydroxy and mercapto pyridines were successfully tested in Ugi-Smiles couplings. Such multicomponent reactions applied to quinoline derivatives afford a very convenient and short synthesis of antimalarial analogues.

2-[1-(1-Naphthyl-1H-1,2,3-triazol-4-yl]pyridine

Directory of Open Access Journals (Sweden)

Ulrich S. Schubert

2009-05-01

Full Text Available In the crystal structure of the title compound, C17H12N4, the angle between the naphthalene and 1H-1,2,3-triazole ring systems is 71.02 (4° and that between the pyridine and triazole rings is 8.30 (9°.

catena-Poly[[[diaquabis(selenocyanato-κNiron(II]-μ-1,2-bis(pyridin-4-ylethane-κ2N:N′] 1,2-bis(pyridin-4-ylethane disolvate dihydrate

Directory of Open Access Journals (Sweden)

Susanne Wöhlert

2013-06-01

Full Text Available The title compound, {[Fe(NCSe2(C12H12N2(H2O2]·2C12H12N2·2H2O}n, was obtained by the reaction of iron(II sulfate heptahydrate and potassium selenocyanate with 1,2-bis(pyridin-4-ylethane (bpa in water. The FeII cation is coordinated by two N-bonded selenocyanate anions, two water molecules and two 1,2-bis(pyridin-4-ylethane (bpa ligands in a slightly distorted octahedral geometry. In addition, two non-coordinating bpa molecules and two water molecules are present. The FeII cation is located on a center of inversion while the coordinating bpa ligand is located on a twofold rotation axis. The FeII cations are linked by the bpa ligands into chains along the b-axis direction, which are further connected into layers perpedicular to the c axis by O—H...N and O—H...O hydrogen bonds to the non-coordinating bpa and the water molecules. The crystal studied was twinned by pseudo-merohedry (180° rotation along c*; contribution of the minor twin component 3.7%.

Design, synthesis and characterization of 1H-pyridin-4-yl-3,5 ...

Indian Academy of Sciences (India)

Keywords. 1H-pyridin-4-yl-3,5-disubstituted indazoles; Suzuki reaction; Akt kinase activity. 1. Introduction. In organic synthesis, Palladium-catalysed new carbon– carbon bond formation from aryl halides with organo boronic acids via Suzuki coupling reaction has been proved to be an important method. The 2010 Nobel.

Investigations in the field of solid state polymerization Pt. 38

International Nuclear Information System (INIS)

Hardy, Gy.; Cser, F.; Nyitrai, K.; Fedorova, N.

1980-01-01

The stuctural and radiation chemical data of vinyl monomers with long chain paraffinic or cholesteric side groups are critically reviewed. Based on their structural and polymerization kinetical characteristics the monomers may be classified into three groups. Oblique layers are favourable for homogeneous topotactic polymerization. This is characterized by a low activation energy and a radiochemical efficiency very similar to that measured in liquid state polymerization. The tilted layers are not favourable for homogeneous topotactic polymerization. Allyl monomers yield polymers with higher molecular weights in the layer structure than in liquid states. (author)

N-acetyltransferase-dependent activation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine: formation of 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo [4,5-b]pyridine, a possible biomarker for the reactive dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

DEFF Research Database (Denmark)

Frandsen, Henrik Lauritz; Alexander, J.

2000-01-01

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. PhIP is metabolically activated to the ultimate mutagenic metabolite by CYP P450-mediated N-hydroxylation followed by phase II esterification, Incubation of N...

Macroporous poly(vinyl alcohol) microspheres bearing phosphate groups as a new adsorbent for low-density lipoprotein apheresis

Energy Technology Data Exchange (ETDEWEB)

Wang Weichao; Xie Hui; Ou Lailiang; Wang Lianyong; Yu Yaoting; Kong Deling [Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071 (China); Sun Lisha, E-mail: wly@nankai.edu.c, E-mail: kongdeling@nankai.edu.c [General Hospital, Tianjin Medical University, Tianjin 300052 (China)

2009-12-15

A new low-density lipoprotein (LDL) adsorbent with phosphate groups as the ligand was prepared in this study. Macroporous poly(vinyl acetate-co-triallyl isocyanurate) microspheres were prepared using a free-radical suspension polymerization method. A hydrolysis reaction in sodium hydroxide/methanol changed the materials into poly(vinyl alcohol) (PVA) microspheres. Further reaction with phosphorus oxychloride in anhydrous DMF led to the LDL adsorbent PVA-phosphate microspheres. The preparation conditions such as reaction time, temperature and the amount of phosphorus oxychloride were optimized. The adsorption of plasma lipoproteins was examined by in vitro adsorption assays. The influence of adsorption time, plasma volume and ionic strength on the adsorption capacity was investigated. The circulation adsorption showed that the pathogenic lipoproteins in the plasma such as total cholesterol (TC), LDL and triglyceride (TG) could be removed markedly, in which the removal percentages were 42.9%, 45.0% and 44.74%, respectively. However, the reduction of high-density lipoprotein (HDL) and other normal plasma components was very slight. For in vivo experiment, rabbits were fed with high-cholesterol food to develop a hyperlipidemia model and treated by extracorporeal blood perfusion using the PVA-phosphate columns. Eight hyperlipidemia rabbits were treated with the PVA-phosphate adsorbent, and the removal of TC, LDL and TG was 45.03 +- 6.64%, 48.97 +- 9.92% and 35.42 +- 14.17%, respectively. The sterilization and storage tests showed that the adsorbent was chemically and functionally stable. It could be easily sterilized by a common method and stored for months without loss of adsorption capacity. Therefore, this new PVA-phosphate-based LDL adsorbent may have potential for application in LDL apheresis.

Macroporous poly(vinyl alcohol) microspheres bearing phosphate groups as a new adsorbent for low-density lipoprotein apheresis

International Nuclear Information System (INIS)

Wang Weichao; Xie Hui; Ou Lailiang; Wang Lianyong; Yu Yaoting; Kong Deling; Sun Lisha

2009-01-01

A new low-density lipoprotein (LDL) adsorbent with phosphate groups as the ligand was prepared in this study. Macroporous poly(vinyl acetate-co-triallyl isocyanurate) microspheres were prepared using a free-radical suspension polymerization method. A hydrolysis reaction in sodium hydroxide/methanol changed the materials into poly(vinyl alcohol) (PVA) microspheres. Further reaction with phosphorus oxychloride in anhydrous DMF led to the LDL adsorbent PVA-phosphate microspheres. The preparation conditions such as reaction time, temperature and the amount of phosphorus oxychloride were optimized. The adsorption of plasma lipoproteins was examined by in vitro adsorption assays. The influence of adsorption time, plasma volume and ionic strength on the adsorption capacity was investigated. The circulation adsorption showed that the pathogenic lipoproteins in the plasma such as total cholesterol (TC), LDL and triglyceride (TG) could be removed markedly, in which the removal percentages were 42.9%, 45.0% and 44.74%, respectively. However, the reduction of high-density lipoprotein (HDL) and other normal plasma components was very slight. For in vivo experiment, rabbits were fed with high-cholesterol food to develop a hyperlipidemia model and treated by extracorporeal blood perfusion using the PVA-phosphate columns. Eight hyperlipidemia rabbits were treated with the PVA-phosphate adsorbent, and the removal of TC, LDL and TG was 45.03 ± 6.64%, 48.97 ± 9.92% and 35.42 ± 14.17%, respectively. The sterilization and storage tests showed that the adsorbent was chemically and functionally stable. It could be easily sterilized by a common method and stored for months without loss of adsorption capacity. Therefore, this new PVA-phosphate-based LDL adsorbent may have potential for application in LDL apheresis.

Radiosynthesis of 3-{l_brace}[4-(4-[{sup 18}F]fluorobenzyl)]piperazin-1-yl{r_brace}methyl-1H-pyrrolo[2,3-b]pyridine: A potential dopamine D{sub 4} receptor imaging agent

Energy Technology Data Exchange (ETDEWEB)

Haibin Tian; Duanzhi Yin; Junling Li; Lan Zhang; Cunfu Zhang; Yongxian Wang; Wei Zhou [Radiopharmaceutical Research Center, Shanghai Inst. of Nuclear Research, The Chinese Academy of Sciences, Shanghai, SH (China)

2003-07-01

The dopamine D{sub 4} receptor (D{sub 4}R) is expressed in low density in various extrastriatal brain regions. This receptor subtype is discussed in relation to the pathophysiology and treatment of schizophrenia but to date no selective positron emission tomography (PET) ligand is available to study its distribution in vivo. The 7-azaindole derivative 3-([4-(4-iodophenyl)piperazin-1-yl]-methyl)-1H-pyrrolo [2,3-b]pyridine (L-750,667) is a novel, high-affinity (K{sub i}=0.51nM) and selective D{sub 4}R ligand. L-750,667 analogue 3-[4-(4-[{sup 18}F]fluorobenzyl)]piperazin-1-yl methyl-1H-pyrrolo[2,3-b]-pyridine was prepared by reacting 3-(piperazin-1-yl)-methyl-1H-pyrrolo[2,3-b]pyridine with 4-[ 18F]fluorobenzaldehyde, which was labeled with no carrier added [ 18F]fluoride. The radiochemical yield of 3-[4-(4-[{sup 18}F]fluorobenzyl)]piperazin-1-yl methyl-1H-pyrrolo[2,3-b]pyridine was 12.0% at end of synthesis (EOS), and the synthesis time was 73min. The labeled benzaldehydes may be useful precursors for the radiosyntheses of other complex radiotracers for PET.

Synthesis and structure of a ferric complex of 2,6-di(1H-pyrazol-3-yl)pyridine and its excellent performance in the redox-controlled living ring-opening polymerization of ε-caprolactone.

Science.gov (United States)

Fang, Yang-Yang; Gong, Wei-Jie; Shang, Xiu-Juan; Li, Hong-Xi; Gao, Jun; Lang, Jian-Ping

2014-06-14

The reaction of FeCl3 with a pincer ligand, 2,6-di(1H-pyrazol-3-yl)pyridine (bppyH2), produced a mononuclear Fe(III) complex [Fe(bppyH2)Cl3] (1), which could be reduced to the corresponding Fe(II) dichloride complex [Fe(bppyH2)Cl2] (2) by suitable reducing agents such as Cp2Co or Fe powder. 1 and 2 exhibited a reversible transformation from each other with appropriate redox reagents. 1 could be utilized as a pre-catalyst to initiate the ring-opening polymerization of ε-caprolactone in the presence of alcohol but did not work. The 1/alcohol system displayed characteristics of a well-controlled polymerization with the resulting poly(ε-caprolactone) having low molecular weight distributions, a linear tendency of molecular weight evolution with conversion, and polymer growth observed for the sequential additions of ε-caprolactone monomer to the polymerization reaction. The polymerization was completely turned off by the in situ reduction of the catalytic Fe center via Cp2Co and then turned back upon the addition of [Cp2Fe]PF6. The rate of polymerization was modified by switching in situ between the Fe(III) and Fe(II) species.

Investigation of the surface chemical and electronic states of pyridine-capped CdSe nanocrystal films after plasma treatments using H2, O2, and Ar gases

International Nuclear Information System (INIS)

Wang, Seok-Joo; Kim, Hyuncheol; Park, Hyung-Ho; Lee, Young-Su; Jeon, Hyeongtag; Chang, Ho Jung

2010-01-01

Surface chemical bonding and the electronic states of pyridine-capped CdSe nanocrystal films were evaluated using x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy before and after plasma treatments using H 2 , O 2 , and Ar gases from the viewpoint of studying the effects of surface capping organic molecules and surface oxidation. Surface capping organic molecules could be removed during the plasma treatment due to the chemical reactivity, ion energy transfer, and vacuum UV (VUV) of the plasma gases. With O 2 plasma treatment, surface capping organic molecules were effectively removed but substantial oxidation of CdSe occurred during the plasma treatment. The valence band maximum energy (E VBM ) of CdSe nanocrystal films mainly depends on the apparent size of pyridine-capped CdSe nanocrystals, which controls the interparticle distance, and also on the oxidation of CdSe nanocrystals. Cd-rich surface in O 2 and H 2 plasma treatments partially would compensate for the decrease in E VBM . After Ar plasma treatment, the smallest value of E VBM resulted from high VUV photon flux, short wavelength, and ion energy transfer. The surface bonding states of CdSe had a strong influence on the electronic structure with the efficient strip of capping molecules as well as different surface oxidations and surface capping molecule contents.

Synthesis and in-vivo evaluation of C-11 p-PVP-MEMA as a PET radioligand for imaging nicotinic receptors

International Nuclear Information System (INIS)

Paine, T.; Kassiou, M.; Dolle, F.; Langle, S.; Roger, G.; Lagnel-de Bruin, B.; Hinnen, F.; Valette, H.; Bottlaender, M.; Fulton, R.R.; Henderson, D.J.; Coster, M.J.; Kassiou, M.

2008-01-01

Within the class of (4-pyridinyl)vinyl-pyridines developed by Abbott laboratories as potent neuronal nicotinic acetylcholine receptor ligands, p-PVP-MEMA ({oro-5-((E)-2-pyridin-4-yl-vinyl) pyridin-3-yloxy]-1-methylethyl} is the lead compound of a novel series that do not display the traditional nicotinic-like pyrrole-ring but still possessing high sub-nanomolar affinity (K-i 0.077 nm-displacement of [H-3](-)cytisine from whole rat brain synaptic membranes). In the present study, p-PVP-MEMA and its nor-derivative ({oro-5-((E)-2-pyridin-4- yl-vinyl) pyridin-3-yloxy]-1-methylethyl} as precursor for labelling with the short-lived positron-emitter carbon-11 (T 1/2 = 20.4 min) were synthesized in 10 chemical steps from 2-hydroxy-5-nitropyridine and Boc-D-alanine. N-Alkylation of nor-p-PVP-MEMA with [C-11] methyl iodide afforded [C-11]p-PVP-MEMA (≥ 98% radiochemically pure, specific activity of 86.4 GBq μ mol -1 ) in 2% (non-decay corrected and non-optimized) radiochemical yield, in 34 min (including HPLC purification and formulation). Preliminary positron emission tomography PET) results obtained in a Papio hamadryas baboon showed that [C-11] p-PVP-MEMA is not a suitable PET-radioligand. (authors)

Polyethylene Oxide Films Polymerized by Radio Frequency Plasma-Enhanced Chemical Vapour Phase Deposition and Its Adsorption Behaviour of Platelet-Rich Plasma

International Nuclear Information System (INIS)

Wen-Juan, Hu; Fen-Yan, Xie; Qiang, Chen; Jing, Weng

2008-01-01

We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C-O-C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C-O-C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films

Polyethylene Oxide Films Polymerized by Radio Frequency Plasma-Enhanced Chemical Vapour Phase Deposition and Its Adsorption Behaviour of Platelet-Rich Plasma

Science.gov (United States)

Hu, Wen-Juan; Xie, Fen-Yan; Chen, Qiang; Weng, Jing

2008-10-01

We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C-O-C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C-O-C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films.

Radiation chemical grafting of vinyl acetate and styrene on nitrocellulose

International Nuclear Information System (INIS)

Chapiro, A.; Foex, M.; Jendrychowska-Bonamour, A.M.

1977-01-01

Vinyl acetate and styrene were grafted onto nitrocellulose using the direct radiation grafting technique with 500 and 3000 Ci 60 Co γ sources. For vinyl acetate, the reaction proceeds homogeneously. The kinetics are dominated by degradative chain transfer to the nitrocellulose. The polymerization of vinyl acetate was examined in the presence of isoamyl nitrate, a model for nitrocellulose; the transfer constant was determined and the results are treated semi-quantitatively. For styrene, grafting occurs in a swollen film irradiated in the presence of excess monomer. The diffusion of styrene into nitrocellulose is extremely slow; methanol was added to the reaction mixture to favour diffusion which was found to obey Fick's law. The diffusion constant and activation energy of diffusion are evaluated. The grafting kinetics are controlled by monomer diffusion, accounting for the increase of dose-rate exponent with temperature. A spontaneous grafting process occurs in the absence of irradiation. It is initiated by macroradicals arising from thermal decomposition of nitrocellulose. (author)

13C Kinetic isotopic effect of polymerization on monomers with multiple bond

International Nuclear Information System (INIS)

Berman, E.L.; Polyakov, V.B.; Makovetskij, K.L.; Golenko, T.G.; Galimov, Eh.M.; AN SSSR, Moscow. Inst. Organicheskoj Khimii; AN SSSR, Moscow. Inst. Geokhimii i Analiticheskoj Khimii)

1988-01-01

13 C kinetic isotopic effect (KIE) of anionic and radical polymerization and metathesis reaction of monomers with multiple bonds are studied and correlation between the found KIE values of polymerization and the structure of transition state is established. 13 C KIE of polymerization reactions are investigated using monomers with natural content of the isotope. Polymerization was carried out using high-vacuum equipment: radical polymerization of methyl acrylate (MA) and vinyl acetate in benzene solution under the effect of benzoyl peroxide (60 deg C); anionic polymerization of MA, initiated by potassium butyl cellosolvolate, was realized in mass at 25 deg C; cyclopentene metathesis reaction was conducted in benzene under the effect of initiating system WCl 6 - (C 3 H 5 ) 2 Si(CH 3 ) 2 at -30 deg C; phenylacetylene polymers were prepared by polymerization in benzene solution at 20 deg C under the effect of WCl 6 . It is ascertained that 13 C KIE of radical and anionic polymerization of olefins and cycloolefin metathesis constitutes 2.0 -2.4%. Polymerization of compound with ternary bond is accompanied by a lower value of 13 C KIE (<1%), which is explained by double bond of reacting bond in transition state

4-Benzyl-6-bromo-2-(4-methoxyphenyl-4H-imidazo[4,5-b]pyridine monohydrate

Directory of Open Access Journals (Sweden)

Y. Ouzidan

2010-04-01

Full Text Available The imidazopyridine fused ring in the title compound, C20H16BrN3O·H2O, is coplanar with the aromatic ring at the 2-position [dihedral angle = 5.2 (1°]. In the five-membered imidazo portion, the C—N bond whose C atom is also connected to the pyridine N atom has predominantly double-bond character [1.334 (2 Å] whereas the C—N bond whose atom is connected to the pyridine C atom has predominantly single-bond character [1.371 (2 Å]. The water molecule engages in hydrogen bonding with the latter N atom; it is also connected to a symmetry-related water molecule, generating a linear chain structure.

Ugi-Smiles couplings of 4-substituted pyridine derivatives: a fast access to chloroquine analogues.

Science.gov (United States)

El Kaïm, Laurent; Grimaud, Laurence; Pravin, Patil

2012-01-20

4-Hydroxy and mercapto pyridines were successfully tested in Ugi-Smiles couplings. Such multicomponent reactions applied to quinoline derivatives afford a very convenient and short synthesis of antimalarial analogues. © 2011 American Chemical Society

Direct Alkynylation of 3H-Imidazo[4,5-b]pyridines Using gem-Dibromoalkenes as Alkynes Source.

Science.gov (United States)

Aziz, Jessy; Baladi, Tom; Piguel, Sandrine

2016-05-20

C2 direct alkynylation of 3H-imidazo[4,5-b]pyridine derivatives is explored for the first time. Stable and readily available 1,1-dibromo-1-alkenes, electrophilic alkyne precursors, are used as coupling partners. The simple reaction conditions include an inexpensive copper catalyst (CuBr·SMe2 or Cu(OAc)2), a phosphine ligand (DPEphos) and a base (LiOtBu) in 1,4-dioxane at 120 °C. This C-H alkynylation method revealed to be compatible with a variety of substitutions on both coupling partners: heteroarenes and gem-dibromoalkenes. This protocol allows the straightforward synthesis of various 2-alkynyl-3H-imidazo[4,5-b]pyridines, a valuable scaffold in drug design.

21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2...

Antioxidant Microemulsion-based Ethylene Vinyl Acetate Film Containing Mangiferin and Surfactants

Directory of Open Access Journals (Sweden)

Boonnattakorn Rungkan

2016-01-01

Full Text Available Mangiferin, a natural antioxidant additive, was incorporated into an ethylene vinyl acetate copolymer (EVA containing 18% vinyl acetate (VA using the emulsion solvent evaporation technique. Sorbitan ester (Span®20 and polymeric surfactant (Pluronic®P−123 were compared. Mangiferin was finely dispersed in the suspension with the addition of surfactants studied. Span®20 was chosen as the surfactant for film preparation in the next step due to the dispersing and film forming properties. Effects of vinyl acetate (VA contents on the film properties were investigated. The EVA films with 12% VA had the highest tensile strength and oxygen barrier, followed by 18, 25 and 40% VA, respectively. Addition of Span®20 had only a slight effect on mechanical and barrier properties of the films, but markedly increased the release of mangiferin from the EVA matrices except in the 40% VA films. The maximum concentrations of mangiferin released from the 40, 25, 18 and 12% VA films into 95% ethanol were 83.30, 66.84, 51.77 and 34.57 μg·mL−11, respectively. The release concentrations from the 40 and 25% VA films was 2.4 and 1.9 folds of that from the 12% VA film, respectively. The antioxidant activity of the EVA films containing mangiferin and Span®20 was 80% radical-scavenging capacity (RSC for the 40 and 25% VA and 60% RSC for the 18 and 12% VA. The release of mangiferin from the EVA matrices may be controlled by appropriate selection of the surfactants and vinyl acetate contents.

Laser induced augmentation of silver nanospheres to nanowires in ethanol fostered by Poly Vinyl Pyrrolidone

Energy Technology Data Exchange (ETDEWEB)

Sebastian, Suneetha, E-mail: sunikutty@gmail.com; Linslal, C.L.; Vallabhan, C.P.G.; Nampoori, V.P.N.; Radhakrishnan, P.; Kailasnath, M.

2014-11-30

Highlights: • Silver nanospheres are synthesised in ethanol containing Poly Vinyl Pyrrolidone which acts as a polymeric capping agent to nanoparticles thus improving its stability. • Laser irradiation onto the colloidal solution of silver nanoparticles produced well defined nanowires through ripening mechanism promoted by Poly Vinyl Pyrrolidone. • Nanowires so formed are having an average length of 8.7 μm and width of 160 nm. - Abstract: Stable uniform silver nanospheres having an average diameter of 45 nm are synthesised in ethanol containing Poly Vinyl Pyrrolidone using Laser Ablation in Liquid technique. Further irradiation of the nanocolloidal solution by focussed laser beam produced stable well defined silver nanowires through ripening mechanism fostered by the presence of Poly Vinyl Pyrrolidone. Confirmation of the mechanism is obtained from Transmission Electron Microscopic images of the nanocolloidal solution irradiated for different time durations.

Interfacing polymeric scaffolds with primary pancreatic ductal adenocarcinoma cells to develop 3D cancer models

NARCIS (Netherlands)

Ricci, C.; Mota, C.M.; Moscato, S.; D' Alessandro, D.; Ugel, S.; Sartoris, S.; Bronte, V.; Boggi, U.; Campani, D.; Funel, N.; Moroni, Lorenzo; Danti, S.

2014-01-01

We analyzed the interactions between human primary cells from pancreatic ductal adenocarcinoma (PDAC) and polymeric scaffolds to develop 3D cancer models useful for mimicking the biology of this tumor. Three scaffold types based on two biocompatible polymeric formulations, such as poly(vinyl

Synthesis of mesoporous hollow silica nanospheres using polymeric micelles as template and their application as a drug-delivery carrier.

Science.gov (United States)

Sasidharan, Manickam; Zenibana, Haruna; Nandi, Mahasweta; Bhaumik, Asim; Nakashima, Kenichi

2013-10-07

Mesoporous hollow silica nanospheres with uniform particle sizes of 31-33 nm have been successfully synthesized by cocondensation of tetramethoxysilane (TMOS) and alkyltrimethoxysilanes [RSi(OR)3], where the latter also acts as a porogen. ABC triblock copolymer micelles of poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-PVP-PEO) with a core-shell-corona architecture have been employed as a soft template at pH 4. The cationic shell block with 2-vinyl pyridine groups facilitates the condensation of silica precursors under the sol-gel reaction conditions. Phenyltrimethoxysilane, octyltriethoxysilane, and octadecyltriethoxysilanes were used as porogens for generating mesopores in the shell matrix of hollow silica and the octadecyl precursor produced the largest mesopore among the different porogens, of dimension ca. 4.1 nm. The mesoporous hollow particles were thoroughly characterized by small-angle X-ray diffraction (SXRD), thermal (TG/DTA) and nitrogen sorption analyses, infra-red (FTIR) and nuclear magnetic resonance ((13)C-CP MAS NMR and (29)Si MAS NMR) spectroscopies, and transmission electron microscopy (TEM). The mesoporous hollow silica nanospheres have been investigated for drug-delivery application by an in vitro method using ibuprofen as a model drug. The hollow silica nanospheres exhibited higher storage capacity than the well-known mesoporous silica MCM-41. Propylamine functionalized hollow particles show a more sustained release pattern than their unfunctionalized counterparts, suggesting a huge potential of hollow silica nanospheres in the controlled delivery of small drug molecules.

THE KINETICS OF METHYL METHACRYLATE POLYMERIZATION INITIATED BY THE VOLATILE PRODUCTS OF A METHYL METHACRYLATE PLASMA

Institute of Scientific and Technical Information of China (English)

杨梅林; 马於光; 郑莹光; 沈家骢

1990-01-01

It is found that the volatile products of methyl methacrylate plasma can very actively initiate the polymerization of the monomer to produce ultrahigh molecular weight polymers. This polymerization of MMA occurs by a livlng free radical mechanism with instantaneous initiation and monomer transfer.

Surface modification of nanoporous alumina membranes by plasma polymerization

Energy Technology Data Exchange (ETDEWEB)

Losic, Dusan; Cole, Martin A; Dollmann, Bjoern; Vasilev, Krasimir; Griesser, Hans J [Ian Wark Research Institute, University of South Australia, Mawson Lakes, Adelaide, SA 5095 (Australia)], E-mail: dusan.losic@unisa.edu.au

2008-06-18

The deposition of plasma polymer coatings onto porous alumina (PA) membranes was investigated with the aim of adjusting the surface chemistry and the pore size of the membranes. PA membranes from commercial sources with a range of pore diameters (20, 100 and 200 nm) were used and modified by plasma polymerization using n-heptylamine (HA) monomer, which resulted in a chemically reactive polymer surface with amino groups. Heptylamine plasma polymer (HAPP) layers with a thickness less than the pore diameter do not span the pores but reduce their diameter. Accordingly, by adjusting the deposition time and thus the thickness of the plasma polymer coating, it is feasible to produce any desired pore diameter. The structural and chemical properties of modified membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray electron spectroscopy (XPS). The resultant PA membranes with specific surface chemistry and controlled pore size are applicable for molecular separation, cell culture, bioreactors, biosensing, drug delivery, and engineering complex composite membranes.

