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Sample records for polystyrene estabilizacao radiolitica

  1. Radiolytic stabilization of poly(methyl methacrylate) in blends with polystyrene; Estabilizacao radiolitica do poli(metacrilato de metila) em misturas fisicas com poliestireno

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Ivania Soares de

    2002-04-01

    In this work the radiolytic stabilization of poly(methyl methacrylate) was analyzed by three radioprotective agents: polystyrene (PS) and hindered amine light stabilizers (HEALS), respectively, PMMA/PS systems, so a called polymeric blends were prepared with different compositions, where the miscibility of these blends were studied using viscometric, microscopy (SEM) and spectroscopy (FT-IR) techniques. The results show that PMMA/PS blends in the compositions below 10 wt% of PS are miscible, on films casting from solution of toluene and methyl-ethyl-ketone (1;1) mixture. On the other hand, in the composition above 10 wt% of PS, PMMA/PS blends show imminiscibility behavior. These polymer solutions were irradiated with gamma rays ({sup 60} Co) and viscometric, microscopic and spectroscopic experiments show gamma radiation-induced compatibilization on PMMA/PS blends on proportion 50/50 and 30/70 take place. Viscometric interaction parameters of miscible and compatibilized PMMA/PS bends were calculated in the range of - 50 kGy, with the goal to find out the polymeric interactions after irradiation of the films. G values of PMMA, PMMA/PS and PMMA+St systems were calculated in order to analyze the radioprotection of PS and St into PMMA matrix. The results show that (90/10) PMMA/PS and PMMA+1,5%St systems promote protection against the gamma the radiation-induced scissions, effect that leads to polymer degradation. Moreover, a small amount of crosslinking observed in irradiated blends has contributed to stabilize mechanical properties of PMMA films. PMMA+0,3% HALS system irradiated in doses above 60 kGy showed little stabilization of the mechanical properties of PMMA, since it was observed mechanical degradation this system. Based on these results, PS and St showed to be the best radioprotective agents to PMMA. (author)

  2. Radiolytic stabilization of industrial poly(methyl methacrylate); Estabilizacao radiolitica do poli(metacrilato de metila) industrial

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Katia Aparecida da Silva

    2005-03-15

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed by radiation, does not change when PMMA (with additive) is irradiated. TGA analysis showed that the additive promotes thermal stability to the system, increasing decomposition temperature of PMMA. Spectroscopy analysis, FT-IR and RMN ({sup 1}H), showed that the radioprotector additive added to the system does not change the PMMA structure. Analysis on mechanical (tensile strength and elongation at break) and optical (yellowness index and refractive index) properties showed a good influence of the additive on polymer system. (author)

  3. Radiolytic stabilization of poly(methyl methacrylate) using commercial additives; Estabilizacao radiolitica do poli(metacrilato de metila) usando aditivos comerciais

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Katia Aparecida da Silva

    2000-04-01

    Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub g}) of PMMA (no additive) significantly changed by radiation does not change when PMMA (with additive) is irradiated. The spectroscopy analysis, FT-IR and NMR ({sup 1}H), showed that the radioprotector added to the system does not change the PMMA structure. (author)

  4. Lipase polystyrene giant amphiphiles.

    Science.gov (United States)

    Velonia, Kelly; Rowan, Alan E; Nolte, Roeland J M

    2002-04-24

    A new type of giant amphiphilic molecule has been synthesized by covalently connecting a lipase enzyme headgroup to a maleimide-functionalized polystyrene tail (40 repeat units). The resulting biohybrid forms catalytic micellar rods in water.

  5. EFFECT OF INCORPORATING EXPANDED POLYSTYRENE ...

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Incorporating expanded polystyrene granules in concrete matrix can produce lightweight polystyrene aggregate concrete of ... structure. [1] reported that the standard workability tests are not suitable for the polystyrene aggregate concrete since they are sensitive to the unit weight of concrete. [2] made ...

  6. Structural analysis of syndiotactic polystyrene

    Energy Technology Data Exchange (ETDEWEB)

    Mitani, Masahiro

    1988-09-01

    Since the stereostructure of a high-molecular compound includes three types of isotactic, atactic and sydiotactic structures, a high-molecular compound with excellent properties can be produced by controlling the stereogularity of the compound with the identical composition. The stereoregularity of a stereogular polystyrene, or syndiotactic polystyrene (SPS), which had been successfully synthesized recently was quantitatively determined and the open chain structure by polymerization was investigated by nuclear magnetic resonance spectroscopy. Two SPSs were synthesized from cis-beta-d/sub/1-styrene and trans-beta-d/sub/1-styrene with alpha, beta, beta-d/sub/3-styrene. The results of spectral analysis of these two SPSs indicate that the former is of trans-conformation and the latter is of gauche conformation and that accordingly the open chain structure by polymerization of SPS is of cis-open chain and SPS has a planar zigzag structure even in the solution. (5 figs, 9 refs)

  7. The surface modification of polystyrene

    International Nuclear Information System (INIS)

    Tremlett, C.

    2000-03-01

    Polymers have ideal bulk properties for many applications. However, adhesion to many polymers is poor without surface pretreatment. This can result, for example, in peeling paint and printing, adhesive joint failure and bio-incompatibility. In applications such as painting, printing, adhesive bonding and biocompatibility, various cleaning or surface chemical modifications may be employed. A commodity polymer where pretreatment is sometimes needed is polystyrene. This project investigated, in detail, the effects of a novel method of modification namely mediated electrochemical oxidation (MEO), as a mode of surface modification on polystyrene and a comparison was made with other polymers. The resulting modification was investigated using a range of surface analysis techniques to obtain complementary information. These included, X-ray photoelectron spectroscopy, contact angles, static secondary ion mass spectrometry, atomic force microscopy, chemical derivatization, scanning electron microscopy, attenuated total reflection Fourier Transform infrared spectroscopy and composite lap shear joint testing. It has been shown that MEO modifies the surface of polystyrene introduced oxygen mainly as hydroxyl groups, and a small number of carbonyl groups, that are positioned only on the backbone hydrocarbon chain. This modification improved adhesion, was stable and samples could be stored in aqueous media. The resulting hydroxylation was further derivatized using an amino acid to provide a specialised surface. This was very different from the multiple oxygen functionalities introduced in the comparison studies by UV/ozone and plasma treatments. (author)

  8. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

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

    2005-01-01

    /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...... for polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymers. The end use properties of SIS plasticized with polystyrene-b-alkyl, measured as tensile strength, is higher than for SIS plasticized with dioctyl adipate. The polystyrene-b-polybutadiene-b-polystyrene and polystyrene-bpoly(propylene glycol...

  9. Copolymers of fluorinated polydienes and sulfonated polystyrene

    Science.gov (United States)

    Mays, Jimmy W [Knoxville, TN; Gido, Samuel P [Hadley, MA; Huang, Tianzi [Knoxville, TN; Hong, Kunlun [Knoxville, TN

    2009-11-17

    Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

  10. 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.

  11. 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 ...

  12. 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...

  13. 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...

  14. Thermal Decomposition of Radiation-Damaged Polystyrene

    International Nuclear Information System (INIS)

    J Abrefah, J.; Klinger, G.S.

    2000-01-01

    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 polystyrene. The differences were in the

  15. Effect of Recycling in Post-Consumer Polystyrene Cups

    OpenAIRE

    Ahmed, Mehnaz

    2016-01-01

    The aim of the thesis was to recycle post-consumer polystyrene cups and to analyze the changes in mechanical and rheological properties of the recycled polystyrene. The me-chanical properties were tensile strength, Young’s modulus and the rheological proper-ties was melt flow index. In order to analyze the changes in properties, material testing results of pristine polystyrene were compared with the recycled polystyrene. The same polystyrene material was recycled and tested twice in order to ...

  16. Simple Coatings to Render Polystyrene Protein Resistant

    Directory of Open Access Journals (Sweden)

    Marcelle Hecker

    2018-02-01

    Full Text Available Non-specific protein adsorption is detrimental to the performance of many biomedical devices. Polystyrene is a commonly used material in devices and thin films. Simple reliable surface modification of polystyrene to render it protein resistant is desired in particular for device fabrication and orthogonal functionalisation schemes. This report details modifications carried out on a polystyrene surface to prevent protein adsorption. The trialed surfaces included Pluronic F127 and PLL-g-PEG, adsorbed on polystyrene, using a polydopamine-assisted approach. Quartz crystal microbalance with dissipation (QCM-D results showed only short-term anti-fouling success of the polystyrene surface modified with F127, and the subsequent failure of the polydopamine intermediary layer in improving its stability. In stark contrast, QCM-D analysis proved the success of the polydopamine assisted PLL-g-PEG coating in preventing bovine serum albumin adsorption. This modified surface is equally as protein-rejecting after 24 h in buffer, and thus a promising simple coating for long term protein rejection of polystyrene.

  17. 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.

  18. Comparative characteristics of polystyrene scintillation strips

    International Nuclear Information System (INIS)

    Gapienko, V.A.; Denisov, A.G.; Mel'nikov, E.A.

    1992-01-01

    Results are provided for a study of the main characteristics of polystyrene scintillation strips with a cross-section of 200 x 10 mm with two different scintillation-additive compositions: 1.5% p-terphenyl + 0.01% POPOP and 1.5% p-terphenyl + 0.01% DBP. The mean light-attenuation lengths are 180 cm and 260 cm, respectively, for strips with POPOP and DBP. The emittances of the polystyrene scintillators with DBP and POPOP additives have a ratio of 0.8:1.0 as recorded by an FEU-110 photomultiplier. 2 refs., 1 fig., 2 tabs

  19. 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

  20. 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.

  1. 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.

  2. Characterization of SWNT based Polystyrene Nanocomposites

    Science.gov (United States)

    Mitchell, Cynthia; Bahr, Jeffrey; Tour, James; Arepalli, Sivaram; Krishnamoorti, Ramanan

    2003-03-01

    Polystyrene nanocomposites with functionalized single walled carbon nanotubes (SWNTs), prepared by the in-situ generation and addition of organic diazonium compounds, were characterized using a range of structural and dynamic methods. These were contrasted to the properties of polystyrene composites prepared with unfunctionalized SWNTs at the same loadings. The functionalized nanocomposites demonstrated a percolated SWNT network structure at concentrations of 1 vol SWNT based composites at similar loadings of SWNT exhibited behavior comparable to that of the unfilled polymer. This formation of the SWNT network structure is because of the improved compatibility between the SWNTs and the polymer matrix due to the functionalization. Further structural evidence for the compatibility of the modified SWNTs and the polymer matrix will be discussed in the presentation.

