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Sample records for butylene polystyrene synthesis

  1. Synthesis by ATRP of poly(ethylene-co-butylene)-block-polystyrene, poly(ethylene-co-butylene)-block-poly(4-acetoxystyrene) and its hydrolysis product poly(ethylene-co-butylene)-block-poly(hydroxystyrene)

    DEFF Research Database (Denmark)

    Jankova, Katja; Kops, Jørgen; Chen, Xianyi

    1999-01-01

    Diblock copolymers of poly(ethylene-co-butylene) and polystyrene or poly(4-acetoxystyrene) are synthesized by atom transfer radical polymerization (ATRP) using a 2-bromopropionic ester macroinitiator prepared from commercial monohydroxyl functional narrow dispersity hydrogenated polybutadiene...... (Kraton Liquid Polymer, L-1203). ATRP carried out in bulk and in xylene solution with cuprous bromide and two different complexing agents 2,2'-bipyridine (bipy) and 1,1,4,7,10,10-hexamethyltriethylenetetraamine (HMTETA) yielded well-defined diblock copolymers with polydispersities around 1,3. The diblock...... copolymer with poly(4-acetoxystyrene) was hydrolyzed to the corresponding poly(4-hydroxystyrene) sequence....

  2. Effect of planar extension on the structure and mechanical properties of polystyrene-poly(ethylene-¤co¤-butylene)-polystyrene triblock copolymers

    DEFF Research Database (Denmark)

    Daniel, C.; Hamley, I.W.; Mortensen, K.

    2000-01-01

    Two thermoplastic poly(styrene)-poly(ethylene-co-butylene) -poly(styrene) triblock copolymers containing either spherical or cylindrical poly(styrene) microdomains were pre-oriented through extensional flow. Small angle neutron scattering (SANS) measurements revealed that the pre-oriented triblock...

  3. Study of the mechanical properties of Acrylonitrile Butadiene Styrene - High Impact Polystyrene blends with Styrene Ethylene Butylene Styrene

    OpenAIRE

    PEYDRO Miguel Angel; JUAREZ David; Sanchez-Caballero, Samuel; PARRES Francisco

    2013-01-01

    A binary blend Acrylonitrile Butadiene Styrene ¿ High Impact Polystyrene (ABS-HIPS 50% wt) was prepared on a twin-screw extruder at 190-210 oC. The different mechanical properties were then analyzed using tensile strength and impact tests. The analysis of mechanical properties showed a decrease in elongation at break and impact strength. On the other hand, we have prepared ternary blends of ABS-HIPS- Styrene Ethylene Butylene Styrene (SEBS), varying the percentage of SEBS from 10 to 30 %wt us...

  4. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    NARCIS (Netherlands)

    Neppalli, Ramesh; Causin, Valerio; Benetti, Edmondo Maria; Ray, Suprakas Sinha; Esposito, Antonella; Wanjale, Santosh; Birajdar, Mallinath; Saiter, Jean-Marc; Marigo, Antonio

    2014-01-01

    In this work, composite polystyrene/titanium dioxide (PS/TiO2) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior of such materials were investigated, finding that, as a

  5. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    CSIR Research Space (South Africa)

    Neppalli, R

    2014-01-01

    Full Text Available In this work, composite polystyrene/titanium dioxide (PS/TiO(sub2)) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior...

  6. Synthesis and interfacial behavior of polystyrene-polysaccharide diblock copolymers

    NARCIS (Netherlands)

    Bosker, W.T.E.; Ágoston, K.; Cohen Stuart, M.A.; Norde, W.; Timmermans, J.W.; Slaghek, T.M.

    2003-01-01

    Linear block copolymers of polystyrene and polysaccharide were synthesized using a block synthesis method with amino-terminated polystyrene and sodium cyanoborohydride as reducing agent. Different types of polysaccharides, dextrans, and maltodextrins with various molecular weights were used. IR

  7. Computational Modeling of Polystyrene-b-(ethylene-co-butylene)-b-styrene and Mineral Oil Gels and Nanocomposites

    Science.gov (United States)

    Chantawansri, T. L.; Berg, M.; Mrozek, R.; Stokes, K.; Henz, B.; Chung, P.; Beyer, F.; Lenhart, J.; Andzelm, J. W.

    2010-03-01

    There has been substantial interest in thermoplastic elastomer (TPE) gels composed of poly(styrene-b-(ethylene-co-butylene)-b-styrene)(SEBS) and hydrocarbon oils. Although the effects of adding nanoparticles on TPE gels is relatively unexplored, research in polymer nanocomposites have shown that the addition of nanoparticles enhanced physical properties. The microstructure of such a system is dependent on a variety of parameters such as block copolymer and nanoparticle concentrations, temperature, nanoparticle size, and nanoparticle interaction; thus to perform an extensive study of phase space, mesoscale modeling should be used in conjunction with the experimentation. To complement our experimental system, mesoscale modeling of this TPE gel and the corresponding nanocomposite are preformed using dynamic density functional theory and self consistent field theory through Materials Studio, where morphology of the system is studied as a function of various parameters and conditions. The validity of the computational methods has been confirmed for a number of experimental results, and subsequently has been used to explore a larger design space than is accessible solely through experimental methods.

  8. Study of the thermal properties of Acrylonitrile Butadiene Styrene - High Impact Polystyrene blends with Styrene Ethylene Butylene Styrene

    OpenAIRE

    PEYDRO Miguel Angel; JUAREZ David; Sanchez-Caballero, Samuel; PARRES Francisco

    2013-01-01

    A binary blend Acrylonitrile Butadiene Styrene ¿ High Impact Polystyrene (ABS-HIPS 50% wt) was prepared on a twin-screw extruder at 190-210 oC. The different properties were then analyzed using melt flow index (MFI), thermogravimetric analysis (TGA), and Fourier Transform Infrared spectroscopy (FTIR). FTIR analysis indicated heterogeneous distribution of the blend in injected pieces and SEM micrographs show heterogeneous distribution of both phase (ABS and HIPS). On the other hand, we have pr...

  9. Performance of polyethylene based radiation grafted anion exchange membrane with polystyrene-b-poly (ethylene/butylene)-b-polystyrene based ionomer using NiCo2O4 catalyst for water electrolysis

    Science.gov (United States)

    Gupta, Gaurav; Scott, Keith; Mamlouk, Mohamed

    2018-01-01

    A soluble anion exchange ionomer with high OH- ion conductivity comparable to that of H+ conductivity of Nafion is synthesised by chloromethylation of polystyrene-b-poly (ethylene/butylene)-b-polystyrene (SEBS) and used with NiCo2O4 electro-catalyst for water electrolysis. The ionomer has an ion exchange capacity of 1.9 mmol g-1 and ionic conductivity of 0.14 S cm-2 at 50 °C. The cell voltage at 20 °C at 100 mA cm-2 is 1.77 and 1.72 V in, 0.1 and 1.0 M NaOH, respectively, for an optimum loading of 10 mg cm-2 NiCo2O4. At 10 mg cm-2 NiCo2O4 electrolyser cell performance is at least equal to or superior to that of IrO2 at 2 mg cm-2 with excellent stability over 1 h. When the catalyst is sprayed on the GDL instead of CCM, the performance is further improved to 1.65 V at 100 mA cm-2 at 60 °C & 0.1 M KOH. The limited AEM electrolyser performance when operating with deionised water in comparison to PEM and alkaline electrolyser arises from the sluggish OER in the AEM environment equivalent to pH of 11.5 and the two orders of magnitude lower HER activity with respect to acid medium combined with the high Tafel slope of 120 mV dec-1.

  10. Synthesis, magnetic and spectral studies on polystyrene-anchored ...

    Indian Academy of Sciences (India)

    The polystyrene-anchored coordination compounds have been characterized by elemental analysis, IR, reflectance, ESR and magnetic susceptibility measurements. The per cent reaction conversion of polystyrene anchored Schiff base to polystyrene supported coordination compounds lies between 28.98 and 85.9.

  11. Improved synthesis of polystyrene-poly(ethylene oxide)-heparin block copolymers

    NARCIS (Netherlands)

    Vulic, I.; Loman, A.J.B.; Feijen, Jan; Okano, T.; Kim, S.W.

    1990-01-01

    A novel procedure for the synthesis of block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic block of poly(ethylene oxide) and a bioactive block of nitrous acid-degraded heparin was developed. Amino-semitelechelic polystyrene was prepared by anionic polymerization of styrene

  12. Enzymatic Synthesis of a Bio-Based Copolyester from Poly(butylene succinate) and Poly((R)-3-hydroxybutyrate): Study of Reaction Parameters on the Transesterification Rate.

    Science.gov (United States)

    Debuissy, Thibaud; Pollet, Eric; Avérous, Luc

    2016-12-12

    The enzyme-catalyzed synthesis of fully biobased poly(3-hydroxybutyrate-co-butylene succinate) (poly(HB-co-BS)) copolyesters is reported for the first time. Different Candida antarctica lipase B (CALB)-catalyzed copolyesters were produced in solution, via a one-step or a two-step process from 1,4-butanediol, diethyl succinate, and synthesized telechelic hydroxylated poly(3-hydroxybutyrate) oligomers (PHB-diol). The influence of the ester/hydroxyl functionality ratio, catalyst amount, PHB-diol oligomer chain length, hydroxybutyrate (HB) and butylene succinate (BS) contents, and the nature of the solvent were investigated. The two-step process allowed the synthesis of copolyesters of high molar masses (M n up to 18 000 g/mol), compared to the one-step process (M n ∼ 8000 g/mol), without thermal degradation. The highest molar masses were obtained with diphenyl ether as solvent, compared with dibenzyl ether or anisole. During the two-step process, the transesterification rate between the HB and BS segments (i) increased with increasing amount of catalyst and decreasing molar mass of the PHB-diol oligomer, (ii) decreased when anisole was used as the solvent, and (iii) was not influenced by the HB/BS ratio. Tendencies toward block or random macromolecular architectures were observed as a function of the reaction time, the PHB-diol oligomer chain length, and the chosen solvent. Immobilized CALB-catalyzed copolyesters were thermally stable up to 200 °C. The crystalline structure of the poly(HB-co-BS) copolyesters depended on the HB/BS ratio and the average sequence length of the segments. The crystalline content, T m and T c decreased with increasing HB content and the randomness of the copolymer structure.

  13. Chemical Recycling of Expanded Polystyrene Waste: Synthesis of Novel Functional Polystyrene-Hydrazone Surface for Phenol Removal

    OpenAIRE

    Ali N. Siyal; Saima Q. Memon; Sajida Parveen; Asma Soomro; Khaskheli, Mazhar I.; Khuhawar, M.Y.

    2013-01-01

    Expanded polystyrene (EPS) waste was chemically recycled to a novel functional polystyrene-hydrazone (PSH) surface by acetylation of polystyrene (PS) and then condensation with phenyl hydrazine. The synthesized surface was characterized by the FT-IR and elemental analysis. Synthesized novel functional PSH surface was successfully applied for the treatment of phenol-contaminated industrial wastewater by solid-phase extraction. Multivariant sorption optimization was achieved by factorial design...

  14. Chemical Recycling of Expanded Polystyrene Waste: Synthesis of Novel Functional Polystyrene-Hydrazone Surface for Phenol Removal

    Directory of Open Access Journals (Sweden)

    Ali N. Siyal

    2013-01-01

    Full Text Available Expanded polystyrene (EPS waste was chemically recycled to a novel functional polystyrene-hydrazone (PSH surface by acetylation of polystyrene (PS and then condensation with phenyl hydrazine. The synthesized surface was characterized by the FT-IR and elemental analysis. Synthesized novel functional PSH surface was successfully applied for the treatment of phenol-contaminated industrial wastewater by solid-phase extraction. Multivariant sorption optimization was achieved by factorial design approach. 99.93% of phenol was removed from aqueous solution. FT-IR study showed the involvement of nitrogen of hydrazone moiety of synthesized surface for the uptake of phenol through the hydrogen bonding.

  15. Synthesis and characterization of a novel multiblock copolyester containing poly(ethylene succinate) and poly(butylene succinate)

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Qunying; He Yisong [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Zeng Jianbing, E-mail: zengjianbing@scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Huang Qing [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Wang Yuzhong, E-mail: yzwang@email.scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China)

    2011-11-01

    Highlights: {yields} High-molecular-weight biodegradable multiblock copolyester containing PBS and PES segments was achieved. {yields} PBS and PES are miscible with a single glass transition regardless of composition. {yields} The multiblock copolyester showed excellent tensile strength and elongation at break. {yields} The multiblock copolyester can serve as a potential substitute for conventional non-biodegradable commodity plastics. - Abstract: Multiblock copolyester (PBS-b-PES) containing poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was successfully synthesized by chain-extension of dihydroxyl terminated PBS (HO-PBS-OH) and PES (HO-PES-OH) using 1,6-hexmethylene diisocyanate (HDI) as a chain extender. The chemical structures, molecular weights, crystallization behaviors, thermal and mechanical properties of the copolyesters were characterized by proton nuclear magnetic resonance spectroscopy ({sup 1}H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), wide-angle X-ray diffraction (WAXD), tensile testing and hydrolytic degradation. High-molecular-weight copolyesters with M{sub w} more than 2.0 x 10{sup 5} g mol{sup -1} were easily obtained through chain-extension. The copolyesters showed a single glass transition temperature (T{sub g}) which increased with PES content. The melting point temperature (T{sub m}) and relative degree of crystallinity (X{sub c}) of the copolyesters decreased first and then increased with PES content. The copolyesters manifested excellent mechanical properties, for example, PBS{sub 5}-b-PES{sub 5} had fracture stress of 61.8 MPa and fracture strain of 1173%. The chain-extension reaction provided a very effective way to produce high molecular weight multiblock copolyesters.

  16. Synthesis of antibacterial amphiphilic elastomer based on polystyrene-block-polyisoprene-block-polystyrene via thiol-ene addition

    Energy Technology Data Exchange (ETDEWEB)

    Keleş, Elif, E-mail: elifkelesh@hotmail.com [Department of Chemistry, Bülent Ecevit University, Zonguldak 67100 (Turkey); Hazer, Baki, E-mail: bhazer2@yahoo.com [Department of Chemistry, Bülent Ecevit University, Zonguldak 67100 (Turkey); Cömert, Füsun B. [Department of Microbiology, Faculty of Medicine, Bülent Ecevit University, 67600 Zonguldak (Turkey)

    2013-04-01

    A new type of amphiphilic antibacterial elastomer has been described. Thermoplastic elastomer, polystyrene–block-polyisoprene–block-polystyrene (PS–b-PI–b-PS) triblock copolymer was functionalized in toluene solution by free radical mercaptan addition in order to obtain an amphiphilic antibacterial elastomer. Thiol terminated PEG was grafted through the double bonds of PS–b-PI–b-PS via free radical thiol-ene coupling reaction. The antibacterial properties of the amphiphilic graft copolymers were observed. The original and the modified polymers were used to create microfibers in an electro-spinning process. Topology of the electrospun micro/nanofibers were studied by using scanning electron microscopy (SEM). The chemical structures of the amphiphilic comb type graft copolymers were elucidated by the combination of elemental analysis, {sup 1}H NMR, {sup 13}C NMR, GPC and FTIR. - Graphical abstract: Double bonds of polyisoprene units in polystyrene–block-polyisoprene–block-polystyrene triblock copolymer were partially capped with PEG containing mercapto end group via thiol-ene addition in order to obtain antibacterial amphiphilic elastomer. Nano fibers from amphiphilic graft polymers solution were produced by electrospinning. The PEG grafted copolymer inhibits very effectively bacterial growth. Highlights: ► A commercial synthetic elastomer was grafted with PEG to obtain amphiphilic elastomer. ► Amphiphilic elastomer shows antibacterial properties. ► Electrospun micro fibers of the amphiphilic elastomer tend to globular formation.

  17. Synthesis in pilot plant scale and physical properties of sulfonated polystyrene

    Directory of Open Access Journals (Sweden)

    Martins Cristiane R.

    2003-01-01

    Full Text Available The homogenous sulfonation of polystyrene was developed in a pilot plant scale producing polymers with different sulfonation degrees (18 to 22 mole % of sulfonated styrene units. The reaction yield depends chiefly on the concentration ratio of acetyl sulfate and polystyrene. The morphological and thermal properties of the sulfonated polystyrene obtained by homogeneous sulfonation were studied by means of scanning electron microscopy, differential scanning calorimetry and thermogravimetry. The glass transition temperature of sulfonated polystyrene increases in relation to pure polystyrene and DCp was evaluated in order to confirm the strong interactions among the ~SO3H groups.

  18. Sonication-assisted synthesis of polystyrene (PS)/organoclay nanocomposites: influence of clay content

    Science.gov (United States)

    Suresh, Kelothu; Kumar, R. Vinoth; Kumar, Manish; Jeyapriya, M.; Anbarasan, R.; Pugazhenthi, G.

    2017-06-01

    This article presents the synthesis of a series of polystyrene (PS)/organoclay nanocomposite films consisting of different contents of clay (1-7 wt%) by sonication-coupled solvent-blending technique. The prepared PS nanocomposite films were characterized using various techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA). The XRD and TEM results revealed the formation of exfoliated nanocomposites at lower loading of organoclay (<5 wt%). The presence of various functional groups in the organoclay and PS/organoclay nanocomposite was verified by FTIR spectra. The thermal stability of PS nanocomposites was significantly improved as compared to pristine PS, which is evident from TGA analysis. When 10% mass loss was chosen as a point of reference, the thermal degradation temperature of PS nanocomposite holding 7 wt% of organoclay was found to be 30 °C more over pristine PS. The thermal kinetic parameters such as activation energy ( E a), pre-exponential factor ( A), and the order of reaction ( n) were determined by employing the Coats-Redfern model. Thermal degradation reaction mechanism of PS nanocomposites was also investigated.

  19. Synthesis and characterization of polystyrene-poly(ethylene oxide)-heparin block copolymers

    NARCIS (Netherlands)

    Vulić, I.; Okano, T.; Kim, S.W.; Feijen, Jan

    1988-01-01

    A procedure for the preparation of new block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic spacer-block of poly(ethylene oxide) and a bioactive block of heparin was investigated. Polystyrene with one amino group per chain was synthesized by free radical oligomerization of

  20. Synthesis of Well-Defined Polybenzamide-block-Polystyrene by Combination of Chain-Growth Condensation Polymerization and RAFT Polymerization.

    Science.gov (United States)

    Masukawa, Tomohiro; Yokoyama, Akihiro; Yokozawa, Tsutomu

    2009-08-18

    Well-defined diblock copolymers composed of poly(N-octylbenzamide) and polystyrene were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene with a polyamide chain transfer agent (CTA) prepared via chain-growth condensation polymerization. Synthesis of a dithioester-type macro-CTA possessing the polyamide segment as an activating group was unsatisfactory due to side reactions and incomplete introduction of the benzyl dithiocarbonyl unit. On the other hand, a dithiobenzoate-CTA containing poly(N-octylbenzamide) as a radical leaving group was easily synthesized, and the RAFT polymerization of styrene with this CTA afforded poly(N-octylbenzamide)-block-polystyrene with controlled molecular weight and narrow polydispersity. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Poly(Butylene Succinate) and Poly[(Butylene Succinate)-co-Adipate] Nanocomposites

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2012-01-01

    Full Text Available , and properties of nanoclay-containing composites of biodegradable poly(butylene succinate) (PBS) and poly[(butylene succinate)-co-adipate] (PBSA). Various nanocomposite structures arising from the incorporation of layered silicate particles, both pristine...

  2. Synthesis of polystyrene microspheres and functionalization with Pd(0) nanoparticles to perform bioorthogonal organometallic chemistry in living cells.

    Science.gov (United States)

    Unciti-Broceta, Asier; Johansson, Emma M V; Yusop, Rahimi M; Sánchez-Martín, Rosario M; Bradley, Mark

    2012-05-31

    We have developed miniaturized heterogeneous Pd(0)-catalysts (Pd(0)-microspheres) with the ability to enter cells, stay harmlessly within the cytosol and mediate efficient bioorthogonal organometallic chemistries (e.g., allylcarbamate cleavage and Suzuki-Miyaura cross-coupling). This approach is a major addition to the toolbox available for performing chemical reactions within cells. Here we describe a full protocol for the synthesis of the Pd(0)-microspheres from readily available starting materials (by the synthesis of size-controlled amino-functionalized polystyrene microspheres), as well as for their characterization (electron microscopy and palladium quantitation) and functional validation ('in solution' and 'in cytoplasm' conversions). From the beginning of the synthesis to functional evaluation of the catalytic device requires 5 d of work.

  3. Synthesis, Characterization and Gold Loading of Polystyrene-Poly(pyridyl methacrylate) Core-Shell Latex Systems

    NARCIS (Netherlands)

    Oláh, A.; Hempenius, Mark A.; Vancso, Gyula J.

    2004-01-01

    In this research, novel 3-(2-pyridyl)propyl methacrylate and 3-(3-pyridyloxy)propyl methacrylate monomers were synthesized and emulsion polymerized on colloidal polystyrene seeds, resulting in core–shell latex systems. The cores and the core–shell particles were characterized by static light

  4. Ionomeric membranes based on partially sulfonated poly(styrene) : synthesis, proton conduction and methanol permeation

    NARCIS (Netherlands)

    Picchioni, F.; Tricoli, V.; Carretta, N.

    2000-01-01

    Homogeneuosly sulfonated poly(styrene) (SPS) was prepared with various concentration of sulfonic acid groups in the base polymer. Membranes cast from these materials were investigated in relation to proton conductivity and methanol permeability in the temperature range from 20°C to 60°C. It was

  5. Synthesis of Hollow Conductive Polypyrrole Balls by the Functionalized Polystyrene as Template

    Directory of Open Access Journals (Sweden)

    Choo Hwan Chang

    2010-01-01

    Full Text Available We report the preparation of hollow spherical polypyrrole balls (HSPBs by two different approaches. In the first approach, core-shell conductive balls, CSCBs, were prepared with poly(styrene as core and polypyrrole (PPy as shell by in situ polymerization of pyrrole in the presence of polystyrene (PS latex particles. In the other approach, CSCBs were obtained by in situ copolymerization of pyrrole in the presence of PS(F with hydrophilic groups like anhydride, boronic acid, carboxylic acid, or sulfonic acid, and then HSPBs were obtained by the removal of PS or PS(F core from CSCBs. TEM images reveal the spherical morphology for HSPBs prepared from PS(F. The conductivity of CSCBs and HSPBs was in the range of 0.20–0.90 S/cm2.

  6. Synthesis of polystyrene, poly(styrene/4-vinylpyridine), poly(p-nitrostyrene) and poly(p-aminostyrene)-coated silica and their extraction capabilities for amphetamine

    Energy Technology Data Exchange (ETDEWEB)

    Sun Changmei; Zhang Shuanhong [School of Chemistry and Materials Science, Ludong University, Yantai, Shandong 264025 (China); Qu Rongjun, E-mail: qurongjun@eyou.com [School of Chemistry and Materials Science, Ludong University, Yantai, Shandong 264025 (China); Sun Tao; Zhang Ying; Zhang Xiang; Song Jingyang [School of Chemistry and Materials Science, Ludong University, Yantai, Shandong 264025 (China)

    2010-11-01

    Several novel organic-inorganic hybrid materials, including polystyrene-coated silica (SG-PS), poly(styrene/4-vinylpyridine)-coated silica (SG-PVP), poly(p-nitrostyrene)-coated silica (SG-PS-NO{sub 2}) and poly(p-aminostyrene)-coated silica (SG-PS-NH{sub 2}), were synthesized in order to improve the extraction methods of harmful stimulants via solid phase extraction. The materials were characterized using infrared spectra (IR), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area measurement and thermogravimetric analysis (TG). The application of the new materials in solid phase extraction columns to extract methamphetamine revealed that the extraction capability of poly(styrene/4-vinylpyridine)-coated silica is the best among the four materials, which provides novel supporter materials for extracting amphetamine-derived drugs.

  7. A facile and efficient synthesis of polystyrene/gold-platinum composite particles and their application for aerobic oxidation of alcohols in water.

    Science.gov (United States)

    Li, Yunxing; Gao, Yan; Yang, Cheng

    2015-05-04

    Herein we develop a facile and effective method for the synthesis of composite particles composed of polystyrene microspheres decorated with gold-platinum alloy nanoparticles, which exhibited excellent catalytic activity and recyclability for 1-phenylethanol oxidation under mild conditions (without a base, air as an oxidant, in water, at 40 °C).

  8. Synthesis and Characterization of Zinc Borate Nanowhiskers and Their Inflaming Retarding Effect in Polystyrene

    Directory of Open Access Journals (Sweden)

    Pingqiang Gao

    2015-01-01

    Full Text Available Zinc borate nanowhiskers 4ZnO·B2O3·H2O were in situ successfully synthesized via one-step precipitation reaction. A set of experiments was performed to evaluate the influence of reaction temperature. Increasing the temperature up to 70°C led to the high purity of zinc borate nanowhiskers with a monoclinic crystal structure measuring 50 nm to 100 nm in diameter and approximately 1 µm in length. However, higher temperature decreases the crystallization due to the emergence of other styles of zinc borate. Flame-resistant nanocomposites of polystyrene and zinc borate nanowhiskers were also successfully synthesized. The samples were investigated by XRD, FESEM, FTIR, and TG. The mechanical properties of the composites were also tested. The incorporation of zinc borate nanowhiskers improved the thermal and mechanical properties for polystyrene. FESEM images show that zinc borate nanowhiskers increased the smoothness of composites. The composites presented good responsive behavior in relation to LOI (limiting oxygen index allowing them to be suitable for green flame retardants.

  9. Green Synthesis, Characterization, and Antibacterial Activity of Silver/Polystyrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Manal A. Awad

    2015-01-01

    Full Text Available A novel, nontoxic, simple, cost-effective and ecofriendly technique was used to synthesize green silver nanoparticles (AgNPs. The AgNPs were synthesized using orange peel extract as a reducing agent for silver nitrate salt (AgNO3. The particle size distribution of AgNPs was determined by Dynamic Light Scattering (DLS. The average size of silver nanoparticles was 98.43 nm. The stable dispersion of silver nanoparticles was added slowly to polystyrene solution in toluene maintaining the temperature at 70°C. The AgNPs/polystyrene (PS nanocomposite solution was cast in a petri dish. The silver nanoparticles encapsulated within polymer chains were characterized by X-ray diffraction (XRD and Scanning Electron Microscopy (SEM equipped with Energy Dispersive Spectroscopy (EDS in addition to Transmission Electron Microscopy (TEM. The green AgNPs/PS nanocomposite film exhibited antimicrobial activity against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae and Salmonella, and Gram-positive bacteria Staphylococcus aureus. Thus, the key findings of the work include the use of a safe and simple AgNPs/PS nanocomposite which had a marked antibacterial activity which has a potential application in food packaging.

  10. Synthesis and characterization of superhydrophobic and superparamagnetic film based on maghemite-polystyrene composite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.D. [School of Materials Science and Engineering, Shandong Polytechnic University, Key Laboratory of Processing and Testing Technology of Glass Functional Ceramics of Shandong Province, Daxue Road, Western University Science Park, Jinan 250353 (China); Liu, W.L., E-mail: wlliu@sdu.edu.cn [School of Materials Science and Engineering, Shandong Polytechnic University, Key Laboratory of Processing and Testing Technology of Glass Functional Ceramics of Shandong Province, Daxue Road, Western University Science Park, Jinan 250353 (China); Xu, W.H.; Yao, J.S.; Zhao, L. [School of Materials Science and Engineering, Shandong Polytechnic University, Key Laboratory of Processing and Testing Technology of Glass Functional Ceramics of Shandong Province, Daxue Road, Western University Science Park, Jinan 250353 (China); Wang, X.Q.; Wu, Y.Z. [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Maghemite nanoparticles were coated with silica. Black-Right-Pointing-Pointer Polystyrene was grafted onto the surface of silica coated maghemite. Black-Right-Pointing-Pointer The rough surface shows superhydrophobic and superparamagnetic properties. - Abstract: We combine two abilities: the superhydrophobicity of lotus leaf and the magnetic property of {gamma}-Fe{sub 2}O{sub 3}. A superhydrophobic and superparamagnetic polystyrene/silica/maghemite (PS/SiO{sub 2}/{gamma}-Fe{sub 2}O{sub 3} (PSVSF)) film was prepared by a three-step chemical procedure at mild conditions. The products exhibited superhydrophobicity and superparamagnetism after coating and modifying. Because PS and SiO{sub 2} supplied the low surface energy and roughness, respectively. In addition, the classic and a modified Cassie-Baxter relation were applied on the PSVSF films to verify the superhydrophobic performance. It indicates that the obtained superhydrophobic and superparamagnetic films are promising materials for numerous potential applications fields, including aerospace, electronic, biomedical, martial and defense-related areas.

  11. Synthesis and characterization of polystyrene coated iron oxide nanoparticles and asymmetric assemblies by phase inversion

    KAUST Repository

    Xie, Yihui

    2014-09-02

    Films with a gradient concentration of magnetic iron oxide nanoparticles are reported, based on a phase inversion membrane process. Nanoparticles with ∼13 nm diameter were prepared by coprecipitation in aqueous solution and stabilized by oleic acid. They were further functionalized by ATRP leading to grafted polystyrene brush. The final nanoparticles of 33 nm diameter were characterized by TGA, FTIR spectroscopy, GPC, transmission electron microscopy, and dynanmic light scattering. Asymmetric porous nanoparticle assemblies were then prepared by solution casting and immersion in water. The nanocomposite film production with functionalized nanoparticles is fast and technically scalable. The morphologies of films were characterized by scanning electron microscopy and atomic force microscopy, demonstrating the presence of sponge-like structures and finger-like cavities when 50 and 13 wt % casting solutions were, respectively, used. The magnetic properties were evaluated using vibrating sample magnetometer.

  12. Synthesis of Hollow Silica Nanospheres by Sacrificial Polystyrene Templates for Thermal Insulation Applications

    Directory of Open Access Journals (Sweden)

    Linn Ingunn C. Sandberg

    2013-01-01

    Full Text Available Monodisperse polystyrene (PS spheres with controllable size have been synthesized by a straight forward and simple procedure. The as-synthesized PS spheres have a typical diameter ranging from ~180 nm to ~900 nm, where a reduced sphere size is obtained by increasing the polyvinylpyrrolidone (PVP/styrene weight ratio. The PS spheres function as sacrificial templates for the fabrication of hollow silica nanospheres (HSNSs for thermal insulation applications. By modifying the silica coating process, HSNSs with different surface roughness are obtained. All resulting HSNSs show typically a thermal conductivity of about 20 mW/(mK, indicating that the surface phonon scattering is probably not significant in these HSNS samples.

  13. Synthesis and Characterization of Poly(3-hexylthiophene-b-Polystyrene for Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Kenji Ogino

    2011-03-01

    Full Text Available Poly(3-hexylthiophene-block-polystyrene (P3HT-b-PS was synthesized by Suzuki coupling reaction between P3HT and PS, prepared by Grignard metathesis polymerization and atom transfer radical polymerization (ATRP, respectively. The formation of block copolymer was confirmed by gel permeation chromatography (GPC and NMR. Differential scanning calorimetry (DSC thermogram of block copolymers showed glass transition of PS block and melting/crystallization of P3HT block, suggesting a microphase separated structure, which was also confirmed by atomic force microscopy (AFM images and UV-vis absorption spectra. The annealing effect on the morphology of the composite films consisting of P3HT-b-PS and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM was investigated. Photovoltaic cells fabricated using P3HT-b-PS and PCBM were evaluated.

  14. Facile Synthesis of Mono-Dispersed Polystyrene (PS/Ag Composite Microspheres via Modified Chemical Reduction

    Directory of Open Access Journals (Sweden)

    Wen Zhu

    2013-12-01

    Full Text Available A modified method based on in situ chemical reduction was developed to prepare mono-dispersed polystyrene/silver (PS/Ag composite microspheres. In this approach; mono-dispersed PS microspheres were synthesized through dispersion polymerization using poly-vinylpyrrolidone (PVP as a dispersant at first. Then, poly-dopamine (PDA was fabricated to functionally modify the surfaces of PS microspheres. With the addition of [Ag(NH32]+ to the PS dispersion, [Ag(NH32]+ complex ions were absorbed and reduced to silver nanoparticles on the surfaces of PS-PDA microspheres to form PS/Ag composite microspheres. PVP acted both as a solvent of the metallic precursor and as a reducing agent. PDA also acted both as a chemical protocol to immobilize the silver nanoparticles at the PS surface and as a reducing agent. Therefore, no additional reducing agents were needed. The resulting composite microspheres were characterized by TEM, field emission scanning electron microscopy (FESEM, energy-dispersive X-ray spectroscopy (EDS, XRD, UV-Vis and surface-enhanced Raman spectroscopy (SERS. The results showed that Ag nanoparticles (NPs were homogeneously immobilized onto the PS microspheres’ surface in the presence of PDA and PVP. PS/Ag composite microspheres were well formed with a uniform and compact shell layer and were adjustable in terms of their optical property.

  15. Tailored synthesis of amine N-halamine copolymerized polystyrene with capability of killing bacteria.

    Science.gov (United States)

    Cai, Qian; Bao, Sarina; Zhao, Yue; Zhao, Tianyi; Xiao, Linghan; Gao, Ge; Chokto, Harnoode; Dong, Alideertu

    2015-04-15

    Novel amine N-halamine copolymerized polystyrene (ANHCPS) nanostructures were controllably fabricated as potent antibiotics by using the surfactant-free emulsion copolymerization for killing pathogenic bacteria. The morphology and size of the ANHCPS were well tailored by tuning reaction conditions such as monomer molar ratio, temperature, and copolymerization time. Effect of chlorination aging time on the oxidative chlorine content in the ANHCPS was established, and the oxidative chlorine content was determined by the modified iodometric/thiosulfate technique. Antibacterial behavior of the ANHCPS on bacterial strain was evaluated using Staphylococcus aureus and Escherichia coli as model pathogenic bacteria via the plate counting technique, inhibition zone study, and time-kill assay. Antimicrobial results illustrated that the ANHCPS possessed superior antibacterial capability of killing pathogenic bacteria. The destruction induced by the ANHCPS on bacterial surface structure was proven by using SEM technique. The effect of the oxidative chlorine content and morphology/size on the antimicrobial capability was constructed as well. This study provides us a novel approach for controllably synthesizing amine N-halamine polymers, and making them the potent candidates for killing bacteria or even the control of microorganism contamination. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. One-pot synthesis of iniferter-bound polystyrene core nanoparticles for the controlled grafting of multilayer shells

    Science.gov (United States)

    Marchyk, Nataliya; Maximilien, Jacqueline; Beyazit, Selim; Haupt, Karsten; Sum Bui, Bernadette Tse

    2014-02-01

    A novel approach using one-pot synthesis for the production of uniform, iniferter-bound polystyrene core nanoparticles of size 30-40 nm is described. Conventional oil-in-water emulsion polymerisation of styrene and divinylbenzene, combining a hybrid initiation system (thermal and UV), triggered sequentially, was employed to form the surface-bound thiocarbamate iniferters in situ. The iniferter cores were then used as seeds for re-initiating further polymerisation by UV irradiation to produce water-compatible core-shell nanoparticles. Grafting of various shell-types is demonstrated: linear polymers of poly(N-isopropylacrylamide) brushes, crosslinked polymers bearing different surface charges and molecularly imprinted polymers. The shell thickness was readily tuned by varying the monomers' concentration and polymerisation time. Our method is straightforward and in addition, gives access to the preparation of fluorescent seeds and the possibility of grafting nanosized multiple shells. The core-shell nanoparticles were fully characterised by dynamic light scattering, transmission electron microscopy, Fourier transform infrared spectroscopy and microelemental analysis.A novel approach using one-pot synthesis for the production of uniform, iniferter-bound polystyrene core nanoparticles of size 30-40 nm is described. Conventional oil-in-water emulsion polymerisation of styrene and divinylbenzene, combining a hybrid initiation system (thermal and UV), triggered sequentially, was employed to form the surface-bound thiocarbamate iniferters in situ. The iniferter cores were then used as seeds for re-initiating further polymerisation by UV irradiation to produce water-compatible core-shell nanoparticles. Grafting of various shell-types is demonstrated: linear polymers of poly(N-isopropylacrylamide) brushes, crosslinked polymers bearing different surface charges and molecularly imprinted polymers. The shell thickness was readily tuned by varying the monomers' concentration and

  17. Two-photon chemistry: Facile synthesis of naphthalene- and anthracene-labelled polystyrene by photolysis of aromatic esters

    OpenAIRE

    Holdcroft, Steven; Tang, Ben-Zhong; Guillet, James E.

    1991-01-01

    Photolysis of 9-anthrylmethyl 9-anthrylacetate and 1-naphthylmethyl 1-naphthylacetate in the presence of polystyrene yields polymers which are labelled with the fluorescent groups of anthrylmethyl and naphthylmethyl, respectively; this novel technique for the fluorescent labelling of polystyrene is believed to involve two-photon excitation.

  18. Synthesis and characterisation of simultaneous interpenetrating polymer networks (SIN formed by polystyrene and polyurethane obtained from castor oil and cassava starch polyol-suspensions

    Directory of Open Access Journals (Sweden)

    Juan Manuel Cabrera Anaya

    2011-01-01

    Full Text Available Castor oil was modified by transesterification with pentaerythritol and cassava starch was subsequently incorporated into this oil (oil modified by incorporating starch is called a polyol-suspension. Polyurethane/polystyrene SINs (simulta- neously produced IPNs were synthesised from them and styrene. Reactants used in the synthesis were MDI (methylene diphenyl diisocyanate as diisocyanate, DVB (divinylbenzene as crosslinking agent for polystyrene, dibutylamine as redox primer and benzoyl peroxide as styrene polymerisation primer. The variables considered in SIN synthesis were percentage weight ratio used in the modification (1.32%; 2.64% and 5.28% to increase polyol hydroxyl functionality, starch species incorporated into polyol (Brazilian, Venezuelan and commercial to vary the amount of amylopectin within the polyol-suspension, diisocyanate/hydroxyl NCO/OH (0.85 and 1 functional groups’ molar ratio and polyurethane/ polystyrene PU/PS weight ratio (70/30 and 80/20. A wide range of materials was obtained and characterised by tensile strength, hardness, chemical attack and Soxhlet extraction. The physical-mechanical properties of the materials produced with polyols (transesterified castor oil were improved when starch was incorporated into the polyol. Several tests indicated that 24 hours as curing time were not enough, because the SINs showed lower physical-mechanical properties than the homologous polyurethane elastomers did; thus, the curing time had to be increased to 48 hours.

  19. Synthesis and characterization of new chiral ketopinic acid-derived catalysts immobilized on polystyrene-bound imidazole

    Directory of Open Access Journals (Sweden)

    Hassan Yusuf

    2017-02-01

    Full Text Available Four new chiral ketopinic acid-derived catalysts were anchored on a polystyrene-bound imidazole via non-covalent bond. The resulting heterogeneous catalysts were successfully characterized using IR, SEM, and TGA analyses.

  20. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [Ministry of Education, Beijing University of Chemical Technology, Key Laboratory of Carbon Fiber and Functional Polymer (China)

    2015-01-15

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag{sup +} and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA){sub 2}]{sup +}) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO{sub 3} and Py, the introduction of [Ag(TEA){sub 2}]{sup +} ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA){sub 2}]{sup +} ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 10{sup 5} – 9×10{sup 5} cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract.

  1. Synthesis and properties of a photovoltaic cell based on polystyrene-functionalised Si nanowires filled into a poly(N-vinylcarbazole) matrix

    Energy Technology Data Exchange (ETDEWEB)

    Ben Dkhil, Sadok, E-mail: sadok.bendekhil@gmail.com [Laboratoire Physique des Materiaux, Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, Facultes des sciences de Bizerte, 7021 Jarzouna-Bizerte (Tunisia); Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Bourguiga, Ramzi [Laboratoire Physique des Materiaux, Structures et Proprietes Groupe Physique des Composants et Dispositifs Nanometriques, Facultes des sciences de Bizerte, 7021 Jarzouna-Bizerte (Tunisia); Beyou, Emmanuel, E-mail: beyou@univ-lyon1.fr [Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Davenas, Joel [Ingenierie des Materiaux Polymeres, CNRS UMR5223, Universite de Lyon, Universite Lyon1, 15 boulevard Latarget, F-69622 Villeurbanne (France); Cornu, David [Institut Europeen des Membranes, UMR CNRS 5635, Ecole Nationale superieure de Chimie, Universite de Montpellier, 1919 route de Mende, F34000 Montpellier (France)

    2012-10-15

    Grafting of polystyrene (PS) from silica coating of silicon nanowires (SiNWs) has improved the dispersion of SiNWs in poly(N-vinylcarbazole) (PVK) matrix to form a bulk heterojunction (BHJ) hybrid photovoltaic (HPV) cell. First, an alkoxyamine, based on N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (DEPN) was covalently attached onto SiNWs through free surface silanol groups. Then, polystyrene chains with controlled molecular weights and narrow polydispersities were grown from the alkoxyamine-functionalized SiNWs surface in the presence of a 'free' sacrificial styrylDEPN alkoxyamine. Both the initiator and the polystyrene chains were characterized by FTIR and {sup 13}C Solid-State NMR and quantified by TGA. The hybrid layer of SiNWs and PVK, results in cell performance improvement in respect to a reference cell based on PVK alone. A fill factor of 50% is achieved upon inclusion of PS grafted SiNWs. Highlights: Black-Right-Pointing-Pointer Grafting of well defined PS chains onto silicon nanowires. Black-Right-Pointing-Pointer Synthesis of PS@SiO{sub 2}@SiNWs core-shell nanostructures. Black-Right-Pointing-Pointer Homogeneous dispersion of PS-grafted-SiNWs in PVK matrix. Black-Right-Pointing-Pointer Good photovoltaic performances including a fill factor of 0.5.

  2. Polystyrene/magnetite nanocomposite synthesis and characterization: investigation of magnetic and electrical properties for using as microelectromechanical systems (MEMS

    Directory of Open Access Journals (Sweden)

    Omidi Mohammad Hassan

    2017-02-01

    Full Text Available In this work, a novel polystyrene/Fe3O4 nanocomposite prepared by in-situ method is presented. Magnetic Fe3O4 nanoparticles were encapsulated by polystyrene. The FT-IR spectra confirmed polystyrene/Fe3O4 nanocomposite preparation. The electrical properties of prepared nanocomposite were investigated by cyclic voltammetry (CV. The CV analysis showed good electrical conductivity of the synthesized nanocomposite. Magnetic properties of the nanocomposite were studied by vibrating sample magnetometer (VSM. The VSM analysis confirmed magnetic properties of the nanocomposite. The morphology and the size of the synthesized nanocomposite were investigated by field emission scanning electron microscope (FESEM. According to the VSM and CV results, such nanocomposite can be used in microelectromechanical systems.

  3. Nanostructured polystyrene-block-poly(4-vinyl pyridine)(pentadecylphenol) thin films as templates for polypyrrole synthesis

    NARCIS (Netherlands)

    Zoelen, Wendy van; Bondzic, Sasa; Fernández Landaluce, Tatiana; Brondijk, Johan; Loos, Katja; Schouten, Arend-Jan; Rudolf, Petra; Brinke, Gerrit ten

    2009-01-01

    Polypyrrole has been chemically synthesized on thin film nanostructures obtained from comb-shaped supramolecules of polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) hydrogen bonded with pentadecylphenol (PDP). PDP was washed from thin films of cylindrical and lamellar self-assembled

  4. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene; Sintese e caracterizacao de um aditivo tipo superplastificantes obtido a partir de copos plasticos de poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Carolina G.L.; Freire, Carolina B.; Tello, Cledola C. de O., E-mail: carolina_gabriela316@yahoo.com.br, E-mail: cbf@cdtn.br, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-BH), Belo Horizonte, MG (Brazil)

    2013-07-01

    This paper aims to describe the synthesis of an additive type superplasticizer from alternative material - plastic cups used of polystyrene - and characterize it physically and chemically in order to verify their efficiency and compare it with a commercial use superplasticizer. Following the search, the synthesized superplasticizer is used in mortars to assess their efficiency.

  5. Synthesis and characterization of polystyrene embolization particles doped with tantalum oxide nanoparticles for X-ray contrast.

    Science.gov (United States)

    Morrison, Rachel; Thompson, James; Bird, Luke; Hill, Mark A; Townley, Helen

    2015-08-01

    Radiopaque and fluorescent embolic particles have been synthesized and characterised to match the size of vasculature found in tumours to ensure effective occlusion of the vessels. A literature search showed that the majority of vessels surrounding a tumour were less than 50 µm and therefore polydispersed polystyrene particles with a peak size of 50 µm have been synthesised. The embolic particles contain 5-8 nm amorphous tantalum oxide nanoparticles which provide X-ray contrast. Embolic particles containing up to 9.4 wt% tantalum oxide were prepared and showed significant contrast compared to the undoped polystyrene particles. The X-ray contrast of the embolic particles was shown to be linear (R(2) = 0.9) with respect to the concentration of incorporated tantalum nanoparticles. A model was developed which showed that seventy-five 50 µm embolic particles containing 10% tantalum oxide could provide the same contrast as 5 cm of bone. Therefore, the synthesized particles would provide sufficient X-ray contrast to enable visualisation within a tumour.

  6. Synthesis of blue-photoluminescent graphene quantum dots/polystyrenic anion-exchange resin for Fe(III) detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenjun, E-mail: wjzhang@hebut.edu.cn; Gan, Jie

    2016-05-30

    Highlights: • GQD/PS-AER was prepared as a solid fluorescent sensor with millimeter size. • The GQD/PS-AER sensor could detect Fe{sup 3+} ions selectively. • The GQD/PS-AER sensor could be reusable. • This method is simple and economical. - Abstract: A novel solid fluorescent sensor with millimeter size, based on graphene quantum dots/polystyrenic anion-exchange resin (GQDs/PS-AER) was obtained for the detection of Fe{sup 3+}. The linear response range of Fe{sup 3+} was obtained from 1 μM to 7 μM and the detection limit was as low as 0.65 μM. In addition, the sensor could be regenerated by adding complexing agent EDTA and be separated by using simple filtration.

  7. Poly(butylene succinate-co-butylene adipate)/cellulose nanocrystal composites modified with phthalic anhydride.

    Science.gov (United States)

    Zhang, Xuzhen; Zhang, Yong

    2015-12-10

    As a kind of biomass nanofiller for polymers, cellulose nanocrystal (CNC) has good mechanical properties and reinforcing capability. To improve the compatibility of poly(butylene succinate-co-butylene adipate) (PBSA)/CNC composites, phthalic anhydride was used as a compatilizer during melt mixing, leading to the significant improvement of the mechanical properties and thermal stability of the composites, which is related to the better dispersion of CNC in the composites. The addition of phthalic anhydride could accelerate the crystallization of PBSA component as evidenced by the curves of isothermal crystallization of the composites, but had little effect on the crystalline polymorphs of PBSA component. The addition of phthalic anhydride could strongly improve the hydrophobicity of the composites. The good mechanical properties, fast crystallization and improved hydrophobicity of PBSA/CNC composites with phthalic anhydride are favor to their practical commercial utilization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Micelles of poly(styrene-b-2-vinylpyridine-b-ethylene oxide) with blended polystyrene core and their application to the synthesis of hollow silica nanospheres.

    Science.gov (United States)

    Liu, Dian; Sasidharan, Manickam; Nakashima, Kenichi

    2011-06-15

    Core-shell-corona (CSC) micelles of asymmetric triblock copolymer, poly(styrene-b-2-vinylpyridine-b-ethylene oxide) (PS-PVP-PEO), containing polystyrene homopolymer (homo-PS) in the core were successfully prepared in aqueous media. The influence of homo-PS contents over the formation of the micelles was investigated thoroughly by various techniques such as dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fluorescence spectroscopy. It was found that the size of the PS core of the micelle was increased by the addition of homo-PS as observed by DLS and TEM techniques. The SEM and TEM measurements confirm the spherical morphology of the micelles and enlargement of PS core over the addition of homo-PS. The increase in the PS core volume of the PS-PVP-PEO micelles is attributed to the insertion of homo-PS in the PS core. The micelles have also been demonstrated as facile soft templates for synthesis of hollow silica nanospheres. The average diameter of the spherical hollow particles could be tuned between 30.6 and 38.8 nm with cavity sizes ranging from 20.7 to 28.5 nm using tetramethoxysilane as silica precursors under mild acidic conditions. The facile synthesis of hollow silica using the CSC micelles with different homo-PS contents indicates that the hollow void size can be controlled within a range of several nanometers. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. Water Absorption Behavior of Polystyrene Particles Prepared by Emulsion Polymerization with Nonionic Emulsifiers and Innovative Easy Synthesis of Hollow Particles.

    Science.gov (United States)

    Okubo, Masayoshi; Kobayashi, Hiroshi; Huang, Chujuan; Miyanaga, Eri; Suzuki, Toyoko

    2017-04-11

    Submicrometer-sized raspberry-like polystyrene (PS) particles, which were prepared by emulsion polymerization with polyoxyethylene nonylphenyl ether nonionic emulsifier (Emulgen 910, HLB 12.2) and potassium persulfate initiator, contained 8.5 vol % (relative to the particle) of water and 5.5 wt % (relative to PS) of Emulgen 910 in the inside. The water absorption decreased the glass transition temperature of the PS particles dispersed in an aqueous medium. The wt % (relative to PS) of the incorporated Emulgen 910 increased with increasing initial Emulgen 910 concentration in the emulsion polymerization, but the wt % (relative to the total Emulgen 910 used) of the incorporated Emulgen 910 was constant at approximately 50% independent of the initial concentration. The vol % (relative to particle) of water increased to 46% by heat treatment at 90 °C for 24 h, which was based on further water absorption, and resulted in spherical hollow particles, where the amount of the incorporated Emulgen 910 remarkably decreased in a short treatment and then remained almost constant during the heat treatment. After another 24 h treatment, the percentage of nonhollow particles increased gradually, which was based on the escape of the water domain together with Emulgen 910 from the inside of the particles. On the other hand, spherical PS particles prepared by emulsifier-free emulsion polymerization did not contain water in the inside and were not changed to hollow ones by a similar heat treatment. From these results, an innovative easy method to synthesize hydrophobic hollow PS particles is proposed.

  10. Synthesis and Control of the Shell Thickness of Polyaniline and Polypyrrole Half Hollow Spheres Using the Polystyrene Cores

    Directory of Open Access Journals (Sweden)

    Su-Ryeon Yun

    2012-01-01

    Full Text Available Polyaniline (Pani and polypyrrole (Ppy half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.

  11. Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports

    Directory of Open Access Journals (Sweden)

    Kerstin Knepper

    2012-07-01

    Full Text Available The synthesis of diverse substituted indole structures on solid supports is described. The immobilization of nitrobenzoic acid onto Merrifield resin and the subsequent treatment with alkenyl Grignard reagents delivered indole carboxylates bound to solid supports. In contrast to results in the liquid phase, ortho,ortho-unsubstituted nitroarenes also delivered indole moieties in good yields. Subsequent palladium-catalyzed reactions (Suzuki, Heck, Sonogashira, Stille delivered, after cleavage, the desired molecules in moderate to good yields over four steps. The scope and limitations are presented.

  12. Structure-barrier property relationship of biodegradable poly(butylene succinate) and poly[(butylene succinate)-co-(butylene adipate)] nanocomposites: influence of the rigid amorphous fraction.

    Science.gov (United States)

    Charlon, S; Marais, S; Dargent, E; Soulestin, J; Sclavons, M; Follain, N

    2015-11-28

    Composites composed of polyesters, poly(butylene succinate) (PBS) or poly[(butylene succinate)-co-(butylene adipate)] (PBSA), and 5 wt% of montmorillonite (CNa) or organo-modified montmorillonite (C30B) were melt-processed and transformed into films by either compression-molding or extrusion-calendering. XRD, rheological measurements and TEM images clearly indicated that films containing CNa are microcomposites, while nanocomposites were observed for those containing C30B. Using Flash DSC, it was possible, for the first time, not only to measure the heat capacity step at the glass transition of these two materials in their amorphous state, but also to investigate whether the preparation technique influenced the Rigid Amorphous Fraction (RAF) in our PBS- and PBSA-based nanocomposites. In this work, we have successfully shown the correlation between the microstructure of the films and their barrier properties, and especially the role played by the RAF. Indeed, the lowest permeabilities to gases and to water were determined in the films containing the highest RAF in both PBS- and PBSA-based materials.

  13. Synthesis and self-assembly of Chitosan-g-Polystyrene copolymer: A new route for the preparation of heavy metal nanoparticles

    KAUST Repository

    Francis, Raju S.

    2015-01-01

    Amphiphilic graft copolymers made of a Chitosan (CS) backbone and three arm polystyrene (PS) grafts were prepared by "grafting onto" strategy using Toluene Diisocyanate. IR spectroscopy and SEC show the successful grafting process. SEM pictures of Chitosan-g-Polystyrene (CS-g-PS) indicate a spherulite like surface and exhibit properties that result from the disappearance of Chitosan crystallinity. The introduced polystyrene star grafts units improve hydrophobic properties considerably as confirmed by the very high solubility of (CS-g-PS) in organic solvents. The graft copolymer which self-assembles into polymeric micelles in organic media demonstrates much better adsorption of transition and inner transition metal ions than pure Chitosan whose amine groups are not necessarily available due to crystallinity.

  14. Substrate Effect on 2,3-Butylene Glycol Production by Rhizopus nigricans and Penicillium expansum1

    Science.gov (United States)

    Fields, M. L.; Richmond, Bonnie

    1967-01-01

    Rhizopus nigricans and Penicillium expansum produced 2,3-butylene glycol which accumulated in natural and artificial media with time. Mycelial mats of P. expansum decreased the quantity of a diacetyl substrate and converted part of this substrate into acetylmethylcarbinol (AMC) and 2,3-butylene glycol. Mycelial mats of P. expansum also decreased AMC substrate with the formation of 2,3-butylene glycol. 2,3-Butylene glycol decreased slightly during incubation with the fungal mat. The formation of AMC was suppressed significantly by cysteine and ascorbic acid. PMID:6080717

  15. Substrate effect on 2,3-butylene glycol production by Rhizopus nigricans and Penicillium expansum.

    Science.gov (United States)

    Fields, M L; Richmond, B

    1967-11-01

    Rhizopus nigricans and Penicillium expansum produced 2,3-butylene glycol which accumulated in natural and artificial media with time. Mycelial mats of P. expansum decreased the quantity of a diacetyl substrate and converted part of this substrate into acetylmethylcarbinol (AMC) and 2,3-butylene glycol. Mycelial mats of P. expansum also decreased AMC substrate with the formation of 2,3-butylene glycol. 2,3-Butylene glycol decreased slightly during incubation with the fungal mat. The formation of AMC was suppressed significantly by cysteine and ascorbic acid.

  16. Synthesis of polyacrylonitrile-grafted cross-linked N-chlorosulfonamidated polystyrene via surface-initiated ARGET ATRP, and use of the resin in mercury removal after modification

    Energy Technology Data Exchange (ETDEWEB)

    Zong Guangxi [School of Chemistry and Materials Science, Ludong University, Hongqi Road 186, Yantai 264025 (China); Chen Hou, E-mail: sdchenhou@hotmail.com [School of Chemistry and Materials Science, Ludong University, Hongqi Road 186, Yantai 264025 (China); Qu Rongjun; Wang Chunhua; Ji Naiyi [School of Chemistry and Materials Science, Ludong University, Hongqi Road 186, Yantai 264025 (China)

    2011-02-15

    A novel method of surface modification was developed via iron (III)-mediated atom transfer radical polymerization, with activators regenerated by electron transfer (ARGET ATRP) on the surfaces of polystyrene resin-supported N-chlorosulfonamide groups. The well-defined polyacrylonitrile (PAN) was grafted onto the surfaces of the polystyrene (PS). The graft reaction exhibited first-order kinetics with respect to the polymerization time in the low-monomer-conversion stage. The cyano group of PAN-g-PS was modified by NH{sub 2}OH.HCl to yield amidoxime (AO) groups. The AO groups had been demonstrated to be an efficient Hg-specific sorbent, which can remove Hg{sup 2+} from solutions. No interference arose from common metal ions, such as Pd{sup 2+}, Ag{sup +}, and Cu{sup 2+}. Three adsorption-desorption cycles demonstrated that this resin is suitable for reuse without any considerable change in adsorption capacity.

  17. Polymer supported gold nanoparticles: Synthesis and characterization of functionalized polystyrene-supported gold nanoparticles and their application in catalytic oxidation of alcohols in water

    Science.gov (United States)

    Kaboudin, Babak; Khanmohammadi, Hamid; Kazemi, Foad

    2017-12-01

    Sulfonated polystyrene microsphere were functionalized using ethylene diamine to introduce amine groups to the polymer chains. The amine functionalized polymers were used as a support for gold nanoparticles. A thorough structural characterization has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, EDS, CHN and atomic absorption spectroscopy. The polymer supported gold nanoparticles was found to be an efficient catalyst for the oxidation of alcohols in water.

  18. Carbohydrate microarrays in 96-well polystyrene microtiter plates.

    Science.gov (United States)

    Ebran, Jean-Philippe; Dendane, Nabil; Melnyk, Oleg

    2012-01-01

    A method for the preparation of carbohydrate microarrays inside 96-well polystyrene microtiter plates is described. The key step in this strategy represents the synthesis of carbohydrate-dextran conjugates by copper (I)-catalyzed [3 + 2] cycloaddition between alkyne carbohydrate derivative and a specially designed azido dextran polymer. The conjugates adsorb efficiently on polystyrene surface and can be printed inside 96-well plates using a non-contact piezoelectric microarrayer. Model interactions with a selection of lectins (concanavalin A, wheat germ agglutinin, Erythrina Cristagalli) display the efficiency of the immobilization method, its reproducibility and the specificity of biomolecular interactions occurring at the polystyrene-water interface.

  19. Synthesis and luminescence properties of polymeric complexes of Cu(II), Zn(II) and Al(III) with 8-hydroxyquinoline side group-containing polystyrene

    Science.gov (United States)

    Gao, Baojiao; Wei, Xiaopeng; Zhang, Yanyan

    2013-01-01

    Three kinds of metalloquinolate-containing polystyrene were prepared via a polymer reaction and a coordination reaction. 5-Chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction of 8-hydroxyquinoline (HQ) with 1,4-bichloromethoxy-butane as chloromethylation reagent. A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between polystyrene (PS) and CHQ in the presence of Lewis catalyst, and HQ was bonded onto the side chains of PS, obtaining 8-hydroxyquinoline-functionalized Polystyrene, HQ-PS. And then, by using one-pot method with two-stage procedures, the coordination reaction of HQ-PS and small molecule HQ with metal ions including Al(III), Zn(II) and Cu(II) ions, was allowed to be carried out, and three polymeric metalloquinolates, AlQ3-PS, ZnQ2-PS and CuQ2-PS, were successfully prepared, respectively. In the chemical structures of these polymeric metalloquinolates, metalloquinolates were chemically attached onto the side chains of PS. HQ-PS and three polymeric metalloquinolates were fully characterized by FTIR, 1H NMR and TGA. The luminescence properties of the three polymeric metalloquinolates were mainly investigated by UV/Vis absorption spectra and fluorescence emission spectra in solutions and in solid film states. When excited by the ray at about 365 nm, the three polymeric metalloquinolates have blue-green luminescence, and the main emission peaks in the DMF solutions are located at 490, 482 and 502 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. As compared with their emissions in solutions, the emissions in solid film states are red-shifted to some extent, and the main emission peaks are located at 500, 488 and 510 nm for AlQ3-PS, ZnQ2-PS and CuQ2-PS, respectively. Besides, these polymeric metalloquinolates have higher thermal stability than PS as polymeric skeleton.