Surface modification of nanoporous alumina membranes by plasma polymerization

International Nuclear Information System (INIS)

Losic, Dusan; Cole, Martin A; Dollmann, Bjoern; Vasilev, Krasimir; Griesser, Hans J

2008-01-01

The deposition of plasma polymer coatings onto porous alumina (PA) membranes was investigated with the aim of adjusting the surface chemistry and the pore size of the membranes. PA membranes from commercial sources with a range of pore diameters (20, 100 and 200 nm) were used and modified by plasma polymerization using n-heptylamine (HA) monomer, which resulted in a chemically reactive polymer surface with amino groups. Heptylamine plasma polymer (HAPP) layers with a thickness less than the pore diameter do not span the pores but reduce their diameter. Accordingly, by adjusting the deposition time and thus the thickness of the plasma polymer coating, it is feasible to produce any desired pore diameter. The structural and chemical properties of modified membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray electron spectroscopy (XPS). The resultant PA membranes with specific surface chemistry and controlled pore size are applicable for molecular separation, cell culture, bioreactors, biosensing, drug delivery, and engineering complex composite membranes

Fabrication of conductive metallized nanostructures from self-assembled amphiphilic triblock copolymer templates: Nanospheres, nanowires, nanorings

International Nuclear Information System (INIS)

Zhu Jintao; Jiang Wei

2007-01-01

Various metallized nanostructures (such as rings, wires with controllable lengths, spheres) have been successfully fabricated by coating metallic nanolayers onto soft nanotemplates through simple electroless methods. In particular, bimetallic nanostructures have been obtained by using simple methods. The multiple functional polymeric nanostructures were obtained through the self-assembly of polystyrene/poly(4-vinyl pyridine) triblock copolymer (P4VP-b-PS-b-P4VP) in selective media by changing the common solvent properties. By combining field emission scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) characterization, it was confirmed that polymer/metal and bimetallic (Au at Ag) core-shell nanostructures could be achieved by chemical metal deposition method

Plasma polymerization at different positions in an asymmetric ethylene discharge

International Nuclear Information System (INIS)

Trieschmann, Jan; Hegemann, Dirk

2011-01-01

The characteristics of plasma polymerization are investigated in an asymmetric, capacitively coupled plasma discharge. Here, the deposition in different plasma zones, i.e. on the driven electrode, within the plasma bulk and the plasma sheath as well as approximately at the plasma-sheath edge, is investigated. Principal expectations are perfectly met, though new interesting dependences of the obtained a-C : H coatings with respect to film properties and deposition rates are also found. That is, the deposition rates as measured on thin, small glass slides placed directly on the electrode are considerably higher than everywhere else in the plasma, yet only single-sided. In contrast, the deposition rates on the samples within the plasma are lowered depending on the exact placement, while a double-sided coating is obtained. Furthermore, film properties, such as the film density, are highly dependent on the sample placement in the plasma, which can even be higher under floating conditions. With simple physical arguments we are able to show the relations between the deposition rate and the energy input into the plasma as well as between the energy density during film growth and the film density itself.

SYNTHESIS AND BIOLOGIC PROPERTIES OF SOME 1-(ALCHYLPHENYL-3-(4-(3-(PYRIDIN-2-ILACRYLOYLPHENYLTHIOUREA

Directory of Open Access Journals (Sweden)

A. Popusoi

2013-06-01

Full Text Available This paper describe the synthesis of some 1-(alchylaril-3-(4-(3-pyridin-2-il acryloylphenylthiourea obtained by condensation of 2-pyridincarboxaldehide with some derivatives of 4-acetylphenilthioureas in basic medium or by addition of aliphatic and aromatic amines to the correspondingisothiocyanatopropenones. 12 new compounds were obtained and their biological properties were analysed. The substituted thioureas by pyridine radicals, morpholine and phenol show a maximum bacteriostatic activity for Gram positive microorganisms like: Staphylococcus Aureus and Enterococcus Faecalis at the minimum inhibitory concentration 9.37-37.5 μM. Antifungal activity for Candida Albicans, Aspergillus Niger, AspergillusFumigatus, Penicillium is weak, in minimum inhibitory concentration 600->600 μM. The leukemia activity like inhibitor (HL-60, is 84-96.9% at the concentration 10-5mol/l and 15- 20% and at the concentrations 10-6, 10-7mol/l.

UV recording with vinyl acetate and muicle dye film

Science.gov (United States)

Toxqui-Lopez, S.; Olivares-Pérez, A.; Santacruz-Vazquez, V.; Fuentes-Tapia, I.; Ordoñez-Padilla, J.

2015-03-01

Nowadays, there are many types of holographic recording medium some of them are photopolymer systems that generally consist of a polymeric host matrix, photopolymerizable momomer, photosensitizing dye and charge transfer agent but some of them have an undesirable feature, the toxicity of their components. Therefore, the present research study material recording, vinyl acetate is selected as polymeric matrix and natural dye from "muicle plant" is used as the photoinitiation these components are not toxic. The films are fabricated using gravity settling method at room temperature by this method, uniform films is obtained with good optical quality. To characterize the medium, been obtained when the coherent reed light (632.8 nm) was sent normally to the grating.

Effects of Polymeric Additives on the Crystallization and Release Behavior of Amorphous Ibuprofen

Directory of Open Access Journals (Sweden)

Su Yang Lee

2013-01-01

Full Text Available Some polymeric additives were studied to understand their effects on the amorphous phase of ibuprofen (IBU, used as a poorly water soluble pharmaceutical model compound. The amorphous IBU in bulk, as well as in nanopores (diameter ~24 nm of anodic aluminum oxide, was examined with the addition of poly(acrylic acid, poly(N-vinyl pyrrolidone, or poly(4-vinylphenol. Results of bulk crystallization showed that they were effective in limiting the crystal growth, while the nucleation of the crystalline phase in contact with water was nearly instantaneous in all cases. Poly(N-vinyl pyrrolidone, the most effective additive, was in specific interaction with IBU, as revealed by IR spectroscopy. The addition of the polymers was combined with the nanoscopic confinement to further stabilize the amorphous phase. Still, the IBU with addition of polymeric additives showed sustained release behavior. The current study suggested that the inhibition of the crystal nucleation was probably the most important factor to stabilize the amorphous phase and fully harness its high solubility.

Morphological, elemental, and optical characterization of plasma polymerized n-butyl methacrylate thin films

Science.gov (United States)

Nasrin, Rahima; Hossain, Khandker S.; Bhuiyan, A. H.

2018-05-01

Plasma polymerized n-butyl methacrylate (PPnBMA) thin films of varying thicknesses were prepared at room temperature by AC plasma polymerization system using a capacitively coupled parallel plate reactor. Field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) analysis, and ultraviolet-visible (UV-Vis) spectroscopic investigation have been performed to study the morphological, elemental, and optical properties of the PPnBMA thin films, respectively. The flat and defect-free nature of thin films were confirmed by FESEM and AFM images. With declining plasma power, average roughness and root mean square roughness increase. Allowed direct transition ( E gd) and indirect transition ( E gi) energy gaps were found to be 3.64-3.80 and 3.38-3.45 eV, respectively, for PPnBMA thin films of different thicknesses. Values of E gd as well as E gi increase with the increase of thickness. The extinction coefficient, Urbach energy, and steepness parameter were also determined for these thin films.

(E-2-(4-Chlorophenoxy-N′-(pyridin-4-ylmethylideneacetohydrazide

Directory of Open Access Journals (Sweden)

Xiao-jin Rao

2013-01-01

Full Text Available In the title compound, C14H12ClN3O2, the acylhydrazone base [C(=O—N—N=C] is essentially planar, with an r.m.s. deviation of 0.0095 Å, and makes a dihedral angle of 12.52 (10°with the pyridine ring. In the crystal, molecules are linked via pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8 graph-set motif. The dimers are linked via C—H...π interactions forming chains along [101].

Rapid anaerobic mineralization of pyridine in a subsurface sediment inoculated with a pyridine-degrading Alcaligenes sp

Energy Technology Data Exchange (ETDEWEB)

Ronen, Z; Bollag, J M [Pennsylvania State Univ., University Park, PA (United States). Lab. of Soil Biochemistry

1992-05-01

A denitrifying bacterium capable of pyridine mineralization under anaerobic conditions was isolated from polluted soil. The bacterium, identified as Alcaligenes sp., was used in inoculation experiments. A subsurface sediment from a polluted site was amended with 10 {mu}g/g {sup 14}C-labeled pyridine, and 250 {mu}g/g nitrate, and then inoculated with the bacterium at an inoculum size of 4.5x10{sup 7} cells/g. After 44 h incubation at 28deg C under anaerobic conditions, 67% of the radioactivity was recovered as {sup 14}CO{sub 2}: 2% was extracted with 50% methanol, and 24% was recovered by combustion of the sediment. Analysis of the methanol extract revealed that no pyridine could be detected in the inoculated sediment. In contrast, mineralization of pyridine by the native microflora in the sediment occurred much more slowly: After 7 days of incubation only 10% of the added radioactivity was recovered as {sup 14}CO{sub 2}. At an inoculum size of 2x10{sup 3} cells/g pyridine mineralization was not as effective as at an inoculum size of 2x10{sup 7} cells/g. It is presumed that suppression of the introduced bacteria by the native microflora of the sediment prevents degradation at a low inoculum size. Amending the sediment with nitrate and phosphate improved pyridine mineralization by the introduced bacterium. These findings demonstrate the feasibility of using soil inoculation anaerobically for the bioremediation of pyridine-polluted soils. (orig.).

Synthesis of polysubstituted 4,5,6,7-tetrahydrofuro[2,3-c]pyridines by a novel multicomponent reaction.

Science.gov (United States)

Fayol, Aude; Zhu, Jieping

2004-01-08

[reaction: see text] A novel three-component synthesis of tetrahydrofuro[2,3-c]pyridines from readily accessible starting materials is described. Simply heating a toluene solution of an aminopentynoate, an aldehyde, and an alpha-isocyanoacetamide in the presence of ammonium chloride provided the 4,5,6,7-tetrahydrofuro[2,3-c]pyridines in good to excellent yield. The fused ring system is produced in this one-pot process by the concomitant formation of five chemical bonds.

Modification of glass fibers to improve reinforcement: a plasma polymerization technique

Czech Academy of Sciences Publication Activity Database

Çökeliler, D.; Erkut, S.; Zemek, Josef; Biederman, H.; Mutlu, M.

2007-01-01

Roč. 23, č. 3 (2007), s. 335-342 ISSN 0109-5641 Institutional research plan: CEZ:AV0Z10100521 Keywords : plasma polymerization * glos-discharge * E-glass fibros * ethylendiamine * 2-hydroxyethyl methacrystalate * triethyleneglycoldimethylether * fibre-reinforced composite ( FRC) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.990, year: 2007

Di-μ-iodido-bis(iodido{methyl 4-[(pyridin-2-ylmethylideneamino]benzoate-κ2N,N′}cadmium

Directory of Open Access Journals (Sweden)

Tushar S. Basu Baul

2013-11-01

Full Text Available The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O22], is generated by the application of a centre of inversion. The Cd—I bond lengths of the central core are close and uniformly longer than the exocyclic Cd—I bond. The coordination sphere of the CdII atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-ylmethylideneamino]benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C—H...O and C—H...π interactions, each involving the pyridine ring.

Synthesis and in-vivo evaluation of C-11 p-PVP-MEMA as a PET radioligand for imaging nicotinic receptors

Energy Technology Data Exchange (ETDEWEB)

Paine, T.; Kassiou, M. [Univ Sydney, Sch Chem, Sydney, NSW 2006 (Australia); Dolle, F.; Langle, S.; Roger, G.; Lagnel-de Bruin, B.; Hinnen, F.; Valette, H.; Bottlaender, M. [CEA, Serv Hosp Frederic Joliot, Inst Imagerie Biomed, F-91401 Orsay (France); Fulton, R.R.; Henderson, D.J. [Royal Prince Alfred Hosp, Dept PET and Nucl Med, Camperdown, NSW 2050 (Australia); Coster, M.J. [Griffith Univ, Eskitis Inst Cell and Mol Therapies, Nathan, Qld 4121 (Australia); Kassiou, M. [Univ Sydney, Discipline Med Radiat Sci, Sydney, NSW2006 (Australia); Brain and Mind Res Inst, Camperdown, NSW2050 (Australia)

2008-07-01

Within the class of (4-pyridinyl)vinyl-pyridines developed by Abbott laboratories as potent neuronal nicotinic acetylcholine receptor ligands, p-PVP-MEMA ({l_brace}oro-5-((E)-2-pyridin-4-yl-vinyl) pyridin-3-yloxy]-1-methylethyl{r_brace} is the lead compound of a novel series that do not display the traditional nicotinic-like pyrrole-ring but still possessing high sub-nanomolar affinity (K-i 0.077 nm-displacement of [H-3](-)cytisine from whole rat brain synaptic membranes). In the present study, p-PVP-MEMA and its nor-derivative ({l_brace}oro-5-((E)-2-pyridin-4- yl-vinyl) pyridin-3-yloxy]-1-methylethyl{r_brace} as precursor for labelling with the short-lived positron-emitter carbon-11 (T{sub 1/2} = 20.4 min) were synthesized in 10 chemical steps from 2-hydroxy-5-nitropyridine and Boc-D-alanine. N-Alkylation of nor-p-PVP-MEMA with [C-11] methyl iodide afforded [C-11]p-PVP-MEMA ({>=} 98% radiochemically pure, specific activity of 86.4 GBq {mu} mol{sup -1}) in 2% (non-decay corrected and non-optimized) radiochemical yield, in 34 min (including HPLC purification and formulation). Preliminary positron emission tomography PET) results obtained in a Papio hamadryas baboon showed that [C-11] p-PVP-MEMA is not a suitable PET-radioligand. (authors)

Modification of the poly(ethylene) terephthalate track membrane structure and surface in the plasma of non-polymerized gases

International Nuclear Information System (INIS)

Kravets, L.I.; Dmitriev, S.N.; Apel, P.Y.

1999-01-01

An investigation of the properties of poly(ethylene) terephthalate track membranes (PETTMs) treated with a plasma RF-discharge in non-polymerized gases has been performed. The influence of the plasma treatment conditions on the basic properties of the membranes has been studied. It was arranged that the effect of non-polymerized gases plasma on the PETTMs results to etching a membrane's surface layer. The membranes' pore size and the form in this case change. It is shown that it is possible to change the structure of track membranes directly by gas discharge etching

Plasma polymerization surface modification of Carbon black and its effect in elastomers

NARCIS (Netherlands)

Mathew, T.; Datta, Rabin; Dierkes, Wilma K.; Talma, Auke; Ooij, W.J.; Noordermeer, Jacobus W.M.

2011-01-01

Surface modification of carbon black by plasma polymerization was aimed to reduce its surface energy in order to compatibilize the filler with various elastomers. A fullerenic carbon black was used for the modification process. Thermogravimetric analysis, wetting behavior with liquids of known

New 1-hydroxy-1,1-bisphosphonates derived from 1H-pyrazolo[3,4-b]pyridine: synthesis and characterization

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Fatima C.; Lucas, Carla; Curto, M. Joao M., E-mail: fatima.teixeira@lneg.pt [Laboratorio Nacional de Energia e Geologia, Lisboa (Portugal); Neves, M. [Instituto Superior Tecnico, Instituto Tecnologico e Nuclear (IST/ITN), Campus Tecnologico e Nuclear, Universidade Tecnica de Lisboa, Sacavem (Portugal); Duarte, M. Teresa; Andre, Vania; Teixeira, Antonio P.S. [Centro de Quimica Estrutural, Instituto Superior Tecnico, Universidade Tecnica de Lisboa (Portugal)

2013-07-15

A number of 1H-pyrazolo[3,4-b]pyridine derivatives, starting from 2-chloro-3-formyl pyridine, was synthesized to obtain new 1-hydroxybisphosphonates, a class of compounds with potential biological interest. Spectroscopic data were used to characterize all compounds and to identify N-1 and N-2 regioisomers, and mono- and bisphosphonates derivatives. X-ray diffractometry studies of compound 7a confirmed the proposed structure. (author)

Synthesis and muscarinic receptor pharmacology of a series of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridine bioisosteres of arecoline

DEFF Research Database (Denmark)

Pedersen, H; Bräuner-Osborne, H; Ball, R G

1999-01-01

A series of O- and ring-alkylated derivatives of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridin-3-ol was synthesized via treatment of appropriately substituted 4-benzylamino-1,2,5,6-tetrahydropyridine-3-carboxamides with hydrogen sulfide and subsequent ring closure by oxidation with bromine. The mus...

The interplay between surface charging and microscale roughness during plasma etching of polymeric substrates

Science.gov (United States)

Memos, George; Lidorikis, Elefterios; Kokkoris, George

2018-02-01

The surface roughness developed during plasma etching of polymeric substrates is critical for a variety of applications related to the wetting behavior and the interaction of surfaces with cells. Toward the understanding and, ultimately, the manipulation of plasma induced surface roughness, the interplay between surface charging and microscale roughness of polymeric substrates is investigated by a modeling framework consisting of a surface charging module, a surface etching model, and a profile evolution module. The evolution of initially rough profiles during plasma etching is calculated by taking into account as well as by neglecting charging. It is revealed, on the one hand, that the surface charging contributes to the suppression of root mean square roughness and, on the other hand, that the decrease of the surface roughness induces a decrease of the charging potential. The effect of charging on roughness is intense when the etching yield depends solely on the ion energy, and it is mitigated when the etching yield additionally depends on the angle of ion incidence. The charging time, i.e., the time required for reaching a steady state charging potential, is found to depend on the thickness of the polymeric substrate, and it is calculated in the order of milliseconds.

The influence of pulse parameters on film composition during pulsed plasma polymerization of diaminocyclohexane

Czech Academy of Sciences Publication Activity Database

Choukourov, A.; Biederman, H.; Slavínská, D.; Trchová, Miroslava; Hollander, A.

174-175, - (2003), s. 863-866 ISSN 0257-8972. [International Conference on Plasma Surface Engineering /8./. Garmisch-Partenkirchen, 09.09.2002-13.09.2002] R&D Projects: GA AV ČR KSK4050111 Keywords : plasma polymerization * chemical derivation * primary and secondary amino groups Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.410, year: 2003

Unconventional hydrogen bonding to organic ions in the gas phase: Stepwise association of hydrogen cyanide with the pyridine and pyrimidine radical cations and protonated pyridine

Energy Technology Data Exchange (ETDEWEB)

Hamid, Ahmed M.; El-Shall, M. Samy, E-mail: mselshal@vcu.edu [Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Hilal, Rifaat; Elroby, Shaaban; Aziz, Saadullah G. [Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2014-08-07

Equilibrium thermochemical measurements using the ion mobility drift cell technique have been utilized to investigate the binding energies and entropy changes for the stepwise association of HCN molecules with the pyridine and pyrimidine radical cations forming the C{sub 5}H{sub 5}N{sup +·}(HCN){sub n} and C{sub 4}H{sub 4}N{sub 2}{sup +·}(HCN){sub n} clusters, respectively, with n = 1–4. For comparison, the binding of 1–4 HCN molecules to the protonated pyridine C{sub 5}H{sub 5}NH{sup +}(HCN){sub n} has also been investigated. The binding energies of HCN to the pyridine and pyrimidine radical cations are nearly equal (11.4 and 12.0 kcal/mol, respectively) but weaker than the HCN binding to the protonated pyridine (14.0 kcal/mol). The pyridine and pyrimidine radical cations form unconventional carbon-based ionic hydrogen bonds with HCN (CH{sup δ+}⋯NCH). Protonated pyridine forms a stronger ionic hydrogen bond with HCN (NH{sup +}⋯NCH) which can be extended to a linear chain with the clustering of additional HCN molecules (NH{sup +}⋯NCH··NCH⋯NCH) leading to a rapid decrease in the bond strength as the length of the chain increases. The lowest energy structures of the pyridine and pyrimidine radical cation clusters containing 3-4 HCN molecules show a strong tendency for the internal solvation of the radical cation by the HCN molecules where bifurcated structures involving multiple hydrogen bonding sites with the ring hydrogen atoms are formed. The unconventional H-bonds (CH{sup δ+}⋯NCH) formed between the pyridine or the pyrimidine radical cations and HCN molecules (11–12 kcal/mol) are stronger than the similar (CH{sup δ+}⋯NCH) bonds formed between the benzene radical cation and HCN molecules (9 kcal/mol) indicating that the CH{sup δ+} centers in the pyridine and pyrimidine radical cations have more effective charges than in the benzene radical cation.

Crystal Structure and Properties of Imidazo-Pyridine Ionic Liquids.

Science.gov (United States)

Farren-Dai, Marco; Cameron, Stanley; Johnson, Michel B; Ghandi, Khashayar

2018-07-05

Computational studies were performed on novel protic ionic liquids imidazolium-[1,2-a]-pyridine trifluoroacetate [ImPr][TFA] synthesized by the reaction of imidazo-[1,2a]-pyridine (ImPr) with trifluoroacetic acid (TFA), and on fused salt imidazolium-[1,2-a]-pyridine maleamic carbonate [ImPr][Mal] synthesized by reaction of ImPr with maleamic acid (Mal). Synthesis was performed as one-pot reactions, which applies green chemistry tenets. Both these compounds begin to decompose at 180°C. Our computational studies suggest another thermal reaction channel, in which [ImPr][Mal] can also thermally polymerizes to polyacrylamide which then cyclizes. This is thermal product remains stable up to 700 degrees, consistent with our thermogravimetric studies. [ImPr][TFA] exhibited good conductivity and ideal ionic behavior, as evaluated by a Walden plot. X-ray crystallography of [ImPr][TFA] revealed a tightly packed system for the crystals as a result of strong ionic interaction, pi-stacking, and fluorine-CH interactions. Both synthesized compounds exhibited some CO 2 absorptivity, with [ImPr][Mal] outperforming [ImPr][TFA] in this regard. The quantum chemistry based computational methods can shed light on many properties of these ionic liquids, but they are challenged in fully describing their ionic nature. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Graft Copolymerization of Styrene from Poly(vinyl alcohol via RAFT Process

Directory of Open Access Journals (Sweden)

Gholam Ali Koohmareh

2011-01-01

Full Text Available Polystyrene, PS, was grafted from poly(vinyl alcohol, PVA, backbone by reversible addition-fragmentation chain transfer (RAFT polymerization. The hydroxyl groups of the PVA were converted into aromatic dithioester RAFT agent and polymerization began in the presence of this agent. The structure of compounds was confirmed by FT-IR and 1HNMR spectroscopy. The graft copolymer was characterized by thermogravimetric analysis (TGA, X-ray diffraction (XRD, and scanning electron microscopy (SEM. Grafted polystyrene chains were cleaved from the PVA backbone by acidic hydrolysis of the PVA-g-PS, and its polydispersity index, PDI, was determined by gel permeation chromatography (GPC showing narrow molecular weight distribution.

Homogeneity characterization of ethylene-co-vinyl acetate copolymer (EVA) and hydrophobic silica nanocomposite by low field NMR

International Nuclear Information System (INIS)

Stael, Giovanni Chaves; Tavares, Maria I.B.

2005-01-01

This project proposes the characterization of a polymeric matrix composite material using nanometric scale hydrophobic silica as charge element, with the ethylene-vinyl acetate (EVA), by using the spin-lattice relaxation time measurement applying the low field NMR

Surface modification of blood-contacting biomaterials by plasma-polymerized superhydrophobic films using hexamethyldisiloxane and tetrafluoromethane as precursors

Energy Technology Data Exchange (ETDEWEB)

Hsiao, Chaio-Ru [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China); Lin, Cheng-Wei [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); Chou, Chia-Man, E-mail: cmchou@vghtc.gov.tw [Department of Surgery, Taichung Veterans General Hospital, No. 1650, Sec. 4, Taiwan Boulevard, Seatwen District, Taichung City 40705, Taiwan (China); Department of Medicine, National Yang-Ming University, No. 155, Sec. 2, Linong Street, Beitou District, Taipei City 11221, Taiwan (China); Chung, Chi-Jen, E-mail: cjchung@seed.net.tw [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, No. 666, Buzih Rd., Beitun District, Taichung City 40601, Taiwan (China); He, Ju-Liang [Department of Materials Science and Engineering, Feng Chia University, No. 100, Wenhwa Rd., Seatwen District, Taichung City 40724, Taiwan (China)

2015-08-15

Highlights: • Biomaterials modified by nanoparticle-containing plasma polymerized films. • A superhydrophoic film was obtained, and the properties of the coating were examined. • In vitro blood compatibility tests revealed neither platelet adhesion nor fibrinogen adsorption. • Surface modification technology of medical devices: non-cytotoxic and no blood clot formation. - Abstract: This paper proposes a plasma polymerization system that can be used to modify the surface of the widely used biomaterial, polyurethane (PU), by employing low-cost hexamethyldisiloxane (HMDSO) and tetrafluoromethane (CF{sub 4}) as precursors; this system features a pulsed-dc power supply. Plasma-polymerized HMDSO/CF{sub 4} (pp-HC) with coexisting micro- and nanoscale morphology was obtained as a superhydrophobic coating material by controlling the HMDSO/CF{sub 4} (f{sub H}) monomer flow ratio. The developed surface modification technology can be applied to medical devices, because it is non-cytotoxic and has favorable hemocompatibility, and no blood clots form when the device surface direct contacts. Experimental results reveal that the obtained pp-HC films contained SiO{sub x} nanoparticles randomly dispersed on the micron-scale three-dimensional network film surface. The −CF functional group, −CF{sub 2} bonding, and SiO{sub x} were detected on the film surface. The maximal water contact angle of the pp-HC coating was 161.2°, apparently attributable to the synergistic effect of the coexisting micro- and nanoscale surface morphology featuring a low surface-energy layer. The superhydrophobic and antifouling characteristics of the coating were retained even after it was rubbed 20 times with a steel wool tester. Results of in vitro cytotoxicity, fibrinogen adsorption, and platelet adhesion tests revealed favorable myoblast cell proliferation and the virtual absence of fibrinogen adsorption and platelet adhesion on the pp-HC coated specimens. These quantitative findings imply

Living atom transfer radical polymerization of 4-acetoxystyrene

DEFF Research Database (Denmark)

Gao, Bo; Chen, Xianyi; Ivan, Bela

1997-01-01

Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine(bpy) as initi......Living atom transfer radical polymerization (ATRP) of 4-acetoxystyrene (1), a protected 4-vinylphenol, leading to poly(4-acetoxystyrene) with well-defined molecular weight and narrow molecular weight distribution was carried out in bulk with a,a'-dibromoxylene(2)/CuBr/2,2-bipyridine......(bpy) as initiating system. A linear (M) over bar(n), versus monomer conversion plot was found in good accordance with the theoretical line, indicating 100% initiating efficiency. The polymerization is first order in respect to monomer up to about 70% monomer conversion. Deviations from linearity at higher conversion...