  3. 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....

  4. Wettability control of polystyrene by ion implantation

    International Nuclear Information System (INIS)

    Suzuki, Yoshiaki; Kusakabe, Masahiro; Iwaki, Masaya

    1994-01-01

    The permanent effects of ion implantation on the improvement of wettability of polystyrene is investigated in relation to ion species and fluences. The He + , Ne + , Na + , N 2 + , O 2 + , Ar + , K + and Kr + ion implantations were performed at energies of 50 and 150 keV at room temperature. The fluences ranged from 1x10 15 to 1x10 17 ions/cm 2 . The results showed that the contact angle of water for Na + and K + implanted polystyrene decreased from 87 to 0 , as the fluences increased to 1x10 17 ions/cm 2 at an energy of 50 keV. The contact angle for Na + and K + implanted polystyrene did not change under ambient room conditions, even when time elapsed. However, the contact an gle for He + , C + , O + , Ne + , N 2 + , O 2 + , Ar + , and Kr + ion implanted specimens decreased slightly immediately after ion implantation. Results of X-ray photoelectron spectroscopy showed that the increase in the Na content in the surface of Na + implanted specimens were observed with increasing fluence. It is concluded that permanent improvement in wettability was caused by doping effects rather than by radiation effects from Na + and K + ion implantation. ((orig.))

  5. Local Segmental Dynamics and Stresses in Polystyrene - C$_{60}$ Mixtures

    OpenAIRE

    Vogiatzis, Georgios G.; Theodorou, Doros N.

    2014-01-01

    The polymer dynamics of homogeneous C$_{60}$-polystyrene mixtures in the molten state are studied via molecular simulations using two interconnected levels of representation for polystyrene nanocomposites: (a) A coarse-grained representation, in which each polystyrene repeat unit is mapped into a single "superatom" and each fullerene is viewed as a spherical shell. Equilibration of coarse-grained polymer-nanoparticle systems at all length scales is achieved via connectivity-altering Monte Car...

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

    OpenAIRE

    MOTTA,L. A. C.; VIEIRA,J. G.; OMENA,T. H.; FARIA,F. A. C.; RODRIGUES FILHO,G.; ASSUNÇÃO,R. M. N.

    2016-01-01

    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...

  7. Fabrication of polystyrene porous films with gradient pore structures

    International Nuclear Information System (INIS)

    Yan Hongwei; Zhang Lin; Li Bo; Yin Qiang

    2010-01-01

    Silica opals and multilayer heterostructures were fabricated by vertical deposition technique. Polystyrene inverse opals and gradient porous structures were obtained by colloidal templating, in order to control the pore microstructure of polymer porous materials. As shown in the scanning electron microscopy images, the polystyrene porous structures are precise replicas of inverse structures of the original templates. After being infiltrated with the polystyrene, the photonic stop-band position of the opal composite is redshifted compared with the original template, and it is blueshifted after the opal template being removed. The filling ratio of polystyrene was calculated according to the Bragg formula. (authors)

  8. Circularly polarized luminescence of syndiotactic polystyrene

    Science.gov (United States)

    Rizzo, Paola; Abbate, Sergio; Longhi, Giovanna; Guerra, Gaetano

    2017-11-01

    Syndiotactic polystyrene (s-PS) films, when crystallized from the amorphous state by temporary sorption of non-racemic guest molecules (like carvone) not only exhibit unusually high optical activity, both in the UV-Visible and Infrared ranges, but also present circularly polarized luminescence (CPL) with high dissymmetry ratios (g = ΔI/I values in the range 0.02-0.03). Experimental evidences provide support, rather than to the usual molecular circular dichroism, to a supramolecular chiral optical response being extrinsic to the site of photon absorption and emission, possibly associated with a helical morphology of s-PS crystallites.

  9. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, R., E-mail: raspberry@lanl.gov; Danly, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Glebov, V. Yu. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Hurlbut, C. [Eljen Technology, Sweetwater, Texas 79556 (United States)

    2016-04-15

    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.

  12. 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...

  13. 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.

  14. Influence of recycled polystyrene beads on cement paste properties

    Directory of Open Access Journals (Sweden)

    Maaroufi Maroua

    2018-01-01

    Full Text Available In order to keep up with the requirements of sustainable development, there is a growing interest towards reducing the energy consumption in the construction and rehabilitation of buildings and the promotion of recycling waste in building materials. The use of recycled polystyrene beads in cement-based materials composition constitutes a solution to improve the insulation in buildings. This allows also limiting landfill by reusing the polystyrene waste. The aim of this study is to compare some properties and performances of a cement paste containing polystyrene beads to a reference paste designed with only the same cement. An experimental campaign was conducted and the obtained results showed that adding recycled polystyrene beads to a cement paste improves its hygro-thermal properties. Further studies are however necessary to better understand the real role of the polystyrene beads in the heat and mass transfers.

  15. 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.

  16. Correlated dewetting patterns in thin polystyrene films

    International Nuclear Information System (INIS)

    Neto, Chiara; Jacobs, Karin; Seemann, Ralf; Blossey, Ralf; Becker, Juergen; Gruen, Guenther

    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

  17. Adsorption of amphipathic dendrons on polystyrene nanoparticles.

    Science.gov (United States)

    Sakthivel, T; Florence, A T

    2003-03-18

    Adsorption of dendrons onto nanoparticles may provide new model structures which may be useful in drug and gene delivery. Tritiated amphipathic dendrons having three lipidic (C(14)) chains coupled to branched (dendritic) lysine head groups with 8, 16 or 32 free terminal amino groups have been synthesised by solid phase peptide techniques. The interaction between these tritiated dendrons and 200 nm polystyrene latex nanoparticles was investigated in phosphate buffered saline. The amount of dendron adsorbed increased with increasing concentration of dendrons and then decreased. Maximum adsorption of dendrons per gram of nanoparticles was found to be between 8.2 and 84 x 10(-6)M, the amounts adsorbed being inversely proportional to the number of amino groups present in the molecule. The number of dendron molecules adsorbed per nanoparticle was found to be between 430 and 4421. The degree of adsorption was found to be slightly altered by the temperature. Copyright 2002 Elsevier Science B.V.

  18. 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

  19. 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.

  20. Synthesis and properties of deuterated polystyrene

    International Nuclear Information System (INIS)

    Liu Chang; Jin Rong; Xu Yewei; Zhang Lin; Yan Hongwei; Du Kai; Wei Chengfu

    2012-01-01

    Deuterated poly(vinylcyclohexane) (D-PVCH, C 8 H 8 D 6 ) was successfully prepared via deuterated catalytic technology of polystyrene (PS). The structure of D-PVCH was characterized by FT-IR and 1 HNMR spectroscopy, and the results show good agreement with the proposed structure and the deuterated ratio is 41.5%. DSC and TG analyses of the D-PVCH show that D-PVCH possesses good thermal stability (glass transition temperature of 125 ℃, 5% weight loss temperature of 403 ℃). Additionally, D-PVCH dissolves in common solvents such as petroleum ether, cyclohexane and toluene at room temperature. Compared with PS, D-PVCH possesses better thermal stability and improved solubility. (authors)

  1. Combined effect of gamma radiation and stress cracking in polystyrene

    International Nuclear Information System (INIS)

    Amorim, Fernando A.; Rabello, Marcelo S.; Silva, Leonardo G.A.

    2011-01-01

    This study aimed to evaluate the combined effect of gamma radiation and stress cracking in polystyrene. Three different grades of polystyrene were analysed. The material was submitted to tensile tests and relaxation, analysis of molecular weight and determination of crosslinking. The results showed an increase in tensile strength in the specimens that had been exposed to radiation. The higher the molecular weight polystyrene showed better mechanical properties and after suffering the effects of gamma radiation there was an increase of 5.67% in the resistance to stress cracking effects. (author)

  2. Synthesis of micro-sized polystyrene magnetic particles

    International Nuclear Information System (INIS)

    Neves, Juliete S.; Suarez, Paulo A.Z.; Umpierre, Alexandre P.; Machado, Fabricio; Souza Junior, Fernando G. de

    2011-01-01

    The present work illustrates the synthesis of spherical and micro-sized polystyrene magnetic particles by using a water-based suspension polymerization process to incorporate in situ surface modified superparamagnetic Fe 3 O 4 nanoparticles. The crystallite size of Fe 3 O 4 was determined to be equal to 7.7 nm, based on Scherrer's equation and XRD measurement. According to EDX analyses, Fe 3 O 4 / polystyrene nanocomposites particles show strong characteristic peaks Kα and Kβ of iron at the interval from 6.38 KeV to 7.04 KeV with an amount of iron in the samples equal to 98 %, indicating that the inorganic material dispersed in the polystyrene matrix is essentially Fe in the form of iron oxide (Fe 3 O 4 ). The obtained polymeric materials presented good magnetic behavior, indicating that the modified Fe 3 O 4 nanoparticles were successfully dispersed in the polystyrene particles. (author)

  3. ESR studies of the radiation effects on polystyrene

    International Nuclear Information System (INIS)

    Garrett, R.W.; O'Donnell, J.H.; Pomery, P.J.

    1976-01-01

    The aim of this work was to investigate the polystyrene system (both pure and commercial samples) to elucidate the type and percentage of each paramagnetic species upon exposure to various irradiation doses. The size of dose plays a vital role in the type of spectra obtained. Upon irradiation in vacuo, polystyrene displays ESR spectra which are basically triplet in character but the line spacing and intensities of components are observed to depend on the magnitude of the irradiation dose. G value for the total radicals present and for the individual species present as a function of dose have been obtained. The relative concentration of each paramagnetic species has been determined through computer simulation of the observed ESR spectra. The relative stability of the different species with respect to temperature is discussed. The results for deuterated polystyrene is used to support those obtained for the unsubstituted polystyrene system. (author)

  4. 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.

  5. Constancy in composition of polystyrene and polymethylmethacrylate plastics

    International Nuclear Information System (INIS)

    Schulz, R.J.; Nath, R.