  20. Synthesis and characterization of sulfonate polystyrene-lignosulfonate-alumina (SPS-LS-Al{sub 2}O{sub 3}) polyblends as electrolyte membranes for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Gonggo, Siang Tandi, E-mail: standigonggo@yahoo.com [Chemistry Research Groups, Faculty of Teacher Training and Educational Sciences, Tadulako University (Indonesia)

    2015-09-30

    The new type of electrolyte membrane materials has been prepared by blend sulfonated polystyrene (SPS), lignosulfonate (LS), and alumina (SPS-LS-Al{sub 2}O{sub 3}) by casting polymer solution. The resulting polymer electrolyte membranes were then characterized by functional groups analysis, mechanical properties, water uptake, ion exchange capacity, and proton conductivity. SPS-LS-Al{sub 2}O{sub 3} membranes with alumina composition various have been proven qualitatively by analysis of functional groups. Increasing the Al{sub 2}O{sub 3} ratio resulted in higher ion exchange capacity (IEC), mechanical strength and proton conductivity, but water uptake decreased. The SPS-LS-Al{sub 2}O{sub 3} blend showed higher proton conductivity than Nafion 117.

  1. Effect of organo-modified montmorillonite on poly(butylene succinate/poly(butylene adipate-co-terephthalate nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available The composite material based on poly(butylene succinate (PBS, poly(butylene adipate-co-terephthalate (PBAT and organo-modified montmorillonite (OMMT were prepared by melt blending technique and characterized. Sodium montmorillonite (Na-MMT was successfully modified by octadecylammonium (ODA and dimethyldioctadecylammonium (DDOA salts to become OMMT through cation exchange technique which is shown by the increase of basal spacing of clay by XRD. The addition of the OMMT to the PBS/PBAT blends produced nanocomposites which is proved by XRD and TEM. Tensile tests showed increase in tensile strength and modulus which is attributed to the existence of strong interactions between PBS/PBAT and clay, particularly with OMMT. Highest tensile strength of nanocomposite was observed at 1 wt% of OMMT incorporated. TGA study showed that the thermal stability of the blend increased after the addition of clays. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes homogeneous and smoother with presence of OMMT.

  2. Facile synthesis of thick films of poly(methyl methacrylate), poly(styrene), and poly(vinyl pyridine) from Au surfaces.

    Science.gov (United States)

    Saha, Sampa; Bruening, Merlin L; Baker, Gregory L

    2011-08-01

    Atom transfer radical polymerization (ATRP) is commonly used to grow polymer brushes from Au surfaces, but the resulting film thicknesses are usually significantly less than with ATRP from SiO(2) substrates. On Au, growth of poly(methyl methacrylate) (PMMA) blocks from poly(tert-butyl acrylate) brushes occurs more rapidly than growth of PMMA from initiator monolayers, suggesting that the disparity between growth rates from Au and SiO(2) stems from the Au surface. Radical quenching by electron transfer from Au is probably not the termination mechanism because polymerization from thin, cross-linked initiators gives film thicknesses that are essentially the same as the thicknesses of films grown from SiO(2) under the same polymerization conditions. However, this result is consistent with termination through desorption of thiols from noncross-linked films, and reaction of these thiols with growing polymer chains. The enhanced stability of cross-linked initiators allows ATRP at temperatures up to ∼100 °C and enables the growth of thick films of PMMA (350 nm), polystyrene (120 nm) and poly(vinyl pyridine) (200 nm) from Au surfaces in 1 h. At temperatures >100 °C, the polymer brush layers delaminate as large area films.

  3. A study on the synthesis of polystyrene-silica nanocomposite particles by soap-free emulsion polymerization using cationic initiator in company with colloidal silica sol solution.

    Science.gov (United States)

    Lee, Sangkug; An, You Sun; Kim, Jae Gu; Park, In; Chun, Hyunaee; Kim, Gyungsoo; Choi, Kyung Ho

    2009-12-01

    Nano-sized polystyrene (PS)-silica nanocomposite particles have been prepared by soap-free emulsion polymerization using a cationic initiator, 2,2'-azobis(isobutyramidine) hydrochloride (AIBA) with a colloidal silica (Ludox SM30, 7 nm diameter). The cationic initiator leads to the formation of the PS-silica nanocomposite particles by electrostatic interaction with negatively charged silica particles. Morphology, particle size distribution, reactivity and silica content of the particles were monitored on different reaction conditions such as pH, the addition time of silica sol and the amount of the silica sol. It is found that the nucleation of styrene monomer depends on the pH of water medium, the addition time of silica, the presence of silica in polymerization system. The reaction whose styrene monomer didn't react in water medium with pH 10 was progressed in the presence of silica sol to give nanocomposite particles. In the condition of constant pH 10 in the polymerization system, the increase of the amount of silica gave little influence to the changes in the particle size and particle size distribution of nanocomposite particles. The changes in the pH of medium gave much influence on the particle size and particle size distribution due to the changes in ionic interaction of silica and initiator. The silica content absorbed on the nanocomposite particles decreases with decreasing the pH values in the polymerization media.

  4. Synthesis of poly (methyl methacrylate)-b-polystyrene with high molecular weight by DPE seeded emulsion polymerization and its application in proton exchange membrane.

    Science.gov (United States)

    Wang, Wenwen; Zhang, Hepeng; Geng, Wangchang; Gu, Junwei; Zhou, Yanyang; Zhang, Junping; Zhang, Qiuyu

    2013-09-15

    In this article, we present poly (methyl methacrylate)-b-polystyrene (PMMA-b-PS) with different block ratios and high molecular weight, which was synthesized by environmentally friendly seeded emulsion polymerization with 1,1-diphenylethylene (DPE) as a chain transfer agent. Polymerization kinetics in the first and second stage was investigated. Stable latex and homogeneous latex particles were obtained with the characterization of laser light scattering (LLS) and transmission electron microscopy (TEM). SEC and (1)H NMR revealed the successful preparation of block copolymers with high molecular weight and two different block ratios. The morphology of microphase separation of block copolymer thin films was investigated by AFM, and long-range order lamellar morphology was observed after vapor-annealing. The block copolymer with block ratio of almost 1:1 and higher molecular weight than that of previous PMMA-b-PS was sulfonated with acetyl sulfate, and the sulfonation was confirmed by FTIR, (1)H NMR, and TGA. Then, the sulfonated PMMA-b-PS was casted as membranes. The electrochemical impedance spectroscopy displayed that membranes possessed favorable proton conductivity and fine dimensional stability, and they could be candidates as proton exchange membranes. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. A simple solvent blending coupled sonication technique for synthesis of polystyrene (PS/multi-walled carbon nanotube (MWCNT nanocomposites: Effect of modified MWCNT content

    Directory of Open Access Journals (Sweden)

    Payel Sen

    2016-09-01

    Full Text Available The influence of carboxylic acid functionalized multi-walled carbon nanotubes (cMWCNTs content on the properties of polystyrene (PS nanocomposite (NC films was investigated. The NC films were produced by a simple sonication assisted solvent blending technique. The interaction between the matrix (PS and well dispersed filler (cMWCNT was evaluated by different techniques involving Fourier transform infrared spectroscopy, Raman spectroscopy and X-Ray diffraction. Morphological images of the NCs were collected from Transmission electron microscopy. The thermal characteristics of the PS were found to be improved by the incorporation of the cMWCNTs, which was evident from the Thermogravimetric analysis (TGA data. The thermal degradation activation energy evaluated by Coats-Redfern method and integral procedural decomposition temperature determined by Doyle's method supported the thermal stability proposed by TGA of the NCs. The reaction mechanism of thermal degradation of neat PS and respective NCs was successfully predicted using Criado method. The rheological properties and hardness were found to be upgraded by the inclusion of nanotubes to the PS matrix.

  6. Multifunctional nanobiocomposite of Poly[(butylene succinate)-co-adipate] and clay

    CSIR Research Space (South Africa)

    Al-Thabaiti, SA

    2015-03-01

    Full Text Available The processing and characterization of multifunctional nanobiocomposite of biodegradable poly[(butylene succinate)-co-adipate] (PBSA) and organically modified synthetic fluorine mica (OSFM) are reported. The nanobiocomposite of PBSA with OSFM...

  7. EFFECT OF INCORPORATING EXPANDED POLYSTYRENE ...

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. Incorporating expanded polystyrene granules in concrete matrix can produce lightweight polystyrene aggregate concrete of various densities. Workability which is an important property of concrete, affects the rate of placement and the degree of compaction of concrete. Inadequate compaction.

  8. Elongational dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Skov, Anne Ladegaard; Nielsen, Jens Kromann

    2009-01-01

    The startup of uni-axial elongational flow followed by stress relaxation and reversed bi-axial flow has been measured for a branched polystyrene melt with narrow molar mass distribution using the filament stretching rheometer. The branched polystyrene melt was a multiarm A(q)-C-C-A(q) pom......-pom polystyrene with an estimated average number of arms of q=2.5. The molar mass of each arm is about 28 kg/mole with an overall molar mass of M-w=280 kg/mole. An integral molecular stress function constitutive formulation within the "interchain pressure" concept agrees reasonably well with the experiments....

  9. Removal of propylene and butylene as individual compounds with compost and wood chip biofilters.

    Science.gov (United States)

    Rani, Madhu; Sattler, Melanie L

    2011-05-01

    Propylene and butylene are highly reactive volatile organic compounds (HRVOCs) in terms of ground-level ozone formation. This study examined the effectiveness of biofiltration in removing propylene and butylene as separate compounds. Specific objectives were (1) to measure maximum removal efficiencies for propylene and butylene and the corresponding microbial acclimation times, which will be useful in the design of future biofilters for removal of these compounds; (2) to compare removal efficiencies of propylene and butylene for different ratios of compost/hard wood-chip media; and (3) to identify the microorganisms responsible for propylene and butylene degradation. Two laboratory-scale polyvinyl chloride biofilter columns were filled with 28 in. of biofilter media (compost/wood-chip mixtures of 80:20 and 50:50 ratios). Close to 100% removal efficiency was obtained for propylene for inlet concentrations ranging from 2.9 x 10(4) to 6.3 x 10(4) parts per million (ppm) (232-602 g/m3-hr) and for butylene for inlet concentrations ranging from 91 to 643 ppm (1.7-13.6 g/m3-hr). The microbial acclimation period to attain 100% removal efficiency was 12-13 weeks for both compounds. The lack of similar microbial species in the fresh and used media likely accounts for the long acclimation time required. Both ratios of compost/wood chips (80:20 and 50:50) gave similar results. During the testing, media pH increased slightly from 7.1 to 7.5-7.7. None of the species in the used media that treated butylene were the same as those in the used media that treated propylene, indicating that different microbes are adept at degrading the two compounds.

  10. Crystallization phenomena of isotactic polystyrene

    NARCIS (Netherlands)

    Lemstra, Peter Jan

    1975-01-01

    In this thesis the crystallization behavior of isotactic polystyrene has been described. The kinetics of the crystallization process and the crystalline structure were studied both for crystallization in the bulk and from dilute solutions. ... Zie Summary

  11. Síntese de poliestireno sulfonado para aplicações no tratamento de água produzido a partir de copos e bandejas descartadas de poliestireno Synthesis of poly(styrene sulfonate from discarded polystyrene cups and expanded trays for application on water treatment

    Directory of Open Access Journals (Sweden)

    Guimes Rodrigues Filho

    2008-01-01

    Full Text Available In the present paper, the use of poly(styrene sulfonate (PSS, produced from discarded polystyrene materials through heterogeneous and homogeneous processes, was investigated. The use of PSS for water treatment, using a kaolin suspension as wastewater model, reduced water turbidity for all the employed materials when compared to the blank analysis, without PSS. The most efficient polyelectrolyte was PSS cups obtained by homogeneous route. The same behavior was observed for real system. The homogeneous PSS cups showed a balance between a moderate molecular weight and high anionic character that improved flocks formation and water removal turbidity.

  12. Incorporation of Nanohybrid Films of Silica into Recycled Polystyrene Matrix

    Directory of Open Access Journals (Sweden)

    Genoveva Hernández-Padrón

    2015-01-01

    Full Text Available An alternative for the reutilization of polystyrene waste containers consisting in creating a hybrid material made of SiO2 nanoparticles embedded in a matrix of recycled polystyrene (PSR has been developed. Recycled polystyrene functionalized (PSRF was used to influence the morphological and antifog properties by the sol-gel synthesis of nanohybrid silica. To this end, silica nanoparticles were produced from alkoxide precursors in the presence of recycled polystyrene. The functionalization of this polymeric matrix was with the purpose of uniting in situ carboxyl and silanol groups during the sol-gel process. In this way, opaque or transparent solid substrates can be obtained, with each of these endowed with optical conditions that depend on the amount of reactants employed to prepare each nanohybrid specimen. The nanohybrids were labelled as SiO2/PSR (HPSR and SiO2/PSRF (HPSRF and their properties were then compared to those of commercial polystyrene (PS. All the prepared samples were used for coating glass substrates. The hydrophobicity of the resultant coatings was determined through contact angle measurement. The nanohybrid materials were characterized by FT-IR and 1H-NMR techniques. Additionally, TGA and SEM were employed to determine their thermal and textural properties.

  13. Preparation and properties of polystyrene encapsulated paraffin wax as possible phase change material in a polypropylene matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mochane, M.J. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa); Luyt, A.S., E-mail: LuytAS@qwa.ufs.ac.za [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa)

    2012-09-20

    Highlights: Black-Right-Pointing-Pointer Polystyrene microcapsules containing about 30 wt% soft paraffin wax were successfully prepared. Black-Right-Pointing-Pointer The presence of microcapsules in polypropylene influenced the morphology and properties of the matrix. Black-Right-Pointing-Pointer The SEBS modifier had little influence on the interaction between polypropylene and microcapsules. - Abstract: The study deals with the preparation and characterization of polystyrene (PS) capsules containing Fischer-Tropsch paraffin wax (PS:wax) as phase change material (PCM) for thermal energy storage embedded in a polypropylene (PP) matrix. Blends of PP/PS:wax were prepared without and with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) as a modifier. The influence of PS:wax microcapsules on the morphology, as well as thermal and mechanical properties of the PP was investigated. The scanning electron microscopy (SEM) images of the microencapsulated PCM show that the capsules were grouped in irregular spherical agglomerates of size 16-24 {mu}m. However, after melt-blending with PP smaller, perfectly spherical microcapsules were well dispersed in the PP matrix. There was fairly good interaction between the microcapsules and the matrix, even in the absence of SEBS modification. The FTIR spectrum of the microcapsules is almost exactly the same as that of polystyrene, which indicates that the microcapsules were mostly intact and that the FTIR only detected the polystyrene shell. The amount of wax in the PS:wax microcapsules was determined as 20-30% by weight. An increase in PS:wax content resulted in a decrease in the melting peak temperatures of PP. The thermal stability of the blends decreased with an increase in PS:wax microcapsules content as a consequence of the lower thermal stability of both the wax and PS. There was a drop in storage modulus with increasing PS:wax microcapsules content.

  14. Preparation of biodegradable porous poly(butylene succinate microspheres

    Directory of Open Access Journals (Sweden)

    Pepić Dragana

    2008-01-01

    Full Text Available The aim of this study was to determine the optimal conditions for the fabrication of porous microspheres based on poly(butylene succinate, PBS. The biodegradable non-porous PBS microspheres were prepared by the oil-in-water (o/w emulsion solvent evaporation method using poly(vinyl alcohol, PVA, as the surfactant. Fabrication conditions, such as stirring rate, organic/aqueous ratio, PBS concentration and surfactant (PVA concentration, which have an important influence on both the particle size and the morphology of the microspheres, were varied. Scanning electron microscopy, SEM, observations confirmed the size, size distribution and surface morphology of the microspheres. The optimal conditions for the preparation of the non-porous microspheres were found to be: concentration the PBS solution, 10 mass%; PVA concentration, 1 mass%; the organic/ aqueous ratio CHCl3/H2O = 1/20 and stirring rate 800 rpm. Porous PBS microspheres were fabricated under the optimal conditions using various amounts of hexane and poly(ethylene oxide, PEO, as porogens. The influence of the amount of porogen on the pore size and the particle size was investigated using SEM and the apparent density. The microspheres exhibited various porosities and the pore sizes. The average particle size of the microspheres with PEO as the porogen was from 100 to 122μm and that of the microspheres with hexane as the porogen was from 87 to 97μm. The apparent density of the porous microspheres with PEO as the porogen, from 0.16 to 0.23 g/cm3, was much smaller than the non-porous microspheres, 0.40 g/cm3. In the in vitro degradation experiments, the porous microspheres were incubated in phosphate buffer solution (pH 7 at 37°C. After incubating for one month, the microspheres showed significant extent of the hydrolytic degradation of the porous PBS microspheres.

  15. STUDY OF THE MAGNETIC PROPERTIES OF POROUS POLYSTYRENE NANOPARTICLES LOADED WITH MAGNETITE

    OpenAIRE

    Puca, M.; Dpto. Académico de Fisicoquímica, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Tacuri, E.; Facultad de Química e Ingeniería Química Universidad Nacional Mayor de San Marcos Lima, Perú; Hurtado, M.; Facultad de Química e Ing. Química Universidad Nacional Mayor de San Marcos Lima, Perú; Guerrero, M.; Dpto. de Química Orgánica, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Figueroa, A.; Dpto. de Fisicoquímica, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Rojas, N.; Dpto. de Fisicoquímica, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; Cjuno, J.; Dpto. de Fisicoquímica, FQIQ Universidad Nacional Mayor de San Marcos Lima, Perú; García, S.; Centro de Enseñanza Técnica Industrial-CETI.; Lopez, R. G.; Dpto. Procesos de Polimerización. Centro de Investigación en Química Aplicada-CIQA. Universidad Nacional Mayor de San Marcos Lima, Perú

    2014-01-01

    In this work the synthesis of magnetite nanoparticles by coprecipitación in inverse microemulsion, which were introduced inside the pores of the polystyrene nanoparticles is reported. The nanoparticles of porous polystyrene were synthesized by heterogeneous polymerization in semicontinuo, which were employed like cover polymeric due to their biocompatibility and biostability. Through the analysis by X-ray diffraction was verified the structure of the magnetite, and estimated its average diame...

  16. Secondary Crystallization of Isotactic Polystyrene

    NARCIS (Netherlands)

    LEMSTRA, PJ; SCHOUTEN, AJ; CHALLA, G

    1974-01-01

    When isotactic polystyrene (i-PS) is crystallized from the melt or from the glassy state at rather large supercooling an additional melting peak appears on the curve during scanning in a differential calorimeter. The overall rate of crystallization deduced from the total peak areas as a function of

  17. Synthesis and evaluation of polystyrene-polybutadiene-polystyrene-dodecafluoroheptyl methacrylate/polystyrene-polybutadiene-polystyrene hybrid antifouling coating.

    Science.gov (United States)

    Li, Jiang; Wang, Guoqing; Ding, Chunhua; Jiang, Hong; Wang, Peiqing

    2014-11-15

    Copolymers SBS-DFHMA and mesoporous silica SBA-15 were respectively synthesized and SBS-DFHMA were mixed with SBA-15 to prepared hybrid antifouling coatings by a spin-coater. By measuring the surface water contact angle and the attachment of Pseudomonas fluorescens, Chlorella and Diatoms, the antifouling properties of coatings were evaluated. The results shown that the surface of hybrid coatings, the water contact angle arrived 120°, were more hydrophobic than the SBS-DFHMA coatings. In terms of resistance of adhesion, low surface energy coatings of SBS-DFHMA could effectively weaken the adhesion behavior of P.fluorescens and Diatoms, but the role to Chlorella was not obvious. When 0.01 g/ml SBA-15 was added, the adhesion of three marine microorganisms all had a very significant decrease to the hybrid coatings. These indicated that the fluorinated low surface energy antifouling coatings had limitation on resisting Chlorella attaching, and the addition of SBA-15 not only enhanced the ability of resistance to adhesion but also widen the applicability to more fouling and narrowed its limitations. This surprising effect was due to micro-nano convex structure of the coatings surface caused by hybrid. Copyright © 2014. Published by Elsevier Inc.

  18. Viscoelastic and electrical properties of carbon nanotubes filled poly(butylene succinate)

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2014-03-01

    Full Text Available The carbon nanotubes (CNTs)-containing composites of poly(butylene succinate) (PBS) were prepared by melt-blending in a batch mixer with three concentrations by weight of CNTs: 1, 2 and 3 %. State of dispersion-distribution of the CNTs in the PBS...

  19. Incorporation of Isosorbide into Poly(butylene terephthalate) via Solid-State Polymerization

    NARCIS (Netherlands)

    Sablong, R.J.; Duchateau, R.; Konings, C.E.; Wit, de G.; Es, van D.S.; Koelewijn, R.; Haveren, van J.

    2008-01-01

    The biomass-based monomer isosorbide was incorporated into poly(butylene terephthalate) (PBT) by solid-state polymerization (SSP) using the macrodiol monomer BTITB-(OH)2, which consists of isosorbide (I), terephthalic acid (T), and 1,4-butandiol (B) residues. This macromonomer can be synthesized by

  20. Crystallization of poly(ethyleneterephthalate) and poly(butylene terephthalate) modified by diamides

    NARCIS (Netherlands)

    Bouma, K.; Gaymans, R.J.

    2001-01-01

    Poly(ethylene terephthalate) (PET) and poly (butylene terephthalate) have been modified by diamide units (0.1-1 mol%) in an extrusion process and the crystallization behavior studied. The diamides used were: for PET, T2T-dimethyl (N, N-bis(p-carbomethoxybenzoyl)ethanediamine) and for PBT,

  1. Electrospun Nanoporous Poly(butylenes succinate-co-bytylene terephthalate Nonwoven Mats

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2011-01-01

    Full Text Available A traditional Chinese drug “Yunnan Baiyao” is used as an additive in poly(butylenes succinate-co-bytylene terephthalate (PBST solution, which is a kind of biodegradable aliphatic-aromatic copolyesters, to produce microspheres with nanoporosity by electrospinning; the tunable size of nanoporosity can be controlled by changing the voltage applied in the electrospinning process.

  2. Viscoelastic properties of poly(butylene succinate)-co-adipate) nanocomposites

    CSIR Research Space (South Africa)

    Al-Thabaiti, SA

    2015-03-01

    Full Text Available This article reports the viscoelastic properties of poly[(butylene succinate)-co-adipate] (PBSA) nanocomposites. The nanocomposites of PBSA with various loadings of organically modified clay were prepared by melt-mixing in a batch-mixer. The solid...

  3. Gas-permeation properties of poly(ethylene oxide) poly(butylene terephthalate block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    This paper reports the gas-permeation properties of poly(ethylene oxide) (PEO) poly(butylene terephthalate) (PBT) segmented multiblock copolymers. These block copolymers allow a precise structural modification by the amount of PBT and the PEO segment length, enabling a systematic study of the

  4. Study of the mechanical behavior of thermo reversible gels of PS-b-poly(ethylene/butylene)-b-PS triblock copolymers in a selective solvent for the middle block of the copolymer; Estudio del comportamiento mecanico de geles fisicos termoreversibles obtenidos a partir de copolimeros tribloques de PS-b-poli(etileno/butileno)-PS en un disolvente selectivo del bloque central

    Energy Technology Data Exchange (ETDEWEB)

    Hernaez, E.; Inchausti, I.; Quintana, J. R.; Katime, I.

    2001-07-01

    The thermo reversible gelation of three triblock copolymers polystyrene-b-poly(ethylene/butylene)-b-polystyrene, with different molar mass and a similar chemical composition, in n-octane was studied. The solvent is selective for the middle poly(ethylene/butylene) block of the copolymers. the influence of the molar mass of the three copolymers on the gelation and on the mechanical properties of the gels was analysed. The sol-gel transition temperatures. T{sub g}el have been determined and they increase with the copolymer concentration and the copolymer molar mass. On the other land, the mechanical properties of the different gels were examined through oscillatory shear and compressive stress relaxation measurements. The concentration dependence of the elastic storage modules, G' for the three copolymer studied fit a sole straight line in a double-logarithmic scale and its slope (2.22) is close to that expected for systems in good solvents (2.25). As the temperature is near to the sol-gel transition temperate, the elastic modulus are smaller and the relaxation rates are higher. (Author) 12 refs.

  5. Surface Self-Assembly and Properties of Monolayers Formed by Reverse Poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) Triblock Copolymers with Lengthy Hydrophilic Blocks

    DEFF Research Database (Denmark)

    Villar-Alvarez, Eva; Freire, Adriana Cambón; Blanco, Mateo

    2017-01-01

    The surface behavior and properties of several reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) block copolymers, BO8EO90BO8, BO12EO227BO12, BO14EO378BO14, BO20EO411BO20, and BO21EO385BO21 at the air/water interface have been analyzed by drop tensiometry, Langmuir film balan...

  6. Controlling the biodegradability of poly(butylene succinate-co-butylene adipate) (PBSA) by solvents used in the dried-gel process

    Science.gov (United States)

    Yamazaki, Hana; Kamitabira, Saya; Maeda, Tomoki; Hotta, Atsushi

    Considering an environmentally friendly material, poly(butylene succinate-co-butylene adipate)(PBSA) is one of the attractive biodegradable plastics that can be eventually degraded into H2O and CO2 by neighboring water molecules and microorganisms after the disposal. In order to expand the application of PBSA, the precise control of the biodegradability of PBSA is necessary. In this study, the dried-gel process was introduced to control the biodegradability of PBSA. The dried PBSA gels were prepared by using three different solvents (toluene, cyclohexanone, and o-dichlorobenzene). The scanning electron microscopy (SEM) micrographs revealed that the PBSA prepared by toluene had smaller spherocrystals than the other PBSA dried-gels prepared by cyclohexanone or o-dichlorobenzene. The biodegradability testing by immersing the three types of PBSA in NaOH aq. showed that the percentage of the weight loss of the PBSA produced by toluene was the highest. The results indicated that the microstructures of PBSA could be controlled by changing solvents during the gel preparations, and that the biodegradability of PBSA could therefore be efficiently modified by changing solvents. This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 15H02298 to A.H.) and a Grant-in-Aid for Research Activity Start-up (No.15H06586 to T.M.) from JSPS: KAKENHI\\x9D.

  7. Reactive processing of maleic anhydride-grafted poly(butylene succinate and the compatibilizing effect on poly(butylene succinate nanocomposites

    Directory of Open Access Journals (Sweden)

    Z. A. Mohd Ishak

    2013-04-01

    Full Text Available In this study, maleic anhydride-grafted poly(butylene succinate (PBS-g-MA was synthesized via reactive meltgrafting process using different initiator contents. The grafting efficiency was increased with the initiator content, manifested by the higher degree of grafting in PBS-g-MA. The grafting reaction was confirmed through Fourier transform infrared (FTIR spectroscopy and nuclear magnetic resonance (NMR spectroscopy. Then, PBS-g-MA was incorporated into organo-montmorillonite (OMMT filled poly(butylene succinate (PBS nanocomposites as compatibilizer. Mechanical properties of PBS nanocomposites were enhanced after compatibilized with PBS-g-MA, due to the better dispersion of OMMT in PBS matrix and the improved filler-matrix interfacial interactions. This was verifiable through X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM. Differential scanning calorimetry (DSC showed that the degree of crystallinity and melting temperature increased after addition of PBS-g-MA. However, the presence of PBS-g-MA did not favor the thermal stability of the nanocomposites, as reported in the thermogravimetry (TGA.

  8. Polystyrene Based Silver Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Shiva Agarwal

    2002-06-01

    Full Text Available Silver(I selective sensors have been fabricated from polystyrene matrix membranes containing macrocycle, Me6(14 diene.2HClO4 as ionophore. Best performance was exhibited by the membrane having a composition macrocycle : Polystyrene in the ratio 15:1. This membrane worked well over a wide concentration range 5.0×10-6–1.0×10-1M of Ag+ with a near-Nernstian slope of 53.0 ± 1.0 mV per decade of Ag+ activity. The response time of the sensor is <15 s and the membrane can be used over a period of four months with good reproducibility. The proposed electrode works well in a wide pH range 2.5-9.0 and demonstrates good discriminating power over a number of mono-, di-, and trivalent cations. The sensor has also been used as an indicator electrode in the potentiometric titration of silver(II ions against NaCl solution. The sensor can also be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of Ag+ in solution having up to 25% (v/v nonaqueous fraction.

  9. Technical Note: Effect of Incorporating Expanded Polystyrene ...

    African Journals Online (AJOL)

    Incorporating expanded polystyrene granules in concrete matrix can produce lightweight polystyrene aggregate concrete of various densities. Workability which is an important property of concrete, aects the rate of placement and the degree of compaction of concrete. Inadequate compaction leads to reduction in both ...

  10. Polystyrene calorimeter for electron beam dose measurements

    DEFF Research Database (Denmark)

    Miller, A.

    1995-01-01

    Calorimeters from polystrene have been constructed for dose measurement at 4-10 MeV electron accelerators. These calorimeters have been used successfully for a few years, and polystyrene calorimeters for use at energies down to 1 MeV and being tested. Advantage of polystyrene as the absorbing...

  11. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    Polystyrene-b-alkyl, polystyrene-b-polybutadiene-b-polystyrene, and polystyrene-b-poly(propylene glycol)monotridecyl ether were synthesized using macro initiators and atom transfer radical polymerization or by esterifications of homopolymers. The aim was a maximum molecular weight of 4 kg....../mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...

  12. Nanocomposites of polystyrene-layered double hydroxide (ZnCr) modified with laurate/palmitate: characterization and synthesis in situ; Nanocompositos de poliestireno - hidroxido duplo lamelar (ZnCr) modificados com laurato/palmitato: sintese in situ e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Sartor, Sabrina de B.; Botan, Rodrigo; Lona, Liliane F., E-mail: sabrinabsartor@gmail.com [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Quimica

    2015-07-01

    Polymer nanocomposites have attracted great interest in the scientific community and industry, due to the fact that they show significant improvement in their mechanical and thermal properties. These improvements are attributed to the presence of nano reinforcement added to these materials. In this work nanocomposites of polystyrene (PS) and layered double hydroxide (LDH) of Zinc-Chrome modified with laurate and palmitate anions were synthesized via in situ polymerization. The characterization techniques employed were: Fourier transform infrared spectroscopy (FTIR), X ray diffraction analysis (XRD) and thermogravimetric analysis (TGA). The results obtained by XRD technique show that nanocomposites produced are strongly correlated to the presence of exfoliated morphology in its structure, while the TGA results show that these materials exhibit greater thermal stability when compared to neat PS. (author)

  13. Lenghty reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) polymeric micelles and gels for sustained release of antifungal drugs.

    Science.gov (United States)

    Figueroa-Ochoa, Edgar B; Villar-Alvarez, Eva M; Cambón, Adriana; Mistry, Dharmista; Llovo, José; Attwood, David; Barbosa, Silvia; Soltero, J F Armando; Taboada, Pablo

    2016-08-20

    In this work, we present a detailed study of the potential application of polymeric micelles and gels of four different reverse triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) copolymers (BOnEOmBOn, where n denotes the respective block lengths), specifically BO8EO90BO8, BO14EO378BO14, BO20EO411BO20 and BO21EO385BO21, as effective drug transport nanocarriers. In particular, we tested the use of this kind of polymeric nanostructures as reservoirs for the sustained delivery of the antifungals griseofulvin and fluconazole for oral and topical administration. Polymeric micelles and gels formed by these copolymers were shown to solubilize important amounts of these two drugs and to have a good stability in physiologically relevant conditions for oral or topical administration. These polymeric micellar nanocarriers were able to release drugs in a sustained manner, being the release rate slower as the copolymer chain hydrophobicity increased. Different sustained drug release profiles were observed depending on the medium conditions. Gel nanocarriers were shown to display longer sustained release rates than micellar formulations, with the existence of a pulsatile-like release mode under certain solution conditions as a result of their inner network structure. Certain bioadhesive properties were observed for the polymeric physical gels, being moderately tuned by the length and hydrophobicity of the polymeric chains. Furthermore, polymeric gels and micelles showed activity against the yeast Candida albicans and the mould demartophytes (Trichophyton rubrum and Microsporum canis) and, thus, may be useful for the treatment of different cutaneous fungal infections. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Poly(ethylene-co-butylene) functionalized multi walled carbon nanotubes applied in polypropylene nanocomposites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Marín, Jose Manuel Roman

    2012-01-01

    A novel functionalized multi walled carbon nanotube (MWCNT) was prepared through grafting with α-azido-poly(ethylene-co-butylene) (PEB-N3). The PEB-N3 was prepared through a two step procedure and grafted onto an industrial grade multi walled carbon nanotube (MWCNT) through a highly efficient...... filler had a high degree of discharge from the surface and higher conductivity compared to the pristine filler, illustrating an efficient conductive network in the composites. The composites showed low percolation thresholds of 0.3wt.% (0.15vol.%) as well as improved stability at a range of temperatures...

  15. Oligomer in polystyrene; Porisuchiren chu no origoma

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, J.

    2000-02-05

    In polystyrene used for the housing of electric appliances and cup noodle containers, it is known that oligomers such as dimers and trimers exist, and performance such as machining performance and the thermal instability of polystyrene is affected. Kawamura has evaluated the instant food keeping in the polystyrene container of 32 varieties, and the conversion of the styrene dimers and trimers from the container by cooking. Yamada has proven that the standard of styrene oligomer of about 25 samples confirmed by by-products under polystyrene manufacturing, heat decomposition, material analysis and dissolution test is synthesized, the biological evaluation is carried out for the chemical compound confirmed that dissolving from the container out, anyway does not have the estrogenicity action. In addition, Honishi has announced that the styrene extracted by ethanol which is reported in the Current State Report of the Cup Container for the Food by the Japan Styrene Industry Association, did not show the estrogenicity. (NEDO)

  16. Enhancement of proton conductivity of sulfonated polystyrene ...

    Indian Academy of Sciences (India)

    Enhancement of proton conductivity of sulfonated polystyrene membrane prepared by plasma polymerization process. BHABESH KUMAR NATH, AZIZ KHAN, JOYANTI CHUTIA. ∗. , ARUP RATAN PAL,. HEREMBA BAILUNG, NEELOTPAL SEN SARMA, DEVASISH CHOWDHURY and NIRAB CHANDRA ADHIKARY.

  17. Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

    National Research Council Canada - National Science Library

    Mulkern, Thomas

    1999-01-01

    .... In this work, the incorporation of HBPs in thermoplastic blends was investigated. Several volume fractions of hydroxyl functionalized hyperbranched polyesters were melt blended with nonreactive polystyrene (PS...

  18. Thermal Decomposition of Radiation-Damaged Polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    J Abrefah GS Klinger

    2000-09-26

    The radiation-damaged polystyrene material (''polycube'') used in this study was synthesized by mixing a high-density polystyrene (''Dylene Fines No. 100'') with plutonium and uranium oxides. The polycubes were used on the Hanford Site in the 1960s for criticality studies to determine the hydrogen-to-fissile atom ratios for neutron moderation during processing of spent nuclear fuel. Upon completion of the studies, two methods were developed to reclaim the transuranic (TRU) oxides from the polymer matrix: (1) burning the polycubes in air at 873 K; and (2) heating the polycubes in the absence of oxygen and scrubbing the released monomer and other volatile organics using carbon tetrachloride. Neither of these methods was satisfactory in separating the TRU oxides from the polystyrene. Consequently, the remaining polycubes were sent to the Hanford Plutonium Finishing Plant (PFP) for storage. Over time, the high dose of alpha and gamma radiation has resulted in a polystyrene matrix that is highly cross-linked and hydrogen deficient and a stabilization process is being developed in support of Defense Nuclear Facility Safety Board Recommendation 94-1. Baseline processes involve thermal treatment to pyrolyze the polycubes in a furnace to decompose the polystyrene and separate out the TRU oxides. Thermal decomposition products from this degraded polystyrene matrix were characterized by Pacific Northwest National Laboratory to provide information for determining the environmental impact of the process and for optimizing the process parameters. A gas chromatography/mass spectrometry (GC/MS) system coupled to a horizontal tube furnace was used for the characterization studies. The decomposition studies were performed both in air and helium atmospheres at 773 K, the planned processing temperature. The volatile and semi-volatile organic products identified for the radiation-damaged polystyrene were different from those observed for virgin

  19. Crystallization and degradation behaviors of poly(butylene succinate)/poly(Z-L-lysine) composites

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Licheng; Hu, Jun; Ye, Suwen; Wei, Junchao, E-mail: weijunchao@ncu.edu.cn; Chen, Yiwang

    2014-01-10

    Highlights: • A new biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were successfully prepared through physical blend. • PZlys may greatly affected the crystallization behaviors of PBS without changing its crystalline structure. • The degradation speed of PBS may be greatly accelerated by introduction of PZlys in PBS matrix. - Abstract: A new type of biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were prepared. The crystallization behaviors were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) and the results showed that PZlys can restrict the crystallization of PBS, the crystallization speed of PBS/PZlys were slower than that of PBS, and the crystallization degree of the composites were smaller than that of PBS. However, the WAXD results showed that the incorporation of PZlys did not change the crystalline structure of PBS. The in vitro degradation experiments demonstrated that the degradation speed of the composites were faster than that of PBS. Moreover, the mechanical properties of the composites showed that the composites with a proper composition (for example, 80/20) can keep the mechanical properties of PBS without evident difference, which implied that the composites might be potentially useful as biodegradable materials.

  20. Alternating polyesteramides based on 1,4-butylene terephthalamide: 4. alternating polyesteramides based on glycols (4NT glycol)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Serrano, P.J.M.; Gaymans, R.J.

    1998-01-01

    Polyetheresteramides (PEEAs) have been synthesised in the melt from 1,4-butylene terephthalamide and ethylene or propylene glycols. The ethylene glycols were ethylenediol, diethylene glycol, triethylene glycol and tetraethylene glycol. The propylene glycols were 1,3-propanediol and the mixtures of

  1. Alternating polyesteramides based on 1,4-butylene terephthalamide: 2. alternating polyesteramides based on a single, linear diol (4NTm)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Serrano, P.J.M.; Thuss, E.H.L.; Gaymans, R.J.

    1997-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide and aliphatic diols have been synthesized in the melt in the presence of a titanium catalyst. The influence of diol length on the thermal and mechanical properties was studied. Depending on its structure, the diol took

  2. Production of rotary jet spun ultrathin fibers of poly-butylene adipate-co-terephthalate (PBAT) filled with nanocomposites

    Science.gov (United States)

    Andrade, P. O.; Santo, A. M. E.; Costa, M. M.; Lobo, A. O.

    2017-07-01

    Composite fibers of bioabsorbable poly-butylene adipate-co-terephthalate (PBAT) reinforced with superhydrophilic carbon nanotubes and hydroxyapatite nanocrystals were obtained by rotary jet spinning technique (RJS). The fibers were morphologically and biologically analyzed and found of potential use as scaffold for hard tissue engineering.

  3. Poly(butylene adipate-co-terephthalate) and sunflower head residue composites: Effects of composition and compatibilization on properties

    Science.gov (United States)

    Utilizing the abundant byproducts generated from processing of agricultural materials has sustainable and cost–saving potential benefits. In this work, Sunflower Head Residues (SHR) in 3 different compositions were introduced into biodegradable Poly(butylene adipate-co-terephthalate) (PBAT) matrices...

  4. Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2013-04-01

    Full Text Available Polylactide and poly(butylene succinate-coadipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization...

  5. Polystyrene Chain Growth from Di-End-Functional Polyolefins for Polystyrene-Polyolefin-Polystyrene Block Copolymers

    Directory of Open Access Journals (Sweden)

    Chung Sol Kim

    2017-10-01

    Full Text Available Triblock copolymers of polystyrene (PS and a polyolefin (PO, e.g., PS-block-poly(ethylene-co-1-butene-block-PS (SEBS, are attractive materials for use as thermoplastic elastomers and are produced commercially by a two-step process that involves the costly hydrogenation of PS-block-polybutadiene-block-PS. We herein report a one-pot strategy for attaching PS chains to both ends of PO chains to construct PS-block-PO-block-PS directly from olefin and styrene monomers. Dialkylzinc compound containing styrene moieties ((CH2=CHC6H4CH2CH22Zn was prepared, from which poly(ethylene-co-propylene chains were grown via “coordinative chain transfer polymerization” using the pyridylaminohafnium catalyst to afford di-end functional PO chains functionalized with styrene and Zn moieties. Subsequently, PS chains were attached at both ends of the PO chains by introduction of styrene monomers in addition to the anionic initiator Me3SiCH2Li·(pmdeta (pmdeta = pentamethyldiethylenetriamine. We found that the fraction of the extracted PS homopolymer was low (~20% and that molecular weights were evidently increased after the styrene polymerization (ΔMn = 27–54 kDa. Transmission electron microscopy showed spherical and wormlike PS domains measuring several tens of nm segregated within the PO matrix. Optimal tensile properties were observed for the sample containing a propylene mole fraction of 0.25 and a styrene content of 33%. Finally, in the cyclic tensile test, the prepared copolymers exhibited thermoplastic elastomeric properties with no breakage up over 10 cycles, which is comparable to the behavior of commercial-grade SEBS.

  6. Unique cold-crystallization behavior and kinetics of biodegradable poly[(butylene succinate)-co adipate] nanocomposites: a high speed differential scanning calorimetry study

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2014-08-01

    Full Text Available The poly[(butylene succinate)-co-adipate] (PBSA) nanocomposites (PBSANCs) with five different loadings of organoclay were prepared by melt-blending. The morphological investigation revealed that the degree of dispersion of silicate layers...

  7. The Study of the Microbes Degraded Polystyrene

    Directory of Open Access Journals (Sweden)

    Zhi-Long Tang

    2017-01-01

    Full Text Available Under the observation that Tenebrio molitor and Zophobas morio could eat polystyrene (PS, we setup the platform to screen the gut microbes of these two worms. To take advantage of that Tenebrio molitor and Zophobas morio can eat and digest polystyrene as its diet, we analyzed these special microbes with PS plate and PS turbidity system with time courses. There were two strains TM1 and ZM1 which isolated from Tenebrio molitor and Zophobas morio, and were identified by 16S rDNA sequencing. The results showed that TM1 and ZM1 were cocci-like and short rod shape Gram-negative bacteria under microscope. The PS plate and turbidity assay showed that TM1 and ZM1 could utilize polystyrene as their carbon sources. The further study of PS degraded enzyme and cloning warrants our attention that this platform will be an excellent tools to explore and solve this problem.

  8. Thermal Decomposition of Radiation-Damaged Polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Abrefah, John; Klinger, George S.

    2000-09-26

    The radiation-damaged polystyrene (given the identification name of 'polycube') was fabricated by mixing high-density polystyrene material ("Dylene Fines # 100") with plutonium and uranium oxides. The polycubes were used in the 1960s for criticality studies during processing of spent nuclear fuel. The polycubes have since been stored for almost 40 years at the Hanford Plutonium Finishing Plant (PFP) after failure of two processes to reclaim the plutonium and uranium oxides from the polystyrene matrix. Thermal decomposition products from this highly cross-linked polystyrene matrix were characterized using Gas Chromatograph/Mass Spectroscopy (GC/MS) system coupled to a horizontal furnace. The decomposition studies were performed in air and helium atmospheres at about 773 K. The volatile and semi-volatile organic products for the radiation-damaged polystyrene were different compared to virgin polystyrene. The differences were in the number of organic species generated and their concentrations. In the inert (i.e., helium) atmosphere, the major volatile organic products identified (in order of decreasing concentrations) were styrene, benzene, toluene, ethylbenzene, xylene, nathphalene, propane, .alpha.-methylbenzene, indene and 1,2,3-trimethylbenzene. But in air, the major volatile organic species identified changed slightly. Concentrations of the organic species in the inert atmosphere were significantly higher than those for the air atmosphere processing. Overall, 38 volatile organic species were identified in the inert atmosphere compared to 49 species in air. Twenty of the 38 species in the inert conditions were also products in the air atmosphere. Twenty-two oxidized organic products were identified during thermal processing in air.

  9. Enhanced performance of biodegradable poly(butylene succinate)/graphene oxide nanocomposites via in situ polymerization.

    Science.gov (United States)

    Wang, X W; Zhang, C-A; Wang, P L; Zhao, J; Zhang, W; Ji, J H; Hua, K; Zhou, J; Yang, X B; Li, X P

    2012-05-08

    Poly(butylene succinate) (PBS)/graphene oxide (GO) nanocomposites were facilely prepared via in situ polymerization. The properties of the nanocomposites were studied using FTIR, XRD, and (1)H NMR, and the state of dispersion of GO in the PBS matrix was examined by SEM. The crystallization and melting behavior of the PBS matrix in the presence of dispersed GO nanosheets have been studied by DSC and polarized optical microscopy. Through the mechnical testing machine and DMA, PBS/GO nanocomposites with 3% GO have shown a 43% increase in tensile strength and a 45% improvement in storage modulus. This high performance of the nanocomposites is mainly attributed to the high strength of graphene oxide combined with the strong interfacial interactions in the uniformly dispersed PBS/GO nanocomposites.

  10. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    Science.gov (United States)

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  11. Influence of Teflon substrate on crystallization and enzymatic degradation of polymorphic poly(butylene adipate)

    DEFF Research Database (Denmark)

    Ning, Zhenbo; Nielsen, Ronnie Bo Højstrup; Zhao, Lifen

    2014-01-01

    Oriented and non-oriented Teflon films, which were found to have the same crystalline structure, but different surface morphologies, were used to sandwich poly(butylene adipate) (PBA) films during isothermal crystallization. It was found that both the Teflon surface structure and the PBA...... polymorphic structure are the determining factors to induce epitaxial crystallization. The oriented Teflon film was able to induce epitaxial crystallization of PBA alpha crystal, while the non-oriented Teflon did not induce any epitaxial crystallization of PBA. Epitaxial crystallization did not occurred...... for PBA beta crystals between neither the oriented nor the non-oriented Teflon films. The enzymatic degradation rate of PBA films was not determined by the epitaxial crystallization, in fact it was still dependent on the polymorphic crystal structure of PBA. The morphological changes of PBA films after...

  12. Gamma radiation effects on random copolymers based on poly(butylene succinate) for packaging applications

    Science.gov (United States)

    Negrin, M.; Macerata, E.; Consolati, G.; Quasso, F.; Genovese, L.; Soccio, M.; Giola, M.; Lotti, N.; Munari, A.; Mariani, M.

    2018-01-01

    Within the context of new bioplastic materials, poly(butylene succinate) (PBS) and four novel poly(butylene/thiodiethylene succinate) random copolymers (PBS-PTDGS), in sheets as well as in films, were exposed to gamma radiation, in air and in water, and their behavior along with the effect on their biodegradability was investigated. The molecular weight data obtained from gel permeation chromatography indicate that the sensibility to radiation increases with the amount of sulfur-containing co-unit (TDGS). At 200 kGy the average molecular weight of PBS film halves, while for P(BS60TDGS40) the residual molecular weight is about 20%. The calculated intermolecular crosslink Gx and scissioning Gs yields confirmed that degradation is predominant over crosslink for all the aliphatic systems. As shown by thermal analyses, gamma radiation affects the thermal properties, leading to an increased crystallinity of the systems, remarkable for PBS, and lower decomposition temperatures. Variations of crystallinity with the increasing absorbed dose were confirmed also by PALS analyses. Water contact angle measurements revealed post-irradiation wettability alterations that could positively affect polymer biodegradability. In particular, when irradiated in water at 100 kGy PBS film exhibits a water contact angle decrease of about 17%, indicating an enhanced wettability. After degradation in compost, changes in the surface morphology were observed by means of SEM and sample weight losses were determined, at different extent, according to the irradiation environment. Interestingly, after 52 days in compost PBS films, both pristine and irradiated in air at 25 kGy, showed a residual weight of about 60%, while the ones irradiated in water at 25 kGy of about 44%. Experimental data confirmed that gamma irradiation could represent a viable treatment to enhance biodegradation in compost of PBS and PBS-based copolymers.

  13. Lightweight High Strength Concrete with Expanded Polystyrene Beads

    OpenAIRE

    Subhan, Tengku Fitriani L

    2006-01-01

    This paper is a literature study about lightweight high strength concrete by incorporating expanded polystyrene beads. Basically polystyrene is disposal material from packaging industry. However, after being processed in a special manner, polystyrene can be expanded and used as lightweight concrete making material. Therefore, the use of expanded polystyrene beads in concrete is not only beneficial for engineering studies but also provide solution for the environmental problem

  14. Simulative calculation of bromo-polystyrene mechanical properties

    CERN Document Server

    Wang Chao; Tang Yong Jian

    2002-01-01

    The non-crystal model of polystyrene and bromo-polystyrene was established with the help of simulative software in the computer. DREIDING was chosen as force field and its parameters is modified according to the published data. Based on the calculation results and other published data the mechanism properties of polystyrene and bromo-polystyrene, such as bulk module, Yong's module and Poisson's ratios, were discussed

  15. Activity of Antimicrobial Silver Polystyrene Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Palomba

    2012-01-01

    Full Text Available A simple technique based on doping polymers with in situ generated silver nanoparticles (Ag/PS films has been developed. In particular, an antiseptic material has been prepared by dissolving silver 1,5-cyclooctadiene-hexafluoroacetylacetonate in amorphous polystyrene, and the obtained solid solution has been heated for ca. 10 s at a convenient temperature (180°C. Under such conditions the metal precursor decomposes producing silver atoms that diffuse into the polymer and clusterize. The antimicrobial characteristics of the resulting polystyrene-based material have been accurately evaluated toward Escherichia coli (E. coli comparing the cytotoxicity effect of 10 wt.% and 30 wt.% (drastic and mild annealing silver-doped polystyrene to the corresponding pure micrometric silver powder. Two different bacterial viability assays were performed in order to demonstrate the cytotoxic effect of Ag/PS films on cultured E. coli: (1 turbidimetric determination of optical density; (2 BacLight fluorescence-based test. Both methods have shown that silver-doped polystyrene (30 wt.% provides higher antibacterial activity than pure Ag powder, under similar concentration and incubation conditions.

  16. Compressive and Tensile Strength of Expanded Polystyrene Beads Concrete

    OpenAIRE

    Subhan, Tengku Fitriani L

    2005-01-01

    Penelitian ini betujuan untuk mempelajari property dari beton ringan yang mengandung expanded polystyrene beads, yaitu kuat tekan (compressive strength) dan kuat tarik (tensile strength). Property tersebut kemudian dibandingkan dengan beton normal (beton tanpa expanded polystyrene beads) sebagai campuran pengontrol. Hasil penelitian ini menunjukkan bahwa jumlah polystyrene beads yang dimasukkan sebagai campuran beton mempengaruhi property beton; yaitu dapat menurunkan kuat tekan beton. Tetapi...

  17. Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mehrabzadeh

    2013-01-01

    Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

  18. Nonlinear branch-point dynamics of multiarm polystyrene

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Denberg, Martin

    2006-01-01

    Two branched polystyrene melts with narrow molar mass distribution have been synthesized: a multiarm An-C-C-An pom-pom polystyrene and an An-C asymmetric star polystyrene where n is the number of arms. The pom-pom and the asymmetric star have molar masses of Mw ) 300 kg/mol and Mw ) 275 kg...... polystyrene, the measured transient elongational viscosity is not consistent with a rheological constitutive equation that is separable in time and strain. Contrary to this situation, however, for pom-pom polystyrene, the transient elongational viscosity may be described by a time-strain separable...

  19. Aging phenomena in polystyrene thin films

    OpenAIRE

    Fukao, Koji; Koizumi, Hiroki

    2008-01-01

    The aging behavior is investigated for thin films of atactic polystyrene through measurements of complex electric capacitance. During isothermal aging process the real part of the electric capacitance increases with aging time, while the imaginary part decreases with aging time. This result suggests that the aging time dependence of the real and imaginary parts are mainly associated with change in thickness and dielectric permittivity, respectively. In thin films, the thickness depends on the...

  20. Uniaxial Elongational viscosity of bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The startup and steady uniaxial elongational viscosity have been measured for three bidisperse polystyrene (PS) melts, consisting of blends of monodisperse PS with molecular weights of 52 kg/mole or 103 kg/mole and 390 kg/mole. The bidisperse melts have a maximum in the steady elongational...... viscosity, of up to a factor of 7 times the Trouton limit of 3 times the zero-shear viscosity....

  1. Spectrometric characteristics of polystyrene scintillation films

    CERN Document Server

    Astvatsaturov, A R; Gavalyan, V B; Gavalyan, V G

    1999-01-01

    The spectrometric characteristics of five types of polystyrene scintillation films with thicknesses of 10, 30, 50 and 80 mu m and of analogous 250 mu m thick plates irradiated with sup 2 sup 3 sup 9 Pu, sup 2 sup 3 sup 8 Pu and sup 2 sup 2 sup 6 Ra sources of alpha-particles have been studied. The prospects of utilization of scintillation films as radiators for detection of heavy charged particles and measurement of their energy was experimentally shown.

  2. Designing Zirconium Coated Polystyrene Colloids and Application

    Directory of Open Access Journals (Sweden)

    Diana Chira

    2009-01-01

    Full Text Available A simple technique has been developed to prepare core colloids that are modified using zirconium oxychloride, based on heating a solution of core colloid composites, consisting of poly (ethylenimine (PEI and zirconium oxychloride. The interaction of zirconium oxychloride with the polystyrene (PS core colloids has been investigated using Fourier transform-infrared spectroscopy (FT-IR, energy dispersive X-ray spectroscopy (EDX, and scanning electron microscopy (SEM data. FT-IR studies confirm the occurrence of amine groups present in PEI which are oxidized to carboxyl groups after the reaction. The EDX data and the SEM images confirm the presence of zirconium particles immobilized on the polystyrene surfaces. Demeton, a highly toxic nerve agent, was used due to its ability to easily bind through its organophosphate group illustrating a practical application of the PS-PEI-Zr particles. Attenuated Total Reflection (ATR Spectroscopy was used to assess the interactions between the toxic nerve agent demeton-S and the PS-PEI-Zr particles. The results show that the presented technique for coating polystyrene core colloids with zirconium was successfully accomplished, and the newly formed particles easily bond with demeton agents through the P=O functional group.

  3. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay.

    Science.gov (United States)

    Chen, Jung-Hung; Yang, Ming-Chien

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Starch/poly (butylene adipate-co-terephthalate/montmorillonite films produced by blow extrusion

    Directory of Open Access Journals (Sweden)

    Rodrigo A. L. Santos

    2014-07-01

    Full Text Available This study aims to prepare biodegradable films from cassava starch, poly (butylene adipate-co-terephthalate (PBAT, and montmorillonite (MMT using blow-extrusion process and analyze the effects of different types and concentrations of MMT on the microstructure, physicochemical, and mechanical properties of the resulting films. The films were produced by blending 30% of PBAT with glycerol (17.5%, starch (49.0-52.5%, and four different types of montmorillonite (Cloisite® Na+, 10A, 15A, and 30B at two different concentrations (1.75% and 3.5%. All the films prepared in this study showed an increase in the basal spacing of MMT layers. In particular, the films with 10A and 30B showed the highest increase in intercalation basal spacing, suggesting the formation of intercalated composites. The addition of nanoclays decreased the elongation of films. The addition of Cloisite® 10A resulted in films with the lowest WVP values and the highest stability to water adsorption under different RH conditions.

  5. Structure and properties of organically modified poly(butylene adipate-co-terephthalate) based nanocomposites

    Science.gov (United States)

    Rasyida, A.; Fukushima, K.; Yang, M.-C.

    2017-07-01

    Poly (butylene adipate-co-terephthalate (PBAT) nanocomposites were prepared by melt blending PBAT with 5 wt.% of modified or unmodified montmorillonites (MMT). The effect of the presence of organic modifiers in MMT on the morphological, crystalline, thermal, and mechanical properties of PBAT nanocomposites was evaluated. The dispersion and distribution of the clays were studied by using wide angle X-ray analysis (WAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis. Materials characterization techniques included: contact angle measurements, differential scanning calorimetry (DSC), thermogravimetry (TGA) and surface hardness analysis. As general results, nanocomposites exhibited different level of clay dispersion depending on the clay/organic modifier’s chemical affinity with the polymer. Contact angle measurements show increases in the hydrophobicity level of PBAT based CLO30B, this could depict its high potential for packaging applications. In addition, Thermal analysis showed that clays partially hindered kinetics and extent of PBAT crystallization on cooling. In general, thermal properties of PBAT were improved by addition of clays, for a barrier effect of the nanoparticle towards polymer decomposition products ablation. In parallel, addition of clays led to enhancements in polymer hardness. These properties were found to be apparently influenced by clay dispersion level and chemical compatibility between the organic modifier and polymer matrix.

  6. The tensile strength test of thermoplastic materials based on poly(butylene terephtalate

    Directory of Open Access Journals (Sweden)

    Rzepecka Anna

    2017-01-01

    Full Text Available Thermoplastic composites go toward making an increasingly greater percentage of all manufacturing polymer composites. They have a lot of beneficial properties and their manufacturing using injecting and extrusion methods is a very easy and cheap process. Their properties significantly overtake the properties of traditional materials and it is the reason for their use. Scientists are continuously carrying out research to find new applications of composites materials in new industries, not only in the automotive or aircraft industry. When thermoplastic composites are manufactured a very important factor is the appropriate accommodation of tensile strength to their predestination. Scientists need to know the behaviour of these materials during the impact of different forces, and the factors of working in normal conditions too. The main aim of this article was macroscopic and microscopic analysis of the structure of thermoplastic composites after static tensile strength test. Materials which were analysed were thermoplastic materials which have poly(butylene terephthalate – PBT matrix reinforced with different content glass fibres – from 10% for 30%. In addition, research showed the necessary force to receive fracture and set their distinguishing characteristic down.

  7. Ethylene oxide-block-butylene oxide copolymer uptake by silicone hydrogel contact lens materials

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Yuchen [Department of Materials Science and Engineering, University of Florida, Rhines Hall 100, Gainesville, FL 32611 (United States); Ketelson, Howard [Alcon Inc., Research and Development, Vision Care, 6201 South Freeway, Fort Worth, TX 76134 (United States); Perry, Scott S., E-mail: ssp@mse.ufl.edu [Department of Materials Science and Engineering, University of Florida, Rhines Hall 100, Gainesville, FL 32611 (United States)

    2013-05-15

    Four major types of silicone hydrogel contact lens material have been investigated following treatments in aqueous solutions containing poly(ethylene oxide) and poly(butylenes oxide) block copolymer (EO–BO). The extent of lens surface modification by EO–BO and the degree of bulk uptake were studied using X-ray photoelectron spectroscopy (XPS) and ultra-performance liquid chromatography (UPLC), respectively. The experimental results suggest that different interaction models exist for the lenses, highlighting the influence of both surface and bulk composition, which greatly differs between the lenses examined. Specifically, lenses with hydrophilic surface treatments, i.e., PureVision{sup ®} (balafilcon A) and O{sub 2}OPTIX (lotrafilcon B), demonstrated strong evidence of preferential surface adsorption within the near-surface region. In comparison, surface adsorption on ACUVUE{sup ®} Oasys{sup ®} (senofilcon A) and Biofinity{sup ®} (comfilcon A) was limited. As for bulk absorption, the amount of EO–BO uptake was the greatest for balafilcon A and comfilcon A, and least for lotrafilcon B. These findings confirm the presence of molecular concentration gradients within the silicone hydrogel lenses following exposure to EO–BO solutions, with the nature of such concentration gradients found to be lens-specific. Together, the results suggest opportunities for compositional modifications of lenses for improved performance via solution treatments containing surface-active agents.

  8. Ethylene oxide-block-butylene oxide copolymer uptake by silicone hydrogel contact lens materials

    Science.gov (United States)

    Huo, Yuchen; Ketelson, Howard; Perry, Scott S.

    2013-05-01

    Four major types of silicone hydrogel contact lens material have been investigated following treatments in aqueous solutions containing poly(ethylene oxide) and poly(butylenes oxide) block copolymer (EO-BO). The extent of lens surface modification by EO-BO and the degree of bulk uptake were studied using X-ray photoelectron spectroscopy (XPS) and ultra-performance liquid chromatography (UPLC), respectively. The experimental results suggest that different interaction models exist for the lenses, highlighting the influence of both surface and bulk composition, which greatly differs between the lenses examined. Specifically, lenses with hydrophilic surface treatments, i.e., PureVision® (balafilcon A) and O2OPTIX (lotrafilcon B), demonstrated strong evidence of preferential surface adsorption within the near-surface region. In comparison, surface adsorption on ACUVUE® Oasys® (senofilcon A) and Biofinity® (comfilcon A) was limited. As for bulk absorption, the amount of EO-BO uptake was the greatest for balafilcon A and comfilcon A, and least for lotrafilcon B. These findings confirm the presence of molecular concentration gradients within the silicone hydrogel lenses following exposure to EO-BO solutions, with the nature of such concentration gradients found to be lens-specific. Together, the results suggest opportunities for compositional modifications of lenses for improved performance via solution treatments containing surface-active agents.