Tribological behavior of plasma-polymerized aminopropyltriethoxysilane films deposited on thermoplastic elastomers substrates

Energy Technology Data Exchange (ETDEWEB)

Alba-Elías, Fernando, E-mail: fernando.alba@unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/Luis de Ulloa 20, 26004 Logroño, La Rioja (Spain); Sainz-García, Elisa; González-Marcos, Ana [Department of Mechanical Engineering, University of La Rioja, c/Luis de Ulloa 20, 26004 Logroño, La Rioja (Spain); Ordieres-Meré, Joaquín [ETSII, Polytechnic University of Madrid, c/José Gutiérrez Abascal 2, 28006 Madrid (Spain)

2013-07-01

Thermoplastic elastomers (TPE) are multifunctional polymeric materials that are characterized by moderate cost, excellent mechanical properties (high elasticity, good flexibility, hardness, etc.), high tensile strength, oxidation and wettability. With an objective of reducing the superficial friction coefficient of TPE, this work analyzes the characteristics of coating films that are based on aminopropyltriethoxysilane (APTES) over a TPE substrate. Since this material is heat-sensitive, it is necessary to use a technology that permits the deposition of coatings at low temperatures without affecting the substrate integrity. Thus, an atmospheric-pressure plasma jet system (APPJ) with a dielectric barrier discharge (DBD) was used in this study. The coated samples were analyzed by Scanning Electron Microscopy, Atomic Force Microscopy, Fourier-Transform Infrared with Attenuated Total Reflectance Spectroscopy, X-ray Photoelectron Spectroscopy and tribological tests (friction coefficient and wear rate). The studies showed that the coated samples that contain a higher amount of forms of silicon (SiOSi) and nitrogen (amines, amides and imines) have lower friction coefficients. The sample coated at a specific plasma power of 550 W and an APTES flow rate of 1.5 slm had the highest values of SiOSi and nitrogen-containing groups peak intensity and atomic percentages of Si2p and SiO{sub 4}, and the lowest percentages of C1s and average friction coefficient. The results of this research permit one to conclude that APPJ with a DBD is a promising technique to use in coating SiO{sub x} and nitrogen-containing groups layers on polymeric materials. - Highlights: • SiO{sub x} thin films on thermoplastic elastomers by atmospheric pressure plasma jet. • Study of influence of plasma power and precursor flow rate on film's properties. • Friction coefficient is inversely related to the amount of SiOSi and N groups. • Nitrogen groups from the ionization gas (N{sub 2}) seem to

46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and pipe...

Polymerization of phenol by using discharged plasma under hydrothermal state

Energy Technology Data Exchange (ETDEWEB)

Mitsugi, M; Yoshida, A; Watanabe, H; Kiyan, T; Takade, M; Miyaji, K; Kuwahara, Y; Akiyama, H; Hara, M; Sasaki, M [Graduate School of Science and Technology, Kumamoto University (Japan); Namihira, T; Goto, M, E-mail: mgoto@kumamoto-u.ac.j [Bioelectrics Research Center, Kumamoto University 2-39-1 Kurokami, Kumamoto 865-8555 Japan (Japan)

2010-03-01

Supercritical fluid with plasma is a type of green processing media because this technique does not use catalyst and toxic solvents. In this study, we carried out experiments of organic materials in the presence of discharged plasma in sub- and supercritical water to evaluate the possibility for new reactions. For this purpose, we used SUS316 reactor that generates plasma at temperature and pressure up to 573K and 30MPa, respectively. 100 mmol/L aqueous phenol solution was used as starting material. The reactions were carried out at temperature of 523K and under pressure of 25MPa. After a series of reactions, water-soluble, water-insoluble (oily products), solid residue and gaseous product were obtained. For the analysis of these products, HPLC, GC-MS, TOC, GC-TCD and TOF-MS were used. The highest phenol conversion was 16.96% obtained at 523K, 25MPa and with 4000 times discharged plasma. Polymerized phenol was obtained as a product.

Polymerization of phenol by using discharged plasma under hydrothermal state

International Nuclear Information System (INIS)

Mitsugi, M; Yoshida, A; Watanabe, H; Kiyan, T; Takade, M; Miyaji, K; Kuwahara, Y; Akiyama, H; Hara, M; Sasaki, M; Namihira, T; Goto, M

2010-01-01

Supercritical fluid with plasma is a type of green processing media because this technique does not use catalyst and toxic solvents. In this study, we carried out experiments of organic materials in the presence of discharged plasma in sub- and supercritical water to evaluate the possibility for new reactions. For this purpose, we used SUS316 reactor that generates plasma at temperature and pressure up to 573K and 30MPa, respectively. 100 mmol/L aqueous phenol solution was used as starting material. The reactions were carried out at temperature of 523K and under pressure of 25MPa. After a series of reactions, water-soluble, water-insoluble (oily products), solid residue and gaseous product were obtained. For the analysis of these products, HPLC, GC-MS, TOC, GC-TCD and TOF-MS were used. The highest phenol conversion was 16.96% obtained at 523K, 25MPa and with 4000 times discharged plasma. Polymerized phenol was obtained as a product.

Activation and deactivation of neutral palladium(II) phosphinesulfonato polymerization catalysts

KAUST Repository

Rü nzi, Thomas; Tritschler, Ulrich; Roesle, Philipp; Gö ttker-Schnetmann, Inigo J.; Mö ller, Heiko Maa; Caporaso, Lucia; Poater, Albert; Cavallo, Luigi; Mecking, Stefan

2012-01-01

13C-Labeled ethylene polymerization (pre)catalysts [κ2-(anisyl)2P,O]Pd(13CH3)(L) (1-13CH3-L) (L = pyridine, dmso) based on di(2-anisyl)phosphine benzenesulfonate were used to assess the degree of incorporation of 13CH3 groups into the formed

6-Bromo-2-(4-chlorophenyl-3-methyl-3H-imidazo[4,5-b]pyridine

Directory of Open Access Journals (Sweden)

Selma Bourichi

2016-05-01

Full Text Available In the title compound, C13H9BrClN3, the imidazopyridine fused-ring system is almost planar, with r.m.s. deviation of 0.006 (19 Å, and makes a dihedral angle of 29.32 (8° with the mean plane of the 4-chlorophenyl group. In the crystal, C—H...N hydrogen bonds link the molecules into chains propagating in the [100] direction. Weak intermolecular π–π interactions between the five- and six-membered rings of the 3H-imidazo[4,5-b]pyridine moieties of neighbouring molecules [centroid–centroid distance = 3.8648 (12 Å] further consolidate the packing into layers parallel to the ab plane.

Pyrimidine-pyridine ring interconversion

NARCIS (Netherlands)

Plas, van der H.C.

2003-01-01

This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

Science.gov (United States)

Sagar, Belakavadi K; Harsha, Kachigere B; Yathirajan, Hemmige S; Rangappa, Kanchugarakoppal S; Rathore, Ravindranath S; Glidewell, Christopher

2017-03-01

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 F 4 N 3 O 2 S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 21 H 19 ClF 3 N 3 O 2 S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C 22 H 22 F 3 N 3 O 2 S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P2 1 2 1 2 1 , respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R 3 3 (18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Studies on the effect of nano-TiO{sub 2} on vinyl acetate-butyl acrylate latex-based surface coating

Energy Technology Data Exchange (ETDEWEB)

Suma, K.K. [Dept. of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi 22, Kerala (India); Dept. of Chemistry, Maharaja' s College, Ernakulam, Kerala (India); Jacob, Sinto [Dept. of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi 22, Kerala (India); Joseph, Rani, E-mail: rani@cusat.ac.i [Dept. of Polymer Science and Rubber Technology, Cochin University of Science and Technology, Kochi 22, Kerala (India)

2010-04-15

Vinyl acetate-butyl acrylate (VAc-BuA) copolymer latex was prepared by emulsion polymerization. The polymerization conditions and the composition were optimized. The 85/15 wt.% (vinyl acetate/butyl acrylate) gave good tensile strength of the order of 15.6 MPa and a glass transition temperature (T{sub g}) value of -6.49 deg. C. This copolymer was used as a binder in the paint formulation. In this formulation nanosized TiO{sub 2} sol was used as a pigment instead of conventional rutile TiO{sub 2}. Nanosized TiO{sub 2} is prepared by wet process. These nanosized TiO{sub 2} rutile colloidal sol has improved properties such as photostability, UV shielding, dispersion stability, etc. The surface properties of paint were found to be superior compared to commercially used paint.

Resonance Raman detection of iron-ligand vibrations in cyano(pyridine)(octaethylporphinato)iron(III): Effects of pyridine basicity on the Fe-CN bond strength

International Nuclear Information System (INIS)

Uno, Tadayuki; Hatano, Keiichiro; Nishimura, Yoshifumi; Arata, Yoji

1988-01-01

The influence of axial ligand basicity on the bonding of iron(III) in cyano adducts of octaethylporphyrin has been studied by resonance Raman spectroscopy. In a six-coordinate ferric low-spin complex, cyano(pyridine)(octaethylporphinato)iron(III), Fe(OEP)(CN)(py), Raman lines at 449 and 191 cm -1 were assigned to the ν(Fe-CN) and ν(Fe-py) stretching modes, respectively. When pyridine was displaced with its derivatives, py-X, where X = 4-cyano, 3-acetyl, 3-methyl, 4-methyl, 3,4-dimethyl, and 4-dimethylamino, the ν(Fe-CN) stretching frequency was found to decrease in the complex with a high pyridine basicity. It was concluded that the stronger the trans pyridine basicity, the weaker the iron-carbon (cyanide) bond. A clear frequency shift was observed in the ν 4 model, though most of the porphyrin vibrations were insensitive to the ligand substitution. The frequency of the ν 4 mode, which is the C a -N(pyrrole) breathing vibration of the porphyrin skeleton, was found to increase with an increase in pyridine basicity. This is contrary to what was found in ferrous low-spin hemes as CO complexes. The ν 4 shift in the CN complexes was explained in terms of forward π donation; donation of electrons from the porphyrin π orbital to the d π vacancy of the low-spin iron(III) weakened the C a -N(pyrrole) bonds and hence decreased the ν 4 frequency. 32 references, 8 figures

A One-Step Route to CO2 -Based Block Copolymers by Simultaneous ROCOP of CO2 /Epoxides and RAFT Polymerization of Vinyl Monomers.

Science.gov (United States)

Wang, Yong; Zhao, Yajun; Ye, Yunsheng; Peng, Haiyan; Zhou, Xingping; Xie, Xiaolin; Wang, Xianhong; Wang, Fosong

2018-03-26

The one-step synthesis of well-defined CO 2 -based diblock copolymers was achieved by simultaneous ring-opening copolymerization (ROCOP) of CO 2 /epoxides and RAFT polymerization of vinyl monomers using a trithiocarbonate compound bearing a carboxylic group (TTC-COOH) as the bifunctional chain transfer agent (CTA). The double chain-transfer effect allows for independent and precise control over the molecular weight of the two blocks and ensures narrow polydispersities of the resultant block copolymers (1.09-1.14). Notably, an unusual axial group exchange reaction between the aluminum porphyrin catalyst and TTC-COOH impedes the formation of homopolycarbonates. By taking advantage of the RAFT technique, it is able to meet the stringent demand for functionality control to well expand the application scopes of CO 2 -based polycarbonates. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Schiff Bases of Benzothiazol-2-ylamine and Thiazolo[5,4-b] pyridin-2-ylamine as Anticonvulsants: Synthesis, Characterization and Toxicity Profiling.

Science.gov (United States)

Shukla, Rashmi; Singh, Ajeet P; Sonar, Pankaj K; Mishra, Mudita; Saraf, Shailendra K

2016-01-01

Schiff bases have a broad spectrum of biological activities like antiinflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic and so forth. Thus, after a thorough perusal of literature, it was decided to conjugate benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine with aromatic and heteroaromatic aldehydes to get a series of Schiff bases. Synthesis, characterization, in-silico toxicity profiling and anticonvulsant activity of the Schiff bases of Benzothiazol-2-ylamine and Thiazolo [5, 4-b] pyridin-2-ylamine. Aniline/4-aminopyridine was converted to the corresponding thiourea derivatives, which were cyclized to obtain benzothiazol-2-ylamine/thiazolo [5, 4-b] pyridin-2-ylamine. Finally, these were condensed with various aromatic and heteroaromatic aldehydes to obtain Schiff bases of benzothiazol-2-ylamine and thiazolo [5, 4-b] pyridin-2-ylamine. The synthesized compounds were characterized and screened for their anticonvulsant activity using maximal electroshock (MES) test and isoniazid (INH) induced convulsions test. In-silico toxicity profiling of all the synthesized compounds was done through "Lazar" and "Osiris" properties explorer. Majority of the compounds were more potent against MES induced convulsions than INH induced convulsions. Schiff bases of benzothiazol-2-ylamine were more effective than thiazolo [5, 4-b] pyridin-2-ylamine against MES induced convulsions. The compound benzothiazol-2-yl-(1H-indol-2-ylmethylene)-amine (VI) was the most potent member of the series against both types of convulsions. Compound VI exhibited the most significant activity profile in both the models. The compounds did not exhibit any carcinogenicity or acute toxicity in the in-silico studies. Thus, it may be concluded that the Schiff bases of benzothiazol-2-ylamine exhibit the potential to be promising and non-toxic anticonvulsant agents.

Synthesis, Characterization and Conductivity Study of Poly(vinyl 4-HYDROXY-3-METHOXY Benzal) and its Sodio Salt in Solid State

Science.gov (United States)

Borah, P.; Hussain, S.; Dutta, A.

Among the various ion-conducting materials, polymer salt complexes are of current interest due to their possible application as solid electrolyte as well as their physical nature in advanced high-energy electrochemical devices such as batteries, fuel cells, electrochromic display devices, photo electro-chemical solar cells52-55 etc. The main advantages of polymeric electrolytes are their mechanical properties, ease of fabrication of thin films of desired sizes and their ability to form proper electrode-electrolyte contact. Polymer electrolyte usually consists of a polymer and a salt and is considered to be solid solutions in which the polymer functions as solvent. In the present paper the synthesis, characterization and the conductivity study of the polymer poly (vinyl 4-hydroxy-3-methoxy benzal) (PV-HMB) and its sodio salt (PV-HMB-Na) have been reported. The polymer was prepared by carrying out homogenous acetalization between the prepolymer poly vinylalcohol (PVA) and 4-hydroxy-3-methoxy benzaldehyde (vanilline). PVA was dissolved in dimethyl formamide (DMF) and lithium chloride (LiCl) system i.e., in non-aqueous medium. The sodio salt was prepared by alkalization. The polymer and its salt were characterized by IR, 1H NMR and DSC. Frequency and temperature dependence of ac conductivity has been studied to learn about the electrical conduction behaviour in this material. The electrical conductivity of the new polymeric salt was found to be in the range 10-4 to 10-6 Scm-1. There is about 103 to 104 fold increase in the conductivity of the new polymer salt. Apparent activation energy of the polymer and its salt were found to be 0.139 and 0.08998 ev respectively.

Direct Vinylation of Alcohols or Aldehydes Employing Alkynes as Vinyl Donors: A Ruthenium Catalyzed C-C Bond Forming Transfer Hydrogenation

Science.gov (United States)

Patman, Ryan L.; Chaulagain, Mani Raj; Williams, Vanessa M.; Krische, Michael J.

2011-01-01

Under the conditions of ruthenium catalyzed transfer hydrogenation, 2-butyne couples to benzylic and aliphatic alcohols 1a–1i to furnish allylic alcohols 2a–2i, constituting a direct C-H vinylation of alcohols employing alkynes as vinyl donors. Under related transfer hydrogenation conditions employing formic acid as terminal reductant, 2-butyne couples to aldehydes 4a, 4b, and 4e to furnish identical products of carbonyl vinylation 2a, 2b, and 2e. Thus, carbonyl vinylation is achieved from the alcohol or the aldehyde oxidation level in the absence of any stoichiometric metallic reagents. Nonsymmetric alkynes 6a–6c couple efficiently to aldehyde 4b to provide allylic alcohols 2m–2o as single regioisomers. Acetylenic aldehyde 7a engages in efficient intramolecular coupling to deliver cyclic allylic alcohol 8a. PMID:19173651

Pyridinium bis­(pyridine-κN)tetra­kis­(thio­cyanato-κN)ferrate(III)–pyrazine-2-carbo­nitrile–pyridine (1/4/1)

Science.gov (United States)

Shylin, Sergii I.; Gural’skiy, Il’ya A.; Haukka, Matti; Golenya, Irina A.

2013-01-01

In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2]·4C5H3N3·C5H5N, the FeIII ion is located on an inversion centre and is six-coordinated by four N atoms of the thio­cyanate ligands and two pyridine N atoms in a trans arrangement, forming a slightly distorted octa­hedral geometry. A half-occupied H atom attached to a pyridinium cation forms an N—H⋯N hydrogen bond with a centrosymmetrically-related pyridine unit. Four pyrazine-2-carbo­nitrile mol­ecules crystallize per complex anion. In the crystal, π–π stacking inter­actions are present [centroid–centroid distances = 3.6220 (9), 3.6930 (9), 3.5532 (9), 3.5803 (9) and 3.5458 (8) Å]. PMID:23723782

Proof of concept for molecular velcro based on the attractive interaction between porphyrin and pyridine containing copolymers

Directory of Open Access Journals (Sweden)

M. Sievers

2018-06-01

Full Text Available In this short communication, we investigated the synthesis and mixing of porphyrin and pyridine functionalized copolymers as a proof of concept for a velcro-like interaction. A functionalized porphyrin monomer with one polymerizable side chain was synthesized following a rational synthetic pathway. Subsequent copolymerization and careful removal of residual free porphyrin led to poly(n-butyl acrylate-co-5,10,15-triphenyl-20-(3-vinylphenylporphyrin. The immobilized porphyrin was transformed into the corresponding zinc(II complex, which is capable of the coordinative binding of one pyridine moiety. Complete metallation was proven by absorption spectroscopy. 4-Vinylpyridine was immobilized by copolymerization with n-butyl acrylate, too. Via controlled radical polymerization conditions, the molecular weight of poly(n-butyl acrylate-co-4-vinylpyridine was limited to one tenth of the molecular weight of the porphyrin containing copolymer. This large difference in the molecular weight easily allowed identifying the polymers in the mixture of both. With the help of diffusion ordered nuclear magnetic resonance spectroscopy, the complete and temperature-stable precipitation of the porphyrin containing copolymer was observed, proving the expected attractive interaction and supramolecular network formation.

Plasma polymerization coating of D-T filled glass shells for laser fusion targets

International Nuclear Information System (INIS)

Johnson, W.L.; Hatcher, C.W.; Hendricks, C.D.; Letts, S.A.; Lorensen, L.E.

1977-01-01

Three plasma sources are described which activate monomers of perfluoro-2-butene or tetrafluoroethylene to produce coatings 10 to 20 μm thick with surfaces finishes <0.1 μm. Electrical and chemical controls of the polymerization processes are shown to improve the surface finish

Degradation of pyridine and quinoline in aqueous solution by gamma radiation

Science.gov (United States)

Chu, Libing; Yu, Shaoqing; Wang, Jianlong

2018-03-01

In present work, the degradation of two N-heteroaromatic pollutants, i.e., pyridine and quinoline was investigated by gamma irradiation in the presence of TiO2 nanoparticle. The experimental results showed that quinoline has a higher degradation rate than pyridine. The removal efficiency of the pollutants, TOC and TN reached 93.0%, 11.9% and 12.0% for quinoline, 71.0%, 10.6% and 4.4% for pyridine, respectively at 7.0 kGy and initial concentration of 50 mg/L. Ammonium was detected for both pyridine and quinoline within the absorbed doses, suggesting that the organic nitrogen was transformed into ammonium. The degradation rate constant of pyridine and quinoline was increased by 1.1-1.5 times with addition of TiO2. TiO2 nanoparticles were especially effective to enhance the mineralization. The removal efficiency of TOC and TN was increased by 15-12% for pyridine and 23-25% for quinoline, respectively in the presence of 2.0 g/L TiO2. Following gamma irradiation, 2-hydroxypyridine, 3-hydroxypyridine, oxalic acid and formic acid were identified for pyridine and the hydroxyl quinoline and formic acid were detected for quinoline. Accordingly, the degradation mechanism of pyridine and quinoline by gamma irradiation was tentatively proposed.

Poly[propane-1,3-diammonium [cuprate(II-bis(μ2-pyridine-2,3-dicarboxylato] trihydrate

Directory of Open Access Journals (Sweden)

Shabnam Hooshmand

2008-02-01

Full Text Available The title polymeric compound {(C3H12N2[Cu(C7H3NO42]·3H2O}n or {(pnH2[Cu(py-2,3-dc2]·3H2O}n (pn is propane-1,3-diamine and py-2,3-dcH2 is pyridine-2,3-dicarboxylic acid, was synthesized by reaction of copper(II chloride dihydrate with a proton-transfer compound, propane-1,3-diammonium pyridine-2,3-dicarboxylate or (pnH2(py-2,3-dc, in aqueous solution. The anion is a six-coordinate complex (site symmetry overline{1}, with a distorted octahedral geometry around CuII, consisting of two bidentate pyridine-2,3-dicarboxylate groups and two O atoms of bridging ligands from (py-2,3-dc2− fragments, which are located in trans positions. The (pnH22+ cation is disordered over two sites by the center of inversion. Intermolecular hydrogen bonds, π–π [centroid–centroid distances of 3.539 (3 Å] and C—O...π stacking interactions [O...Cg = 3.240 (5 Å; Cg is the center of the pyridine ring], connect the various components into a supramolecular structure.

SO ₂ Phototriggered Crystalline Nanomechanical Transduction of Aromatic Rotors in Tosylates: Rationalization via Photocrystallography of [Ru(NH ₃ ) ₄ SO ₂ X]tosylate ₂ (X = pyridine, 3-Cl-pyridine, 4-Cl-pyridine)

Energy Technology Data Exchange (ETDEWEB)

Sylvester, Sven O.; Cole, Jacqueline M.; Waddell, Paul G.; Nowell, Harriott; Wilson, Claire

2014-07-24

Thermally-reversible solid-state linkage SO2 photoisomers of three complexes in the [Ru(NH3)4SO2X]tosylate2 family are captured in their metastable states using photocrystallography, where X = pyridine (1), 3-Cl-pyridine (2) and 4-Cl-pyridine (3). This photoisomerism only exists in the single-crystal form; accordingly, the nature of the crystalline environment surrounding the photo-active species controls its properties. In particular, the structural role of the tosylate anion needs to be understood against possible chemical influences due to varying the trans ligand, X. The photo-excited geometries, photoconversion levels and thermal stabilities of the photoisomers that form in 1-3 are therefore studied. 1 and 2 yield two photo-isomers at 100 K: the O-bound end-on n1-SO2 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry (MS1) configuration and the side-bound n2-SO2 (MS2), while 3 only exhibits the more thermally stable MS2 geometry. The decay kinetics of the MS2 geometry for 1-3 demonstrate that the greater the free volume of the GS SO2 ligand for a given counterion, the greater the MS2 thermal stability. Furthermore, a rationalization is sought for the SO2 phototriggered molecular rotation of the phenyl ring in the tosylate anion; this is selectively observed in 2, manifesting as nanomechanical molecular transduction. This molecular transduction was not observed in 1, despite the presence of the MS1 geometry due to the close intermolecular interactions between the MS1 SO2 and the neighbouring tosylate ion. The decay of this anionic molecular rotor in 2, however, follows a non-traditional decay pathway, as determined by time-resolved crystallographic analysis; this contrasts with the well-behaved first-order kinetic decay of its MS1 SO2 phototrigger.

Elimination of defects in plasma polymerized films used in laser fusion targets

International Nuclear Information System (INIS)

Letts, S.A.; Johnson, W.L.; Myers, D.W.; Illige, J.D.; Lorensen, L.E.; Hatcher, C.W.

1979-01-01

This study was conducted to understand and control the parameters governing the formation of defects in plasma polymerized surfaces. An inductively-coupled discharge was used as the source of activated monomer. Four types of well characterized surface irregularities were produced on glass slides which were subsequently fluorocarbon coated. Optimization of the process variables is discussed

Synthesis and Characterization of Waterborne Fluoropolymers Prepared by the One-Step Semi-Continuous Emulsion Polymerization of Chlorotrifluoroethylene, Vinyl Acetate, Butyl Acrylate, Veova 10 and Acrylic Acid

Directory of Open Access Journals (Sweden)

Hongzhu Liu

2017-01-01

Full Text Available Waterborne fluoropolymer emulsions were synthesized using the one-step semi-continuous seed emulsion polymerization of chlorotrifluoroethylene (CTFE, vinyl acetate (VAc, n-butyl acrylate (BA, Veova 10, and acrylic acid (AA. The main physical parameters of the polymer emulsions were tested and analyzed. Characteristics of the polymer films such as thermal stability, glass transition temperature, film-forming properties, and IR spectrum were studied. Meanwhile, the weatherability of fluoride coatings formulated by the waterborne fluoropolymer and other coatings were evaluated by the quick ultraviolet (QUV accelerated weathering test, and the results showed that the fluoropolymer with more than 12% fluoride content possessed outstanding weather resistance. Moreover, scale-up and industrial-scale experiments of waterborne fluoropolymer emulsions were also performed and investigated.

Synthesis and antimicrobial activity of guanylhydrazones. Synthesis of 2-(2-methylthio-2-aminovinyl)-1-methylpyridinium iodides and 2-(2-methylthio-2-aminovinyl)-1-methylquinolinium iodides as potential radioprotective and anticancer agents

International Nuclear Information System (INIS)

Almassian, B.