    1979-01-01

    Variations in the atomic compostion, and mass and electron densities of polystyrene and polymethylmethacrylate (PMM) plastics were assessed from experimentally determined mass attenuation coefficients for 125 I and 137 Cs gamma rays. The means and standard deviations in the mass densities of 16 samples of PMM and 10 samples of polystyrene were found to be 1.174 +- 1.4% and 1.042 +- 0.6% g/cm 3 , respectively. Based upon transmission measurements on various solutions of ethyl alcohol in water, the standard deviations in the effective atomic numbers of PMM and polystyrene were determined to be 0.77% and 1.3%, respectively. Based upon experimentally determined mass attenuation coefficients for 137 Cs, the standard deviations in electron density for PMM and polystyrene were 0.5% and 1.2%, respectively. Similar measurements on tap water and two grades of distilled water failed to detect any differences in atomic composition

  6. Behavior of positronium in polystyrene and its derivatives

    International Nuclear Information System (INIS)

    Honda, Y.; Watanabe, M.; Tashiro, M.; Terashima, Y.; Miyamoto, K.; Kimura, N.; Tagawa, S.

    2003-01-01

    The polystyrene, poly(4-bromostyrene) and poly(4-vinylphenol) are investigated using slow positron beam based on electron linac. There was a difference in the intensity of long-lived component of lifetime in o-Ps (τ 3 ). The S-parameter and the intensity of τ 3 were strongly influenced by the presence of the substituents of polystyrene. In thin films, irradiation effect caused by positron beam was observed

  7. On the Importance of Purification of Sodium Polystyrene Sulfonate

    OpenAIRE

    Sen, Akhil K.; Roy, Sandip; Juvekar, Vinay A.

    2012-01-01

    Ion exchange is commonly employed for purification of sodium polystyrene sulfonate (NaPSS), a molecule widely used as a model polyelectrolyte. However, the present work demonstrates that the ion exchange process itself may introduce some extraneous species into NaPSS samples by two possible mechanisms: (i) chemical transformation of polystyrene sulfonic acid (HPSS), a relatively unstable intermediate formed during ion exchange and (ii) release of small amount of “condensed” acid from cationic...

  8. The polymerization of aniline in polystyrene latex particles

    Czech Academy of Sciences Publication Activity Database

    Blinova, Natalia V.; Reynaud, S.; Roby, F.; Trchová, Miroslava; Stejskal, Jaroslav

    2010-01-01

    Roč. 160, 15/16 (2010), s. 1598-1602 ISSN 0379-6779 R&D Projects: GA AV ČR IAA400500905; GA ČR GA203/08/0686; GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * polystyrene latex * polyaniline-polystyrene composite Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.871, year: 2010

  9. Formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles using sulfonated polystyrene as template.

    Science.gov (United States)

    Hazarika, Mousumi; Arunbabu, Dhamodaran; Jana, Tushar

    2010-11-15

    We report formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles from a new blend system consisting of an amorphous polymer polybenzimidazole (PBI) and an ionomer sodium salt of sulfonated polystyrene (SPS-Na). The ionomer used for the blending is spherical in shape with sulfonate groups on the surface of the particles. An in depth investigation of the blends at various sulfonation degrees and compositions using Fourier transform infrared (FT-IR) spectroscopy provides direct evidence of specific hydrogen bonding interactions between the N-H groups of PBI and the sulfonate groups of SPS-Na. The disruption of PBI chains self association owing to the interaction between the functional groups of these polymer pairs is the driving force for the blending. Thermodynamical studies carried out by using differential scanning calorimeter (DSC) establish partially miscible phase separated blending of these polymers in a wider composition range. The two distinguishable glass transition temperatures (T(g)) which are different from the neat components and unaltered with the blends composition attribute that the domain size of heterogeneity (d(d)) of the blends is >20 nm since one of the blend component (SPS-Na particle) diameter is ∼70 nm. The diminish of PBI chains self association upon blending with SPS-Na particles and the presence of invariant T(g)'s of the blends suggest the wrapping of PBI chains over the SPS-Na spherical particle surface and hence resulting a core-shell morphology. Transmission electron microscopy (TEM) study provides direct evidence of core-shell nanoparticle formation; where core is the polystyrene and shell is the PBI. The sulfonation degree affects the blends phase separations. The higher degree of sulfonation favors the disruption of PBI self association and thus forms partially miscible two phases blends with core-shell morphology. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. 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.

  11. ''Nonisolated-sensor'' solid polystyrene absorbed dose measurements

    International Nuclear Information System (INIS)

    Zeitz, L.; Laughlin, J.S.

    1982-01-01

    A ''nonisolated-sensor'' solid polystyrene calorimeter was constructed to test the role of thermal diffusion in limiting the length of irradiation time during which temperature measurements with nonisolated sensors could be made sufficiently free of drift for determining dose with radiation fields such as gamma rays, x rays, and high-energy electrons. From measured ratios of dose at 5.0 and 0.5 cm in polystyrene and comparisons to dose measurements with a polystyrene parallel-plate (pancake) ion chamber, it was shown that thermal diffusion is sufficiently small in polystyrene to permit accurate measurements for irradiation periods of less than 20 min. Comparison of the absorbed dose measurements and depth dose ratios with pancake ion chambers and calorimeter showed, that within the precision and accuracy of the two measuring systems, there is close agreement. The nonisolated-sensor solid polystyrene calorimeter has the interesting features of (i) simplicity of construction, (ii) simplicity of operation without vacuum or feedback for temperature control, (iii) capability of simultaneous measurements at several depths and off-axis positions, (iv) the very small thermal defect correction with polystyrene, and (v) operation with the calorimeter in any orientation

  12. Nonisolated-sensor solid polystyrene absorbed dose measurements

    International Nuclear Information System (INIS)

    Zeitz, L.; Laughlin, J.S.

    1982-01-01

    A nonisolated-sensor solid polystyrene calorimeter was constructed to test the role of thermal diffusion in limiting the length of irradiation time during which temperature measurements with nonisolated sensors could be made sufficiently free of drift for determining dose with radiation fields such as gamma rays, x rays, and high-energy electrons. From measured ratios of dose at 5.0 and 0.5 cm in polystyrene and comparisons to dose measurements with a polystyrene parallel-plate (pancake) ion chamber, it was shown that thermal diffusion is sufficiently small in polystyrene to permit accurate measurements for irradiation periods of less than 20 min. Comparison of the absorbed dose measurements and depth dose ratios with pancake ion chambers and calorimeter showed, that within the precision and accuracy of the two measuring systems, there is close agreement. The nonisolated-sensor solid polystyrene calorimeter has the interesting features of (i) simplicity of construction, (ii) simplicity of operation without vacuum or feedback for temperature control, (iii) capability of simultaneous measurements at several depths and off-axis positions, (iv) the very small thermal defect correction with polystyrene, and (v) operation with the calorimeter in any orientation

  13. A novel anion exchange membrane from polystyrene (ethylene butylene) polystyrene: Synthesis and characterization

    International Nuclear Information System (INIS)

    Vinodh, Rajangam; Ilakkiya, Arjunan; Elamathi, Swaminathan; Sangeetha, Dharmalingam

    2010-01-01

    We look forward for an eco-friendly hydrocarbon polymer with higher molecular weight for the preparation of an anion exchange membrane. Polystyrene ethylene butylene polystyrene (PSEBS) was chosen as the polymer matrix. The anion exchange membrane was prepared from PSEBS tri-block co-polymer and then the properties were characterized for alkaline fuel cell application. The preparation of anion exchange polymer involved two steps namely chloromethylation and quaternization. The anion exchange membrane with high conductivity has been prepared by introducing quaternary ammonium groups in to the polymer. Finally, the membrane was prepared using solution casting method. The solution casting method yields highly hydrophilic membranes with uniform structure that were suitable for electrochemical applications. The efficiency of the entrapment was monitored by swelling ratio, chemical stability and ion exchange measurement. The characteristic structural properties of the membrane were investigated by FT-IR spectroscopy and 1 H NMR spectroscopy. The thermal stability of the membrane was characterized by TGA, DSC and DMA (dynamic mechanical analysis). The prepared uniform electrolyte membrane in this study has high thermal and chemical stability. The surface morphology and elemental composition of the quaternized PSEBS was determined by SEM-EDXA techniques, respectively. The measured hydroxyl ion conductivity of the synthesized alkaline PSEBS polymer electrolyte membrane showed ionic conductivity in the range of 10 -3 S/cm in deionized water at room temperature. It was found that the substitution provided a flexible, chemically and thermally stable membrane. Hence, the membrane will have potential application in the alkaline fuel cell.

  14. Modelling of Radiolytical Proceses in Polystyrenic Structures

    International Nuclear Information System (INIS)

    Postolache, C.

    2006-01-01

    The behavior of polystyrene, poly α-methylstyrene and poly β-methylstyrene structures in ionizing fields was analyzed using computational methods. In this study, the primary radiolytic effect was evaluated using a free radical mechanism. Molecular structures were built and geometrical optimized using quantum-chemical methods. Binding energies for different quantum states and peripheral orbitals distribution were determined. Based on obtained results it was proposed an evaluation model of radiolytical processes in polymers in solid phase. Suggested model suppose to distinguish the dominant processes by binding energies values analysis and LUMO peripheral orbital distribution. Computed binding energies analysis of energetically optimized molecular structures in ionized state (charge +1, multiplicity 2) reveals a high similitude of obtained binding energies for ionized states. The same similitude was observed also in case of total binding energies for neutral state (charge 0, multiplicity 1). Analyzed molecular structures can be associated with ionized molecule state right after one electron capture. This fact suggests that the determined stage of radiolitical fragmentation act is intermediate state of ionized molecule. This molecule captured one electron but it had no necessary time for atoms rearrangement in the molecule for new quantum state. This supposition is in accordance with literature, the time period between excitation act and fragmentation act being lower than 10 - 15 seconds. Based on realized model could be explained the behavior differences of polymeric structures in ionizing radiation field. Preferential fracture of main chains in fragmentation poly α-methylstirene can be explained in accordance with proposed model by C-C from main C bonding energies decreasing in the neighboring of quaternary C

  15. 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.

  16. Polystyrene nanoparticles affect Xenopus laevis development

    International Nuclear Information System (INIS)

    Tussellino, Margherita; Ronca, Raffaele; Formiggini, Fabio; Marco, Nadia De; Fusco, Sabato; Netti, Paolo Antonio; Carotenuto, Rosa

    2015-01-01

    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

  17. 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.