  9. Effect of Rubberwood Content on Biodegradability of Poly(butylene succinate Biocomposites

    Directory of Open Access Journals (Sweden)

    Hemhong Anankaphong

    2015-01-01

    Full Text Available Poly(butylene succinate (PBS biocomposites incorporated with rubberwood powder (RWP were fabricated with various RWP weight fractions (i.e., 0 to 40% wt by injection moulding process. The soil burial test was employed to examine the biodegradability of such biocomposites under outdoor environment for 60 days. The physical appearance, percentage weight loss, chemical structure, and mechanical properties before and after the soil burial test were determined. Apparent changes in physical appearance of the biocomposites from optical micrographs were detected in terms of surface morphology and colour. The percentage of crystallinity of PBS/RWP biocomposites was studied by the X-ray diffraction (XRD technique, and the XRD pattern revealed a decrease in percentage of crystallinity due to enhancing RWP weight fractions. This may be attributed to a presence of rubberwood powders providing more disordered molecular chain arrangement of PBS matrix and also an agglomeration of the rubberwood powder content at greater concentration as seen in SEM micrographs. With increasing RWP weight fractions and burial time, the results exhibited a considerable change in chemical structure (essentially ester linkage due to biodegradation mechanism of PBS, relatively greater percentage weight loss, and a substantial decrease in flexural properties. Consequently, the results indicate that incorporating RWP enhances biodegradability of PBS/RWP biocomposites; that is, the biodegradation rate of biocomposites increases with increasing RWP weight fractions and burial time.

  10. Thermal and Mechanical Properties of Poly(butylene succinate Films Reinforced with Silica

    Directory of Open Access Journals (Sweden)

    Sangviroon Nanthaporn

    2015-01-01

    Full Text Available In recent year, bioplastics have become more popular resulting from the growing concerns on environmental issues and the rising fossil fuel price. However, their applications were limited by its mechanical and thermal properties. The aim of this research is thus to improve mechanical and thermal properties of PBS bioplastic films by reinforcing with silica. Due to the poor interfacial interaction between the PBS matrix and silica, glycidyl methacrylate grafted poly(butylene succinate (PBS-g-GMA was used as a compatibilizer in order to improve the interaction between bioplastic films and filler. PBS-g-GMA was prepared in a twin-screw extruder and analyzed by the FTIR spectrometer. PBS and silica were then mixed in a twin-screw extruder and processed into films by a chill-roll cast extruder. The effects of silica loading on thermal and mechanical properties of the prepared bioplastic films were investigated. It was found that the mechanical properties of PBS/silica composite films were improved when 1%wt of silica was added. However, the mechanical properties decreased with increasing silica loading due to the agglomeration of silica particles. The results also show that the silica/PBS films with PBS-g-GMA possessed improved mechanical properties over the films without the compatibilizer.

  11. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid/Poly(Butylene Succinate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Amita Bhatia

    2012-01-01

    Full Text Available Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid (PLA, poly(butylene succinate (PBS, and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was considered to have a mixed morphology of intercalated and delaminated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and more than 3 wt% of clay content. However, the average particle size of the dispersed PBS phase was reduced significantly from 7 μm to 30–40 nm with the addition of clay in the blend. The oxygen barrier property was improved significantly as compared to the water vapor. A model based on gas barrier property was used for the validation of the oxygen relative permeabilities of PLA/PBS/clay nanocomposites. PLA/PBS/clay nanocomposites validated the Bharadwaj model up to 3 wt% of clay contents only, while for nanocomposites of higher clay contents the Bharadwaj model was invalid due to the clusters and agglomerates formed.

  12. Thermal Treatment Temperature and Time Dependence of Contact Angle of Water on Fluorinated Polystyrene as Hydrophobic Film Coating

    Science.gov (United States)

    Tolentino, M. S.; Carpena, J. F.; Javier, R. M.; Aquino, R. R.

    2017-06-01

    The study focuses on the synthesis of fluorinated polystyrene (F-PS) as a hydrophobic film coating and on the investigation of the consequent effects of thermal treatment time and treatment temperature on its contact angle. The fluorinated polystyrene is synthesized via Friedel-Crafts acylation of the benzoic rings by electrophilic substitution of trifluoroacetic anhydride in the presence of AlCl3 in an environment of dichloromethane as the aprotic solvent with a reaction temperature of 36°C. The reaction yielded fluorinated polystyrene characterized by a solid brown substance. FT-IR analysis of the substance had shown band peaks at 1150 cm-1, a wavenumber indicating the presence of fluorine in the synthesized material, which lowers its surface energy. SEM images of the F-PS show nucleation sites giving rise to hierarchical structures on the surface of the material due to the action of fluorination. The contact angle of fluorinated polystyrene, upon application of thermal treatment, increased to as much as 29.26% when compared to the unmodified polystyrene manifesting a preferentially more hydrophobic behavior. It was also found that the contact angle increases linearly with treatment temperature while statistical analysis shows that thermal treatment time has no significant effect on the hydrophobicity of the F- PS.

  13. Incorporation of pyrene in polypyrrole/polystyrene magnetic beads.

    Science.gov (United States)

    Głowala, Paulina; Budniak, Adam; Krug, Pamela; Wysocka, Barbara; Berbeć, Sylwia; Dec, Robert; Dołęga, Izabela; Kacprzak, Kamil; Wojciechowski, Jarosław; Kawałko, Jakub; Kępka, Paweł; Kępińska, Daria; Kijewska, Krystyna; Mazur, Maciej

    2014-10-15

    Pyrene, a fluorescent dye, was incorporated into polystyrene particles coated with polypyrrole. The incorporation was achieved by treating the polypyrrole/polystyrene (PPy/PS) beads in a tetrahydrofuran (THF) solution of the pyrene fluorophore followed by rinsing with methanol. The polystyrene cores of the beads swell in THF, allowing penetration of pyrene molecules into the polystyrene structure. The addition of methanol causes contraction of the swollen polystyrene, which encapsulates the dye molecules inside the beads. It is shown that the polypyrrole coating is permeable with respect to both the dye and the solvent, allowing the transport of molecules between the polystyrene cores and the contacting solution. The polypyrrole adlayer can be used as a matrix for the incorporation of magnetic nanoparticles. Embedded particles provide magnetic functionality to the PPy/PS beads. It is demonstrated that the pyrene-loaded beads can be manipulated with an external magnetic field. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Fabrication and characterization of shape memory polystyrene foams

    Science.gov (United States)

    Yao, Yongtao; Xiang, Pei; Leng, Jinsong

    2013-04-01

    In this project, shape memory polystyrene foam was fabricated from shape memory polystyrene and ethyl acetate/n-hexane as physical foaming agent based on suspension polymerization method. The foam of uniform pore structure with porosity ranging from 36%~45% have been made successfully. Both shape memory properties and physical properties were characterized. Shape memory polystyrene foam exhibited good shape memory properties-- completely recovery the initial undeformed shape after multiple cycles. The higher thermal stability was achieved compared with pure shape memory polystyrene. The glassy state property of the foam was increased from 75°C to 85°C as the content of filler increased from 0 to 30%.

  15. Integrated lenses in polystyrene microfluidic devices

    KAUST Repository

    Fan, Yiqiang

    2013-04-01

    This paper reports a new method for integrating microlenses into microfluidic devices for improved observation. Two demonstration microfluidic devices were provided which were fabricated using this new technique. The integrated microlenses were fabricated using a free-surface thermo-compression molding method on a polystyrene (PS) sheet which was then bonded on top of microfluidic channels as a cover plate, with the convex microlenses providing a magnified image of the channel for the easier observation of the flow in the microchannels. This approach for fabricating the integrated microlens in microfluidic devices is rapid, low cost and without the requirement of cleanroom facilities. © 2013 IEEE.

  16. Solid polystyrene and deuterated polystyrene light output response to fast neutrons

    Science.gov (United States)

    Simpson, R.; Danly, C.; Glebov, V. Yu.; Hurlbut, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C.

    2016-04-01

    The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

  17. Solid polystyrene and deuterated polystyrene light output response to fast neutrons.

    Science.gov (United States)

    Simpson, R; Danly, C; Glebov, V Yu; Hurlbut, C; Merrill, F E; Volegov, P L; Wilde, C

    2016-04-01

    The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

  18. Crystallization behavior of partially miscible biodegradable poly(butylene succinate)/poly(ethylene succinate) blends

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi-Song [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Zeng, Jian-Bing, E-mail: zengjianbing@scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Li, Shao-Long [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Wang, Yu-Zhong, E-mail: yzwang@scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials (ERCPM-MoE), College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China)

    2012-02-10

    Graphical abstract: Crystallization rate of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. The rich component formed a continuous phase and the other formed a dispersed phase of the blend. Crystal structures of PBS and PES were almost unchanged after blending with each other. Highlights: Black-Right-Pointing-Pointer PBS/PES blend systems are partially miscible. Black-Right-Pointing-Pointer Blending did not change the crystallization mechanisms of PBS and PES not affects the crystallization rates. Black-Right-Pointing-Pointer The rich component formed the continuous phase while the poor component formed the dispersed phase of the blends. Black-Right-Pointing-Pointer Crystal structures of PBS and PES were almost unchanged after blending with each other. - Abstract: Biodegradable blend of poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility of the blends was investigated by differential scanning calorimetry (DSC). The results indicated that PBS and PES were partially miscible. Crystallization kinetics, crystalline morphology and crystal structure of the blends were studied by DSC, polarized optical microscope (POM), and wide-angle X-ray diffraction (WAXD), respectively. Nonisothermal and isothermal crystallization kinetics suggested that the crystallizability of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. POM observation illustrated that the rich component formed a continuous phase and the other formed a dispersed phase. The results of WAXD indicated that the crystal structures of PBS and PES were almost unchanged before and after blending, since the positions of characteristic diffraction peaks of both components remain almost unchanged.

  19. Preparation and characterization of nanocomposite of maleated poly(butylene adipate-co-terephthalate) with organoclay

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jung-Hung [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Yang, Ming-Chien, E-mail: myang@mail.ntust.edu.tw [Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2015-01-01

    Nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) with montmorillonite (MMT) nanoparticles were prepared via melt blending. Natural MMT was modified by either octadecylamine (ODA) or dihexylamine (DHA). Neat PBAT was grafted with maleic anhydride via melt grafting process. Intercalation of the organoclay in the PBAT matrix was studied by X-ray diffraction (XRD). From the results of transmission electron microscope (TEM), the dispersion of ODA-modified MMT in the PBAT matrix was more homogeneous than that of neat MMT. The addition of organoclay can increase the cooling crystallization temperature of PBAT, as observed by differential scanning calorimetry (DSC). Furthermore, the results of thermogravimetric analyzer (TGA) showed that the addition of ODA-modified MMT can improve the thermal stability of PBAT nanocomposites. The tensile strength was little affected, while the Young's modulus was increased with the addition of nanoclays. The grafting of PBAT with MA resulted in improved interaction between polymer matrix and the silicate layer due to the formation of chemical/physical bonds, thus the dispersion of organoclays was enhanced. By grafting PBAT with MA, the enzymatic biodegradation of the nanocomposite was increased, while the photodegradation of PBAT was little affected. Furthermore, the transmission of water vapor was reduced by the addition of organically modified MMT. - Highlights: • Nanocomposites of PBAT and clay nanoparticles were prepared via melting blending. • Maleated PBAT/organoclays exhibited higher Young's moduli than neat PBAT/neat MMT. • The enzymatic degradation of PBAT composites was improved by maleation. • Maleation caused little effect on the photodegradation of PBAT. • Organoclays retarded the permeation of water vapor through PBAT composites.

  20. Filtration application from recycled expanded polystyrene.

    Science.gov (United States)

    Shin, C

    2006-10-01

    Water-in-oil emulsion with drop size less than 100 mum is difficult to separate. Coalescence filtration is economical and effective for separation of secondary dispersions. Coalescence performance depends on flow rate, bed depth, fiber surface properties, and drop size. The amount of surface area of the fibers directly affects the efficiency. A new recycling method was investigated in the previous work in which polystyrene (PS) sub-mum fibers were electro-spun from recycled expanded polystyrene (EPS). These fibers are mixed with micro glass fibers to modify the glass fiber filter media. The filter media are tested in the separation of water droplets from an emulsion of water droplets in oil. The experimental results in this work show that adding nanofibers to conventional micron sized fibrous filter media improves the separation efficiency of the filter media but also increases the pressure drop. An optimum in the performance occurs (significant increase in efficiency with minimal increase in pressure drop) with the addition of about 4% by mass of 500 nm diameter PS nanofibers to glass fibers for the filters.

  1. Polystyrene cups and containers: styrene migration.

    Science.gov (United States)

    Tawfik, M S; Huyghebaert, A

    1998-07-01

    The level of styrene migration from polystyrene cups was monitored in different food systems including: water, milk (0.5, 1.55 and 3.6% fat), cold beverages (apple juice, orange juice, carbonated water, cola, beer and chocolate drink), hot beverages (tea, coffee, chocolate and soup (0.0, 0.5, 1, 2, and 3.6% fat), take away foods (yogurt, jelly, pudding and ice-cream), as well as aqueous food simulants (3% acetic acid, 15, 50, and 100% ethanol) and olive oil. Styrene migration was found to be strongly dependent upon the fat content and storage temperature. Drinking water gave migration values considerably lower than all of the fatty foods. Ethanol at 15% showed a migration level equivalent to milk or soup containing 3.6% fat. Maximum observed migration for cold or hot beverages and take-away foods was 0.025% of the total styrene in the cup. Food simulants were responsible for higher migration (0.37% in 100% ethanol). A total of 60 food samples (yogurt, rice with milk, fromage, biogardes, and cheese) packed in polystyrene containers were collected from retail markets in Belgium, Germany, and the Netherlands. The level of styrene detected in the foods was always fat dependent.

  2. Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

    Directory of Open Access Journals (Sweden)

    Jutakan Boonmee

    2016-01-01

    Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

  3. Design, synthesis and physical properties of poly(styrene ...

    Indian Academy of Sciences (India)

    Administrator

    content, 10% gravimetric loss was increased from 481 to 497 °C, while glass transition improved from 123 to. 136 °C (better than neat SBS but lower than PTAS). The blends also established higher tensile strength. (52∙40–59∙96 MPa) relative to SBS. Fine balance of properties renders new SBS/PTAS, potential engineering.

  4. Synthesis, magnetic and spectral studies on polystyrene-anchored ...

    Indian Academy of Sciences (India)

    Administrator

    The Cu(II) complex is paramagnetic with square planar structure; the Ni(II) complex is diamagnetic with square planar structure; the Zn(II) and Cd(II) complexes are diamagnetic and have tetrahedral structure; the Mn(II) and Fe(III) complexes are paramagnetic and have octahedral structure; the MoO2(II) and UO2(II) ...

  5. Expanded Polystyrene Re-Expansion Analysis Following Impact Compression

    Science.gov (United States)

    2015-03-04

    USAARL Report No. 2015-08 Expanded Polystyrene Re-Expansion Analysis Following Impact Compression By Mark S. Adams Frederick Brozoski Katie...13 iv This page is intentionally left blank. 1 Introduction Expanded bead polystyrene (EPS) is widely...steep rise in the stress-strain curve and little or no energy attenuation. When compressive stresses are removed, EPS foam will partially re- expand

  6. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2006-01-01

    The start-up and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 and 103 kg/mole, and for three bidisperse polystyrene melts. The monodisperse melts show a maximum in the steady elongational viscosity vs. the elongational...

  7. production of particle boards using polystyrene and bamboo wastes

    African Journals Online (AJOL)

    This investigation was able to produce incredibly strong particleboards using bamboo and resinous material obtained from Polystyrene wastes. The particleboards were prepared by mixing the bamboo fibres and Polystyrene based resin (PBR) followed by flat press process at different ratio (v/v). Physical properties were ...

  8. Polystyrene as a zwitter resist in electron beam lithography based ...

    Indian Academy of Sciences (India)

    Wintec

    polystyrene (Mw, 2,600,000) in toluene was spin coated. (3000 rpm, 60 s) on the substrate to form a thin film. Polystyrene of a higher molecular weight was preferred due to its enhanced sensitivity (Imamura et al 1982; Khoury and Ferry 1996). The film thickness was measured using a Wyko NT1100 (Veeco, USA) optical ...

  9. RESEARCHES OF WORKING LIFE OF FOAM POLYSTYRENE OF BUILDING APPOINTMENT

    Directory of Open Access Journals (Sweden)

    Guyumdzhjan Perch Pogosovich

    2012-09-01

    Full Text Available Results of experimental researches of physicomechanical properties of foam polystyrene thermal insulation materials are presented in article. The operational resource was defined on materials subject to ageing, action of liquid excited environments and atmospheric impacts. The destructive processes leading to destruction of foam polystyrene are revealed.

  10. Stress relaxation of bi-disperse polystyrene melts

    DEFF Research Database (Denmark)

    Hengeller, Ludovica; Huang, Qian; Dorokhin, Andriy

    2016-01-01

    We present start-up of uniaxial extension followed by stress relaxation experiments of a bi-disperse 50 % by weight blend of 95k and 545k molecular weight polystyrene. We also show, for comparison, stress relaxation measurements of the polystyrene melts with molecular weight 95k and 545k, which...

  11. Pegylated polystyrene particles as a model system for artificial cells

    NARCIS (Netherlands)

    Meng, Fenghua; Engbers, G.H.M.; Gessner, Andrea; Müller, Reiner H.; Feijen, Jan

    2004-01-01

    Pegylated polystyrene particles (PS-PEG) were prepared as a model system for artificial cells, by modification of carboxyl polystyrene particles (PS-COOH) with homo- and hetero-bifunctional polyethylene glycols (PEG, MW 1500, 3400, and 5000) containing an amino end group for immobilization and an

  12. Fabrication of polystyrene/gold nanotubes and nanostructure-controlled growth of aluminate.

    Science.gov (United States)

    Zhu, Haifeng; Ai, Sufen; He, Qiang; Cui, Yue; Li, Junbai

    2007-07-01

    Direct adsorption of gold nanoparticles in the inner of alumina template and following immersion of polystyrene (PS) dichloromethane solution in the template resulted in the fabrication of composite nanotubes of PS and gold nanoparticles. Several methods have been used to characterize the tubular structure. Nanostructured sodium aluminates were formed when the anodic alumina oxide membrane was dissolved by the sodium hydroxide. A "flower" shape was found after etching the template while the synthesis process was recorded as function of a time. The results demonstrate that the shape and size of the aluminates nanostructure can be controlled by etching time and the pore diameter of the alumina membrane.

  13. Numerical test on polystyrene tunnel seismic-isolation material

    Directory of Open Access Journals (Sweden)

    He Jianping

    2016-09-01

    Full Text Available Stress-strain mechanical properties of polystyrene foam plastic material were tested under different loading conditions. An empirical constitutive model for describing metal materials was proposed for the polystyrene plastic foam. The static and dynamic tests results show that the ductility and watertightness of the polystyrene plastic foam are significantly improved. At the same time, in order to check its seismic-isolation property, the high-performance foam concrete as filling materials of Galongla tunnel in Tibet was simulated by FEM. The simulated results show that the polystyrene plastic foam can remarkably decrease the stress and the plastic zone in final lining, so it can effectively reduce the seismic damage of the tunnel. Considering the seismic-isolation property and low price of polystyrene plastic foam, it is a good reference for the anti-seismic design of tunnels in high intensity zones.

  14. Preparation and thermal properties of polystyrene/silica nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Bera, O., E-mail: oskarbera@gmail.com [Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad (Serbia); Pilic, B.; Pavlicevic, J.; Jovicic, M. [Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000 Novi Sad (Serbia); Hollo, B.; Szecsenyi, K. Meszaros [Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, 2100 Novi Sad (Serbia); Spirkova, M. [Institute of Macromolecular Chemistry AS CR v.v.i., Heyrovskeho Nam. 2, 16206 Prague (Czech Republic)

    2011-03-10

    A series of polystyrene/silica nanocomposites with different inorganic nanofiller content were prepared by evaporating of toluene solvent. The weight fraction of silica nanoparticles of an average diameter of 7 nm treated with hexamethyldisilazane was varied (2, 5, 10, 15 and 30 wt.%). The polystyrene nanocomposite morphology was studied by scanning electron microscopy. The thermal stability of the samples was determined using thermogravimetry, coupled with differential scanning calorimetry. The influence of the filler content on glass transition temperature of polystyrene/silica nanocomposites was followed by differential scanning calorimetry. It was found that the polystyrene glass transition temperature was influenced by the hydrophobic silica content. A mathematical method to describe the glass transition temperature dependence on the polystyrene/silica ratio is proposed. According to the experimental results and calculations, the highest thermal stability of the nanocomposite belongs to 18% silica content.

  15. Interaction between polystyrene spheres by atomic force microscopy

    CERN Document Server

    Looi, L

    2002-01-01

    The interaction between a single polystyrene particle and a polystyrene substrate has been previously reported by a number of investigators. However, the effects of relative humidity, applied load and contact time on the adhesion of polystyrene surfaces have not been investigated and these effects are poorly understood. It is the primary aim of the current work to characterise the effect of the aforementioned parameters on the adhesion of polystyrene surfaces using atomic force microscopy. The polystyrene used in this study contained 1% of di-vinyl benzene as a cross-linking agent. From the work conducted using the custom-built instrument, the dependency of adhesion forces on the relative humidity is greatest at relative humidities above 60% where capillary forces cause a sharp increase in adhesion with increasing relative humidity. Hysteresis was observed in the solid-solid contact gradient of the accompanying force curves, suggesting non-elastic behaviour at the contact area of the surfaces

  16. Nanoencapsulation of Nimodipine in Novel Biocompatible Poly(propylene-co-butylene succinate Aliphatic Copolyesters for Sustained Release

    Directory of Open Access Journals (Sweden)

    Sofia Papadimitriou

    2009-01-01

    Full Text Available Biocompatible poly(propylene-co-butylene succinate (PPBSu copolyesters, containing up to 50 mol% butylene succinate units, were synthesized by the two-stage melt polycondensation method (esterification and polycondensation. The copolymers were fully characterized and biocompatibility studies were also performed. They were proved to be biocompatible and they were used as polymer matrices for the preparation of drug loaded nanoparticles. Nimodipine was selected as a model hydrophobic poorly water soluble drug. From the results obtained by dynamic light scattering (DLS and scanning electron microscopy (SEM, drug loaded copolymer nanoparticles were found to exhibit a spherical shape and their mean diameter appeared in the range of 180–200 nm. Fourier Transformation-Infrared Spectroscopy (FTIR spectra indicated that no chemical interaction between the drug and the matrix could be justified, while Wide-Angle X-Ray Diffraction (WAXD patterns proved a low degree of crystallinity of Nimodipine in the nanoparticles. The release behavior of the model drug from nanoparticles was also investigated in order to identify modifications and find out any possible correlation between the chemical composition of the polymer matrix and the drug release rates.

  17. O6-2'-Deoxyguanosine-butylene-O6-2'-deoxyguanosine DNA Interstrand Cross-Links Are Replication-Blocking and Mutagenic DNA Lesions.

    Science.gov (United States)

    Xu, Wenyan; Kool, Daniel; O'Flaherty, Derek K; Keating, Ashley M; Sacre, Lauralicia; Egli, Martin; Noronha, Anne; Wilds, Christopher J; Zhao, Linlin

    2016-11-21

    DNA interstrand cross-links (ICLs) are cytotoxic DNA lesions derived from reactions of DNA with a number of anti-cancer reagents as well as endogenous bifunctional electrophiles. Deciphering the DNA repair mechanisms of ICLs is important for understanding the toxicity of DNA cross-linking agents and for developing effective chemotherapies. Previous research has focused on ICLs cross-linked with the N7 and N2 atoms of guanine as well as those formed at the N6 atom of adenine; however, little is known about the mutagenicity of O 6 -dG-derived ICLs. Although less abundant, O 6 -alkylated guanine DNA lesions are chemically stable and highly mutagenic. Here, O 6 -2'-deoxyguanosine-butylene-O 6 -2'-deoxyguanosine (O 6 -dG-C4-O 6 -dG) is designed as a chemically stable ICL, which can be induced by the action of bifunctional alkylating agents. We investigate the DNA replication-blocking and mutagenic properties of O 6 -dG-C4-O 6 -dG ICLs during an important step in ICL repair, translesion DNA synthesis (TLS). The model replicative DNA polymerase (pol) Sulfolobus solfataricus P2 DNA polymerase B1 (Dpo1) is able to incorporate a correct nucleotide opposite the cross-linked template guanine of ICLs with low efficiency and fidelity but cannot extend beyond the ICLs. Translesion synthesis by human pol κ is completely inhibited by O 6 -dG-C4-O 6 -dG ICLs. Moderate bypass activities are observed for human pol η and S. solfataricus P2 DNA polymerase IV (Dpo4). Among the pols tested, pol η exhibits the highest bypass activity; however, 70% of the bypass products are mutagenic containing substitutions or deletions. The increase in the size of unhooked repair intermediates elevates the frequency of deletion mutation. Lastly, the importance of pol η in O 6 -dG-derived ICL bypass is demonstrated using whole cell extracts of Xeroderma pigmentosum variant patient cells and those complemented with pol η. Together, this study provides the first set of biochemical evidence for the

  18. Alternating polyesteramides based on 1,4-butylene terephthalamide: 3. alternating polyesteramides based on mixtures of, linear diols (4NTm,p)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Serrano, P.J.M.; van de Werff, B.A.; van der Werff, B.A.; Gaymans, R.J.

    1998-01-01

    Strictly alternating polyesteramides consisting of 1,4-butylene terephthalamide diester and mixtures of aliphatic diols have been synthesised in the melt in the presence of a titanium catalyst. To increase the molecular weight a solid state post condensation was applied. The composition was

  19. Poly(ethylene oxide)/poly(butylene terephthalate) segmented block copolymers: the effect of copolymer composition on physical properties and degradation behavior

    NARCIS (Netherlands)

    Deschamps, A.A.; Grijpma, Dirk W.; Feijen, Jan

    2001-01-01

    In this study, the influence of copolymer composition on the physical properties and the degradation behavior of thermoplastic elastomers based on poly(ethylene oxide) (PEO) and poly(butylene terephthalate) (PBT) segments is investigated. These materials are intended to be used in medical

  20. Effect of nanoclay on the nonisothermal crystallization of poly(propylene) and its blend with poly[(butylene succinate)-co-adipate

    CSIR Research Space (South Africa)

    Bandyopadhyay, J

    2012-05-01

    Full Text Available The non-isothermal crystallization behaviour and kinetics of neat poly(propylene)(PP), PP/poly[(butylene succinate)-co-adipate] (PP/PBSA) blend and its composite with nanoclay was studied by differential scanning calorimetry at six different cooling...

  1. Processing and characterization of recycled poly(ethylene terephthalate) blends with chain extenders, thermoplastic elastomer, and/or poly(butylene adipate-co-terephthalate)

    Science.gov (United States)

    Yottha Srithep; Alireza Javadi; Srikanth Pilla; Lih-Sheng Turng; Shaoqin Gong; Craig Clemons; Jun Peng

    2011-01-01

    Poly(ethylene terephthalate) (PET) resin is one of the most widely used thermoplastics, especially in packaging. Because thermal and hydrolytic degradations, recycled PET (RPET) exhibits poor mechanical properties and lacks moldability. The effects of adding elastomeric modifiers, chain extenders (CE), and poly(butylenes adipate-co-terephthalate), PBAT, as a toughener...

  2. Effects of chemical versus enzymatic processing of kenaf fibers on poly(hydroxybutyrate-co-valerate)/poly(butylene adipate-co-terephthalate) composite properties

    Science.gov (United States)

    The effect of fiber retting on crystallization and mechanical performance was investigated. A poly(hydroxybutyrate-co-valerate) (PHBV) and poly(butylene adipate-co-terephthalate) (PBAT) blend in a 80/20 ratio was modified using 5% by weight kenaf (Hibiscus cannabinus L.) fiber. Fibers were retted us...

  3. Thermal recycling of polystyrene and polystyrene-butadiene dissolved in a light cycle oil

    Energy Technology Data Exchange (ETDEWEB)

    Arandes, Jose M.; Erena, Javier; Olazar, Martin; Bilbao, Javier [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain); Azkoiti, Miren J. [Departamento de Ingenieria Quimica y del Medio Ambiente, Universidad del Pais Vasco, Plaza de la Casilla 3, 48012 Bilbao (Spain)

    2003-12-01

    A study has been made of the cracking on a mesoporous silica of polystyrene (PS) and polystyrene-butadiene (PS-BD) dissolved in a light cycle oil (LCO) from a product stream of a commercial fluid catalytic cracking (FCC) unit. This study has been carried out in a reactor of short contact time (3 s) in the 723-823 K range. This strategy for simultaneous valorization of plastics and solvent avoids the technological problems inherent to the treatment of solid postconsumer-plastics and the limitation to heat transfer in the process of pyrolysis. The cracking of plastics has a synergistic effect on the conversion of LCO, as it contributes to increasing the yield of gasoline (C{sub 5}-C{sub 12}). The cracking of the PS/LCO blend produces high yields of styrene, whereas the cracking of the PS-BD/LCO blend produces a stream of products with petrochemical interest.

  4. Phase Segregation in Polystyrene?Polylactide Blends

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Bonnie; Hitchcock, Adam; Brash, John; Scholl, Andreas; Doran, Andrew

    2010-06-09

    Spun-cast films of polystyrene (PS) blended with polylactide (PLA) were visualized and characterized using atomic force microscopy (AFM) and synchrotron-based X-ray photoemission electron microscopy (X-PEEM). The composition of the two polymers in these systems was determined by quantitative chemical analysis of near-edge X-ray absorption signals recorded with X-PEEM. The surface morphology depends on the ratio of the two components, the total polymer concentration, and the temperature of vacuum annealing. For most of the blends examined, PS is the continuous phase with PLA existing in discrete domains or segregated to the air?polymer interface. Phase segregation was improved with further annealing. A phase inversion occurred when films of a 40:60 PS:PLA blend (0.7 wt percent loading) were annealed above the glass transition temperature (Tg) of PLA.

  5. ANALYSIS DEGRADATION OF POLYSTYRENE WITH MONTMORILLONITE NANOFILLERS

    Directory of Open Access Journals (Sweden)

    Maria Mihalikova

    2014-01-01

    Full Text Available The paper is focused on the experimental investigation of the montmorillonite nanofillers effect on deformation properties of polystyrene KRASTEN 171. In some cases, combination of a low amount of clay with dispersed polymeric phase may cause synergistic effects leading to very fair balance of mechanical behaviour. This seems to be a consequence of complex influencing the multiphase system by clay such as modification of components (reinforcement and parameters of the interface accompanied by influencing the dynamic phase behaviour, i.e., the compactibilizing effect. The paper analyses the effect of nanocomposites and type of the material on the individual measured parameters, relations between them, strength and deformation behaviour. Deformation was evaluated by non-contact videoextensometry method

  6. Solvent selectivity studies using isomers of polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Men, L.C.; Na, H.; Rogers, L.B.

    1984-01-01

    The order of elution of isomeric trimers of polystyrene has been found to be independent of the dominant solvent-solute interaction as indicated by the location of the solvent in a Snyder triangle. The pure solvents were nitromethane, propylene carbonate, N-methylformamide, acetonitrile, the mixtures were trifluoroethanol with chloroform, methylene chloride and trichlorotrifluoroethane and also one of 2-methoxyethanol with water. Likewise, mixtures of acetonitrile with solvents near each of the corners of that triangle (chloroform, methylene chloride, and trifluoroethanol did not change the order of isomer elution). Substitution of trifluoroethanol for ethanol in mixtures with chloroform, methylene chloride, or trichlorotrifluoroethane led to improved isomer fractionations. 3 references, 5 figures, 2 tables.

  7. Correlated dewetting patterns in thin polystyrene films

    CERN Document Server

    Neto, C; Seemann, R; Blossey, R; Becker, J; Grün, G

    2003-01-01

    We describe preliminary results of experiments and simulations concerned with the dewetting of thin polystyrene films (thickness < 7 nm) on top of silicon oxide wafers. In the experiments we scratched an initially flat film with an atomic force microscopy (AFM) tip, producing dry channels in the film. Dewetting of the films was imaged in situ using AFM and a correlated pattern of holes ('satellite holes') was observed along the rims bordering the channels. The development of this complex film rupture process was simulated and the results of experiments and simulations are in good agreement. On the basis of these results, we attempt to explain the appearance of satellite holes and their positions relative to pre-existing holes.

  8. Resin Elongation Phenomenon of Polystyrene Nanopillars in Nanoimprint Lithography

    Science.gov (United States)

    Kuwabara, Kosuke; Miyauchi, Akihiro; Sugimura, Hiroyuki

    2010-10-01

    We investigated the elongation of polystyrene nanopillars formed by thermal nanoimprint lithography. Silicone and perfluoropolyether were used as mold release agents to obtain molds with different adhesion forces against polystyrene to be imprinted. The adhesion force between the resin and release layers was evaluated as a force curve by atomic force microscope with a polystyrene colloid probe. Elongation depended on the aspect ratio of the corresponding microholes on the mold and the adhesion force against the release layer. The conditions under which the elongation occurred exhibited a clear threshold on the stress loaded on the foot area of the nanopillars.

  9. Characterization of Pectin Nanocoatings at Polystyrene and Titanium Surfaces

    DEFF Research Database (Denmark)

    Gurzawska, Katarzyna; Dirscherl, Kai; Yihua, Yu

    2013-01-01

    study was to physically characterize and compare polystyrene and titanium surfaces nanocoated with different Rhamnogalacturonan-Is (RG-I) and to visualize RG-I nanocoatings. RG-Is from potato and apple were coated on aminated surfaces of polystyrene, titianium discs and titanium implants...... wettability, without any major effect on surface roughness (Sa, Sdr). Furthermore, we demonstrated that it is possible to visualize the pectin RG-Is molecules and even the nanocoatings on titanium surfaces, which have not been presented before. The comparison between polystyrene and titanium surface showed...

  10. Role of Acetone in the Formation of Highly Dispersed Cationic Polystyrene Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ernawati Lusi

    2017-03-01

    Full Text Available A modified emulsion polymerisation synthesis route for preparing highly dispersed cationic polystyrene (PS nanoparticles is reported. The combined use of 2,2′-azobis[2-(2-imidazolin- 2-ylpropane] di-hydrochloride (VA-044 as the initiator and acetone/water as the solvent medium afforded successful synthesis of cationic PS particles as small as 31 nm in diameter. A formation mechanism for the preparation of PS nanoparticles was proposed, whereby the occurrence of rapid acetone diffusion caused spontaneous rupture of emulsion droplets into smaller droplets. Additionally, acetone helped to reduce the surface tension and increase the solubility of styrene, thus inhibiting aggregation and coagulation among the particles. In contrast, VA-044 initiator could effectively regulate the stability of the PS nanoparticles including both the surface charge and size. Other reaction parameters i.e. VA-044 concentration and reaction time were examined to establish the optimum polymerisation conditions.

  11. Mortar modified with sulfonated polystyrene produced from waste plastic cups

    Directory of Open Access Journals (Sweden)

    L. A. C. MOTTA

    Full Text Available Abstract In this work, we studied the addition of sulfonated polystyrene produced from waste plastic cups as an admixture for mortars. Mortars were analyzed with polystyrene content of 0.0; 0.2; 0.6; 1.0 and 1.4% in relation to the cement mass. The influence of polystyrene on the mortars' properties was evaluated by the consistency index, water retention, water absorption, porosity, elasticity modulus, compressive strength, flexural strength, bond tensile strength and microscopy. The increase in the sulfonated polystyrene content decreased the elasticity modulus of the mortar and, despite higher porosity, there was a reduction of water absorption by capillarity. In relation to mortar without admixture, the modified mortar showed an increase in water retention and consistency index, and a large increase in flexural strength and bond tensile strength. The significant increase of bond tensile strength (214% with admixture 1% highlights the potential of the produced material as an adhesive mortar.

  12. Electro-Responsive Polystyrene Shape Memory Polymer Nanocomposites

    NARCIS (Netherlands)

    Xu, B.; Zhang, L.; Pei, Y.T.; Luo, J.K.; Tao, S.W.; Hosson, J.Th.M. De; Fu, Y.Q.

    Microstructure, thermo-mechanical, electrical properties and shape recovery efficiency of carbon nano-particles (CNPs) enhanced polystyrene (PS) nanocomposites were characterized. Dynamic mechanical thermal analysis showed an increase in glass transition temperature (T-g) and enhancement of the

  13. Adsorption of lysozyme unto silica and polystyrene surfaces in ...

    African Journals Online (AJOL)

    user

    2011-04-11

    , Nigeria. .... (mol L-1). Methods. The specific surface areas of the silica and polystyrene samples. (adsorbent) were determined using the method of adsorption of ... Alkaline copper reagents used for the quantification of the.

  14. Morphology, melting behavior, and non-isothermal crystallization of poly(butylene terephthalate)/poly(ethylene-co-methacrylic acid) blends

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.-W. [Department of Styling and Cosmetology, Tainan University of Technology, 529 Chung Cheng Rd., Yung Kang City 710, Taiwan (China)], E-mail: jw.huang@msa.hinet.net; Wen, Y.-L. [Department of Nursing, Meiho Institute of Technology, 23 Ping Kuang Rd., Neipu Hsiang, Pingtung 912, Taiwan (China); Department of Resources Engineering, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China); Kang, C.-C. [R and D Center, Hi-End Polymer Film Co., Ltd. 15-1 Sin Jhong Rd., Sin Ying City 730, Taiwan (China); Yeh, M.-Y. [Department of Chemistry, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China); Sustainable Environment Research Centre, National Cheng Kung University, Taiwan (China); Wen, S.-B. [Department of Nursing, Meiho Institute of Technology, 23 Ping Kuang Rd., Neipu Hsiang, Pingtung 912, Taiwan (China); Department of Resources Engineering, National Cheng Kung University, No. 1, University Rd., Tainan City 701, Taiwan (China)

    2007-12-15

    The morphology, melting behavior, and non-isothermal crystallization of poly(butylene terephthalate) (PBT) and poly(ethylene-co-methacrylic acid) (PEMA) blends were studied with scanning electron microscopy, X-ray diffraction and differential scanning calorimetry (DSC). PEMA forms immiscible, yet compatible, blends with PBT. Subsequent DSC scans on melt-crystallized samples exhibited two melting endotherms (T{sub mI} and T{sub mII}). The presence of PEMA would facilitate the recrystallization during heating scan and retard PBT molecular chains to form a perfect crystal in cooling crystallization. The dispersion phases of molten PEMA acts as nucleating agents to enhance the crystallization rate of PBT. The solidified PBT could act as nucleating agents to enhance the crystallization of PEMA, but also retard the molecular mobility to reduce crystallization rate. The U* and K{sub g} of Hoffman-Lauritzen theory were also determined by Vyazovkin's methods to support the interpretation.

  15. Delivery of paclitaxel using nanoparticles composed of poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO).

    Science.gov (United States)

    Wang, Lijiang; Yao, Ju; Zhang, Xiaomin; Zhang, Yingxin; Xu, Chang; Lee, Robert J; Yu, Gary; Yu, Bo; Teng, Lesheng

    2017-11-07

    An amphiphilic block copolymer poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) was evaluated as a carrier for therapeutic delivery of paclitaxel (PTX). PEO-PBO and PTX form nanoparticles (NPs) by self-assembly upon hydration. The size of these NPs was about 92.71nm and the zeta potential was -5.06mV, which met the requirements for passive tumor targeting through the enhanced permeability and retention effect. Compared with a commonly used block copolymer poly(ethylene glycol)-b-poly-D,L-(lactic acid) (PEG-PDLLA), PEO-PBO forms nanoparticles with superior pharmacokinetic, biodistribution, and tumor inhibitory properties. Meanwhile, results of hemolysis study and CMC determination showed that PEO-PBO had better biocompatibility and stability than PEG-PDLLA. These data suggest that PEO-PBO has potential for application in drug delivery and warrant further evaluation. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Nanoporous polystyrene fibers for oil spill cleanup.

    Science.gov (United States)

    Lin, Jinyou; Shang, Yanwei; Ding, Bin; Yang, Jianmao; Yu, Jianyong; Al-Deyab, Salem S

    2012-02-01

    The development of oil sorbents with high sorption capacity, low cost, scalable fabrication, and high selectivity is of great significance for water environmental protection, especially for oil spillage on seawater. In this work, we report nanoporous polystyrene (PS) fibers prepared via a one-step electrospinning process used as oil sorbents for oil spill cleanup. The oleophilic-hydrophobic PS oil sorbent with highly porous structures shows a motor oil sorption capacity of 113.87 g/g, approximately 3-4 times that of natural sorbents and nonwoven polypropylene fibrous mats. Additionally, the sorbents also exhibit a relatively high sorption capacity for edible oils, such as bean oil (111.80 g/g) and sunflower seed oil (96.89 g/g). The oil sorption mechanism of the PS sorbent and the sorption kinetics were investigated. Our nanoporous material has great potential for use in wastewater treatment, oil accident remediation and environmental protection. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Seismic Performance of Precast Polystyrene RC Walls

    Directory of Open Access Journals (Sweden)

    Wibowo Ari

    2017-01-01

    Full Text Available Precast concrete structure such as precast wall is a concept that is growing rapidly these days. However, the earthquake resistance is believed to be one of its drawbacks. Additionally, the large weight of solid elements also increase the building weight significantly which consequently increase the earthquake base shear force as well. Therefore, investigation on the seismic performance of precast concrete wall has been carried out. Three RC wall specimens using wire mesh reinforcement and EPS (Extended Polystyrene System panel have been tested. This wall was designed as a structural wall that was capable in sustaining lateral loads (in-plane yet were lightweight to reduce the total weight of the building. Parameter observed was the ratio of height to width (aspect ratio of wall of 1.0, 1.5 and 2.0 respectively with the aim to study the behaviour of brittle to ductile transition of the wall. Incremental static load tests were conducted until reaching peak load and then followed by displacement control until failure. Several data were measured at every stage of loading comprising lateral load-displacement behaviour, ultimate strength and collapse mechanism. The outcomes showed that precast concrete walls with a steel wire and EPS panel filler provided considerably good resistance against lateral load.

  18. Searching for new green wavelength shifters in polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Pla-Dalmau, A.; Foster, G.W.; Zhang, G.

    1993-12-01

    A series of commercially available fluorescent compounds was tested as wavelength shifters in polystyrene for the tile/fiber SDC calorimeter. The objective was to find a green-fluorescing compound with short decay time (3--7 ns). Transmittance, fluorescence, and decay time measurements were performed in order to characterize each compound in polystyrene. These samples were also studies for radiation-induced damage.

  19. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

    Science.gov (United States)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Mixed matrix membranes prepared from high impact polystyrene with dispersed TiO2 nanoparticles for gas separation

    Directory of Open Access Journals (Sweden)

    P. Safaei

    2016-01-01

    Full Text Available The current study presents synthesis and characterization of high impact polystyrene - TiO2 nanoparticles mixed matrix membranes for separation of carbon dioxide from nitrogen. The solution-casting method was used for preparation of membranes. The nano mixed matrix membranes were characterized using scanning electron microscopy to ensure the suitable dispersion of nano particles in high impact polystyrene matrix. The effect of TiO2 nanoparticles loading on membrane performance was investigated. The separation performance of synthesized membranes was investigated in separation of CO2 from CO2/N2 mixture. Effect of feed pressure and TiO2 content on separation of CO2 was studied. The results revealed that increase of feed pressure decreases flux of gases through the mixed matrix membrane. The results also confirmed that the best separation performance can be obtained at TiO2 nanoparticles loading of 7 wt.%.

  1. Polystyrene nanoparticles affect Xenopus laevis development

    Energy Technology Data Exchange (ETDEWEB)

    Tussellino, Margherita; Ronca, Raffaele [University of Naples Federico II, Department of Biology (Italy); Formiggini, Fabio [Italian Institute of Technology, Center for Advanced Biomaterials for Health Care IIT@CRIB (Italy); Marco, Nadia De [University of Naples Federico II, Department of Biology (Italy); Fusco, Sabato; Netti, Paolo Antonio [Italian Institute of Technology, Center for Advanced Biomaterials for Health Care IIT@CRIB (Italy); Carotenuto, Rosa, E-mail: rosa.carotenuto@unina.it [University of Naples Federico II, Department of Biology (Italy)

    2015-02-15

    Exposing living organisms to nanoparticulates is potentially hazardous, in particular when it takes place during embryogenesis. In this investigation, we have studied the effects of 50-nm-uncoated polystyrene nanoparticles (PSNPs) as a model to investigate the suitability of their possible future employments. We have used the standardized Frog Embryo Teratogenesis Assay-Xenopus test during the early stages of larval development of Xenopus laevis, and we have employed either contact exposure or microinjections. We found that the embryos mortality rate is dose dependent and that the survived embryos showed high percentage of malformations. They display disorders in pigmentation distribution, malformations of the head, gut and tail, edema in the anterior ventral region, and a shorter body length compared with sibling untreated embryos. Moreover, these embryos grow more slowly than the untreated embryos. Expressions of the mesoderm markers, bra (T-box Brachyury gene), myod1 (myogenic differentiation1), and of neural crest marker sox9 (sex SRY (determining region Y-box 9) transcription factor sox9), are modified. Confocal microscopy showed that the nanoparticles are localized in the cytoplasm, in the nucleus, and in the periphery of the digestive gut cells. Our data suggest that PSNPs are toxic and show a potential teratogenic effect for Xenopus larvae. We hypothesize that these effects may be due either to the amount of NPs that penetrate into the cells and/or to the “corona” effect caused by the interaction of PSNPs with cytoplasm components. The three endpoints of our study, i.e., mortality, malformations, and growth inhibition, suggest that the tests we used may be a powerful and flexible bioassay in evaluating pollutants in aquatic embryos.

  2. Precipitant induced porosity augmentation of polystyrene preserves the chondrogenicity of human chondrocytes.

    Science.gov (United States)

    Joergensen, Natasja L; Foldager, Casper B; Le, Dang Q S; Lind, Martin; Lysdahl, Helle

    2016-12-01

    Cells constantly sense and receive chemical and physical signals from neighboring cells, interstitial fluid, and extracellular matrix, which they integrate and translate into intracellular responses. Thus, the nature of the surface on which cells are cultured in vitro plays an important role for cell adhesion, proliferation, and differentiation. Autologs chondrocyte implantation is considered the treatment of choice for larger cartilage defects in the knee. To obtain a sufficient number of chondrocytes for implantation multiple passaging is often needed, which raises concerns about the changes in the chondrogenic phenotype. In the present study, we analyzed the effect at cellular and molecular level of precipitant induced porosity augmentation (PIPA) of polystyrene surfaces on proliferation and differentiation of human chondrocytes. Human chondrocytes were isolated from healthy patients undergoing anterior cruciate ligament reconstruction and cultured on PIPA modified polystyrene surfaces. Microscopical analysis revealed topographically arranged porosity with micron pores and nanometer pits. Chondrocytes cultured on PIPA surfaces revealed no difference in cell viability and proliferation, but gene- and protein expressions of collagen type II were pronounced in the first passage of chondrocytes when compared to chondrocytes cultured on control surfaces. Additionally, an analysis of 40 kinases revealed that chondrocytes expanded on PIPA caused upregulated PI3K/mTOR pathway activation and inhibition of mTORC1 resulted in reduced sGAG synthesis. These findings indicate that PIPA modified polystyrene preserved the chondrogenicity of expanded human chondrocytes at gene and protein levels, which clinically may be attractive for the next generation of cell-culture surfaces for ex vivo cell growth. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3073-3081, 2016. © 2016 Wiley Periodicals, Inc.

  3. Ionic liquids as surfactants for layered double hydroxide fillers: effect on the final properties of poly(butylene adipate-co-terephthalate)

    Czech Academy of Sciences Publication Activity Database

    Livi, S.; Lins, L. C.; Peter, Jakub; Beneš, Hynek; Kredatusová, Jana; Donato, R. K.; Pruvost, S.

    2017-01-01

    Roč. 7, č. 10 (2017), s. 1-16, č. článku 297. ISSN 2079-4991 R&D Projects: GA ČR(CZ) GA17-08273S Institutional support: RVO:61389013 Keywords : ionic liquids * poly(butylene adipate-co-terephthalate) * layered double hydroxide Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.553, year: 2016

  4. Magnetic properties of Fe-oxide and (Fe, Co) oxide nanoparticles synthesized in polystyrene resin matrix

    Science.gov (United States)

    Rodak, D.; Kroll, E.; Tsoi, G. M.; Vaishnava, P. P.; Naik, R.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Boolchand, P.

    2003-03-01

    Magnetic nanoparticles have potential applications ranging from drug delivery and imaging in the medical field to sensing and memory storage in technology. The preparation, structure, and physical properties of iron oxide-based nanoparticles synthesized by ion exchange in a polystyrene resin matrix have been investigated. Employing a synthesis method developed originally by Ziolo, et. al^1, nanoparticles were prepared in a sulfonated divinyl benzene polystyrene resin matrix using various aqueous solutions of (1) FeCl_2, (2) FeCl_3, (3) FeCl2 : 2FeCl3 , (4) 9FeCl2 : CoCl_2, and (5) 4FeCl2 : CoCl_2. Powder x-ray diffraction measurements were used to identify the phases present while transmission electron microscopy was used for particle size distribution determinations. SQUID magnetization measurements (field-cooled and zero-field-cooled) and Fe^57 Mössbauer effect measurements indicate the presence of ferromagnetic iron oxide phases and a superparamagnetic behavior with blocking temperatures (T_B) varying from 50 K to room temperature. Nanoparticles synthesized using a stoichiometric mixture of FeCl2 and FeCl3 exhibit the lowest TB and smallest particle size distribution. The Mössbauer effect measurements have also been used to identify the iron oxides phases present and their relative amounts in the nanoparticles ^1R.F. Ziolo, et al., Science 207, 219 (1992). *Permanent address: Kettering University, Flint, MI 48504

  5. Structure and Properties of Multiwall Carbon Nanotubes/Polystyrene Composites Prepared via Coagulation Precipitation Technique

    Directory of Open Access Journals (Sweden)

    I. N. Mazov

    2011-01-01

    Full Text Available Coagulation technique was applied for preparation of multiwall carbon nanotube- (MWNT-containing polystyrene (PSt composite materials with different MWNT loading (0.5–10 wt.%. Scanning and transmission electron microscopies were used for investigation of the morphology and structure of produced composites. It was shown that synthesis of MWNT/PSt composites using coagulation technique allows one to obtain high dispersion degree of MWNT in the polymer matrix. According to microscopy data, composite powder consists of the polystyrene matrix forming spherical particles with diameter ca. 100–200 nm, and the surface of MWNT is strongly wetted by the polymer forming thin layer with 5–10 nm thickness. Electrical conductivity of MWNT/PSt composites was investigated using a four-probe technique. Observed electrical percolation threshold of composite materials is near to 10 wt.%, mainly due to the insulating polymer layer deposited on the surface of nanotubes. Electromagnetic response of prepared materials was investigated in broadband region (0.01–4 and 26–36 GHz. It was found that MWNT/PSt composites are almost radiotransparent for low frequency region and possess high absorbance of EM radiation at higher frequencies.

  6. Use of Expanded Polystyrene (EPS and Shredded Waste Polystyrene (SWAP Beads for Control of Mosquitoes

    Directory of Open Access Journals (Sweden)

    A Soltani

    2008-12-01

    Full Text Available Background: Mosquitoes transmit several diseases to human. There are several measures for control of larvae. As part of Integrated Vector Management (IVM program, the utility of floating layers of polystyrene beads (EPS is a po­ten­tial alternative in habitats of mosquito larva. EPS beads prevent oviposition of mosquito as well as killing the im­ma­ture stages by forming a tick layer on the water surface.  They are cheap, environmentally safe and do not need fre­quent application and remain on the surface of water for long time. The objective of the current study was to asses the effectiveness of two types of polystyrene beads of (EPS and (SWAP for control of mosquito larvae under labo­ra­tory conditions.Methods: Anopheles stephensi and Culex quinquefasciatus were used for experimental purposes. In each tray 250 lar­vae of late 3rd and early 4th instars were introduced. The experiment was conducted on 4 replicates for An. ste­phensi, Cu. quinquefasciatus and combination of both. Emerging of adult mosquitoes were calculated every day until the end of experiments.Results: Mortality rate and Inhibition of Emerge (IE for Cu. quinquefasciatus, An. stephensi and combination of both spe­cies was 97.8%, 100% and 99.07%, respectively using EPS. In average, EPS was able to kill 98.9% of lar­vae. The fig­ures with SWAP were 63%, 91.05% and 72.65%, respectively. The average mortality for mosquitoes was 75.57%Conclusion: EPS and SWAP beads can be very effective and practical for elimination of An. stephensi and Cx. quinquefas­ciatus under the laboratory conditions.

  7. Production and characterization of novel starch and poly(butylene adipate-co-terephthalate)-based materials and their applications

    Science.gov (United States)

    Stagner, Jacqueline Ann

    This work focuses on the production and characterization of blends of maleated thermoplastic starch (MTPS) and poly(butylenes adipate-co-terephthalate) and their application for use as thermoformed objects, films, and foams. First, by the production and characterization of maleated thermoplastic starch (MTPS) synthesized by reactive extrusion in a twin-screw extruder, a better understanding of MTPS was gained. This reactive thermoplastic starch was prepared with glycerol as the plasticizer, maleic anhydride (MA), and free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Dynamic light scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), soxhlet extraction in acetone, and environmental scanning electron microscopy (ESEM) were performed to determine the effect of maleation, extrusion temperature, initiator concentration, and maleic anhydride concentration on the resulting MTPS. Next, maleated thermoplastic starch (MTPS) and thermoplastic starch (TPS) were reactively blended in a twin-screw extruder with a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT). The blends were extruded to produce thermoformable sheets. The mechanical properties of the sheets were characterized by tensile and puncture tests. Proof of grafting was determined by soxhlet extraction in dichloromethane and FTIR analysis. Observations of the thermal properties were made using DSC, while the surface of the sheets was imaged using ESEM. Blends of MTPS and PBAT were also extruded to produce films. Mechanical testing (tensile and puncture tests) and barrier performance testing (carbon dioxide, oxygen, and water vapor permeability) were performed on the films. Transmission electron microscopy (TEM) was used to image the blends and to view the dispersion of the various phases. Finally, blends of MTPS and PBAT were extruded with an endothermic chemical blowing agent to produce foams. The foams were

  8. Miscibility evolution of polycarbonate/polystyrene blends during compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib

    2002-01-01

    The miscibility evolution of polycarbonate/polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, remelt blending in a twin-screw extruder and third melt blending in an injection molding machine, was investigated by measu......The miscibility evolution of polycarbonate/polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, remelt blending in a twin-screw extruder and third melt blending in an injection molding machine, was investigated...

  9. Isothermal Gas assisted displacement of a polystyrene melt

    DEFF Research Database (Denmark)

    Eriksson, Torbjörn Gerhard; Rasmussen, Henrik K.

    2007-01-01

    Isothermal gas displacements of a polystyrene melt (shaped as circular cylinder with a radius of 2.5mm) placed inside a circular steel annulus were performed. A flow valve ensures a constant flow rate and rotational symmetric flow during the displacement. The experiments show an increase in the s......Isothermal gas displacements of a polystyrene melt (shaped as circular cylinder with a radius of 2.5mm) placed inside a circular steel annulus were performed. A flow valve ensures a constant flow rate and rotational symmetric flow during the displacement. The experiments show an increase...

  10. High electrokinetic energy conversion efficiency in charged nanoporous nitrocellulose/sulfonated polystyrene membranes.

    Science.gov (United States)

    Haldrup, Sofie; Catalano, Jacopo; Hansen, Michael Ryan; Wagner, Manfred; Jensen, Grethe Vestergaard; Pedersen, Jan Skov; Bentien, Anders

    2015-02-11

    The synthesis, characterization, and electrokinetic energy conversion performance have been investigated experimentally in a charged polymeric membrane based on a blend of nitrocellulose and sulfonated polystyrene. The membrane is characterized by a moderate ion exchange capacity and a relatively porous structure with average pore diameter of 11 nm. With electrokinetic energy conversion, pressure can be converted directly into electric energy and vice versa. From the electrokinetic transport properties, a remarkably large intrinsic maximum efficiency of 46% is found. It is anticipated that the results are an experimental verification of theoretical models that predict high electrokinetic energy conversion efficiency in pores with high permselectivity and hydrodynamic slip flow. Furthermore, the result is a promising step for obtaining efficient low-cost electrokinetic generators and pumps for small or microscale applications.

  11. Fabrication of Chitin/Poly(butylene succinate/Chondroitin Sulfate Nanoparticles Ternary Composite Hydrogel Scaffold for Skin Tissue Engineering

    Directory of Open Access Journals (Sweden)

    S. Deepthi

    2014-12-01

    Full Text Available Skin loss is one of the oldest and still not totally resolved problems in the medical field. Since spontaneous healing of the dermal defects would not occur, the regeneration of full thickness of skin requires skin substitutes. Tissue engineering constructs would provide a three dimensional matrix for the reconstruction of skin tissue and the repair of damage. The aim of the present work is to develop a chitin based scaffold, by blending it with poly(butylene succinate (PBS, an aliphatic, biodegradable and biocompatible synthetic polymer with excellent mechanical properties. The presence of chondroitin sulfate nanoparticles (CSnp in the scaffold would favor cell adhesion. A chitin/PBS/CSnp composite hydrogel scaffold was developed and characterized by SEM (Scanning Electron Microscope, FTIR (Fourier Transform Infrared Spectroscopy, and swelling ratio of scaffolds were analyzed. The scaffolds were evaluated for the suitability for skin tissue engineering application by cytotoxicity, cell attachment, and cell proliferation studies using human dermal fibroblasts (HDF. The cytotoxicity and cell proliferation studies using HDF confirm the suitability of the scaffold for skin regeneration. In short, these results show promising applicability of the developed chitin/PBS/CSnps ternary composite hydrogel scaffolds for skin tissue regeneration.

  12. Effect of dissolved oxygen on heterotrophic denitrification using poly(butylene succinate) as the carbon source and biofilm carrier.

    Science.gov (United States)

    Luo, Guozhi; Li, Li; Liu, Qian; Xu, Guimei; Tan, Hongxin

    2014-11-01

    The effect of dissolved oxygen (DO) on heterotrophic denitrification using poly(butylene succinate) as the carbon source and biofilm carrier was evaluated in a lab-scale experiment. Aerated, low-oxygen, and anoxic treatment groups were set up, which had average DO concentrations of 5.2±1.0, 1.4±1.2, and 0.5±0.3 mg L(-1), respectively. The NO3(-)-N and total nitrogen (TN) removal rates in the aerated group (37.44±0.24 and 36.24±0.48 g m(-3) d(-1), respectively) were higher than those in the other two groups. There was no significant difference between the low-oxygen and anoxic groups for the NO3(-)-N or TN removal rate. Accumulation of NO2(-)-N reached 5.0 mg L(-1) in the aerated group; no nitrite accumulation was found in the other two treatment groups. Bacterial communities of the low-oxygen and anoxic groups showed high similarity and were significantly different from those of the aerated group. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Biological denitrification using poly(butylene succinate) as carbon source and biofilm carrier for recirculating aquaculture system effluent treatment.