1985-01-01

The finding of appreciable antileukemic activity in a series of 2-(2-methylthio-2-amino)vinyl-1-methylquinolinium iodides (Foye et al., 1980, 1983) suggested that greater basicity, as compared with the corresponding dithioacetic acids, was contributing to the increase in activity. The addition of a greater degree of basicity in the design of anticancer possibilities in this series was considered worth investigation, particularly in view of the activity of a series of bis(quanylhydrazones) synthesized at Lederle Laboratories. Accordingly, a series of guanylhydrazones of 4-pyridine-,2-pyridine- and 4-quinolinecarboxyaldehydes was synthesized for anticancer as well as antibacterial screening. Also, substitution of additional basic functions in the 2-(2-methylthio-2-amino) vinyl-1-methylquinolinium and pyridinium iodide series has been made. Appreciable antimicrobial activities have been found with both 2-pyridine and 4-quinolinealdehyde guanylhydrazones, as well as with 2-(2-methylthio-2-amino)vinyl-1-methyl-pyridinium iodides. The overall approach to the synthesis of potential anticancer agents in this project is thus to observe the effect of increasing basicity of these compounds on DNA binding and anticancer activity

Conjugate Addition of Nucleophiles to the Vinyl Function of 2-Chloro-4-vinylpyrimidine Derivatives

Directory of Open Access Journals (Sweden)

Lucjan Strekowski

2010-03-01

Full Text Available Conjugate addition reaction of various nucleophiles across the vinyl group of 2-chloro-4-vinylpyrimidine, 2-chloro-4-(1-phenylvinylpyrimidine and 2-chloro-4-vinylquinazoline provides the corresponding 2-chloro-4-(2-substituted ethylpyrimidines and 2-chloro-4-(2-substituted ethylquinazolines. Treatment of these products, without isolation, with N-methylpiperazine results in nucleophilic displacement of chloride and yields the corresponding 2,4-disubstituted pyrimidines and quinazolines.

Enhanced corrosion resistance and hemocompatibility of biomedical NiTi alloy by atmospheric-pressure plasma polymerized fluorine-rich coating

Energy Technology Data Exchange (ETDEWEB)

Li, Penghui; Li, Limin [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Wang, Wenhao [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Division of Spine Surgery, Department of Orthopaedics and Traumatology, Pokfulam, Hong Kong (China); Jin, Weihong [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Liu, Xiangmei [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan, Hubei 430062 (China); Yeung, Kelvin W.K. [Division of Spine Surgery, Department of Orthopaedics and Traumatology, Pokfulam, Hong Kong (China); Chu, Paul K., E-mail: paul.chu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)

2014-04-01

Highlights: • Fluoropolymer is deposited on NiTi alloy via atmospheric-pressure plasma polymerization. • The corrosion resistance of NiTi alloy in SBF and DMEM is evidently improved. • The adsorption ratio of albumin to fibrinogen is increased on the coated surface. • The reduced platelet adhesion number indicates better in vitro hemocompatibility. - Abstract: To improve the corrosion resistance and hemocompatibility of biomedical NiTi alloy, hydrophobic polymer coatings are deposited by plasma polymerization in the presence of a fluorine-containing precursor using an atmospheric-pressure plasma jet. This process takes place at a low temperature in air and can be used to deposit fluoropolymer films using organic compounds that cannot be achieved by conventional polymerization techniques. The composition and chemical states of the polymer coatings are characterized by fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the coated and bare NiTi samples is assessed and compared by polarization tests and electrochemical impedance spectroscopy (EIS) in physiological solutions including simulated body fluids (SBF) and Dulbecco's Modified Eagle's medium (DMEM). The corrosion resistance of the coated NiTi alloy is evidently improved. Protein adsorption and platelet adhesion tests reveal that the adsorption ratio of albumin to fibrinogen is increased and the number of adherent platelets on the coating is greatly reduced. The plasma polymerized coating renders NiTi better in vitro hemocompatibility and is promising as a protective and hemocompatible coating on cardiovascular implants.

Triblock and pentablock terpolymers by sequential base-assisted living cationic copolymerization of functionalized vinyl ethers

KAUST Repository

Bouchekif, Hassen; Sulhami, A. I.; AlGhamdi, Rayed D.; Gnanou, Yves; Hadjichristidis, Nikolaos

2015-01-01

A series of novel, well-defined triblock (PnBVE-b-PCEVE-b-PSiDEGVE) and pentablock (PSiDEGVE-b-PCEVE-b-PnBVE-b-PCEVE-b-PSiDEGVE) terpolymers of n-butyl vinyl ether (nBVE), 2-chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl ether (SiEGVE) were synthesized by sequential base-assisted living cationic polymerization. The living character of the homopolymerization of the three VE monomers and the crossover reaction resulting in the formation of well-defined block copolymers were investigated in various solvents (toluene, dichloromethane and n-hexane) using either a monofunctional [nBVE-acetic acid adduct (nBEA), CEVE-acetic acid adduct (CEEA) and SiDEGVE-acetic acid adduct (SiDEGEA)] or a difunctional [1,4-cyclohexane-1,4-diyl bis(2-methoxyethyl acetate) (cHDMEA)] initiator. All initiators are structurally equivalent to the dormant species of the corresponding monomers in order to achieve fast initiation. The optimal conditions of polymerization were achieved in n-hexane at -20 °C, in the presence of 1 M AcOEt (base). Good control over the number average molecular weight (Mn) and the polydispersity index (PDI) was obtained only at [Et3Al2Cl3]0 = [Chain-end]0 ≤ 10 mM. 2,6-Di-tert-butylpyridine (DtBP) was used as a non-nucleophilic proton trap to suppress any protonic initiation from moisture (i.e., Et3Al2Cl3·H2O). Well-defined PnBVEn-b-PCEVEp-b-PSiDEGVEq and PSiDEGVEq-b-PCEVEp-b-PnBVEn-b-PCEVEp-b-PSiDEGVEq terpolymers with a high crossover efficiency, no PCEVE-induced physical gelation, and predictable Mn and PDI < 1.15 were synthesized successfully provided that the targeted DPCEVE/DPnBVE ratio (i.e., p/n) did not exceed 2 and 0.2, respectively. The quantitative desilylation of the PSiEGVE by n-Bu4N+F- in THF at 0 °C led to triblock and pentablock terpolymers in which the PCEVE is the central block and the polyalcohol is the outer block. The thermal properties of the synthesized materials were examined by differential scanning

A fluorescent molecular sensor for pH windows in traditional and polymeric biocompatible micelles: comicellization of anionic species to shift and reshape the ON window.

Science.gov (United States)

Cavallaro, Gennara; Giammona, Gaetano; Pasotti, Luca; Pallavicini, Piersandro

2011-09-12

A new approach is presented to obtain fluorescent sensors for pH windows that work in water and under biomimetic conditions. A single molecule that features all-covalently linked components is used, thus making it capable of working as a fluorescent sensor with an OFF/ON/OFF response to pH value. The components are a tertiary amine, a pyridine, and a fluorophore (pyrene). The forms with both protonated bases or both neutral bases quench the pyrene fluorescence, whereas the form with the neutral pyridine and protonated amine groups is fluorescent. The molecular sensor is also equipped with a long alkyl chain to make it highly hydrophobic in all its protonated and unprotonated forms, that is, either when neutral or charged. Accordingly, it can be confined at any pH value either in traditional (i.e., low-molecular-weight) nonionic surfactant micelles or inside polymeric, biocompatible micellar containers. Relevant for future applications in vivo, thanks to its strong hydrophobicity, no leakage of the molecular sensor is observed from the polymeric biocompatible micelles. Due to the proximity of the pyridine and amine functions in the molecular structure and the poor hydration inside the micelles, the observed pK(a) values are low so that the ON window is positioned at very low pH values. However, the window can be shifted to biologically relevant values by comicellization of anionic species. In particular, in the micelles of the nonionic surfactant TritonX-100, a shift of the ON window to pH 4-6 is obtained by addition of the anionic sodium dodecyl sulphate surfactant, whose negative charge promotes the stability of the protonated forms of the pyridine and amine fragments. In the case of the polymeric micelles, we introduce the use of the amphiphilic polystyrene sulfonate anionic polyelectrolyte, the comicellization of which induces a shift and sharpening of the ON window that is centered at pH 4. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling

International Nuclear Information System (INIS)

Vasquez, M.; Cruz, G.; Olayo, M.G.; Timoshina, T.; Morales, J.; Olayo, R.

2004-01-01

It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

Metal-catalyzed living radical polymerization and radical polyaddition for precision polymer synthesis

Energy Technology Data Exchange (ETDEWEB)

Mizutani, M; Satoh, K [Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Kamigaito, M, E-mail: kamigait@apchem.nagoya-u.ac.j

2009-08-01

The metal-catalyzed radical addition reaction can be evolved into two different polymerization mechanisms, i.e.; chain- and step-growth polymerizations, while both the polymerizations are based on the same metal-catalyzed radical formation reaction. The former is a widely employed metal-catalyzed living radical polymerization or atom transfer radical polymerization of common vinyl monomers, and the latter is a novel metal-catalyzed radical polyaddition of designed monomer with an unconjugated C=C double bond and a reactive C-Cl bond in one molecule. The simultaneous ruthenium-catalyzed living radical polymerization of methyl acrylate and radical polyaddition of 3-butenyl 2-chloropropionate was achieved with Ru(Cp*)Cl(PPh{sub 3}){sub 2} to afford the controlled polymers, in which the homopolymer segments with the controlled chain length were connected by the ester linkage.

Synthesis of 2,4,6-Trisubstituted Pyridines by Oxidative Eosin Y Photoredox Catalysis.

Science.gov (United States)

Rohokale, Rajendra S; Koenig, Burkhard; Dhavale, Dilip D

2016-08-19

Eosin Y, an organic dye, was activated as a photoredox catalyst in the presence of molecular oxygen using visible light and, when it was used in the reaction of aryl ketones and benzyl amines, afforded good yields (52-87%) of 2,4,6-triarylpyridines (21 examples) at ambient temperature. The aryl groups at the 2- and 6-positions are derived from ketones, while benzyl amine plays the dual role of providing an aryl functionality at the 4-position of pyridine as well as being a nitrogen donor.

Crystal structure of [2-({4-[2,6-bis(pyridin-2-ylpyridin-4-yl]phenyl}(methylaminoethanol-κ3N,N′,N′′]bis(thiocyanato-κNzinc N,N-dimethylformamide monosolvate

Directory of Open Access Journals (Sweden)

Shi-Chao Wang

2014-10-01

Full Text Available In the title compound, [Zn(NCS2(C24H22N4O]·C3H7NO, the ZnII cation is N,N′,N′′-chelated by one 2-({4-[2,6-bis(pyridin-2-ylpyridin-4-yl]phenyl}(methylaminoethanol ligand and coordinated by two thiocyanate anions in a distorted N5 trigonal–bipyramidal geometry. In the molecule, the three pyridine rings are approximately coplanar [maximum deviation = 0.026 (5 Å], and the mean plane of the three pyridine rings is twisted to the benzene ring with a small dihedral angle of 5.9 (2°. In the crystal, complex molecules are linked by weak C—H...O hydrogen bonds into supramolecular chains propagated along [110]; π–π stacking is observed between adjacent chains [centroid–centroid distance = 3.678 (4 Å]. The dimethylformamide solvent molecules are linked with the complex chains via weak C—H...O hydrogen bonds.

Surface modification of silicon wafer by grafting zwitterionic polymers to improve its antifouling property

Science.gov (United States)

Sun, Yunlong; Chen, Changlin; Xu, Heng; Lei, Kun; Xu, Guanzhe; Zhao, Li; Lang, Meidong

2017-10-01

Silicon (111) wafer was modified by triethoxyvinylsilane containing double bond as an intermedium, and then P4VP (polymer 4-vinyl pyridine) brush was "grafted" onto the surface of silicon wafer containing reactive double bonds by adopting the "grafting from" way and Si-P4VP substrate (silicon wafer grafted by P4VP) was obtained. Finally, P4VP brush of Si-P4VP substrate was modified by 1,3-propanesulfonate fully to obtain P4VP-psl brush (zwitterionic polypyridinium salt) and the functional Si-P4VP-psl substrate (silicon wafer grafted by zwitterionic polypyridinium salt based on polymer 4-vinyl pyridine) was obtained successfully. The antifouling property of the silicon wafer, the Si-P4VP substrate and the Si-P4VP-psl substrate was investigated by using bovine serum albumin, mononuclear macrophages (RAW 264.7) and Escherichia coli (E. coli) ATTC25922 as model bacterium. The results showed that compared with the blank sample-silicon wafer, the Si-P4VP-psl substrate had excellent anti-adhesion ability against bovine serum albumin, cells and bacterium, due to zwitterionic P4VP-psl brush (polymer 4-vinyl pyridine salt) having special functionality like antifouling ability on biomaterial field.

Protonation of pyridine. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

Zahran, N F; Ghoniem, H; Helal, A I [Physics Dept., Nuclear Research Center, AEA., Cairo, (Egypt); Rasheed, N [Nuclear Material Authority, Cairo, (Egypt)

1996-03-01

Field ionization mass spectra of pyridine is measured using 10{mu}m activated wire. protonation of pyridine, is observed as an intense peak in the mass spectra. Charge distribution of pyridine molecule is calculated using the modified neglect of diatomic overlap (MNDO) technique, and consequently proton attachment is proposed to be on the nitrogen atom. Temperature dependence of (M+H){sup +} ion is investigated and discussed. MNDO calculations of the protonated species are done, and the proton affinity of pyridine molecule is estimated. Time dependence of the field ionization process of pyridine and protonated ions are observed and discussed. 5 figs.

The btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] binding motif: a new versatile terdentate ligand for supramolecular and coordination chemistry.

Science.gov (United States)

Byrne, Joseph P; Kitchen, Jonathan A; Gunnlaugsson, Thorfinnur

2014-08-07

Ligands containing the btp [2,6-bis(1,2,3-triazol-4-yl)pyridine] motif have appeared with increasing regularity over the last decade. This class of ligands, formed in a one pot ‘click’ reaction, has been studied for various purposes, such as for generating d and f metal coordination complexes and supramolecular self-assemblies, and in the formation of dendritic and polymeric networks, etc. This review article introduces btp as a novel and highly versatile terdentate building block with huge potential in inorganic supramolecular chemistry. We will focus on the coordination chemistry of btp ligands with a wide range of metals, and how it compares with other classical pyridyl and polypyridyl based ligands, and then present a selection of applications including use in catalysis, enzyme inhibition, photochemistry, molecular logic and materials, e.g. polymers, dendrimers and gels. The photovoltaic potential of triazolium derivatives of btp and its interactions with anions will also be discussed.

Vinyl Acetate/butyl acrylate/acrylate Research of Ternary Soap-free Emulsion Polymerization

Directory of Open Access Journals (Sweden)

Xiao Li-guang

2016-01-01

Full Text Available Through the vinyl acetate/butyl acrylate/acrylic acrylic emulsion preparation without soap vinegar, with solid content, gel, emulsion stability and film forming properties and tensile strength as the main index to study the effect of raw materials on the properties of emulsion. Through the infrared spectrometer soap-free emulsion for microscopic analysis research. Study of the ternary soap-free vinegar acrylic emulsion with good performance.

Improvement of wood quality used in Syria by irradiation polymerization

International Nuclear Information System (INIS)

Bakarji, E. H.

2002-06-01

Wood plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, and with Okoume (aucoumea klaineana pierre) imported to Syria in large quantities. Three monomer systems; acrylamide, butylmethacrylate, and styrene were used. polymerization was induced at various radiation doses (10, 20, and 30 kGy) to study the role of radiation doses using a 60 Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength or tensile strength of the obtained wood polymer composites (WPC) were studied. The effect of the additives, sulfuric acid (H + ), N-vinyl pyrrolidone (NVP), trimethyolpropane triacrylate (TMPTA), urea (U), lithium nitrate (LiNo 3 ), copper sulfate (CuSO 4 ) and co-additives on monomer system polymerization were also investigated. Methanol, water and water/methanol mixtures were used as the swelling agents. In general, the use of additives and co-additives brought about an enhancement of tensile strength or compression strength and polymer loading of the composites. In some cases, additives also lowered the monomer concentration and the gamma radiation dose required for polymerization (author)

Synthesis of Lipophilic Antioxidants by a Lipase-B-Catalyzed Addition of Peracids to the Double Bond of 4-Vinyl-2-methoxyphenol.

Science.gov (United States)

Zago, Erika; Durand, Erwann; Barouh, Nathalie; Lecomte, Jérôme; Villeneuve, Pierre; Aouf, Chahinez

2015-10-21

4-Vinyl guaiacol (2) was lipophilized through the electrophilic addition of peracids to its vinylic double bond. Those peracids were formed in situ, by the Candida antarctica lipase-B-assisted perhydrolysis of carboxylic acids ranging from C2 to C18, in hydrogen peroxide solution. The addition of peracids with 4-8 carbons in their alkyl chains led to the formation of two regioisomers, with the prevalence of hydroxyesters bearing a primary free hydroxyl (4c-4e). This prevalence became more pronounced when peracids with longer alkyl chains (C10-C18) were used. In this case, only isomers 4f-4h were formed. The antioxidant activity of the resulting hydroxyesters was assessed by means of the conjugated autoxidizable triene (CAT) assay, and it was found out that the 4-vinyl guaiacol antioxidant activity was significantly increased by grafting alkyl chains with 2-8 carbons.

Novel synthesis on poly (vinyl alcohol): characterization, complexation a biological activity

International Nuclear Information System (INIS)

El-Sawy, N.M.; Elassar, A.Z.; Al-Fulaij, O.

2002-01-01

Poly(vinyl alcohol), PVA, readily condensed with phenyl hydrazine and malononitrile in basic medium to give the hydrazone and pyran derivatives, respectively. PVA reacted with chloroacetonitrile, biuet and thiophene carbonyl chloride to give modified polymeric materials. While addition of PVA to acrylonitrile and phenyl isothiocyanate gives the ether and thiocarbamate ester derivatives, respectively. Hydroxylamine hydrochloride reacted with the modified, carbonitrile containing, polymer to give the amidoxime derivative. The amidoximated products of PVA and carbamate ester of polymeric material were complexed with CUCL2 solution. The complex materials were confirmed by using UV and ESDS measurements. The morphology of PVA and complex with CUII was observed by SEM. Biological activity of some of the prepared compounds was investigated toward bacteria and fungi

5-Bromo-N3-[(E-(6-bromopyridin-2-ylmethylidene]pyridine-3,4-diamine

Directory of Open Access Journals (Sweden)

Mingjian Cai

2011-12-01

Full Text Available The title compound, C11H8Br2N4, is a Schiff base obtained from 6-bromopicolinaldehyde and 5-bromopyridine-3,4-diamine. The molecule has an E configuration about the C=N bond and the dihedral angle between the two pyridine rings is 14.02 (1°. The observed conformation is stabilised by an intramolecular N—H...N hydrogen bond. In the crystal, molecules are stacked along the b axis and are linked through N—H...N hydrogen bonds into chains along the c axis.

Permeation of supercritical carbon dioxide through polymeric hollow fiber membranes

NARCIS (Netherlands)

Patil, V.E.; Broeke, van den L.J.P.; Vercauteren, F.F.; Keurentjes, J.T.F.

2006-01-01

Permeation of carbon dioxide was measured for two types of composite polymeric hollow fiber membranes for feed pressures up to 18 MPa at a temp. of 313 K. support membrane. The membranes consist of a polyamide copolymer (IPC) layer or a poly(vinyl alc.) (PVA) layer on top of a polyethersulfone

Gas-Phase Infrared Spectra of Vinyl Selenol and Vinyl Tellurol

Science.gov (United States)

Benidar, Abdessamad; Khater, Brahim; Guillemin, Jean-Claude; Gámez, José A.; Yáñez, Manuel

2009-10-01

The infrared spectra (3500-500 cm-1) of gaseous vinyl selenol and vinyl tellurol have been recorded at 0.1 cm-1 resolution. For the latter the spectra were obtained at room temperature, but for the former a temperature of -40 °C was required because of the chemical instability of vinyl selenol at room temperature. To compensate the very weak vapor pressure of vinyl tellurol at room temperature, a long optical path up to 136 m was necessary to record its spectrum. B3LYP density functional theory (DFT) calculations have been performed to assign the different absorption bands. Since an unambiguous assignment of the absorption bands requires a precise knowledge on the relative abundance of the syn and gauche rotamers of these compounds, their relative energies and their anharmonic vibrational frequencies were obtained using a very extended Def2-QZVP basis set. Two rotamers, the syn, which is planar, and a nonplanar gauche, were found to be local minima for both compounds. The gauche rotamer presents two degenerate conformers, which differ by the position of the SeH (TeH) hydrogen atom above or below the molecular plane. Our theoretical results are in good agreement with the main features of the experimental spectra. Fundamental bands and some combination bands of vinyl selenol and vinyl tellurol were assigned and compared with those of vinyl alcohol and vinyl thiol, whose spectra had been reported previously in the literature.

Ultrasmooth plasma polymerized coatings for laser-fusion targets

International Nuclear Information System (INIS)

Letts, S.A.; Myers, D.W.; Witt, L.A.

1980-01-01

Coatings for laser fusion targets were deposited up to 135 μm thick by plasma polymerization onto 140 μm diameter DT filled glass microspheres. Ultrasmooth surfaces (no defect higher than 0.1 μm) were achieved by eliminating particulate contamination. Process generated particles were eliminated by determining the optimum operating conditions of power, gas flow, and pressure, and maintaining these conditions through feedback control. From a study of coating defects grown over known surface irregularities, a quantitative relationship between irregularity size, film thickness, and defect size was determined. This relationship was used to set standards for the maximum microshell surface irregularity tolerable in the production of hydrocarbon or fluorocarbon coated laser fusion targets

Syntheses and structures of three heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid

International Nuclear Information System (INIS)

Fang, Wei-Hui; Yang, Guo-Yu

2014-01-01

Three lanthanide–transition-metal coordination polymers, namely, [Er 2 L 6 (H 2 O)][Cu 2 I 2 ] (1), [ErL 3 ][CuI] (2), and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ] (3) (HL=4-pyridin-3-yl-benzoic acid, H 2 BPDC=4,4′-biphenyldicarboxylic acid) have been made by reacting Ln 2 O 3 and CuI with HL at different temperatures under hydrothermal conditions. All the complexes are characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1–3 all construct from dimeric (Ln 2 ) and (Cu 2 ) units and exhibit two types of the structural features: 1 is a two-dimensional layer, 2–3 are three-dimensional frameworks. Interestingly, the in situ formation of the BPDC ligand is found in the structure of 3. The distinct architectures of these complexes indicated that the reaction temperature plays an important role in the formation of higher dimensional coordination polymers. - Graphical abstract: By hydrothermal reaction of lanthanide oxide, copper halide, and 4-pyridin-3-yl-benzoic ligand at different temperatures, a series of 1-D to 3-D 3d–4f coordination polymers, namely [ErL 3 (H 2 O) 2 ][CuI], [Er 2 L 6 (H 2 O)][Cu 2 I 2 ], [ErL 3 ][CuI], and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ], have been made, respectively. - Highlights: • Three novel heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid have been hydrothermally synthesized. • Mixed dinuclear motifs of (Ln 2 ) and (Cu 2 ) serve as secondary building units to generate 2-D layer and 3-D frameworks. • It is proved that higher temperature is apt to permit construction of high dimensional architectures

N-[5-Methyl-2-(2-nitrophenyl-4-oxo-1,3-thiazolidin-3-yl]pyridine-3-carboxamide monohydrate

Directory of Open Access Journals (Sweden)

Mehmet Akkurt

2011-02-01

Full Text Available In the title compound, C16H14N4O4S·H2O, the benzene and pyridine rings make a dihedral angle of 85.8 (1°. Both enantiomers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C5 of the thiazolidine ring were therefore refined with common site-occupation factors of 0.531 (9 and 0.469 (9, respectively, for each stereoisomer. In the crystal, intermolecular N—H...O, O—H...O and O—H...N hydrogen bonds link the molecules, forming a three-dimensional supramolecular network. The crystal structure further shows π–π stacking interactions [centroid–centroid distance = 3.5063 (13 Å] between the pyridine rings.

Investigation of the Effect of Plasma Polymerized Siloxane Coating for Enzyme Immobilization and Microfluidic Device Conception

Directory of Open Access Journals (Sweden)

Kalim Belhacene

2016-12-01

Full Text Available This paper describes the impact of a physical immobilization methodology, using plasma polymerized 1,1,3,3, tetramethyldisiloxane, on the catalytic performance of β-galactosidase from Aspergillus oryzae in a microfluidic device. The β-galactosidase was immobilized by a polymer coating grown by Plasma Enhanced Chemical Vapor Deposition (PEVCD. Combined with a microchannel patterned in the silicone, a microreactor was obtained with which the diffusion through the plasma polymerized layer and the hydrolysis of a synthetic substrate, the resorufin-β-d-galactopyranoside, were studied. A study of the efficiency of the immobilization procedure was investigated after several uses and kinetic parameters of immobilized β-galactosidase were calculated and compared with those of soluble enzyme. Simulation and a modelling approach were also initiated to understand phenomena that influenced enzyme behavior in the physical immobilization method. Thus, the catalytic performances of immobilized enzymes were directly influenced by immobilization conditions and particularly by the diffusion behavior and availability of substrate molecules in the enzyme microenvironment.

Direct 13C-1H coupling constants in the vinyl group of 1-vinylpyrazoles

International Nuclear Information System (INIS)

Afonin, A.V.; Voronov, V.K.; Es'kova, L.A.; Domnina, E.S.; Petrova, E.V.; Zasyad'ko, O.V.