  18. Human plasma fibrinogen adsorption and platelet adhesion to polystyrene.

    Science.gov (United States)

    Tsai, W B; Grunkemeier, J M; Horbett, T A

    1999-02-01

    The purpose of this study was to further investigate the role of fibrinogen adsorbed from plasma in mediating platelet adhesion to polymeric biomaterials. Polystyrene was used as a model hydrophobic polymer; i.e., we expected that the role of fibrinogen in platelet adhesion to polystyrene would be representative of other hydrophobic polymers. Platelet adhesion was compared to both the amount and conformation of adsorbed fibrinogen. The strategy was to compare platelet adhesion to surfaces preadsorbed with normal, afibrinogenemic, and fibrinogen-replenished afibrinogenemic plasmas. Platelet adhesion was determined by the lactate dehydrogenase (LDH) method, which was found to be closely correlated with adhesion of 111In-labeled platelets. Fibrinogen adsorption from afibrinogenemic plasma to polystyrene (Immulon I(R)) was low and polystyrene preadsorbed with fibrinogen-replenished afibrinogenemic plasma. Addition of even small, subnormal concentrations of fibrinogen to afibrinogenemic plasma greatly increased platelet adhesion. In addition, surface-bound fibrinogen's ability to mediate platelet adhesion was different, depending on the plasma concentration from which fibrinogen was adsorbed. These differences correlated with changes in the binding of a monoclonal antibody that binds to the Aalpha chain RGDS (572-575), suggesting alteration in the conformation or orientation of the adsorbed fibrinogen. Platelet adhesion to polystyrene preadsorbed with blood plasma thus appears to be a strongly bivariate function of adsorbed fibrinogen, responsive to both low amounts and altered states of the adsorbed molecule. Copyright 1999 John Wiley & Sons, Inc.

  19. A novel anion exchange membrane from polystyrene (ethylene butylene) polystyrene: Synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Vinodh, Rajangam; Ilakkiya, Arjunan; Elamathi, Swaminathan [Department of Chemistry, Anna University Chennai, Sardar Patel Road, Chennai 600025, Tamil Nadu (India); Sangeetha, Dharmalingam, E-mail: sangeetha@annauniv.ed [Department of Chemistry, Anna University Chennai, Sardar Patel Road, Chennai 600025, Tamil Nadu (India)

    2010-02-25

    We look forward for an eco-friendly hydrocarbon polymer with higher molecular weight for the preparation of an anion exchange membrane. Polystyrene ethylene butylene polystyrene (PSEBS) was chosen as the polymer matrix. The anion exchange membrane was prepared from PSEBS tri-block co-polymer and then the properties were characterized for alkaline fuel cell application. The preparation of anion exchange polymer involved two steps namely chloromethylation and quaternization. The anion exchange membrane with high conductivity has been prepared by introducing quaternary ammonium groups in to the polymer. Finally, the membrane was prepared using solution casting method. The solution casting method yields highly hydrophilic membranes with uniform structure that were suitable for electrochemical applications. The efficiency of the entrapment was monitored by swelling ratio, chemical stability and ion exchange measurement. The characteristic structural properties of the membrane were investigated by FT-IR spectroscopy and {sup 1}H NMR spectroscopy. The thermal stability of the membrane was characterized by TGA, DSC and DMA (dynamic mechanical analysis). The prepared uniform electrolyte membrane in this study has high thermal and chemical stability. The surface morphology and elemental composition of the quaternized PSEBS was determined by SEM-EDXA techniques, respectively. The measured hydroxyl ion conductivity of the synthesized alkaline PSEBS polymer electrolyte membrane showed ionic conductivity in the range of 10{sup -3} S/cm in deionized water at room temperature. It was found that the substitution provided a flexible, chemically and thermally stable membrane. Hence, the membrane will have potential application in the alkaline fuel cell.

  20. Variable Lysozyme Transport Dynamics on Oxidatively Functionalized Polystyrene Films.

    Science.gov (United States)

    Moringo, Nicholas A; Shen, Hao; Tauzin, Lawrence J; Wang, Wenxiao; Bishop, Logan D C; Landes, Christy F

    2017-10-17

    Tuning protein adsorption dynamics at polymeric interfaces is of great interest to many biomedical and material applications. Functionalization of polymer surfaces is a common method to introduce application-specific surface chemistries to a polymer interface. In this work, single-molecule fluorescence microscopy is utilized to determine the adsorption dynamics of lysozyme, a well-studied antibacterial protein, at the interface of polystyrene oxidized via UV exposure and oxygen plasma and functionalized by ligand grafting to produce varying degrees of surface hydrophilicity, surface roughness, and induced oxygen content. Single-molecule tracking indicates lysozyme loading capacities, and surface mobility at the polymer interface is hindered as a result of all functionalization techniques. Adsorption dynamics of lysozyme depend on the extent and the specificity of the oxygen functionalities introduced to the polystyrene surface. Hindered adsorption and mobility are dominated by hydrophobic effects attributed to water hydration layer formation at the functionalized polystyrene surfaces.

  1. Photooxidation of polystyrene: irradiation at 254 and 365 nm

    International Nuclear Information System (INIS)

    Otocka, E.P.; Curran, S.; Porter, R.S.

    1983-01-01

    Studies have been made of the near surface photooxidation of atactic polystyrene films prepared in the absence of air. The samples were photooxidized on exposure to air at two frequencies, 254 and 365 nm, using a calibrated mercury irradiation source with filters. Most studies were made at 40 0 C and as a function of irradiation time with the reactions characterized by changes in molecular weight and composition. The former was evaluated by gel permeation chromatography and the latter by transmission Fourier transform infrared ir spectroscopy and by multiple-internal-reflectance ir spectra using different angles and different crystals to evaluate compositions as a function of film depth. Species identified in photooxidation include the generation of hydroperoxides and the appearance of carbonyl bands with the latter identified by the spectral shift associated with the exposure of the photooxidized polystyrene surface to ammonia. These results suggest that principal products of near-surface oxidation of polystyrene are carboxylic acids. 6 figures, 1 table

  2. Partially-Functionalized Isotactic Polystyrene with Blocky Comonomer Segments

    Science.gov (United States)

    Siegel, Ariel; Powers, Wayne; Ryu, Chang Y.

    2012-02-01

    Isotactic polystyrenes (iPSs) have been functionalized in solution, while the accessibility of functionalizing agent is limited by the formation of crystalline domains at various temperatures. The chemical system used is the borylated isotactic polystyrene system, and we investigated the temperature effects on reaction kinetics to ultimately control the blockiness of borylated segments in the resulting copolymer. The chemical composition of partially borylated iPS reaches a steady state that is dependent on temperature. This synthesis has been performed at many different temperatures, with different steady states being reached at different temperatures. Further analysis by differential scanning calorimetry (DSC) has shown that the higher temperature reactions have greater effect on breaking down the crystal lattice structure of the isotactic polystyrene. As a result, the lower temperature reactions affect the crystalline structure less, and the resulting copolymer has more blockiness.

  3. Polystyrene nanoparticles activate ion transport in human airway epithelial cells

    Directory of Open Access Journals (Sweden)

    McCarthy J

    2011-06-01

    Full Text Available J McCarthy1, X Gong2, D Nahirney2, M Duszyk2, MW Radomski11School of Pharmacy and Pharmaceutical Sciences, Panoz Institute, Trinity College Dublin, Dublin, Ireland; 2Department of Physiology, University of Alberta, Edmonton, Alberta, CanadaBackground: Over the last decade, nanotechnology has provided researchers with new nanometer materials, such as nanoparticles, which have the potential to provide new therapies for many lung diseases. In this study, we investigated the acute effects of polystyrene nanoparticles on epithelial ion channel function.Methods: Human submucosal Calu-3 cells that express cystic fibrosis transmembrane conductance regulator (CFTR and baby hamster kidney cells engineered to express the wild-type CFTR gene were used to investigate the actions of negatively charged 20 nm polystyrene nanoparticles on short-circuit current in Calu-3 cells by Ussing chamber and single CFTR Cl- channels alone and in the presence of known CFTR channel activators by using baby hamster kidney cell patches.Results: Polystyrene nanoparticles caused sustained, repeatable, and concentration-dependent increases in short-circuit current. In turn, these short-circuit current responses were found to be biphasic in nature, ie, an initial peak followed by a plateau. EC50 values for peak and plateau short-circuit current responses were 1457 and 315.5 ng/mL, respectively. Short-circuit current was inhibited by diphenylamine-2-carboxylate, a CFTR Cl- channel blocker. Polystyrene nanoparticles activated basolateral K+ channels and affected Cl- and HCO3- secretion. The mechanism of short-circuit current activation by polystyrene nanoparticles was found to be largely dependent on calcium-dependent and cyclic nucleotide-dependent phosphorylation of CFTR Cl- channels. Recordings from isolated inside-out patches using baby hamster kidney cells confirmed the direct activation of CFTR Cl- channels by the nanoparticles.Conclusion: This is the first study to identify

  4. Radiation-induced chemical processes in polystyrene scintillators

    International Nuclear Information System (INIS)

    Milinchuk, V.K.; Bolbit, N.M.; Klinshpont, E.R.; Tupikov, V.I.; Zhdanov, G.S.; Taraban, S.B.; Shelukhov, I.P.; Smoljanskii, A.S.

    1999-01-01

    The regularities established for macroradical accumulation and intensity of radioluminescence under γ-irradiation of a polystyrene scintillator prove benzyl macroradicals to be efficient quenchers of the excited scintillator molecules. Dissolved oxygen was determined to have a constant of the quenching rate 100 times lower than that of macroradicals. Oxygen is an efficient antirad because of participating in oxidation reactions and subsequent recombination of macroradicals. The method was developed to obtain a polymeric scintillator with a polystyrene matrix containing a dispersed system of pores and channels. Radiation resistance of such a scintillator is 5-10 times higher than that of standard types

  5. Preparation of Track Etch Membrane Filters Using Polystyrene Film

    International Nuclear Information System (INIS)

    Kaewsaenee, Jerawut; Ratanatongchai, Wichian; Supaphol, Pitt; Visal-athaphand, Pinpan

    2007-08-01

    Full text: Polystyrene nuclear track etch membrane filters was prepared by exposed 13 .m thin film polystyrene with fission fragment. Nuclear latent track was enlarged to through hole on the film by etching with 80 o C 40% H 2 SO 4 with K 2 Cr 2 O 7 solution for 6-10 hour. The hole size was depend on concentration of etching solution and etching time with 1.3-3.4 .m hole diameter. The flow rate test of water was 0.79-1.56 mm cm-2 min-1 at 109.8-113.7 kPa pressure

  6. Optical Properies of Polystyrene Films Doped by Methyl Green Dye

    Directory of Open Access Journals (Sweden)

    Asrar A. Saeed

    2017-11-01

    Full Text Available Effects of methyl green (MG dye on the optical properties of polystyrene (PS have been studied. Pure polystyrene and MG doped PS films were prepared by using casting method. These films were characterized using UV/VIS spectrophotometer technique in order to estimate the type of electric transition which was found to be indirect transition. The value of the optical energy gap was decreased with increasing doping ratios of methyl green dye. Absorption coefficient, extinction coefficient, refractive index and energy gap have been also investigated; it was found that all the above parameters affects by doping dye.