    Science.gov (United States)

    Zhu, Song-Ming; Deng, Ya-Le; Ruan, Yun-Jie; Guo, Xi-Shan; Shi, Ming-Ming; Shen, Jia-Zheng

    2015-09-01

    Nitrate removal is essential for the sustainable operation of recirculating aquaculture system (RAS). This study evaluated the heterotrophic denitrification using poly(butylene succinate) as carbon source and biofilm carrier for RAS wastewater treatment. The effect of varied operational conditions (influent type, salinity and nitrate loading) on reactor performance and microbial community was investigated. The high denitrification rates of 0.53 ± 0.19 kg NO3(-)-N m(-3) d(-1) (salinity, 0‰) and 0.66 ± 0.12 kg NO3(-)-Nm(-3) d(-1) (salinity, 25‰) were achieved, and nitrite concentration was maintained below 1mg/L. In addition, the existence of salinity exhibited more stable nitrate removal efficiency, but caused adverse effects such as excessive effluent dissolved organic carbon (DOC) and dissimilation nitrate reduce to ammonia (DNRA) activity. The degradation of PBS was further confirmed by SEM and FTIR analysis. Illumina sequencing revealed the abundance and species changes of functional denitrification and degradation microflora which might be the primary cause of varied reactor performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Poly(butylene 2,5-thiophenedicarboxylate: An Added Value to the Class of High Gas Barrier Biopolyesters

    Directory of Open Access Journals (Sweden)

    Giulia Guidotti

    2018-02-01

    Full Text Available Many efforts are currently devoted to the design and development of high performance bioplastics to replace traditional fossil-based polymers. In response, this contribution presents a new biobased aromatic polyester, i.e., poly(butylene 2,5-thiophenedicarboxylate (PBTF. Here, PBTF is characterized from the molecular, thermo-mechanical and structural point of view. Gas permeability is evaluated at different temperatures, in the range below and above glass transition, providing a full insight into the performances of this material under different operating conditions, and demonstrating the superior gas barrier behavior of PBTF with respect to other polyesters, such as PEF and PET. The combination of calorimetric and diffractometric studies allows for a deep understanding of the structure of PBTF, revealing the presence of a not-induced 2D-ordered phase (meso-phase, responsible for its outstanding gas permeability behavior. The simple synthetic strategy adopted, the exceptional barrier properties, combined with the interesting mechanical characteristics of PBTF open up new scenarios in the world of green and sustainable packaging materials.

  15. Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization.

    Science.gov (United States)

    Ojijo, Vincent; Ray, Suprakas Sinha; Sadiku, Rotimi

    2013-05-22

    Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m(2) for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.

  16. Hybrids of HNBR and in situ polymerizable cyclic butylene terephthalate (CBT oligomers: properties and dry sliding behavior

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available A peroxide curable hydrogenated nitrile rubber (HNBR was modified by cyclic butylene terephthalate oligomer (CBT, added in 100 parts per hundred rubber (phr. CBT polymerization was expected to occur simultaneously with that of the curing of the HNBR rubber (T = 190°C, t = 25 min. Differential scanning calorimetry (DSC indicated that only a minor part of CBT has been polymerized (pCBT in the hybrid. Dynamic mechanical thermal analysis (DMTA revealed that HNBR formed the continuous whereas (pCBT the dispersed phase. Mechanical properties (hardness, tensile modulus, ultimate tensile strength and strain, tear strength of the HNBR and HNBR/CBT were determined and collated. Tribological properties were investigated with pin(steel-onplate(rubber (POP, with roller(steel-on-plate (rubber (ROP, with oscillating steel cylinder on rubber plate (Fretting test configurations. Coefficient of friction (COF and specific wear rate of the HNBR-based systems were determined. It was found that the resistance to wear increases with CBT hybridization. On the other hand, COF did not change much with CBT content. The friction and wear characteristics strongly depended on the test configurations. The worn surface of the HNBR systems was inspected in scanning electron microscope (SEM to conclude the typical wear mechanisms. SEM investigation showed that the CBT was predominantly recrystallized from its molten state under the curing conditions set. The well developed prism- and platy-like, micron-scaled CBT crystals were made responsible for the reinforcing effect observed.

  17. Phase Morphology and Mechanical Properties of Cyclic Butylene Terephthalate Oligomer-Containing Rubbers: Effect of Mixing Temperature

    Directory of Open Access Journals (Sweden)

    István Zoltán Halász

    2016-08-01

    Full Text Available In this work, the effect of mixing temperature (Tmix on the mechanical, rheological, and morphological properties of rubber/cyclic butylene terephthalate (CBT oligomer compounds was studied. Apolar (styrene butadiene rubber, SBR and polar (acrylonitrile butadiene rubber, NBR rubbers were modified by CBT (20 phr for reinforcement and viscosity reduction. The mechanical properties were determined in tensile, tear, and dynamical mechanical analysis (DMTA tests. The CBT-caused viscosity changes were assessed by parallel-plate rheometry. The morphology was studied by scanning electron microscopy (SEM. CBT became better dispersed in the rubber matrices with elevated mixing temperatures (at which CBT was in partially molten state, which resulted in improved tensile properties. With increasing mixing temperature the size of the CBT particles in the compounds decreased significantly, from few hundred microns to 5–10 microns. Compounding at temperatures above 120 °C and 140 °C for NBR and SBR, respectively, yielded reduced tensile mechanical properties most likely due to the degradation of the base rubber. The viscosity reduction by CBT was more pronounced in mixes with coarser CBT dispersions prepared at lower mixing temperatures.

  18. The influence of manganese-cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate).

    Science.gov (United States)

    Wang, Dong; Zhang, Qiangjun; Zhou, Keqing; Yang, Wei; Hu, Yuan; Gong, Xinglong

    2014-08-15

    By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co3O4) nano-particles, manganese-cobalt oxide/graphene hybrids (MnCo2O4-GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo2O4-GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo2O4-GNS/PBT composites were lower than that of pure PBT and Co3O4-GNS/PBT composites. Furthermore, the incorporation of MnCo2O4-GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O4 for organic volatiles and carbon monoxide. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Solution viscosity – molar mass relationships for poly(butylene succinate and discussion on molar mass analysis

    Directory of Open Access Journals (Sweden)

    Q. Charlier

    2015-05-01

    Full Text Available Poly(butylene succinate (PBS is currently developing due to its biodegradability and the similarity of its mechanical properties to those of polyolefins. Relationships between the number average molar mass, Mn, and solution viscosity such as [η] and ηred were derived for this aliphatic polyester. Mn values were determined by end-group analysis and size exclusion chromatography (SEC. Mark-Houwink-Sakurada (MHS parameters were proposed in two solvents and for the different molar masses and viscosity measurement methods. As an example, the MHS equations were respectively, [η] =6.4•10–4•Mn0.67 in chloroform and [η] = 7.1•10–4•Mn0.69 in 50/50 wt% 1,2-dichlorobenzene/phenol at 25°C for molar masses measured by SEC in hexafluoro isopropanol (HFIP with poly(methyl methacrylate (PMMA standards. Empirical relationships were also suggested to derive Mn directly from reduced viscosity, ηred, which is much easier to determine than intrinsic viscosity. With these data, the number average molar mass of PBS can be conveniently estimated from a single viscosity measurement. In addition, it was shown that PBS contains 1–2 wt% of cyclic oligomers produced during esterification and that molar masses determined by taking this fraction into account or not were significantly different, especially for long chains.

  20. Preparation of surface-modified poly(butylene terephthalate) nonwovens and their application as leukocyte removal filters.

    Science.gov (United States)

    Kim, Eun Jin; Yeo, Gwu-Dong; Pai, Chaul-Min; Kang, Inn-Kyu

    2009-08-01

    Blood transfusion-related adverse reactions have been reported to be caused by leukocytes in blood products. It is now generally accepted that it would be highly desirable to reduce leukocytes level as low as possible. In this study, melt-blown poly(butylene terephthalate) nonwoven (PBT-NW) was treated with a hydroxyapatite (HA) surface-modification method for removal of leukocytes from blood components. Acrylic acid was graft-polymerized onto the surface of the PBT-NW after oxygen plasma glow discharge treatment. The PBT-NW surface was covered with a thin layer of HA produced by immersing the polymer surface in an aqueous solution containing high concentrations of PO(4) (3-) and Ca(2+) after graft-polymerization of acrylic acid, which provided the nucleus for HA crystallization. The surface was characterized using water contact angles, attenuated total reflection-Fourier transform infrared (ATR-FT-IR), and electron spectroscopy for chemical analysis. When filtration was performed with a unit of red blood cell concentrates, HA-deposited PBT-NW (PBT-HA) removed 98.5% of the leukocytes and recovered 99.5% of the erythrocytes, suggesting that HA-deposited PBT-NW is a very promising blood filter for selective removal of leukocytes.

  1. Syntheses, magnetic and spectral studies on polystyrene supported ...

    Indian Academy of Sciences (India)

    ... and triethylamine (TEA) produces another polystyrene-anchored dibasic tetradentate Schiff base, PSCH2-L'H2 (II). Both I and II react with a number of di-, tri- and hexavalent metal ions like Co, Ni, Cu, Zn and Cd to form polystyreneanchored coordination compounds, and these have been characterized and discussed.

  2. Nanocomposite of polystyrene foil grafted with metallaboranes for antimicrobial activity

    Czech Academy of Sciences Publication Activity Database

    Benkocká, M.; Kolářová, K.; Matoušek, J.; Semerádtová, A.; Šícha, Václav; Kolská, Z.

    2018-01-01

    Roč. 441, MAY (2018), s. 120-129 ISSN 0169-4332 R&D Projects: GA MŠk(CZ) LM2015073 Institutional support: RVO:61388980 Keywords : Antimicrobial activity * Chemical grafting * Metallaboranes * Piranha solution * Polystyrene * Surface properties Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 3.387, year: 2016

  3. Morphology Evolution of Polycarbonate-Polystyrene Blends During Compounding

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, Kristoffer; Johannsen, Ib

    2001-01-01

    The morphology evolution of polycarbonate-polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, re-melt blending in a twin-screw extruder and tri-melt blending in an injection-moulding machine, was investigated using...

  4. Fabrication of Cationic Exchange Polystyrene Nanofibers for Drug ...

    African Journals Online (AJOL)

    Purpose: To prepare polystyrene nanofiber ion exchangers (PSNIE) with surface cation exchange functionality using a new method based on electrospinning and also to optimize crosslinking and sulfonation reactions to obtain PSNIE with maximum ion exchange capacity (IEC). Method: The nanofibers were prepared from ...

  5. Woodpecker Excavation and Use of Cavities in Polystyrene Snags

    Science.gov (United States)

    Richard N. Conner; Daniel Saenz

    1996-01-01

    We examined woodpecker excavation and use of artificial polystyrene snags in four forest types in eastern Texas for five years. Twenty-three of 47 artificial snags were used by Downy Woodpeckers (Picoides pubescens) for cavity excavation and subsequent nocturnal roosting; they did not use the artificial snags for nesting. Although six ather species of woodpeckers...

  6. Fabrication of Cationic Exchange Polystyrene Nanofibers for Drug ...

    African Journals Online (AJOL)

    Method: The nanofibers were prepared from 15% w/v polystyrene solution in dimethylacetamide (DMAc) containing 0.025 %w/v tetrabutylammonium bromide (TBAB) using electrospinning technique, followed by crosslinking with sulfuric acid/formaldehyde in a ratio ranging from 100/0 to 50/50 v/v and sulfonation in sulfuric ...

  7. Preparation of Electrically Conductive Polystyrene/Carbon Nanofiber Nanocomposite Films

    Science.gov (United States)

    Sun, Luyi; O'Reilly, Jonathan Y.; Tien, Chi-Wei; Sue, Hung-Jue

    2008-01-01

    A simple and effective approach to prepare conductive polystyrene/carbon nanofiber (PS/CNF) nanocomposite films via a solution dispersion method is presented. Inexpensive CNF, which has a structure similar to multi-walled carbon nanotubes, is chosen as a nanofiller in this experiment to achieve conductivity in PS films. A good dispersion is…

  8. Heavy metal ion uptake properties of polystyrene-supported ...

    Indian Academy of Sciences (India)

    Metal ion uptake properties of polystyrene-supported chelating polymer resins functionalized with (i) glycine, (ii) hydroxy benzoic acid, (iii) Schiff base and (iv) diethanol amine have been investigated. The effects of pH, time and initial concentration on the uptake of metal ions have been studied. The uptake of metal ion ...

  9. Polystyrene as a zwitter resist in electron beam lithography based ...

    Indian Academy of Sciences (India)

    The resist action of polystyrene (w, 2,600,000) towards electroless deposition of gold on Si(100) surface following cross-linking by exposing to a 10 kV electron beam, has been investigated employing a scanning electron microscope equipped with electron beam lithography tool. With a low dose of electrons (21 C/cm2), ...

  10. production of particleboards using polystyrene and bamboo wastes

    African Journals Online (AJOL)

    HOD

    PRODUCTION OF PARTICLEBOARDS USING POLYSTYRENE AND BAMBOO WASTES. S. A. Abdulkareem & A. G. Adeniyi. Nigerian Journal of Technology. Vol. 36, No. 3, July 2017 793. Properties of resin bonded particleboards; Maderas. Ciencia y Tecnología,:13(1) 49-58, 2011. [13] Laemsak, N., & Kungsuwan, ...

  11. Rheological Behavior of Entangled Polystyrene-Polyhedral Oligosilsesquioxane (POSS) Copolymer

    National Research Council Canada - National Science Library

    Wu, Jian; Mather, Patrick T; Haddad, Timothy S; Kim, Gyeong-Man

    2006-01-01

    ...: random copolymers of polystyrene (PS) and styryl-based polyhedral oligosilsesquioxane (POSS), R7(Si8O12)(C6H4CH=CH2), with R = isobutyl (iBu). A series of styrene-styryl POSS random copolymers with 0, 6, 15, 30, 50 wt...

  12. The Swelling Behaviour of Polystyrene (PS)/ Polyvinylacetate (Pvac ...

    African Journals Online (AJOL)

    The effect of the variation of the type of solvent responsible for the differences in the swelling kinetics of Polystyrene (PS) and Polyvinyl acetate (PVAc) blends was studied. The results showed that the nature of solvent control or affects the degree of swelling. Also, 1-V characteristics at temperature range of 323-363K shows ...

  13. Polystyrene-Al2O3 composite solid polymer electrolyte for lithium secondary battery.

    Science.gov (United States)

    Lim, Yu-Jeong; An, Yu-Ha; Jo, Nam-Ju

    2012-01-05

    In a common salt-in-polymer electrolyte, a polymer which has polar groups in the molecular chain is necessary because the polar groups dissolve lithium salt and coordinate cations. Based on the above point of view, polystyrene [PS] that has nonpolar groups is not suitable for the polymer matrix. However, in this PS-based composite polymer-in-salt system, the transport of cations is not by segmental motion but by ion-hopping through a lithium percolation path made of high content lithium salt. Moreover, Al2O3 can dissolve salt, instead of polar groups of polymer matrix, by the Lewis acid-base interactions between the surface group of Al2O3 and salt. Notably, the maximum enhancement of ionic conductivity is found in acidic Al2O3 compared with neutral and basic Al2O3 arising from the increase of free ion fraction by dissociation of salt. It was revealed that PS-Al2O3 composite solid polymer electrolyte containing 70 wt.% salt and 10 wt.% acidic Al2O3 showed the highest ionic conductivity of 9.78 × 10-5 Scm-1 at room temperature.

  14. Synthesis of thermoplastic poly(ester-olefin elastomers

    Directory of Open Access Journals (Sweden)

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  15. Síntese e caracterização de Nanocompósitos Esfoliados de Poliestireno: Hidróxido Duplo Lamelar via polimerização in situ Synthesis and characterization of Exfoliated Polystyrene: Layered Double Hydroxide Nanocomposites via in situ polymerization

    Directory of Open Access Journals (Sweden)

    Rodrigo Botan

    2011-01-01

    Full Text Available Nanocompósitos Esfoliados de Poliestireno (PS e Hidróxido Duplo Lamelar (HDL composto por zinco, alumínio e dodecil sulfato de sódio, como ânion interlamelar, foram sintetizados via polimerização in situ. O efeito de diferentes composições de HDL (0,5, 1, 3 e 5% em massa foi avaliado. Os nanocompósitos obtidos foram caracterizados através de ensaios de Difração de Raios X (DRX, Espectroscopia no Infravermelho por Transformada de Fourier (FTIR, Microscopia Eletrônica de Transmissão (MET e Análise Termogravimétrica (TGA. Os resultados obtidos através das análises de DRX e MET mostraram que todos os nanocompósitos produzidos apresentaram morfologia esfoliada. Os resultados das TGA, quando se utilizam 50% de perda de peso como ponto para comparação, apresentaram ganhos significativos de estabilidade térmica para todas as composições dos nanocompósitos em comparação ao poliestireno puro. Este comportamento possibilita uma vasta gama de aplicação destes novos materiais em diversos campos da indústria e pesquisa.Exfoliated nanocomposites of polystyrene (PS and layered double hydroxide (LDH compound of zinc, aluminium and sodium dodecyl sulfate, as interlayer anion, have been synthesized via in situ polymerization. The effect from the LDH compositions (0.5, 1, 3, 5% weight was studied. The nanocomposites were characterized by X-ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR, Transmission Electron Microscopy (TEM and Thermogravimetric Analysis (TGA. The XRD and TEM results showed an exfoliated morphology for the nanocomposites in all compositions. With the 50% weight loss taken as a reference, the TGA results indicated significant improvement in thermal stability for all compositions of the nanocomposites, in comparison to pure polystyrene. This is promising for the application of these new materials in many fields of industry and research.

  16. Concurrent Enhancement of Multiple Properties in Reactively Processed Nanocomposites of Polylactide/Poly[(butylene succinate)-co-adipate] Blend and Organoclay

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2014-05-01

    Full Text Available stream_source_info Ojijo2_2014_ABSTRACT ONLY.pdf.txt stream_content_type text/plain stream_size 1813 Content-Encoding UTF-8 stream_name Ojijo2_2014_ABSTRACT ONLY.pdf.txt Content-Type text/plain; charset=UTF-8... Macromolecular Materials and Engineering Vol. 299(5), pp 596- 608 Concurrent Enhancement of Multiple Properties in Reactively Processed Nanocomposites of Polylactide/Poly[(butylene succinate)-co-adipate] Blend and Organoclaya Vincent Ojijo, Suprakas Sinha...

  17. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  18. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    Science.gov (United States)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

  19. Reinforcement effect of poly(butylene succinate) (PBS)-grafted cellulose nanocrystal on toughened PBS/polylactic acid blends.

    Science.gov (United States)

    Zhang, Xuzhen; Zhang, Yong

    2016-04-20

    Poly(butylene succinate) (PBS)/polylactic acid (PLA) blends modified with dicumyl peroxide (DCP) were reinforced by PBS-g-cellulose nanocrystal (CNC) through melt mixing. PBS-g-CNC was prepared through in situ polymerization and its structure was confirmed by FTIR, (13)C NMR, XPS and GPC analysis after saponification. The morphological analysis of PBS/PLA/PBS-g-CNC composites before and after etched by CH2Cl2 shows that the addition of DCP and PBS-g-CNC could decrease the size of PBS as a dispersed phase in PLA matrix and improve the dispersion of PBS-g-CNC in both PBS and PLA phases, which could affect the crystallization and mechanical properties of composites. The crystallinity of PLA α'-phase crystal in PBS/PLA/PBS-g-CNC composites is increased obviously by the addition of PBS-g-CNC, leading to an increase of the crystallinity of the composites. PBS/PLA blends modified by DCP have high Notched Izod impact strength and moduli, and the values are increased by the addition of PBS-g-CNC. Both storage modulus and glass translation temperature of PBS/PLA blend are increased by DCP and PBS-g-CNC, which is proved by DMA results, showing a weak molecular segment mobility of PBS/PLA matrix. The addition of DCP decreases the crystallization temperature and crystallinity of PBS/PLA composite, but increases the thermal stability of composites, mostly because of the crosslink effect of DCP on PBS/PLA matrix. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Toughening modification of poly(butylene terephthalate)/poly(ethylene terephthalate) blends by an epoxy-functionalized elastomer

    Science.gov (United States)

    Zhang, Weizhou; Wang, Kai; Yan, Wei; Guo, Weihong

    2017-10-01

    New toughened poly(butylene terephthalate) (PBT)/poly(ethylene terephthalate) (PET) (40/60 wt%) blends were obtained by melting with Glycidyl methacrylate grafted poly(ethylene octane) copolymer (POE-g-GMA), varying the POE-g-GMA content up to 20 wt%, in a twin-screw extruder, followed by injection molding. The influence of POE-g-GMA on the properties of the PBT/PET blends was investigated by mechanical testing, Fourier transform infrared (FT-IR) analysis, gel fractions analysis, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM). The mechanical testing results indicated that the incorporation of POE-g-GMA led to increases in the notched impact strength and decreases in the tensile strength, flexural strength, and flexural modulus. When POE-g-GMA content reached 20 wt%, the notched impact strength (8.0 kJ m‑2) was achieved for the PBT/PET/POE-g-GMA blends. FT-IR results proved that some PBT/PET/POE-g-GMA copolymers were produced, which improved the compatibility between POE-g-GMA and the PBT/PET matrix. The extent of crosslinking was observed by gel fraction measurements. DMA results further testified chain-extending and micro-crosslink reactions occurred between POE-g-GMA and PBT/PET blends. In addition, the reactions induced by POE-g-GMA affected the crystallization behavior of PBT/PET blends obviously, as observed from DSC results. By means of SEM observation of the impact fracture surface morphology, and the discussion of the micro-crosslink reaction process between the epoxide-containing elastomers and PBT/PET matrix, the toughening mechanism was proposed to be taken into account the shear yielding of PBT/PET matrix and cavitation of elastomer particles.

  1. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Llorens, E.; Ibañez, H. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Valle, L.J. del, E-mail: luis.javier.del.valle@upc.edu [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Center for Research in Nano-Engineering (CrNE), Universitat Politècnica de Catalunya, Edifici C, C/Pasqual i Vila s/n, Barcelona E-08028 (Spain)

    2015-04-01

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  2. Cellular Concrete Bricks with Recycled Expanded Polystyrene Aggregate

    Directory of Open Access Journals (Sweden)

    Juan Bosco Hernández-Zaragoza

    2013-01-01

    Full Text Available Cellular concrete bricks were obtained by using a lightweight mortar with recycled expanded polystyrene aggregate instead of sandy materials. After determining the block properties (absorption, compressive strength, and tensile stresses, it was found that this brick meets the requirements of the masonry standards used in Mexico. The obtained material is lighter than the commercial ones, which facilitates their rapid elaboration, quality control, and transportation. It is less permeable, which helps prevent moisture formation retaining its strength due to the greater adherence shown with dry polystyrene. It was more flexible, which makes it less vulnerable to cracking walls due to soil displacements. Furthermore, it is economical, because it uses recyclable material and has properties that prevent deterioration increasing its useful life. We recommend the use of the fully dry EP under a dry environment to obtain the best properties of brick.

  3. Hypernatremia in a patient treated with sodium polystyrene sulfonate

    Directory of Open Access Journals (Sweden)

    Manish Nepal

    2010-11-01

    Full Text Available Manish Nepal, Ion Dan Bucaloiu, Evan R NorfolkGeisinger Medical Center, Department of Nephrology, Danville, PA, USAAbstract: Severe hyperkalemia requires urgent medical attention and correction in order to prevent arrhythmic complications. Sodium polystyrene sulfonate (SPS is a cation exchange resin commonly used in the management of hyperkalemia. A recent review raised concerns regarding its effectiveness and potential adverse effects. Hypernatremia in adults in the setting of sodium polystyrene sulfonate therapy has not been described in the literature. We report the case of a woman who developed hypernatremia in the setting of excessive SPS administration and hope to increase awareness among clinicians regarding this potential side effect of SPS therapy.Keywords: SPS, hyperkalemia 

  4. Insulation materials. Cellulose fiber and Expanded polystyrene Insulations

    OpenAIRE

    Viladot Bel, Cèlia

    2017-01-01

    The main role of thermal insulation materials in a building envelope are to prevent heat loss and provide thermal comfort for a building's interior. The factor that characterizes an insulation material's effectiveness is its thermal conductivity λ (measured in W/mK). The lower a material's thermal conductivity, the more effective it is as an insulator. Traditional insulation materials include glass fibre, stone wool, expanded polystyrene, and polyurethane foam. While these materials are effic...

  5. Insulation materials. Cellulose fiber and expanded polystyrene insulations

    OpenAIRE

    Viladot Bel, Cèlia

    2017-01-01

    The main role of thermal insulation materials in a building envelope are to prevent heat loss and provide thermal comfort for a building's interior. The factor that characterizes an insulation material's effectiveness is its thermal conductivity λ (measured in W/mK). The lower a material's thermal conductivity, the more effective it is as an insulator. Traditional insulation materials include glass fibre, stone wool, expanded polystyrene, and polyurethane foam. While these materials are effic...

  6. Syntheses, magnetic and spectral studies on polystyrene supported ...

    Indian Academy of Sciences (India)

    Unknown

    salicylic acid occurs at 1660 cm–1. The appearance of a new band at 1730 cm–1 due to ν(C=O) (ester) in. PSCH2–L′H2 confirms the covalent bond formation via the ester linkage15 between L′H3 and PSCH2–Cl. This band remains unchanged in the polystyrene- anchored coordination compounds, indicating the.

  7. Preparation and Properties of Branched Polystyrene through Radical Suspension Polymerization

    Directory of Open Access Journals (Sweden)

    Wenyan Huang

    2017-01-01

    Full Text Available Radical solvent-free suspension polymerization of styrene with 3-mercapto hexyl-methacrylate (MHM as the branching monomer has been carried out using 2,2′-azobisisobutyronitrile (AIBN as the initiator to prepare branched polymer beads of high purity. The molecular weight and branching structure of the polymers have been characterized by triple detection size exclusion chromatography (TD-SEC, proton nuclear magnetic resonance spectroscopy (1H-NMR, and Fourier transform infrared spectroscopy (FTIR. The glass transition temperature and rheological properties have been measured by using differential scanning calorimetry (DSC and rotational rheometry. At mole ratios of MHM to AIBN less than 1.0, gelation was successfully avoided and branched polystyrene beads were prepared in the absence of any solvent. Branched polystyrene has a relatively higher molecular weight and narrower polydispersity (Mw.MALLS = 1,036,000 g·mol−1, Mw/Mn = 7.76 than those obtained in solution polymerization. Compared with their linear analogues, lower glass transition temperature and decreased chain entanglement were observed in the presently obtained branched polystyrene because of the effects of branching.

  8. The influence of antioxidant and post-synthetic treatment on the properties of biodegradable poly(butylene succinates modified with poly(propylene oxide

    Directory of Open Access Journals (Sweden)

    DRAGANA PEPIC

    2007-12-01

    Full Text Available Novel poly(ester–ethers based on poly(butylene succinate (PBS as the hard segments and 30 mass % of poly(propylene oxide (PPO as the soft segments were synthesized with varying amount of the antioxidant (N,N'-diphenyl-p-phenylenediamine, DPPD. The influences of the addition of DPPD and the impact of post-synthetic treatment by precipitation on the molecular structure, thermal and physical properties, as well as on the storage stability of the biodegradable aliphatic copolyesters, were investigated. The structure and composition of the copolymers were determined by means of 1H-NMR spectroscopy. The molecular weight and polydispersity of the poly(ester–ethers were evaluated from solution viscosity and GPC measurements. The thermal properties and stability were evaluated, respecttively, by means of DSC and non-isothermal thermogravimetry in an inert nitrogen atmosphere. The biodegradability potential of the polymers was studied in hydrolytic and enzymatic degradation tests with Candida cylindracea lipase by monitoring the weight loss of polymer films after incubation. The weight losses of the samples increased with time and were in the range from 1 to 5 mass % after 4 weeks. GPC analysis confirmed that there were changes in the molecular weight of the copolyesters during both hydrolytic and enzymatic degradation tests, leading to the conclusion that the degradation mechanism of poly(butylenes succinate modified with PPO occurred through surface erosion and bulk degradation.

  9. Poly(butylene 2,5-furandicarboxylate-ε-caprolactone: A new bio-based elastomer with high strength and biodegradability

    Directory of Open Access Journals (Sweden)

    M. Y. Zheng

    2017-08-01

    Full Text Available A new bio-based elastomer, poly(butylene 2,5-furandicarboxylate-ε-caprolactone (PBFCL, has been synthesized from 2,5-furandicarboxylic acid, 1,4-butanediol, and ε-caprolactone successfully for the first time. The obtained copolyester was characterized in terms of chemical structure, thermal and mechanical properties, and enzymatic degradability. In PBFCL elastomer, butylene-2,5-furandiacrboxylate units (hard segments crystallize to serve as physical crosslinks while ε-caprolactone polyester diol (soft segments provide flexibility. PBFCL is a multi-blocked copolyester with randomly distributed rigid and soft segments. It possesses original feature of high strength and biodegradability stemming from the uses of aromatic and aliphatic monomers respectively. An important aspect of this new furanic-aliphatic polyester is its tailor-made properties simply achieved by changing the content of hard or soft segments. Typically, PBFCL-40 of optimal composition has Young’s modulus as low as 15.4 MPa, tensile strength as high 24.8 MPa, and elongation as long as 885%.

  10. The effectiveness of the biodegradation of raw and processed polystyrene by mealworms

    Science.gov (United States)

    Leluk, Karol; Hanus-Lorenz, Beata; Rybak, Justyna; Bożek, Magdalena

    2017-11-01

    In our studies biodegradation of four variants of polystyrene was performed. We tested: raw material (PS), processed polystyrene (PSr), building insulation material (EPS) and food packaging boxes (PSp). Materials were characterized by means melt flow ratio (MFR), shore hardness and gloss. The biochemical assessment of macromolecules (proteins, lipids and sugars) in the mealworms organisms fed with tested forms of polystyrene allowed us to set how efficient and beneficial the biodegradation of types of polystyrene is. We also evaluated the variability of bacterial community in larval guts by the use of denaturing gradient gel electrophoresis (DGGE) on the bacterial DNA of 16S rRNA genes amplified in polymerase chain reaction (PCR). The results suggest that EPS and PSp polystyrene are the most digestible for T. molitor larvae. The metabolic degradation of polystyrene is probably strictly connected with the changes in biodiversity of gut bacteria.

  11. The effectiveness of the biodegradation of raw and processed polystyrene by mealworms

    Directory of Open Access Journals (Sweden)

    Leluk Karol

    2017-01-01

    Full Text Available In our studies biodegradation of four variants of polystyrene was performed. We tested: raw material (PS, processed polystyrene (PSr, building insulation material (EPS and food packaging boxes (PSp. Materials were characterized by means melt flow ratio (MFR, shore hardness and gloss. The biochemical assessment of macromolecules (proteins, lipids and sugars in the mealworms organisms fed with tested forms of polystyrene allowed us to set how efficient and beneficial the biodegradation of types of polystyrene is. We also evaluated the variability of bacterial community in larval guts by the use of denaturing gradient gel electrophoresis (DGGE on the bacterial DNA of 16S rRNA genes amplified in polymerase chain reaction (PCR. The results suggest that EPS and PSp polystyrene are the most digestible for T. molitor larvae. The metabolic degradation of polystyrene is probably strictly connected with the changes in biodiversity of gut bacteria.

  12. Application of expanded polystyrene filter for tertiary treatment of domestic waste effluent in the UK

    Directory of Open Access Journals (Sweden)

    Fylypchuk Viktor

    2017-12-01

    Full Text Available The use of expanded polystyrene filters is a promising method for tertiary treatment of domestic waste effluent where biologically treated effluent is filtered through a layer of buoyant polystyrene beads. The advantage of such filters is in the absence of backwashing pumps, containers of clean washing water, while having low energy costs, high resistance of polystyrene to various chemical contaminants that may be in the effluent, easy automation of switching modes.

  13. Fabrication of polystyrene microfluidic devices using a pulsed CO2 laser system

    KAUST Repository

    Li, Huawei

    2013-10-10

    In this article, we described a simple and rapid method for fabrication of droplet microfluidic devices on polystyrene substrate using a CO2 laser system. The effects of the laser power and the cutting speed on the depth, width and aspect ratio of the microchannels fabricated on polystyrene were investigated. The polystyrene microfluidic channels were encapsulated using a hot press bonding technique. The experimental results showed that both discrete droplets and laminar flows could be obtained in the device.

  14. Morphology and Viscoelastic Properties of Polystyrene Blended with Fully Condensed Polyhedral Oligomeric Silsesquioxanes

    National Research Council Canada - National Science Library

    Namani, Madhu; Geng, Hai-Ping; Lee, Andre; Blanski, Rusty L

    2004-01-01

    .... Experiments were performed using a nearly-monodisperse molecular weight polystyrene (PS) blended with varying amounts of two fully condensed POSS molecules surrounded with phenethyl and styrenyl groups...

  15. Renewable Aromatics from the Degradation of Polystyrene under Mild Conditions

    KAUST Repository

    Al Jabri, Nouf M.

    2017-08-01

    Polystyrene (PS) is one of the most important polymers in the plastic sector due to its inexpensive cost as well as many preferred properties. Its international market is expected to achieve $28.2 billion by 2019. Although PS has a high calorific value of 87 GJ tonne-1, there is no a practical method to manage its waste but landfill. As a result, the PS debris in the oceans has reached 70% of the total plastic debris. This issue is considered as the main economical and environmental drivers of converting polystyrene waste into renewable chemical feedstocks. The aim of this work is to develop a catalyst for converting PS into renewable chemicals under mild conditions. We introduce FeCu/Alumina with excellent catalytic activity to fully degrade polystyrene with 66% liquid yield at 250 °C. The GC/MS confirmed that the primary products are in the gasoline range. Next, we present the bimetallic FeCo/Alumina and successfully we have obtained 100% PS conversion and 90% liquid yield with maintaining the products selectivity. Later, the tri-metallic FeCuCo/Alumina was synthesized and showed 100% PS conversion and 91% liquid yield. Surprisingly, ethylbenzene was the major product in which 80 wt. % was achieved with excellent reproducibility. Furthermore, the real waste Styrofoam was thermally and catalytically degraded at 250 °C. Interestingly, a high styrene content of 78 wt. % was recovered after 30 minutes of the reaction under mild conditions. Keeping in mind that a good balance between acidity and basicity is required to convert PS into aromatic under mild reaction conditions catalytically. Finally, the performance of the catalysts was compared to literature reports and showed novel liquid yields. In conclusion, we have synthesized cheap, easy to scale up, and efficient catalysts to fully degrade PS into high liquid yields of aromatics with excellent selectivity.

  16. SIMS studies of interfacial effects in polystyrene thin films

    Science.gov (United States)

    Strzhemechny, Yuri

    Secondary Ion Mass Spectrometry was employed to examine polystyrene chain dynamics near attractive surfaces. Diffusion from a silicon surface and from a sputter- deposited carbon surface was compared in tri-layer sandwiches with a deuterated middle layer. The carbon surface serves as an analog for the carbon-black surface in nanocomposites. Strong segregation of the deuterated component was observed at the native silicon oxide surface, but was inhibited at the carbon surface. A finite element computer program was developed to fit the observed diffusion profiles. The diffusion coefficient D varies with depth superlinearly, scaling roughly as a 3/2-power. Importantly, D in the marker layer region is observed to decrease strongly with time at both the vacuum and solid wall surfaces. The effect of standard wet chemical wafer cleaning procedures on the polystyrene/silicon interface was investigated as well. Deuterated solutions were employed to allow detection of remnant moisture from the cleaning/etching steps, and to indicate the extent of hydrogen termination at the polystyrene/silicon interface. The SIMS data indicated that the surface is effectively terminated by approximately one monolayer of hydrogen after an HF etch step, and by a thin oxide layer after an HCl/peroxide etch. The use of implant standards and a calibrated polymer blend permitted a rough calibration of the deuterium and fluorine concentrations at the interface. Also, deuterium and oxygen were found to be stable under high temperature anneals. The lack of a CD interfacial peak indicated that deuterium is associated with the silicon interface and not with the polymer chains. Oxygen and fluorine contamination peaks were also stable during the anneals. Following exposure to the peroxide/HCl solution, the deuterium level was shown to be much reduced, and the oxygen level is increased, as expected. Despite the wet processes employed in sample preparation, there is no evidence of remnant moisture in the

  17. Proton conducting sulphonated fluorinated poly(styrene) crosslinked electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Soules, A.; Ameduri, B.; Boutevin, B.; David, G. [Institut Charles Gerhardt UMR CNRS 5253 Equipe, Ingenierie et Architectures Macromoleculaires,' ' Ecole Nationale Superieure de Chimie de Montpellier, 8 rue de l' Ecole Normale, 34296 Montpellier, Cedex 05 (France); Perrin, R. [CEA Le Ripault Departement des Materiaux, DMAT/SCMF/LSTP, BP16 - 37260 Monts (France); Gebel, G. [Structure et Proprietes des Architectures Moleculaires UMR 5819 (CEA-CNRS-UJF), INAC, SPrAM, CEA Grenoble, 17 Rue des Martyrs, 38054 Grenoble, Cedex 9 (France)

    2011-10-15

    Potential membranes for polymer electrolyte membrane fuel cell based on crosslinked sulphonated fluorinated polystyrenes (PS) were synthesised in two steps. First, azide-telechelic polystyrene was obtained by iodine transfer polymerisation of styrene in the presence of 1,6-diiodoperfluorohexane followed by azido chain-end functionalisation. Then azide-telechelic polystyrene was efficiently crosslinked with 1,10-diazido-1H,1H,2H,2H,9H,9H,10H,10H-perfluorodecane under UV irradiation. After 45 min only, almost completion of azide crosslinking could be achieved, resulting in crosslinked membranes with insoluble fractions higher than 95%. The sulphonation of the crosslinked membranes afforded ionic exchange capacities (IECs) ranging from 2.2 to 3.2 meq g{sup -1}. The hydration number was shown to be very high (from 30 to 75), depending on both the content of perfluorodecane and of sulphonic acid groups. The morphology of the membranes, assessed by small-angle X-ray scattering, was found to be a lamellar-type structure with two types of ionic domains. For the membrane that exhibited an IEC value of 2.2 meq.g{sup -1}, proton conductivity was in the same range as that of Nafion {sup registered} (120-135 mS.cm{sup -1}), whereas the membrane IEC value of 3.2 meq.g{sup -1} showed a proton conductivity higher than that of Nafion {sup registered} in liquid water from 25 to 80 C, though a high water uptake. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Simulation and fabrication of integrated polystyrene microlens in microfluidic system

    KAUST Repository

    Fan, Yiqiang

    2013-05-17

    This paper presents a simple and quick method to integrate microlens with the microfluidics systems. The polystyrene (PS) based microlens is fabricated with the free surface thermal compression molding methods, a thin PS sheet with the microlens is bonded to a PMMA substrate which contains the laser ablated microchannels. The convex profiler of the microlens will give a magnified images of the microchannels for easier observation. Optical simulation software is being used for the design and simulation of the microlens to have optimal optical performance with the desired focal length. A microfluidic system with the integrated PS microlens is also fabricated for demonstration.

  19. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

    2003-01-01

    above the linear viscoelastic prediction at intermediate strains, indicating strain hardening. The steady elongational viscosities are monotone decreasing functions of elongation rate. At elongation rates larger than the inverse reptation time, the steady elongational viscosity scales linearly......Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...... with molar mass at fixed elongation rate....

  20. Vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria calculations for polystyrene plus methyleyclohexane and polystyrene plus cyclohexane solutions

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2006-01-01

    This paper presents the vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria predictions for polystyrene in two theta solvents: cyclohexane and methylcyclohexane. VLE calculations were performed with the Elbro free volume method and a modified version of the PC-SAFT method, as well...... as with three UNIFAC type group contribution models: Entropic Free Volume + UNIFAC VLE 1 coeff., Entropic Free Volume + UNIFAC VLE 2coeff., and Oishi-Prausnitz + UNIFAC VLE 2coeff. Solvent activities were calculated for the polystyrene + cyclohexane and polystyrene + methylcyclohcxane solutions, and compared...

  1. Holographic investigations of azobenzene-containing low-molecular-weight compounds in pure materials and binary blends with polystyrene.

    Science.gov (United States)

    Audorff, Hubert; Walker, Roland; Kador, Lothar; Schmidt, Hans-Werner

    2011-11-04

    This paper reports on the synthesis and the thermal and optical properties of photochromic low-molecular-weight compounds, especially with respect to the formation of holographic volume gratings in the pure materials and in binary blends with polystyrene. Its aim is to provide a basic understanding of the holographic response with regard to the molecular structure, and thus to show a way to obtain suitable rewritable materials with high sensitivity for holographic data storage. The photoactive low-molecular-weight compounds consist of a central core with three or four azobenzene-based arms attached through esterification. Four different cores were investigated that influence the glass transition temperature and the glass-forming properties. Additional structural variations were introduced by the polar terminal substituent at the azobenzene chromophore to fine-tune the optical properties and the holographic response. Films of the neat compounds were investigated in holographic experiments, especially with regard to the material sensitivity. In binary blends of the low-molecular-weight compounds with polystyrene, the influence of a polymer matrix on the behavior in holographic experiments was studied. The most promising material combination was also investigated at elevated temperatures, at which the holographic recording sensitivity is even higher. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Elongational viscosity of monodisperse and bidisperse polystyrene melts

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    The startup and steady uniaxial elongational viscosity have been measured for two monodisperse polystyrene melts with molecular weights of 52 kg/mole (PS52K) and 103 kg/mole (PS103K), and for three bidisperse polystyrene melts. The bidisperse melts consist of PS103K or PS52K and a monodisperse...... (closed loop proportional regulator) using the laser in such a way that the stretch rate at the neck is kept constant. The rheometer has been described in more detail in (A. Bach, H.K. Rasmussen and O. Hassager, Journal of Rheology, 47 (2003) 429). PS390K show a decrease in the steady viscosity as a power......-law function of the elongational rate (A. Bach, K. Almdal, H.K. Rasmussen and O. Hassager, Macromolecules 36 (2003) 5174). PS52K and PS103K show that the steady viscosity has a maximum that is respectively 100% and 50% above 3 times the zero-shear-rate viscosity. The bidisperse melts show a significant...

  3. Conversion of waste polystyrene through catalytic degradation into valuable products

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Jasmin; Jan, Muhammad Rasul; Adnan [University of Peshawar, Peshawar (Pakistan)

    2014-08-15

    Waste expanded polystyrene (EPS) represents a source of valuable chemical products like styrene and other aromatics. The catalytic degradation was carried out in a batch reactor with a mixture of polystyrene (PS) and catalyst at 450 .deg. C for 30 min in case of Mg and at 400 .deg. C for 2 h both for MgO and MgCO{sub 3} catalysts. At optimum degradation conditions, EPS was degraded into 82.20±3.80 wt%, 91.60±0.20 wt% and 81.80±0.53 wt% liquid with Mg, MgO and MgCO{sub 3} catalysts, respectively. The liquid products obtained were separated into different fractions by fractional distillation. The liquid fractions obtained with three catalysts were compared, and characterized using GC-MS. Maximum conversion of EPS into styrene monomer (66.6 wt%) was achieved with Mg catalyst, and an increase in selectivity of compounds was also observed. The major fraction at 145 .deg. C showed the properties of styrene monomer. The results showed that among the catalysts used, Mg was found to be the most effective catalyst for selective conversion into styrene monomer as value added product.

  4. Accurately controlled sequential self-folding structures by polystyrene film

    Science.gov (United States)

    Deng, Dongping; Yang, Yang; Chen, Yong; Lan, Xing; Tice, Jesse

    2017-08-01

    Four-dimensional (4D) printing overcomes the traditional fabrication limitations by designing heterogeneous materials to enable the printed structures evolve over time (the fourth dimension) under external stimuli. Here, we present a simple 4D printing of self-folding structures that can be sequentially and accurately folded. When heated above their glass transition temperature pre-strained polystyrene films shrink along the XY plane. In our process silver ink traces printed on the film are used to provide heat stimuli by conducting current to trigger the self-folding behavior. The parameters affecting the folding process are studied and discussed. Sequential folding and accurately controlled folding angles are achieved by using printed ink traces and angle lock design. Theoretical analyses are done to guide the design of the folding processes. Programmable structures such as a lock and a three-dimensional antenna are achieved to test the feasibility and potential applications of this method. These self-folding structures change their shapes after fabrication under controlled stimuli (electric current) and have potential applications in the fields of electronics, consumer devices, and robotics. Our design and fabrication method provides an easy way by using silver ink printed on polystyrene films to 4D print self-folding structures for electrically induced sequential folding with angular control.

  5. Slip and flow dynamics of polydisperse thin polystyrene films.

    Science.gov (United States)

    Sabzevari, Seyed Mostafa; McGraw, Joshua D.; Jacobs, Karin; Wood-Adams, Paula M.

    2015-03-01

    We investigate the slip of binary and ternary mixtures of nearly monodisperse polystyrene samples on Teflon-coated (AF2400) silicon wafers using dewetting experiments. Binary mixtures of long and short chains along with ternary mixtures with a fixed weight-average molecular weight Mw but different number-average molecular weight Mn were prepared. Thin films of ca. 200 nm were spin coated on mica from polymer solutions and transferred to Teflon substrates. Above the glass transition temperature Tg the films break up via nucleation and growth of holes. The hole growth rate and rim morphology are monitored as a function of Mn and annealing protocol of the films before transfer to Teflon substrates. Slip properties, accessed using hydrodynamic models, and flow dynamics are then examined and compared. We found that the rim morphology and slip of polystyrene blends on Teflon depends on the molecular weight distribution. Similarly, flow dynamics is affected by the presence of short chains in mixture. Moreover, we can provoke differences in slip by choosing appropriate annealing and film transfer protocols for PS films that have first been spin cast on mica surfaces.

  6. 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate / hydroxyl apatite nano particle scaffolds: Potential materials for bone regeneration applications

    Science.gov (United States)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas; Bhatia, Gaurav; Nim, Lovedeep; Kaur, Manpreet; Arora, Daljit Singh

    2017-05-01

    Bioresorbable and bioactive scaffolds are promising materials for various biomedical applications including bone regeneration and drug delievrery. Authors present bioactive scaffolds prepared from 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate) (PBSu-DCH) with different amount of hydroxyl apatite nanoparticles (nHAp) by solvent casting and particulate leaching techniques. Different weight ratios of nHAp (i.e. 0, 5 and 10 wt %) with fixed weight ratio (i.e. 10 wt %) of PBSu-DCH polymer have been prepared. Scaffolds have been assessed for their morphology, bioactivity, degradation, drug release and biological properties including cytotoxicity, cell attachment using MG-63 cell line and antimicrobial activity. Effectual drug release has been measured by incorporating gentamycin as an antibiotic in the scaffolds. The study is aimed at developing new biodegradable scaffolds to be used in skull, jaw and tooth socket for preserving bone mass.

  7. Meso-Structuring of SiCN Ceramics by Polystyrene Templates

    Directory of Open Access Journals (Sweden)

    Julia-Katharina Ewert

    2015-03-01

    Full Text Available A simple one-pot synthesis of well-defined PS-silazane nano-composites (polystyrene, PS is described. In contrast to the, thus far, used two-step procedure ((1 assembly of a PS template bed and (2 careful filling of the voids between the PS spheres, which is restricted to macro structuring, we are able to simply mix the PS template and a commercially available silazane precursor HTT-1800 in toluene. The key is the alteration of the zeta potential of the PS template leading to a homogeneous dispersion in the silazane-toluene mixture. Removal of solvent gives rise to a highly ordered PS-silazane nano-composites and subsequent pyrolysis leads to mesoporous silicon carbonitride (SiCN materials. The one-pot procedure has two advantages: easy upscaling and the use of PS spheres smaller than 100 nm in diameter, here 60 nm. The PS template was characterized by photon correlation spectroscopy, zeta potential measurements, scanning electron microscopy (SEM, and thermal gravimetric analysis (TGA. The resulting mesoporous SiCN materials were analyzed by SEM, transmission electron microscopy (TEM, nitrogen sorption analysis, and Fourier transform infrared measurements (FT-IR.

  8. New nanocomposites of polystyrene with polyaniline doped with lauryl sulfuric acid

    Science.gov (United States)

    Pud, A. A.; Nikolayeva, O. A.; Vretik, L. O.; Noskov, Yu. V.; Ogurtsov, N. A.; Kruglyak, O. S.; Fedorenko, E. A.

    2017-08-01

    This work is concentrated on synthesis and investigation of new core-shell nanocomposites of polystyrene (PS) with doped polyaniline (PANI). The latex containing PS nanoparticles with sizes of 15-30 nm was prepared by microemulsion polymerization of styrene in water media. The PS/PANI nanocomposites were synthesized by chemical oxidative polymerization of aniline in the PS latex media in a presence of lauryl sulfuric acid (LSA), which served as both dopant and plasticizer. The real content of PANI in the synthesized nanocomposites was determined by UV-Vis spectroscopy method. The composition of the nanocomposites and oxidation state of the doped polyaniline were characterized by FTIR spectroscopy. The core-shell morphology of the nanocomposite nanoparticles was proved by transmission and scanning electron microscopy. It was found that conductivity and thermal behavior in air of these nanocomposites not only nonlinearly depended on the doped polyaniline content but also were strongly effected both by plasticizing properties of the acid-dopant and presence of the polyaniline shell. A possibility of application of these nanocomposites as sensor materials has been demonstrated.

  9. Field efficacy of expanded polystyrene and shredded waste polystyrene beads for mosquito control in artificial pools and field trials, Islamic Republic of Iran.

    Science.gov (United States)

    Soltani, A; Vatandoost, H; Jabbari, H; Mesdaghinia, A R; Mahvi, A H; Younesian, M; Hanafi-Bojd, A A; Bozorgzadeh, S

    2012-10-01

    Concerns about traditional chemical pesticides has led to increasing research into novel mosquito control methods. This study compared the effectiveness of 2 different types of polystyrene beads for control of mosquito larvae in south-east Islamic Republic of Iran. Simulated field trials were done in artificial pools and field trials were carried out in 2 villages in an indigenous malaria area using WHO-recommended methods. Application of expanded polystyrene beads or shredded, waste polystyrene chips to pool surfaces produced a significant difference between pre-treatment and post-treatment density of mosquitoes (86% and 78% reduction respectively 2 weeks after treatment). There was no significant difference between the efficacy of the 2 types of material. The use of polystyrene beads as a component of integrated vector management with other supportive measures could assist in the control of mosquito-borne diseases in the Islamic Republic of Iran and neighbouring countries.

  10. The properties of the wood-polystyrene interphase determined by inverse gas chromatography

    Science.gov (United States)

    John Simonsen; Zhenqiu Hong; Timothy G. Rials

    1997-01-01

    The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inoranic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass...

  11. Colonic necrosis due to calcium polystyrene sulfonate (Kalimate not suspended in sorbitol

    Directory of Open Access Journals (Sweden)

    María Dolores Castillo-Cejas

    2013-04-01

    Full Text Available Cation-exchange resins are used in the management of hyperkalemia, particularly in patients with end-stage renal disease. These resins were associated with gastrointestinal tract lesions, especially sodium polystyrene sulfonate (Kayexalate mixed with sorbitol. We present a case of colonic necrosis after the administration of calcium polystyrene sulfonate (Kalimate not suspended in sorbitol.

  12. Enhanced polystyrene surface mobility under carbon dioxide at low temperature for nanoparticle embedding control

    NARCIS (Netherlands)

    Yang, Qiuyan; Xu, Qun; Loos, Katja

    2015-01-01

    The surface properties of polystyrene (PS) films under carbon dioxide (CO2) were studied via a particle embedding technique at quite a low temperature range (308 to 323 K) in which polystyrene is typically considered to be in a glassy state without CO2. Atomic force microscope (AFM) technique with a

  13. Polystyrene Microbeads by Dispersion Polymerization: Effect of Solvent on Particle Morphology

    Directory of Open Access Journals (Sweden)

    Lei Jinhua

    2014-01-01

    Full Text Available Polystyrene microspheres (PS were synthesized by dispersion polymerization in ethanol/2-Methoxyethanol (EtOH/EGME blend solvent using styrene (St as monomer, azobisisobutyronitrile (AIBN as initiator, and PVP (polyvinylpyrrolidone K-30 as stabilizer. The typical recipe of dispersion polymerization is as follows: St/Solvent/AIBN/PVP = 10 g/88 g/0.1 g/2 g. The morphology of polystyrene microspheres was characterized by the scanning electron microscopy (SEM and the molecular weights of PS particles were measured by the Ubbelohde viscometer method. The effect of ethanol content in the blend solvent on the morphology and molecular weight of polystyrene was studied. We found that the size of polystyrene microspheres increased and the molecular weight of polystyrene microspheres decreased with the decreasing of the ethanol content in the blend solvent from 100 wt% to 0 wt%. What is more, the size monodispersity of polystyrene microspheres was quite good when the pure ethanol or pure 2-Methoxyethanol was used; however when the blend ethanol/2-Methoxyethanol solvent was used, the polystyrene microspheres became polydisperse. We further found that the monodispersity of polystyrene microspheres can be significantly improved by adding a small amount of water into the blend solvent; the particles became monodisperse when the content of water in the blend solvent was up to 2 wt%.

  14. A fresh study of optical and thermal properties of polystyrene solutions

    Indian Academy of Sciences (India)

    Polymers have immense practical applications and one such polymer is polystyrene. It is a linear polymer and useful for plastic optical components. The optical and thermal properties of polystyrene solutions are investigated in this paper making use of the ultrasonic velocity and fluid parameters. The results reveal a number ...

  15. Modification of Jute Fibers with Polystyrene via Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Plackett, David; Jankova, Katja Atanassova; Egsgaard, Helge

    2005-01-01

    Atom transfer radical polymerization (ATRP) was investigated as a method of covalently bonding polystyrene to jute (Corchorus capsularis) and as a possible approach to fiber composites with enhanced properties. Jute fibers were modified with a brominated initiator and subsequently ATRP modified...... to attach polystyrene and then examined using SEM, DSC, TGA, FTIR, XPS, elemental analysis, and Py-GC-MS. These techniques confirmed that polystyrene had been covalently bound to the fibers and consequently ATRP-modified jute fiber mats were used to prepare hot-pressed polystyrene composites. Composite...... applications, we conclude that further optimization of the ATRP method is required, possibly targeting higher and more uniform loading of polystyrene on the fibers....

  16. 'Dialyzable' Carbosilane Dendrimers as Soluble Supports in Organic Synthesis: Proof of principle, application and diafiltration performance

    NARCIS (Netherlands)

    Wander, M.

    2012-01-01

    Since the development of polystyrene as (insoluble) support for the synthesis of peptides by Merrifield in the 1960s, the application of supported synthesis in both industrial and academic research has increased. The introduction of dendrimers as supports solved many of the problems arising from the

  17. Durability of Modified Expanded Polystyrene Concrete after Dynamic Cyclic Loading

    Directory of Open Access Journals (Sweden)

    Wenbo Shi

    2016-01-01

    Full Text Available EPS concrete was produced by mixing the expanded polystyrene spheres (EPS and polymer emulsion and thickener to the matrix concrete, and this concrete had good vibration energy absorption characteristics. Based on the experimental data obtained on EPS volume ratio of 0%, 20%, 30%, and 40% by replacing matrix or coarse aggregate, the two design styles had nearly the same compressive strength. By applying frequency of 5 Hz, 50000 or 100000 times, 40 KN, 50 KN, and 60 KN cyclic loading, it is shown that the higher the inclusion size was, the lower the compressive strength of the EPS concrete would be; the larger the applying dynamic cyclic load was, the more obvious the compressive strength changing would be. Meanwhile, the strength of EPS concrete had no evident change after durability test. The results of this research had practical significance on using EPS concrete in some long-term cyclic dynamic load engineering.

  18. Expanded polystyrene (EPS) floats for surveillance of Ochlerotatus japonicus.

    Science.gov (United States)

    Scott, Jamesina J; Crans, Wayne J

    2003-12-01

    Blocks of expanded polystyrene (EPS) were placed in a variety of habitats to investigate their potential as an egg-collection device for container-dwelling Aedes and Ochlerotatus species. Eggs from Ochlerotatus japonicus, Oc. triseriatus, Oc. hendersoni, and Aedes albopictus were collected with EPS floats. The float provides an inexpensive, low-maintenance alternative to the Centers for Disease Control ovitrap for sampling container-dwelling mosquito species that are important vectors of disease. Eggs collected on the floats have many potential applications, including use in routine population surveillance; detection of Oc. japonicus, Ae. albopictus, and other container-dwelling species in new areas; species distribution studies; natural transovarial transmission studies; ovipositional studies; collection of local field populations for insecticide resistance assays; assessment of adulticiding efficacy; and establishment of new laboratory colonies.

  19. PMMA to Polystyrene bonding for polymer based microfluidic systems

    KAUST Repository

    Fan, Yiqiang

    2013-03-29

    A thermal bonding technique for Poly (methylmethacrylate) (PMMA) to Polystyrene (PS) is presented in this paper. The PMMA to PS bonding was achieved using a thermocompression method, and the bonding strength was carefully characterized. The bonding temperature ranged from 110 to 125 C with a varying compression force, from 700 to 1,000 N (0.36-0.51 MPa). After the bonding process, two kinds of adhesion quantification methods were used to measure the bonding strength: the double cantilever beam method and the tensile stress method. The results show that the bonding strength increases with a rising bonding temperature and bonding force. The results also indicate that the bonding strength is independent of bonding time. A deep-UV surface treatment method was also provided in this paper to lower the bonding temperature and compression force. Finally, a PMMA to PS bonded microfluidic device was fabricated successfully. © 2013 Springer-Verlag Berlin Heidelberg.

  20. Preparation of Dithizone Functionalized Polystyrene for Detecting Heavy Metal Ion

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hyeon Ho; Kim, Younghun [Kwangwoon University, Seoul (Korea, Republic of)

    2015-04-15

    Colorimetric sensors were usually used to detect specific metal ions using selective color change of solutions. While almost organic dye in colorimetric sensors detected single molecule, dithizone (DTZ) solution could be separately detected above 5 kinds of heavy metal ions by the change of clear color. Namely, DTZ could be used as multicolorimetric sensors. However, DTZ was generally used as aqueous type and paper/pellet-type DTZ was not reported yet. Therefore, in this work, polystyrene (PS) was prepared to composite with DTZ and then DTZ/PS pellet was obtained, which was used to selectively detect 10 kinds of heavy metal ions. When 10 ppm of Hg and Co ions was exposed in DTZ/PS pellets, clear color change was revealed. It is noted that DTZ/PS pellet could be used in detecting of heavy metal ion as dry type.

  1. B-Loaded Plastic Scintillator on the Base of Polystyrene

    CERN Document Server

    Brudanin, V B; Nemchenok, I B; Smolnikov, A A

    2000-01-01

    A method to produce polystyrene-based plastic scintillators with boron concentration from 0.38 to 5.0% of boron have been developed. o-Carborane was used as B-containing additive. The results of investigations of the optical, spectral and scintillation characteristics are presented and discussed. It is shown that 5% B-loaded scintillator has a light output as much as 70% relative to the unloaded one. High efficiency for thermal neutron registration achieved for produced samples makes it possible to use such scintillators in complex neutron high sensitive spectrometers. Measured level of radioactive contamination in this scintillation materials is good enough for using the B-loaded scintillators in the proposed large scale neutrino experiments.

  2. Renewable Aromatics from the Degradation of Polystyrene under Mild Conditions

    KAUST Repository

    Jabri, Nouf M

    2017-05-25

    A bimetallic FeCu/alumina catalyst was prepared and characterized. It showed excellent catalytic activity to quantitatively convert polystyrene (PS) into aromatics at low temperatures. A clear goldish yellow liquid was produced at 250 °C in a batch reactor without distillation. A liquid yield of 66% in an inert environment was achieved without the formation of coke and gas by-products. An exposure time of 90 min. and a catalyst loading of 200 mg were considered as an optimum condition to minimize the styrene re-polymerization. The gas chromatography/ mass spectrometry (GC/MS) analysis confirms that the primary products are styrene, ethylbenzene, cumene, toluene and α-methylstyrene.

  3. Polyvinyl alcohol coating of polystyrene inertial confinement fusion targets

    Science.gov (United States)

    Annamalai, P.; Lee, M. C.; Crawley, R. L.; Downs, R. L.

    1985-01-01

    An inertial confinement fusion (ICF) target made of polystyrene is first levitated in an acoustic field. The surface of the target is then etched using an appropriate solution (e.g., cyclohexane) to enhance the wetting characteristics. A specially prepared polyvinyl alcohol solution is atomized using an acoustic atomizer and deposited on the surface of the target. The solution is air dried to form a thin coating (2 microns) on the target (outside diameter of about 350-850 microns). Thicker coatings are obtained by repeated applications of the coating solutions. Preliminary results indicate that uniform coatings may be achievable on the targets with a background surface smoothness in the order of 1000 A.