1987-01-01

In a continuation of a study of the rotational isomerism of 1-vinylpyrazoles, they studied the direct 13 C- 1 H coupling constants in the vinyl group of 1-vinylpyrazole, 1-vinyl-4-bromopyrazole, 1-vinyl-3-methylpyrazole, 1-vinyl-5-methylpyrazole, 1-vinyl-3,5-dimethylpyrazole, and 1-vinyl-4-nitro-3,5-dimethylpyrazole. The 13 C- 1 H direct coupling constants in the vinyl group of 1-vinylpyrazoles are stereo-specific and vary with change in the conformer ratio

Development of Nano-Particles Within Polymeric Materials Prepared by Gamma Radiation and their Possible Practical Applications

Energy Technology Data Exchange (ETDEWEB)

Hegazy, E. S.A.; Ali, A. E.; AbdEl-Rehim, H.; Mohammady, M.; Abdel Aal, A. S. [National Center for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

2009-07-01

Nanoparticles can be used in biomedical applications, where they facilitate laboratory diagnostics, or in medical drug targeting nanoparticles based on a core consisting of iron oxides that can be targeted through external magnets. Polyvinyl alcohol/Polyacrylic acid nanoparticles were prepared using gamma rays. The prepared PVA/AAc nano copolymers were treated with Fe{sup 2+}/ Fe{sup 3+} solution followed by ammonia solution to obtain PVA/AAc-Fe{sub 3}O{sub 4} nanoparticle ferrogel. Characterization of the PVA/AAc-Fe{sub 3}O{sub 4} nanoparticle ferrogel was carried out using XRD, TGA, DSc , TEM and AFM. The use of magnetic field sensitive nano-ferrogels as a drug carrier was investigated. It was found that the release of drug in absence of the effect of magnetic field is mostly slow than that under the influence of magnetic field. On the other hand, development of nanoparticles within radiation grafted polymeric surfaces using electroless plating technique was investigated. Surface modification of polypropylene films (PP) was carried out via radiation induced graft copolymerization of 4-vinyl pyridine (4VP) and acrylamide (AAm) to enhance the adhesion ability of the PP surface for electroless deposition of copper. The produced grafted films were characterized by studying their FTIR and thermal stability. The prepared grafted films were copper-plated by electroless deposition using the Pd as a catalyst to initiate the redox reaction. The influences of catalytic activation method parameters on the plating rate have been studied. The electrical characteristics of the copper plated films in comparison with grafted films were studied. The results showed the high adhesion of the deposited copper film to the grafted PP film as well as high electrical conductivity. (author)

CuI nanoparticles as new, efficient and reusable catalyst for the one-pot synthesis of 1,4-dihydro pyridines

International Nuclear Information System (INIS)

Safaeighomi, Javad; Ziarati, Abolfazl; Teymuri, Raheleh

2012-01-01

A simple one-pot synthesis of two derivatives of 1,4-dihydro pyridines has been described under reflux conditions using copper iodide nanoparticles (CuI NPs) as a catalyst in high yields. This method demonstrated four-component coupling reactions of aldehydes and ammonium acetate via two pathways. In one route, the reaction was performed using 2 eq ethyl acetoacetate while in the other one 1 eq ethyl acetoacetate and 1 eq malononitrile were used. The CuI NPs was reused and recycled without any loss of activity and product yield. It is noteworthy to state that wide range of the 1,4-dihydro pyridines have attracted large interest due to pharmacological and biological activities

Synthesis, spectroscopic and electrochemical properties of mononuclear and dinuclear bis(bipy)ruthenium(II) complexes containing dimethoxyphenyl(pyridin-2-yl)-1,2,4-triazole ligands

NARCIS (Netherlands)

Passaniti, Paolo; Browne, Wesley R.; Lynch, Fiona C.; Hughes, Donal; Nieuwenhuyzen, Mark; James, Paraic; Maestri, Mauro; Vos, Johannes G.

2002-01-01

The ligands HL1 and H(2)L2 and the complexes [Ru(bipy)(2)L1]PF6.2H(2)O 1, [(Ru(bipy)(2))(2)L2](PF6)(2).7H(2)O 2, {where HL1 = 3-(2', 5'-dimethoxyphenyl)-5-(pyridin-2"-yl)- 1H-1,2,4-triazole, H(2)L2 = 1,4- bis(5'-(pyridin-2"-yl)- 1'H- 1', 2', 4'-triazol-3'-yl)- 2,5-dimethoxybenzene and bipy =

Preparation, Characterization and Permeation Behavior of Poly(methyl acrylate-Poly(dimethyl siloxane-Poly(methyl acrylate Block Copolymer/Poly(vinyl acetate Blend Membranes

Directory of Open Access Journals (Sweden)

Mohammad Ali Semsarzadeh

2015-03-01

Full Text Available Structure of polymeric materials is of the most important factors in determination of the characteristics and properties of the membranes. Various research and developments on polymeric membranes confirm the direct correlation between structure-properties of polymeric membranes. In this research, the structural outcome of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate/poly(vinyl acetate blend membranes and its relationship with gas permeation behavior of the blends were investigated. The flexible block copolymer of poly(methyl acrylate-poly(dimethyl siloxane-poly(methyl acrylate (PMA-PDMS-PMA was synthesized via atom transfer radical polymerization. Morphology and chemical structure of the synthesized block copolymer was investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, X-ray diffraction analysis, differential scanning calorimetry and scanning electron microscopy. Blend membranes of PMA-PDMS-PMA and poly(vinyl acetate (PVAc were prepared by solution casting method in different compositions. By adding poly(vinyl acetate to PMA-PDMS-PMA block copolymer, the selectivity of the membranes for carbon dioxide/methane pair gases were increased by 55%. Fractional free volume (an indication of chain packing efficiency in blend membranes and dielectric constant (an indication of the molar volume and molar polarization of the blend membranes were obtained as the factors reflected the microstructural effect of PMA-PDMS-PMA and PVAc blend membranes. The efforts were directed toward expressing more precise structure-properties relationship of PMA-PDMS-PMA/PVAc blend membranes. The experimental permeability values of the blend membranes reported in this research were compared with the modified logarithmic model. The modified logarithmic model was evaluated for other blend membranes.

Optical characterization of composite layers prepared by plasma polymerization

International Nuclear Information System (INIS)

Radeva, E; Hikov, T; Mitev, D; Pramatarova, L; Stroescu, H; Nicolescu, M; Gartner, M; Presker, R

2016-01-01

Thin composite layers from polymer/nanoparticles (Ag-nanoparticles and detonation nanodiamonds) were prepared by plasma polymerization process on the base of hexamethyldisiloxane. The variation of the layer composition was achieved by changing the type of nanoparticles. The optical measurement techniques used were UV-VIS-NIR ellipsometry (SE), Fourier-transformed infrared spectroscopy (FTIR) and Raman spectroscopy. The values of the refractive index determined are in the range 1.30 to 1.42. All samples are transparent with transmission between 85-95% and very smooth. The change in Raman and FTIR spectra of the composites verify the expected bonding between polymer and diamond nanoparticles due to the penetration of the fillers in the polymer matrix. The comparison of the spectra of the corresponding NH3 plasma treated composites revealed that the composite surface becomes more hydrophilic. The obtained results indicate that preparation of layers with desired compositions is possible at a precise control of the detonation nanodiamond materials. (paper)

A Thieno[2,3-b]pyridine-Flanked Diketopyrrolopyrrole Polymer as an n-Type Polymer Semiconductor for All-Polymer Solar Cells and Organic Field-Effect Transistors

KAUST Repository

Chen, Hung-Yang

2017-12-28

A novel fused heterocycle-flanked diketopyrrolopyrrole (DPP) monomer, thieno[2,3-b]pyridine diketopyrrolopyrrole (TPDPP), was designed and synthesized. When copolymerized with 3,4-difluorothiophene using Stille coupling polymerization, the new polymer pTPDPP-TF possesses a highly planar conjugated polymer backbone due to the fused thieno[2,3-b]pyridine flanking unit that effectively alleviates the steric hindrance with both the central DPP core and the 3,4-difluorothiophene repeat unit. This new polymer exhibits a high electron affinity (EA) of −4.1 eV and was successfully utilized as an n-type polymer semiconductor for applications in organic field-effect transistors (OFETs) and all polymer solar cells. A promising n-type charge carrier mobility of 0.1 cm2 V–1 s–1 was obtained in bottom-contact, top-gate OFETs, and a power conversion efficiency (PCE) of 2.72% with a high open-circuit voltage (VOC) of 1.04 V was achieved for all polymer solar cells using PTB7-Th as the polymer donor.

A Thieno[2,3-b]pyridine-Flanked Diketopyrrolopyrrole Polymer as an n-Type Polymer Semiconductor for All-Polymer Solar Cells and Organic Field-Effect Transistors

KAUST Repository

Chen, Hung-Yang; Nikolka, Mark; Wadsworth, Andrew; Yue, Wan; Onwubiko, Ada; Xiao, Mingfei; White, Andrew J. P.; Baran, Derya; Sirringhaus, Henning; McCulloch, Iain

2017-01-01

A novel fused heterocycle-flanked diketopyrrolopyrrole (DPP) monomer, thieno[2,3-b]pyridine diketopyrrolopyrrole (TPDPP), was designed and synthesized. When copolymerized with 3,4-difluorothiophene using Stille coupling polymerization, the new polymer pTPDPP-TF possesses a highly planar conjugated polymer backbone due to the fused thieno[2,3-b]pyridine flanking unit that effectively alleviates the steric hindrance with both the central DPP core and the 3,4-difluorothiophene repeat unit. This new polymer exhibits a high electron affinity (EA) of −4.1 eV and was successfully utilized as an n-type polymer semiconductor for applications in organic field-effect transistors (OFETs) and all polymer solar cells. A promising n-type charge carrier mobility of 0.1 cm2 V–1 s–1 was obtained in bottom-contact, top-gate OFETs, and a power conversion efficiency (PCE) of 2.72% with a high open-circuit voltage (VOC) of 1.04 V was achieved for all polymer solar cells using PTB7-Th as the polymer donor.

Formation of mono- and multilayers of metal complexes of 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine

NARCIS (Netherlands)

Werkman, P J; Wilms, H; Wieringa, R H; Schouten, A J

1998-01-01

The monolayer properties of the amphiphile, 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine have been studied by measuring the surface pressure-area isotherms. The amphiphile forms stable monolayers at the air-water interface and protonation of the monolayers occurs at pH values of 3.00 or lower.

Synthesis of 2-(5-Nitropyrid-2-yl-3-(4-substitutedphenylaminoisoxazol-5(2H-ones and Their Rearrangements to Imidazo[1,2-a]- pyridines and Indoles with Triethylamine

Directory of Open Access Journals (Sweden)

K. Akbari Dilmaghani

2002-12-01

Full Text Available 3-(4-Substitutedphenylaminoisoxazol-5(2H-ones, substituted on nitrogen with a nitropyridine group, react with triethylamine to give imidazo[1,2-a]pyridines and indoles. With 4-bromophenyl and 4-methylphenyl group substituents only imidazopyridines are formed, but the 4-methoxyphenyl derivative gave a 3:1 mixture of the corresponding imidazo[1,2-a]pyridine and 2-pyridylaminoindole, respectively.

Pyrolysis of methane in flowing microwave plasma. Pt. 1, 2

International Nuclear Information System (INIS)

Carmi, U.; Inor, A.A.; Avni, R.; Nickel, H.

1978-04-01

The flowing microwave (2.45 G Hz) plasmas of methane and methane-argon mixtures were analyzed by the electrical double floating probe system (DFPS), along the flow stream. The measured electric variables of the microwave plasma were: current, current density, electric field strength, electron temperature, positive ion and electron concentrations. They indicate an irreversible process, of the polymerization of CH 4 and CH 4 +Ar mixtures, taking place in the plasma. The polymerization process reaches its maximum 'down stream'. after the position of the microwave cavity. The polymerization was correlated to the concentration of ions and electrons in the plasma. (orig.) [de

Effects of polymerization degree on recovery behavior of PVA/PVP hydrogels as potential articular cartilage prosthesis after fatigue test

Directory of Open Access Journals (Sweden)

Y. Shi

2016-02-01

Full Text Available Poly (vinyl alcohol/poly (vinyl pyrrolidone (PVA/PVP hydrogels with various polymerization degrees of PVA were synthesized by a repeated freezing-thawing method. The influence of polymerization degree on microstructure, water content, friction coefficient, compressive fatigue and recovery properties of PVA/PVP hydrogels were investigated. The results showed that higher polymerization degree resulted in larger compressive modulus and lower friction coefficient. The fatigue behaviors of PVA/PVP hydrogels were evaluated under sinusoidal compressive loading from 200 to 800 N at 5 Hz for up to 50 000 cycles. The unconfined uniaxial compressive tests of PVA/PVP hydrogels were performed before and after fatigue test. During the fatigue test, the height of the hydrogel rapidly decreased at first and gradually became stable with loading cycles. The compressive tangent modulus measured 0 h after fatigue was significantly larger than the values obtained before test, and then the modulus recovered to its original level for 48 h after test. However, the geometry of hydrogels could not return to the original level due to the creep effects. PVA/PVP hydrogels prepared with lower polymerization degree showed better recovery capability than that prepared with high polymerization degree.

The effects of water absorption on an ester vinyl resin system

Directory of Open Access Journals (Sweden)

Ledjane Lima Sobrinho

2009-09-01

Full Text Available Derakene is a vinyl ester resin largely employed as matrix for polymeric based composite systems. In this work, the performance of such polymeric system was evaluated considering the effect of hygrothermal aging. The mechanical and thermal properties were examined for the processed material before and after ageing in water at 60 ºC for a maximum period of 64 days. Both analyses indicated the occurrence of post cure of the system after 16 days due to exposition at 60 ºC in water, which was also confirmed by analyses in samples with post cure treatment. Moreover, it was observed plasticizing of resin after 36 and 64 days of ageing. Micro structural and fracture surface analyses were carried out in order to characterize the samples. The appearance of surface voids was also observed.

Ultrasmooth plasma polymerized coatings for laser fusion targets

International Nuclear Information System (INIS)

Letts, S.A.; Myers, D.W.; Witt, L.A.

1980-01-01

Coatings for laser fusion were deposited up to 135μm thick by plasma polymerization onto 140 μm diameter DT filled glass microspheres. Ultrasmooth surfaces (no defect higher than 0.1 μm) were achieved by eliminating particulate contamination. Process generated particles were eliminated by determining the optimum operating conditions of power (20 watts), gas flow (0.3 sccm trans-2-butene, 10.0 sccm hydrogen), and pressure (75 millitorr), and maintaining these conditions through feedback control. From a study of coating defects grown over known surface irregularities, a quantitative relationship between irregularity size, film thickness, and defect size was determined. This relationship was used to set standards for the maximum microshell surface irregularity tolerable in the production of hydrocarbon or fluorocarbon coated laser fusion targets

A study on poly (N-vinyl-2-pyrrolidone covalently bonded NiTi surface for inhibiting protein adsorption

Directory of Open Access Journals (Sweden)

Hongyan Yu

2016-12-01

Full Text Available Near equiatomic NiTi alloys have been extensively applied as biomaterials owing to its unique shape memory effect, superelasticity and biocompatibility. It has been demonstrated that surfaces capable of preventing plasma protein adsorption could reduce the reactivity of biomaterials with human blood. This motivated a lot of researches on the surface modification of NiTi alloy. In the present work, following heat and alkaline treatment and silanization by trichlorovinylsilane (TCVS, coating of poly (N-vinyl-2-pyrrolidone (PVP was produced on the NiTi alloy by gamma ray induced chemical bonding. The structures and properties of modified NiTi were characterized and in vitro biocompatibility of plasma protein adsorption was investigated. The results indicated that heat treatment at 823 K for 1 h could result in the formation of a protective TiO2 layer with “Ni-free” zone on NiTi surface. It was found that PVP was covalently bonded on NiTi surface to create a hydrophilic layer for inhibiting protein adsorption on the surface. The present work offers a green approach to introduce a bioorganic surface on metal and other polymeric or inorganic substrates by gamma irradiation.

Preparation and characterization of poly(vinyl sulfone)- and poly(vinylidene fluoride)-based electrolytes

Energy Technology Data Exchange (ETDEWEB)

Choe, H.S.; Giaccai, J.; Alamgir, M.; Abraham, K.M. [EIC Labs., Inc., Norwood, MA (United States)

1995-10-01

A novel group of polymer electrolytes based on poly(vinyl sulfone) (PVS) and poly(vinylidene fluoride) (PVdF) polymers, plasticized with highly conductive solutions of LiClO{sub 4}, LiN(CF{sub 3}SO{sub 2}){sub 2} or LiAsF{sub 6} dissolved in ethylene carbonate, propylene carbonate, sulfolane, or mixtures thereof, was prepared via in situ photopolymerization and solution casting, respectively. The polymer electrolytes were characterized from conductivity and cyclic voltammetry data. It was found that solutions of Li salts in the vinyl sulfone monomer were highly conductive at room temperature with conductivities of 0.6 to 1.3 x 10{sup -3} {Omega}{sup -1}cm{sup -1} at 30{sup o}C, but the conductivities decreased by about 10{sup 3} times on polymerizing. Conversely, the conductivities increased by about 10{sup 2} to 10{sup 4} times on incorporating plasticizing solvents into the solid polymer electrolytes, suggesting that ionic mobility is the primary factor affecting the conductivities of solid polymer electrolytes. The highest conductivity exhibited by PVS-based electrolyte was 3.74 x 10{sup -4} {Omega}{sup -1}cm{sup -1} and that by PVdF-based electrolyte was 1.74 x 10{sup -3} {Omega}{sup -1}cm{sup -1}, at 30{sup o}C. The PVS-based electrolytes were found to be stable to oxidation up to potentials ranging between 4.5 and 4.8 V, while the stable potential limits for PVdF-based electrolytes were between 3.9 and 4.3 V vs. Li{sup +}/Li. (author)

6-Bromo-1,3-di-2-propynyl-1H-imidazo[4,5-b]pyridin-2(3H-one

Directory of Open Access Journals (Sweden)

S. Dahmani

2010-04-01

Full Text Available The room-temperature reaction of propargyl bromide and 6-bromo-1,3-dihydroimidazo[4,5-b]pyridin-2-one in dimethylformamide yields the title compound, C12H8BrN3O, which features nitrogen-bound propynyl substituents. The imidazopyridine fused ring is almost planar (r.m.s. deviation = 0.011 Å; the propynyl chains point in opposite directions relative to the fused ring. One acetylenic H atom is hydrogen bonded to the carbonyl O atom of an inversion-related molecule, forming a dimer; adjacent dimers are linked by a second acetylene–pyridine C—H...N interaction, forming a layer motif.

2-Amino-1-methyl-6-(5-hydroxy-)phenylimidazo[4,5-b]pyridine (5-OH-PhIP), a biomarker for the genotoxic dose of the heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)

DEFF Research Database (Denmark)

Frandsen, H; Frederiksen, H; Alexander, J

2002-01-01

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. PhIP is metabolically activated by CYP P450 mediated N-hydroxylation followed by phase II esterification. The ultimate mutagenic metabolite reacts with DNA...

Vinyl Record

DEFF Research Database (Denmark)

Bartmanski, Dominik; Woodward, Ian

2018-01-01

. This relational process means that both the material affordances and entanglements of vinyl allow us to feel, handle, experience, project, and share its iconicity. The materially mediated meanings of vinyl enabled it to retain currency in independent and collector’s markets and thus resist the planned......In this paper, we use the case of the vinyl record to show that iconic objects become meaningful via a dual process. First, they offer immersive engagements which structure user interpretations through various material experiences of handling, use, and extension. Second, they always work via...

Kinetics of Vinyl Polymerization of Methyl Methacrylate Initiated by Ce(IV-Vanillin Redox System

Directory of Open Access Journals (Sweden)

M. Palanivelu

2012-01-01

Full Text Available The kinetics of polymerization of methyl methacrylate initiated by Ce(IV-Vanillin redox system was studied in aqueous solution of sulfuric acid at 40°C. The rate of polymerization (Rp and the reaction orders with respect to monomer, initiator and ligand have been determined and found to be 1.5, 0.5 and 0.5 respectively. The effect of concentration of sulfuric acid on the polymerization was also studied. The rate of polymerization was found to increase with increasing temperature 30–60°C and decreases at higher temperature (>60°C. The overall activation energy (Ea was found to be 36.7 kJ/mol. A suitable kinetic scheme has been proposed.

Pre-treatment of pyridine wastewater by new cathodic-anodic-electrolysis packing.

Science.gov (United States)

Jin, Yang; Yue, Qinyan; Yang, Kunlun; Wu, Suqing; Li, Shengjie; Gao, Baoyu; Gao, Yuan

2018-01-01

A novel cathodic-anodic-electrolysis packing (CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4'-diamino-2,2'-disulfonic acid (DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of pH, hydraulic retention time (HRT), the air-liquid ratio (A/L) and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon (TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921kg/m 3 , 1086kg/m 3 , 25% and 29.89m 2 /g, respectively; the removal of TOC and pyridine could reach 50% and 58% at the optimal experimental conditions (pH=3, HRT=8hr, A/L=2). Notably, the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. Copyright © 2017. Published by Elsevier B.V.

Fabrication of thermo-responsive cotton fabrics using poly(vinyl caprolactam-co-hydroxyethyl acrylamide) copolymer.

Science.gov (United States)

Xiao, Min; González, Edurne; Monterroza, Alexis Martell; Frey, Margaret

2017-10-15

A thermo-responsive polymer with hydrophilic to hydrophobic transition behavior, poly(vinyl caprolactam-co-hydroxyethyl acrylamide) P(VCL-co-HEAA), was prepared by copolymerization of vinyl caprolactam and N-hydroxyethyl acrylamide via free radical solution polymerization. The resulting copolymer was characterized by Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The lower critical solution temperature (LCST) of P(VCL-co-HEAA) was determined at 34.5°C. This thermo-responsive polymer was then grafted onto cotton fabrics using 1,2,3,4-butanetetracarboxylic acid (BTCA) as crosslinker and sodium hypophosphite (SHP) as catalyst. FTIR and energy dispersive X-ray spectroscopy (EDS) studies confirmed the successful grafting reaction. The modified cotton fabric exhibited thermo-responsive behavior as evidenced by water vapor permeability measurement confirming decreased permeability at elevated temperature. This is the first demonstration that a PVCL based copolymer is grafted to cotton fabrics. This study provides a new thermo-responsive polymer for fabrication of smart cotton fabrics with thermally switchable hydrophilicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stability study of polyacrylic acid films plasma-polymerized on polypropylene substrates at medium pressure

Energy Technology Data Exchange (ETDEWEB)

Morent, Rino, E-mail: Rino.Morent@Ugent.be [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); De Geyter, Nathalie [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Trentesaux, Martine; Gengembre, Leon [Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, Universite des Sciences et Technologies de Lille, Bat. C3, Cite Scientifique, 59655 Villeneuve d' Ascq (France); Dubruel, Peter [Department of Organic Chemistry, Polymer Chemistry and Biomaterials Research Group, Faculty of Sciences, Ghent University, Krijgslaan 281, 9000 Ghent (Belgium); Leys, Christophe [Department of Applied Physics, Research Unit Plasma Technology, Faculty of Engineering, Ghent University, Jozef Plateaustraat 22, 9000 Ghent (Belgium); Payen, Edmond [Unite de Catalyse et Chimie du Solide, UMR CNRS 8181, Universite des Sciences et Technologies de Lille, Bat. C3, Cite Scientifique, 59655 Villeneuve d' Ascq (France)

2010-11-01

Plasma polymerization of acrylic acid has become an interesting research subject, since these coatings are expected to be beneficial for biomedical applications due to their high surface density of carboxylic acid functional groups. However, the application of these monomers is counteracted by their low stability in humid environments, since a high stability is a required characteristic for almost any biological application. The present work investigates whether it is possible to obtain stable deposits with a high retention of carboxylic acid functions by performing plasma polymerization on polypropylene substrates with a dielectric barrier discharge operating at medium pressure. In order to obtain coatings with the desired properties, the plasma parameters need to be optimized. Therefore, in this paper, the influence of discharge power and location of the substrate in the discharge chamber is examined in detail. The properties of the deposited films are studied using contact angle measurements, X-ray photoelectron spectroscopy, atomic force microscopy and Fourier transform infrared spectroscopy. Moreover, to determine whether the obtained deposits are soluble in water, the coatings are once again analyzed after rinsing in water. This paper will clearly show that stable COOH-rich surfaces can be obtained at high discharge power and close to the monomer inlet, which might open perspectives for future biomedical applications.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate

Directory of Open Access Journals (Sweden)

Paulina Arellanes-Lozada

2014-08-01

Full Text Available Compounds of poly(ionic liquids (PILs, derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium (PImC12, poly(1-vinyl-3-octylimidazolium (PImC8 and poly(1-vinyl-3-butylimidazolium (PImC4 hexafluorophosphate were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4 by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4 to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

Crosslinked poly(vinyl alcohol hydrogels for wound dressing applications: A review of remarkably blended polymers

Directory of Open Access Journals (Sweden)

Elbadawy A. Kamoun

2015-01-01

Full Text Available A series of excellent poly(vinyl alcohol (PVA/polymers blend hydrogel were reviewed using different crosslinking types to obtain proper polymeric dressing materials, which have satisfied biocompatibility and sufficient mechanical properties. The importance of biodegradable–biocompatible synthetic polymers such as PVA, natural polymers such as alginate, starch, and chitosan or their derivatives has grown significantly over the last two decades due to their renewable and desirable biological properties. The properties of these polymers for pharmaceutical and biomedical application needs have attracted much attention. Thus, a considered proportion of the population need those polymeric medical applications for drug delivery, wound dressing, artificial cartilage materials, and other medical purposes, where the pressure on alternative polymeric devices in all countries became substantial. The review explores different polymers which have been blended previously in the literature with PVA as wound dressing blended with other polymeric materials, showing the feasibility, property change, and purpose which are behind the blending process with PVA.

CHEMOENZYMATIC SYNTHESIS OF BIODEGRADABLE POLY(1′-O-VINYLADIPOYL-SUCROSE)

Institute of Scientific and Technical Information of China (English)

Des-hui Lu; Qi Wu; Xian-fu Lin

2002-01-01

A novel polymer containing the sucrose group was synthesized by radical polymerization from an enzymaticallyprepared monomer, 1′-O-vinyladipoyl-sucrose (VAS). Transesterification reaction of sucrose with divinyl adipate inanhydrous pyridine catalyzed by an alkaline protease from Bacillus subtilis at 60℃ for 7 days gave VAS (yield 55%) withoutany blocking/deblocking steps. The vinyl sucrose ester could be polymerized with potassium persulfate and H2O2 as initiatorto give poly(1′-O-vinyladipoyl-sucrose) with Mn ＝ 33,000 and Mw ＝ 53,200, Mw/Mn ＝ 1.61. The polymer was biodegradable.After 6 days in aqueous buffer (pH 7), this alkaline protease could degrade poly(1′-O-vinyladipoyl-sucrose) to Mn of ca.1080, Mw/Mn ＝ 3.30 (37℃), and Mn of ca. 5200, Mw/Mn ＝ 2.44 (4℃). The polymer containing the sucrose branch would be afunctional material in various application fields.

Surface modification of polymeric substrates by plasma-based ion implantation

Science.gov (United States)

Okuji, S.; Sekiya, M.; Nakabayashi, M.; Endo, H.; Sakudo, N.; Nagai, K.

2006-01-01

Plasma-based ion implantation (PBII) as a tool for polymer modification is studied. Polymeric films have good performances for flexible use, such as food packaging or electronic devices. Compared with inorganic rigid materials, polymers generally have large permeability for gases and moisture, which causes packaged contents and devices to degrade. In order to add a barrier function, surface of polymeric films are modified by PBII. One of the advantageous features of this method over deposition is that the modified surface does not have peeling problem. Besides, micro-cracks due to mechanical stress in the modified layer can be decreased. From the standpoint of mass production, conventional ion implantation that needs low-pressure environment of less than 10-3 Pa is not suitable for continuous large-area processing, while PBII works at rather higher pressure of several Pa. In terms of issues mentioned above, PBII is one of the most expected techniques for modification on flexible substrates. However, the mechanism how the barrier function appears by ion implantation is not well explained so far. In this study, various kinds of polymeric films, including polyethyleneterephthalate (PET), are modified by PBII and their barrier characteristics that depend on the ion dose are evaluated. In order to investigate correlations of the barrier function with implanted ions, modified surface is analyzed with X-ray photoelectron spectroscopy (XPS). It is assumed that the diffusion and sorption coefficients are changed by ion implantation, resulting in higher barrier function.