  7. HYDRATION AND MICROSTRUCTURE OF BLENDED CEMENT WITH SODIUM POLYSTYRENE SULFONATE

    Directory of Open Access Journals (Sweden)

    Weifeng Li

    2017-03-01

    Full Text Available Polystyrene foamed plastic wastes are a kind of environmental pollutant. It could be recycled in cement industry as a chemical agent. In this paper, the effects of sodium polystyrene sulfonate (SPS on the hydration and microstructure of blended cement were investigated by calorimetry, X-ray diffraction (XRD, scanning electron microscopy (SEM and mercury intrusion porosimetry (MIP. SPS slightly delayed the hydration of alite and decreased its hydration degree. SPS did not change the phase compositions during hydration. SPS changed the morphology of ettringite (AFt and decreased the pore volumes and the sizes of pores.

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

    Indian Academy of Sciences (India)

    Unknown

    DMF results in the formation of polystyrene-anchored monobasic bidentate Schiff base, ... studied ligands in coordination chemistry. On ac- count of their pronounced coordinating properties, a ... Experimental ... temperature and then was suction-filtered, washed .... vent due to its high dielectric constant and its ability.

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

    African Journals Online (AJOL)

    The adsorption capacity of lysozyme (chicken egg white) from aqueous solutions unto silica and polystyrene interfaces was studied at varying lysozyme concentrations and ionic strength. The studies revealed an increase in adsorption capacity with increase in concentration and with maximum adsorption densities of 1.34 ...

  10. Spectroscopic and antimicrobial studies of polystyrene films under ...

    Indian Academy of Sciences (India)

    Spectroscopic and antimicrobial studies of polystyrene films under air plasma and He-Ne laser treatment ... The parameters such as (1) surface area by contact angle measurements, (2) quality of material before and after treatment by SEM and FTIR spectra and (3) material characterization by UV-vis spectra were studied.

  11. 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 ...

  12. 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...

  13. Melt dispersion of thermoplastic polystyrene in polymer polyols

    NARCIS (Netherlands)

    2009-01-01

    Polystyrene is dispersed into a polyol via a mechanical dispersion process. A stabilizer is present to stabilize the dispersed polymer particles. The stabilizer includes a copolymer of (1) from 10 to 70% by weight of a branched polyol which has a molecular weight of from 4000 to 20,000, from 0.2 to

  14. Fabrication of polystyrene/agave particle biocomposites using ...

    Indian Academy of Sciences (India)

    Polystyrene (PS) composites reinforced with ungrafted and acrylonitrile (AN) grafted agave particles (AgP) have been prepared with 10–30% particle content by weight using compression molding technique. The composite specimens thus prepared were subjected to the evaluation of mechanical, chemical, flammability and ...

  15. Preparation and thermal properties of polystyrene/silica nanocomposites

    Czech Academy of Sciences Publication Activity Database

    Bera, O.; Pilić, B.; Pavličević, J.; Jovičić, M.; Holló, B.; Meszaros Szecsenyi, K.; Špírková, Milena

    2011-01-01

    Roč. 515, č. 1/2 (2011), s. 1-5 ISSN 0040-6031 R&D Projects: GA AV ČR(CZ) IAAX08240901 Institutional research plan: CEZ:AV0Z40500505 Keywords : polystyrene * silica nanoparticles * nanocomposites Subject RIV: JI - Composite Materials Impact factor: 1.805, year: 2011

  16. Microporous polystyrene particles for selective carbon dioxide capture.

    Science.gov (United States)

    Kaliva, Maria; Armatas, Gerasimos S; Vamvakaki, Maria

    2012-02-07

    This study presents the synthesis of microporous polystyrene particles and the potential use of these materials in CO(2) capture for biogas purification. Highly cross-linked polystyrene particles are synthesized by the emulsion copolymerization of styrene (St) and divinylbenzene (DVB) in water. The cross-link density of the polymer is varied by altering the St/DVB molar ratio. The size and the morphology of the particles are characterized by scanning and transmission electron microscopy. Following supercritical point drying with carbon dioxide or lyophilization from benzene, the polystyrene nanoparticles exhibit a significant surface area and permanent microporosity. The dried particles comprising 35 mol % St and 65 mol % DVB possess the largest surface area, ∼205 m(2)/g measured by Brunauer-Emmett-Teller and ∼185 m(2)/g measured by the Dubinin-Radushkevich method, and a total pore volume of 1.10 cm(3)/g. Low pressure measurements suggest that the microporous polystyrene particles exhibit a good separation performance of CO(2) over CH(4), with separation factors in the range of ∼7-13 (268 K, CO(2)/CH(4) = 5/95 gas mixture), which renders them attractive candidates for use in gas separation processes.

  17. Radiation damage studies on polystyrene-based scintillators

    International Nuclear Information System (INIS)

    Britvich, G.I.; Peresypkin, A.I.; Rykalin, V.I.

    1991-01-01

    The radiation resistance of polystyrene-based scintillators containing various scintillation dopes is reported. All samples were irradiated to 137 Cs gamma rays in air at room temperature. The examination of radiation resistance of about thirty fluorescence compounds has been made. The most radiation-hard fluores are X25, X31, 3HF and M3HF. 1 fig.; 6 tabs

  18. Polystyrene cryostat facilitates testing tensile specimens under liquid nitrogen

    Science.gov (United States)

    Shogan, R. P.; Skalka, R. J.

    1967-01-01

    Lightweight cryostat made of expanded polystyrene reduces eccentricity in a tensile system being tested under liquid nitrogen. The cryostat is attached directly to the tensile system by a special seal, reducing misalignment effects due to cryostat weight, and facilitates viewing and loading of the specimens.

  19. 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

  20. Steady shear rheology of dilute polystyrene particle gels

    NARCIS (Netherlands)

    Folkersma, R.; Diemen, van A.J.G.; Laven, J.; Stein, H.N.

    1999-01-01

    This paper describes an experimental study on dispersions of monodisperse polystyrene (PS) spheres with a typical radius of 1 µm, dispersed in an electrolyte at high ionic strength, screening the electrostatic repulsion. These suspensions gelate at rest even at low volume fractions of PS particles.

  1. 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.

  2. Sorption behaviour of polystyrene grafted sago starch in various solvents

    International Nuclear Information System (INIS)

    Janarthanan, P.; Yunus, W.M.Z.W.; Ahmed, M.B.; Rahman, M.Z.; Haron, M.J.; Silong, S.

    2001-01-01

    This paper describes swelling properties of polystyrene grafted sago starch in dimethyl sulfoxide (DMSO); chloroform (CHCl/sub 3/), water, acetone carbon tetrachloride (CCl/sub 4/) cyclohexanone and toluene. The copolymer for this study was prepared by grafting styrene onto sago starch using ceric ammonium nitrate as a redox initiator. Solvent uptake of the copolymer with respect to time was obtained by soaking the samples in chosen solvents for various time intervals at 25+-1 degree centigrade. The results obtained from swelling of polystyrene grafted sago starch in polar and non polar solvents showed that the percentage of swelling at equilibrium and the swelling rate coefficient decreased in the following order: DMSO > water > acetone cyclohexanone approx. CHCl/sub 3/ > toluene approx. CCl/sub 4/. Dimethyl sulfoxide showed the highest percentage of swelling at equilibrium that is 765%. Diffusions of the solvents onto the polymers were found to be of a Fickian only for DMSO. (author)

  3. Renewable aromatics from the degradation of polystyrene under mild conditions

    Directory of Open Access Journals (Sweden)

    Nouf M. Aljabri

    2017-12-01

    Full Text Available 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 conditions 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. Keywords: Polystyrene, Bimetallic, Low-temperature, Catalytic degradation

  4. Hydrophilic nanoporous polystyrenes and 1,2-polybutadienes

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Vigild, Martin Etchells

    2008-01-01

    Nanoporous polymers from ordered block copolymers having hydrophilic cavity surfaces were successfully prepared by two methodologies: ' 1. Nanoporous polystyrenes fromPtBA-b-PS diblock or PDMS-b-PtBA-b-PS triblock copolymer precursors by atom transfer radical polymerization (ATRP), or combination...... of living anionic polymerization~ and ATRP r~spectively. The one, PtBA block, can be modified to the hydrophilic PAA, where the dther, polydimethysiloxane (PDMS) block, can be fully degraded. Deprotection of the tert-butyl groups in PtBA and the selective etching of PDMS· chains were accomplished...... by applying HF or TFA in one step. Thus both the di- and triblock copolymers after such a treatment resulted. in nanoporous polystyrenes with hexagonal cavities of different nanosizes (6-11 nm, Figure 1). 2. Nanoporous I,2-polybutadienes (I,2-PB) by grafting various acrylic monomers onto the pore. surfaces...

  5. 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...... are the components of the bi-disperse melt. The measurements show three separated relaxation regimes: a fast regime, a transition regime, and a slow regime. In the fast regime, the orientation of the long chains is frozen and the stress relaxation is due to stretch relaxation of the short chains primarily....... Conversely in the slow regime, the long chains have retracted and undergo relaxation of orientation in fully relaxed short chains....

  6. Polystyrene negative resist for high-resolution electron beam lithography

    Directory of Open Access Journals (Sweden)

    Ma Siqi

    2011-01-01

    Full Text Available Abstract We studied the exposure behavior of low molecular weight polystyrene as a negative tone electron beam lithography (EBL resist, with the goal of finding the ultimate achievable resolution. It demonstrated fairly well-defined patterning of a 20-nm period line array and a 15-nm period dot array, which are the densest patterns ever achieved using organic EBL resists. Such dense patterns can be achieved both at 20 and 5 keV beam energies using different developers. In addition to its ultra-high resolution capability, polystyrene is a simple and low-cost resist with easy process control and practically unlimited shelf life. It is also considerably more resistant to dry etching than PMMA. With a low sensitivity, it would find applications where negative resist is desired and throughput is not a major concern.