  4. The influence of photodegradation on environmental stress cracking of polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Alexandre R.; Araujo, Elmo S. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: rangelrs@yahoo.com.br; Medeiros, Eliton S. [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia de Materiais]. E-mail: eliton@cnpdia.embrapa.br; Amorim, Karina L.E.; Rabello, Marcelo S.; Melo, Tomas J.A. [Universidade Federal de Campina Grande, PB (Brazil). Dept. de Engenharia de Materiais]. E-mail: marcelo@dema.ufcg.edu.br

    2005-07-01

    In this work we aimed to investigate the influence of the photodegradation level on the environmental stress cracking (ESC) of polystyrene (PS). Tensile specimens were obtained by injection moulding, exposed to artificial ultraviolet (UV) radiation for different time intervals then submitted to ESC evaluation. It was observed that the previous photodegradation of PS accelerated the ESC. The micrographs showed that the internal mechanisms of deformation were changed. Further results indicated that the UV radiation modified the PS molar mass and because of the presence of oxygen during the exposure of the polymer to UV radiation, carbonyl groups were incorporated to the polymer structure. These modifications caused rising liquid absorption with the photodegradation level which may explain the ESC acceleration. (author)

  5. Preparation and characterization of chitosan - polystyrene polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, N. P., E-mail: naveenmascarenhas@gmail.com; Crasta, V. [Department of Physics, St Joseph Engineering College, Vamanjoor-575028 (India); Gonsalves, R. A.; Goveas, J. J. [Department of Chemistry, St Aloysius College (Autonomous), Mangalore 575003 (India); Shetty, T. C. S. [Department of Post Graduate Studies in Physics, St Aloysius College, (Autonomous), Mangalore 575003 (India)

    2016-05-23

    To enhance the physical and mechanical properties of Chitosan (CS) and to improve the functionality of CS towards some specific applications, we have blended CS with polystyrene (PS) to form blended films. The Fourier Transform Infrared Spectroscopy (FT-IR) has been performed on the prepared films to confirm functional groups and formation of the blends. Thermal analysis (TGA and DSC) is carried out to study thermal stability of the blended films. From X-ray diffraction (XRD) studies, the material reveals amorphous nature and hence it may be used for adsorption process. The versatility of the blends, such as film-forming ability, hydrophilicity, biodegradability and biocompatibility are comparable with the existing blends.

  6. The contribution of polystyrene nanospheres towards the crystallization of proteins.

    Directory of Open Access Journals (Sweden)

    Johanna M Kallio

    Full Text Available BACKGROUND: Protein crystallization is a slow process of trial and error and limits the amount of solved protein structures. Search of a universal heterogeneous nucleant is an effort to facilitate crystallizability of proteins. METHODOLOGY: The effect of polystyrene nanospheres on protein crystallization were tested with three commercial proteins: lysozyme, xylanase, xylose isomerase, and with five research target proteins: hydrophobins HFBI and HFBII, laccase, sarcosine dimethylglycine N-methyltransferase (SDMT, and anti-testosterone Fab fragment 5F2. The use of nanospheres both in screening and as an additive for known crystallization conditions was studied. In screening, the addition of an aqueous solution of nanosphere to the crystallization drop had a significant positive effect on crystallization success in comparison to the control screen. As an additive in hydrophobin crystallization, the nanospheres altered the crystal packing, most likely due to the amphiphilic nature of hydrophobins. In the case of laccase, nanospheres could be used as an alternative for streak-seeding, which insofar had remained the only technique to produce high-diffracting crystals. With methyltransferase SDMT the nanospheres, used also as an additive, produced fewer, larger crystals in less time. Nanospheres, combined with the streak-seeding method, produced single 5F2 Fab crystals in shorter equilibration times. CONCLUSIONS: All in all, the use of nanospheres in protein crystallization proved to be beneficial, both when screening new crystallization conditions to promote nucleation and when used as an additive to produce better quality crystals, faster. The polystyrene nanospheres are easy to use, commercially available and close to being inert, as even with amphiphilic proteins only the crystal packing is altered and the nanospheres do not interfere with the structure and function of the protein.

  7. Optical properties of highly compressed polystyrene: An ab initio study

    Science.gov (United States)

    Hu, S. X.; Collins, L. A.; Colgan, J. P.; Goncharov, V. N.; Kilcrease, D. P.

    2017-10-01

    Using all-electron density functional theory, we have performed an ab initio study on x-ray absorption spectra of highly compressed polystyrene (CH). We found that the K -edge shifts in strongly coupled, degenerate polystyrene cannot be explained by existing continuum-lowering models adopted in traditional plasma physics. To gain insights into the K -edge shift in warm, dense CH, we have developed a model designated as "single mixture in a box" (SMIAB), which incorporates both the lowering of the continuum and the rising of the Fermi surface resulting from high compression. This simple SMIAB model correctly predicts the K -edge shift of carbon in highly compressed CH in good agreement with results from quantum molecular dynamics (QMD) calculations. Traditional opacity models failed to give the proper K -edge shifts as the CH density increased. Based on QMD calculations, we have established a first-principles opacity table (FPOT) for CH in a wide range of densities and temperatures [ρ =0.1 -100 g /c m3 and T =2000 -1 000 000 K ]. The FPOT gives much higher Rosseland mean opacity compared to the cold-opacity-patched astrophysics opacity table for warm, dense CH and favorably compares to the newly improved Los Alamos atomic model for moderately compressed CH (ρCH≤10 g /c m3 ), but remains a factor of 2 to 3 higher at extremely high densities (ρCH≥50 g /c m3 ). We anticipate the established FPOT of CH will find important applications to reliable designs of high-energy-density experiments. Moreover, the understanding of K -edge shifting revealed in this study could provide guides for improving the traditional opacity models to properly handle the strongly coupled and degenerate conditions.

  8. X-ray excited luminescence of polystyrene composites loaded with SrF{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Demkiv, T.M.; Halyatkin, O.O.; Vistovskyy, V.V. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Hevyk, V.B. [Ivano-Frankivsk National Technical University of Oil and Gas, 15 Karpatska St., 76019 Ivano-Frankivsk (Ukraine); Yakibchuk, P.M. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Gektin, A.V. [Institute for Scintillation Materials, NAS of Ukraine, 60 Lenina Ave, 61001 Kharkiv (Ukraine); Voloshinovskii, A.S. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine)

    2017-03-01

    The polystyrene film nanocomposites of 0.3 mm thickness with embedded SrF{sub 2} nanoparticles up to 40 wt% have been synthesized. The luminescent and kinetic properties of the polystyrene composites with embedded SrF{sub 2} nanoparticles upon the pulse X-ray excitation have been investigated. The luminescence intensity of the pure polystyrene scintillator film significantly increases when it is loaded with the inorganic SrF{sub 2} nanoparticles. The film nanocomposites show fast (∼2.8 ns) and slow (∼700 ns) luminescence decay components typical for a luminescence of polystyrene activators (p-Terphenyl and POPOP) and SrF{sub 2} nanoparticles, respectively. It is revealed that the fast decay luminescence component of the polystyrene composites is caused by the excitation of polystyrene by the photoelectrons escaped from the nanoparticles due to photoeffect, and the slow component is caused by reabsorption of the self-trapped exciton luminescence of SrF{sub 2} nanoparticles by polystyrene.

  9. Adhesion of smooth and rough phenotypes of Flavobacterium psychrophilum to polystyrene surfaces.

    Science.gov (United States)

    Högfors-Rönnholm, E; Norrgård, J; Wiklund, T

    2015-05-01

    Phenotypic smooth cells of the fish pathogenic bacterium Flavobacterium psychrophilum have previously been reported to be more adhesive to polystyrene surfaces than corresponding rough cells. In this study, the adhesion ability of smooth and rough cells of F. psychrophilum to polystyrene surfaces was investigated in detail with a crystal violet staining method. By treating both polystyrene surfaces with fish mucus and carbohydrates and the bacterial cells with carbohydrates, the involvement of lectins in the adhesion process was investigated. Smooth cells showed significantly higher adhesion ability to untreated polystyrene surfaces compared with corresponding rough cells and increasing water hardness had an inhibitory effect on the adhesion. Treatment of polystyrene surfaces with D-glucose, D-galactose and fish mucus increased the adhesion ability of smooth cells to polystyrene. Furthermore, treatment of the smooth cells with D-glucose, D-galactose and sialic acid decreased the adhesion ability of the cells, indicating that the adhesion is likely mediated by complementary lectins on the surface of the cells. Sodium (meta)periodate treatment of smooth cells also decreased the adhesion ability to polystyrene, suggesting that the lectins, such as the dominating sialic acid-binding lectin, are probably localized in the extracellular polysaccharides surrounding the cells. © 2014 John Wiley & Sons Ltd.

  10. Agarwal N Synthesis, photophysical and electrochemical proper-ties ...

    Indian Academy of Sciences (India)

    Administrator

    A solid-polymer-electrolyte direct methanol fuel cell. (DMFC) with Pt–Ru nanoparticles supported onto poly(3,4-ethylenedioxythiophene) and polystyrene sulphonic acid polymer composite as anode. 381. Silva M M S see Dutra R F. 911. Singh A see Venugopalan P. 739. Singh A P see Gupta R. 311. Singh D. Synthesis and ...

  11. Fabrication of microlens and microlens array on polystyrene using CO 2 laser

    KAUST Repository

    Fan, Yiqiang

    2011-11-01

    This study presents a new process for fabricating microlens and microlens arrays directly on a surface of polystyrene using a CO2 laser. The working spot of the polystyrene is heated locally by a focused CO2 laser beam, which tends to have a hyperboloid profile due to the surface tension and can be used as a microlens. The microlenses with different dimensions were fabricated by changing the power of the laser beam. Microlens array was also fabricated with multiple scans of the laser beam on the polystyrene surface. © (2012) Trans Tech Publications, Switzerland.

  12. Solid-Phase Immunoassay of Polystyrene-Encapsulated Semiconductor Coreshells for Cardiac Marker Detection

    Directory of Open Access Journals (Sweden)

    Sanghee Kim

    2012-01-01

    Full Text Available A solid-phase immunoassay of polystyrene-encapsulated semiconductor nanoparticles was demonstrated for cardiac troponin I (cTnI detection. CdSe/ZnS coreshells were encapsulated with a carboxyl-functionalized polystyrene nanoparticle to capture the target antibody through a covalent bonding and to eliminate the photoblinking and toxicity of semiconductor luminescent immunosensor. The polystyrene-encapsulated CdSe/ZnS fluorophores on surface-modified glass chip identified cTnI antigens at the level of ~ng/mL. It was an initial demonstration of diagnostic chip for monitoring a cardiovascular disease.

  13. Glass transition-related thermorheological complexity in polystyrene melts

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y-H [Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan (China)

    2007-11-21

    The relaxation-modulus G(t) functional forms covering the whole time range are given by incorporating a stretched exponential for the structural- (glassy-) relaxation process into the extended reptation theory (ERT; for entangled systems) or the Rouse theory (for entanglement-free systems). The creep compliance J(t) curves of two entangled (A and B) and one entanglement-free (C) polystyrene samples (Plazek) as well as the viscoelastic spectra G*({omega}) of four entanglement-free polystyrene samples (Inoue et al) have been quantitatively analyzed in terms of the given G(t) functional forms. In such quantitatively successful analyses, the ERT or the Rouse theory works as the frame of reference in both the line shape and timescale. The thermorheological complexity in the J(t) curves is explained naturally and precisely by the temperature dependence of the energetic-interaction-derived structural relaxation being stronger than that of the entropic ERT or Rouse dynamics in a simple way. Structural-relaxation times {tau}{sub S} (= 18s{sup '}K{sup '}) of all the studied samples are equally well separated into two decoupled quantities: the structural-growth parameter s{sup '} and the frictional factor K{sup '} (for the Rouse-Mooney or Rouse modes of motion). The separation is fundamentally a clean-cut process: s{sup '} is determined entirely by the line shape of J(t) or G*({omega}) while K{sup '} is calculated from the timescale shifting factor obtained from the superposition of the calculated curves onto the measured. The glassy-relaxation strength A{sub G}{sup f} and the stretching parameter {beta} extracted from the J(t) and G*({omega}) results over the glassy-relaxation region are in good agreement. The glass-transition temperature T{sub g} is defined as corresponding to {tau}{sub S} 1000 s for all the studied samples. The {tau}{sub S}, s{sup '} and K{sup '} data points of samples A, B and C extracted from their J(t) curves

  14. Destructive effect of polystyrene sulfonate on the structure of hemoproteins

    Science.gov (United States)

    Saburova, E. A.; Basova, L. V.; Dybovskaya, Yu. N.; Sukhorukov, B. I.

    2006-08-01

    The mechanism of the destruction of horse heart hemoglobin (Hb) and spermwhale muscle myoglobin (Mb), two hem-containing proteins, by polystyrene sulfonate, an anionic polyelectrolyte, was studied. Measurements of the optical absorption of the prostetic group of the hem in the visible spectrum and of the circular dichroism in the absorption bands of the peptide groups and aromatic amino acid residues demonstrated that the compact structure of both proteins experiences destruction in the presence of polystyrene sulfonate (PSS) at PSS concentrations ten times as low as that of the protein (in wt %) and that the content of α-helix structure in Hb and Mb decreases from 81% in the native state to 43% in their complexes with PSS. The distinctions in the mechanisms of the destruction of Hb and Mb by PSS were found to be as follows: (1) in contrast to Mb, Hb forms insoluble complexes with PSS at low PSS concentrations and (2) Mb-PSS solutions at Mb-to-PSS ratios >1 were found to contain free hems (that absorb at 397 nm), a feature not observed for Hb; the kinetics of the destruction of both the proteins by the polyelectrolyte was demonstrated to be a two-stage process. The first stage of the destruction of Hb (τ ≈ 24.5 s) was found to be four times as slow as that of Mb (τ ≈ 6 s); the second (slow) stage had a halftime of ˜6 h for both the proteins under study. To determine the localization of regions at the protein molecule surface that are capable of binding polyelectrolyte molecules, the distribution of the electrostatic potential over the surface of the Hb and Mb molecules was numerically calculated with the help of the Poisson-Boltzmann equation at pH 6.2 and an ionic strength of 100 mmol/l. Based on experimental and theoretical studies of the mechanism of the interaction of the polyelectrolyte with the proteins, the structural-functional properties of proteins responsible for their destruction by the polyelectrolyte are determined.

  15. Fluorescent Polystyrene Microbeads as Invisible Security Ink and Optical Vapor Sensor for 4-Nitrotoluene.

    Science.gov (United States)

    Sonawane, Swapnil L; Asha, S K

    2016-04-27

    Color-tunable solid-state emitting polystyrene (PS) microbeads were developed by dispersion polymerization, which showed excellent fluorescent security ink characteristics along with sensitive detection of vapors of nitro aromatics like 4-nitro toluene (4-NT). The fluorophores pyrene and perylenebisimide were incorporated into the PS backbone as acrylate monomer and acrylate cross-linker, respectively. Solid state quantum yields of 94 and 20% were observed for the pyrene and perylenebisimide, respectively, in the PS/Py and PS/PBI polymers. The morphology and solid state fluorescence was measured by SEM, fluorescence microscopy, and absorbance and fluorescence spectroscopy techniques. The ethanol dispersion of the polymer could be used directly as a fluorescent security "invisible" ink, which became visible only under ultraviolet light. The color of the ink could be tuned depending on the amounts of the pyrene and perylenebisimide incorporated with blue and orange-green for pyrene alone or perylenebisimide alone beads respectively and various shades in between including pure white for beads incorporating both the fluorophores. More than 80% quenching of pyrene emission was observed upon exposure of the polymer in the form of powder or as spin-coated films to the vapors of 4-NT while the emission of perylenebisimide was unaffected. The limit of detection was estimated at 10(-5) moles (2.7 ppm) of 4-NT vapors. The ease of synthesis of the material along with its invisible ink characteristics and nitro aromatic vapor detection opens up new opportunities for exploring the application of these PS-based materials as optical sensors and fluorescent ink for security purposes.

  16. Coupling of carboxylic groups onto the surface of polystyrene parts during fused filament fabrication

    Science.gov (United States)

    Nagel, Jürgen; Zimmermann, Philipp; Schubert, Oliver; Simon, Frank; Schlenstedt, Kornelia

    2017-11-01

    A method for the fabrication of polystyrene parts, modified with carboxylic groups during Fused Filament Fabrication (FFF), is being introduced. This method is based on the application of a thin layer of a reactive polymer carrying carboxylic groups on a substrate surface. A polystyrene film is printed on top of this layer. During contact between the hot melt and the reactive layer, a Friedel-Crafts type acylation using a green catalyst takes place, which attaches the reactive polymer to the polystyrene surface. The modified surface is homogeneous, hydrophilic and able to bind copper ions. The method could be used to fabricate unique parts of polystyrene with tailored surface functionalisation. It could be applied for laboratory use, e.g. for the manufacture of lab-on-a-chip devices.

  17. APPLICATION OF POLYSTYRENE FOAM CORE FUSIBLE PATTERNS IN PRODUCTION OF GAS TURBINES’ CAST PARTS

    Directory of Open Access Journals (Sweden)

    O. I. Shinsky

    2016-01-01

    Full Text Available The task of replacing the LVM dissolves polystyrene molding on models is at the present time, technologically, economically and environmentally promising from the point of view of industrial applications for gas turbine plants in Ukraine. The authors proposed and tested manufacturing process of casting ceramic molds way to remove the polystyrene model of the dissolution of her organic solvents. Kinetic parameters of the process of dissolving and removing patterns of degradation products the polystyrene in the group of solvents depending on the type and amount of polystyrene were identified. The absence of surface defects of castings, reduction of roughness, increased their accuracy class in comparison to accepted technological regulations of the process of production, which reduced the cost of machined parts and increased utilization of expensive heat-resistant alloys were produced.

  18. Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test

    DEFF Research Database (Denmark)

    Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva

    1996-01-01

    A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS......-PAGE and Western blotting, A total of 205 A. pleuropneumoniae, strains including all 12 serotype reference strains and 13 strains representing 8 common bacterial species associated with swine or related to A, pleuropneumoniae, were tested by mixing 25 mu L of polystyrene reagent with the same volume of a dense...... suspension of bacterial cells grown for 18 h. All A, pleuropneumoniae strains had been previously serotyped using standard procedures, The polystyrene agglutination test was rapid (less than 3 min) and easy to perform. Overall a very good correlation (97.3%) with the standard techniques was found...

  19. Dynamic characteristics and seismic stability of expanded polystyrene geofoam embankments

    Science.gov (United States)

    Amini, Zahra A.

    Expanded Polystyrene (EPS) geofoam has become a preferred material in various construction applications due to its light weight. Application of EPS accelerates the projects particularly on soft soils. The focus of this research is on the application of the EPS in embankments and its behavior mainly under harmonic vibration. The goal of this study was to investigate dynamic characteristics of freestanding vertical EPS geofoam embankment and address potential seismic issues that result from the distinguished dynamic behavior of such systems due to the layered and discrete block structure. A series of experimental studies on EPS 19 and a commercially available adhesive was conducted. Two-dimensional numerical analyses were performed to replicate the response of EPS geofoam embankment to horizontal and vertical harmonic motions. The results of the analyses have shown that for some acceleration amplitude levels interlayer sliding is expected to occur in EPS geofoam embankments almost immediately after the start of the base excitation; however, as a highly efficient energy dissipation mechanism sliding ceases rapidly. Shear keys and adhesive may be used to prevent interlayer sliding if they cover the proper extent of area of the embankment. EPS blocks placed in the corners of the embankment and at the edges of the segment prohibited from sliding may experience high stress concentrations. The embankment may show horizontal sway and rocking once sliding is prevented.

  20. Deterioration of expanded polystyrene caused by Aureobasidium pullulans var. melanogenum.

    Science.gov (United States)

    Castiglia, Valeria C; Kuhar, Francisco

    2015-01-01

    An expanded-polystyrene factory located in northern Buenos Aires reported unusual dark spots causing esthetic damage in their production. A fungal strain forming black-olive colonies on extract malt agar medium was isolated from the damaged material and identified as Aureobasidium pullullans var. melanogenum. This fungus is particularly known for its capacity to produce hydrolytic enzymes and a biodegradable extracellular polysaccharide known as pullulan, which is used in the manufacture of packaging material for food and medicine. Laboratory tests were conducted to characterize its growth parameters. It was found that the organism was resistant to a wide range of pHs but did not survive at temperatures over 65°C. The proposed action plan includes drying of the material prior to packaging and disinfection of the machinery used in the manufacturing process and of the silos used for raw material storage. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Characterization of crosslinked polystyrene(PS) beads in SBR matrix

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Yoon-Jong; Choe, Soonja [Inha Univ. (Korea, Republic of)

    1995-12-01

    Monodisperse sized crosslinked polystyrene(PS) beads were prepared by a reaction of semibatch emulsion polymerization with styrene monomer, divinylbenzene(DVB) crosslinking agent and potassium persulfate(K{sub 2}S{sub 2}O{sub 9}) initiator in the absence of emulsifier. The glass transition temperature(T{sub g}) and the mean diameter of the beads were increased from 100{degrees}C to 135{degrees}C and from 402 nm to 532 nm, respectively, for an incorporation of 2 to 10 mol% DVB. Crosslinking density was also linearly increased with DVB content. SEM microphotographs of SBR composite filled with various contents of PS beads revealed that PS beads are relatively well dispersed without changing the spherical shape of the beads in all range of compositions. In stress-strain analysis, elongation at break and tensile strength of SBR composite were increased with the bead content. Applicability of the PS beads as a filler in SBR matrix is tested by plotting Mooney-Rivlin or Guth-Smallwood equations. However, mechanical properties of the composite with the beads were not so excellent as those of the composite with carbon black. Crosslinked PS beads are still tentative as a white color reinforcing filler on SBR matrix.

  2. A PRESSURE-BUBBLE VACUUM FORMING PROCESS FOR POLYSTYRENE SHEET

    Directory of Open Access Journals (Sweden)

    Emil Sasimowski

    2017-06-01

    Full Text Available The paper reports the results of a study on the effect of selected conditions of a pressure-bubble vacuum forming for polystyrene sheet on the non-uniformity of wall thickness of finished parts. The investigation was performed using DOE methods. Variables for the tests included temperatures in the external and internal zones of the heaters as well as heating time. The results demonstrate that the heating time and temperature in the internal zone formed by the heater have a statistically significant effect on the finished part’s wall thickness at the measuring points. It has been found that the side walls and bottom of the finished part are uniformly deformed, and thus exhibit the lowest wall thickness non-uniformity at a heating time of 22s (corresponding to the middle of the measuring range. Also, it is observed that the application of low temperatures in both zones of the heater has a positive effect. Due to the use of bubble, the finished parts exhibit a much lower wall thickness non-uniformity compared to those produced without bubble.

  3. Role of electric field on surface wetting of polystyrene surface.

    Science.gov (United States)

    Bhushan, Bharat; Pan, Yunlu

    2011-08-02

    The role of surface charge in fluid flow in micro/nanofluidics systems as well as the role of electric field to create switchable hydrophobic surfaces is of interest. In this work, the contact angle (CA) and contact angle hysteresis (CAH) of a droplet of deionized (DI) water were measured with applied direct current (DC) and alternating current (AC) electric fields. The droplet was deposited on a polystyrene (PS) surface, commonly used in various nanotechnology applications, coated on a doped silicon (Si) wafer. With the DC field, CA decreased with an increase in voltage. Because of the presence of a silicon oxide layer and a space charge layer, the change of the CA was found to be lower than with a metal substrate. The CAH had no obvious change with a DC field. An AC field with a positive value was applied to the droplet to study its effect on CA and CAH. At low frequency (lower than 10 Hz), the droplet was visibly oscillating. The CA was found to increase when the frequency of the applied AC field increased from 1 Hz to 10 kHz. On the other hand, the CA decreased with an increasing peak-peak voltage at or lower than 10 kHz. The CAH in the AC field was found to be lower than in the DC field and had a similar trend to static CA with increasing frequency. A model is presented to explain the data.

  4. Photoluminescence properties of polystyrene-hosted fluorophore thin films

    Directory of Open Access Journals (Sweden)

    Subha Chakraborty

    2016-12-01

    Full Text Available We report on a photo-luminescence study of four different fluorophores: Coumarin 6, 2,5-Diphenyloxazole (PPO, 1,4-Bis(5-phenyl-2-oxazolylbenzene (POPOP and Para-terpehnyl (PTP, doped in a polystyrene-based thin film. All of the samples are prepared by spin coating from a non-polar polymer solution at various concentrations. Their emission spectra and transient properties are characterized by photoluminescence measurements. Red-shifts in the emission spectra are observed for all four types of fluorophores as their concentration increases. We explain this phenomenon based on concentration dependence of solvatochromic effects and the results show good agreement with existing literature. We also show that the singlet-singlet annihilation processes are possibly a prevalent mechanism in the high concentration regime that affects the steady state and transient emission characteristics of the fluors. With the exception of PTP, photoluminescence quenching occurs as the fluorophore concentration in the polymer is increased. Rate equations for excited state decay mechanisms are analysed by considering different radiative and non-radiative energy transfer mechanisms. The results show consistency with our experimental observations. PTP shows the best photoluminescence results as an efficient fluor in the thin film, whereas PPO shows the strongest concentration dependent quenching and an anomalous lifetime distribution.

  5. Metal-Containing Polystyrene Beads as Standards for Mass Cytometry.

    Science.gov (United States)

    Abdelrahman, Ahmed I; Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Kinach, Robert; Dai, Sheng; Thickett, Stuart C; Tanner, Scott; Winnik, Mitchell A

    2010-01-01

    We examine the suitability of metal-containing polystyrene beads for the calibration of a mass cytometer instrument, a single particle analyser based on an inductively coupled plasma ion source and a time of flight mass spectrometer. These metal-containing beads are also verified for their use as internal standards for this instrument. These beads were synthesized by multiple-stage dispersion polymerization with acrylic acid as a comonomer. Acrylic acid acts as a ligand to anchor the metal ions within the interior of the beads. Mass cytometry enabled the bead-by-bead measurement of the metal-content and determination of the metal-content distribution. Beads synthesized by dispersion polymerization that involved three stages were shown to have narrower bead-to-bead variation in their lanthanide content than beads synthesized by 2-stage dispersion polymerization. The beads exhibited insignificant release of their lanthanide content to aqueous solutions of different pHs over a period of six months. When mixed with KG1a or U937 cell lines, metal-containing polymer beads were shown not to affect the mass cytometry response to the metal content of element-tagged antibodies specifically attached to these cells.

  6. Trityl-derivatized carbohydrates immobilized on a polystyrene microplate.

    Science.gov (United States)

    Zou, Lan; Pang, Hei-Leung; Chan, Pak-Ho; Huang, Zhi-Shu; Gu, Lian-Quan; Wong, Kwok-Yin

    2008-11-24

    Carbohydrate biosensors, including carbohydrate arrays, are attracting increased attention for the comprehensive and high-throughput investigation of protein-carbohydrate interactions. Here, we describe an effective approach to fabricating a robust microplate-based carbohydrate array capable of probing protein binding and screening for inhibitors in a high-throughout manner. This approach involves the derivatization of carbohydrates with a trityl group through an alkyl linker and the immobilization of the trityl-derivatized carbohydrates (mannose and maltose) onto microplates noncovalently to construct carbohydrate arrays. The trityl carbohydrate derivative has very good immobilization efficiency for polystyrene microplates and strong resistance to aqueous washing. The carbohydrate arrays can probe the interactions with the lectin Concanavalin A and screen this protein for the well-known inhibitors methyl alpha-D-mannopyranoside and methyl alpha-D-glucopyranoside in a high-throughput manner. The method described in this paper represents a convenient way of fabricating robust noncovalent carbohydrate arrays on microplates and offers a convenient platform for high-throughput drug screening.

  7. Femtosecond laser-induced surface wettability modification of polystyrene surface

    Science.gov (United States)

    Wang, Bing; Wang, XinCai; Zheng, HongYu; Lam, YeeCheong

    2016-12-01

    In this paper, we demonstrated a simple method to create either a hydrophilic or hydrophobic surface. With femtosecond laser irradiation at different laser parameters, the water contact angle (WCA) on polystyrene's surface can be modified to either 12.7° or 156.2° from its original WCA of 88.2°. With properly spaced micro-pits created, the surface became hydrophilic probably due to the spread of the water droplets into the micro-pits. While with properly spaced micro-grooves created, the surface became rough and more hydrophobic. We investigated the effect of laser parameters on WCAs and analyzed the laser-treated surface roughness, profiles and chemical bonds by surface profilometer, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). For the laser-treated surface with low roughness, the polar (such as C—O, C=O, and O—C=O bonds) and non-polar (such as C—C or C—H bonds) groups were found to be responsible for the wettability changes. While for a rough surface, the surface roughness or the surface topography structure played a more significant role in the changes of the surface WCA. The mechanisms involved in the laser surface wettability modification process were discussed.

  8. Characterization of Fluorescent Polystyrene Microspheres for Advanced Flow Diagnostics

    Science.gov (United States)

    Maisto, Pietro M. F.; Lowe, K. Todd; Byun, Guibo; Simpson, Roger; Vercamp, Max; Danley, Jason E.; Koh, Brian; Tiemsin, Pacita; Danehy, Paul M.; Wohl, Christopher J.

    2013-01-01

    Fluorescent dye-doped polystyrene latex microspheres (PSLs) are being developed for velocimetry and scalar measurements in variable property flows. Two organic dyes, Rhodamine B (RhB) and dichlorofluorescence (DCF), are examined to assess laser-induced fluorescence (LIF) properties for flow imaging applications and single-shot temperature measurements. A major interest in the current research is the application of safe dyes, thus DCF is of particular interest, while RhB is used as a benchmark. Success is demonstrated for single-point laser Doppler velocimetry (LDV) and also imaging fluorescence, excited via a continuous wave 2 W laser beam, for exposures down to 10 ms. In contrast, when exciting with a pulsed Nd:YAG laser at 200 mJ/pulse, no fluorescence was detected, even when integrating tens of pulses. We show that this is due to saturation of the LIF signal at relatively low excitation intensities, 4-5 orders of magnitude lower than the pulsed laser intensity. A two-band LIF technique is applied in a heated jet, indicating that the technique effectively removes interfering inputs such as particle diameter variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about +/-12.5 C precision, while future improvements in dye temperature sensitivity and signal quality may enable single-shot temperature measurements with sub-degree precision.

  9. Interchain tube pressure effect in extensional flows of oligomer diluted nearly monodisperse polystyrene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Huang, Qian

    2014-01-01

    times and entanglements have been established based on published extensional experiments on nearly monodisperse polystyrene melts. The constitutive equation has shown agreement with the experimental startup of and steady extension data from Huang et al. (Macromolecules 46:5026–5035, 2013a) based on 285...... and 545 kg/mol polystyrenes diluted in styrene oligomers containing 3.3 (1.92 kg/mol) and 7.3 (4.29 kg/mol) Kuhn steps....

  10. Epithelial wound healing on keratin film, amniotic membrane and polystyrene in vitro.

    Science.gov (United States)

    Feng, Yaqing; Borrelli, Maria; Meyer-Ter-Vehn, Tobias; Reichl, Stephan; Schrader, Stefan; Geerling, Gerd

    2014-06-01

    Corneal epithelial wound healing is a major issue in ocular surface (OS) reconstruction. Aim of this study was to evaluate parameters of epithelial wound healing in vitro on transparent keratin films (KFs) derived from human hair in comparison with amniotic membrane (AM) and polystyrene. The human corneal epithelial cell line (HCE-T) was expanded on KF, AM and commercially available 24-well polystyrene cell culture plates in vitro to compare cell proliferation, migration and attachment by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, scratch-wound healing and adhesion assay. Cells cultured on KF and AM at an air-liquid interface for 14 d were stained with hematoxylin and eosin for histology. The highest proliferation of HCE-T cells was observed on polystyrene at all time points (p polystyrene at all time points (p polystyrene and KF (p = 0.032 and p = 0.001). No significant difference in cell attachment was observed between KF and polystyrene (p = 0.147). Histology demonstrated that HCE-T cells cultured on KF and AM at an air-liquid interface for 14 d form a multilayered epithelium similar to normal human corneal epithelium. Transparent KFs derived from human hair support proliferation, migration, adhesion and differentiation of HCE-T cells in vitro. Therefore, it could be a promising alternative to AM for OS reconstruction.

  11. Biodegradation of polystyrene-graft-starch copolymers in three different types of soil.

    Science.gov (United States)

    Nikolic, Vladimir; Velickovic, Sava; Popovic, Aleksandar

    2014-01-01

    Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30%). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93%), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77%) that is preventing biodegradation of degradable part of copolymers.

  12. Miscibility, crystallization and mechanical properties of biodegradable blends of poly(L-lactic acid) and poly(butylene succinate-b-ethylene succinate) multiblock copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Ling; Huang, Cai-Li [Center for Degradable and Flame-Retardant Polymeric Materials, College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Zeng, Jian-Bing, E-mail: zengjianbing@scu.edu.cn [Center for Degradable and Flame-Retardant Polymeric Materials, College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Wang, Yu-Zhong [Center for Degradable and Flame-Retardant Polymeric Materials, College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China); Wang, Xiu-Li, E-mail: xiuliwang1@163.com [Center for Degradable and Flame-Retardant Polymeric Materials, College of Chemistry, State Key Laboratory of Polymer Materials Engineering, National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), Sichuan University, Chengdu 610064 (China)

    2012-07-10

    Highlights: Black-Right-Pointing-Pointer The blend of PLLA and PBES showed limited miscibility. Black-Right-Pointing-Pointer The crystallization rate of PLLA was accelerated by blending with PBES. Black-Right-Pointing-Pointer The crystal structures of PLLA and PBES did not change. - Abstract: Poly(L-lactic acid) (PLLA) is regarded as one of the most promising biobased and biodegradable polymers. However, its application was restricted due to the brittle nature. In the present study, PLLA was blended with a novel biodegradable flexible multiblock copolymer, poly(butylene succinate-b-ethylene succinate) (PBES) to produce new biodegradable materials. PLLA/PBES blends with different composition were prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility, crystallization behavior, and mechanical properties of the blends were investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and tensile tests. The results indicated that PLLA and PBES showed limited miscibility in the amorphous phase. The crystallization rate of PLLA was accelerated with the increase of PBES in the blends while the crystallization mechanism did not change. The results of tensile tests suggest that the blends showed longer elongation at break than neat PLLA. The elongation at break of PLLA was obtained to be 10%, and those of PLLA/PBES 80/20, 60/40, 40/60 and 20/80 were 29, 110, 442, and 455%, respectively.

  13. Investigation on Polylactide (PLA/Poly(butylene adipate-co-terephthalate (PBAT/Bark Flour of Plane Tree (PF Eco-Composites

    Directory of Open Access Journals (Sweden)

    Qiang Dou

    2016-05-01

    Full Text Available Polylactide (PLA/poly(butylene adipate-co-terephthalate (PBAT/bark flour of plane tree (PF eco-composites were prepared via melt blending. The morphologies, mechanical properties, crystal structures and melting and crystallization behaviors of the eco-composites were investigated by means of scanning electron microscopy (SEM, mechanical tests, polarized light microscopy (PLM, wide angle X-ray diffraction (WAXD and differential scanning calorimetry (DSC, respectively. It is shown that the interfacial adhesion between PLA matrix and PF is weak and the mechanical properties of PLA/PF eco-composites are poor. The titanate treatment improves the adhesion between the matrix and the filler and enhances the stiffness of the eco-composites. The toughness is improved by PBAT and ductile fractured surfaces can be found. The spherulitic size of PLA is decreased by the addition of PF. The α crystalline form of PLA remains in the composites. Compared with PF, T-PF (PF treated by a titanate coupling agent and PBAT have negative effects on the crystallization of PLA.

  14. How Stress Treatments Influence the Performance of Biodegradable Poly(Butylene Succinate-Based Copolymers with Thioether Linkages for Food Packaging Applications

    Directory of Open Access Journals (Sweden)

    Valentina Siracusa

    2017-08-01

    Full Text Available Biodegradable poly(butylene succinate (PBS-based random copolymers containing thioether linkages (P(BSxTDGSy of various compositions have been investigated and characterized from the gas barrier, thermal, and mechanical point of view, after food contact simulants or thermal and photoaging processes. Each stress treatment was performed on thin films and the results obtained have been compared to the same untreated film, used as a standard. Barrier properties with different gases (O2 and CO2 were evaluated, showing that the polymer chemical composition strongly influenced the permeability behavior. The relationships between the diffusion coefficients (D and solubility (S with polymer composition were also investigated. The results highlighted a correlation between polymer chemical structure and treatment. Gas transmission rate (GTR mainly depending on the performed treatment, as GTR increased with the increase of TDGS co-unit amount. Thermal and mechanical tests allowed for the recording of variations in the degree of crystallinity and in the tensile properties. An increase in the crystallinity degree was recorded after contact with simulant liquids and aging treatments, together with a molecular weight decrease, a slight enhancement of the elastic modulus and a decrement of the elongation at break, proportional to the TDGS co-unit content.

  15. Investigation on sodium benzoate release from poly(butylene adipate-co-terephthalate)/organoclay/sodium benzoate based nanocomposite film and their antimicrobial activity.

    Science.gov (United States)

    Mondal, Dibyendu; Bhowmick, Biplab; Maity, Dipanwita; Mollick, Md Masud R; Rana, Dipak; Rangarajan, Vivek; Sen, Ramkrishna; Chattopadhyay, Dipankar

    2015-03-01

    Polymeric nanocomposites embedded with nontoxic antimicrobial agents have recently gained potential industrial significance, mainly for their applicability to preserve food quality and ensure safety. In this study, a poly(butylene adipate-co-terephthalate) (PBAT)/organoclay (CMMT) based nanocomposite film doped with sodium benzoate (SB) as antimicrobial agent was prepared by a solution mixing process. A homogenous dispersion of organoclay (cetyltrimethylammonium-modified montmorillonite [CMMT]) in PBAT matrix was observed by X-ray diffraction and transmission electron microscopy. PBAT/CMMT nanocomposite film showed higher barrier properties against water and methanol vapor compared to the PBAT film. The release of SB from PBAT and its nanocomposite film was measured and the relevant data were fitted to the Weibull model. The higher values of Weibull's shape factor and scale parameter as corroborated by experimental findings indicated faster rate of SB release from PBAT/CMMT/SB nanocomposite film, when compared to the pristine PBAT film. Bacterial inhibition studies were accomplished against 2 food pathogenic bacteria, Bacillus subtilis and Staphylococcus aureus, by determining the zone of inhibition and corresponding growth profiles. Both bacterial inhibition studies and growth profiles established that PBAT/CMMT/SB demonstrated better antimicrobial activity than PBAT/SB film. Therefore, PBAT/CMMT/SB nanocomposite film can be used for food packaging application as it showed good barrier properties and antimicrobial activity against food pathogenic bacteria. © 2015 Institute of Food Technologists®

  16. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly[(butylene succinate)-co-adipate] blend composites.

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-05-01

    Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content. Thermal analysis revealed that crystallinity was dependent on the clay content as well its localization within the composite. On the other hand, thermal stability marginally improved for composites with 2 wt %. Tensile properties showed dependence on clay content and localization. Composite with 2 wt % clay content showed slight improvement in elongation at break. Overall, the optimum property was found for a composite with 2 wt % of the organoclay. This paper therefore has demonstrated the significance of the clay content and localization on the properties of the PLA/PBSA blends.

  17. Role of specific interfacial area in controlling properties of immiscible blends of biodegradable polylactide and poly[(butylene succinate)-co-adipate].

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-12-01

    Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fourier-transform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM). SEM micrographs showed that PLA-rich blends had smaller droplet sizes when compared to the PBSA-rich blends, which got smaller with the reduction in PBSA content due to the differences in their melt viscosities. The interfacial area of PBSA droplets per unit volume of the blend reached a maximum in the 70PLA/30PBSA blend. Thermal stability and mechanical properties were not only affected by the composition of the blend, but also by the interfacial area between the two polymers. Through differential scanning calorimetry, it was shown that molten PBSA enhanced crystallization of PLA while the stiff PLA hindered cold crystallization of PBSA. Optimal synergies of properties between the two polymers were found in the 70PLA/30PBSA blend because of the maximum specific interfacial area of the PBSA droplets.

  18. PAHs in polystyrene food contact materials: An unintended consequence.

    Science.gov (United States)

    Li, Si-Qi; Ni, Hong-Gang; Zeng, Hui

    2017-12-31

    Eight low-ring PAHs were detected in 21 polystyrene (PS) food contact materials (FCMs) samples while high-ring PAHs (>4 rings) were not found. This is because the reaction pathway for formation of high-ring PAHs consists of more steps than it does for low-high PAHs. The concentrations of Σ 8 PAH were from 18.9±5.16ng/g for product colorless fruit fork to 476±52.0ng/g for foam instant noodle container. These data were far beyond levels of PAHs in other plastics. Of the eight PAHs detected, Phe had the highest average concentration, followed by Nap. These two PAHs collectively accounted for over 80% of the Σ 8 PAH concentrations in all PS FCMs. Levels of Σ 8 PAH in expanded PS FCMs were higher than those in extruded ones due to utilization of foaming agent. The concentrations of Σ 8 PAH were lower in colorless PS FCMs than in colored ones. Auxochromes and chromophores contributed to the change of short-chain hydrocarbons to aromatic hydrocarbon. Simulated migration values of PAHs from PS FCMs to food varied widely. The migration value of Σ 8 PAH with maximum probability was below 10ng/g, which the maximum tolerated migration level for substance according to the European Union standards. However, higher migration values were possible and the potential health risk should still be concerned because the simulated migration displayed a log-normal distribution. Furthermore, water was used as food simulant would always lead to an underestimate of PAHs migration to real daily food, and then lead to an underestimate of risk. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Oyster reproduction is affected by exposure to polystyrene microplastics

    Science.gov (United States)

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-01-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L−1) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (−38%), diameter (−5%), and sperm velocity (−23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring. PMID:26831072

  20. Oyster reproduction is affected by exposure to polystyrene microplastics.

    Science.gov (United States)

    Sussarellu, Rossana; Suquet, Marc; Thomas, Yoann; Lambert, Christophe; Fabioux, Caroline; Pernet, Marie Eve Julie; Le Goïc, Nelly; Quillien, Virgile; Mingant, Christian; Epelboin, Yanouk; Corporeau, Charlotte; Guyomarch, Julien; Robbens, Johan; Paul-Pont, Ika; Soudant, Philippe; Huvet, Arnaud

    2016-03-01

    Plastics are persistent synthetic polymers that accumulate as waste in the marine environment. Microplastic (MP) particles are derived from the breakdown of larger debris or can enter the environment as microscopic fragments. Because filter-feeder organisms ingest MP while feeding, they are likely to be impacted by MP pollution. To assess the impact of polystyrene microspheres (micro-PS) on the physiology of the Pacific oyster, adult oysters were experimentally exposed to virgin micro-PS (2 and 6 µm in diameter; 0.023 mg·L(-1)) for 2 mo during a reproductive cycle. Effects were investigated on ecophysiological parameters; cellular, transcriptomic, and proteomic responses; fecundity; and offspring development. Oysters preferentially ingested the 6-µm micro-PS over the 2-µm-diameter particles. Consumption of microalgae and absorption efficiency were significantly higher in exposed oysters, suggesting compensatory and physical effects on both digestive parameters. After 2 mo, exposed oysters had significant decreases in oocyte number (-38%), diameter (-5%), and sperm velocity (-23%). The D-larval yield and larval development of offspring derived from exposed parents decreased by 41% and 18%, respectively, compared with control offspring. Dynamic energy budget modeling, supported by transcriptomic profiles, suggested a significant shift of energy allocation from reproduction to structural growth, and elevated maintenance costs in exposed oysters, which is thought to be caused by interference with energy uptake. Molecular signatures of endocrine disruption were also revealed, but no endocrine disruptors were found in the biological samples. This study provides evidence that micro-PS cause feeding modifications and reproductive disruption in oysters, with significant impacts on offspring.

  1. Mechanism of immunoglobulin G adsorption on polystyrene microspheres.

    Science.gov (United States)

    Sofińska, Kamila; Adamczyk, Zbigniew; Barbasz, Jakub

    2016-01-01

    The adsorption of polyclonal immunoglobulin G (IgG) on negatively charged polystyrene microparticle suspension (latex) was studied by using the Laser Doppler Velocimetry (LDV) measurements. Using this technique, the dependence of the electrophoretic mobility of particles on the IgG concentration in the suspension was measured for various ionic strengths and pH 3.5. The increase in the electrophoretic mobility was quantitatively interpreted in terms of the 3D electrokinetic model. On the other hand, the maximum coverage of IgG on latex was determined using the depletion method based on AFM imaging. It was shown that IgG adsorption was irreversible and that its maximum coverage on the microspheres increased from 1.4mgm(-2) for 0.001M NaCl to 2.0mgm(-2) for 0.15M NaCl. This was interpreted in terms of reduced electrostatic repulsion among adsorbed molecules. The stability of IgG monolayers on the particles was confirmed in separate experiments where changes in its electrophoretic mobility were monitored over prolonged time periods. Additionally, the acid-base properties of the IgG monolayers on latex were determined in pH cycling experiments. The isoelectric point of the IgG monolayers on the microspheres was 4.8. The results obtained in this work indicate that basic physicochemical characteristics of IgG can be acquired via electrophoretic mobility measurements using microgram quantities of the protein. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Efficient functionalization of poly(styrene) beads immobilized metal ...

    Indian Academy of Sciences (India)

    during synthesis in aqueous medium. The recovery of such type of homogeneous catalysts has normally been carried out by dialysis, magnetic separation, precipitation and ultra- centrifugation methods.3 However, again ... through immobilization of protected gold NPs.20 They have been extensively exploited in the area of ...

  3. Transition-Metal-Free Synthesis of 1,3-Butadiene-Containing π-Conjugated Polymers.

    Science.gov (United States)

    Cai, Xuediao; Liu, Yating; Lu, Tian; Yang, Rui; Luo, Chuxin; Zhang, Qi; Chai, Yonghai

    2016-12-01

    This work describes the synthesis of π-conjugated polymers possessing arylene and 1,3-butadiene alternating units in the main chain by the reaction of α,β-unsaturated ester/nitrile containing γ-H with aromatic/heteroaromatic aldehyde compound. By using 4-(4-formylphenyl)-2-butylene acid ethyl ester as a model monomer, the different polymerization conditions, including catalyst, catalyst amount, and solvent, are optimized. The polymerization of 4-(4-formylphenyl)-2-butylene acid ethyl ester is carried out by refluxing in ethanol for 72 h with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst to give a 1,3-butadiene-containing π-conjugated polymer, poly(phenylene-1,3-butadiene), in 84.3% yield with M¯n and M¯w/M¯n (PDI) estimated as 6172 and 1.65, respectively. Based on this new methodology, a series of π-conjugated polymers containing 1,3-butadiene units with different substituents are obtained in high yields. A possible mechanism is proposed for the polymerization through a six-membered ring transition state and then a 1,5-H shift intermediate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Enzyme-catalyzed synthesis of unsaturated aliphatic polyesters based on green monomers from renewable resources.

    Science.gov (United States)

    Jiang, Yi; Woortman, Albert J J; van Ekenstein, Gert O R Alberda; Loos, Katja

    2013-08-12

    Bio-based commercially available succinate, itaconate and 1,4-butanediol are enzymatically co-polymerized in solution via a two-stage method, using Candida antarctica Lipase B (CALB, in immobilized form as Novozyme® 435) as the biocatalyst. The chemical structures of the obtained products, poly(butylene succinate) (PBS) and poly(butylene succinate-co-itaconate) (PBSI), are confirmed by 1H- and 13C-NMR. The effects of the reaction conditions on the CALB-catalyzed synthesis of PBSI are fully investigated, and the optimal polymerization conditions are obtained. With the established method, PBSI with tunable compositions and satisfying reaction yields is produced. The 1H-NMR results confirm that carbon-carbon double bonds are well preserved in PBSI. The differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) results indicate that the amount of itaconate in the co-polyesters has no obvious effects on the glass-transition temperature and the thermal stability of PBS and PBSI, but has significant effects on the melting temperature.

  5. The use of polystyrene-tethered fullerenes as stabilizers in bulk heterojunctions

    Science.gov (United States)

    Moore, Joshua Alexander

    Self-assembly of nanoparticles can potentially provide improvements for many current applications and could influence the design of future technologies. The assembly of nanoparticles, which can be controlled through external forces or through molecular interactions, can affect the properties of a material. Nanoparticles can be chemically modified by attaching molecules such as polymers to their surface. The nature and placement of these tethers affects the arrangement of the nanoparticles leading to materials with novel chemical, electrical, and physical properties. In this research, the assembly of the fullerene (C60) based nanoparticles was modified using polystyrene-tethered fullerenes (PTFs) as additives. Polystyrene (PS) was synthesized via atom transfer radical polymerization and fully characterized by GPC and IR. The PS was attached to C60 using atom transfer radical addition, azide coupling, and by the addition of CN- to the C60 creating a nucleophile that reacted with bromine terminated PS. PTFs were characterized using GPC with a UV-Vis detector and TGA to determine percent C60. This study focuses on the synthesis and characterization of PTFs and the use of PTFs as an additive in organic photovoltaics (OPVs). The size of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) domains within the bulk heterojunction (BHJ) of OPVs is of great importance to the performance and lifetime of the device. PTFs were used as an additive in the BHJ to reduce the initial PCBM domain size as well as to mitigate the growth of these domains over time that typically results in decreased device efficiency. Films were prepared from a mixture of PCBM:P3HT on silicon wafers to approximate a BHJ system. PTFs were added in concentrations ranging from 0% to 20%. The samples were then annealed at 150°C for varying times ranging from 5 to 60 mins and examined by SEM to determine the average PCBM domain sizes for each sample. As expected, the control sample containing no additive showed

  6. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    OpenAIRE

    Yin-lin Lei; Yun-jie Luo; Fei Chen; Le-he Mei

    2014-01-01

    With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF) alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN) cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB) in the alloy particles on the...

  7. Synthesis and Characterization of Zinc Borate Nanowhiskers and Their Inflaming Retarding Effect in Polystyrene

    OpenAIRE

    Pingqiang Gao; Yan Zhang

    2015-01-01

    Zinc borate nanowhiskers 4ZnO·B2O3·H2O were in situ successfully synthesized via one-step precipitation reaction. A set of experiments was performed to evaluate the influence of reaction temperature. Increasing the temperature up to 70°C led to the high purity of zinc borate nanowhiskers with a monoclinic crystal structure measuring 50 nm to 100 nm in diameter and approximately 1 µm in length. However, higher temperature decreases the crystallization due to the emergence of other styles of zi...

  8. Synthesis of Polystyrene-Based Random Copolymers with Balanced Number of Basic or Acidic Functional Groups

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2010-01-01

    by copper-catalyzed 1,3 cycloaddition of aliphatic sulfonate- or amine-contaning azides. Both synthetic approaches proved to be highly efficient as evidenced by H-1-NMR analyses. The thermal properties were evaluated by differential scanning calorimetry and thermal gravimetric analyses and were influenced...

  9. Synthesis of soft shell poly(styrene) colloids for filtration experiments

    DEFF Research Database (Denmark)

    Hinge, Mogens

    these structures influence the filtration dewatering characteristic of organic materials. One of the structures that have been identified to affect the filtration dewatering behavior of activated sludge is the amount of extracellular polymer substance (EPS). EPS is a water swollen material and it has been shown...... that the more EPS the larger resistance to filtration. It is difficult to access the influence of water swollen material (as EPS) on the filtration dewatering of activated sludge by performing filtration dewatering experiments on activated sludge. A reason for this is that activated sludge is a physical...... and chemical complex material that is biological active. It is therefore difficult to extract the effect from one single material parameter as the effect from the amount or type of water swollen material from filtration dewatering experiments performed on activated sludge. Substituting the complex organic...

  10. Low-voltage bendable pentacene thin-film transistor with stainless steel substrate and polystyrene-coated hafnium silicate dielectric.

    Science.gov (United States)

    Yun, Dong-Jin; Lee, Seunghyup; Yong, Kijung; Rhee, Shi-Woo

    2012-04-01

    The hafnium silicate and aluminum oxide high-k dielectrics were deposited on stainless steel substrate using atomic layer deposition process and octadecyltrichlorosilane (OTS) and polystyrene (PS) were treated improve crystallinity of pentacene grown on them. Besides, the effects of the pentacene deposition condition on the morphologies, crystallinities and electrical properties of pentacene were characterized. Therefore, the surface treatment condition on dielectric and pentacene deposition conditions were optimized. The pentacene grown on polystyrene coated high-k dielectric at low deposition rate and temperature (0.2-0.3 Å/s and R.T.) showed the largest grain size (0.8-1.0 μm) and highest crystallinity among pentacenes deposited various deposition conditions, and the pentacene TFT with polystyrene coated high-k dielectric showed excellent device-performance. To decrease threshold voltage of pentacene TFT, the polystyrene-thickness on high-k dielectric was controlled using different concentration of polystyrene solution. As the polystyrene-thickness on hafnium silicate decreases, the dielectric constant of polystyrene/hafnium silicate increases, while the crystallinity of pentacene grown on polystyrene/hafnium silicate did not change. Using low-thickness polystyrene coated hafnium silicate dielectric, the high-performance and low voltage operating (1 × 10(4)) and complementary inverter (DC gains, ~20) could be fabricated.

  11. Trichomonas vaginalis clinical isolates: cytoadherence and adherence to polystyrene, intrauterine device, and vaginal ring.

    Science.gov (United States)

    Dos Santos, Odelta; Rigo, Graziela Vargas; Macedo, Alexandre José; Tasca, Tiana

    2017-12-01

    The parasitism by Trichomonas vaginalis is complex and in part is mediated by cytoadherence accomplished via five surface proteins named adhesins and a glycoconjugate called lipophosphoglycan (TvLPG). In this study, we evaluated the ability of T. vaginalis isolates to adhere to cells, plastic (polystyrene microplates), intrauterine device (IUD), and vaginal ring. Of 32 T. vaginalis isolates, 4 (12.5%) were strong adherent. The T. vaginalis isolates TV-LACM6 and TV-LACM14 (strong polystyrene-adherent) were also able to adhere to IUD and vaginal ring. Following chemical treatments, results demonstrated that the T. vaginalis components, lipophosphoglycan, cytoskeletal proteins, and surface molecules, were involved in both adherence to polystyrene and cytoadherence. The gene expression level from four adhesion proteins was highest in trophozoites adhered to cells than trophozoites adhered to the abiotic surface (polystyrene microplate). Our data indicate the major involvement of TvLPG in adherence to polystyrene, and that adhesins are important for cytoadherence. Furthermore, to our knowledge, this is the first report showing the T. vaginalis adherence to contraceptive devices, reaffirming its importance as pathogen among women in reproductive age.

  12. Effect of Surface Modification of Nanosilica on the Viscoelastic Properties of Its Polystyrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    M. Mortezaei

    2008-12-01

    Full Text Available The preparation and characterization of the vinyltriethoxysilane-modified silica nanoparticles were investigated. Also the surface tension of polystyrene, native (hydrophilic silica and silane-modified (hydrophobic silica were determined. Two kinds of polystyrene/silica (treated and non-treated nanocomposites were prepared with different filler loadings by solution method. Their viscoelastic properties were studied by dynamic stress controlled rotary shear rheometer. Solid-like response of polystyrene/native silica nanocomposites were observed in the terminal zone. Solid inclusionsincrease the storage modulus more than the loss modulus, hence decrease the material damping. By increasing filler volume fraction, the particles tend to agglomerate and build clusters. The presence of clusters increases the viscosity, the moduli and the viscoelastic non-linearity of the composites.Treating the filler surface reduces its tendency to agglomerate as well as the adhesion between the particles and the polystyrene, leading to lower viscosity and interfacial slippage. Also the loss modulus peak is affected significantly by the particle surface area and its surface property in silica-filled polystyrene, which corresponds to its glass transition.

  13. Chondrocyte behavior on nanostructured micropillar polypropylene and polystyrene surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Prittinen, Juha [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Jiang, Yu [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Ylärinne, Janne H. [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Pakkanen, Tapani A. [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Lammi, Mikko J., E-mail: mikko.lammi@uef.fi [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Qu, Chengjuan [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland)

    2014-10-01

    This study was aimed to investigate whether patterned polypropylene (PP) or polystyrene (PS) could enhance the chondrocytes' extracellular matrix (ECM) production and phenotype maintenance. Bovine primary chondrocytes were cultured on smooth PP and PS, as well as on nanostructured micropillar PP (patterned PP) and PS (patterned PS) for 2 weeks. Subsequently, the samples were collected for fluorescein diacetate-based cell viability tests, for immunocytochemical assays of types I and II collagen, actin and vinculin, for scanning electronic microscopic analysis of cell morphology and distribution, and for gene expression assays of Sox9, aggrecan, procollagen α{sub 1}(II), procollagen α{sub 1}(X), and procollagen α{sub 2}(I) using quantitative RT-PCR assays. After two weeks of culture, the bovine primary chondrocytes had attached on both patterned PP and PS, while practically no adhesion was observed on smooth PP. However, the best adhesion of the cells was on smooth PS. The cells, which attached on patterned PP and PS surfaces synthesized types I and II collagen. The chondrocytes' morphology was extended, and an abundant ECM network formed around the attached chondrocytes on both patterned PP and PS. Upon passaging, no significant differences on the chondrocyte-specific gene expression were observed, although the highest expression level of aggrecan was observed on the patterned PS in passage 1 chondrocytes, and the expression level of procollagen α{sub 1}(II) appeared to decrease in passaged chondrocytes. However, the expressions of procollagen α{sub 2}(I) were increased in all passaged cell cultures. In conclusion, the bovine primary chondrocytes could be grown on patterned PS and PP surfaces, and they produced extracellular matrix network around the adhered cells. However, neither the patterned PS nor PP could prevent the dedifferentiation of chondrocytes. - Highlights: • Methods to avoid chondrocyte dedifferentiation would be useful for cartilage

  14. Polyhomologation based on in situ generated Boron-thexyl-silaboracyclic initiating sites: a novel strategy towards the synthesis of polyethylene-based complex architectures

    KAUST Repository

    Zhang, Zhen

    2015-04-10

    A novel strategy, based on the in situ generated Boron-thexyl-silaboracyclic initiating sites for the polyhomologation of dimethylsulfoxonium methylide, has been developed for the synthesis of complex polyethylene-based architectures. As examples, the synthesis of a 4-arm polyethylene star, three (polystyrene)(polyethylene)2 3-miktoarm stars and a PE-branched double graft copolymers are given.

  15. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate Biocomposites

    Directory of Open Access Journals (Sweden)

    Mohamad Zaki AB Rahman

    2012-01-01

    Full Text Available A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate (PBAT, which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB fiber was successfully done by grafting succinic anhydride (SAH onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24% compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA/differential thermogravimetric (DTG thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  16. Novel ether-linkages containing aliphatic copolyesters of poly(butylene 1,4-cyclohexanedicarboxylate) as promising candidates for biomedical applications.

    Science.gov (United States)

    Gigli, Matteo; Lotti, Nadia; Vercellino, Marco; Visai, Livia; Munari, Andrea

    2014-01-01

    A new class of biodegradable and biocompatible poly(butylene 1,4-cyclohexanedicarboxylate) based random copolymers are proposed for biomedical applications. The introduction of ether-oxygen containing BDG sequences along the PBCE macromolecular chain is expected to remarkably improve chain flexibility and surface hydrophilicity due to the presence of highly electronegative oxygen atoms. P(BCExBDGy) copolymers were synthesized by polycondensation. The homopolymer PBCE and three copolymers, namely (P(BCE70BDG30), P(BCE55BDG45) and P(BCE40BDG60)) were characterized from the molecular, thermal, structural and mechanical point of view. Hydrolytic degradation studies in the presence and absence of hog-pancreas lipase were performed under physiological conditions. To evaluate the diffusion profile of small molecules through the polymer matrix, the release behaviour of fluorescein isothiocyanate (FITC) was investigated. For biocompatibility studies, cell adhesion and proliferation of murine fibroblast (L929) and endocrine pancreatic (INS-1) cells were performed on each polymeric film. Results showed that solid-state properties can be tailored by simply varying copolymers' composition. Crystallinity degree and hydrophobicity significantly decreased with the increase of BDG co-unit mol%. Moreover, mechanical properties and biodegradability of PBCE, both depending on crystallinity degree, were remarkably improved: P(BCE40BDG60) showed an elastomeric behaviour with εb over 600% and, as regard to biodegradability, after 98days it lost over 60% of its initial weight if incubated in the presence of the pancreatic lipase. Lastly, the newly developed biomaterials resulted not cytotoxic with both types of cells and could be properly tailored for biomedical applications varying the content of BDG co-unit mol%. © 2013.