Surface modification of polymeric substrates by plasma-based ion implantation

International Nuclear Information System (INIS)

Okuji, S.; Sekiya, M.; Nakabayashi, M.; Endo, H.; Sakudo, N.; Nagai, K.

2006-01-01

Plasma-based ion implantation (PBII) as a tool for polymer modification is studied. Polymeric films have good performances for flexible use, such as food packaging or electronic devices. Compared with inorganic rigid materials, polymers generally have large permeability for gases and moisture, which causes packaged contents and devices to degrade. In order to add a barrier function, surface of polymeric films are modified by PBII. One of the advantageous features of this method over deposition is that the modified surface does not have peeling problem. Besides, micro-cracks due to mechanical stress in the modified layer can be decreased. From the standpoint of mass production, conventional ion implantation that needs low-pressure environment of less than 10 -3 Pa is not suitable for continuous large-area processing, while PBII works at rather higher pressure of several Pa. In terms of issues mentioned above, PBII is one of the most expected techniques for modification on flexible substrates. However, the mechanism how the barrier function appears by ion implantation is not well explained so far. In this study, various kinds of polymeric films, including polyethyleneterephthalate (PET), are modified by PBII and their barrier characteristics that depend on the ion dose are evaluated. In order to investigate correlations of the barrier function with implanted ions, modified surface is analyzed with X-ray photoelectron spectroscopy (XPS). It is assumed that the diffusion and sorption coefficients are changed by ion implantation, resulting in higher barrier function

Synthesis and Characterization of Nanofibrous Polyaniline Thin Film Prepared by Novel Atmospheric Pressure Plasma Polymerization Technique.

Science.gov (United States)

Park, Choon-Sang; Kim, Dong Ha; Shin, Bhum Jae; Tae, Heung-Sik

2016-01-11

This work presents a study on the preparation of plasma-polymerized aniline (pPANI) nanofibers and nanoparticles by an intense plasma cloud type atmospheric pressure plasma jets (iPC-APPJ) device with a single bundle of three glass tubes. The nano size polymer was obtained at a sinusoidal wave with a peak value of 8 kV and a frequency of 26 kHz under ambient air. Discharge currents, photo-sensor amplifier, and optical emission spectrometer (OES) techniques were used to analyze the plasma produced from the iPC-APPJ device. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), gas chromatography-mass spectrometry (GC-MS), and gel permeation chromatography (GPC) techniques were used to analyze the pPANI. FE-SEM and TEM results show that pPANI has nanofibers, nanoparticles morphology, and polycrystalline characteristics. The FT-IR and GC-MS analysis show the characteristic polyaniline peaks with evidence that some quinone and benzene rings are broken by the discharge energy. GPC results show that pPANI has high molecular weight ( M w ), about 533 kDa with 1.9 polydispersity index (PDI). This study contributes to a better understanding on the novel growth process and synthesis of uniform polyaniline nanofibers and nanoparticles with high molecular weights using the simple atmospheric pressure plasma polymerization technique.

Synthesis and Characterization of Nanofibrous Polyaniline Thin Film Prepared by Novel Atmospheric Pressure Plasma Polymerization Technique

Directory of Open Access Journals (Sweden)

Choon-Sang Park

2016-01-01

Full Text Available This work presents a study on the preparation of plasma-polymerized aniline (pPANI nanofibers and nanoparticles by an intense plasma cloud type atmospheric pressure plasma jets (iPC-APPJ device with a single bundle of three glass tubes. The nano size polymer was obtained at a sinusoidal wave with a peak value of 8 kV and a frequency of 26 kHz under ambient air. Discharge currents, photo-sensor amplifier, and optical emission spectrometer (OES techniques were used to analyze the plasma produced from the iPC-APPJ device. Field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FT-IR, gas chromatography-mass spectrometry (GC-MS, and gel permeation chromatography (GPC techniques were used to analyze the pPANI. FE-SEM and TEM results show that pPANI has nanofibers, nanoparticles morphology, and polycrystalline characteristics. The FT-IR and GC-MS analysis show the characteristic polyaniline peaks with evidence that some quinone and benzene rings are broken by the discharge energy. GPC results show that pPANI has high molecular weight (Mw, about 533 kDa with 1.9 polydispersity index (PDI. This study contributes to a better understanding on the novel growth process and synthesis of uniform polyaniline nanofibers and nanoparticles with high molecular weights using the simple atmospheric pressure plasma polymerization technique.

Crystal structures of N2,N3,N5,N6-tetrakis(pyridin-2-ylmethylpyrazine-2,3,5,6-tetracarboxamide and N2,N3,N5,N6-tetrakis(pyridin-4-ylmethylpyrazine-2,3,5,6-tetracarboxamide

Directory of Open Access Journals (Sweden)

Dilovan S. Cati

2017-02-01

Full Text Available The title compounds, C32H28N10O4· unknown solvent, (I, and C32H28N10O4, (II, are pyrazine-2,3,5,6-tetracarboxamide derivatives. In (I, the substituents are (pyridin-2-ylmethylcarboxamide, while in (II, the substituents are (pyridin-4-ylmethylcarboxamide. Both compounds crystallize in the monoclinic space group P21/n, with Z′ = 1 for (I, and Z′ = 0.5 for (II. The whole molecule of (II is generated by inversion symmetry, the pyrazine ring being situated about a center of inversion. In (I, the four pyridine rings are inclined to the pyrazine ring by 83.9 (2, 82.16 (18, 82.73 (19 and 17.65 (19°. This last dihedral angle involves a pyridine ring that is linked to the adjacent carboxamide O atom by an intramolecular C—H...O hydrogen bond. In compound (II, the unique pyridine rings are inclined to the pyrazine ring by 33.3 (3 and 81.71 (10°. There are two symmetrical intramolecular C—H...O hydrogen bonds present in (II. In the crystal of (I, molecules are linked by N—H...O and N—H...N hydrogen bonds, forming layers parallel to (10-1. The layers are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional framework. In the crystal of (II, molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [010] direction. The chains are linked by a weaker N—H...N hydrogen bond, forming layers parallel to the (101 plane, which are in turn linked by C—H...O hydrogen bonds, forming a three-dimensional structure. In the crystal of compound (I, a region of disordered electron density was treated with the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18]. Their contribution was not taken into account during refinement. In compound (II, one of the pyridine rings is positionally disordered, and the refined occupancy ratio for the disordered Car—Car—Npy atoms is 0.58 (3:0.42 (3.

5-(4-Ethoxyphenyl-3-(pyridin-2-yl-4,5-dihydro-1H-pyrazole-1-carbothioamide

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2012-03-01

Full Text Available In the title compound, C17H18N4OS, a pyrazoline derivative, the pyrazoline ring adopts an envelope conformation with the C atom bonded to the benzene ring as the flap atom. The dihedral angle between the pyridine and benzene rings is 80.50 (6°. The ethoxyphenyl group is approximately planar, with an r.m.s. deviation of 0.0238 (1 Å for the nine non-H atoms. In the crystal, molecules are linked by N—H...O and N—H...S hydrogen bonds into a tape along the b axis. Weak C—H...N and C—H...π interactions are also observed.

Poly[dibromidobis[μ-1-(pyridin-4-ylmethyl-1H-1,2,4-triazole-κ2N:N′]cadmium

Directory of Open Access Journals (Sweden)

Xiu-Zhi Xu

2011-02-01

Full Text Available The title coordination polymer, [CdBr2(C8H8N42]n, arose from a layer-separated diffusion synthesis at room temperature. The title compound is isotypic with the I and Cl analogues. The Cd atom, located on an inversion center, is coordinated by two bromide ions and four N atoms (two from triazole rings and two from pyridyl rings in a distorted trans-CdBr2N4 octahedral arrangement. The bridging 1-(4-pyridylmethyl-1H-1,2,4-triazole ligands are twisted [dihedral angle between the triazole and pyridine rings = 72.56 (13°], affording a two-dimensional 44 sheet structure in the crystal.

Synthesis of schiff bases of pyridine-4-carbaldehyde and their antioxidant and DNA binding studies

International Nuclear Information System (INIS)

Shamim, S.; Murtaza, S.; Nazar, M.F.

2016-01-01

A series of Schiff bases of pyridine-4-carbaldehyde with 3-aminobenzoic acid, 2-aminobenzoic acid, 4-aminobenzoic acid, 1,3-phenylenediamine, 1,2-phenylenediamine, 2-aminothiophenol, 4-aminoantipyrene, 2-aminophenol and naphthalene-1-amine was synthesized and compounds were characterized by FTIR, NMR and mass spectrometry. The synthesized compounds were evaluated for their antioxidant and DNA binding interaction studies. DPPH scavenging method was used to evaluate the antioxidant activities of synthesized Schiff bases at six gradually increasing concentrations of 0.5-5mg/ml. 2-((pyridin-4-ylmethylidene)amino)phenol came out to be the most efficient antioxidant at a concentration of 4mg/ml with 74% inhibition of free radicals generated by DPPH. The DNA binding interaction of the synthesized Schiff bases was determined using UV-Vis absorption titration method. Both the hypochromic and hyperchromic effects were observed along the series. The values for the binding constant (K) and free energy change (G) were calculated and most of the Schiff bases have high positive K values which indicate the efficient binding of Schiff bases with DNA. Molecular docking studies as carried out using PatchDock molecular algorithm software also indicated the high values for geometrical shape complementarity score suggesting the stabilities of Schiff bases/DNA complex. Docking studies also suggested the minor groove binding of the Schiff bases with DNA. Drug-likeness of the synthesized compounds was also tested in silico and the results are accordingly discussed. (author)

Radiochemical synthesis of 3-(4-[18F] Fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c] pyridin-5-one: A putative dopamine D$4 receptor PET imaging agent

International Nuclear Information System (INIS)

Li, G.C.; Yin, D.Z.; Wang, M.W.; Cheng, D.F.; Wang, Y.X.

2005-01-01

Introduction: The dopamine D 4 receptor has lately received increasing interest since it has been hypothesized to be involved in the pathology and pharmacotherapy of schizophrenia. While this receptor is expressed in lower density in various extrastriatal brain regions and its distribution is still unclear due to the lack of suitable imaging agent and its level change in schizophrenia is controversial. Herein, based on the structure-activity analysis of chromeno[3, 4-c]pyridine- 5-ones as potential dopamine D 4 receptor ligands, a putative D 4 subtype positron emission tomography (PET) radioligand, 3-(4-[ 18 F]fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one ([ 18 F]FHTP), was designed and synthesized. Methods: The radiochemical synthesis route was shown in Figure 1. [ 18 F]Fluoride was produced with a Cyclone-30 (IBA, Belgium) by 18 O(p, n) 18 F reaction using enriched 18 O-H 2 O and eluted from a Dowex 1-X8 anion-exchange column with aqueous potassium carbonate (20 mg/mL). 4-[ 18 F]Fluorobenzaldehyde was prepared according to the method reported by Alan A. Wilson and et al.. Then, 8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one, sodium cyanoborohydride, methanol and acetic acid were added to the dry residue, The mixture was then sealed and heated at 120 degree C for 12 min. At the end of the reaction, the mixture was cooled, diluted with ethyl acetate and washed with water. The extracted organic layer was passed through a small anhydrous magnesium sulfate column. After removal of the solvents in the mixture at 50 degree C under a stream of nitrogen, the obtained residue was redissolved in methanol and purified with a semi-preparative HPLC system, then the desired product was collected. Results: The radiochemical synthesis of [ 18 F]FHTP took around 110 min at EOS with an overall radiochemical yield 19% (decay-corrected) and its radiochemical purity was higher than 95%. Conclusion: A presumed dopamine D 4 receptor PET

Poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers with Various Molecular Weights as Phase Change Materials

Directory of Open Access Journals (Sweden)

Dongfang Pei

2018-02-01

Full Text Available At present, research on the relationship of comb-like polymer phase change material structures and their heat storage performance is scarce. Therefore, this relationship from both micro and macro perspectives will be studied in this paper. In order to achieve a high phase change enthalpy, ethylene glycol segments were introduced between the vinyl and the alkyl side chains. A series of poly(mono/diethylene glycol n-tetradecyl ether vinyl ethers (PC14EnVEs (n = 1, 2 with various molecular weights were polymerized by living cationic polymerization. The results of PC14E1VE and PC14E2VE showed that the minimum number of carbon atoms required for side-chain crystallization were 7.7 and 7.2, which were lower than that reported in the literature. The phase change enthalpy 89 J/g (for poly(mono ethylene glycol n-tetradecyl ether vinyl ethers and 86 J/g (for poly(hexadecyl acrylate were approximately equal. With the increase of molecular weight, the melting temperature, the melting enthalpy, and the initial thermal decomposition temperature of PC14E1VE changed from 27.0 to 28.0 °C, from 95 to 89 J/g, and from 264 to 287 °C, respectively. When the number average molar mass of PC14EnVEs exceeded 20,000, the enthalpy values remained basically unchanged. The introduction of the ethylene glycol chain was conducive to the crystallization of alkyl side chains.

Cyanoacetanilides intermediates in heterocyclic synthesis. Part 6: Preparation of some hitherto unknown 2-oxopyridine, bipyridine, isoquinoline and chromeno[3,4-c]pyridine containing sulfonamide moiety

Directory of Open Access Journals (Sweden)

Yousry A. Ammar

2014-11-01

Full Text Available Treatment of cyanoacetanilide derivative 1 with tetracyanoethylene (2 in dioxane/triethylamine furnished 2-pyridone derivative 6. Aminopyridine 9 was obtained by cyclization of compound 1 with ketene dithioacetal 7/EtONa. Cyclocondensation of 1 with malononitrile and/or acetylacetone (1:1 M ratio gave pyridine derivatives 11 and 13. Ternary condensation of compound 1, aliphatic aldehydes and malononitrile (1:1:1 M ratio yielded the 2-pyridones 20a and b. Bipyridines 22a–c were prepared by refluxing of compound 21 with active methylene reagents. Cyclization of chromene derivatives 24 and 28 with malononitrile produced the novel chromeno[3,4-c]pyridine 26 and pyrano[3′,2′:6,7]chromeno[3,4-c]pyridine 29.

The Effect of Plasma Surface Treatment on a Porous Green Ceramic Film with Polymeric Binder Materials

International Nuclear Information System (INIS)

Yun Jeong Woo

2013-01-01

To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process. The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials. The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis. The experimental results revealed the need for parameter analysis, including gas material, process time, flow rate, and discharge power, and supported a mechanism consisting of competing ablation and deposition processes. The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film's permeability by suppressing deposition of the ablated species. The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

Energy Technology Data Exchange (ETDEWEB)

Manaa, C., E-mail: chadlia.el.manaa@gmail.com [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Lejeune, M. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Kouki, F. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); Durand-Drouhin, O. [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d' Amiens, 33 rue Saint Leu, 80039 Amiens CEDEX 2 (France); Bouchriha, H. [Laboratoire des Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia); and others

2014-06-02

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method.

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized cyclohexane thin films

International Nuclear Information System (INIS)

Manaa, C.; Lejeune, M.; Kouki, F.; Durand-Drouhin, O.; Bouchriha, H.

2014-01-01

We investigate in the present study the effects of the radio-frequency plasma power on the opto-electronical properties of the polymeric amorphous hydrogenated carbon thin films deposited at room temperature and different radio-frequency powers by plasma-enhanced chemical vapor deposition method using cyclohexane as precursor. A combination of U.V.–Visible and infrared transmission measurements is applied to characterize the bonding and electronic properties of these films. Some film properties namely surface roughness, contact angle, surface energy, and optical properties are found to be significantly influenced by the radio-frequency power. The changes in these properties are analyzed within the microstructural modifications occurring during growth. - Highlights: • Effects of the radio-frequency power on the optoelectronic properties of thin films • Elaboration of plasma polymerized thin films using cyclohexane as precursor gas • The use of U.V.–Visible-infrared transmission, and optical gap • Study of the surface topography of the films by using Atomic Force microscopy • The use of a capacitively coupled plasma enhanced chemical vapor deposition method

Irradiated polymeric films and its possible application for radiation dosimetry

International Nuclear Information System (INIS)

Elkady, A.A.M.A.

2002-01-01

The aim of the present thesis is the development of a new polymeric films, laboratory prepared by sample uncouthly methods through dying them with different types of dyes. First unit containing three forms were prepared by casting polymeric solution of poly (vinyl chloride). First film was prepared by dying poly ( vinyl chloride ) film with eosin dye. This flexible plastic film dosimeter is bleached when exposed to gamma ray photons at low doses (2-7 kGy) indicating their suitability for eventual application in food irradiation processing. Also, another polyvinyl chloride film contain a Ph indicating dye namely methyl red undergo bleaching in the rang of (20-120 kGy) indicating their suitability for eventual application in sterilization. The third film was a Ph indicating dye cresol red dyed polyvinyl chloride in the presence of CI- containing substance (E.g.Chloralhydrate). This film have the advantage of clear visual in color at high dose gamma radiation. This film was developed using the phenomenon of HCl generation from the CI- containing substance upon irradiation. The produced HCl in turn changes the color of the indicator contained in the polymer. The Dosimetric parameters e.g. dose response, effect of relative humidity and temperature during irradiation on response as well as pre-and post-irradiation stability of all above films are discussed. In second unit, the film was prepared by sandwiching the radiochromic film (nylon 66) containing (Hexa-hydroxyethyl pararosaniline) by two layers of polyvinyl chloride containing UV absorption material namely (2-hydroxy-4n-octoxy-benzophenone) to improve the stability of this famous film towards UV-radiation. Finally, a mixed dyes of ph indicating dyes bromophenol red and cresol red dying a poly vinyl alcohol in the presence of chloral hydrate were prepared. This film exhibit color changes from original color (bagel), yellow to red. The useful dose range of this is (5-50 kGy) indicate its suitability for eventual

Basic and engineering studies of radiation induced reactions in the liquid phase. Final technical report, June 1, 1970-May 31, 1974

International Nuclear Information System (INIS)

1978-06-01

Laboratory studies reported on are ionic polymerization under superdry conditions, emulsion polymerization, and vinyl chloride polymerization. Engineering studies include the effect of moisture level on radiation-induced solution polymerization, effect of dose rate on radiation-induced emulsion polymerization of styrene, the effect of soap exchange in styrene emulsion polymerization, pilot plant studies of radiation induced emulsion polymerization of vinyl chloride, pilot plant studies of radiation-induced emulsion copolymerization of vinyl chloride with vinyl acetate, pilot plant study of radiation-induced graft emulsion polymerization of styrene onto polyvinyl chloride and poly(vinyl chloride-vinyl acetate), and radiation-induced precipitation polymerization of vinyl chloride in a flow reactor

Analysis of the polymeric film and fine dust obtained in plasma of acetylene and acetylene-nitrogen

International Nuclear Information System (INIS)

Rojas, Andres F; Ortiz, Jairo A; Devia Alfonso

1998-01-01

The results are presented from the resistance analyses to the corrosion of the polymeric covering obtained in plasma of acetylene, on a substrata of aluminum alloy, with the techniques of metallographic analysis, infrared and electrochemical, as much for the fine dust as for the grown film on aluminum. Also, the results of the electrochemical test of polarization made to these films will be shown, which demonstrated an improvement of 2.6 and 4.6 times in the resistance to the corrosion when the material treaty is exposed NaCl 0.2 N and Na H2 PO4 01 M, respectively, in comparison with the substrata without recovering. For the movie obtained in acetylene /nitrogen plasma on steel 1016 the micrographs of the superficial structure of the material they will be shown before and after being treated, which were used to measure the thickness of the cover; also, it will be given to know the results of the tests of adhesion and qualitative analysis of resistance before diverse chemical agents (such as: Benzene, Toluene, H2SO4, HNO3, NaCl, CACO3 NaOH and KOH) and the resistance results are presented from the cover to them

Studies on radiation-induced graft polymerization

International Nuclear Information System (INIS)

Omichi, Hideki

1978-09-01

Radiation-induced graft polymerization is used extensively to improve physical properties of polymers, but few processes are now commercialized. The reason for this is partly inadequate basic research on the reaction and partly the difficulty in developing the grafting process with large radiation source. Firstly, new techniques are proposed of studying kinetics of the graft polymerization in heterogeneous system. Based on the grafting yield, the molecular weight of graft chains, and the amount of radicals given by ESR and activation analysis, kinetic parameters are obtained and the reaction mechanism of grafting process is discussed. Secondly, the development of grafting process of poly (vinyl chloride)-butadiene is described. By study of the reaction, process design, construction and operation of the pilot plant, and economic analysis of the process, this process with 60 Co gamma ray sources is shown to be industrially promising. (author)

Synthesis of a novel series of 4-arylpiperazinyl derivatives linked to a 2-(pyridin-3-yl)-1H-benzimidazole as new Delavirdine analogues

International Nuclear Information System (INIS)

Pessoa-Mahana, David; Nunez, Andres; Espinosa, Christian; Mella-Raipn, Jaime; Pessoa-Mahana, Hernan

2010-01-01

The synthesis of a series of substituted arylpiperazines linked to a 2-(pyridin-3-yl)-1H-benzo[d]imidazole scaffold through an alkylic linker is reported. The novel 1-(2-(4-arylpiperazin-1-yl)alkyl)-2-(pyridin-3-yl)-1H-benzimidazole derivatives are structurally related to the anti-HIV-1 drug Delavirdine and belong to the bis(heteroaryl)piperazines family (BHAPs), a well known HIV-1 reverse transcriptase inhibitors group. (author)

Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane

Science.gov (United States)

Tupinambá, Rogerio Amaral; Claro, Cristiane Aparecida de Assis; Pereira, Cristiane Aparecida; Nobrega, Celestino José Prudente; Claro, Ana Paula Rosifini Alves

2017-01-01

ABSTRACT Introduction: Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Methods: Hexamethyldisiloxane (HMDSO) polymer films were deposited on conventional (n = 10) and self-ligating (n = 10) stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM) analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region) and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI) and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Results: Significant statistical differences (p 0.05). Conclusion: Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film. PMID:28902253

Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane

Directory of Open Access Journals (Sweden)

Rogerio Amaral Tupinambá

Full Text Available ABSTRACT Introduction: Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Methods: Hexamethyldisiloxane (HMDSO polymer films were deposited on conventional (n = 10 and self-ligating (n = 10 stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Results: Significant statistical differences (p 0.05. Conclusion: Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film.

Poly(vinyl alcohol)/poly(acrylic acid)/TiO2/graphene oxide nanocomposite hydrogels for pH-sensitive photocatalytic degradation of organic pollutants

International Nuclear Information System (INIS)

Moon, Young-E; Jung, Gowun; Yun, Jumi; Kim, Hyung-Il

2013-01-01

Graphical abstract: The photocatalytic removal of pollutants was improved by the two-step mechanism based on the adsorption of pollutants by hydrogel and the effective decomposition by combination of TiO 2 and graphene oxide. -- Highlights: • pH sensitive PVA/PAAc hydrogels were prepared by radical polymerization and condensation reaction. • PVA/PAAc/TiO 2 /graphene oxide nanocomposite hydrogels were used for treatment of basic waste water. • Photocatalytic acitivity of TiO 2 was improved by incorporation of graphene oxide. • Photocatalytic decomposition by nanocomposite hydrogel was improved by increasing pH. -- Abstract: Poly(vinyl alcohol)/poly(acrylic acid)/TiO 2 /graphene oxide nanocomposite hydrogels were prepared using radical polymerization and condensation reaction for the photocatalytic treatment of waste water. Graphene oxide was used as an additive to improve the photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO 2 nanocomposite hydrogels. Both TiO 2 and graphene oxide were immobilized in poly(vinyl alcohol)/poly(acrylic acid) hydrogel matrix for an easier recovery after the waste water treatment. The photocatalytic activity of poly(vinyl alcohol)/poly(acrylic acid)/TiO 2 /graphene oxide nanocomposite hydrogels was evaluated on the base of the degradation of pollutants by using UV spectrometer. The improved removal of pollutants was due to the two-step mechanism based on the adsorption of pollutants by nanocomposite hydrogel and the effective decomposition of pollutants by TiO 2 and graphene oxide. The highest swelling of nanocomposite hydrogel was observed at pH 10 indicating that poly(vinyl alcohol)/poly(acrylic acid)/TiO 2 /graphene oxide nanocomposite hydrogels were suitable as a promising system for the treatment of basic waste water

Analysis of annealed thin polymer films prepared from dichloro(methyl)phenylsilane by plasma polymerization

Czech Academy of Sciences Publication Activity Database

Cech, V.; Horvath, P.; Trchová, M.; Zemek, Josef; Matějková, Jiřina

2001-01-01

Roč. 82, - (2001), s. 2106-2112 ISSN 0021-8995 R&D Projects: GA ČR GV106/98/K013; GA ČR GA104/00/0708 Institutional research plan: CEZ:AV0Z1010914 Keywords : plasma polymerization * thin films * thermogravimetric analysis ( TSA ) * FTIR * ESCA/XPS Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.992, year: 2001

Synthesis and thermal characterization of CdS nano crystals in previously formed template of maleic anhydride-octene 1-vinyl butyl terpolymer

International Nuclear Information System (INIS)

Akbarov, O.H; Mammadova, R.E; Malikov, E.Y.

2008-01-01

Full text: Nano crystals have dimensions in the range 10100 nm. Crystals in this size range possess unique properties, which enable scientists to manufacture materials and devices capable of performing unimaginable tasks. For that reason synthesis of this semiconductor nano crystals is expedient. Many useful methods have been used for preparing sulphide semiconductor nano crystals, such as colloidal chemistry method, sol-gel method, inverse micelle method, in situ synthesis and assemble on polymer template. The most significant method is in situ synthesis and assemble of sulphide semiconductor nano crystals on polymer. Compared with other methods, the stability of nanoparticles is improved by the protection and confinement of the copolymer. Because of confinement and protection effects of template environmental risk is prevented in this method. On the base of this principles in situ synthesis of CdS nano crystals in maleic anhydride-octene 1-vinyl butyl terpolymer was realized in this scientific work. First of all in specific condition maleic anhydride, octene 1, and vinyl butyl ether were polymerized to form a terpolymer as the result of radical ter polymerization. In second step CdS nano crystals were synthesized in N,N-dimethylformamide solution of maleic anhydride-octene 1-vinyl butyl terpolymer through the reaction of thiourea with cadmium chloride. In this process CdCI 2 x 2.5H 2 O was dissolved in N,N-dimethylformamide solution of previously formed terpolymer and was heated in 90 0 C temperature for 4 hours with vigorous stirring. Then desired amount of thiourea in N,N-dimethylformamide was quickly injected into the reaction flask using a syringe. The reaction continued for another 1 hour, and a yellow clear solution was obtained, which indicated the formation of CdS nano crystals

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

International Nuclear Information System (INIS)

Biederman, H.; Holland, L.