  7. Biodegradation of weathered polystyrene films in seawater microcosms

    OpenAIRE

    Syranidou, Evdokia; Karkanorachaki, Katerina; Amorotti, Filippo; Franchini, Martina; Repouskou, Eftychia; Kaliva, Maria; Vamvakaki, Maria; Kolvenbach, Boris; Fava, Fabio; Corvini, Philippe F.-X.; Kalogerakis, Nicolas

    2017-01-01

    A microcosm experiment was conducted at two phases in order to investigate the ability of indigenous consortia alone or bioaugmented to degrade weathered polystyrene (PS) films under simulated marine conditions. Viable populations were developed on PS surfaces in a time dependent way towards convergent biofilm communities, enriched with hydrocarbon and xenobiotics degradation genes. Members of Alphaproteobacteria and Gammaproteobacteria were highly enriched in the acclimated plastic associate...

  8. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... 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...

  9. Electrorheological Properties of Suspensions Prepared from Polystyrene- Block- Polyisoprene Copolymer

    OpenAIRE

    YAVUZ, Mustafa

    2014-01-01

    Considerable scientific and industrial interest is currently being focused on a class of materials known as electrorheological (ER) fluids, which display remarkable rheological behaviour, being able to convert rapidly and repeatedly from a liquid to solid when an electric field (E) is applied or removed. In this article, the synthesis, characterization, partial hydrolysis and ER properties of polystyrene- block}-polyisoprene copolymer (COP) were investigated. The block copolymer was ...

  10. Radiation effect on polystyrene deposited and grafted on silica gel

    International Nuclear Information System (INIS)

    Kusama, Y.; Udagawa, A.; Takehisa, M.

    1978-01-01

    The effect of radiation on polystyrene was studied in the presence and absence of silica gel by molecular weight measurement with gel permeation chromatography (GPC). Polystyrene crosslinked under vacuum in the absence of silica gel, but it either crosslinked or degraded by radiation, depending on the molecular weight of the polymer in the presence of silica gel. part of the deposited polymer bonded to silica gel by radiation; the G value for graft-chain formation is in the range of 0.01 to 0.1. Irradiation of polystyrene grafted on silica gel resulted in degradation of the graft chain because of the transfer of energy from silica gel. The G value for main chain scission was about 2 when graft polymer was irradiated in the absence of homopolymer. The degradation of graft polymer was suppressed when the polymer was irradiated in the presence of homopolymer, and the amount of unextractable polymer from silica gel increased with increasing irradiation. This adds evidence to the estimation that an increase in grafting percent coupled with a slight decrease in molecular weight at a later stage of radiation-induced polymerization of styrene adsorbed on slica gel is due to a secondary effect of radiation on the polymer

  11. Physical and Chemical Changes of Polystyrene Nanospheres Irradiated with Laser

    International Nuclear Information System (INIS)

    Mustafa, Mohd Ubaidillah; Juremi, Nor Rashidah Md.; Mohamad, Farizan; Wibawa, Pratama Jujur; Agam, Mohd Arif; Ali, Ahmad Hadi

    2011-01-01

    It has been reported that polymer resist such as PMMA (Poly(methyl methacrylate) which is a well known and commonly used polymer resist for fabrication of electronic devices can show zwitter characteristic due to over exposure to electron beam radiation. Overexposed PMMA tend to changes their molecular structure to either become negative or positive resist corresponded to electron beam irradiation doses. These characteristic was due to crosslinking and scissors of the PMMA molecular structures, but till now the understanding of crosslinking and scissors of the polymer resist molecular structure due to electron beam exposure were still unknown to researchers. Previously we have over exposed polystyrene nanospheres to various radiation sources, such as electron beam, solar radiation and laser, which is another compound that can act as polymer resist. We investigated the physical and chemical structures of the irradiated polystyrene nanospheres with FTIR analysis. It is found that the physical and chemical changes of the irradiated polystyrene were found to be corresponded with the radiation dosages. Later, combining Laser irradiation and Reactive Ion Etching manipulation, created a facile technique that we called as LARIEA NSL (Laser and Reactive Ion Etching Assisted Nanosphere Lithography) which can be a facile technique to fabricate controllable carbonaceous nanoparticles for applications such as lithographic mask, catalysts and heavy metal absorbers.

  12. Separation of transfer ribonucleic acids on polystyrene anion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, R.P.; Griffin, G.D.; Novelli, G.D.

    1976-11-16

    The transfer RNA separation by chromatography on strong-base-polystyrene exchange materials is examined and compared with the widely used reversed-phase chromatography. Results indicate important differences in some transfer RNA (tRNA) elution patterns by the anion-exchange chromatography, as compared with the reversed-phase chromatography. Transfer RNAs containing hydrophobic groups are adsorbed more strongly. The anion exchanger has twice the number of theoretical plates. Single peaks of tRNA/sub 2//sup Glu/ and tRNA/sub 1//sup Phe/ obtained from the reversed-phase column give multiple peaks on polystyrene anion-exchange chromatography. All six leucine tRNAs (Escherichia coli) and differences in tRNA populations synthesized during early and late stages of the dividing lymphocytes from normal human blood can be characterized by the anion-exchange chromatography. Different separation profiles are obtained by two separation systems for tyrosine tRNAs from mouse liver and mouse-plasma-cell tumor. The results indicate that, in contrast to the reversed-phase chromatography, strong-base-polystyrene anion-exchange chromatography is capable of separating tRNAs with minor structural differences.

  13. 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...

  14. Effect of molecular weight distribution on e-beam exposure properties of polystyrene

    International Nuclear Information System (INIS)

    Dey, Ripon Kumar; Cui Bo

    2013-01-01

    Polystyrene is a negative electron beam resist whose exposure properties can be tuned simply by using different molecular weights (Mw). Most previous studies have used monodisperse polystyrene with a polydispersity index (PDI) of less than 1.1 in order to avoid any uncertainties. Here we show that despite the fact that polystyrene’s sensitivity is inversely proportional to its Mw, no noticeable effect of very broad molecular weight distribution on sensitivity, contrast and achievable resolution is observed. It is thus unnecessary to use the costly monodisperse polystyrene for electron beam lithography. Since the polydispersity is unknown for general purpose polystyrene, we simulated a high PDI polystyrene by mixing in a 1:1 weight ratio two polystyrene samples with Mw of 170 and 900 kg mol −1 for the high Mw range, and 2.5 and 13 kg mol −1 for the low Mw range. The exposure property of the mixture resembles that of a monodisperse polystyrene with similar number averaged molecular weight (Mn)-bar, which indicates that it is (Mn)-bar rather than (Mw)-bar (weight averaged molecular weight) that dominates the exposure properties of polystyrene resist. This also implies that polystyrene of a certain molecular weight can be simulated by a mixture of two polystyrenes having different molecular weights. (paper)

  15. 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.

  16. 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.

  17. 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.

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

    KAUST Repository

    Li, Huawei; Fan, Yiqiang; Foulds, Ian G.; Kodzius, Rimantas

    2013-01-01

    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.

  19. 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...

  20. 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...

  1. 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.

  2. 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)

  3. Diameter measurements of polystyrene particles with atomic force microscopy

    International Nuclear Information System (INIS)

    Garnaes, J

    2011-01-01

    The size of (nano) particles is a key parameter used in controlling their function. The particle size is also important in order to understand their physical and chemical properties and regulate their number in health and safety issues. In this work, the geometric diameters of polystyrene spheres of nominal diameter 100 nm are measured using atomic force microscopy. The measurements are based on the apex height and on the average distance between neighbouring spheres when they form a close-packed monolayer on a flat mica substrate. The most important influence parameters for the determination of the geometric diameter are the lateral air gaps and deformation of the spheres. The lateral air gaps are caused by significant size variations of the individual spheres, and a correction is calculated based on the simulation of packing of spheres. The deformation of the spheres is caused mainly by capillary forces acting when they are in contact with each other or with the mica substrate. Based on calculated capillary forces and the literature values of the elastic properties of the polystyrene and mica, the deformation is estimated to be 2 nm with a standard uncertainty of 2 nm. The geometric diameter of the polystyrene spheres was measured with a combined standard uncertainty of ≈3 nm. The measured vertical diameter of 92.3 nm and the certified mobility equivalent diameter measured by differential mobility analysis (DMA) are marginally consistent at a confidence level of 95%. However, the measured lateral geometric diameter was 98.9 nm and is in good agreement with DMA

  4. Modelling of Convective Process of Water Desorption from Polystyrene

    International Nuclear Information System (INIS)

    Stakic, M.; Nikolic, A.

    2008-01-01

    This study presents a mathematical model developed to evaluate the influence of structural and operational factors on convective dehydration process (desorption of liquid phase from capillary-porous material), as well as the possibility to utilize this model for the case of water desorption from polystyrene cation resin CG-8. The model accounts for unsteady one-dimensional simultaneous heat and mass transfer between the gas (air) and the solid phase (resin). The identification of effective transport properties for the considered fixed bed of material (resin CG 8) is discussed. To this purpose available data from the literature are used. (author)

  5. Preparation of polystyrene microsphere with emulsion microencapsulation method

    International Nuclear Information System (INIS)

    Li Bo Zhang Lin; Zhang Zhganwen; You Dan; Wei Yun; Wang Chaoyang; Lin Bo; Shi Tao; Chu Qiaomei

    2003-01-01

    The preparation of hollow polystyrene microspheres that are used as inner shell of multi-shell plastic microspheres in the ICF experiments is focused on. The effects of surfactants, water-soluble polymer and electrolyte on the properties of resultant microspheres are studied. Based on these experiments, a fabricating procedure was established with which hollow microspheres were prepared with diameter about 150-3000 μm, wall thickness 0.8-15 μm and toughness Ra less than 4 nm. (authors)

  6. 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.

  7. Melt dispersion of thermoplastic polystyrene in polymer polyols

    OpenAIRE

    2009-01-01

    Polystyrene is dispersed into a polyol via a mechanical dispersion process. A stabilizer is present to stabilize the dispersed polymer particles. The stabilizer includes a copolymer of (1) from 10 to 70% by weight of a branched polyol which has a molecular weight of from 4000 to 20,000, from 0.2 to about 1.2 polymerizable ethylenically unsaturated groups per molecule and from about 3 to about 8 hydroxyl groups per molecule with (2) from 30 to 90% by weight of styrene or a mixture of styrene a...