  17. The impact of DO and salinity on microbial community in poly(butylene succinate) denitrification reactors for recirculating aquaculture system wastewater treatment.

    Science.gov (United States)

    Deng, Ya-Le; Ruan, Yun-Jie; Zhu, Song-Ming; Guo, Xi-Shan; Han, Zhi-Ying; Ye, Zhang-Ying; Liu, Gang; Shi, Ming-Ming

    2017-12-01

    The interactions between environmental factors and bacterial community shift in solid-phase denitrification are crucial for optimum operation of a reactor and to achieve maximum treatment efficiency. In this study, Illumina high-throughput sequencing was applied to reveal the effects of different operational conditions on bacterial community distribution of three continuous operated poly(butylene succinate) biological denitrification reactors used for recirculating aquaculture system (RAS) wastewater treatment. The results indicated that salinity decreased OTU numbers and diversity while dissolved oxygen (DO) had no obvious influence on OTU numbers. Significant microbial community composition differences were observed among and between three denitrification reactors under varied operation conditions. This result was also demonstrated by cluster analysis (CA) and detrended correspondence analysis (DCA). Hierarchical clustering and redundancy analysis (RDA) was performed to test the relationship between environmental factors and bacterial community compositions and result indicated that salinity, DO and hydraulic retention time (HRT) were the three key factors in microbial community formation. Besides, Simplicispira was detected under all operational conditions, which worth drawing more attention for nitrate removal. Moreover, the abundance of nosZ gene and 16S rRNA were analyzed by real-time PCR, which suggested that salinity decreased the proportion of denitrifiers among whole bacterial community while DO had little influence on marine reactors. This study provides an overview of microbial community shift dynamics in solid-phase denitrification reactors when operation parameters changed and proved the feasibility to apply interval aeration for denitrification process based on microbial level, which may shed light on improving the performance of RAS treatment units.

  18. Osteoconductive bio-based meshes based on Poly(hydroxybutyrate-co-hydroxyvalerate) and poly(butylene adipate-co-terephthalate) blends

    Energy Technology Data Exchange (ETDEWEB)

    Nar, Mangesh; Staufenberg, Gerrit; Yang, Bing [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Robertson, Lesli [Department of Fibers, College of Visual Arts and Design, 1155 Union Circle #305100, Denton, TX 76203-5017 (United States); Patel, Rinkesh H. [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); Varanasi, Venu G., E-mail: vvaranasi@bcd.tamhsc.edu [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); D' Souza, Nandika Anne, E-mail: nandika.dsouza@unt.edu [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Department of Mechanical and Energy Engineering, University of North Texas, 1155 Union Circle # 311098, Denton, TX 76203-5017 (United States)

    2014-05-01

    Poly(butylene adipate-co-terephthalate) (PBAT) and Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) are biopolymers that have the potential to be used in applications of bone healing. In this study, it is hypothesized that the polymer blend has the combined strength and osteoconductivity to support osteoblast collagen formation. PBAT (PBAT 100), and a blend with 20% PHBV (PBAT 80) were extruded in the form of fibers and then knitted in the form of mesh. These were tested in the warp as well as weft direction for the tensile properties; these showed that the weft direction had higher performance than the warp. The individual fibers were kept in phosphate buffered saline (PBS) over the period of 8 weeks and were tested for the storage and loss modulus using a dynamic mechanical analyser (DMA). The results indicated that mechanical relaxation strength showed a decrease and then an increase. In vitro osteoconductivity studies were done by using differentiating osteoblasts (MC3T3-E1 subclone 4 cells). Environmental Scanning Electron Microscopy (ESEM) showed that pre-soaking the samples in α-MEM for two weeks resulted in cell attachment and growth. X-ray diffraction (XRD) was used to determine the change in structure of polymers due to in vitro degradation for two weeks. Raman spectroscopy showed that all scaffolds supported the formation of a collagenous network over the scaffold surfaces. For a combination of knittable manufacturing, mechanical performance and osteoconductivity, blends offer an effective route. - Highlights: • PBAT and PHBV blend can be knitted to form mesh with good mechanical properties. • PBAT and PHBV blend do not show significant weight loss over a period of 8 weeks in PBS. • Osteoblast cell culture was done on these samples. • They support extracellular matrix and growth and hence are osteoconductive.

  19. Novel ether-linkages containing aliphatic copolyesters of poly(butylene 1,4-cyclohexanedicarboxylate) as promising candidates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gigli, Matteo [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Lotti, Nadia, E-mail: nadia.lotti@unibo.it [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Vercellino, Marco [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Visai, Livia [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Department of Occupational Medicine, Ergonomics and Disability, Salvatore Maugeri Foundation, IRCCS, Laboratory of Nanotechnology, Via S. Maugeri 8, 27100 Pavia (Italy); Munari, Andrea [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy)

    2014-01-01

    A new class of biodegradable and biocompatible poly(butylene 1,4-cyclohexanedicarboxylate) based random copolymers are proposed for biomedical applications. The introduction of ether–oxygen containing BDG sequences along the PBCE macromolecular chain is expected to remarkably improve chain flexibility and surface hydrophilicity due to the presence of highly electronegative oxygen atoms. P(BCExBDGy) copolymers were synthesized by polycondensation. The homopolymer PBCE and three copolymers, namely (P(BCE70BDG30), P(BCE55BDG45) and P(BCE40BDG60)) were characterized from the molecular, thermal, structural and mechanical point of view. Hydrolytic degradation studies in the presence and absence of hog-pancreas lipase were performed under physiological conditions. To evaluate the diffusion profile of small molecules through the polymer matrix, the release behaviour of fluorescein isothiocyanate (FITC) was investigated. For biocompatibility studies, cell adhesion and proliferation of murine fibroblast (L929) and endocrine pancreatic (INS-1) cells were performed on each polymeric film. Results showed that solid-state properties can be tailored by simply varying copolymers' composition. Crystallinity degree and hydrophobicity significantly decreased with the increase of BDG co-unit mol%. Moreover, mechanical properties and biodegradability of PBCE, both depending on crystallinity degree, were remarkably improved: P(BCE40BDG60) showed an elastomeric behaviour with ε{sub b} over 600% and, as regard to biodegradability, after 98 days it lost over 60% of its initial weight if incubated in the presence of the pancreatic lipase. Lastly, the newly developed biomaterials resulted not cytotoxic with both types of cells and could be properly tailored for biomedical applications varying the content of BDG co-unit mol%. - Highlights: • Ether–oxygen atoms along PBCE chain as winning strategy to improve its properties • Adjustable solid-state properties of copolymers simply

  20. Cage-like mesoporous organosilicas with isocyanurate bridging groups synthesized by soft templating with poly(ethylene oxide)-poly(butylene oxide)-poly(ethylene oxide) block copolymer.

    Science.gov (United States)

    Grudzien, Rafal M; Blitz, Jonathan P; Pikus, Stanislaw; Jaroniec, Mietek

    2009-05-01

    Ordered large-pore organosilicas with isocyanurate bridging groups were synthesized via co-condensation of tetraethyl orthosilicate (TEOS) and tris[3-(trimethoxysilyl)propyl]isocyanurate (ICS) in the presence of poly(ethylene oxide)-poly(butylene oxide)-poly(ethylene oxide) (EO(39)BO(47)EO(39)) B50-6600 template under acidic conditions. It was shown that the extraction of the B60-5500 triblock copolymer with acidified ethanol solution was insufficient to remove completely the template; however, calcination of as-synthesized and extracted samples under air atmosphere at 200 degrees C, 250 degrees C and 300 degrees C caused not only the removal of the polymer but also a substantial decomposition of the ICS groups. In contrast, the heat treatment of extracted organosilicas at 360 degrees C in flowing nitrogen was able to fully remove the residual template without degradation of the ICS bridging groups. Characterization of the resulting materials by small angle X-ray scattering (SAXS) and X-ray powder diffraction (XRD) revealed that isocyanurate-containing organosilicas have a body-centered cubic symmetry (Im3m). Argon adsorption-desorption isotherms of these organosilicas revealed cage-like mesopores, high surface areas and large pore volumes. The diameters of spherical cages were found to be very uniform in the range of 12-14 nm. A complete removal of triblock copolymer was confirmed by high-resolution thermogravimetry (TG), Fourier transform infrared spectroscopy (FT-IR) and CHNS elemental analysis (EA). The latter showed that the isocyanurate rings are intact in the framework and their loading is up to 1 mmol g(-1). Moreover, these organosilicas were also synthesized using low acid concentration, double amount of polymer and sodium chloride; in this case the template was completely extracted and there was no need for additional heat treatment.

  1. Facile approach in fabricating superhydrophobic ZnO/polystyrene nanocomposite coating

    Science.gov (United States)

    Qing, Yongquan; Zheng, Yansheng; Hu, Chuanbo; Wang, Yong; He, Yi; Gong, Yong; Mo, Qian

    2013-11-01

    In this paper, we report a simple and inexpensive method for fabricating modified-ZnO/polystyrene superhydrophobic surface on the cotton textiles. The surface wettability and topology of coating were characterized by contact angle measurement, Scanning electron microscope and Fourier transform infrared spectrometry. The results showed that the hydrophobic CH3 and CF2 group was introduced into ZnO particles via modification, the ZnO nanoparticles were modified from hydrophilic to hydrophobic. When the weight ratio of modified-ZnO to polystyrene was 7:3, the ZnO/polystyrene composite coating contact angle was 158°, coating surface with hierarchical micro/nano structures. Furthermore, the superhydrophobic cotton texiles have a very extensive application prospect in water-oil separation.

  2. Elongational Dynamics of Narrow Molar Mass Distribution Linear and Branched Polystyrene Melts

    Science.gov (United States)

    Rasmussen, Henrik Koblitz; Skov, Anne Ladegaard; Nielsen, Jens Kromann; Laille, Philippe; Hassager, Ole

    2008-07-01

    The startup of uni-axial elongational flow followed by stress relaxation as well as reversed bi-axial flow has been measured for narrow molar mass distribution (NMMD) linear (Mw = 145 kg/mole) and branched multi-arm polystyrene melts, using the filament stretching rheometer. The branched polystyrene melt was a multiarm An-C-C-An pom-pom polystyrene with an estimated average number of arms of n = 2.5. The molar mass of each arm is about 28 kg/mole with an overall molar mass of Mw = 280 kg/mole. The principle of time-strain separability fails completely to describe the dynamic elongation data. Similarly the Doi-Edwards model with any `stretch evolution' equation is not capable of capturing the reversed dynamic of NMMD melts. An integral molecular stress function constitutive formulation within the `interchain pressure' concept, seem to agree with all experiments for linear melts.

  3. Comparison anti-bacterial effect of silver/polystyrene nanocomposites on gram negative and positive bacteria

    Science.gov (United States)

    Kazemi, Akhtarolmolook; Raftari, Maryam; Tollabimazraehno, Sajjad; Mahdavi, Mohammad; Irajizad, Azam

    2012-02-01

    Silver nanoparticles/polystyrene nanocomposites were prepared via casting the solution of polystyrene in a mixture of carbon tetrachloride and acetone containing silver nanoparticles. Colloidal silver nanoparticles in acetone were synthesized by pulsed laser ablation (PLA) of pure bulk silver. Casting the colloidal silver nanoparticles in a solution of polystyrene results in a yellowish transparent polymeric sheet. TEM images show rather spherical nanoparticles with mean diameter of 5 nm. Ag/PS nanocomposites were characterized by UV-VIS spectroscopy. In this study, we also investigated the antimicrobial activity of silver nanocomposites against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) as a model for Gram negative and Gram positive bacteria. Antibacterial tests were performed against E. coli and S.aureus, on LB agar plates containing different amount of nanoparticles. Our results showed at all these concentrations, the nanoparticles caused a growth delay of E. coli, increasing the concentration of nanoparticles increased this growth delay.

  4. Stress relaxation following uniaxial extension of polystyrene melt and oligomer dilutions

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik K.

    2016-01-01

    The filament stretching rheometer has been used to measure the stress relaxation following the startup of uniaxial extensional flow, on anarrow molar mass distribution (NMMD) polystyrene melt and styrene oligomer dilutions thereof. All samples used here were characterizedin molecular weight......, mechanical spectroscopy, and constant strain rate uniaxial extension in the work of Huang et al. [Macromolecules 46,5026–5035 (2013); ACS Macro Lett. 2, 741–744 (2013)]. The stress relaxation following the steady extensional stress was measured on a285 kg/mole NMMD polystyrene and two 1.92 kg/mole styrene...... oligomer dilutions thereof {PS-285k, PS-285k/2k-72, and PS-285k/2k-44 inthe work of Huang et al. [Macromolecules 46, 5026–5035 (2013)]}. The two dilutions contained 28 and 56 wt. % oligomer, respectively.Further, the stress relaxation on a 545 kg/mole NMMD polystyrene diluted with 48 wt. % 0.972 kg...

  5. Relative merits of polystyrene foam and paper in hot drink cups: Implications for packaging

    Science.gov (United States)

    Hocking, Martin B.

    1991-11-01

    An analysis of the overall relative merits of the use of uncoated paper vs molded polystyrene bead foam in single-use 8-oz cups is described here as a manageable example of the use of paper vs plastics in packaging. In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup. Virtually all primary use factors favor polystyrene foam over paper. Once used both cup types may be recycled. Landfill disposal of the two items under dry conditions will occupy similar landfill volumes after compaction and will confer similarly slow to nonexistent decomposition to either option. Under wet conditions polystyrene foam will not readily degrade, but may help other materials to do so. Paper under wet conditions will biodegrade to produce methane, a significant greenhouse gas, biochemical oxygen demand to any leachate, and instability to the land surface during the process. Both materials can be incinerated cleanly in a municipal waste stream with the option of energy recovery, to yield an ash volume of 2% 5% of the incoming waste volume. Overall this analysis would suggest that polystyrene foam, with an extension to plastics in general, should be given more evenhanded consideration relative to paper in packaging applications than is currently the case.

  6. Radiation preparation of nano-powdered styrene-butadiene rubber (SBR) and its toughening effect for polystyrene and high-impact polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Li Daishuang; Xia Haibing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peng Jing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)], E-mail: jpeng@pku.edu.cn; Zhai Maolin; Wei Genshuan; Li Jiuqiang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Qiao Jinliang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); SINOPEC, Beijing Research Institute of Chemical Industry, Beijing 100013 (China)

    2007-11-15

    Nano-powdered styrene-butadiene rubber (NPSBR) was synthesized based on the styrene-butadiene rubber (SBR) latex via gamma radiation crosslinking followed by spray drying. Two functional monomers, 2-ethyl hexyl acrylate (2-EHA) and trimethylolpropane triacrylate (TMPTA) were used as crosslinking agents. It was found that both 2-EHA and TMPTA can improve the radiation crosslinking of SBR latex. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed that the NPSBR has a particle size similar to that of SBR latex with a diameter of 100 nm due to the high degree of crosslinking of SBR. Mechanical testing results showed that NPSBR could toughen polystyrene (PS) and high-impact polystyrene (HIPS) effectively. In addition, NPSBR is more suitable to toughen HIPS than PS at low rubber content.

  7. Diblock copolymers of polystyrene-b-poly(1,3-cyclohexadiene) exhibiting unique three-phase microdomain morphologies

    KAUST Repository

    Misichronis, Konstantinos

    2016-03-31

    The synthesis and molecular characterization of a series of conformationally asymmetric polystyrene-block-poly(1,3-cyclohexadiene) (PS-b-PCHD) diblock copolymers (PCHD: ∼90% 1,4 and ∼10% 1,2), by sequential anionic copolymerization high vacuum techniques, is reported. A wide range of volume fractions (0.27≤ϕPS≤0.91) was studied by transmission electron microscopy and small-angle X-ray scattering in order to explore in detail the microphase separation behavior of these flexible/semiflexible diblock copolymers. Unusual morphologies, consisting of PCHD core(PCHD-1,4)-shell(PCHD-1,2) cylinders in PS matrix and three-phase (PS, PCHD-1,4, PCHD-1,2) four-layer lamellae, were observed suggesting that the chain stiffness of the PCHD block and the strong dependence of the interaction parameter χ on the PCHD microstructures are important factors for the formation of this unusual microphase separation behavior in PS-b-PCHD diblock copolymers. © 2016 Wiley Periodicals, Inc.

  8. Acyclic monoterpenes in tree essential oils as a shrinking agent for waste-expanded polystyrene.

    Science.gov (United States)

    Shimotori, Yasutaka; Hattori, Kazuyuki; Aoyama, Masakazu; Miyakoshi, Tetsuo

    2011-01-01

    We examined the dissolution of polystyrene (PS) into acyclic monoterpenes present in tree essential oils, to develop an environmentally friendly shrinking agent for waste-expanded polystyrene (EPS). The dissolving powers of geranyl acetate, geranylacetone, and geranyl formate [221.8-241.2 g PS (100 g solvent)(-1)] compared favorably with that of (R)-limonene [181.7 g PS (100 g solvent)(-1)]. Their favorable dissolving powers for PS can be explained by their flexible linear structures, which may be more accessible to the inside of bulk PS compared with cyclic monoterpenes. These acyclic monoterpenes and PS were recovered almost quantitatively by simple steam distillation of the PS solution.

  9. A study of the electronic conductance in converting a polyacetylene into polystyrene oligomer

    Directory of Open Access Journals (Sweden)

    H Rabani

    2014-11-01

    Full Text Available In this paper, the electronic conductance of a polyacetylene polymer embedded between two simple chains is studied by using transfer matrix method within the tight-binding and first neighbor approach. Also, by adding benzene molecules to polyacetylene we obtain the system conductance in its conversion to polystyrene polymer. The results show that as the number of benzene molecules in the middle of center system increases the conductance in the tunneling area of polyacetylene improves and this area comes close to the resonance area. In contrast, a part of resonance area tends to transform into polystyrene tunneling zone.

  10. Linear polystyrene-stabilized PdO nanoparticle-catalyzed Mizoroki-Heck reactions in water.

    Science.gov (United States)

    Ohtaka, Atsushi; Yamaguchi, Tomohiro; Teratani, Takuto; Shimomura, Osamu; Nomura, Ryôki

    2011-10-27

    Linear polystyrene-stabilized PdO nanoparticles (PS-PdONPs) were prepared by thermal decomposition of Pd(OAc)(2) in the presence of polystyrene. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated the production of PdO nanoparticles. The loading of palladium was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). PS-PdONPs exhibited high catalytic activity for Mizoroki-Heck reactions under air in water and could be recycled without loss of activity.

  11. Linear Polystyrene-Stabilized PdO Nanoparticle-Catalyzed Mizoroki-Heck Reactions in Water

    Directory of Open Access Journals (Sweden)

    Takuto Teratani

    2011-10-01

    Full Text Available Linear polystyrene-stabilized PdO nanoparticles (PS-PdONPs were prepared by thermal decomposition of Pd(OAc2 in the presence of polystyrene. X-ray diffraction (XRD and transmission electron microscopy (TEM indicated the production of PdO nanoparticles. The loading of palladium was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES. PS-PdONPs exhibited high catalytic activity for Mizoroki-Heck reactions under air in water and could be recycled without loss of activity.

  12. A constitutive analysis of transient and steady-state elongational viscosities of bidisperse polystyrene blends

    DEFF Research Database (Denmark)

    Wagner, Manfred H.; Rolon-Garrido, Victor H.; Nielsen, Jens Kromann

    2008-01-01

    The transient and steady-state elongational viscosity data of three bidisperse polystyrene blends were investigated recently by Nielsen et al. [J. Rheol. 50, 453-476 (2006)]. The blends contain a monodisperse high molar mass component (M-L= 390 kg/ mol) in a matrix of a monodisperse small molar......, and allowing (albeit by use of empirical linear-viscoelastic shift factors to correct the linear-viscoelastic predictions) for a quantitative description of the transient and steady-state elongational viscosities of the bidisperse polystyrene blends....

  13. Increased adsorption of histidine-tagged proteins onto tissue culture polystyrene

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hansen, Thomas Steen; Lind, Johan Ulrik

    2012-01-01

    In this study we compare histidine-tagged and native proteins with regards to adsorption properties. We observe significantly increased adsorption of proteins with an incorporated polyhistidine amino acid motif (HIS-tag) onto tissue culture polystyrene (TCPS) compared to similar proteins without...... a HIS-tag. The effect is not observed on polystyrene (PS). Adsorption experiments have been performed at physiological pH (7.4) and the effect was only observed for the investigated proteins that have pI values below or around 7.4. Competitive adsorption experiments with imidazole...

  14. Influence of growth media and temperature on bacterial adhesion to polystyrene surfaces

    Directory of Open Access Journals (Sweden)

    Ana Eliza Zeraik

    2012-08-01

    Full Text Available Bacterial adhesion to inert surfaces is a complex process influenced by environmental conditions. In this work, the influence of growth medium and temperature on the adhesion of Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, Micrococcus luteus and Listeria monocytogenes to polystyrene surfaces was studied. Most bacteria demonstrated the highest adhesion when cultured in TSYEA, except S. marcescens, which showed to be positively influenced by the pigment production, favored in poor nutrient media (lactose and peptone agar. P. aeruginosa adhesion to polystyrene increased at low temperatures whatever the medium used. The culture medium influenced the surface properties of the bacteria as assessed by the MATS test.

  15. Electrochemical Deposition of Zinc Oxide on the Surface of Composite Membrane Polysulfone-Graphene-Polystyrene in the Presence of Water Soluble Polymers

    Directory of Open Access Journals (Sweden)

    Alexandra Mocanu

    2017-01-01

    Full Text Available The aim of this study consisted in the development of an alternative synthesis procedure for hybrid ultrafiltration membranes for water purification. The membranes were obtained by wet-phase inversion method based on aliquots of polysulfone (PSF and graphene nanoplatelets modified with poly(styrene (G-PST. The hybrid materials were modified by electrochemical deposition of zinc oxide (ZnO on one side of the membranes in the presence of water soluble polymers. Raman, XPS, and TGA analyses were used to characterize the chemical and thermal characteristics of the PST-G. SEM analysis showed the formation of asymmetric porous configuration in all cases and the generation of ZnO with different shapes/structures on the bottom surface of the membrane or inside the porous channels. EDS analysis confirmed the formation of ZnO.

  16. Preparation of Protein Nanoparticles Using NTA End Functionalized Polystyrenes on the Interface of a Multi-Laminated Flow Formed in a Microchannel

    Directory of Open Access Journals (Sweden)

    Hyeong Jin Jeon

    2017-01-01

    Full Text Available This paper challenges the production of the protein nanoparticles using the conjugation of Ni2+ complexed nitrilotriacetic acid end-functionalized polystyrene (Ni-NTA-PS and histidine tagged GFP (His-GFP hybrid. The microfluidic synthesis of the protein nanoparticle with the advantages of a uniform size, a fast reaction, and a precise control of preparation conditions is examined. The self-assembly occurs on the interfacial surface of the multi-laminated laminar flow stably formed in the microchannel. The clogging of the produced protein nanoparticles on the channel surface is solved by adding a retarding inlet channel. The size and shape of the produced protein nanoparticles are measured by the analysis of transmission electron microscopy (TEM and scanning electron microscope (SEM images, and the attachment of the protein is visualized with a green fluorescent image. Future research includes the encapsulation of vaccines and the coating of antigens on the protein surface.

  17. Nanofiltration membranes of poly(styrene- co-chloro-methylstyrene)- grafted-DGEBA reinforced with gold and polystyrene nanoparticles for water purification

    Science.gov (United States)

    Kausar, Ayesha; Siddiq, Muhammad

    2017-06-01

    The matrix material for nanofiltration membranes was prepared through chemical grafting of poly(styrene- co-chloromethylstyrene) (PSCMS) to DGEBA using hexamethylenediamine as linker. The phase inversion technique was used to form PSCMS- g-DGEBA membranes. This effort also involves the designing of gold nanoparticles and its composite nanoparticles with polystyrene microspheres as matrix reinforcement. The nanoporous morphology was observed at lower filler content and there was formation of nanopattern at increased nanofiller content. The tensile strength was improved from 32.5 to 35.2 MPa with the increase in AuNPs-PSNPs loading from 0.1 to 1 wt%. The glass transition temperature was also enhanced from 132 to 159 °C. The membrane properties were measured via nanofiltration set-up. Higher pure water permeation flux, recovery, and salt rejection were measured for novel membranes. PSCMS- g-DGEBA/AuNPs-PSNPs membrane with 1 wt% loading showed flux of 2.01 mL cm-2 min-1 and salt rejection ratio of 70.4 %. Efficiency of the gold/polystyrene nanoparticles reinforced membranes for the removal of Hg2+ and Pb2 was found to be 99 %. Novel hybrid membranes possess fine characteristics to be utilized in industrial water treatment units.

  18. Peptide Synthesis Method and Solid Support for Use in the Method

    DEFF Research Database (Denmark)

    1994-01-01

    or proteins in a parallel and substantially simultaneous fashion. Preferred embodiments of a solid support for performing the synthesis are prepared from thin polyethylene sheet or film which has been grafted with polystyrene chains in a radical-initiated process in which the polyethylene sheet or film...

  19. Application of reactive siloxane prepolymers for the synthesis of thermoplastic poly(ester–siloxanes and poly(ester–ether–siloxanes

    Directory of Open Access Journals (Sweden)

    VESNA V. ANTIC

    2007-02-01

    Full Text Available Thermoplastic poly(ester–siloxanes (TPES and poly(ester–ether–siloxane s, (TPEES, based on poly(butylene terephthalate (PBT as the hard segment and different siloxane-prepolymers as the soft segments, were prepared. The TPES and TPEES were synthesized by catalyzed two-step transesterification from dimethyl terephthalate, (DMT, 1,4-butanediol, (BD and a siloxane-prepolymer. Incorporation of dicarboxypropyl- or disilanol-terminated poly(dimethylsiloxanes (PDMS into the polar poly(butylene terephthalate chains resulted in rather inhomogeneous TPES copolymers, which was a consequence of a prononuced phase separation of the polar and non-polar reactants during synthesis. Two concepts were employed to avoid or reduce phase separation: 1 the use of siloxane-containing triblock prepolymers with hydrophilic terminal blocks, such as ethylene oxide (EO, poly(propylene oxide (PPO or poly(caprolactone (PLC when the terminal blocks serve as a compatibilizer between the extremely non-polar PDMS and the polar DMT and BD, and 2 the use of a high-boiling solvent (1,2,4-trichlorobenzene during the first phase of the reaction. Homogeneity was significantly improved in the case of copolymers based on PCL–PDMS–PCL.

  20. Evaluation of the contact angle and frost resistance of hydrophobised heat-insulating mortars with polystyrene

    Science.gov (United States)

    Barnat-Hunek, Danuta; Łagód, Grzegorz; Klimek, Beata

    2017-07-01

    The aim of the research presented in the paper was to evaluate the feasibility of using hydrophobic preparation based on organosilicon compounds for surface protection on the heat-insulating mortars modified with polystyrene. The work discusses issues related to wettability, absorptivity and frost resistance of the surface layer of mortars. The experimental part pertains to the physical and mechanical properties of polystyrene-modified mortars and the influence of hydrophobic preparation on the contact angle and frost resistance. The frost resistance of mortars was examined following 25 cycles of freezing and thawing. The contact angle of light mortars (θw) was determined before and after the tests of frost resistance, in the function of time using a single measurement liquid. This provided a basis for calculating the surface free energy with Neumann method, characterizing the wettability and adhesion of mortars under normal conditions and with damages resulting from frost weathering. The structure of mortars and the adhesion of lightweight aggregate to cement paste were presented by means of scanning electron microscopy. The studies enabled to determine the hydrophobisation efficiency of heat-insulating mortars with polystyrene. The obtained results confirmed the possibility of producing heat-insulating mortars modified with polystyrene along with proper surface protection against moisture and frost.

  1. Morphology and properties of wood-fiber reinforced blends of recycled polystyrene and polyethylene

    Science.gov (United States)

    John Simonsen; Timothy G. Rials

    1996-01-01

    Material properties of composites produced from recycled plastics and recycled wood fiber were compared. A blend of high-density polyethylene and polystyrene was used as a simulated mixed plastic. Stiffness was generally improved by the addition of fiber, as expected, but brittleness also increased. Pre-treatment of the wood filler with phenol-formaldehyde resins did...

  2. A fresh study of optical and thermal properties of polystyrene solutions

    Indian Academy of Sciences (India)

    Unknown

    have diverted their attention to the Debye temperature, relative association and optical property of polystyrene solutions. The three solvents considered are carbontetra- chloride, benzene and carbondisulphide. 2. Theory. Three aspects have been given special attention. (i) Relative association (RA) and heat of mixing: ...

  3. The determination of chlorofluorocarbons and extractives in the expanded and disposable polystyrene ware.

    Science.gov (United States)

    Sam, C T; Chua, T H

    1991-10-01

    Residual chlorofluorocarbons (CFCs) and water-extractive residues in expanded polystyrene ware were determined because of the threat to environmental and public health arising from the ozone depleting potential of CFCs and the leaching of toxic monomers and oligomers into food and drink. Chlorofluorocarbon in expanded polystyrene ware was analysed using headspace gas chromatography in the flame ionization mode, and confirmed by gas chromatography-mass spectrometry. The amount of extractive residue leached from this type of polymeric material was determined using an aqueous medium simulating categories of food and beverages. A wide range of concentrations of CFC-12 (dichlorodifluorocarbon) was detected in the styrofoam ware. It fluctuated between a low of 32 ppm and a high of 35471 ppm in two different samples of styrofoam plates. Similarly, the highest and lowest levels of extractive residue detected in two different styrofoam plates were 54 ppm and 0.5 ppm respectively. CFC-22 or HCFC (chlorodifluorocarbon) was absent from these expanded polystyrene ware. The continued use of chlorofluorocarbons as a blowing agent will further exert a deleterious effect on the stratospheric ozone layer. Though the level of water extractive residue from these expanded polystyrene ware was relatively safe, public health could be further safe-guarded through improvmeents in raw material selection and mode of production.

  4. Designing strip footing foundations using expanded polystyrene (EPS) as fill material

    DEFF Research Database (Denmark)

    Psarropoulos, Prodromos; Zania, Varvara; Spyrakos, Konstantinos

    2010-01-01

    One of the modern uses of expanded polystyrene (EPS) is in strip footings as fill material. The current study investigates the effect of the geofoam filling in the static and seismic design of the base slab founded on strip footings. For this purpose the finite element method is employed, and three...

  5. Polystyrene film-coated glassware : a new means of reducing metal losses in trace metal speciation

    NARCIS (Netherlands)

    Pinheiro, J.P.; Bosker, W.T.E.

    2004-01-01

    A recently developed process for coating a glass surface with polystyrene (PS) film, by use of a simple chemical process has been used to reduce trace metal adsorption by cell components. The glass coating is a two-step procedure consisting of covalent attachment of vinyl-terminated PS to Si atoms

  6. EGDMA–cross-linked polystyrene resin: An efficient support for gel ...

    Indian Academy of Sciences (India)

    Unknown

    acetone followed by methanol to remove linear polymers and low molecular weight products. The beads were meshed to 200–400 range. Yield of the polymer obtained was. 85%. For preparation of the divinylbenzene–cross-linked polystyrene (DVB–PS), the same procedure was employed and the yield polymer obtained ...

  7. Nano-sized polystyrene affects feeding, behavior and physiology of brine shrimp Artemia franciscana larvae

    NARCIS (Netherlands)

    Bergami, Elisa; Bocci, Elena; Vannuccini, Maria Luisa; Monopoli, Marco; Salvati, Anna; Dawson, Kenneth A; Corsi, Ilaria

    Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on

  8. MOF-5-Polystyrene: Direct Production from Monomer, Improved Hydrolytic Stability, and Unique Guest Adsorption.

    Science.gov (United States)

    Gamage, Nipuni-Dhanesha H; McDonald, Kyle A; Matzger, Adam J

    2016-09-19

    An unprecedented mode of reactivity of Zn4 O-based metal-organic frameworks (MOFs) offers a straightforward and powerful approach to polymer-hybridized porous solids. The concept is illustrated with the production of MOF-5-polystyrene wherein polystyrene is grafted and uniformly distributed throughout MOF-5 crystals after heating in pure styrene for 4-24 h. The surface area and polystyrene content of the material can be fine-tuned by controlling the duration of heating styrene in the presence of MOF-5. Polystyrene grafting significantly alters the physical and chemical properties of pristine MOF-5, which is evident from the unique guest adsorption properties (solvatochromic dye uptake and improved CO2 capacity) as well as the dramatically improved hydrolytic stability of composite. Based on the fact that MOF-5 is the best studied member of the structure class, and has been produced at scale by industry, these findings can be directly leveraged for a range of current applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. High-yield preparation of polystyrene/silica clusters of controlled morphology

    OpenAIRE

    Désert, Anthony; Chaduc, Isabelle; Fouilloux, Sarah; Taveau, Jean-Christophe; Lambert, Olivier; Lansalot, Muriel; Bourgeat-Lami, Elodie; Thill, Antoine; Spalla, Olivier; Ravaine, Serge; Duguet, Etienne

    2012-01-01

    3 pages; International audience; Large amounts of regular tetrapods and hexapods made of a central silica core and four or six polystyrene satellite nodules were prepared with yields over 80% from 55 nm and 85 nm silica seeds, respectively. The robustness of the process is supported by extensive statistical analyses and large-field transmission electron microscopy images.

  10. Polystyrene-b-polyethylene oxide block copolymer membranes, methods of making, and methods of use

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-04-16

    Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

  11. Influence of diblock copolymer on the morphology and properties of polystyrene/poly(dimethylsiloxane) blends

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Li, Shu; Almdal, Kristoffer

    2004-01-01

    Blends of polystyrene (PS) and poly(dimethylsiloxane) (PDMS), with and without diblock copolymers (PS-b-PDMS), were prepared by melt mixing. The melt rheology behavior of the blends was studied with a capillary rheometer. The morphology of the blends was examined with scanning electron microscopy...

  12. submitter Preparation and luminescence properties of ZnO:Ga – polystyrene composite scintillator

    CERN Document Server

    Burešová, Hana; Turtos, Rosana Martinez; Jarý, Vítězslav; Mihóková, Eva; Beitlerová, Alena; Pjatkan, Radek; Gundacker, Stefan; Auffray, Etiennette; Lecoq, Paul; Nikl, Martin; Čuba, Václav

    2016-01-01

    Highly luminescent ZnO:Ga-polystyrene composite (ZnO:Ga-PS) with ultrafast subnanosecond decay was prepared by homogeneous embedding the ZnO:Ga scintillating powder into the scintillating organic matrix. The powder was prepared by photo-induced precipitation with subsequent calcination in air and Ar/H2 atmospheres. The composite was subsequently prepared by mixing the ZnO:Ga powder into the polystyrene (10 wt% fraction of ZnO:Ga) and press compacted to the 1 mm thick pellet. Luminescent spectral and kinetic characteristics of ZnO:Ga were preserved. Radioluminescence spectra corresponded purely to the ZnO:Ga scintillating phase and emission of polystyrene at 300-350 nm was absent. These features suggest the presence of non-radiative energy transfer from polystyrene host towards the ZnO:Ga scintillating phase which is confirmed by the measurement of X-ray excited scintillation decay with picosecond time resolution. It shows an ultrafast rise time below the time resolution of the experiment (18 ps) and a single-...

  13. Surfactant-induced thermomechanical and morphological changes in TiO2-polystyrene nanocomposites.

    Science.gov (United States)

    Patra, Niranjan; Salerno, Marco; Cozzoli, Pantaleo D; Athanassiou, Athanassia

    2013-09-01

    Nanocomposites of polystyrene and TiO2 colloidal nanorods with different loadings have been prepared by mixing pre-synthesized oleic acid capped colloidal TiO2 nanorods into commercial polystyrene via solvent blending using chloroform. The microstructure and morphology of the nanocomposites was evaluated by wide angle X-ray diffraction and transmission electron microscopy. The observations revealed that the surfactant plays an important role for interactions between the polymer and the filler. Differential scanning calorimetry showed that the glass transition temperature of the nanocomposites decreased which is consistent with the surfactant acting as a plasticizer in the polystyrene matrix. Thermogravimetric analysis revealed that the nanocomposites show no significant improvement in thermal stability as compared to the bare PS up to a temperature of 400 °C. However, after 400 °C, the TGA curve shifts a little to higher temperature as compared to the bare PS. The dynamic mechanical properties of the nanocomposites indicate that the storage modulus, loss modulus, and glass transition temperature do not change with increasing nanorods content of 2 and 4 wt% but decrease afterward for 8 wt%. Transmission electron microscopy images clearly show debonding characteristics in polystyrene matrix. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Rapid coagulation of polystyrene latex in a stopped-flow spectrophotometer

    NARCIS (Netherlands)

    Lichtenbelt, J.W.Th.; Pathmamanoharan, C.; Wiersema, P.H.

    1974-01-01

    With a stopped-flow method the rapid coagulation by electrolyte of several polystyrene latices is measured. By extrapolating back to zero time the initial process of two single particles forming a doublet is observed. We find an average rate constant ifk11 = 6.0 × 10−12 p−1 cm3 sec su−1 at 20°C,

  15. Electrokinetic properties and conductance relaxation of polystyrene and silver iodide plugs

    NARCIS (Netherlands)

    Hoven, van den J.J.

    1984-01-01

    This thesis describes an experimental study on the electrokinetic and electrical properties of concentrated polystyrene and silver iodide dispersions. The purpose of the study is to obtain information on the structure of the electrical double layer at the solid-liquid interface. Special

  16. Extensional Rheology of Entangled Polystyrene Solutions Suggests Importance of Nematic Interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi

    2013-01-01

    We compare the linear and nonlinear rheological response of three entangled polystyrene solutions with the same concentration of polymer, but diluted using different solvents. The three solutions have exactly the same physical tube model parameters when normalized to the same time scale. Although...

  17. Shear and Extensional Rheology of Polystyrene Melts and Solutions with the Same Number of Entanglements

    DEFF Research Database (Denmark)

    Costanzo, Salvatore; Huang, Qian; Ianniruberto, Giovanni

    2016-01-01

    We investigate the nonlinear shear and uniaxial extensional rheology of entangled polystyrene (PS) melts and solutions having the same number Z of entanglements, hence identical linear viscoelasticity. While experiments in extensional flows confirm that PS melts and solutions with the same Z behave...

  18. Studying the Adhesion Force and Glass Transition of Thin Polystyrene Films by Atomic Force Microscopy

    DEFF Research Database (Denmark)

    Kang, Hua; Qian, Xiaoqin; Guan, Li

    2018-01-01

    microscopy (AFM)-based forcedistance curve to study the relaxation dynamics and the film thickness dependence of glass transition temperature (T-g) for normal thin polystyrene (PS) films supported on silicon substrate. The adhesion force (F-ad) between AFM tip and normal thin PS film surfaces...

  19. Impact of non-ionic surfactant chemical structure on morphology and stability of polystyrene nanocomposite latex

    CSIR Research Space (South Africa)

    Greesh, N

    2016-01-01

    Full Text Available Polystyrene (PS) colloid particles in presence of non-ionic surfactant-modified clay particles were prepared by the free-radical polymerization of styrene monomers in emulsion. Three different types of non-ionic surfactants, sorbitan monopalmitate...

  20. Rheological Behavior of Entangled Polystyrene-Polyhedral Oligosilsesquioxane (POSS) Copolymer (Postprint)

    National Research Council Canada - National Science Library

    Wu, Jian; Mather, Patrick T; Haddad, Timothy S; Kim, Gyeong-Man

    2006-01-01

    ...: random copolymers of polystyrene (PS) and styryl-based polyhedral oligosilsesquioxane (POSS), R7(Si8O12)(C6H4CH=CH2), with R = isobutyl (iBu). A series of styrene-styryl POSS random copolymers with 0, 6, 15, 30, 50 wt...

  1. Stress relaxation of entangled polystyrene solution after constant-rate, uniaxial elongation

    DEFF Research Database (Denmark)

    Matsumiya, Yumi; Masubuchi, Yuichi; Watanabe, Hiroshi

    For an entangled solution of linear polystyrene (PS 545k; M = 545k) in dibutyl phthalate (DBP), the stress relaxation after constant-rate uniaxial elongation was examined with an extensional viscosity fixture mounted on ARES (TA Instruments). The PS concentration, c = 52 wt%, was chosen in a way...

  2. Coarse-graining polymers with the MARTINI force-field: polystyrene as a benchmark case

    DEFF Research Database (Denmark)

    Rossi, G.; Monticelli, L.; Puisto, S. R.

    2011-01-01

    in the parameterization. We refine the MARTINI procedure by including one additional target property related to the structure of the polymer, namely the radius of gyration. The force-field optimization is mainly based on experimental data. We test our procedure on polystyrene, a standard benchmark for coarse-grained (CG...

  3. Predicting the Solubility of 1,1-Difluoroethane in Polystyrene Using the Perturbed Soft Chain Theory

    DEFF Research Database (Denmark)

    Pretel, Eduardo; Hong, Seong-Uk

    1998-01-01

    In this study, the solubility of 1,1-difluoroethane in polystyrene was correlated and predicted using the Perturbed Soft Chain Theory (PSCT) and compared with experimental data from the literature. For correlation, a binary interaction parameter was determined by using experimental solubility data...

  4. Stress relaxation of narrow molar mass distribution polystyrene following uniaxial extension

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.; Hassager, Ole

    2008-01-01

    The stress in the startup of uniaxial elongational flow until steady state, followed by stress relaxation, has been measured for a narrow molar mass distribution polystyrene inelt with a molecular weight of 145 kg/mol. The experiments are conducted on a filament stretching rheometer, where a closed...

  5. Extensional rheology of entangled polystyrene solutions suggests importance of nematic interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi

    polymer solutions in extensional flow. We prepared three polystyrene (PS) solutions with identical concentrations of the same PS sample (with the molecular weight M = 545k), but diluted with three different solvents, oligomeric styrene (OS) with M = 1k, 2k, and 4k. The three solutions have exactly...

  6. Melt compounding of different grades of polystyrene with organoclay. Part 2: Rheological properties

    DEFF Research Database (Denmark)

    Tanoue, Shuichi; Utracki, Leszek A.; Garcia-Rejon, Andrés

    2004-01-01

    Polystrene-based nanocomposites (PNC) were prepared using three grades of polystyrene (different molecular weights). The resin was melt-compounded with 0 to 10 wt% of commercial organoclay in a co-rotating twin-screw extruder. Owing to thermo-oxidative degradation the degree of dispersion was poor...

  7. Autoadhesion of High-Molecular-Weight Monodisperse Glassy Polystyrene at unexpected low temperatures

    DEFF Research Database (Denmark)

    Boiko, Yuri M.; Lyngaae-Jørgensen, Jørgen

    2004-01-01

    Healing of symmetric interfaces of amorphous anionically polymerized high- and ultra-high-molecular weight (HMW and UHMW, respectively) polystyrene (PS) in a range of the weight-average molecular weight M-w from 102.5 (M-w/M-n = 1.05) to 1110 kg/ mol (M-w/M-n = 1.15) was followed at a constant...

  8. Comparison of ionisation measurements in water and polystyrene for electron beam dosimetry.

    Science.gov (United States)

    Bruinvis, I A; Heukelom, S; Mijnheer, B J

    1985-10-01

    For the determination of absorbed dose to water in electron beams, dosimetry protocols advocate ionisation measurements in plastic phantoms instead of water for practical reasons. The chamber readings in polystyrene at the depth of maximum ionisation must be corrected for the difference in physical properties between the two materials. This correction factor was determined for a Farmer 0.6 cm3 graphite-walled chamber in electron beams with mean energies at the phantom surface between 6 and 19 MeV. Experiments with white polystyrene yielded corrections for the measured ionisation ranging from 0.3 to 2.4%. For clear polystyrene, 0.6-1% higher corrections were found. For beams with the same mean energy at the phantom surface, but with different beam-flattening and collimation systems, variations in this correction up to 1.2% were observed. In contrast to recent reports on electrical charge storage in polystyrene due to electron irradiation, our experiments do not show differences in the chamber readings any larger than 0.5%.

  9. Influence of low contents of superhydrophilic MWCNT on the properties and cell viability of electrospun poly (butylene adipate-co-terephthalate) fibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruno V.M.; Silva, Aline S. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Melo, Gabriela F.S.; Vasconscellos, Luana M.R. [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, Sao Paulo State University (UNESP), Av. Engenheiro Francisco Jose Longo 777, Sao Jose dos Campos, Sao Paulo (Brazil); Marciano, Fernanda R. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Lobo, Anderson O., E-mail: aolobo@pq.cnpq.br [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil)

    2016-02-01

    The use of poly (butylene adipate-co-terephthalate) (PBAT) in tissue engineering, more specifically in bone regeneration, has been underexplored to date due to its poor mechanical resistance. In order to overcome this drawback, this investigation presents an approach into the preparation of electrospun nanocomposite fibers from PBAT and low contents of superhydrophilic multi-walled carbon nanotubes (sMWCNT) (0.1–0.5 wt.%) as reinforcing agent. We employed a wide range of characterization techniques to evaluate the properties of the resulting electrospun nanocomposites, including Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM), tensile tests, contact angle measurements (CA) and biological assays. FE-SEM micrographs showed that while the addition of sMWCNT increased the presence of beads on the electrospun fibers' surfaces, the increase of the neat charge density due to their presence reduced the fibers' average diameter. The tensile test results pointed that sMWCNT acted as reinforcement in the PBAT electrospun matrix, enhancing its tensile strength (from 1.3 to 3.6 MPa with addition of 0.5 wt.% of sMWCNT) and leading to stiffer materials (lower elongation at break). An evaluation using MG63 cells revealed cell attachment into the biomaterials and that all samples were viable for biomedical applications, once no cytotoxic effect was observed. MG-63 cells osteogenic differentiation, measured by ALP activity, showed that mineralized nodules formation was increased in PBAT/0.5%CNTs when compared to control group (cells). This investigation demonstrated a feasible novel approach for producing electrospun nanocomposites from PBAT and sMWCNT with enhanced mechanical properties and adequate cell viability levels, which allows for a wide range of biomedical applications for these materials. - Highlights: • Nanocomposites from PBAT and superhydrophilic MWCNT (sMWCNT) were successfully prepared by electrospinning

  10. Syntheses, spectroscopic and magnetic properties of polystyrene-anchored coordination compounds of thiazolidinone

    Directory of Open Access Journals (Sweden)

    D. Kumar

    2014-01-01

    Full Text Available The reaction between polystyrene 3-formylsalicylate and furoic acid hydrazide in DMF in the presence of ethyl acetate results in the formation of polystyrene N-(2-carbamoylfuranyl-3'-carboxy-2'-hydroxybenzylideneimine (I. A benzene suspension of I reacts with mercaptoacetic acid and forms the polystyrene N-(2-carbamoylfuranyl-C-(3'-carboxy-2'-hydroxyphenylthiazolidin-4-one, PSCH2–LH2 (II. A DMF suspension of II reacts with Mn(II, Ni(II, Cd(II, Fe(III and UO2(VI ions and forms the polystyrene-anchored coordination compounds of the types, [PSCH2–LMn(DMF3], [PSCH2–LNi(DMF3], [PSCH2–LCd(DMF], [PSCH2–LH2FeCl3] and [PSCH2–LHUO2(NO3(DMF]. The polystyrene-anchored coordination compounds have been characterized on the basis of elemental analyses, spectral (IR, reflectance studies and magnetic susceptibility measurements. II acts as a neutral tridentate ONO donor ligand in [PSCH2–LH2FeCl3], a monobasic tridentate ONO donor ligand in [PSCH2–LHUO2(NO3(DMF], a dibasic tridentate ONO donor ligand in [PSCH2–LMn(DMF3], [PSCH2–LNi(DMF3] and [PSCH2–LCd(DMF]. A tetrahedral structure for Cd(II and an octahedral structure for Mn(II, Ni(II, Fe(III and a square-antiprism geometry for UO2(VI complex are suggested. DOI: http://dx.doi.org/10.4314/bcse.v28i1.4

  11. Interactions between a polystyrene particle and hydrophilic and hydrophobic surfaces in aqueous solutions.

    Science.gov (United States)

    Thormann, Esben; Simonsen, Adam C; Hansen, Per L; Mouritsen, Ole G

    2008-07-15

    The interaction between a colloidal polystyrene particle mounted on an AFM cantilever and a hydrophilic and a hydrophobic surface in aqueous solution is investigated. Despite the apparent simplicity of these two types of systems a variety of different types of interactions are observed. The system containing the polystyrene particle and a hydrophilic surface shows DLVO-like interactions characteristic of forces between charged surfaces. However, when the surface is hydrophobized the interaction changes dramatically and shows evidence of a bridging air bubble being formed between the particle and the surface. For both sets of systems, plateaus of constant force in the force curves are obtained when the particle is retracted from the surface after being in contact. These events are interpreted as a number of individual polystyrene molecules that are bridging the polystyrene particle and the surface. The plateaus of constant force are expected for pulling a hydrophobic polymer in a bad (hydrophilic) solvent. The plateau heights are found to be of uniform spacing and independent of the type of surface, which suggests a model by which collapsed polymers are extended into the aqueous medium. This model is supported by a full stretching curve showing also the backbone elasticity and a stretching curve obtained in pentanol, where the plateau changes to a nonlinear force response, which is typical for a polymer in a good or neutral solvent. We suggest that these polymer bridges are important in particular for the interaction between polystyrene and the hydrophilic surface, where they to some extent counteract the long-range electrostatic repulsion.

  12. Thermally-induced transformation of hexabromocyclo dodecanes and isobutoxypenta bromocyclododecanes in flame-proofed polystyrene materials.

    Science.gov (United States)

    Heeb, Norbert V; Graf, Heidi; Schweizer, W Bernd; Lienemann, P

    2010-08-01

    Polystyrenes (PS) are produced in quantities exceeding 10 Mt y(-1). They are used for insulation and packaging materials, often in flame-proofed forms with hexabromocyclododecanes (HBCDs) added as flame retardants. Polystyrenes are also constituents of plastic debris found in the aquatic environment. HBCDs are now considered as persistent, bioaccumulative, and toxic compounds. Lately, we reported that isobutoxypenta bromocyclododecanes (iBPBCDs), a formerly unknown class of polybrominated compounds, are also present in flame-proofed polystyrenes. It is therefore likely that iBPBCDs are released along with HBCDs from these materials. Herein, we report on changes of the HBCD- and iBPBCD-patterns when exposing expanded (EPS) and extruded (XPS) polystyrenes at temperatures of 140-160 degrees C. Substantial transformation reactions were observed in EPS, which was rich in gamma-HBCDs and delta-, eta-, and theta-iBPBCDs at the beginning, but changed to materials rich in alpha-HBCDs and alpha-, beta-, epsilon-, and xi-iBPBCDs. Patterns of untreated XPS already resembled those of the thermally treated EPS. Upon thermal exposure, some further enrichment of alpha-HBCDs and alpha-, beta-, epsilon-, and xi-iBPBCDs was also noticed for the XPS samples, indicating similar transformation mechanisms. Comparable apparent first-order transformation rate constants (k(trans)) of -0.003, -0.008, and -0.020 min(-1) and -0.004, -0.009, and -0.019 min(-1) are found for gamma-HBCD- and delta-iBPBCD-conversion at 140, 150, and 160 degrees C, respectively. We conclude that a thermal treatment of flame-proofed polystyrenes alters their HBCD- and iBPBCD-patterns. Thus depending on the proportions of EPS and XPS materials reaching the environment, more of the lipophilic (late-eluting) or of the more polar (early-eluting) HBCD- and iBPBCD-stereoisomers will be released. Several properties such as partitioning coefficients, degradation rates, and bioaccumulation factors are stereoisomer

  13. Leachate From Expanded Polystyrene Cups Is Toxic to Aquatic Invertebrates (Ceriodaphnia dubia

    Directory of Open Access Journals (Sweden)

    Clara Thaysen

    2018-02-01

    Full Text Available Expanded polystyrene (EPS products and their associated chemicals (e.g., styrenes are widespread in the marine environment. As a consequence, bans on their use for single-use packaging materials are being proposed in several municipalities. To better understand how science can inform decision-making, we looked at the available scientific literature about contamination and effects and conducted experiments to measure chemical leachate from polystyrene products and toxicity from the leachate. We conducted leaching experiments with common food matrices (water, soup broth, gravy, black coffee and coffee with cream and sugar at relevant temperatures (70 and 95°C that are consumed in or with several polystyrene products (coffee cup lids, polystyrene stir sticks, polystyrene spoons, EPS cups, EPS bowls, and EPS takeout containers. We analyzed each sample for styrene, ethylbenzene, toluene, benzene, meta- and para- xylene, isopropylbenzene, and isopropyltoluene—chemicals associated with polystyrene products. To determine whether the leachates are toxic, we conducted chronic toxicity tests, measuring survival and reproductive output in Ceriodaphnia dubia. Toxicity tests included nine treatments: seven concentrations of ethylbenzene, EPS cup leachate and a negative control. Overall, we found that temperature has a significant effect on leaching. We only detected leachates in trials conducted at higher temperature −95°C. Ethylbenzene was the only target analyte with final concentrations above the method limit of detection, and was present in the greatest concentrations in EPS and with soup broth. Measurable concentrations of ethylbenzene in the leachate ranged from 1.3 to 3.4 μg/L. In toxicity tests, the calculated LC50 for ethylbenzene was 14 mg/L and the calculated LC20 was 210 μg/L. For the treatment exposed to the EPS cup leachate, mortality was 40%—four times greater than the negative control. Finally, there was no significant difference (p

  14. Preparation of nanocomposites based on poly(Butylene Succinate) and montmorillonite organoclay via in situ polymerization; Preparo de nanocompositos de poli(succinato de butileno) (PDS) e argila motmorilonita organofilica via polimerizaco in situ

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Leticia P.; Moreira, Andrei N.; Souza Junior, Fernando G. de, E-mail: fgsj@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Pinto, Jose Carlos Costa da Silva [Coordenacao dos Cursos de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Quimica

    2014-09-15

    Nanocomposites based on poly(butylene succinate) (PBS) and organophilic montmorillonite were synthesized via in situ polymerization using three different clay compositions (4, 6 and 8 wt%). The products were characterized by several different techniques. X-ray diffraction was useful to confirm the increase of the interlayer spacing of the clay due to the presence of the polymer chains among layers. Thermal analysis indicated that the polymerization method chosen led to materials with lower thermal stability compared to the pure PBS, due to the difficulty of chain growth in the presence of the clay. Low-field NMR technique was used to assess clay dispersion in the polymer, with exfoliated structures predominating in the nanocomposites. (author)

  15. Boring crustaceans damage polystyrene floats under docks polluting marine waters with microplastic.

    Science.gov (United States)

    Davidson, Timothy M

    2012-09-01

    Boring isopods damage expanded polystyrene floats under docks and, in the process, expel copious numbers of microplastic particles. This paper describes the impacts of boring isopods in aquaculture facilities and docks, quantifies and discusses the implications of these microplastics, and tests if an alternate foam type prevents boring. Floats from aquaculture facilities and docks were heavily damaged by thousands of isopods and their burrows. Multiple sites in Asia, Australia, Panama, and the USA exhibited evidence of isopod damage. One isopod creates thousands of microplastic particles when excavating a burrow; colonies can expel millions of particles. Microplastics similar in size to these particles may facilitate the spread of non-native species or be ingested by organisms causing physical or toxicological harm. Extruded polystyrene inhibited boring, suggesting this foam may prevent damage in the field. These results reveal boring isopods cause widespread damage to docks and are a novel source of microplastic pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Optimization of the wavelength shifter ratio in a polystyrene based plastic scintillator through energy spectrum analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ye Won; Kim, Myung Soo; Yoo, Hyun Jun; Lee, Dae Hee; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of); Moon, Myung Kook [Neutron Instrumentation Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-02-15

    The scintillation efficiency of the polystyrene based plastic scintillator depends on the ratio of the wavelength shifters, organic fluors (PPO and POPOP). Thus, 24 samples of the plastic scintillator were fabricated in order to find out the optimum ratio of the wavelength shifters in the plastic scintillator. The fabricated plastic scintillators were trimmed through a cutting and polishing process. They were used in gamma energy spectrum measurement with the {sup 137}Cs emitting monoenergy photon with 662 keV for the comparison of the scintillation efficiency. As a result, it was found out that the scintillator sample with 1.00 g of PPO (2,5-Diphenyloxazole) and 0.50 g of POPOP (1,4-Bis(5-phnyl-2oxidazolyl)benzene) dissolved in 100 g of styrene solution has the optimum ratio in terms of the light yield of the polystyrene based plastic scintillator.

  17. Diffusion of homologous model migrants in rubbery polystyrene: molar mass dependence and activation energy of diffusion.

    Science.gov (United States)

    Pinte, Jérémy; Joly, Catherine; Dole, Patrice; Feigenbaum, Alexandre

    2010-04-01

    Published diffusion prediction models for the diffusion of additives in food packaging simplify reality by having a small number of parameters only. Therefore, extrapolation of such models to barrier polymers, larger ranges of temperature and/or additive molecular weight (M(W)) is questionable. Extra data is still required to generalize these existing prediction models. In this paper, diffusion of a specifically designed homologous set of model additives (from 236 to 1120 g mol(-1)) was monitored in two polystyrenes in the rubbery state (from 100 to 180 degrees C): syndiotactic semi-crystalline polystyrene and its amorphous equivalent. Variations in associated diffusion coefficient D and activation energy Ea with migrant M(W) and temperature were surprisingly low. Comparison of experimental behaviour with model predictions was performed. In their actual form, none of the models is capable of describing all experimental data, but there is evidence of convergence of the different approaches.

  18. A quantitative relationship between Tgs and chain segment structures of polystyrenes

    Directory of Open Access Journals (Sweden)

    Xinliang Yu

    Full Text Available Abstract The glass transition temperature (Tg is a fundamental characteristic of an amorphous polymer. A quantitative structure-property relationship (QSPR based on error back-propagation artificial neural network (ANN was constructed to predict Tgs of 107 polystyrenes. Stepwise multiple linear regression (MLR analysis was adopted to select an optimal subset of molecular descriptors. The chain segments (or motion units of polymer backbones with 20 carbons in length (10 repeating units were used to calculate these molecular descriptors reflecting polymer structures. The relative optimal conditions of ANN were obtained by adjusting various network paramters by trial-and-error. Compared to the model already published in the literature, the optimal ANN model with [4-7-1] network structure in this paper is accurate and acceptable, although our model has more samples in the test set. The results demonstrate the feasibility and powerful ability of the chain segment structures as representative of polymers for developing Tg models of polystyrenes.

  19. Quantitative prediction of transient and steady-state elongational viscosity of nearly monodisperse polystyrene melts

    DEFF Research Database (Denmark)

    Wagner, Manfred H.; Kheirandish, Saeid; Hassager, Ole

    2005-01-01

    starts at elongation rates larger than the inverse reptation time, and the steady-state elongational viscosities decrease with increasing elongation rate according to a power law with a power-law index of approximately - 1 / 2 instead of - 1 as predicted by the original Doi-Edwards tube model. Marrucci...... show that the transient and steady-state elongational viscosities of the nearly monodisperse polystyrene melts can be modeled quantitatively by assuming affine chain deformation balanced by the interchain pressure term of Marrucci and Ianniruberto. The interchain pressure is governed by a tube diameter...... relaxation time tau(a), which is found to be larger than the Rouse time tau(R) of the chain, and which is the only parameter of the model. For monodisperse polystyrene melts of sufficient low molar mass, tau(a), is larger than the reptation time, and a maximum in the steady-state elongational viscosity...