1983-01-01

Fluorocarbon films have been prepared by plasma polymerization of CF 4 using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an r.f. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF 4 [25%]-argon[75%] mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF 4 [87%]-argon[13%] were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF 4 as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined. (orig.)

Metal doped fluorocarbon polymer films prepared by plasma polymerization using an RF planar magnetron target

Energy Technology Data Exchange (ETDEWEB)

Biederman, H.; Holland, L. (Sussex Univ., Brighton (UK). Lab. for Plasma Materials Processing)

1983-07-01

Fluorocarbon films have been prepared by plasma polymerization of CF/sub 4/ using an RF planar magnetron with an aluminium target. More than one order of magnitude higher deposition rate has been achieved in comparison with an R.F. diode system operated under similar conditions of monomer pressure and flow rate and power input. A glow discharge in a CF/sub 4/(25%)-argon(75%) mixture was used to incorporate aluminium from a target electrode into the polymer films. The foregoing mixture and another based on CF/sub 4/(87%)-argon(13%) were used in the RF discharge with a copper target. Some experiments with a gold target and pure CF/sub 4/ as the inlet gas were also made. The film structure was examined by SEM and TEM and characteristic micrographs are presented here. The composition of the films was estimated from an EAS study. The sheet resistivity of the metal/polymer film complexes was determined.

Preparation of novel pyrrolo [2,3-b]pyridine derivatives via a new concise synthetic approach

Energy Technology Data Exchange (ETDEWEB)

Guo, Na; Jia, Haiyong; You, Xing; Jiang, Du; Lu, Kui; Yu, Peng [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, Tianjin University of Science and Technology, Tianjin (China)

2015-04-15

The pyrrolo[2,3-b]pyridine core structure, a bioisostere of quinolones, is found in several molecules that possess important biological activity. We describe here a new, concise, three-step synthesis of pyrrolo[2,3-b]pyridines starting from L-alanine. A series of 4,7-dihydro-4-oxo-1H-pyrrolo[2,3-b]pyridine-5-carboxylic acid derivatives, which have not been previously reported, were synthesized using this approach.

Aquabis(4-methylbenzoato-κO;κ2O,O′-bis(pyridine-κNnickel(II

Directory of Open Access Journals (Sweden)

Li-Li Ji

2008-04-01

Full Text Available In the title mononuclear complex, [Ni(C8H7O22(C5H5N2(H2O], the NiII atom is in a distorted octahedral arrangement, coordinated by three carboxylate O atoms from one bidentate 4-methylbenzoate ligand and one monodentate 4-methylbenzoate ligand, two N atoms from pyridine ligands, axially positioned, and a water molecule. The equatorially positioned water molecule and uncoordinated carboxylate O atom form an intramolecular hydrogen bond. An intermolecular O—H...O hydrogen bond between the coordinated water molecule and carboxylate O atom of the 4-methylbenzoate ligand forms infinite chains along the b axis. These chains are connected by C—H...π interactions.

Hexaaquanickel(II tetraaquabis(μ-pyridine-2,6-dicarboxylatobis(pyridine-2,6-dicarboxylatotrinickelate(II octahydrate

Directory of Open Access Journals (Sweden)

Javad Safaei-Ghomi

2010-08-01

Full Text Available The title compound, [Ni(H2O6][Ni3(C7H3NO44(H2O4]·8H2O, was obtained by the reaction of nickel(II nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2 and 1,10-phenanothroline (phen in an aqueous solution. The latter ligand is not involved in formation of the title complex. There are three different NiII atoms in the asymmetric unit, two of which are located on inversion centers, and thus the [Ni(H2O6]2+ cation and the trinuclear {[Ni(pydc2]2-μ-Ni(H2O4}2− anion are centrosymmetric. All NiII atoms exhibit an octahedral coordination geometry. Various interactions, including numerous O—H...O and C—H...O hydrogen bonds and C—O...π stacking of the pyridine and carboxylate groups [3.570 (1, 3.758 (1 and 3.609 (1 Å], are observed in the crystal structure.

27 CFR 21.122 - Pyridine bases.

Science.gov (United States)

2010-04-01

....122 Pyridine bases. (a) Alkalinity. One ml of pyridine bases dissolved in 10 ml of water is titrated... condenser having a water jacket not less than 400 mm in length. A standardized thermometer is placed in the.... Dissolve 1 ml of pyridine bases in 100 ml of water. (1) Ten ml of this solution are treated with 5 ml of 5...

Mutagenicity of vinyl chloride after metabolic activation

Energy Technology Data Exchange (ETDEWEB)

Rannug, U; Johansson, A; Ramel, C; Wachtmeister, C A

1974-01-01

Vinyl chloride has recently been shown to cause a malignant liver tumor disease in man after occupational exposure in PVC plants. This actualizes the problem of whether such hazards could be avoided or at least diminished in the future by a screening for mutagenicity of chemicals used in industries. The basis for such a screening procedure is the close correlation between carcinogenic and mutagenic effects of chemicals. Experiments with Salmonella bacteria showed that the carcinogenic hazard of vinyl chloride could have been traced by means of mutagenicity tests. The data indicate that vinyl chloride is not mutagenic per se but becomes mutagenic after a metabolic activation in the liver. 24 references, 1 figure, 4 tables.

Preparation of germanium doped plasma polymerized coatings as ICF target ablators

International Nuclear Information System (INIS)

Brusasco, R.M.; Saculla, M.D.; Cook, R.C.

1994-01-01

Targets for Inertial Confinement Fusion (ICF) experiments at the Lawrence Livermore National Laboratory (LLNL) utilize an organic (CH) ablator coating prepared by plasma polymerization. Some of these experiments require a mid-Z dopant in the ablator coating to modify the opacity of the shell. Bromine had been used in the past, but the surface finish of brominated CH degrades rapidly with time upon exposure to air. This paper describes the preparation and characterization of plasma polymer layers containing germanium as a dopant at concentrations of between 1.25 and 2.25 atom percent. The coatings are stable in air and have an rms surface roughness of 7--9 nm (modes 10--1,000) which is similar to that obtained with undoped coatings. High levels of dopant result in cracking of the inner mandrel during target assembly. Possible explanations for the observed cracking behavior will be discussed

Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

International Nuclear Information System (INIS)

Xi Peng; Gu Xiaohua; Cheng Bowen; Wang Yufei

2009-01-01

Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, 1 H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

Polyanionic pH-responsive polystyrene-b-poly(4-vinyl pyridine-N-oxide) isoporous membranes

KAUST Repository

Shevate, Rahul

2015-12-01

Recently isoporous block copolymer (BCP) membranes obtained by non-solvent induced phase separation gained a lot of attention due to their highly ordered surface layer, high flux and superior separation properties. These polystyrene-b-poly-4-vinylpyridine (PS-b-P4VP) based membranes showed a strong flux dependence of pH; pores closed at low pH and opened at high pH. The pH-response could now be reversed by a simple post modification; pores are now opening at low pH and closing at high pH. The original membrane was transformed into a polyanionic pH responsive membrane in a one step chemical modification without affecting the isoporous surface morphology. A polystyrene-b-poly-4-vinylpyridine-N-oxide (PS-b-P4VPN-oxide) membrane is obtained by selective oxidation of the PS-b-P4VP membrane. The in situ generated peracid obtained by reacting acetic acid and hydrogen peroxide is employed for oxidation. Surprisingly not only the asymmetric membrane structure with the isoporous skin was retained, but also the mechanical and chemical membrane stability was improved significantly. The modified membranes are insoluble in solvents like DMF, NMP and DMSO. Two kinds of PS-b-P4VP based isoporous membranes are available now with reverse flux response to pH. This opens the door to new interesting charge based fractionations.

Acid-base strengths in pyridine

NARCIS (Netherlands)

Bos, M.; Dahmen, E.A.M.F.

1971-01-01

Although pyridine is a solvent with a low dielectric constant, spectrophotometric determinations show simple dissociation without ion pairs as intermediates for some sulfonphthaleins and polynitrophenols in pyridine. The salts of a number of amines and hydrochloric acid, perchloric acid and picric

The study of polymeric hydro-gels with unique properties obtained by polymerization with gamma radiation processing

International Nuclear Information System (INIS)

Dragusin, M.

1995-01-01

This thesis presents the work carried out on polymeric hydro-gels obtained by radiation processing using 60 Co gamma rays from the irradiation facility IETI-10.000 (10 k Ci), and on the polymeric hydro-gels obtained by irradiation with the electron beams from a linear accelerator (6 MeV). The aim of the study was to determine the effect of the rate dose and total dose absorbed in the materials. There are presented the preparation methods of homo- and co-polymer hydro-gels (acrylics, namely anionic and neutral monomers (acrylamide, acrylic acid, vinyl acetate) and cationic monomers (di-methyl di-allyl ammonium chloride)) such as floculants, additives, absorbers, etc. Concerning with these we have analysed the preparation methods, the mechanical, thermal, diffusivity, and swelling properties of polymeric hydro-gels in a large variety of gels of type I or II. The technological aspects and end use were studied in connection with the characteristics of the radiation processing of these hydro-gels as a function of chemical composition rate and absorbed dose, swelling degree (low and very high hydro-soluble), mechanical and diffusional properties. (author) 33 figs., 12 tabs., 101 refs

Effects of O2 and H2O plasma immersion ion implantation on surface chemical composition and surface energy of poly vinyl chloride

International Nuclear Information System (INIS)

Zhang Wei; Chu, Paul K.; Ji Junhui; Zhang, Yihe; Jiang Zhimin

2006-01-01

Oxygen and water plasma immersion ion implantation (PIII) was used to modify poly vinyl chloride (PVC) to enhance oxygen-containing surface functional groups for more effective grafting. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and contact angle measurements. Our experimental results show that both oxygen and water PIII can greatly improve the O to C ratios on the surface. The optimal plasma processing conditions differ for the two treatments. The hydrophilicity and surface energy of the plasma-implanted PVC are also improved significantly. Our results indicate that O 2 and H 2 O PIII increase both the polar and dispersion interactions and consequently the surface energy. It can be explained by the large amount of oxygen introduced to the surface and that many C-C bonds are transformed into more polar oxygen containing functional groups

Synthesis, Structures and Properties of Cobalt Thiocyanate Coordination Compounds with 4-(hydroxymethyl)pyridine as Co-ligand

OpenAIRE

Stefan Suckert; Luzia S. Germann; Robert E. Dinnebier; Julia Werner; Christian Näther

2016-01-01

Reaction of Co(NCS)2 with 4-(hydroxymethyl)pyridine (hmpy) leads to the formation of six new coordination compounds with the composition [Co(NCS)2(hmpy))4] (1), [Co(NCS)2(hmpy)4] × H2O (1-H2O), [Co(NCS)2(hmpy)2(EtOH)2] (2), [Co(NCS)2(hmpy)2(H2O)2] (3), [Co(NCS)2(hmpy)2]n∙4 H2O (4) and [Co(NCS)2(hmpy)2]n (5). They were characterized by single crystal and powder X-ray diffraction experiments, thermal and elemental analysis, IR and magnetic measurements. Compound 1 and 1-H2O form discrete comple...

Preparation of Thermoplastic Poly (vinyl Alcohol), Ethylene Vinyl Acetate and Vinyl Acetate Versatic Ester Blends for Exterior Masonry Coating

International Nuclear Information System (INIS)

EL-Nahas, H.H.; Gad, Y.H.; Magida, M.M.

2013-01-01

Blend systems including ethylene vinyl acetate (EVA), poly (vinyl alcohol) (PVA) and vinyl acetate versatic copolymer latex (VAcVe) were prepared and used as exterior coatings. Mechanical and thermal properties of the blends were investigated using a testo meter, shore hardness tester, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The water resistance of the samples was measured. Effect of ionizing irradiation on gel content, tensile strength and surface hardness were also followed. The blend offers binder base for exterior masonry coating systems having superior water resistant and mechanical properties

Copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines: synthesis of imidazopyridine derivatives.

Science.gov (United States)

Yu, Jipan; Jin, Yunhe; Zhang, Hao; Yang, Xiaobo; Fu, Hua

2013-12-02

A novel, efficient, and practical method for the synthesis of imidazopyridine derivatives has been developed through the copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines with N-(alkylidene)-4H-1,2,4-triazol-4-amines. The procedure occurs by cleavage of the N-N bond in the N-(alkylidene)-4H-1,2,4-triazol-4-amines and activation of an aryl C-H bond in the substituted pyridines. This is the first example of the preparation of imidazopyridine derivatives by using pyridines as the substrates by transition-metal-catalyzed C-H functionalization. This method should provide a novel and efficient strategy for the synthesis of other nitrogen heterocycles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of radiation-induced polymerization of vinyl monomers adsorbed on inorganic substances. VIII. Polymerization of styrene and methyl methacrylate adsorbed on aerosil

International Nuclear Information System (INIS)

Fukano, K.; Kageyama, E.

1976-01-01

Aerosol is silica having a purity which is very high compared with that of silica gel and having, unlike silica gel, no micropores. To investigate the effects of impurities and micropores on the radiation-induced polymerization of styrene and methyl methacrylate adsorbed on silica gel, the radiation-induced polymerization of styrene and methyl methacrylate adsorbed on Aerosil was carried out. The results of both the styrene--Aerosil 300 system and the methyl methacrylate--Aerosil 300 system were similar to those of the styrene-silica gel and methyl methacrylate-silica gel systems, respectively. This suggests that in the radiation-induced polymerization of both styrene--silica gel and methyl methacrylate--silica gel systems the impurities and the presence of micropores have almost no effect on the reaction mechanism. The effect of aluminum as an impurity was investigated on the styrene--Aerosil MOX 170 system. It was found that aluminum accelerated the cationic polymerization

N-[5-Methyl-2-(2-nitro-phen-yl)-4-oxo-1,3-thia-zolidin-3-yl]pyridine-3-carboxamide monohydrate.

Science.gov (United States)

Akkurt, Mehmet; Celik, Ismail; Demir, Hale; Ozkırımlı, Sumru; Büyükgüngör, Orhan

2011-01-08

In the title compound, C(16)H(14)N(4)O(4)S·H(2)O, the benzene and pyridine rings make a dihedral angle of 85.8 (1)°. Both enanti-omers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C(5) of the thia-zolidine ring) were therefore refined with common site-occupation factors of 0.531 (9) and 0.469 (9), respectively, for each stereoisomer. In the crystal, inter-molecular N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds link the mol-ecules, forming a three-dimensional supra-molecular network. The crystal structure further shows π-π stacking inter-actions [centroid-centroid distance = 3.5063 (13) Å] between the pyridine rings.

Two-dimensional structure of poly[[[μ2-1,4-bis(pyridin-4-ylbutane]bis(μ4-pentanedioatodicopper(II] acetonitrile disolvate

Directory of Open Access Journals (Sweden)

Do Nam Lee

2017-10-01

Full Text Available In the title compound, {[Cu2(μ4-C5H6O42(μ2-C14H16N2]·2CH3CN}n, the Cu2 dinuclear units are connected by glutartate ligands, forming one-dimensional double chains. These chains, are in turn bridged by 1,4-bis(pyridin-4-ylbutane ligands to form a two-dimensional layer structure parallel to (112. The carboxylate groups of the glutarate ligand bridge two copper(II ions, forming a paddle-wheel-type Cu2(CO24 dinuclear secondary building unit. A crystallographic inversion centre is located midway between two CuII ions, with a Cu...Cu distance of 2.639 (3 Å. The coordination geometry of the unique CuII ion is slightly disorted square pyramidal, formed by four equatorial carboxylate O atoms and an axial pyridyl N atom.

21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

Science.gov (United States)

2010-04-01

... in powder form having a particle size such that 100 percent will pass through a U.S. Standard Sieve No. 40 and such that not more than 10 percent will pass through a U.S. Standard Sieve No. 200. (1... analysis. (e) Other specifications and limitations. The vinyl chloride-lauryl vinyl ether copolymers...

Simultaneous LC-MS/MS determination of five tripterygium pyridine alkaloids in dog plasma and its application to their pharmacokinetic study after oral administration of tripterygium glycosides tablets.

Science.gov (United States)

Su, Meng-xiang; Song, Min; Yang, Da-song; Shi, Jin-fang; Di, Bin; Hang, Tai-jun

2015-05-15

A sensitive and selective liquid chromatography tandem mass spectrometric method was developed and validated for the simultaneous determination of five pyridine alkaloids contained in tripterygium glycosides tablets (triptolide, wilforine, wilforgine, wilfording and wilfortrine) in dog plasma. The analysis was carried out on a Sepax GP-Phenyl column using a mixture of methanol and 10mmol/L ammonium formate buffer solution containing 0.1% formic acid (75:25, v/v) as the mobile phase pumped at a flow-rate of 1.0mL/min. All MS data were obtained in the positive ESI mode with selective multiple reaction monitoring of ion transitions. The method was fully validated to be accurate and precise with a linear range of 0.2-1000ng/mL for triptolide and 0.05-1000ng/mL for the other four pyridine alkaloids. The intra-day and inter-day precisions (relative standard deviation, RSD, %) were within 10.6% and 14.0%, respectively, and the relative error (RE, %) were all less than 13.1%. The method was successfully applied to multi-components pharmacokinetic study of the five pyridine alkaloids in beagle dogs after a single oral administration of 3mg/kg and 30mg/kg tripterygium glycosides tablets, respectively, and a multiple oral administration of 30mg/kg for 6 consecutive days. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of gamma radiation on the poly(vinyl alcohol)

International Nuclear Information System (INIS)

Terence, M.C.; Guedes, S.M.L.

2000-01-01

The poly(vinyl alcohol) (PVAL) is a polymer used as bio material. The PVAL was used as ocular insert and may be used as a drug delivery system (DDS) for pair PVAL/gancyclovir, where the last one is used for treatment of people with retinitis caused by cytomegalovirus. These inserts are crosslinked systems. The crosslink was induced by gamma radiation applied in polymer. The samples of PVAL was irradiated by gamma rays with doses in the range 0 to 100 kGy. On irradiated PVAL samples was observed a low yellowness, attributed to the formation of polymeric radicals that are stable in the structure of the polymer, from radiolysis of PVAL. (author)

A Visible Light Initiating System for Free Radical Promoted Cationic Polymerization

Science.gov (United States)

1994-02-02

identify the end groups in the polymer of cyclohexene oxide. N,N-Dimethylnaphthyl amine (DNA), a compound with high fluorescence quantum yield, was used...candidates to be polymerized via a cationic mechanism include cyclic ethers, cyclic formals and acetals, vinyl ethers, and epoxy compounds . Of these...reported sensitizer, bears two dimethylamino groups, is direct evidence that an aromatic amine can be present in a cationically photopolymerizable system

Candida Rugosa Lipase-catalyzed Kinetic Resolution of 3-(Isobutyryloxy)methyl 4-[2-(Difluoromethoxy)phenyl]-2-methyl-5,5-dioxo-1,4-dihydrobenzothieno[3,2-b]pyridine-3-carboxylate

NARCIS (Netherlands)

Sobolev, A.; Zhalubovskis, R.; Franssen, M.C.R.; Vigante, B.; Chekavichus, B.; Duburs, G.; Groot, de Æ.

2004-01-01

The lipase-catalyzed kinetic resolution of 3-(isobutyryloxy)methyl 4-[2-(difluoromethoxy)phenyl]-2-methyl-5,5-dioxo-1,4-dihydrobenzothieno[3,2-b]pyridine-3-carboxylate has been performed. The most enantioselective reaction (E = 28) was transesterification with n-butanol in water-saturated toluene at

Studies on surface graft polymerization of acrylic acid onto PTFE film by remote argon plasma initiation

International Nuclear Information System (INIS)

Wang Chen; Chen Jierong

2007-01-01

The graft polymerization of acrylic acid (AAc) was carried out onto poly(tetrafluoroethylene) (PTFE) films that had been pretreated with remote argon plasma and subsequently exposed to oxygen to create peroxides. Peroxides are known to be the species responsible for initiating the graft polymerization when PTFE reacts with AAc. We chose different parameters of remote plasma treatment to get the optimum condition for introducing maximum peroxides (2.87 x 10 -11 mol/cm 2 ) on the surface. The influence of grafted reaction conditions on the grafting degree was investigated. The maximum grafting degree was 25.2 μg/cm 2 . The surface microstructures and compositions of the AAc grafted PTFE film were characterized with the water contact angle meter, Fourier-transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Contact angle measurements revealed that the water contact angle decreased from 108 o to 41 o and the surface free energy increased from 22.1 x 10 -5 to 62.1 x 10 -5 N cm -1 by the grafting of the AAc chains. The hydrophilicity of the PTFE film surface was greatly enhanced. The time-dependent activity of the grafted surface was better than that of the plasma treated film

Bacterial adhesion on conventional and self-ligating metallic brackets after surface treatment with plasma-polymerized hexamethyldisiloxane.

Science.gov (United States)

Tupinambá, Rogerio Amaral; Claro, Cristiane Aparecida de Assis; Pereira, Cristiane Aparecida; Nobrega, Celestino José Prudente; Claro, Ana Paula Rosifini Alves

2017-01-01

Plasma-polymerized film deposition was created to modify metallic orthodontic brackets surface properties in order to inhibit bacterial adhesion. Hexamethyldisiloxane (HMDSO) polymer films were deposited on conventional (n = 10) and self-ligating (n = 10) stainless steel orthodontic brackets using the Plasma-Enhanced Chemical Vapor Deposition (PECVD) radio frequency technique. The samples were divided into two groups according to the kind of bracket and two subgroups after surface treatment. Scanning Electron Microscopy (SEM) analysis was performed to assess the presence of bacterial adhesion over samples surfaces (slot and wings region) and film layer integrity. Surface roughness was assessed by Confocal Interferometry (CI) and surface wettability, by goniometry. For bacterial adhesion analysis, samples were exposed for 72 hours to a Streptococcus mutans solution for biofilm formation. The values obtained for surface roughness were analyzed using the Mann-Whitney test while biofilm adhesion were assessed by Kruskal-Wallis and SNK test. Significant statistical differences (pbrackets after surface treatment and between conventional and self-ligating brackets; no significant statistical differences were observed between self-ligating groups (p> 0.05). Plasma-polymerized film deposition was only effective on reducing surface roughness and bacterial adhesion in conventional brackets. It was also noted that conventional brackets showed lower biofilm adhesion than self-ligating brackets despite the absence of film.

Ionic polymerization of p-methoxystyrene and other styrene derivatives by radiation. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Hayashi, K; Pepper, D C [Trinity Coll., Dublin (Ireland)

1976-01-01

Polymerization of p-methoxystyrene by radiation was studied in bulk. Upon drying the monomer, the rate of polymerization, Rsub(p), became greater, changing its dose rate dependence from 0.5 to 1. The molecular weight distribution of the obtained polymers failed to give a bimodal curve; however, the peak molecular weight increased with higher Rsub(p). These kinetic features can be explained by a coexistence of radical and cationic mechanisms, as has been established in styrene, though there remain ambiguities about the effects of additives. Copolymerizations with styrene and 2-chloroethyl vinyl ether also showed a cationic nature for the reaction. A survey of possibilities of ionic polymerization by radiation was also carried out in ten ring-substituted styrene derivatives.

(E-4-Methoxy-3,5-dimethyl-2-[(3-nitrophenylethenyl]pyridine

Directory of Open Access Journals (Sweden)

Youness El Bakri

2016-12-01

Full Text Available In the crystal of the title compound, C16H16N2O3, weak C—H...O hydrogen bonds involving the nitro group as acceptor form chains extending in the b-axis direction. The chains are arranged into layers by π–π stacking interactions along the c-axis direction between the substituted pyridine rings, separated by 3.624 (1 Å.

Crystal structures of 2-benzylamino-4-(4-bromophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile and 2-benzylamino-4-(4-chlorophenyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carbonitrile

Directory of Open Access Journals (Sweden)

R. A. Nagalakshmi

2015-01-01

Full Text Available In the title compounds, C24H22BrN3, (I, and C24H22ClN3, (II, the 2-aminopyridine ring is fused with a cycloheptane ring, which adopts a half-chair conformation. The planes of the phenyl and benzene rings are inclined to that of the central pyridine ring [r.m.s. deviations = 0.0083 (1 and 0.0093 (1 Å for (I and (II, respectively] by 62.47 (17 and 72.51 (14°, respectively, in (I, and by 71.44 (9 and 54.90 (8°, respectively, in (II. The planes of the aromatic rings are inclined to one another by 53.82 (17° in (I and by 58.04 (9° in (II. In the crystals of both (I and (II, pairs of N—H...Nnitrile hydrogen bonds link the molecules, forming inversion dimers with R22(12 ring motifs. In (I, the resulting dimers are connected through C—H...Br hydrogen bonds, forming sheets parallel to (10-1, and π–π interactions [inter-centroid distance = 3.7821 (16 Å] involving inversion-related pyridine rings, forming a three-dimensional network. In (II, the resulting dimers are connected through π–π interactions [inter-centroid distance = 3.771 (2 Å] involving inversion-related pyridine rings, forming a two-dimensional network lying parallel to (001.

Plasma-initiated polymerization of chitosan-based CS-g-P(AM-DMDAAC) flocculant for the enhanced flocculation of low-algal-turbidity water.

Science.gov (United States)

Sun, Yongjun; Zhu, Chengyu; Sun, Wenquan; Xu, Yanhua; Xiao, Xuefeng; Zheng, Huaili; Wu, Huifang; Liu, Cuiyun

2017-05-15

In this work, a highly efficient and environmentally friendly chitosan-based graft flocculant, namely, acrylamide- and dimethyl diallyl ammonium chloride-grafted chitosan [CS-g-P(AM-DMDAAC)], was prepared successfully through plasma initiation. FTIR results confirmed the successful polymerization of CS-g-P(AM-DMDAAC) and P(AM-DMDAAC). P(AM-DMDAAC) was the copolymer of acrylamide- and dimethyl diallyl ammonium chloride. SEM results revealed that a densely cross-linked network structure formed on the surface. XRD results verified that the ordered crystal structure of chitosan in CS-g-P(AM-DMDAAC) was changed into an amorphous structure after plasma-induced polymerization. The flocculation results of low-algal-turbidity water further showed the optimal flocculation efficiency of turbidity removal rate, COD removal rate, and Chl-a removal rate were 99.02%, 96.11%, and 92.20%, respectively. The flocculation efficiency of CS-g-P(AM-DMDAAC) were significantly higher than those obtained by cationic polyacrylamide (CPAM) and Polymeric aluminum and iron (PAFC). This work provided a valuable basis for the design of eco-friendly naturally modified polymeric flocculants to enhance the flocculation of low-algal-turbidity water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Plasma Polymerized Thin Films of Maleic Anhydride and 1,2-methylenedioxybenzene for Improving Adhesion to Carbon Surfaces

DEFF Research Database (Denmark)

Drews, Joanna Maria; Goutianos, Stergios; Kingshott, Peter

2007-01-01

Low power 2-phase AC plasma polymerization has been used to surface modify glassy carbon substrates that are used as an experimental model for carbon fibers in reinforced composites. In order to probe the role of carboxylic acid density on the interfacial adhesion strength a combination...