  8. The Surface Imprinted Polystyrene Beads Prepared via Emulsion Templates

    Institute of Scientific and Technical Information of China (English)

    Guo Xiang CHENG; Guang Ling PEI; Ling Gang ZENG; Li Yong ZHANG; Chao LIU

    2004-01-01

    In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788), the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer, cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.

  9. Performance ratio hardness characteristics polystyrene-metal composite materials

    International Nuclear Information System (INIS)

    Klepikov, V.F.; Prokhorenko, E.M.; Lytvynenko, V.V.; Zakharchenko, A.A.; Hazhmuradov, M.A.

    2015-01-01

    The methods of measuring the hardness of layered polystyrene-metallic composite materials. It is proposed to use powder-like tungsten and powder-like steel as radiation-protective layer. A measurement of the hardness of composites of different composition, and given its dependence on the particle size and their form. The possibility of increasing the hardness of the composites reinforced with metallic additives. Radiation-protective characteristics were calculated for the studied species of composite materials. Influence of the quantitative composition of the metal components is studied on the change of the absorbed dose of gamma radiation

  10. Processing and characterization of Polystyrene/cornstarch/organophilic clay hybrids

    International Nuclear Information System (INIS)

    Oliveira, Carlos Ivan R. de; Amorim, Ywrrenan C.; Andrade, Cristina T. de

    2011-01-01

    Polystyrene/cornstarch composite blends with organophilic Cloisite 15A were prepared in an internal mixer in the presence of maleic anhydride (MA). The contents of clay were 1, 3 and 5%, based on the weight of the blend. The results obtained by X-ray diffraction revealed significant intercalation and exfoliation of clay particles within the polymeric moiety, which indicate increased interaction between the components of the nanocomposites. Thermogravimetric analysis results revealed the increase in thermal stability for the compatibilized blends in relation to the noncompatibilized PS/starch blends. The composites showed better thermal stability with increasing clay content. (author)

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

    KAUST Repository

    Fan, Yiqiang; Li, Huawei; Conchouso Gonzalez, David; Foulds, Ian G.

    2013-01-01

    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.

  12. 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.

  13. Mass Transport Through Carbon Nanotube-Polystyrene Bundles

    Science.gov (United States)

    Lin, Rongzhou; Tran, Tuan

    2016-05-01

    Carbon nanotubes have been widely used as test channels to study nanofluidic transport, which has been found to have distinctive properties compared to transport of fluids in macroscopic channels. A long-standing challenge in the study of mass transport through carbon nanotubes (CNTs) is the determination of flow enhancement. Various experimental investigations have been conducted to measure the flow rate through CNTs, mainly based on either vertically aligned CNT membranes or individual CNTs. Here, we proposed an alternative approach that can be used to quantify the mass transport through CNTs. This is a simple method relying on the use of carbon nanotube-polystyrene bundles, which are made of CNTs pulled out from a vertically aligned CNT array and glued together by polystyrene. We experimentally showed by using fluorescent tagging that the composite bundles allowed measureable and selective mass transport through CNTs. This type of composite bundle may be useful in various CNT research areas as they are simple to fabricate, less likely to form macroscopic cracks, and offer a high density of CNT pores while maintaining the aligned morphology of CNTs.

  14. 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...

  15. Low cost plastic scintillator by using commercial polystyrene

    International Nuclear Information System (INIS)

    Oktar, O.; Ari, G.; Guenduez, O.; Demirel, H.; Demirbas, A.

    2009-01-01

    Plastic scintillation detectors have been used in nuclear and high energy physics for many decades. Among their benefits are fast response, ease of manufacture and versatility. Their main drawbacks are radiation resistance and cost. Plastic Scintillators can be described as solid materials which contain organic fluorescent compounds dissolved within a polymer matri10. Transparent plastics commonly used for light scintillation are Polystyrene (or PS, poly-vinyl-benzene) and polyvinyl-toluene (or PVT, poly-methyl-styron). In this activity, preliminary studies for low cost plastic scintillator production by using commercial polystyrene pellets and extrusion method were aimed. For this purpose, PS blocks consist of commercial fluorescent dopant were prepared by an extruder in SANAEM. Molds suitable for extruder were designed and manufactured and optimum production parameters such as extrusion temperature profile, extrusion rate and pressure were obtained. Plastic blocks prepared were optically and mechanically tested and its response against various radioactive sources was measured.This study has shown that plastic scintillators imported can be produced in SANAEM domestically and be used for detection of radioactive materials within the country or border gates.

  16. Gamma radiation effects on the structure and properties of polystyrene

    International Nuclear Information System (INIS)

    Lima, Ivania Soares de

    1996-01-01

    Polystyrene is a linear thermoplastic with a molecular weight ranging from 130,000 to 300,000 g/mole. This polymer has wide industrial applications. In medicine it is used to manufacture medical supplies which can be sterilized by ionizing radiation. The sterilization of medical instruments by ionizing radiation was introduced in the 60's as an alternative method to the conventional treatment with ethylene oxide gas. Radiosterilization is now worldwide standard procedure, as it is cheaper and cleaner. Some polymers, however, may show some changes in their physical properties following irradiation. These changes are due to the prevailing crosslinking and main chain scission induced by the irradiation of the polymeric system. In the present work, Brazilian-made polystyrene Lustrex was irrigated with γ rays in the presence of air at room temperature. Under these conditions, the analysis of viscosimetric essays showed the prevalence of crosslinking effects at doses up to 25 kGy and of main scission effects at does from 25 to 200 kGy. Observed G values (number of events per 100 eV of absorbed energy) pointed to low degrees of both crosslinking (Gx ∼ 0.15) and main chain scission (Gs ∼ 0.09). Therefore, the minor changes in Lustrex's molecular structure induced by irradiation have not influenced significantly its mechanical, thermal, and optical properties. As a result, Lustrex can be used in applications involving radiation without the need to introduce radioprotective to the polymeric system. (author)

  17. 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.

  18. Synthesis of well-defined polystyrene macrophotoinitiators by ATRP

    International Nuclear Information System (INIS)

    Degirmenci, M.

    2004-01-01

    Macrophotointiators are polymers with a photoinitiator functionality at side chains or in the end or middle of the chain. these materials are of great scientific and technological interest because of their application in UV-curable coatings and as precursors for graft and block copolymers depending on the position of the photoinitiator moiety incorporated. Many macrophotoinitiators have been synthesized and their utilization in both applications have been studied. The major concern for their uses particulary in the latter application was related to the efficiency of functionalization, well-defined and predetermined structures, and low polydispersities. Obviously, if the all chains are not functionalized, upon irradiation non-funtionalized chains will not be activated and consequently remain as homopolymers in the system. In this study, new mono and bifunctional atom transfer radical polymerization (ATRP) initionars were synthesized by the condensation of 2-bromopropanoyl bromide with 2-hydroxy-2-methyl-1-phenyl propan-1-one (HMPP) and 2-hydroxy-1-(4-(2-hydroxyethoxy) phenyl)-2-methyl propan-1-one (HE-HMPP), respectively and characterized. The ATRP of styrene (St) in bulk at 110 degrees by means of these initiators in conjunction with a cuprous complex Cu(I) Br/bipyridine yields polystyrenes with photoactive alkoxy phenylketone groups. GPC, spectroscopic and photodegradation studies revealed that the initiation efficiency was quantitative and low-polydispersity polystyrenes with photoinitiator functionality in the end or middle of chain were obtained

  19. 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.

  20. 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...

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

    KAUST Repository

    Fan, Yiqiang; Li, Huawei; Foulds, Ian G.

    2011-01-01

    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

  2. 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

  3. 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

  4. 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.

  5. Non-aqueous retention measurement: ultrafiltration behaviour of polystyrene solutions and colloidal silver particles

    NARCIS (Netherlands)

    Beerlage, M.A.M.; Beerlage, M.A.M.; Heijnen, M.L.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.; Strathmann, H.

    1996-01-01

    The retention behaviour of polyimide ultrafiltration membranes was investigated using dilute solutions of polystyrene in ethyl acetate as test solutions. It is shown that flow-induced deformation of the polystyrene chains highly affects the membrane retention. This coil-stretch transition is not

  6. Foam supported sulfonated polystyrene as a new acidic material for catalytic reactions

    NARCIS (Netherlands)

    Ordomskiy, V.; Schouten, J.C.; Schaaf, van der J.; Nijhuis, T.A.

    2012-01-01

    Polystyrene was grafted on carbon foam with a melted polypropylene film predeposited on the surface. Polystyrene was subsequently sulfonated by chlorosulfonic acid. The effect of the temperature, time of grafting and concentration of radical initiator was studied. The materials were characterized by

  7. 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%.

  8. Integration of polystyrene microlenses with both convex and concave profiles in a polymer-based microfluidic system

    KAUST Repository

    Fan, Yiqiang; Li, Huawei; Foulds, Ian G.

    2013-01-01

    This paper reports a new technique of fabricating polystyrene microlenses with both convex and concave profiles that are integrated in polymer-based microfluidic system. The polystyrene microlenses, or microlens array, are fabricated using the free

  9. Elongational viscosity of narrow molar mass distribution polystyrene. A Bach, K. Almdal, H.K. Rasmussen and O. Hassager

    DEFF Research Database (Denmark)

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

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distributin polystyrene melts ......Transient and steady elongational viscosity has been measured for two narrow molar mass distributin polystyrene melts ...

  10. 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 We......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...... 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...

  11. Absence of molecular deuterium dissociation during room-temperature permeation into polystyrene ICF target shells

    International Nuclear Information System (INIS)

    Honig, A.; Alexander, N.; Fan, Q.; Gram, R.; Kim, H.