  20. Spin-Coating of Polystyrene Thin Films as an Advanced Undergraduate Experiment

    Science.gov (United States)

    Chakraborty, Mriganka; Chowdhury, Devasish; Chattopadhyay, Arun

    2003-07-01

    A simpler version of the well-established technique of spin-coating thin polymer films on glass slides is described. Starting with simple instrumentation and using an ordinary, commercially available cooling fan (a "CPU cooler"), a method of spin-coating an expanded polystyrene foam on glass slides is described. Making thin films of commercially available polystyrene on glass slides is also included for comparison. An interferometric technique is used to measure the film thickness employing a UV vis spectrophotometer. FTIR spectroscopy is used to verify the identity of the polymer on the glass slide. Using the Beer Lambert law of absorbance, the film thickness is also calculated from the FTIR spectra of films. A comparison is made between the interferometric and FTIR methods for thickness measurements. An organic dye is doped into a film and a UV vis spectrum is used to identify the dye.

  1. The absence of physical-aging effects on the surface relaxations of rubbed polystyrene

    Science.gov (United States)

    Wong, C. C.; Qin, Z.; Yang, Z.

    2008-03-01

    Extensive experimental results are presented to reveal the relaxations of polystyrene surface deformed by rubbing with a velvet cloth. We found that surface topographic features, such as ditches and ridges created by rubbing, relax at temperatures at about 20°C below the bulk glass transition temperature of the polystyrene for a molecular weight of 442 kg/mol, even though we estimate the Laplace Pressure driving the relaxation to be 1/500 of the yield limit. The relaxation is independent of the thermal history before the rubbing process, and post rubbing thermal history below 55°C . In other words, physical-aging processes at 23°C for up to 7 days and at 50°C for 2 days, which would have drastic effects on the relaxations of bulk polymers, have little effects on the relaxations of rubbed surfaces. This is consistent with the mobility enhancement in the surface layer previously reported in the literature.

  2. Microbial production of extra-cellular phytase using polystyrene as inert solid support.

    Science.gov (United States)

    Gautam, Pinky; Sabu, A; Pandey, Ashok; Szakacs, George; Soccol, Carlos R

    2002-07-01

    Aspergillus ficuum TUB F-1165 and Rhizopus oligosporus TUB F-1166 produced extra-cellular phytase during solid-state fermentation (SSF) using polystyrene as inert support. Maximal enzyme production (10.07 U/g dry substrate (U/gds) for A. ficuum and 4.52 U/gds for R. oligosporus) was observed when SSF was carried out with substrate pH 6.0 and moisture 58.3%, incubation temperature 30 degrees C, inoculum size of 1.3 x 10(7) spores/5 g substrate, for 72 h for A. ficuum and with substrate pH 7.0 and moisture 58.3%, incubation temperature 30 degrees C, inoculum size of 1 x 10(6) spores/5 g substrate for 96 h for R. oligosporus. Results indicated scope for production of phytase using polystyrene as inert support.

  3. Altered behavior, physiology, and metabolism in fish exposed to polystyrene nanoparticles.

    Science.gov (United States)

    Mattsson, Karin; Ekvall, Mikael T; Hansson, Lars-Anders; Linse, Sara; Malmendal, Anders; Cedervall, Tommy

    2015-01-06

    The use of nanoparticles in consumer products, for example, cosmetics, sunscreens, and electrical devices, has increased tremendously over the past decade despite insufficient knowledge about their effects on human health and ecosystem function. Moreover, the amount of plastic waste products that enter natural ecosystems, such as oceans and lakes, is increasing, and degradation of the disposed plastics produces smaller particles toward the nano scale. Therefore, it is of utmost importance to gain knowledge about how plastic nanoparticles enter and affect living organisms. Here we have administered 24 and 27 nm polystyrene nanoparticles to fish through an aquatic food chain, from algae through Daphnia, and studied the effects on behavior and metabolism. We found severe effects on feeding and shoaling behavior as well as metabolism of the fish; hence, we conclude that polystyrene nanoparticles have severe effects on both behavior and metabolism in fish and that commonly used nanosized particles may have considerable effects on natural systems and ecosystem services derived from them.

  4. Characterisation of polystyrene coatings after plasma immersion ion implantation and adsorption of protein

    CERN Document Server

    Dekker, S; Steel, B; Bilek, M M M; McKenzie, D R; James, M

    2012-01-01

    A polystyrene film spun onto polished silicon substrates was implanted with either nitrogen or argon ions using plasma immersion ion implantation (PIII) and subsequently investigated by X-ray and neutron reflectometry, UV-VIS and FTIR ellipsometry, as well as by FTIR and Raman spectroscopy. The depth profile of the densified carbon structures resulting from the ion collision cascades in the polystyrene coating are clearly observed by both X-ray and neutron reflectometry. Argon ions produce a higher density modified layer at a shallower depth than nitrogen ions. The thickness measured for these graded layers agrees with the expected depths of ion implantation as calculated by SRIM. The sensitivity of X-ray and neutron reflectometry allows resolution of density and hydrogen content gradients within the graphitized layers. The treated layers were found to covalently immobilized protein directly from solution. The tropoelastin protein monolayers immobilized on the surface were characterized. Tropoelastin remained...

  5. Matrix-assisted laser desorption/ionization-collision induced dissociation of poly(styrene).

    Science.gov (United States)

    Jackson, A T; Yates, H T; Scrivens, J H; Green, M R; Bateman, R H

    1998-04-01

    Matrix-assisted laser desorption/ionization-collision induced dissociation (MALDI-CID) has been employed for the analysis of poly(styrene) in a tandem hybrid sector-time of flight instrument. Spectra are shown for adducts of poly(styrene) with copper and silver ions. The distributions of fragment ion peaks were found to be consistent from precursor ions containing both metal ions. It is shown how the masses of the end groups of the polymer may be inferred from the mass-to-charge ratios of two of the series of ion peaks that are seen in the MALDI-CID spectra. Mechanisms are proposed for the formation of some of the other series of ion peaks that are observed in the spectra.

  6. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    Science.gov (United States)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Hyeok Choi, Byeong; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon; Son, Sang Wook

    2011-07-01

    The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

  7. Design and evaluation of expanded polystyrene geofoam embankments for the I-15 reconstruction project, Salt Lake City, Utah.

    Science.gov (United States)

    2012-10-01

    The report discusses the design and 10-year performance evaluations of Expanded Polystyrene (EPS) Geofoam embankment constructed for the I-15 Reconstruction Project in Salt Lake City, Utah between 1998 and 2002. It contains methods to evaluate the al...

  8. Adsorption of an endoglucanase from the hyperthermophilic Pyrococcus furiosus on hydrophobic (polystyrene) and hydrophilic (silica) surfaces increases protein heat stability

    NARCIS (Netherlands)

    Koutsopoulos, S.; van der Oost, J.; Norde, Willem

    2004-01-01

    The interaction of an endoglucanase from the hyperthermophilic microorganism Pyrococcus furiosus with two types of surfaces, that is, hydrophobic polystyrene and hydrophilic silica, was investigated, and the adsorption isotherms were determined. The adsorbed hyperthermostable enzyme did not undergo

  9. Directed Self-Assembly of Polystyrene- b -poly(propylene carbonate) on Chemical Patterns via Thermal Annealing for Next Generation Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guan-Wen [MOE Laboratory of; Wu, Guang-Peng [MOE Laboratory of; Chen, Xuanxuan [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States; Xiong, Shisheng [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States; Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States; Arges, Christopher G. [Cain Department; Ji, Shengxiang [Key Laboratory of Polymer Ecomaterials,; Nealey, Paul F. [Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States; Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, United States; Lu, Xiao-Bing [State Key Laboratory of; Darensbourg, Donald J. [Department of Chemistry, Texas A& amp,M University, 3255 TAMU, College Station, Texas 77843, United States; Xu, Zhi-Kang [MOE Laboratory of

    2017-01-23

    Directed self-assembly (DSA) of block copolymers (BCPs) combines advantages of conventional photolithography and polymeric materials and shows competence in semiconductors and data storage applications. Driven by the more integrated, much smaller and higher performance of the electronics, however, the industry standard polystyrene-block-poly(methyl methacrylate) (PS-b-PMM.A) in DSA strategy cannot meet the rapid development of lithography technology because its intrinsic limited Flory-Huggins interaction parameter (chi). Despite hundreds of block copolymers have been developed, these BCPs systems are usually subject to a trade-off between high chi and thermal treatment, resulting in incompatibility with the current nanomanufacturing fab processes. Here we discover that polystyrene-b-poly(propylene carbonate) (PS-b-PPC) is well qualified to fill key positions on DSA strategy for the next-generation lithography. The estimated chi-value for PS-b-PPC is 0.079, that is, two times greater than PS-b-PMMA (chi = 0.029 at 150 degrees C), while processing the ability to form perpendicular sub-10 nm morphologies (cylinder and lamellae) via the industry preferred thermal-treatment. DSA of lamellae forming PS-b-PPC on chemoepitaxial density multiplication demonstrates successful sub-10 nm long-range order features on large-area patterning for nanofabrication. Pattern transfer to the silicon substrate through industrial sequential infiltration synthesis is also implemented successfully. Compared with the previously reported methods to orientation control BCPs with high chi-value (including solvent annealing, neutral top-coats, and chemical modification), the easy preparation, high chi value, and etch selectivity while enduring thermal treatment demonstrates PS-b-PPC as a rare and valuable candidate for advancing the field of nanolithography.

  10. Potential use of scrap expanded polystyrene beads for the control of Aedes triseriatus.

    Science.gov (United States)

    Beehler, J W; DeFoliart, G R

    1991-06-01

    The potential use of expanded polystyrene (EPS) beads for control of Aedes triseriatus was tested in the laboratory and the field. Laboratory studies showed that beads present in amounts which persisted throughout a season significantly reduced the emergence of Ae. triseriatus adults by preventing normal eclosion from the pupae. In the field, tree holes containing EPS beads had significantly fewer larvae present than untreated controls. These field data suggest that EPS beads may mechanically prevent oviposition by mosquitoes.

  11. Electrical and thermal conductivities of reduced graphene oxide/polystyrene composites

    OpenAIRE

    Park, Wonjung; Hu, Jiuning; Jauregui, Luis A.; Ruan, Xiulin; Chen, Yong P.

    2014-01-01

    The author reports an experimental study of electrical and thermal transport in reduced graphene oxide (RGO)/polystyrene (PS) composites. The electrical conductivity (sigma) of RGO/PS composites with different RGO concentrations at room temperature shows a percolation behavior with the percolation threshold of similar to 0.25 vol. %. Their temperature-dependent electrical conductivity follows Efros-Shklovskii variable range hopping conduction in the temperature range of 30-300K. The thermal c...

  12. Plasma etching of polystyrene latex particles for the preparation of graphene oxide nanowalls

    Directory of Open Access Journals (Sweden)

    Bon Bittolo Silvia

    2012-01-01

    Full Text Available Graphene oxide nanowalls were prepared by casting a water dispersion of polystyrene latex particles onto a graphene oxide film followed by tetrafluoromethane plasma etching. Mild plasma etching conditions allow one to retain the oxygen functional groups on the graphene oxide nanowalls. It was found that the exposure to a xenon light source of such graphene oxide nanowalls coated with a gold thin film results in an increase of the electrical conductivity.

  13. Evaluation of the environmental performance of alternatives for polystyrene production in Brazil.

    Science.gov (United States)

    Hansen, Adriana Petrella; da Silva, Gil Anderi; Kulay, Luiz

    2015-11-01

    The global demand for polystyrene is supposed to reach an overall baseline of 23.5 million tons by 2020. The market has experienced the effects of such growth, especially regarding the environmental performance of the production processes. In Brazil, renewable assets have been used to overcome the adverse consequences of this expansion. This study evaluates this issue for the production of Brazilian polystyrene resins, general-purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). The effects of replacing fossil ethylene with a biobased alternative are also investigated. Life Cycle Assessment is applied for ten scenarios, with different technological approaches for renewable ethylene production and an alternative for obtaining bioethanol, which considers the export of electricity. The fossil GPPS and HIPS show a better performance than the partially renewable sources in terms of Climate Change (CC), Terrestrial Acidification (TA), Photochemical Oxidant Formation (POF), and Water Depletion (WD). The exception is Fossil Depletion (FD), a somewhat predictable result. The main environmental loads associated with the renewable options are related to the sugarcane production. Polybutadiene fails to provide greater additional impact to HIPS when compared to GPPS. With regard to obtaining ethylene from ethanol, Adiabatic Dehydration (AD) technology consumes less sugarcane than Adiabatic Dehydration at High Pressure (ADHP), which leads to gains in TA and POF. In contrast, ADHP was more eco-friendly for WD because of its lower water losses and in terms of CC because of the advantageous balance of fossil CO2(eq) at the agricultural stage and the lower consumption of natural gas in ethylene production. The electricity export is an auspicious environmental opportunity because it can counterbalance some of the negative impacts associated with the renewable route. According to a "cradle-to-grave" perspective, the partially renewable resins show a more favorable balance of

  14. Design of bespoke lightweight cement mortars containing waste expanded polystyrene by experimental statistical methods

    OpenAIRE

    Ferrandiz, V; Sarabia, LA; Ortiz, MC; Cheeseman, CR; Garcia-Alcocel, E

    2015-01-01

    This work assesses the reuse of waste expanded polystyrene (EPS) to obtain lightweight cement mortars. The factors and interactions which affect the properties of these mortars were studied by ad-hoc designs based on the d-optimal criterion. This method allows multiple factors to be modified simultaneously, which reduces the number of experiments compared with classical design. Four factors were studied at several levels: EPS type (two levels), EPS content (two levels), admixtures mix (three ...

  15. The Mark-Houwink-Sakurada Equation for the Viscosity of Atactic Polystyrene

    Science.gov (United States)

    Wagner, Herman L.

    1985-10-01

    In this review, the second in a series, the viscosity-molecular weight (Mark-Houwink-Sakurada) relationships have been critically evaluated for atactic polystyrene for a variety of solvents often used for viscosity measurements. These are benzene, toluene, 1,2,4-trichlorobenzene, tetrahydrofuran, o-dichlorobenzene, 2-butanone, and two theta solvents, cyclohexane and decalin. In addition, the Mark-Houwink-Sakurada parameters for several other solvents, not used as frequently, are provided.

  16. “Uncontrolled” Preparation of Disperse Poly(lactide)- block -poly(styrene)- block -poly(lactide) for Nanopatterning Applications

    Energy Technology Data Exchange (ETDEWEB)

    Vanderlaan, Marie E.; Hillmyer, Marc A. (UMM)

    2016-11-08

    We report the facile synthesis of well-defined ABA poly(lactide)-block-poly(styrene)-block-poly(lactide) (LSL) triblock copolymers having a disperse poly(styrene) midblock (Ð = 1.27–2.24). The direct synthesis of telechelic α,ω-hydroxypoly(styrene) (HO-PS-OH) midblocks was achieved using a commercially available difunctional free radical diazo initiator 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]. Poly(lactide) (PLA) end blocks were subsequently grown from HO-PS-OH macroinitiators via ring-opening transesterification polymerization of (±)-lactide using the most common and prevalent catalyst system available, tin(II) 2-ethylhexanoate. Fourteen LSL triblock copolymers with total molar masses Mn,total = 24–181 kg/mol and PLA volume fractions fPLA = 0.15–0.68 were synthesized and thoroughly characterized. The self-assembly of symmetric triblocks was analyzed in the bulk using small-angle X-ray scattering and in thin films using grazing incidence small-angle X-ray scattering and atomic force microscopy. We demonstrate both the bulk and thin film self-assembly of LSL disperse triblocks gave well-organized nanostructures with uniform domain sizes suitable for nanopatterning applications.

  17. Rapid and low-cost fabrication of polystyrene-based molds for PDMS microfluidic devices using a CO2 laser

    KAUST Repository

    Li, Huawei

    2011-11-01

    In this article, we described a rapid and low-cost method to fabricate polystyrene molds for PDMS microfluidic devices using a CO2 laser system. It takes only several minutes to fabricate the polystyrene mold with bump pattern on top of it using a CO2 laser system. The bump pattern can be easily transferred to PDMS and fabricate microchannles as deep as 3μm on PDMS. © (2012) Trans Tech Publications, Switzerland.

  18. The elution of metal cyanocomplexes from polyacrylic - and polystyrene- based ion exchange resins using nitrate and thiocyanate eluants

    OpenAIRE

    Riani,J. C.; Leão,V. A.; Silva, C.A.; Silva, A M; S. M. Bertolino; Lukey,G. C.

    2007-01-01

    Ion exchange resins can potentially be applied in cyanide recycling to address growing environmental concerns over the use of cyanide during gold extraction. In the present work the elution of copper-, iron-, and zinc-cyanocomplexes from polyacrylic- and polystyrene-based resins was studied. It was found that iron and copper cyanides are easily eluted from polyacrylic- and polystyrene-based ion exchange resins using either SCN- or NO3-. However, elution of the zinc cyanide complex from polyst...

  19. Swelling of organoclays in styrene. Effect on flammability in polystyrene nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available In this work the effect of the compatibility between organoclays and styrene on the flammability of polystyrene/clay nanocomposites obtained through in situ incorporation was investigated. The reactions were carried out by bulk polymerization. The compatibility between organoclays and styrene was inferred from swelling of the organoclay in styrene. The nanocomposites were characterized by X-ray diffraction and Transmission Electron Microscopy. The heat release rate was obtained by Cone Calorimeter and the nanocomposites were tested by UL94 horizontal burn test. Results showed that intercalated and partially exfoliated polystyrene/clay nanocomposites were obtained depending on the swelling behavior of the organoclay in styrene. The nanocomposites submitted to UL94 burning test presented a burning rate faster than the virgin polystyrene (PS, however an increase of the decomposition temperature and an accentuated decrease on the peak of heat release of the nanocomposites were also observed compared to virgin PS. These results indicate that PS/clay nanocomposites, either intercalated or partially exfoliated, reduced the flammability approximately by the same extent, although reduced the ignition resistance of the PS.

  20. Characterization of composites based on expanded polystyrene wastes and wood flour.

    Science.gov (United States)

    Poletto, Matheus; Dettenborn, Juliane; Zeni, Mara; Zattera, Ademir J

    2011-04-01

    This paper aims to evaluate the potential for the use of recycled expanded polystyrene and wood flour as materials for the development of wood plastic composites. The effects of wood flour loading and coupling agent addition on the mechanical properties and morphology of wood thermoplastic composites were examined. In addition, a methodology for the thermo-mechanical recycling of expanded polystyrene waste was developed. The results show that the mechanical properties decreased as the wood flour loading increased. On the other hand, the use of poly(styrene-co-maleic anhydride), SMA, as a coupling agent improved the compatibility between the wood flour and polystyrene matrix and the mechanical properties subsequently improved. A morphological study revealed the positive effect of the coupling agent on the interfacial bonding. The density values obtained for the composites were compared with the theoretical values and showed agreement with the rule of mixtures. Based on the findings of this work, it appears that both recycled materials can be used to manufacture composites with high mechanical properties and low density. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Co-release of hexabromocyclododecane (HBCD) and Nano- and microparticles from thermal cutting of polystyrene foams.

    Science.gov (United States)

    Zhang, Haijun; Kuo, Yu-Ying; Gerecke, Andreas C; Wang, Jing

    2012-10-16

    Polystyrene foam is a very important insulation material, and hexabromocyclododecane (HBCD) is frequently used as its flame retardant. HBCD is persistent, bioaccumulative, and toxic, and therefore workplace exposure and environmental emission should be avoided. In this study, we investigated the co-release of HBCD and aerosol particles during the thermal cutting of expanded polystyrene foam (EPS) and extruded polystyrene foam (XPS). The generated particles were simultaneously measured by a fast mobility particle sizer (FMPS) and collected by a cascade impactor (NanoMoudi). In the breathing zone of a cutting worker, the number concentration of aerosol particles was above 1 × 10(12) particles m(-3), and the air concentration of HBCD was more than 50 μg m(-3). Most of the released HBCD was partitioned into particles with an aerodynamic diameter at the nanometer scale. The average concentrations of HBCD in these submicrometer particles generated from the thermal cutting of EPS and XPS were 13 times and 15 times higher than the concentrations in raw foams, respectively. An occupational exposure assessment indicated that more than 60% of HBCD and 70% of particles deposited in the lung of cutting worker would be allocated to the alveolar region. The potential subchronic (or chronic) toxicity jointly caused by the particles and HBCD calls for future studies.

  2. Genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food

    Directory of Open Access Journals (Sweden)

    Makoto Nakai

    2014-01-01

    Full Text Available Here, we conducted in vitro genotoxicity tests to evaluate the genotoxicity of styrene oligomers extracted from polystyrene intended for use in contact with food. Styrene oligomers were extracted with acetone and the extract was subjected to the Ames test (OECD test guideline No. 471 and the in vitro chromosomal aberration test (OECD test guideline No. 473 under good laboratory practice conditions. The concentrations of styrene dimers and trimers in the concentrated extract were 540 and 13,431 ppm, respectively. Extraction with acetone provided markedly higher concentrations of styrene oligomers compared with extraction with 50% ethanol aqueous solution, which is the food simulant currently recommended for use in safety assessments of polystyrene by both the United States Food and Drug Administration and the European Food Safety Authority. And these high concentrations of styrene dimers and trimers were utilized for the evaluation of genotoxicity in vitro. Ames tests using five bacterial tester strains were negative both in the presence or absence of metabolic activation. The in vitro chromosomal aberration test using Chinese hamster lung cells (CHL/IU was also negative. Together, these results suggest that the risk of the genotoxicity of styrene oligomers that migrate from polystyrene food packaging into food is very low.

  3. Reduction of Listeria monocytogenes biofilms on stainless steel and polystyrene surfaces by essential oils.

    Science.gov (United States)

    Desai, Monil A; Soni, Kamlesh A; Nannapaneni, Ramakrishna; Schilling, M Wes; Silva, Juan L

    2012-07-01

    Plant-derived essential oils were tested for their ability to eliminate biofilms of Listeria monocytogenes on polystyrene and stainless steel surfaces. Various concentrations of essential oils were tested with different contact times on biofilms of various ages. Preliminarily screening of nine essential oils and related phenolic compounds in a disk diffusion assay revealed that thyme oil, oregano oil, and carvacrol had the highest antimicrobial activity. Further screening of these three compounds against 21 L. monocytogenes strains representing all 13 serotypes indicated some strain-specific variations in antimicrobial activity. For 1-day-old biofilms of mixed L. monocytogenes strains produced at 22°C on polystyrene microtiter plates, only 0.1% concentrations of thyme oil, oregano oil, and carvacrol were needed to eliminate 7 log CFU per well. On the stainless steel coupons, a 0.5% concentration of these compounds was adequate to completely eliminate 4-day-old biofilms at 7 log CFU per coupon. Our findings indicate that these compounds are potential candidates for elimination of L. monocytogenes biofilms on stainless steel and polystyrene surfaces.

  4. Electrospinning fabrication and oxygen sensing properties of Cu(I) complex-polystyrene composite microfibrous membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Liyan, E-mail: wanglykmmc@163.co [Department of Orthodontics, School of Stomatology, Fourth Military Medical University, XiAn (China); Xu Yun [Department of Orthodontics, School of Stomatology, KunMing Medical College, Kunming (China); Lin Zhu [Department of Orthodontics, School of Stomatology, Fourth Military Medical University, XiAn (China); Zhao Ning [Department of Orthodontics, School of Stomatology, West China College, SiChuan University, ChengDu (China); Xu Yanhua [Department of Orthodontics, School of Stomatology, KunMing Medical College, Kunming (China)

    2011-07-15

    In this paper, a phosphorescent Cu(I) complex of [Cu(POP)(ECI-Phen)]BF{sub 4}, where POP=bis[2-(diphenylphosphino)phenyl]ether, and ECI-Phen=1-ethyl-2-(N-ethyl-carbazole-yl-4-)imidazo[4,5-f]1,10-phenanthroline, is incorporated into a polystyrene matrix of polystyrene (PS) to form microfibers membranes. The possibility of using the resulted composite microfibrous membranes as an optical oxygen sensor is explored. Good linearity and short response time are obtained with a sensitivity of 9.8. These results suggest that phosphorescent [Cu(POP)(ECI-Phen)]BF{sub 4} is a promising candidate for oxygen-sensors and PS is an excellent matrix for oxygen sensing material because it owns a large surface-area-to-volume ratio and can supply a homogeneous matrix for probe molecules. Further analysis suggests that the molecular structure of diamine ligand in Cu(I) complexes is critical for sensitivity due to the characteristic electronic structure of excited state Cu(I) complexes. - Highlights: {yields} Cu(I) complex is incorporated into polystyrene matrix to form nanofibers. {yields} Resulted sample exhibit good linearity and short response time. {yields} PS is an excellent matrix for oxygen sensing material for probe molecules. {yields} Molecular structure of diamine ligand is critical for sensitivity.

  5. Magnetic studies of polystyrene/iron-filled multi-wall carbon nanotube composite films

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, T.L., E-mail: Tatyana.makarova@lut.fi [Lappeenranta University of Technology, FI-53851 Lappeenranta (Finland); Ioffe Institute, St Petersburg 194021 (Russian Federation); Zakharchuk, I.; Geydt, P.; Lahderanta, E. [Lappeenranta University of Technology, FI-53851 Lappeenranta (Finland); Komlev, A.A. [St Petersburg State Electrotechnical University, St Petersburg 197376 (Russian Federation); Zyrianova, A.A. [Ioffe Institute, St Petersburg 194021 (Russian Federation); Kanygin, M.A. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Sedelnikova, O.V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Suslyaev, V.I [Tomsk State University, Tomsk 634050 (Russian Federation); Bulusheva, L.G.; Okotrub, A.V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation)

    2016-10-01

    Polystyrene/iron-filled multi-wall carbon nanotube composite films were prepared by solution processing, forge-rolling and stretching methods. Elongated iron carbide nanoparticles formed because of catalytic growth are situated inside the hollow cavity of the nanotubes. Magnetic susceptibility measurements as well as records of isothermal hysteresis loops performed in three perpendicular directions of magnetic field confirmed that the nanotubes have a preferential alignment in the matrix. Strong diamagnetic anisotropy in the composites emerges not only from the MWCNTs but also from the polystyrene matrix. The polymer sticks to the honeycomb lattice through the interaction of the π-orbitals of the phenyl ring and those of the carbon nanotube, contributing to anisotropic diamagnetic response. The contribution of iron nanoparticles to overall magnetic response strongly depends on nanotube concentration in the composite as well as on matrix-filler non-covalent stacking, which influences magnetic interparticle interactions. - Highlights: • . Nanotube/polystyrene composites were prepared by stretching and forge-rolling methods. • Anisotropic response of the composites mainly comes from the phenyl aromatic rings. • Magnetism of iron-based nanoparticles is governed by interactions with the matrix.

  6. Constructing robust and functional micropatterns on polystyrene surfaces by using deep UV irradiation.

    Science.gov (United States)

    Palacios, Marta; García, Olga; Rodríguez-Hernández, Juan

    2013-02-26

    We report the preparation of different surface patterns based on the photo-cross-linking/degradation kinetics of polystyrene (PS) by using UV light. Upon exposure to UV light, PS can be initially cross-linked, whereas an excess of the exposure time or intensity provokes the degradation of the material. Typically photolithography employs either positive or negative photoresist layers that upon removal of either the exposed or the nonexposed areas transfer the pattern of the mask. Herein, we present a system that can be both negative and positive depending on several aspects, including the irradiation time, intensity, or presence of absorbing active species (photoinitiators) using a general setup. As a result of the optimization of the time of exposure and the use of an appropriate cover or the incorporation of an appropriate amount of photoinitiator (in this particular case IRG 651), different tailor-made surface patterns can be obtained. Moreover, changes of the chemical composition of the polystyrene using, for instance, block copolymers can lead to surface patterns with variable functional groups. In this study we describe the formation of surface patterns using polystyrene-block-poly(2,3,4,5,6-pentafluorostyrene) block copolymers. The introduction of fluorinated moieties clearly modifies the wettability of the films when compared with that of the same structures obtained with PS. As a consequence we present herein a patterning methodology that can simultaneously vary not only the morphology but also the surface chemical composition.

  7. Nitroxide mediated and atom transfer radical graft polymerization of atactic polymers onto syndiotactic polystyrene

    Directory of Open Access Journals (Sweden)

    M. Abbasian

    2012-06-01

    Full Text Available 'Living' radical graft polymerization was employed to prepare graft copolymers with nitroxide-mediated arylated syndiotactic polystyrene as the backbone and polystyrene (PS, poly(p-methylstyrene (PMS and poly(methylmethacrylate (PMMA as branches. A two-stage process has been developed to synthesize the macroinitiator. First, syndiotactic polystyrene (sPS was modified by the Friedel-Crafts reaction to introduce chlorine; second, the chlorine groups were converted to nitroxide mediated groups by coupling with 1-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO-OH. The resulting macroinitiator (sPS-TEMPO for 'living' free radical polymerization was then heated in the presence of styrene and p-methylstyrene to form graft and block copolymers. We used the obtained copolymer and N-bromosuccinimide as brominating agent to achieve polymers with bromine groups. This brominated copolymer was used as a macroinitiator for polymerizing methyl methacrylate in the presence of the CuBr/bpy catalyst system. The formation of the graft and block copolymers was confirmed by DSC, ¹H NMR and FTIR spectroscopy. This approach using macroinitiators is an effective method for the preparation of new materials.

  8. Polystyrene nanoparticles facilitate the internalization of impermeable biomolecules in non-tumour and tumour cells from colon epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, Laura [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain); Cano-Cortés, Victoria; Rodríguez, María J. [University of Granada, Department of Pharmaceutical and Organic Chemistry (Spain); Vélez, Celia; Melguizo, Consolación, E-mail: melguizo@ugr.es [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain); Sánchez-Martín, Rosario M., E-mail: rmsanchez@ugr.es [University of Granada, Department of Pharmaceutical and Organic Chemistry (Spain); Prados, Jose [University of Granada, Department of Human Anatomy and Embryology, Institute of Biopathology and Regenerative Medicine (IBIMER) (Spain)

    2015-01-15

    Advanced colon cancer has a poor prognosis due to the limited effectiveness of current chemotherapies. Treatment failures may be avoided by the utilization of nanoparticles, which can enhance the effects of antitumor drugs, reduce their side effects and increase their directionality. Polystyrene nanoparticles have shown high biocompatibility and appropriate physicochemical properties and may represent a novel and more effective approach against colon cancer. In the present study, polystyrene nanoparticles were synthesized and fluorescently labelled, analyzing their cell internalization, intracellular localization and capacity to release transported molecules in tumour and non-tumour human colon cell lines (T84 and CCD-18). Flow cytometry and fluorescence microscopy studies demonstrated that polystyrene nanoparticles are an effective vehicle for the intracellular delivery of small molecules into colon epithelium cells. The percentage cell uptake was around 100 % in both T84 and CCD-18 cell lines after only 24 h of exposure and was cell confluence-independent. The polystyrene nanoparticles showed no cytotoxicity in either colon cell line. It was found that small molecules can be efficiently delivered into colon cells by using a disulphide bridge as release strategy. Analysis of the influence of the functionalization of the polystyrene nanoparticles surface on the internalization efficiency revealed some morphological changes in these cells. These results demonstrate that polystyrene nanoparticles may improve the transport of biomolecules into colon cells which could have a potential application in chemotherapeutic treatment against colon cancer.

  9. Migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene containers and discrimination of these two kinds of polystyrene by principal component analysis.

    Science.gov (United States)

    Lin, Qin-Bao; Song, Xue-Chao; Fang, Hong; Wu, Yu-Mei; Wang, Zhi-Wei

    2017-01-01

    The migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene (EPS) containers into isooctane was investigated using gas chromatography-mass spectrometry (GC-MS). EPS containers were in two-sided contact with isooctane at temperatures of 25 and 40°C. It was shown that recycled EPS gave greater migration ratios compared with virgin EPS, which indicated that styrene and ethylbenzene migrated more easily from recycled EPS. In addition, an analytical method to distinguish between virgin and recycled EPS containers was established by GC-MS followed by principal component analysis (PCA). The relative peak area of the identified compounds was used as input data for PCA. Distinct separation between virgin and recycled EPS was achieved on a score plot. Extension of this method to other plastics may be of great interest for recycled plastics identification.

  10. Self-assembly of poly(vinylidene fluoride–polystyrene block copolymers in solution: Effects of the length of polystyrene block and solvent compositions

    Directory of Open Access Journals (Sweden)

    Yao Wu

    2017-09-01

    Full Text Available We report the first preliminary and extensive study on the solution self-assembly behaviors of poly(vinylidene fluoride–b-polystyrene (PVDF–PS block copolymers. The two PVDF–PS polymers we examined have the same length of PVDF block with number averaged repeating unit of 180, but distinctly different lengths of PS block with number averaged repeating unit of 125 and 1202. The self-assembly experiments were carried out in a series of mixture solutions containing a good solvent N,N-dimethylformamide and a selective solvent with different ratios. Our results showed that the self-assembly process was greatly affected by the two factors we examined, i.e. the length of the PS block and the solvent composition. We hope that our study could stimulate more research on the self-assembly of PVDF-containing polymers in solution.

  11. Reduced-order molecular-dynamics model for polystyrene by equivalent-structure coarse graining.

    Science.gov (United States)

    Srivastava, Anand; Ghosh, Somnath

    2012-02-01

    This paper develops a reduced-order equivalent-structure based model for polystyrene in a rigid body molecular dynamics framework. In general, a coarse-grained model for polymers is obtained by replacing a group of chemically connected atoms by an effective particle and deriving a coarse-grained interaction potential that reproduces the structure and dynamics at the desired length and time scale. In the current model, a detailed (~16 atoms) polystyrene monomer referred to as basic structural element (BSE) is replaced by an equivalent model with spherical backbone particles and an ellipsoidal particle that represents the styrene sidegroup. The governing principals of this homogenization is based on the mass, centroid, angular momentum, and energy equivalence between the detailed and the proposed reduced-order model. The bonded interactions parameters are readily obtained in the optimization of the equivalent structure from the detailed representation. The nonbonded interactions are treated separately. In order to capture the stereochemistry of the polystyrene molecule, an anisotropic biaxial nonbonded interaction potential function known as RE-squared (RE2) interaction has been used between pairs of ellipsoidal and/or spherical particles in the system. The required calibration of the nonbonded parameters is carried out by matching with the experimental density and the local structure using radial distribution function. This homogenization process scales up the modeling system size significantly as the higher frequency motions like -C-H- vibrations and sidegroup movements are suppressed. The accuracy of the model is established by comparing fine-scale simulation with explicit representations.

  12. Preparation, electrochemical characterization and antibacterial study of polystyrene-based magnesium-strontium phosphate composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Mohammad Mujahid Ali; Rafiuddin,, E-mail: rafi_amu@rediffmail.com

    2012-07-01

    The electrochemical characterizations of polystyrene-based magnesium-strontium phosphate (MSP) composite membrane have been worked on, as a function of membrane thickness, porosity and moisture content etc. Polystyrene-based magnesium-strontium phosphate composite membrane was characterized by XRD, FTIR, SEM, and antibacterial studies. The membrane was found to be crystalline in nature with uniform arrangement of particles, no sign of visible cracks and shows excellent inhibitory results against Escherichia coli and Pseudomonas aeruginosa bacteria. The membrane potentials of inorganic membrane were measured with uni-univalent electrolytes solution using saturated calomel electrodes and followed the order LiCl > NaCl > KCl, thus, the membrane was found to be cation selective. Membrane potential data have been used to calculate transport number, mobility ratio, distribution coefficient, charge effectiveness, and also to derive the fixed-charge density which is a central parameter governing the membrane phenomena by utilizing the Teorell, Meyer, and Sievers method. The order of surface charge density for uni-univalent electrolytes solution was found to be LiCl < NaCl < KCl. - Graphical abstract: Plots of membranes potential (mV) versus - log C{sub 2} (mol/l) at different concentrations of KCl electrolyte solution for polystyrene-based MSP composite membranes prepared at different pressures of 100-160 MPa. Highlights: Black-Right-Pointing-Pointer The membrane was found to be crystalline in nature. Black-Right-Pointing-Pointer Membrane potential of electrolytes followed the order LiCl > NaCl > KCl. Black-Right-Pointing-Pointer The order of surface charge density was found to be LiCl < NaCl < KCl. Black-Right-Pointing-Pointer The membrane show excellent results against E. coli and P. aeruginosa bacteria.

  13. Echicetin coated polystyrene beads: a novel tool to investigate GPIb-specific platelet activation and aggregation.

    Directory of Open Access Journals (Sweden)

    Alexey Navdaev

    Full Text Available von Willebrand factor/ristocetin (vWF/R induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways.

  14. Investigations of crystallization and ionic interactions of sulfonated syndiotactic polystyrene ionomers

    Science.gov (United States)

    Gummaraju, Raghuram

    2000-10-01

    Syndiotactic polystyrene (sPS) is a semicrystalline polymer that crystallizes rapidly and exhibits several polymorphic crystal structures. Crystallization of sPS from the melt results in an all-trans chain conformation comprised of alpha (hexagonal unit cell) and beta (orthorhombic unit cell) crystal forms. Crystallization of sPS from solution produces helical crystal structures. To ascertain the link between ionic aggregation and crystallization in semicrystalline ionomers, sulfonated syndiotactic polystyrene (SsPS) has been selected as a model system. 23Na SSNMR (Solid-state NMR) spectra have also been utilized to analyze the influence of a surfactant (i.e., dodecyl benzene sodium sulfonate (DBSNa)) on the state of ionic aggregation. Increasing the surfactant content within SsPS ionomers caused a downfield shift coupled with a decrease in width, for the peak corresponding to the ionic aggregates. Added DBSNa molecules can disrupt interactions within the ionic aggregates and consequently weaken the electrostatic network in SsPS. The influence of nonpolar/polar additives on syndiotactic polystyrene was also evaluated utilizing isothermal crystallization, 23Na SSNMR, 13C CPMAS (Cross-polarization Magic-angle spinning) NMR and WAXD (Wide-angle X-ray Diffraction) investigations. To evaluate the influence of crystallization on ionic aggregation in SsPS ionomers, 23Na and 13C SSNMR techniques have been utilized. Polymorphic nature was not significantly affected by the incorporation of ionic groups, as indicated by the identical 13C spectra for sPS and SsPS polymers. A densification of the crystalline domains is likely to affect the conformations of amorphous chains attached to the crystallite surfaces. This perturbation in chain conformation may then result in a disruption of the state of ionic aggregation. The retention of the state of ionic aggregation within SaPS upon annealing clearly indicates that the disruption in the ionic domains of the SsPS ionomer originates

  15. Cationic polystyrene nanospheres induce autophagic cell death through the induction of endoplasmic reticulum stress

    Science.gov (United States)

    Chiu, Hui-Wen; Xia, Tian; Lee, Yu-Hsuan; Chen, Chun-Wan; Tsai, Jui-Chen; Wang, Ying-Jan

    2014-12-01

    Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung epithelial (BEAS-2B) cells. Furthermore, NH2-PS could induce autophagic cell death. NH2-PS increased autophagic flux due to reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress caused by misfolded protein aggregation. The inhibition of ER stress decreased cytotoxicity and autophagy in the NH2-PS-treated cells. In addition, the Akt/mTOR and AMPK signaling pathways were involved in the regulation of NH2-PS-triggered autophagic cell death. These results suggest an important role of autophagy in cationic NP-induced cell death and provide mechanistic insights into the inhibition of the toxicity and safe material design.Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung

  16. A reactive polystyrene-block-polyisoprene star copolymer as a toughening agent in an epoxy thermoset

    KAUST Repository

    Francis, Raju

    2015-12-29

    © 2015 Springer-Verlag Berlin Heidelberg A polystyrene-block-polyisoprene ((PS-b-PI)3) star polymer was synthesized by photochemical reversible addition fragmentation chain transfer (RAFT) polymerization. The obtained star polymer was epoxidized and used as a toughening agent in an epoxy thermoset. The incorporation of the epoxidized star polymer resulted in the formation of nanostructures and it was fixed by a crosslinking reaction. The formation of nanostructures in the thermosets follows the mechanism of reaction-induced microphase separation. The mechanical properties such as toughness and tensile strength were considerably increased due to the nanostructures formed by reactive blending.

  17. Design of Nanohybrid Systems from a Partially Fluorinated Organogelator and Syndiotactic Polystyrene Thermoreversible Gel.

    Science.gov (United States)

    Khan, Ahmad Nawaz; Schmutz, Marc; Lacava, Johann; Al Ouahabi, Abdelaziz; Nguyen, Thi-Thanh-Tam; Mesini, Philippe J; Guenet, Jean-Michel

    2015-07-14

    Nanohybrid systems are prepared from organogels of a partially fluorinated molecule and from thermoreversible gels of syndiotactic polystyrene. The thermodynamic behavior, morphology, and structure are investigated by using differential scanning calorimetry, atomic force microscopy, small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS). The outcomes of these investigations suggest that the fibrils of the organogel coil around the sPS fibrils, probably through a heterogeneous nucleation process. These systems therefore differ from previously investigated sPS/OPV systems (oligo vinylene phenylene) where OPV fibrils pervade the sPS network.

  18. Elongational viscosity of narrow molar mass distribution star and pom-pom polystyrene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Hassager, Ole

    2006-01-01

    We have measured the transient and steady uniaxial elongational viscosity, using the filament stretching rheometer (FSR), of two narrow molar mass distribution (MMD) long-chain branched polystyrene melts: AnBAm (a ‘pom-pom’ molecule) and AnB (a ‘asymmetric star’ molecule). The elongational...... viscosities for the 'pom-pom' molecule are separable in time and strain for times less than the reptation time. Separability was not observed in the elongational viscosities for the ‘asymmetric star’ molecule....

  19. Enhanced Thermal and Electrical Properties of Polystyrene-Graphene Nanofibers via Electrospinning

    Directory of Open Access Journals (Sweden)

    Yan Li

    2016-01-01

    Full Text Available Polystyrene- (PS- graphene nanoplatelets (GNP (0.1, 1, and 10 wt.% nanofibers were successfully produced via electrospining of dimethyformamide- (DMF- stabilized GNP and PS solutions. Morphological analysis of the composite nanofibers confirmed uniform fiber formation and good GNP dispersion/distribution within the PS matrix. The good physical properties of GNP produced by liquid exfoliation were transferred to the PS nanofibers. GNP modified PS nanofibers showed a 6-fold increase in the thermal conductivity and an increase of 7-8 orders of magnitude in electrical conductivity of the nanofibers at 10 wt.% GNP loading.

  20. Preparation of polystyrene-poly(ethylene glycol) diblock copolymer by "living" free radical polymerization

    DEFF Research Database (Denmark)

    Chen, Xianyi; Gao, Bo; Kops, Jørgen

    1998-01-01

    Amphiphilic diblock copolymer containing segments of polystyrene and monomethoxypoly(ethylene glycol) (PS-b-PEG) was synthesised by a novel method. Initially, the adduct (BZ-TEMPO) obtained by reacting benzoyl peroxide, styrene, and 2,2,6,6-tetramethyl-piperidinyl-1-oxy (TEMPO) was isolated...... terminated with a TEMPO unit (MPEG-TEMPO), which was further used to prepare the diblock copolymer PS-b-PEG by 'living' free radical polymerisation of styrene. The product was purified and identified by H-1 n.m.r. and GPC. However, large amounts of homopolystyrene was also formed by simultaneous thermal...

  1. The co-pyrolysis of flame retarded high impact polystyrene and polyolefins

    OpenAIRE

    Hall, W.J.; Bhaskar, T.; Williams, P.T.; Mitan, N.; Muto, A.; Sakata, Y.

    2007-01-01

    The co-pyrolysis of brominated high impact polystyrene (Br-HIPS) with polyolefins using a fixed bed reactor has been investigated, in particular, the effect that different types brominated aryl compounds and antimony trioxide have on the pyrolysis products. The pyrolysis products were analysed using FT-IR, GC-FID, GC-MS, and GC-ECD. Liquid chromatography was used to separate the oils/waxes so that a more detailed analysis of the aliphatic, aromatic, and polar fractions could be carried out. I...

  2. Preparative frontal size-exclusion chromatography of mineral ions on neutral hypercrosslinked polystyrene.

    Science.gov (United States)

    Davankov, Vadim; Tsyurupa, Maria

    2005-09-16

    Hypercrosslinked polystyrene, being the first and the only one accessible for water microporous hydrophobic polymeric sorbent, was found to provide efficient separation of inorganic electrolytes under conditions of a frontal size-exclusion chromatography (SEC). The process, based on the difference in size of hydrated competing ions, permits separations of many pairs of salts, acids, and bases. The productivity of separation increases with the concentration of the feed solution rising. Remarkably, concentrations of the separated components in corresponding fractions may substantially exceed those in the initial mixture, which can be explained in terms of a conception of an ideal separation process.

  3. The use of dielectric spectroscopy for the characterization of polymer-induced flocculation of polystyrene particles

    DEFF Research Database (Denmark)

    Christensen, Peter Vittrup; Keiding, Kristian

    2008-01-01

    in dilute suspensions. Thus, techniques usable for flocculation characterization in high-solids suspensions are desirable. This study investigates the use of dielectric spectroscopy to monitor the flocculation of polystyrene particles with a cationic polymer. The frequency-dependent permittivity is modeled...... as a decrease in the magnitude of the dielectric dispersion. The use of dielectric spectroscopy is found to be valuable for assessing flocculation processes in high-solids suspensions, as changes in parameters Such as floc size and charge can be detected....

  4. Properties of the Ukrainian Polystyrene-Based Plastic Scintillator UPS 923A

    CERN Document Server

    Artikov, A M; Chirikov-Zorin, I E; Chokheli, D; Lyablin, M; Bellettini, G; Menzione, A; Tokar, S; Giokaris, N; Manousakis-Katsikakis, A

    2005-01-01

    The polystyrene-based scintillator UPS 923A was chosen for upgrading of the muon system for the CDF detector at the Fermilab Tevatron. Properties of this scintillator such as light output, light attenuation, long-term stability and also timing characteristics of scintillator and wavelength shifting fibers were investigated. The method for the Bulk Attenuation Length measurements of the scintillator to its own light emitted was proposed. Comparative measurements of the characteristics of the UPS 923A and the polyvinyltoluene-based scintillator NE 114 were performed. It was found that natural aging of the NE 114 was two times faster than that of the UPS 923A.

  5. Ileocolic Perforation Secondary to Sodium Polystyrene Sulfonate in Sorbitol Use: A Case Report

    Directory of Open Access Journals (Sweden)

    Vincent Trottier

    2009-01-01

    Full Text Available Hyperkalemia is a common condition encountered in medical and surgical patients. It can lead to various complications including cardiac arrhythmias. Sodium polystyrene sulfonate (SPS in sorbitol is an ion-exchange resin that can be used to treat hyperkalemia. It can be used in enema or in oral form. The present article describes the case of an intensive care unit patient who experienced severe, diffuse, intestinal perforation induced by the use of SPS-sorbitol, requiring multiple laparotomies, followed by a brief review of the relevant literature and recommendations regarding the use of SPS-sorbitol.

  6. Characterisation of recycled acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil.

    Science.gov (United States)

    Hirayama, Denise; Saron, Clodoaldo

    2015-06-01

    Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers. © The Author(s) 2015.

  7. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    Directory of Open Access Journals (Sweden)

    Yin-lin Lei

    2014-07-01

    Full Text Available With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB in the alloy particles on the feasibility of the membrane formation are discussed. The results indicate that a favorable sulfonation degree above 80% and a suitable ion exchange capacity of 1.5–2.4 mmol/g can be gained, with concentrated sulfuric acid as the sulfonation agent and 1,2-dichloroethane as the swelling agent. The running electrical resistance and desalination effect of the prepared cation exchange membrane were measured in a pilot-scale electrodialyser and not only obviously exceeded a commercial heterogeneous cation exchange membrane, but was also very close to a commercial homogenous membrane. In this way, the authors have combined the classical sulfonation method of polystyrene-based cation exchange resins with the traditional thermoforming manufacturing process of heterogeneous cation exchange membranes, to successfully develop a novel, low-price, but relatively high-performance polystyrene/PVDF cation exchange membrane with the semi-IPN structure.

  8. Syntheses, Magnetic and Spectral Studies on the Coordination Compounds of the Polystyrene-anchored Thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2012-01-01

    Full Text Available The reaction between polystyrene 3-formylsalicylate and thiophene-2-carboxylic acid hydrazide in DMF in the presence of ethyl acetate results in the formation of polystyrene N-(2-carbamoylthienyl-3'-carboxy-2'-hydroxybenzylideneimine (I. A benzene suspension of I reacts with mercaptoacetic acid and forms the polystyrene N-(2-carbamoylthienyl-C-(3'-carboxy-2'-hydroxyphenyl thiazolidin-4-one, PSCH2–LH2 (II. A DMF suspension of II reacts with Zn(II, Co(II, Cu(II, Zr(OH2(IV and MoO2(VI ions and forms the corresponding polystyrene-anchored coordination compounds, [PSCH2–LZn(DMF] (III, [PSCH2–LCo(DMF3] (IV, [PSCH2–LHCu(OAc] (V, [PSCH2–LH2Zr(OH2(OAc2] (VI and [PSCH2–LHMoO2(acac] (VII respectively. The polystyrene-anchored coordination compounds have been characterized on the basis of elemental analyses, spectral (IR, reflectance, ESR studies and magnetic susceptibility measurements. II acts as a neutral tridentate ONS donor ligand in VI, a monobasic bidentate OS donor ligand in VII, a monobasic tridentate ONS donor ligand in V and a dibasic tridentate ONO donor ligand in III and IV. The acetato groups behave as monodentate ligands in V and VI. A square-planar structure for V, a tetrahedral structure for III, an octahedral structure for IV and VII and a pentagonal-bipyramidal structure for VI are suggested.

  9. Degradability of coconut fibre coated with polystyrene in an alkaline medium=Degradability of coconut fibre coated with polystyrene in an alkaline medium

    Directory of Open Access Journals (Sweden)

    Fermin Garcia Velasco

    2016-02-01

    Full Text Available The surface of plant fibre consists mainly of compounds such as cellulose, hemicellulose, lignin, pectin and extractives. These organic compounds are sensitive to the action of many chemical agents and to basic pH, which hinders their use in cementitious composites to make them more sustainable. The aim of this work was to evaluate the efficiency of polystyrene (0, 1, 3 and 5%, plus 3% and heat treatment at 140°C on the protection of coconut fibre in an alkaline medium. The fibres were submersed in an alkaline solution (pH 14 for a total of 63 days, and were periodically evaluated by gravimetric analysis. At the end of the test, the fibres were analysed by scanning electron microscopy. According to the analysis, the sample of coconut fibre with no protective coating lost 80% of its initial weight and, through scanning electron microscopy, it was possible to see the destruction of the surface structure of the fibre, exposing the beams of cellulose microfibres located in the inner regions. The coconut fibres with a 3% polystyrene coating together with heat treatment ended the test with a percentage final weight greater than 50% of the initial weight. A polystyrene coating (3% followed by heat treatment at 140°C improved durability in the coconut fibres by approximately 30%, when immersed in an alkaline medium. =A superfície da fibra vegetal é constituída principalmente por compostos como celulose, hemicelulose, lignina, pectina e extrativos. Esses compostos orgânicos são sensíveis à ação de muitos agentes químicos e ao pH básico, o que dificulta seu emprego em compósitos cimentícios para torná-los mais sustentáveis. Objetivou-se com este trabalho avaliar a eficiência do poliestireno (0, 1, 3 , 5% e 3% mais tratamento térmico a 140 °C na proteção da fibra de coco em meio alcalino. As fibras ficaram imersas em solução alcalina (pH 14 em um total de 63 dias e foram avaliadas periodicamente por meio de ensaio gravimétrico. Ao

  10. Studies on the rubber phase stability in gamma irradiated polystyrene-SBR blends by using FT-IR and Raman spectroscopy[Gamma irradiation; Polystyrene-SBR blends; Izod impact; FTIR; Raman

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Barrera, G.; Lopez, H.; Castano, V.M.; Rodriguez, R. E-mail: rogelior@servidor.unam.mx

    2004-02-01

    Improvement in the impact properties of polystyrene-SBR blends produced by different concentrations and types of styrene-butadiene rubber (SBR) was studied. The samples were gamma irradiated at different doses to achieve good adhesion, and consequently good stability, between the rubbery phase and the polystyrene matrix, producing an improvement in the impact properties. The results show that the best Izod impact was obtained for a blend with 10% SBR and with a dose of 100 kGy. Several samples with 0%, 3%, 5% and 10% of SBR were prepared and characterized by FT-IR and FT-Raman spectroscopies.

  11. Ionoluminescence properties of polystyrene-hosted fluorophore films induced by helium ions of energy 50-350 keV

    Science.gov (United States)

    Chakraborty, Subha; Huang, Mengbing

    2017-10-01

    We report on measurements and analysis of ionoluminescence properties of pure polystyrene films and polystyrene films doped with four types of fluorophores in low kinetic energies (50-350 keV) of ion irradiation. We have developed a theoretical model to understand the experimentally observed ionoluminescence behaviors in terms of scintillation yield from individual ion tracks, photophysical energy transfer mechanisms, and irradiation-induced defects. A comparison of the model and experimental results suggests that singlet up-conversion resulting from triplet-triplet annihilation processes may be responsible for enhanced singlet emission of the fluorophores at high ion beam flux densities. Energy transfer from the polystyrene matrix to the fluorophore molecules has been identified as an effective pathway to increasing the fluorescence efficiency in the doped scintillator films.

  12. Ferroferric oxide/polystyrene (Fe3O4/PS superparamagnetic nanocomposite via facile in situ bulk radical polymerization

    Directory of Open Access Journals (Sweden)

    2010-03-01

    Full Text Available Organo-modified ferroferric oxide superparamagnetic nanoparticles, synthesized by the coprecipitation of superparamagnetic nanoparticles in presence of oleic acid (OA, were incorporated in polystyrene (PS by the facile in situ bulk radical polymerization by using 2,2-azobisisobutyronitrile (AIBN as initiator. The transmission electron microscopy (TEM analysis of the resultant uniform ferroferric oxide/polystyrene superparamagnetic nanocomposite (Fe3O4/PS showed that the superparamagnetic nanoparticles had been dispersed homogeneously in the polymer matrix due to the surface grafted polystyrene, confirmed by Fourier transform infrared (FT-IR spectroscopy and thermogravimetric analysis (TGA. The superparamagnetic property of the Fe3O4/PS nanocomposite was testified by the vibrating sample magnetometer (VSM analysis. The strategy developed is expected to be applied for the large-scale industrial manufacturing of the superparamagnetic polymer nanocomposite.

  13. Spectroscopic study of the charge-transfer complexes TiCl4/styrene and TiCl4/polystyrene

    Science.gov (United States)

    Gonçalves, Norberto S.; Noda, Lúcia. K.

    2017-10-01

    In this work, solutions of TiCl4/styrene and TiCl4/polystyrene charge-transfer complexes in CHCl3 or CDCl3 were investigated by UV-vis, resonance Raman and 1H NMR spectroscopies in order to study their molecular and electronic structures. Both show a yellow colour due to absorption in the 400 nm region, related to a charge-transfer transition. In Raman spectra, as the excitation approaches the resonance region, the primary enhancement of aromatic ring modes was mainly observed, rather than intensification of the vinylic double-bond stretch. Under the experimental conditions it was observed that formation of polystyrene takes place, as showed by 1H NMR spectra, and the most significant interaction occurs at the aromatic ring, as supported by the results from interaction of TiCl4 with polystyrene, as indicated by the charge-transfer band and resonant intensification of the aromatic ring modes.

  14. Modeling of the phase equilibria of polystyrene in methylcyclohexane with semi-empirical quantum mechanical methods I

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2003-01-01

    A method for calculating interaction parameters traditionally used in phase-equilibrium computations in low-molecular systems has been extended for the prediction of solvent activities of aromatic polymer solutions (polystyrene+methylcyclohexane). Using ethylbenzene as a model compound for the re......A method for calculating interaction parameters traditionally used in phase-equilibrium computations in low-molecular systems has been extended for the prediction of solvent activities of aromatic polymer solutions (polystyrene+methylcyclohexane). Using ethylbenzene as a model compound...... energies are determined for three molecular pairs, the solvent and the model molecule, two solvent molecules and two model molecules, and used to calculated UNIQUAC interaction parameters, a(ij) and a(ji). Using these parameters, the solvent activities of the polystyrene 90,000 amu+methylcyclohexane system...

  15. Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes.

    Science.gov (United States)

    Blumenstein, Nina J; Hofmeister, Caroline G; Lindemann, Peter; Huang, Cheng; Baier, Johannes; Leineweber, Andreas; Walheim, Stefan; Wöll, Christof; Schimmel, Thomas; Bill, Joachim

    2016-01-01

    In this study we investigated the influence of an organic polystyrene brush on the deposition of ZnO thin films under moderate conditions. On a non-modified SiO x surface, island growth is observed, whereas the polymer brush induces homogeneous film growth. A chemical modification of the polystyrene brushes during the mineralization process occurs, which enables stronger interaction between the then polar template and polar ZnO crystallites in solution. This may lead to oriented attachment of the crystallites so that the observed (002) texture arises. Characterization of the templates and the resulting ZnO films were performed with ζ-potential and contact angle measurements as well as scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD). Infrared spectroscopy (IR) measurements were used to investigate the polystyrene brushes before and after modification.

  16. Chemical bath deposition of textured and compact zinc oxide thin films on vinyl-terminated polystyrene brushes

    Directory of Open Access Journals (Sweden)

    Nina J. Blumenstein

    2016-01-01

    Full Text Available In this study we investigated the influence of an organic polystyrene brush on the deposition of ZnO thin films under moderate conditions. On a non-modified SiOx surface, island growth is observed, whereas the polymer brush induces homogeneous film growth. A chemical modification of the polystyrene brushes during the mineralization process occurs, which enables stronger interaction between the then polar template and polar ZnO crystallites in solution. This may lead to oriented attachment of the crystallites so that the observed (002 texture arises. Characterization of the templates and the resulting ZnO films were performed with ζ-potential and contact angle measurements as well as scanning electron microscopy (SEM, atomic force microscopy (AFM and X-ray diffraction (XRD. Infrared spectroscopy (IR measurements were used to investigate the polystyrene brushes before and after modification.

  17. Silica-Polystyrene Nanocomposite Particles Synthesized by Nitroxide-Mediated Polymerization and Their Encapsulation through Miniemulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Bérangère Bailly

    2006-01-01

    Full Text Available Polystyrene (PS chains with molecular weights comprised between 8000 and 64000 g⋅mol-1 and narrow polydispersities were grown from the surface of silica nanoparticles (Aerosil A200 fumed silica and Stöber silica, resp. through nitroxide-mediated polymerization (NMP. Alkoxyamine initiators based on N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide (DEPN and carrying a terminal functional group have been synthesized in situ and grafted to the silica surface. The resulting grafted alkoxyamines have been employed to initiate the growth of polystyrene chains from the inorganic surface. The maximum grafting density of the surface-tethered PS chains was estimated and seemed to be limited by initiator confinement at the interface. Then, the PS-grafted Stöber silica nanoparticles were entrapped inside latex particles via miniemulsion polymerization. Transmission electron microscopy indicated the successful formation of silica-polystyrene core-shell particles.

  18. Nanopatterned polystyrene-b-poly(acrylic acid) surfaces to modulate cell-material interaction.

    Science.gov (United States)

    Lizundia, Erlantz; Sáenz-Pérez, Míriam; Patrocinio, David; Aurrekoetxea, Iskander; dM Vivanco, Maria; Vilas, José Luis

    2017-06-01

    In this work we explore the effect of surface nanoarchitecture of polystyrene (PS) and polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymer films on cell viability. PS and PS-b-PAA have been nanopatterned at temperatures of 110, 120 and 140°C using nanoporous aluminium oxide membranes (AAO) as a template. Surface architecture strongly depends on the infiltration temperature and the nature of the infiltrated polymer. High patterning temperatures yield hollow fibre shape architecture at the nanoscale level, which substantially modifies the surface hydrophobicity of the resulting materials. Up to date very scarce reports could be found in the literature dealing with the interaction of microstructured/nanostructured polymeric surfaces with cancer cells. Therefore, MCF-7 breast cancer cells have been selected as a model to conduct cell viability assays. The findings reveal that the fine-tuning of the surface nanoarchitecture contributes to the modification of its biocompatibility. Overall, this study highlights the potential of AAO membranes to obtain well-defined tailored morphologies at nanoscale level and its importance to develop novel soft functional surfaces to be used in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Capturing interdiffusion in polystyrene films using a coarse-grained model

    Science.gov (United States)

    Agrawal, Anupriya; Ge, Ting; Int Veld, Pieter J.; Perahia, Dvora; Grest, Gary S.