The synthesis, characterization and optical properties of novel 1,3,4-oxadiazole-containing imidazo[1,5-a]pyridine derivatives

International Nuclear Information System (INIS)

Ge Yanqing; Hao Benqian; Duan Guiyun; Wang Jianwu

2011-01-01

A series of novel substituted 1,3,4-oxadiazole derivatives were synthesized by the reaction of 3-butyl-1-chloroimidazo[1,5-a]pyridine-7-carbohydrazide with propionyl chloride and substituted benzoic chloride in the presence of phosphorus oxychloride. The compounds were characterized using IR, 1 H NMR, 13 C NMR and HRMS. Absorption and fluorescence spectra were measured in dichloromethane; an intense absorption maxima was noted at ca. 290 nm and emission maxima was noted at ca. 470 nm. The absorption spectra of the 1,3,4-oxadiazole derivatives reveal that a phenyl and an ethyl group attached to the 1,3,4-oxadiazole ring markedly influenced the maximum absorption. The structures based on density function theory (DFT) calculation show planar configurations for the compounds. The calculated molecular orbital correlates well with their absorption. - Research highlights: → Novel imidazo[1,5-a]pyridine derivatives were synthesized. → The structures were determined by IR, 1 H NMR, 13 C NMR and HRMS spectra. → We investigated the absorption and fluorescence spectral characteristics of the compounds. → The side group in 1,3,4-oxadiazole ring can affect its photophysical properties markedly. → Quantum calculation correlates well with their absorption.

Bis[O,O′-bis(4-tert-butylphenyl dithiophosphato-κ2S,S′]bis(pyridine-κNlead(II

Directory of Open Access Journals (Sweden)

Xiulan Zhang

2013-09-01

Full Text Available In the title compound, [Pb(C20H26O2PS22(C5H5N2], the PbII ion is coordinated by two S,S′-bidentate anions and two pyridine molecules. The PbN2S4 coordination geometry approximates to a pentagonal bipyramid with one equatorial site vacant. The N atoms occupy the axial sites. One of the pyridine molecules is disordered over two sets of sites in a 0.907 (7:0.093 (7 ratio and one of the tert-butyl groups is disordered over two sets of sites in a 0.534 (6:0.466 (6 ratio. An intramolecular C—H...O interaction occurs in one of the ligands. In the crystal, pairs of short Pb...S contacts [3.4018 (11 Å] generate a centrosymmetric dimeric assembly with the distant S atom lying in the region of the vacant coordination site of the metal atom. No directional packing interactions occur.

About a possibility of increasing the adhesion strength between mineral glass and polymeric binder under radio-frequency induction plasma treatment

International Nuclear Information System (INIS)

Miftakhov, I S; Trofimov, A V; Nagmutdinova, A I; Voznesensky, E F; Sharifullin, F S; Krasina, I V; Rakhmatullina, G R

2017-01-01

The paper investigated influences of radio-frequency induction plasma treatment on the surface of sheet mineral glasses for household purpose. Discussion for casting the most suitable treatment modes and theirs substantiation is shown. During the investigation the most productive plasma treatment modes for applied binders have been found. It is shown that the durability of adhesive joints between mineral glass and polymeric binder under low-temperature plasma treatment increase to 65%. (paper)

Miscibility and Hydrogen Bonding in Blends of Poly(4-vinylphenol/Poly(vinyl methyl ketone

Directory of Open Access Journals (Sweden)

Hana Bourara

2014-10-01

Full Text Available The miscibility and phase behavior of poly(4-vinylphenol (PVPh with poly(vinyl methyl ketone (PVMK was investigated by differential scanning calorimetry (DSC, Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. It was shown that all blends of PVPh/PVMK are totally miscible. A DSC study showed the apparition of a single glass transition (Tg over their entire composition range. When the amount of PVPh exceeds 50% in blends, the obtained Tgs are found to be significantly higher than those observed for each individual component of the mixture, indicating that these blends are capable of forming interpolymer complexes. FTIR analysis revealed the existence of preferential specific interactions via hydrogen bonding between the hydroxyl and carbonyl groups, which intensified when the amount of PVPh was increased in blends. Furthermore, the quantitative FTIR study carried out for PVPh/PVMK blends was also performed for the vinylphenol (VPh and vinyl methyl ketone (VMK functional groups. These results were also established by scanning electron microscopy study (SEM.

Crystal structure and DFT study of (E-4-[({4-[(pyridin-2-ylmethylideneamino]phenyl}aminomethyl]phenol

Directory of Open Access Journals (Sweden)

Md. Serajul Haque Faizi

2018-03-01

Full Text Available In the title Schiff base compound, C19H17N3O, the configuration about the C=N bond is E. The molecule is non-planar, with the phenolic and pyridine rings being inclined to the central benzene ring by 56.59 (4 and 15.13 (14°, respectively. In the crystal, molecules are linked by pairs of O—H...N hydrogen bonds, forming inversion dimers. The dimers are connected to neighbouring dimers by N—H...O hydrogen bonds and C—H...π interactions, forming layers parallel to the bc plane. The layers are linked by offset π–π interactions [intercentroid distance = 3.779 (2 Å], forming a three-dimensional supramolecular structure. Quantum chemical calculations of the molecule are in good agreement with the solid-state structure.

Crystal structure of bis(azido-κNbis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]cobalt(II

Directory of Open Access Journals (Sweden)

Abdelhakim Laachir

2015-05-01

Full Text Available In the mononuclear title complex, [Co(N32(C12H8N4S2], the cobalt(II atom is located on an inversion centre and displays an axially weakly compressed octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole ligands, whereas the axial positions are occupied by N atoms of the azide anions. The thiadiazole and pyridine rings linked to the metal are almost coplanar, with a maximum deviation from the mean plane of 0.0273 (16 Å. The cohesion of the crystal is ensured by weak C—H...N hydrogen bonds and by π–π interactions between pyridine rings [intercentroid distance = 3.6356 (11 Å], forming a layered arrangement parallel to (001. The structure of the title compound is isotypic with that of the analogous nickel(II complex [Laachir et al. (2013. Acta Cryst. E69, m351–m352].

Crystal structure of bis(azido-κNbis[2,5-bis(pyridin-2-yl-1,3,4-thiadiazole-κ2N2,N3]nickel(II

Directory of Open Access Journals (Sweden)

Abdelhakim Laachir

2015-02-01

Full Text Available Reaction of 2,5-bis(pyridin-2-yl-1,3,4-thiadiazole and sodium azide with nickel(II triflate yielded the mononuclear title complex, [Ni(N32(C12H8N4S2]. The NiII ion is located on a centre of symmetry and is octahedrally coordinated by four N atoms of the two bidentate heterocyclic ligands in the equatorial plane. The axial positions are occupied by the N atoms of two almost linear azide ions [N—N—N = 178.8 (2°]. The thiadiazole and pyridine rings of the heterocyclic ligand are almost coplanar, with a maximum deviation from the mean plane of 0.0802 (9 Å. The cohesion of the crystal structure is ensured by π–π interactions between parallel pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.6413 (14 Å], leading to a layered arrangement of the molecules parallel to (001.

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH4)2(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

International Nuclear Information System (INIS)

Zeynizadeh, Behzad; Faraji, Fariba

2003-01-01

(Pyridine)(tetrahydroborato)zinc complex, (Zn(BH 4 ) 2 (py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and α,β-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent

Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6cadmate(II dihydrate

Directory of Open Access Journals (Sweden)

Najmeh Firoozi

2008-10-01

Full Text Available In the title compound, (C4H14N2[Cd(C7H3NO42]·2H2O, the CdII ion is coordinated by four O atoms [Cd—O = 2.2399 (17–2.2493 (17 Å] and two N atoms [Cd—N = 2.3113 (15 and 2.3917 (15 Å] from two tridentate pyridine-2,6-dicarboxylato ligands in a distorted octahedral geometry. The uncoordinated water molecules are involved in O—H...O and N—H...O hydrogen bonds, which contribute to the formation of a three-dimensional supramolecular structure, along with π–π stacking interactions [centroid–centroid distances of 3.5313 (13 and 3.6028 (11 Å between the pyridine rings of neighbouring dianions].

Moisture resistant and anti-reflection optical coatings produced by plasma polymerization of organic compounds

Science.gov (United States)

Hollahan, J. R.; Wydeven, T.

1975-01-01

The need for protective coatings on critical optical surfaces, such as halide crystal windows or lenses used in spectroscopy, has long been recognized. It has been demonstrated that thin, one micron, organic coatings produced by polymerization of flourinated monomers in low temperature gas discharge (plasma) exhibit very high degrees of moisture resistence, e.g., hundreds of hours protection for cesium iodide vs. minutes before degradation sets in for untreated surfaces. The index of refraction of these coatings is intermediate between that of the halide substrate and air, a condition for anti-reflection, another desirable property of optical coatings. Thus, the organic coatings not only offer protection, but improved transmittance as well. The polymer coating is non-absorbing over the range 0.4 to 40 microns with an exception at 8.0 microns, the expected absorption for C-F bonds.

Polymer Concentration-Controlled Substrate Specificity in Solvolysis of p-Nitrophenyl Alkanoates Catalyzed by 4-(Dialkylamino)pyridine- Functionalized Polymer in Aqueous Methanol Solution

National Research Council Canada - National Science Library

Wang, Guang-Jia

1996-01-01

The substrate specificity in solvolysis reactions of p-nitrophenyl alkanoates 2 (n=2-18) catalyzed by 4-(dialkylamino)pyridine-functionalized polymer 1 can be controlled by the concentration of 1 in 1...

Pharmacokinetics of vinyl chloride in the rat

International Nuclear Information System (INIS)

Bolt, H.M.; Laib, R.J.; Kappus, H.; Buchter, A.

1977-01-01

When rats are exposed to [ 14 C]vinyl chloride in a closed system, the vinyl chloride present in the atmosphere equilibrates with the animals' organism within 15 min. The course of equilibration could be determined using rats which had been given 6-nitro-1,2,3-benzothiadiazole. This compound completely blocks metabolism of vinyl chloride. The enzymes responsible for metabolism of vinyl chloride are saturated at an atmospheric concentration of vinyl chloride of 250 ppm. Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides. This may be consistent with the theory that a reactive, shortly living metabolite which occurs in low concentration only, may be responsible for the toxic effects of vinyl chloride

Metal doped polymer films prepared by simultaneous plasma polymerization of tetrafluoromethane and evaporation of gold

Energy Technology Data Exchange (ETDEWEB)

Martinu, L.; Biederman, H. (Karlova Univ., Prague (Czechoslovakia). Fakulta Matematicko-Fyzikalni); Zemek, J. (Ceskoslovenska Akademie Ved, Prague. Fyzikalni Ustav)

The incorporation of gold from an evaporation source during plasma polymerization of tetrafluoromethane CF/sub 4/ in an RF (20 MHz) glow discharge excited by means of a planar magnetron has been investigated. Optical emission spectroscopy was used to monitor the deposition process in situ. The structure of the films was studied by transmission electron microscopy (TEM) observations. The sheet resistance and optical transmission measurements have been performed showing a dramatic influence of gold concentration on the film properties. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) analysis were used for determining the concentration depth profiles through the films. It has been shown that the presence of gold in the layers substantially reduces the fluorine content. The effect of various gold incorporation methods on the film characteristics has been discussed.

Surprising transformation of a block copolymer into a high performance polystyrene ultrafiltration membrane with a hierarchically organized pore structure

KAUST Repository

Shevate, Rahul; Kumar, Mahendra; Karunakaran, Madhavan; Canlas, Christian; Peinemann, Klaus-Viktor

2018-01-01

) block from self-assembled poly(styrene)-b-poly(4-vinyl pyridine) (PS-b-P4VP) membranes through the formation of an unstable pyridinium intermediate in an alkaline medium. During this process, the confined swelling and controlled degradation produced a

Study of the influence of the molecular structure of vinyl compounds on their ability to form polymer films by electro-polymerization under cathodic polarisation

International Nuclear Information System (INIS)

Deniau, Guy

1990-01-01

This research thesis addresses the study of new vinyl compounds, and aims at improving knowledge on the interaction between metal and a vinyl molecule under an intense electric field (the field of the double electrochemical layer), and more particularly at studying the influence of the molecular structure of the vinyl compound as well as the occurring reactions. After a first part presenting physical-chemical principles and knowledge which govern the whole set of reactions which are occurring within an electrolysis reactor, and a brief historical overview, this research thesis proposes a presentation of molecules which have been chosen for this study (vinyl compounds) and a justification of this choice. The author also presents the experimental device and describes the process implementation. Then, he presents and analyses experimental results. It appears that only some studied molecules result in the formation of polymer film [fr

Hydrolysis of strained bridgehead bicyclic vinyl ethers and sulfides

International Nuclear Information System (INIS)

Chwang, W.K.; Kresge, A.J.; Wiseman, J.R.

1979-01-01

Rates of hydrolysis of the bridgehead bicyclic vinyl ether 9-oxabicyclo[3.3.1]non-1-ene(6) and its vinyl sulfide counterpart 9-thiabicyclo[3.3.1]non-1-ene(7), catalyzed by the hydronium ion, were measured in H 2 O and in D 2 O solution. These data give isotope effects, k/sub H//k/sub D/ = 2.4 and 1.9 respectively, which show that these reactions occur by the normal, rate-determining carbon protonation, mechanism. The vinyl ether 6 is less reactive than its olefin analogue, bicyclo[3.3.1]non-1-ene (relative rate 1:1/1400), as may have been expected for a constrained bicyclic system such as this, where stabilization of the bridgehead carbocation intermediate by conjugation with oxygen is severely impaired. The vinyl sulfide 7, however, is even less reactive than the vinyl ether (relative rates 1:1/140); this is a remarkable result in view of the fact that conjugation between the sulfur atom and the cationic center is presumably also strongly inhibited. 1 figure, 3 tables

Crystal structure of poly[[hexaqua-1κ4O,2κ2O-bis(μ3-pyridine-2,4-dicarboxylato-1κO2:2κ2N,O2′;1′κO4cobalt(IIstrontium(II] dihydrate

Directory of Open Access Journals (Sweden)

Zhaojun Yu

2015-09-01

Full Text Available In the title polymeric complex, {[CoSr(C7H3NO42(H2O6]·2H2O}n, the CoII ion, which is situated on a crystallographic centre of inversion, is six-coordinated by two O atoms and two N atoms from two pyridine-2,4-dicarboxylate (pydc2− ligands and two terminal water molecules in a slightly distorted octahedral geometry, to form a trans-[Co(pydc2(H2O2]2− unit. The SrII ion, situated on a C2 axis, is coordinated by four O atoms from four pydc2− ligands and four water molecules. The coordination geometry of the SrII atom can be best described as a distorted dodecahedron. Each SrII ion bridges four [Co(pydc2(H2O2]2− units by four COO− groups of four pydc2− ligands to form a three-dimensional network structure. Two additional solvent water molecules are observed in the crystal structure and are connected to the three-dimensional coordination polymer by O—H...O hydrogen bonds. Further intra- and intermolecular O—H...O hydrogen bonds consolidate the overall structure.

Permanent hydrophilic modification of polypropylene and poly(vinyl alcohol) films by vacuum ultraviolet radiation

Energy Technology Data Exchange (ETDEWEB)

Belmonte, Guilherme Kretzmann [Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Charles, German [Centro de Química Aplicada (CEQUIMAP), Facultad de Ciencias Químicas, Unversidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba 5000 (Argentina); Strumia, Miriam Cristina [Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, IPQA-Conicet, Haya de la Torre y Medina Allende, Edificio de Ciencias II, Ciudad Universitaria, Córdoba 5000 (Argentina); Weibel, Daniel Eduardo, E-mail: danielw@iq.ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil)

2016-09-30

Highlights: • Polypropylene and Poly(vinyl alcohol) were surface modified by vacuum ultraviolet (VUV) irradiation. • The hydrophilicity of the treated films was permanent and resisted aging for several months. • Grafting of styrene monomer was only observed in the VUV irradiated regions. • The obtained results showed the potential in the use of VUV treatment for surface modification and processing of polymers which lack chromophores in the UV region. - Abstract: Polypropylene (PP) and Poly(vinyl alcohol) (PVA) both synthetics polymers but one of them biodegradable, were surface modified by vacuum ultraviolet (VUV) irradiation. After VUV irradiation in an inert nitrogen atmosphere, the films were exposed to oxygen gas. The treated films were characterized by water contact angle measurements (WCA), optical profilometry, FTIR-ATR, XPS, UPS and NEXAFS techniques. PP and PVA VUV-treated films reached superhydrophilic conditions (WCAs <10°) in about 30 min of irradiation under our experimental conditions. It was observed that when the WCAs reached about 35–40° the hydrophilicity was permanent in both polymers. These results contrasted with typical plasma treatments were a rapid hydrophobic recovery with aging time is usually observed. UPS and XPS data showed the presence of new functionalities on the PP and PVA surfaces that were assigned to COO, C=O, C−O and C=C functional groups. Finally, grafting of styrene (ST) as a typical monomer was tested on PP films. It was confirmed that only in the VUV irradiated region an efficient grafting of ST or polymerized ST was found. Outside the irradiated regions no ST grafted was observed. Our results showed the potential use of VUV treatment for surface modification and processing of polymers which lack chromophores in the UV region.

Synthesis and characterization of foldable and magnetic field-sensitive, freestanding poly(vinyl acetate)/poly(vinyl chloride)/polyfuran composite and nanocomposite films

Energy Technology Data Exchange (ETDEWEB)

Sarıtaş, Sevilay; Eşsiz, Serpil; Sarı, Bekir, E-mail: bsari@gazi.edu.tr

2017-07-01

Highlights: • In this study, ternary composite/nanocomposite films were synthesized. • Magnetic field-sensitive folding films were prepared without any elastomer. • Morphological studies show that all composite films have a smooth surface. • The ternary composites/nanocomposite show improved thermal stability compared to the pure PF. - Abstract: In this study, polyfuran and poly(vinyl acetate)/poly(vinyl chloride)/polyfuran ternary composites were synthesized via the chemical polymerization method. The temperature and magnetic field–sensitive novel composites and the nanocomposite were obtained in the form of powders and films. It was observed that the prepared novel conductive films have superior properties at a certain temperature range (25–50 °C) such as bending and folding. The structural properties, thermal behavior, surface morphology, internal structure, and surface roughness of the prepared samples were investigated by various characterization techniques. The conductivities of the samples were measured at room temperature and different temperatures by the four-point technique. X-ray Diffraction analysis results demonstrated that the PF and composites have an amorphous structure, whereas the nanocomposite is in crystalline form. The saturation magnetization (Ms) values of the magnetite and nanocomposite were found to be 58.9 and 5.3 emu g{sup −1}, respectively. It was found that magnetite-doped nanocomposite has superparamagnetic properties at room temperature.

Control of work function of graphene by plasma assisted nitrogen doping

International Nuclear Information System (INIS)

Akada, Keishi; Terasawa, Tomo-o; Imamura, Gaku; Obata, Seiji; Saiki, Koichiro

2014-01-01

Nitrogen doping is expected to provide several intriguing properties to graphene. Nitrogen plasma treatment to defect-free and defective highly oriented pyrolytic graphite (HOPG) samples causes doping of nitrogen atom into the graphene layer. Nitrogen atoms are initially doped at a graphitic site (inside the graphene) for the defect-free HOPG, while doping to a pyridinic or a pyrrolic site (edge of the graphene) is dominant for the defective HOPG. The work function of graphene correlates strongly with the site and amount of doped nitrogen. Nitrogen atoms doped at a graphitic site lower the work function, while nitrogen atoms at a pyridinic or a pyrrolic site increase the work function. Control of plasma treatment time and the amount of initial defect could change the work function of graphite from 4.3 eV to 5.4 eV, which would open a way to tailor the nature of graphene for various industrial applications

Field and laboratory determination of a poly(vinyl/vinylidene chloride) additive in brick mortar.

Science.gov (United States)

Law, S L; Newman, J H; Ptak, F L

1990-02-01

A polymerized vinyl/vinylidene chloride additive, used in brick mortar during the 60s and 70s, is detected at the building site by the field method, which employs a commercially available chloride test strip. The field test results can then be verified by the laboratory methods. In one method, total chlorine in the mortar is determined by an oxygen-bomb method and the additive chloride is determined by difference after water-soluble chlorides have been determined on a separate sample. In the second method, the polymerized additive is extracted directly from the mortar with tetrahydrofuran (THF). The difference in weight before and after extraction of the additive gives the weight of additive in the mortar. Evaporation of the THF from the extract leaves a thin film of the polymer, which gives an infrared "fingerprint" spectrum characteristic of the additive polymer.

Initial biocompatibility of plasma polymerized hexamethyldisiloxane films with different wettability

Science.gov (United States)

Krasteva, N. A.; Toromanov, G.; Hristova, K. T.; Radeva, E. I.; Pecheva, E. V.; Dimitrova, R. P.; Altankov, G. P.; Pramatarova, L. D.

2010-11-01

Understanding the relationships between material surface properties, behaviour of adsorbed proteins and cellular responses is essential to design optimal material surfaces for tissue engineering. In this study we modify thin layers of plasma polymerized hexamethyldisiloxane (PPHMDS) by ammonia treatment in order to increase surface wettability and the corresponding biological response. The physico-chemical properties of the polymer films were characterized by contact angle (CA) measurements and Fourier Transform Infrared Spectroscopy (FTIR) analysis.Human umbilical vein endothelial cells (HUVEC) were used as model system for the initial biocompatibility studies following their behavior upon preadsorption of polymer films with three adhesive proteins: fibronectin (FN), fibrinogen (FG) and vitronectin (VN). Adhesive interaction of HUVEC was evaluated after 2 hours by analyzing the overall cell morphology, and the organization of focal adhesion contacts and actin cytoskeleton. We have found similar good cellular response on FN and FG coated polymer films, with better pronounced vinculin expression on FN samples while. Conversely, on VN coated surfaces the wettability influenced significantly initial celular interaction spreading. The results obtained suggested that ammonia plasma treatment can modulate the biological activity of the adsorbed protein s on PPHMDS surfaces and thus to influence the interaction with endothelial cells.

Polymeric hydrogels containing complexant agents for retention of pollutants containing thorium

International Nuclear Information System (INIS)

Oliveira, Maria Jose A.; Carreiro, Julio C.; Parra, Duclerc F.; Lugao, Ademar B.

2005-01-01

The hydrogels of poly(N-vinyl-2-pyrrolidone) (PVP), constituted of around 90% of water , show properties of retaining great amount of water and consequently can also retain substances that were made soluble, with either particular or specific reactive properties. In the light of this, these matrixes can be used as support for both capture and retention of radioactive substances of contaminated surfaces. Modified hydrogels containing complexant agents had been obtained in solution, in order to capture contaminated substances. The study of the ionizing radiation effect in polymer is of great interest not only to the development of materials which operate in conditions of radiation but also to the usage of the technique with purpose of both polymeric structure modification and acquisition of new materials. Membranes of hydrogels have been obtained with poly(N-vinyl-2-pyrrolidone)-PVP, polyethyleneglycol (PEG), Agar and several concentrations of ethylenediaminetetraacetic acid (EDTA), and sodium citrate. Theses samples were irradiated in 60 Co source, 15 kGy/h dose and submitted to thermal characterization in a Mettler-Toledo SDTA/851 equipment. The hydrogels membranes polymerized by radiation were put in contact with thorium nitrate solution, dehydrated and calcined, after that their ashes were analyzed. In the case of solution containing thorium were analyzed by spectrophotometric. (author)

Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

International Nuclear Information System (INIS)

Navaneetha Pandiyaraj, K.; Ram Kumar, M.C.; Arun Kumar, A.; Padmanabhan, P.V.A.; Deshmukh, R.R.; Bah, M.; Ismat Shah, S.; Su, Pi-Guey; Halleluyah, M.; Halim, A.S.

2016-01-01

Graphical abstract: - Highlights: • Developed low cost cold atmospheric plasma reactor for plasma polymerization technique. • Surface of the PP film was modified by grafting of AAc and PEG by CAPP polymerization. • Biomolecules of chitosan, insulin and heparin were immobilized on surface of PEG-AAc grafted PP films. • The surface modified PP films were characterized by various techniques. • The plasma polymerized and immobilized film reveals substantial blood compatibility. - Abstract: Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as O−C=O, C=O, C−N and S−S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was

Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

Energy Technology Data Exchange (ETDEWEB)

Navaneetha Pandiyaraj, K., E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Ram Kumar, M.C.; Arun Kumar, A. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Padmanabhan, P.V.A. [PSN College of Engineering and Technology, Tirunelveli 627 152 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Bah, M.; Ismat Shah, S. [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Halleluyah, M.; Halim, A.S. [School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

2016-05-01

Graphical abstract: - Highlights: • Developed low cost cold atmospheric plasma reactor for plasma polymerization technique. • Surface of the PP film was modified by grafting of AAc and PEG by CAPP polymerization. • Biomolecules of chitosan, insulin and heparin were immobilized on surface of PEG-AAc grafted PP films. • The surface modified PP films were characterized by various techniques. • The plasma polymerized and immobilized film reveals substantial blood compatibility. - Abstract: Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as O−C=O, C=O, C−N and S−S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was

Pyridine 2,4-Dicarboxylic Acid Suppresses Tomato Seedling Growth

Directory of Open Access Journals (Sweden)

Sotirios Fragkostefanakis

2018-01-01

Full Text Available Pyridine 2,4-dicarboxylic acid is a structural analog of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μM of PDCA decreased hydroxyproline content in roots while only the 250 μM treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μM PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μM which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analog. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

Pyridine 2,4-dicarboxylic acid suppresses tomato seedling growth

Science.gov (United States)

Fragkostefanakis, Sotirios; Kaloudas, Dimitrios; Kalaitzis, Panagiotis

2018-01-01

Pyridine 2,4-dicarboxylic acid is a structural analogue of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μΜ of PDCA decreased hydroxyproline content in roots while only the 250 μΜ treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μΜ PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs) are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μΜ which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analogue. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

Thermometric titration of acids in pyridine.

Science.gov (United States)

Vidal, R; Mukherjee, L M

1974-04-01

Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

Large enhanced dielectric permittivity in polyaniline passivated core-shell nano magnetic iron oxide by plasma polymerization

Energy Technology Data Exchange (ETDEWEB)