    Interdiffusion of polymers across interface underline self-healing processes and adhesion. Molecular simulations of interdiffusion must capture length scales comparable to the dimensions of the polymers and cover time scales up to the polymer diffusion times. This makes the use of coarse-grained models crucial. Here the interdiffusion of polystyrene films is simulated using a coarse-grained model. As the chain mobility in the coarse-grained model is intrinsically faster than that in the atomistic model, a dynamic scaling factor was first determined by comparing mobilities for short chains for the two models. The interpenetration of two polystyrene thin films were then followed for two films of equal molecular weight with N =500 and N =1760. Using this coarse-grained model, the temperature dependent interdiffusion was captured for time scale of hundreds of microseconds. The increases of mass uptake and interfacial width with time are faster for N =500 than for N =1760 and consistent with the predictions of reptation theory.

  20. Influence of metal frame on heat protection properties of a polystyrene concrete wall

    Directory of Open Access Journals (Sweden)

    Tsvetkov Nikolay

    2018-01-01

    Full Text Available The use of novel thermal-efficient building materials and technologies that allow increasing the level of thermal protection of external envelope structures and reducing the time for construction are of practical interest and represent a relevant task in the conditions of rapidly changing and increasing requirements to energy efficiency of buildings. This research aims at simulating the process of spatial heat transfer in a multilayer non-uniform structure of an external cast-in-place framed wall produced from polystyrene concrete with a stay-in-place formwork. Based on the physico-mathematical model developed with the use of ANSYS and COMSOL software complexes, parametric analysis of the impact of various factors on thermal behavior of the external wall was performed with the account of heat-stressed frame elements. The nature of temperature fields distribution in a polystyrene concrete structure was defined, and its thermal protection properties were investigated. The impact of a metal frame on thermal protection properties of a wall was found to be insignificant.

  1. Transmission of terahertz radiation by anisotropic MWCNT/polystyrene composite films

    Energy Technology Data Exchange (ETDEWEB)

    Okotrub, A.V.; Bulusheva, L.G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Ave., 630092 Novosibirsk (Russian Federation); Kubarev, V.V. [Budker Institute of Nuclear Physics, SB RAS, 11 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation); Kanygin, M.A.; Sedelnikova, O.V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation)

    2011-11-15

    Anisotropic composite materials have been prepared by repeated forge rolling of polystyrene and carbon nanotubes (CNTs) with length of {proportional_to}65 {mu}m. Transmission spectra of the composites were recorded for two different polarizations of the electric field. Obtained data indicated that the forge rolling resulted in a predominant orientation of CNTs in polymer matrix. Anisotropic response of the composites was measured at 130 {mu}m wavelength on the Novosibirsk terahertz free electron laser and angular dependence of the transmitted light was determined. Absorption spectrum showed no strong resonance features and it was interpreted by CNTs breaking and agglomeration of CNT fragments during the composite fabrication procedure. Based on classical theory of scattering, considered the scatters as electromagnetic antennas, the size distribution of CNTs in composites was found. Anisotropy of terahertz radiation transmitted from MWCNT/polystyrene composite film on the Novosibirsk free electron laser at 130 {mu}m wavelength. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Preparation of nano-CaCO3/polystyrene nanocomposite beads for efficient bilirubin removal.

    Science.gov (United States)

    Chen, Jian; Cheng, Guanghui; Chai, Yamin; Han, Wenyan; Zong, Wenhui; Chen, Jie; Li, Chunran; Wang, Weichao; Ou, Lailiang; Yu, Yaoting

    2018-01-01

    A novel nano-CaCO3/polystyrene nanocomposite adsorbent (NPS-8) was synthesized for efficient bilirubin removal from human plasma. A comparison with the polystyrene adsorbent (PS-8), which was without the incorporation of nano-CaCO3, revealed that NPS-8 had superior bilirubin adsorption capacity and mechanical strength. The resulting nano-CaCO3 reinforced PS-8 (NPS-8) was tested by transmission electron microscopy (TEM), scanning electron microscopy (SEM), mechanical strength test, and bilirubin adsorption assays. The adsorption results indicated that NPS-8 displayed better adsorption capacity for bilirubin (91%) than that of PS-8 (75.88%). The mechanical strength of NPS-8 was significantly greater than that of PS-8. In addition, both PS-8 and NPS-8 possessed good blood compatibility properties (a negligible hemolytic activity and platelet adhesion). Therefore, a conclusion could be drawn that NPS-8 has a high potential as an efficient bilirubin adsorbent for blood purification in clinical practice. At the same time, the success of organic-inorganic nanocomposite adsorbents might provide a new insight into the improvement of adsorbents in hemoperfusion. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Quantifying size-dependent interactions between fluorescently labeled polystyrene nanoparticles and mammalian cells

    Directory of Open Access Journals (Sweden)

    Varela Juan A

    2012-09-01

    Full Text Available Abstract Background Nanoparticles (NPs are currently used in a wide variety of fields such as technology, medicine and industry. Due to the novelty of these applications and to ensure their success, a precise characterization of the interactions between NPs and cells is essential. Findings The current study explores the uptake of polystyrene NPs by 1321N1 human astrocytoma and A549 human lung carcinoma cell lines. In this work we show for the first time a comparison of the uptake rates of fluorescently labeled carboxylated polystyrene (PS NPs of different sizes (20, 40 and 100 nm in two different cell types, keeping the number of NPs per unit volume constant for all sizes. We propose a reliable methodology to control the dose of fluorescently labeled NPs, by counting individual NPs using automated particle detection from 3D confocal microscopy images. The possibility of detecting individual NPs also allowed us to calculate the size of each nanoparticle and compare the fluorescence of single NPs across different sizes, thereby providing a robust platform for normalization of NP internalization experiments as measured by flow cytometry. Conclusions Our findings show that 40 nm NPs are internalized faster than 20 nm or 100 nm particles in both cell lines studied, suggesting that there is a privileged size gap in which the internalization of NPs is higher.

  4. Utility of expanded polystyrene (EPS) beads in the control of vector-borne diseases.

    Science.gov (United States)

    Sivagnaname, N; Amalraj, D Dominic; Mariappan, T

    2005-10-01

    The use of chemicals or bio-larvicides for the control of Culex quinquefasciatus and Anopheles stephensi breeding in pit latrines and overhead tanks (OHT) respectively is discouraged owing to many undesirable impacts in the environment. Due to faecal contamination and poor survival, use of predatory fish in OHTs is not feasible. The use of expanded polystyrene (EPS) beads is a potential alternative in these habitats. EPS beads not only prevent oviposition but also kill the immature by forming a thick blanket on the water surface. A thick layer of 2 cm with beads of 2 mm is sufficient to suppress and prevent mosquito breeding. These are cheap, environmentally safe and do not need frequent application since they remain on the surface for quiet a long time. Successful trials against C. quinquefasciatus breeding in pit latrines, soakage pits, septic tanks, etc., have been carried out in Kenya, Zimbabwe and Tanzania. Certain trials with EPS indicated reduction in microfilaria (mf) rate besides decline in biting density. In India, EPS beads have also been used on small scale for the control of A. stephensi and A. culicifacies breeding in OHTs and unused wells respectively. The polystyrene beads have also been reported to be effective in the control of mosquito breeding in biogas plants and other industrial situations. The practical utility of EPS beads in the control of vector-borne diseases has been discussed in the present review.

  5. Biodegradation characteristics of starch-polystyrene loose-fill foams in a composting medium.

    Science.gov (United States)

    Pushpadass, Heartwin A; Weber, Robert W; Dumais, Joseph J; Hanna, Milford A

    2010-10-01

    The structures and biodegradabilities of loose-fill foams, containing starch and polystyrene at ratios of 70:30 and 80:20, were evaluated using a laboratory composting system. Each formulation was foamed (extrusion expanded) using either 0.2% azodicarbonamide or 0.25% citric acid as the chemical blowing agent. Biodegradability, a measure of the quantity of material mineralized, was expressed as the percentage of CO(2) in the exhaust gas eluted from the individual chambers. The CO(2) generation peaked after about 15 days of composting, and then decreased. The rate and amount of CO(2) eluted depended on the starch content in the foams. Similarly, there were significant differences in the rates and quantities of CO(2) emissions for the foams blown with azodicarbonamide versus citric acid. At the end of the composting tests, the remaining foam material had fibrous and crumbly textures, presumably consisting primarily of polystyrene. FTIR and NMR spectra of the foams, taken after 39days of composting, did not reveal the spectral features of starch, thereby confirming the decomposition of the starch. Copyright 2010 Elsevier Ltd. All rights reserved.

  6. Study the adsorption of sulfates by high cross-linked polystyrene divinylbenzene anion-exchange resin

    Science.gov (United States)

    Fathy, Mahmoud; Moghny, Th. Abdel; Awadallah, Ahmed E.; El-Bellihi, Abdel-Hameed A.-A.

    2017-03-01

    In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

  7. Noise Removal with Maintained Spatial Resolution in Raman Images of Cells Exposed to Submicron Polystyrene Particles

    Directory of Open Access Journals (Sweden)

    Linnea Ahlinder

    2016-04-01

    Full Text Available The biodistribution of 300 nm polystyrene particles in A549 lung epithelial cells has been studied with confocal Raman spectroscopy. This is a label-free method in which particles and cells can be imaged without using dyes or fluorescent labels. The main drawback with Raman imaging is the comparatively low spatial resolution, which is aggravated in heterogeneous systems such as biological samples, which in addition often require long measurement times because of their weak Raman signal. Long measurement times may however induce laser-induced damage. In this study we use a super-resolution algorithm with Tikhonov regularization, intended to improve the image quality without demanding an increased number of collected pixels. Images of cells exposed to polystyrene particles have been acquired with two different step lengths, i.e., the distance between pixels, and compared to each other and to corresponding images treated with the super-resolution algorithm. It is shown that the resolution after application of super-resolution algorithms is not significantly improved compared to the theoretical limit for optical microscopy. However, to reduce noise and artefacts in the hyperspectral Raman images while maintaining the spatial resolution, we show that it is advantageous to use short mapping step lengths and super-resolution algorithms with appropriate regularization. The proposed methodology should be generally applicable for Raman imaging of biological samples and other photo-sensitive samples.

  8. Water wettability and zeta-potential of polystyrene surface modified by Ne or Na implantation

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Aiko; Suzuki, Yoshiaki; Iwaki, Masaya [Inst. of Physical and Chemical Research, Wako, Saitama (Japan). Div. of Surface Characterization

    1998-01-15

    A study has been made of the modification of the wettability and the surface potential of polystyrene by ion bombardment and implantation. Substrates used were polystyrene (PS) dishes. Ne bombardment and Na ion implantation were performed at energies of 50 and 150 keV with fluences between 1 {times} 10{sup 14} to 1 {times} 10{sup 17} ions/cm{sup 2}. The surface potential was examined by measurements of {zeta}-potential and the wettability was examined by the contact angle of water. The contact angle of water and the {zeta}-potential are found to change, depending on ion species and fluences. Two kinds of relationships between the contact angle of water and the {zeta}-potential are found, classified by region A and region B. From XPS results, region A means that PS surfaces modified by radiation effects of Ne-bombardment or Na-implantation have new functional groups and amorphous carbon. In region B, Na implanted PS surfaces with a high fluence show not only new functional groups and amorphous carbon but also Na atoms with chemical bonding states.

  9. Effect of Autoclaved Aerated Concrete Modification with High-Impact Polystyrene on Sound Insulation

    Science.gov (United States)

    Brelak, Sylwia; Dachowski, Ryszard

    2017-10-01

    Autoclaved aerated concrete is one of the most commonly used building materials. Its advantages include low density, high thermal insulation capacity and high fire resistance. It has a relatively high compressive strength, though not high enough to be able to compete with other building materials in this respect. One of the directions leading to the improvement of physical and mechanical properties of autoclaved aerated concrete is the modification of its composition. A noticeable effect of pulverized high-impact polystyrene (improved compressive strength and water absorption) was relevant for the decision to continue the study of its effects. This paper discusses the effect of high-impact polystyrene on sound insulation in AAC products. The tests demonstrated a positive influence of the modifier on AAC sound insulation enhancement. Results from the tests performed on HIPS-modified AAC products were showed and compared with the properties of conventional products. The effect of the polymer on the microstructure of the products obtained was described briefly.

  10. Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species.

    Science.gov (United States)

    Hadi, Yusuf Sudo; Massijaya, Muh Yusram; Arinana, A

    2016-07-21

    The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana), mangium (Acacia mangium), and pine (Pinus merkusii) were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance) to 10 (complete or near-complete resistance). Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples.

  11. Ripple polystyrene nano-pattern induced by KrF laser

    Directory of Open Access Journals (Sweden)

    P. Slepicka

    2014-07-01

    Full Text Available The study of excimer laser treatment of polystyrene surface was performed. The influence of laser fluence and number of laser pulses on surface chemistry and morphology was determined. The surface morphology and roughness were studied with atomic force microscopy. Surface wettability and aging studies were characterized by the water contact angle measurements. Surface oxygen concentration and chemistry were evaluated from X-ray photoelectron spectroscopy and zeta potential measurements. The optimal polystyrene treatment parameters for the most regular pattern were determined. The foils with optimal ripple pattern were subsequently sputtered with gold nano-layers of 100 nm thickness. It was found that the surface roughness of PS strongly depends on number of pulses. The aging study revealed that the higher contact angle achieve the samples treated with higher laser fluence. The deposition of gold nano-layer increases the surface roughness of nano-patterned surface. It was proved that the oxygen concentration is significantly influenced by the KrF laser exposure.

  12. Patterned Well-Aligned ZnO Nanorods Assisted with Polystyrene Monolayer by Oxygen Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Hyun Ji Choi

    2016-08-01

    Full Text Available Zinc oxide is known as a promising material for sensing devices due to its piezoelectric properties. In particular, the alignment of ZnO nanostructures into ordered nanoarrays is expected to improve the device sensitivity due to the large surface area which can be utilized to capture significant quantities of gas particles. However, ZnO nanorods are difficult to grow on the quartz substrate with well-ordered shape. So, we investigated nanostructures by adjusting the interval distance of the arranged ZnO nanorods using polystyrene (PS spheres of various sizes (800 nm, 1300 nm and 1600 nm. In addition, oxygen plasma treatment was used to specify the nucleation site of round, patterned ZnO nanorod growth. Therefore, ZnO nanorods were grown on a quartz substrate with a patterned polystyrene monolayer by the hydrothermal method after oxygen plasma treatment. The obtained ZnO nanostructures were characterized by X-ray diffraction (XRD and field-emission scanning electron microscope (FE-SEM.

  13. Microwave Irradiation Effect on the Dispersion and Thermal Stability of RGO Nanosheets within a Polystyrene Matrix

    Directory of Open Access Journals (Sweden)

    Edreese H. Alsharaeh

    2014-07-01

    Full Text Available Polystyrene-reduced graphene oxide (PSTY/RGO composites were prepared via the in situ bulk polymerization method using two different preparation techniques. The general approach is to use microwave irradiation (MWI to enhance the exfoliation and the dispersion of RGO nanosheets within the PSTY matrix. In the first approach, a mixture of GO and styrene monomers (STY were polymerized using a bulk polymerization method facilitated by microwave irradiation (MWI to obtain R-(GO-PSTY composites. In the second approach, a mixture of RGO and STY monomers were polymerized using a bulk polymerization method to obtain RGO-(PSTY composites. The two composites were characterized by FTIR, 1H-NMR, XRD, SEM, HRTEM, TGA and DSC. The results indicate that the composite obtained using the first approach, which involved MWI, had a better morphology and dispersion with enhanced thermal stability, compared with the composites prepared without MWI. Moreover, DSC results showed that the Tg value of the composites after loading the RGO significantly increased by 24.6 °C compared to the neat polystyrene.

  14. Production of Polystyrene Open-celled Microcellular Foam in Batch Process by Super Critical CO2

    Directory of Open Access Journals (Sweden)

    M.S. Enayati

    2010-12-01

    Full Text Available Open-celled foams are capable to allow the passage of fluids through their structure, because of interconnections between the open cells or bubbles and therefore these structures can be used as a membrane and filter. In thiswork, we have studied the production of polystyrene open-celled microcellular foam by using CO2 as blowing agent. To achieve such structures, it is necessary to control the stages of growth in such a way that the cells would connect to each other through the pores without any coalescence. The required processing condition to achieve open-celled structures is predictable by a model theory of opened-cell. This model suggests that at least a 130 bar saturation pressure and foaming time between 9 and 58 s are required for this system. The temperature range has been selected for to be both higher than polymer glass transition temperature and facilitating the foaming process. Experimental results in the batch foaming process has verified the model quite well. The SEM and mercury porousimetry tests show the presence of pores between the cells with open-celled structure. Experimental results show that by increasing the saturation pressure and the foaming temperature, there is a drop in the time required for open-celled structure formation. A 130 bar saturation pressure, 150o C foaming temperature and 60 s foaming time, suggest the attainment of open-celled microcellular foam based on polystyrene/CO2 system in the batch process.

  15. PHYSICAL AND MECHANICAL PROPERTIES OF THREE POLYSTYRENE IMPREGNATED INDONESIAN WOOD SPECIES

    Directory of Open Access Journals (Sweden)

    Nurwati Hadjib

    2005-07-01

    Full Text Available The disadvantage of  fast-growing species is  that they have inferior physical and mechanical properties. Polystyrene impregnation can be applied to improve physical and mechanical properties. Wood samples, which were dried  until 10% moisture content were put into impregnating tank and vacuum pressured  at 20-mm Hg  for  two hours. During  the gradual release of  vacuum, styrene monomers,  vinyl acetate  monomers  and  terburyl-peroxide catalyst was streamed  into  the tank. Afterwards, the pressure inside the tank was allowed to decrease to 500 mm Hg and kept for 60 minutes. Wood samples which had been impregnated were subsequently immersed in water, then wrapped in aluminum foils and put in the oven for 24 hours at 60°C. The samples were then tested for the polymer loading and their physical and mechanical properties. The results showed that the polymer loadings in wood plastics with the species  of origin (i.e. consecutively sengon, pine and rubber wood were 118%, 72% and 44%, respectively. Impregnation with polystyrene  (copolymer of styrene and vinyl acetate monomers could improve the physical and mechanical properties of wood plastics, i.e.  specific gravity, moisture content, water absorption,  shrinkage/ swelling, compression parallelto the wood grain, MOR and MOE. Greater  use of vinyl acetate decreased physical and mechanical properties.

  16. Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species

    Directory of Open Access Journals (Sweden)

    Yusuf Sudo Hadi

    2016-07-01

    Full Text Available The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana, mangium (Acacia mangium, and pine (Pinus merkusii were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance to 10 (complete or near-complete resistance. Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples.

  17. CO2 Induced Foaming Behavior of Polystyrene near the Glass Transition

    Directory of Open Access Journals (Sweden)

    Salah Al-Enezi

    2017-01-01

    Full Text Available This paper examines the effect of high-pressure carbon dioxide on the foaming process in polystyrene near the glass transition temperature and the foaming was studied using cylindrical high-pressure view cell with two optical windows. This technique has potential applications in the shape foaming of polymers at lower temperatures, dye impregnation, and the foaming of polystyrene. Three sets of experiments were carried out at operating temperatures of 50, 70, and 100°C, each over a range of pressures from 24 to 120 bar. Foaming was not observed when the polymer was initially at conditions below Tg but was observed above Tg. The nucleation appeared to occur randomly leading to subsequent bubble growth from these sites, with maximum radius of 0.02–0.83 mm. Three models were applied on the foaming experimental data. Variable diffusivity and viscosity model (Model C was applied to assess the experimental data with the WLF equation. The model shows very good agreement by using realistic parameter values. The expansion occurs by diffusion of a dissolved gas from the supersaturated polymer envelope into the bubble.

  18. Dynamic interactions of polystyrene particles with microstructured surface manufactured by cold spray

    Science.gov (United States)

    Krull, Fabian; Breuninger, Paul; Antonyuk, Sergiy

    2017-06-01

    Dynamic interactions of particles with component surfaces often occur during production, processing and transport of granular materials. The morphology of component surfaces has a significant effect on the impact behaviour of particles. The micro processes during an impact (e.g. rebound, rolling, sliding and sticking) can be changed by microstructuring of the surface. This paper deals with the estimation of the energy dissipation processes of polystyrene particles (400 - 700 μm) impacting on a stainless steel surface. The surface was structured with stainless steel particles (mean particle size 3.5 μm) via a cold spray process. Impact experiments were performed and restitution coefficient was measured. The proportion of the energy dissipation by impact on structured surface was 3.87-10.92 times higher than the dissipation on a polished surface. The additional energy absorption can be explained by multiple particle contacts with the steel asperities and additional friction due to the indentation of these asperities in the polystyrene particles. The particle size did not show any influence on the average energy absorption by collision on the microstructured surface. Only the coefficient of variation got higher, because of the inhomogeneous particle distribution.

  19. Dynamic interactions of polystyrene particles with microstructured surface manufactured by cold spray

    Directory of Open Access Journals (Sweden)

    Krull Fabian

    2017-01-01

    Full Text Available Dynamic interactions of particles with component surfaces often occur during production, processing and transport of granular materials. The morphology of component surfaces has a significant effect on the impact behaviour of particles. The micro processes during an impact (e.g. rebound, rolling, sliding and sticking can be changed by microstructuring of the surface. This paper deals with the estimation of the energy dissipation processes of polystyrene particles (400 – 700 μm impacting on a stainless steel surface. The surface was structured with stainless steel particles (mean particle size 3.5 μm via a cold spray process. Impact experiments were performed and restitution coefficient was measured. The proportion of the energy dissipation by impact on structured surface was 3.87–10.92 times higher than the dissipation on a polished surface. The additional energy absorption can be explained by multiple particle contacts with the steel asperities and additional friction due to the indentation of these asperities in the polystyrene particles. The particle size did not show any influence on the average energy absorption by collision on the microstructured surface. Only the coefficient of variation got higher, because of the inhomogeneous particle distribution.

  20. Properties of Polymer Electrolyte Membranes Prepared by Blending of Sulfonated Polystyrene-Lignosulfonate

    Directory of Open Access Journals (Sweden)

    Siang Tandi Gonggo

    2012-11-01

    Full Text Available Electrolyte polymer membrane widely used in PEMFC and DMFC is a perfluorosulfonated membrane such as Nafion. This membrane material exhibits good chemical stability and proton conductivity, but it is very expensive and difficult to recycle. It has high cross-over methanol in DMFC that causes the decrease efficiency and performance of fuel cell, so that the electrolyte polymer membrane with low cross-over methanol has been needed to substitute Nafion membrane. One of the materials used as a polymer electrolyte membrane is polyblends of a sulfonated polystyrene-lignosulfonate (SPS-LS. These polyblends have been prepared by casting polymer solution and characterized as a polyelectrolyte membrane for DMFC. SPS was prepared by sulfonation of polystyrene with acetyl sulfate used as a sulfonating agent. The membranes of SPS-LS were characterized by analysis of functional groups, mechanical properties, and methanol permeability. The maximum mechanical properties of the SPS-LS membrane were observed in LS ratio of 7.5%. However, the methanol permeability of membrane increases as the increase of LS ratio in SPS-LS membranes. The properties of membranes, especially the mechanical property and methanol permeability close to that of Nafion® 117 membrane, so the SPS-LS membrane is highly potential used as the electrolyte membrane for direct methanol fuel cell.

  1. An Electrically Conductive and Organic Solvent Vapors Detecting Composite Composed of an Entangled Network of Carbon Nanotubes Embedded in Polystyrene

    Directory of Open Access Journals (Sweden)

    R. Olejnik

    2012-01-01

    Full Text Available A composite composed of electrically conductive entangled carbon nanotubes embedded in a polystyrene base has been prepared by the innovative procedure, when the nonwoven polystyrene filter membrane is enmeshed with carbon nanotubes. Both constituents are then interlocked by compression molding. The mechanical and electrical resistance testing show that the polymer increases nanotube network mechanical integrity, tensile strength, and the reversibility of electrical resistance in deformation cycles. Another obvious effect of the supporting polymer is the reduction of resistance temperature dependence of composite and the reproducibility of methanol vapor sensing.

  2. Constant interchain pressure effect in extensional flows of oligomer diluted polystyrene and poly(methyl methacrylate) melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Huang, Qian

    2017-01-01

    The constant ‘interchain pressure’ idea has been addressed, to evaluate if it is an adequate quantitative assumption to describe the fluid mechanics of oligomer diluted entangled NMMD polymer systems. The molecular stress function constitutive framework has been used with the constant interchain ......)s and almost all published oligomer diluted NMMD polystyrenes. The only deviation is on the most diluted and largest molecular weight case of an 18% 1880 kg/mol polystyrene in oligomer diluent. In this case, the maximal extensibility is not needed....

  3. A polystyrene-based microfluidic device with three-dimensional interconnected microporous walls for perfusion cell culture

    Science.gov (United States)

    Chan, Chung Yu; Goral, Vasiliy N.; DeRosa, Michael E.; Huang, Tony Jun

    2014-01-01

    In this article, we present a simple, rapid prototyped polystyrene-based microfluidic device with three-dimensional (3D) interconnected microporous walls for long term perfusion cell culture. Patterned 3D interconnected microporous structures were created by a chemical treatment together with a protective mask and the native hydrophobic nature of the microporous structures were selectively made hydrophilic using oxygen plasma treatment together with a protective mask. Using this polystyrene-based cell culture microfluidic device, we successfully demonstrated the support of four days perfusion cell culture of hepatocytes (C3A cells). PMID:25379110

  4. Use of sodium polystyrene sulfonate in an acute-on-chronic lithium poisoned patient: A case report

    Directory of Open Access Journals (Sweden)

    Chakroun-Walha Olfa

    2016-03-01

    Full Text Available A 35-year-old woman with an acute-on-chronic lithium overdose received multiple oral doses of sodium polystyrene sulfonate totaling 120 g over a 24-h period. During the 72 h after the institution of therapy, the serum lithium level decreased from 3.80 to 0.42 mEq/L. Multiple doses of sodium polystyrene sulfonate may be useful in lowering the serum lithium level in severely ill patients with acute renal failure, and can substitute hemodialysis.

  5. One-pot synthesis of linear- and three-arm star-tetrablock quarterpolymers via sequential metal-free ring-opening polymerization using a "catalyst switch" strategy

    KAUST Repository

    Zhao, Junpeng

    2014-08-06

    A "catalyst switch" strategy has been used to sequentially polymerize four different heterocyclic monomers. In the first step, epoxides (1,2-butylene oxide and ethylene oxide) were successively polymerized from a monohydroxy or trihydroxy initiator in the presence of a strong phosphazene base promoter (t-BuP4). Then, an excess of diphenyl phosphate (DPP) was introduced, followed by addition and polymerization of a cyclic carbonate (trimethylene carbonate) and a cyclic ester (δ-valerolactone or ε-caprolactone). DPP acted as both neutralizer of the phosphazenium alkoxide (polyether chain end) and activator of the cyclic carbonate/ester. Using this method, linear- and star-tetrablock quarterpolymers were prepared in one pot. This work is emphasizing the strength of the previously developed catalyst switch strategy for the facile metal-free synthesis of complex macromolecular architectures. © 2014 Wiley Periodicals, Inc.

  6. Heparainization of gas plasma-modified polystyrene surfaces and the interactions of these surfaces with proteins studied with surface plasmon resonance

    NARCIS (Netherlands)

    van Delden, C.J.; van Delden, C.J.; Lens, J.P.; Lens, J.P.; Kooyman, R.P.H.; Engbers, G.H.M.; Feijen, Jan

    1997-01-01

    Polystyrene surfaces obtained by spin-coating a solution of polystyrene in toluene on a gold layer were functionalized with carboxylic acid groups by preadsorption of the sodium salt of undecylenic acid, followed by an argon plasma treatment. A conjugate of albumin and heparin (alb-hep) was

  7. The Influence of Green Surface Modification of Oil Palm Mesocarp Fiber by Superheated Steam on the Mechanical Properties and Dimensional Stability of Oil Palm Mesocarp Fiber/Poly(butylene succinate Biocomposite

    Directory of Open Access Journals (Sweden)

    Yoon Yee Then

    2014-08-01

    Full Text Available In this paper, superheated steam (SHS was used as cost effective and green processing technique to modify oil palm mesocarp fiber (OPMF for biocomposite applications. The purpose of this modification was to promote the adhesion between fiber and thermoplastic. The modification was carried out in a SHS oven at various temperature (200–230 °C and time (30–120 min under normal atmospheric pressure. The biocomposites from SHS-treated OPMFs and poly(butylene succinate (PBS at a weight ratio of 70:30 were prepared by melt blending technique. The mechanical properties and dimensional stability of the biocomposites were evaluated. This study showed that the SHS treatment increased the roughness of the fiber surface due to the removal of surface impurities and hemicellulose. The tensile, flexural and impact properties, as well as dimensional stability of the biocomposites were markedly enhanced by the presence of SHS-treated OPMF. Scanning electron microscopy analysis showed improvement of interfacial adhesion between PBS and SHS-treated OPMF. This work demonstrated that SHS could be used as an eco-friendly and sustainable processing method for modification of OPMF in biocomposite fabrication.

  8. Detection of Salmonella enterica serovar Enteritidis (SE) Antibodies in Serum Using A Polystyrene Bead/SE Flagella Agglutination Assay

    Science.gov (United States)

    Serologic screening of flocks can be an important method to detect Salmonella enteritidis (SE) infections but can be labor intensive or lack specificity. Our goal was to develop a rapid agglutination assay using SE flagella adsorbed to polystyrene beads as a simple, relatively specific test to dete...

  9. Low temperature growth of ZnO nanostructures on flexible polystyrene substrates for optical, photoluminescence and wettability applications

    Science.gov (United States)

    Durga Prasad, Muvva; Pasha Shaik, Ummar; Madhurima, V.; Ghanashyam Krishna, M.

    2016-08-01

    The growth of ZnO nanostructures on flexible polystyrene substrates by a simple vacuum thermal evaporation process is reported. The ZnO films are deposited on polystyrene surfaces of 6 μm thickness which are initially anchored on glass substrates. The as-deposited films are annealed at temperatures up to 180 °C for 6-24 h after which the polystyrene is lifted off from the glass substrates to yield nanostructured films on a flexible substrate. At 180 °C there is transformation of the partially oxidized as-deposited films into nearly stoichiometric ZnO. This is accompanied by the formation of nanostructures such as nanorods, nanotubes and nanodoughnuts. The films, which were 50-200 nm in thickness, are polycrystalline in nature and also exhibit Zn/ZnO core-shell structures under favorable conditions. The nanostructures exhibit transmission greater than 80% in the visible and near infrared regions and band gaps of the order of 4 eV. The films exhibit strong blue photoluminescence and the peak position as well as intensity of emission can be tuned by varying thickness and annealing conditions. To demonstrate the flexibility, the ZnO coated polystyrene substrates were wrapped around a LED to show UV blocking property. Wettability studies indicate that films are hydrophobic with water contact angles between 92°-95°.

  10. Role of nanoclay shape and surface characteristics on the morphology and thermal properties of polystyrene nanocomposites synthesized via emulsion polymerization

    CSIR Research Space (South Africa)

    Greesh, N

    2013-10-01

    Full Text Available This work evaluates the role of the surface properties and shape of clay type on the morphology, thermal, and thermo-mechanical properties of the polystyrene (PS)/clay nanocomposites prepared via free-radical emulsion polymerization. Attapulgite...

  11. The elution of metal cyanocomplexes from polyacrylic - and polystyrene- based ion exchange resins using nitrate and thiocyanate eluants

    Directory of Open Access Journals (Sweden)

    J. C. Riani

    2007-09-01

    Full Text Available Ion exchange resins can potentially be applied in cyanide recycling to address growing environmental concerns over the use of cyanide during gold extraction. In the present work the elution of copper-, iron-, and zinc-cyanocomplexes from polyacrylic- and polystyrene-based resins was studied. It was found that iron and copper cyanides are easily eluted from polyacrylic- and polystyrene-based ion exchange resins using either SCN- or NO3-. However, elution of the zinc cyanide complex from polystyrene-based resins was poor when using nitrate solution as eluant. Besides, an increase in elution temperature from 25 °C to 50 °C improved the elution of iron and zinc cyanides from polystyrene-based resins using a nitrate eluant; however temperature did not have any significant effect on other metal cyanocomplexes or for elution using thiocyanate. It was therefore proposed that the optimal combination of resin-eluant was site-specific, and depends on the features of the effluent, processing temperature, eluant concentration, and ion exchange resin under consideration.

  12. Effect of Organic Co-blowing Agents on the Morphology of CO2 Blown Microcellular Polystyrene Foams.

    Czech Academy of Sciences Publication Activity Database

    Nistor, A.; Topiař, Martin; Sovová, Helena; Kosek, J.

    2017-01-01

    Roč. 130, DEC 2017 (2017), s. 30-39 ISSN 0896-8446 R&D Projects: GA ČR(CZ) GA14-18938S Institutional support: RVO:67985858 Keywords : polystyrene * closed-cell microcellular foam * co-blowing agent Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.991, year: 2016

  13. Development of polystyrene calorimeter for application at electron energies down to 1.5 MeV

    DEFF Research Database (Denmark)

    Miller, A.; Kovacs, A.; Kuntz, F.

    2002-01-01

    Polystyrene (PS) calorimeters developed at Riso National Laboratory for use below 4 MeV have been modified due to irradiation technology requirements concerning both design principles and dimensions. The temperature-time relationship after irradiation was measured, and two ways of dose measurement...

  14. Reactive blending of poly(styrene-maleic) anhydride with poly(phenylene oxide) by addition of `-amino-polystyrene

    NARCIS (Netherlands)

    Koning, Cor; Ikker, Andreas; Ikker, A.; Borggreve, Rein; Leemans, Luc; Möller, Martin; Moller, M.

    1993-01-01

    -(3-Aminopropyl-l-amino)polystyrene (-amino-PS) was melt-blended with styrene/maleic anhydride copolymers (SMA) containing 28 wt% maleic anhydride groups. The terminal primary amino group can react with the maleic anhydride monomer units in SMA, forming imides. The resulting product turned out to be

  15. Quantification of biofilm production on polystyrene by Listeria, Escherichia coli and Staphylococcus aureus isolated from a poultry slaughterhouse

    Directory of Open Access Journals (Sweden)

    Laura Beatriz Rodrigues

    2010-12-01

    Full Text Available This study assessed biofilm formation on polystyrene by Staphylococcus aureus, Listeria monocytogenes, L. welshimeri and Escherichia coli, isolated from a slaughtering plant, grown on tryptic soy broth (TSB using different glucose concentrations. The tested bacteria produced biofilm in at least one of the concentrations used, and some of them were strong biofilm producers.

  16. Size-Dependent Regulation of Intracellular Trafficking of Polystyrene Nanoparticle-Based Drug-Delivery Systems.

    Science.gov (United States)

    Wang, Ting; Wang, Lu; Li, Xiaoming; Hu, Xingjie; Han, Yuping; Luo, Yao; Wang, Zejun; Li, Qian; Aldalbahi, Ali; Wang, Lihua; Song, Shiping; Fan, Chunhai; Zhao, Yun; Wang, Maolin; Chen, Nan

    2017-06-07

    Nanoparticles (NPs) have shown great promise as intracellular imaging probes or nanocarriers and are increasingly being used in biomedical applications. A detailed understanding of how NPs get "in and out" of cells is important for developing new nanomaterials with improved selectivity and less cytotoxicity. Both physical and chemical characteristics have been proven to regulate the cellular uptake of NPs. However, the exocytosis process and its regulation are less explored. Herein, we investigated the size-regulated endocytosis and exocytosis of carboxylated polystyrene (PS) NPs. PS NPs with a smaller size were endocytosed mainly through the clathrin-dependent pathway, whereas PS NPs with a larger size preferred caveolae-mediated endocytosis. Furthermore, our results revealed exocytosis of larger PS NPs and tracked the dynamic process at the single-particle level. These results indicate that particle size is a key factor for the regulation of intracellular trafficking of NPs and provide new insight into the development of more effective cellular nanocarriers.

  17. Role of Entropic Barriers in Controlling Polymer Diffusion in Polystyrene Nanocomposites

    Science.gov (United States)

    Griffin, Philip; Tung, Wei-Shao; Meth, Jeffrey; Clarke, Nigel; Composto, Russell; Winey, Karen

    Polymer diffusion in polymer nanocomposites (PNCs) is significantly modified relative to the neat state. While it is suspected that nanoparticle-induced confinement plays a key role in the diffusion process, a detailed understanding of this process remains nonetheless elusive. We present recent studies of the temperature dependent polymer center-of-mass tracer diffusion coefficient in an athermal PNC comprising polystyrene and phenyl-capped, spherical silica NPs using elastic recoil detection. We find that the polymer tracer diffusion coefficient in the PNC relative to the bulk decreases with increasing nanoparticle concentration and is unexpectedly more strongly reduced at higher temperatures. This unusual temperature dependence of polymer diffusion in PNCs cannot be explained by the reptation model or a modified version incorporating an effective tube diameter, but instead it is the direct result of entropic free energy barriers imposed on polymer chains under confinement.

  18. Capillary-force-induced formation of luminescent polystyrene/(rare-earth-doped nanoparticle) hybrid hollow spheres.

    Science.gov (United States)

    Chen, Min; Xie, Lin; Li, Fuyou; Zhou, Shuxue; Wu, Limin

    2010-10-01

    This paper presents a "one-pot" procedure to synthesize polystyrene/(rare-earth-doped nanoparticles) (PS/REDNPs) hybrid hollow spheres via the in situ diffusion of organic core into inorganic shell under strong capillary force. In this approach, when carboxyl-capped PS colloids were deposited by different REDNPs in aqueous medium, such as LaF3:Eu3+, LaF3:Ce3+-Tb3+, and YVO4:Dy3+, PS/REDNPs inorganic-organic hybrid hollow spheres could be directly obtained via the in situ diffusion of core PS chains into the voids between rare-earth-doped nanoparticles through the strong capillary force. Not only is the synthetic procedure versatile and very simple, but also the obtained hybrid hollow spheres are hydrophilic and luminescent and could be directly used in chemical and biological fields.

  19. Preparation and study of polystyrene/organic montmorillonite nanocomposite as lubricant additive of drilling fluid

    Science.gov (United States)

    Yu, Chengcheng; Ke, Yangchuan

    2017-08-01

    In this article, polystyrene/organic montmorillonite (PS/OMMT) nanocomposite was prepared via in-situ emulsion polymerization of styrene in the presence of organic montmorillonite. The certain amount of PS/OMMT nanocomposite and silicone oil mixtures provided novel nanocomposite lubricant additives of drilling fluid. Their experiment evaluations showed that the nanocomposite lubricant drilling fluid had the temperature resistance to increase up to 200°C, high lubricant with base drilling fluid compatibility, and stable rheological property. At 1.0 wt.% nanocomposite lubricant load in the base drilling fluid, the lubrication coefficient reduction rate reached 85.0%, the foaming rate was so low to 0.53%˜1.56%, and the filtration loss was decreased. This provided multifunctional practical nanocomposite lubricants and working fluids.

  20. Influence of fall height on high impact polystyrene deformation and characteristics of drop weight test

    Directory of Open Access Journals (Sweden)

    Mizera Ales

    2017-01-01

    Full Text Available This study deals with high impact polystyrene (HIPS which was subjected the drop-weight test. HIPS is a polymer produced by the reaction between butadiene synthetic elastomer and styrene (5–14 % which contains the crystal polymer in certain amounts and is commonly used in mechanical engineering applications where machine parts are exposed to impact loading. The injection moulded HIPS samples were subjected the penetration test at different fall heights and the results were subsequently evaluated and discussed. It was found out that all fall heights are suitable for HIPS penetration, but the optimal one is 50 J because of the smallest variation range. Higher heights are not needed because of increasing power consumption of the test device. From the results, it is clear, that HIPS is not so highly impact resistant material as for example HDPE, because of that is this material suitable for applications where is not often exposed to too big impacts at high velocities.

  1. X-ray Spectromicroscopy Study of Protein Adsorption to a Polystyrene-Polylactide Blend

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Bonnie; Hitchcock, Adam; Cornelius, Rena; Brash, John; Scholl, Andreas; Doran, Andrew

    2010-06-09

    Synchrotron-based X-ray photoemission electron microscopy (X-PEEM) was used to study the adsorption of human serum albumin (HSA) to polystyrene-polylactide (40:60 PS-PLA, 0.7 wt percent) thin films, annealed under various conditions. The rugosity of the substrate varied from 35 to 90 nm, depending on the annealing conditions. However, the characteristics of the protein adsorption (amounts and phase preference) were not affected by the changes in topography. The adsorption was also not changed by the phase inversion which occured when the PS-PLA substrate was annealed above Tg of the PLA. The amount of protein adsorbed depended on whether adsorption took place from distilled water or phosphate buffered saline solution. These differences are interpreted as a result of ionic strength induced changes in the protein conformation in solution.

  2. Interactions between halloysite nanotubes and poly(styrene sulfonate) in solution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Heon; Ryu, Jung Ju; Shin, Joo Huei; Lee, Hoik; Sohn, Dae Won [Dept. of Chemistry and Research Institute for Convergence of Basic Science, Hanyang University, Seoul (Korea, Republic of); Kim, Ick Soo [Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, Nagano (Japan)

    2017-01-15

    The interaction between halloysite nanotubes (HNT) and poly(styrene sulfonate) (PSS) in aqueous solution was investigated by dynamic light scattering. Dynamic behavior of HNT/PSS was observed with different salt, HNT, and PSS concentrations. The HNT colloids were stabilized by PSS over a wide range of HNT concentrations, and HNT suspension in dilute solution formed stable HNT/PSS particles. On the other hand, HNT particles aggregated as sediments at higher concentrations due to strong attraction among HNT rods, and HNT aggregates were stabilized by additional PSS. The interactions between HNT and PSS are described by the van der Waals–London force (VDWL). The stabilization process of HNT/PSS particles in salt solution was proposed by comparing the hydrodynamic radii and apparent intensities of samples. The results demonstrate that electrostatic, steric, and depletion stabilization processes are responsible for the stable dispersion of HNT even at high concentration.

  3. Time and Temperature Dependence of CdS Nanoparticles Grown in a Polystyrene Matrix

    Directory of Open Access Journals (Sweden)

    F. Antolini

    2012-01-01

    Full Text Available Luminescent CdS nanocrystals embedded in a polystyrene matrix were successfully prepared. The in situ growth of CdS QDs was realized by thermal treatment of Cd bis(thiolate/polymer foil at different times and temperatures (240°C and 300°C of annealing, in order to evaluate their influence on the quantum dots growth process. As a general trend, the increasing of time and temperature of annealing induces a rise of the CdS nanocrystals size into the polymeric matrix. The size distribution, morphology, and structure of the CdS nanoparticles were analysed with HRTEM and XRD experiments. UV-Vis and PL data are strongly size-dependent and were used to investigate the particles' growth process, too. The CdS nanoparticles behavior in solution indicated a general trend of QDs to aggregation. This predisposition was clearly displayed by DLS measurements.

  4. Thickness effect on electric resistivity on polystyrene and carbon black- based composites

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Lopez, S; Vigueras-Santiago, E [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA) Facultad de Quimica, Paseo Colon Esquina con Paseo Tollocan, s/n, CP 50000, Toluca (Mexico); Mayorga-Rojas, M; Reyes-Contreras, D, E-mail: eviguerass@uaemex.m [Facultad de Ciencias, Universidad Autonoma del Estado de Mexico. Av. Instituto Literario 100 Ote. C. P. 50000, Toluca (Mexico)

    2009-05-01

    Changes on electrical resistivity were experimentally studied for polystyrene and carbon black-based composites respect to the temperature. 22% w/w carbon black composite films at 30{mu}m, 2mm y 1cm thick were submitted to thermal heating-cooling cycles from room temperature to 100 deg. C, slightly up to T{sub g} of the composite. For each cycle changes on electrical resistivity constituent a hysteresis loop that depends on the sample thickness. The changes during the heating stage could be explained as a consequence of the thermal expansion and mobility of the polymer chains at T{sub g}, producing a disconnecting of the electrical contacts among carbon black particles and an important increasing (200%) of the electrical resistivity. For each cycle, the hysteresis loop was observed in thicker samples, whereas for 30 mu m thickness sample the hysteresis loop was lost after four cycles.

  5. The transition between undiluted and oligomer-diluted states of nearly monodisperse polystyrenes in extensional flow

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik K.

    2017-01-01

    We have measured the startup and steady extensional viscosity of two narrow molar mass distributed (NMMD) polystyrenes, a 910 kg/mole and a 545 kg/mole, diluted in a NMMD 4.29 kg/mole styrene oligomer, with a wide concentration range from 90 down to 17%. The constant interchain pressure model......, proposed by Rasmussen and Huang (Rheol Acta 53(3):199–208 (2014a)), predicts the extensional viscosity well for the dilutions with lower concentrations. However, for the 70 and 90% 545 kg/mole samples which represent the transition between the diluted and undiluted states, the model predictions are less...... satisfactory. Another concept based on interchain pressure, proposed by Wagner (Rheol Acta 53(10):765–777 (2014)), also shows agreement with the measured data....

  6. Pulsed-field capillary electrophoresis: optimizing separation parameters with model mixtures of sulfonated polystyrenes.

    Science.gov (United States)

    Sudor, J; Novotny, M V

    1994-07-01

    The electrophoretic transport of high molecular weight charged solutes, both flexible and stiff polymers, has been studied by capillary electrophoresis under constant-field and pulsed-field conditions. Sulfonated polystyrenes were used as model solutes in different entangled polymer solutions. First, changes of the end-to-end distance vectors of flexible polymers were examined through the mobility/potential-gradient curves. Under pulsed-field conditions, the influence of different pulse shapes, frequencies, and amplitudes of forward and backward pulses on the electrophoretic mobilities of model solutes was studied. Resolution of the mixture components was strongly affected by changes in frequency of both sine-wave and square-wave pulses. The experimental results obtained under pulse-field conditions are roughly in agreement with the existing theories of electrophoretic transport.

  7. Conductive nanocomposites based on polystyrene microspheres and silver nanowires by latex blending.

    Science.gov (United States)

    Sureshkumar, Manthiriyappan; Na, Hyo Yeol; Ahn, Kyung Hyun; Lee, Seong Jae

    2015-01-14

    Metallic nanowires with excellent electrical conductivity and high aspect ratio are critical in the preparation of conductive polymer nanocomposites. In this work, highly conductive polystyrene/silver nanowire (PS/AgNW) nanocomposites were prepared by latex blending, and their electrical and rheological properties were investigated. A high yield of long and thin AgNWs was synthesized with the polyol method. AgNWs were incorporated with highly monodisperse PS microspheres to produce polymer nanocomposites with a nanowire network structure providing electrical pathways. An electrically conductive network of AgNWs was obtained at an electrical percolation threshold of 0.49 vol % AgNW, and an electrical conductivity of 10(2) S/m was obtained at 1 vol %. The dynamic rheological properties evaluated at 1 vol % also confirmed that the AgNWs were physically connected to one another at this concentration.

  8. A small scale field trial with expanded polystyrene beads for mosquito control in septic tanks.

    Science.gov (United States)

    Chang, M S; Lian, S; Jute, N

    1995-01-01

    A field trial of the use of expanded polystyrene beads (EPSB) to control the breeding of mosquito larvae in household septic tanks was conducted in Sarawak. One week after treatment, the breeding of Culex quinquefasciatus and Aedes albopictus was reduced by 100% and 68.7% respectively. For both species combined, a 57.25% reduction in the adult emergence rate was achieved. No adult was caught in the emergence trap one month after treatment. A reduction in mosquito biting rates was reported by 87.3% of respondents. All households regarded the EPSB treatment as effective. This study has reduced the relatively high infestation rate of A. albopictus in the septic tanks to 16-20%. The EPSB treatment is feasible and practical. Post-treatment assessment using adult emergence traps and the implications for the vector control programme of the local authority are discussed.

  9. Modeling Large Deformation and Failure of Expanded Polystyrene Crushable Foam Using LS-DYNA

    Directory of Open Access Journals (Sweden)

    Qasim H. Shah

    2014-01-01

    Full Text Available In the initial phase of the research work, quasistatic compression tests were conducted on the expanded polystyrene (EPS crushable foam for material characterisation at low strain rates (8.3×10-3~8.3×10-2 s−1 to obtain the stress strain curves. The resulting stress strain curves are compared well with the ones found in the literature. Numerical analysis of compression tests was carried out to validate them against experimental results. Additionally gravity-driven drop tests were carried out using a long rod projectile with semispherical end that penetrated into the EPS foam block. Long rod projectile drop tests were simulated in LS-DYNA by using suggested parameter enhancements that were able to compute the material damage and failure response precisely. The material parameters adjustment for successful modelling has been reported.

  10. Cationic Biomimetic Particles of Polystyrene/Cationic Bilayer/Gramicidin for Optimal Bactericidal Activity

    Directory of Open Access Journals (Sweden)

    Gabriel R. S. Xavier

    2017-12-01

    Full Text Available Nanostructured particles of polystyrene sulfate (PSS covered by a cationic lipid bilayer of dioctadecyldimethylammonium bromide (DODAB incorporated gramicidin D (Gr yielding optimal and broadened bactericidal activity against both Escherichia coli and Staphylococcus aureus. The adsorption of DODAB/Gr bilayer onto PSS nanoparticles (NPs increased the zeta-average diameter by 8–10 nm, changed the zeta-potential of the NPs from negative to positive, and yielded a narrow size distributions for the PSS/DODAB/Gr NPs, which displayed broad and maximal microbicidal activity at very small concentrations of the antimicrobials, namely, 0.057 and 0.0057 mM DODAB and Gr, respectively. The results emphasized the advantages of highly-organized, nanostructured, and cationic particles to achieve hybrid combinations of antimicrobials with broad spectrum activity at considerably reduced DODAB and Gr concentrations.

  11. Physical and Morphological Properties for Foams of Polystyrene/SBR Blends

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Yong Bong; Noh, Si Tae [Department of Chemical Engineering, Hanyang University, Ansan (Korea); Hwang, Seok Ho; Lee, Youngchul [Chemical and Bio Technology Team, Korea Institute of Industrial Technology, Chonan (Korea)

    2001-02-01

    In this study, blends of polystyrene(PS) and Styrene-Butadiene-Rubber(SBR) were prepared by mixing in the kneader, and then the foams of blends were prepared by extruding with a foaming agent in a single screw exturder. We investigated the physical properties and morphological behaviors of blended foams by UTM, SEM and Densitmeter. The number of cells in the foamed PS/SBR blends matrix increased as the processing temperature decreased. Also, the structure of cell changed from closed cell structure to open cell structure as SBR fraction increased. In PS/SBR blends, the impact strength was improved by adding SBR, however, the flexural strength was decreased except for the 5 wt% SBR. 9 refs., 7 figs., 1 tabs.

  12. Vapor deposition of polystyrene thin films by intense laser vibrational excitation

    DEFF Research Database (Denmark)

    Bubb, D.M.; Papantonakis, M.R.; Horwitz, J.S.

    2002-01-01

    -induced damage to the target can be seen. RIR-PLD is a fundamentally new approach to polymer thin film growth as the absorption of radiation resonant with vibrational modes allow the energy to be deposited into the polymer and transfers between macromolecules in such a way as to promote efficient, non......Polystyrene films were deposited using resonant infrared pulsed laser depositions (RIR-PLD). Thin films were grown on Si(1 1 1) wafers and NaCl substrates and analyzed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The depositions were carried out...... in vacuum (10(-4)-10(-5) Torr) at wavelengths 3.28, 3.30, 3.42 and 3.48 mum which are resonant with CH2 stretching modes in the polymer. We also attempted to deposit a films using non-resonant infrared (RIR) excitation (2.90 mum). At this wavelength no films were deposited, and evidence for laser...

  13. Fluorescent QDs-polystyrene composite nanospheres for highly efficient and rapid protein antigen detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Changhua; Mao, Mao [Henan University, Key Laboratory for Special Functional Materials of the Ministry of Education (China); Yuan, Hang [Tsinghua University, Life Science Division, Graduate School at Shenzhen (China); Shen, Huaibin [Henan University, Key Laboratory for Special Functional Materials of the Ministry of Education (China); Wu, Feng; Ma, Lan, E-mail: malan@sz.tsinghua.edu.cn [Tsinghua University, Life Science Division, Graduate School at Shenzhen (China); Li, Lin Song, E-mail: lsli@henu.edu.cn [Henan University, Key Laboratory for Special Functional Materials of the Ministry of Education (China)

    2013-09-15

    In this paper, high-quality carboxyl-functionalized fluorescent (red, green, and blue emitting) nanospheres (46-103 nm) consisting of hydrophobic quantum dots (QDs) and polystyrene were prepared by a miniemulsion polymerization approach. This miniemulsion polymerization approach induced a homogeneous distribution and high aqueous-phase transport efficiency of fluorescent QDs in composite nanospheres, which proved the success of our encoding QDs strategy. The obtained fluorescent nanospheres exhibited high stability in aqueous solution under a wide range of pH, different salt concentrations, PBS buffer, and thermal treatment at 80 Degree-Sign C. Based on the red emitting composite nanosphere, we performed fluorescent lateral flow immunoassay (LFIA) strips for high-sensitivity and rapid alpha-fetal protein detection. The detection limit reached 0.1 ng/mL, which was 200 times higher than commercial colloidal gold-labeled LFIA strips, and it reached similar detection level in enzyme-linked immunosorbent assay kit.

  14. Fluorescent QDs-polystyrene composite nanospheres for highly efficient and rapid protein antigen detection

    Science.gov (United States)

    Zhou, Changhua; Mao, Mao; Yuan, Hang; Shen, Huaibin; Wu, Feng; Ma, Lan; Li, Lin Song

    2013-09-01

    In this paper, high-quality carboxyl-functionalized fluorescent (red, green, and blue emitting) nanospheres (46-103 nm) consisting of hydrophobic quantum dots (QDs) and polystyrene were prepared by a miniemulsion polymerization approach. This miniemulsion polymerization approach induced a homogeneous distribution and high aqueous-phase transport efficiency of fluorescent QDs in composite nanospheres, which proved the success of our encoding QDs strategy. The obtained fluorescent nanospheres exhibited high stability in aqueous solution under a wide range of pH, different salt concentrations, PBS buffer, and thermal treatment at 80 °C. Based on the red emitting composite nanosphere, we performed fluorescent lateral flow immunoassay (LFIA) strips for high-sensitivity and rapid alpha-fetal protein detection. The detection limit reached 0.1 ng/mL, which was 200 times higher than commercial colloidal gold-labeled LFIA strips, and it reached similar detection level in enzyme-linked immunosorbent assay kit.

  15. Optical Characteristics of Polystyrene Based Solid Polymer Composites: Effect of Metallic Copper Powder

    Directory of Open Access Journals (Sweden)

    Shujahadeen B. Aziz

    2013-01-01

    Full Text Available Solid polymer composites (SPCs were prepared by solution cast technique. The optical properties of polystyrene doped with copper powder were performed by means of UV-Vis technique. The optical constants were calculated by using UV-Vis spectroscopy. The dispersion regions were observed in both absorption and refractive index spectra at lower wavelength. However, a plateau can be observed at high wavelengths. The small extinction coefficient compared to the refractive index reveals the transparency of the composite samples. The refractive index and optical band gap were determined from the reflectance and optical absorption coefficient data, respectively. The nature of electronic transition from valence band to conduction band was determined and the energy band gaps of the solid composite samples were estimated. It was observed that, upon the addition of Cu concentration, the refractive index increased while the energy gaps are decreased. The calculated refractive indexes (low index of refraction of the samples reveal their availability in waveguide technology.

  16. Influences of Thermal Treatment on the Dielectric Performances of Polystyrene Composites Reinforced by Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Benhui Fan

    2017-07-01

    Full Text Available Dielectric properties of composites near percolation threshold (fc are often sensitive to thermal treatments, and the annealing temperature is usually associated with a polymer’s rheological properties. In this study, the influences of the thermal treatment on dielectric properties are investigated for the polystyrene (PS matrix composite reinforced by graphene nanoplatelets (GNP fillers near fc. It can be found that the thermal treatment can not only increase the dielectric constant, but also decrease the dielectric loss for the PS/GNP composite. This interesting phenomenon possibly happens in the interfacial region of PS/GNP with the thickness about 4–6 nm according to the electron energy-loss spectroscopy (EELS results. The free volumes around the interface can be easily altered by the movement of polymeric segments after annealing at the glass transition temperature.

  17. Effects of polystyrene microplastics on the fitness of earthworms in an agricultural soil

    Science.gov (United States)

    Cao, Dongdong; Wang, Xiao; Luo, Xianxiang; Liu, Guocheng; Zheng, Hao

    2017-04-01

    Microplastics (MPs) pollution is widespread in the environment, while the effects of MPs on the soil organisms are poorly understood. In this study, we investigated the fitness of earthworms (E. Foetida) exposed to MPs (Polystyrene, 58 μm) in soils at the concentrations of 0, 0.25, 0.5, 1 and 2% (w/w). The results showed that MPs had little effects on the fitness of earthworms under low exposure concentrations (≤ 0.5 % (w/w)), while MPs exposure with high concentrations (i.e., 1% and 2%) significantly inhibited the growth and increased the mortality of earthworms. The results indicated that the MPs pollution in soils have an adverse effect on the fitness of soil organisms, and implied the ecological risk of MPs in terrestrial ecosystems.

  18. Phase continuity and inversion in polystyrene/poly(methyl methacrylate) blends

    DEFF Research Database (Denmark)

    Chuai, Chengzhi; Almdal, K.; Lyngaae-Jørgensen, Jørgen

    2003-01-01

    Dual-phase continuity and phase inversion of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends processed in a twin-screw extruder was investigated using a selective extraction technique and scanning electron microscopy. Emphasis was placed on investigating the effects of viscosity ratio......, blend composition, processing variables (mixing time and annealing) and diblock copolymer addition on the formation of bi-continuous phase structure (BPS) in PS/PMMA blends. The experimental results were compared with the volume fraction of phase inversion calculated with various semi-empirical models...... of volume fraction in which BPS exists. Quiescent annealing coarsened the structure but indicated no qualitative changes. Some model predictions for phase inversion could predict qualitative aspects of the observed windows of co-continuity but none of the models could account quantitatively for the observed...

  19. AlGaInP Red LEDs with Hollow Hemispherical Polystyrene Arrays.

    Science.gov (United States)

    Cheng, Wen-Ching; Huang, Shih-Yung; Chen, Yi-Jiun; Wang, Chia-Sheng; Lin, Hoang Yan; Wu, Tzong-Ming; Horng, Ray-Hua

    2018-01-17

    A hollow hemispherical polystyrene (HHPS) was fabricated to reduce total internal reflection in AlGaInP-based LEDs. At an injection current of 350 mA, the external quantum efficiencies of LED-I, LED-II, LED-III, and LED-IV are 20.92%, 24.65%, 27.28%, and 33.77% and the wall-plug efficiencies are 17.11%, 20%, 22.5%, and 27.33%, respectively. The enhanced performance is attributed to the light output power enhancement through the surface roughness, microlens-liked PS hemisphere, and scatter-liked HHPS array. In this paper, the rigorous coupled wave analysis (RCWA) numerical method was also conducted to demonstrate the HHPS array effectively enlarge the effective light cone.

  20. Filtration capacity on rapid filters and adsorption characteristics of polystyrene granules.

    Science.gov (United States)

    Schöntag, Juliana M; Moreira, Filipe M; Sens, Maurício L

    2017-08-01

    Polystyrene (PS) beads have been studied as a possible filter element, with the aim of increasing the effective production of water in treatment plants. Being a granular material of an effective size of 0.68 mm, sphericity of 0.96 and density of 1046 kg/m3, the use of PS beads may provide washing water savings because they require low velocities for expansion during backwash. However, other aspects must be considered before the adoption of this material, such as the filtration mechanisms associated with it. Analyses of turbidity retention and head loss variation throughout the filter run were observed, and acceptable filtration rates were achieved (pilot tests). There was bit adhesion of particulates on bead surfaces, which was observed by scanning electron microscopy. The beads showed a low adsorption capacity, which was assessed using methylene blue (lab tests).