    1991-01-01

    Polystyrene microshells filled with deuterium and tritium gas are important target shells for inertially confined fusion (ICF) and are particularly promising for target containing spin-polarized hydrogens fuels. A currently active approach to the latter uses polarized D in HD, in a method which requires preservation of the high purity of the initially prepared HD (very low specified H 2 and D 2 concentrations). This would not be possible if dissociation should occur during permeation into the target shells. We have thus tested polystyrene shells using a novel method which employs very pure polystyrene shells using a novel method which employs very pure ortho-D 2 as the test gas. An upper limit of 6 x 10 -4 was deduced for the dissociation of D 2 upon room temperature permeation through an approximately 8 um wall of polystyrene, clearing the way for use of polystyrene target shells for ICF fusion experiments with spin-polarized hydrogens fuels. 19 refs., 1 fig

  12. Enhanced sensitivity of a microfabricated resonator using a graphene-polystyrene bilayer membrane

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Minhyuk; Lee, Eunho; Cho, Kilwon; Jeon, Sangmin, E-mail: jeons@postech.ac.kr [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang (Korea, Republic of)

    2014-08-18

    A graphene layer was synthesized using chemical vapor deposition methods and a polystyrene solution was spin-cast onto the graphene film. The graphene-polystyrene bilayer membrane was attached between the two tines of a microfabricated quartz tuning fork (QTF). The modulus of the graphene-polystyrene bilayer was measured to be twice that of a pristine polystyrene membrane. Exposure of the membrane-coated QTF to ethanol vapor decreased the resonance frequency of the microresonator. The bilayer membrane-coated QTF produced a frequency change that was three times the change obtained using a polystyrene membrane-coated QTF, with a lower degree of degradation in the Q factor. The limit of detection of the bilayer membrane-coated QTF to ethanol vapor was determined to be 20 ppm.

  13. Polyvinyl alcohol coating of polystyrene inertial confinement fusion targets

    International Nuclear Information System (INIS)

    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 μm) on the target (outside diameter approx.350--850 μm). Thicker coatings are obtained by repeated applications of the coating solution. Preliminary results indicate that uniform coatings may be achievable on the targets with a background surface smoothness in the order of 1000 A

  14. Room temperature synthesis of water-repellent polystyrene nanocomposite coating

    International Nuclear Information System (INIS)

    Guo Yonggang; Jiang Dong; Zhang Xia; Zhang Zhijun; Wang Qihua

    2010-01-01

    A stable superhydrophobic polystyrene nanocomposite coating was fabricated by means of a very simple and easy method. The coating was characterized by scanning electron microscopy and X-ray photoelectron spectrum. The wettability of the products was also investigated. By adding the surface-modified SiO 2 nanoparticles, the wettability of the coating changed to water-repellent superhydrophobic, not only for pure water, but also for a wide pH range of corrosive liquids. The influence of the drying temperature and SiO 2 content on the wettability of the nanocomposite coating was also investigated. It was found that both factors had little or no significant effect on the wetting behavior of the coating surface.

  15. 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.

  16. Hydrodynamic chromatography of polystyrene microparticles in micropillar array columns.

    Science.gov (United States)

    Op de Beeck, Jeff; De Malsche, Wim; Vangelooven, Joris; Gardeniers, Han; Desmet, Gert

    2010-09-24

    We report on the possibility to perform HDC in micropillar array columns and the potential advantages of such a system. The HDC performance of a pillar array column with pillar diameter = 5 microm and an interpillar distance of 2.5 microm has been characterized using both a low MW tracer (FITC) and differently sized polystyrene bead samples (100, 200 and 500 nm). The reduced plate height curves that were obtained for the different investigated markers all overlapped very well, and attained a minimum value of about h(min)=0.3 (reduction based on the pillar diameter), corresponding to 1.6 microm in absolute value and giving good prospects for high efficiency separations. The obtained reduced retention time values were in fair agreement with that predicted by the Di Marzio and Guttman model for a flow between flat plates, using the minimal interpillar distance as characteristic interplate distance. Copyright 2010 Elsevier B.V. All rights reserved.

  17. Fabrication of oriented wrinkles on polydopamine/polystyrene bilayer films.

    Science.gov (United States)

    Wang, Rong; Long, Yuhua; Zhu, Tang; Guo, Jing; Cai, Chao; Zhao, Ning; Xu, Jian

    2017-07-15

    Wrinkles exist widely in nature and our life. In this paper, wrinkles on polydopamine (PDA)/polystyrene (PS) bilayer films were formed by thermal annealing due to the different thermal coefficients of expansion of each layer. The factors that influenced the dimensions of wrinkles were studied. We found that oriented wrinkles could be formed if the bilayer films were patterned with micro-grooves, and the degree of the orientation depended on the thickness of the PDA and the dimensions of the grooves. Combined with the strong adhesion, biocompatibility and reactivity of PDA, the oriented wrinkles on PDA/PS patterned bilayers may find potential application in diffraction gratings, optical sensors and microfluidic devices. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. 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.

  19. Adsorption of different amphiphilic molecules onto polystyrene latices.

    Science.gov (United States)

    Jódar-Reyes, A B; Ortega-Vinuesa, J L; Martín-Rodríguez, A

    2005-02-15

    In order to know the influence of the surface characteristics and the chain properties on the adsorption of amphiphilic molecules onto polystyrene latex, a set of experiments to study the adsorption of ionic surfactants, nonionic surfactants and an amphiphilic synthetic peptide on different latex dispersions was performed. The adsorbed amount versus the equilibrium surfactant concentration was determined. The main adsorption mechanism was the hydrophobic attraction between the nonpolar tail of the molecule and the hydrophobic regions of the latex surface. This attraction overcame the electrostatic repulsion between chains and latex surface with identical charge sign. However, the electrostatic interactions chain-surface and chain-chain also played a role. General patterns for the adsorption of ionic chains on charged latex surfaces could be established. Regarding the shape, the isotherms presented different plateaus corresponding to electrostatic effects and conformational changes. The surfactant size also affects the adsorption results: the higher the hydrophilic moiety in the surfactant molecule the lower the adsorbed amount.

  20. Preparation of magnetic nanoparticles embedded in polystyrene microspheres

    International Nuclear Information System (INIS)

    Nguyen Hoang Hai; Nguyen Hoang Luong; Nguyen Chau; Ngo Quy Tai

    2009-01-01

    Superparamagnetic particles are widely used for biological applications such as cell separation. The size of the particles is normally in the range of 10 - 20 nm which is much smaller than the size of a cell. Therefore small particles create small force which is not strong enough to separate the cells from solution. Superparamagnetic nanoparticles embedded in Polystyrene microspheres (magnetic beads) are very useful for cell separation. Magnetic beads have been prepared by solvent evaporation of an emulsion. The beads with size of 0.2 μm - 1.0 μm have a saturation magnetization of 10 - 25 emu/g. The change of the amount of surfactants, volatile solvent, magnetic particles resulted to the change of size, magnetic properties of the magnetic beads.

  1. 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.

  2. Biodegradation of weathered polystyrene films in seawater microcosms.

    Science.gov (United States)

    Syranidou, Evdokia; Karkanorachaki, Katerina; Amorotti, Filippo; Franchini, Martina; Repouskou, Eftychia; Kaliva, Maria; Vamvakaki, Maria; Kolvenbach, Boris; Fava, Fabio; Corvini, Philippe F-X; Kalogerakis, Nicolas

    2017-12-21

    A microcosm experiment was conducted at two phases in order to investigate the ability of indigenous consortia alone or bioaugmented to degrade weathered polystyrene (PS) films under simulated marine conditions. Viable populations were developed on PS surfaces in a time dependent way towards convergent biofilm communities, enriched with hydrocarbon and xenobiotics degradation genes. Members of Alphaproteobacteria and Gammaproteobacteria were highly enriched in the acclimated plastic associated assemblages while the abundance of plastic associated genera was significantly increased in the acclimated indigenous communities. Both tailored consortia efficiently reduced the weight of PS films. Concerning the molecular weight distribution, a decrease in the number-average molecular weight of films subjected to microbial treatment was observed. Moreover, alteration in the intensity of functional groups was noticed with Fourier transform infrared spectrophotometry (FTIR) along with signs of bio-erosion on the PS surface. The results suggest that acclimated marine populations are capable of degrading weathered PS pieces.

  3. Thermomechanical properties of the silanized-kenaf/polystyrene composites

    Directory of Open Access Journals (Sweden)

    2009-10-01

    Full Text Available In order to improve the poor interfacial adhesion of the kenaf fiber and polystyrene (PS in their composite material, the surface of the kenaf fiber was modified using a synthesized polymeric coupling agent to promote adhesion with PS matrix. The dynamic thermo-mechanical properties of the composite composed of modified kenaf fiber and PS were also investigated. The polymeric coupling agent treatment of the kenaf fiber increased the fiber-matrix interaction through a condensation reaction between alkoxysilane and hydroxyl groups of kenaf cellulose. DMA (Dynamic Mechanical Thermal Analysis results showed that the modified fiber composites have higher E′ and lower tanδ than those with untreated fiber indicating that a greater interfacial interaction between the matrix resin and the fiber. It was also found that the storage modulus increases in proportion with the Si/C ratio on the fiber surface.

  4. Evaluation of Recycling Polystyrene (PS) from a Microbiology Product

    OpenAIRE

    Eklöf, Jonas

    2014-01-01

    Detta är ett beställningsarbete av Plastone Oy och i det undersöks möjligheterna vad man kan göra genom återvinning med avfallsmaterialet som uppstår då man tillverkar en mikrobiologisk produkt i deras plastfabrik. Produkten tillverkas genom formsprutning och materialet som används är polystyren (PS). Ur litteraturstudien fann man varierande möjligheter på hur man kan återvinna PS på bästa sätt, men ingen lösning som har varit effektiv i praktiken. Det framgick också att återvunnet PS inte är...

  5. 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......-empirical model. The results show that the formation of co-continuous morphology strongly depends on blend composition and melt blending method, whereas the model prediction for phase inversion deviates from the experimental values. Further, we found that the initial mechanism of morphology evolution involves...... scanning electron microscopy (SEM) Co examine nine blend compositions. Blends were prepared at compositions where phase inversion was expected to occur according to model predictions. The experimental results were compared to the values of the point of phase inversion calculated with the semi...

  6. 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...... polymer in the other. The observed solubility strongly depends on blend composition and blending method. The T-g measurements showed maximum mutual solubility around 50/50 composition. The miscibility of PC/PS blended after the third stage (melt injection molding) was higher than that after the first...... by measuring their glass transition temperatures (T-g) and their specific heat increment (DeltaC(p)). Differential scanning calorimetry (DSC) was used to examine nine blend compositions. Shifts in glass transition temperature (T-g) of the two phases in melt-mixed PC/PS blends suggest partial miscibility of one...

  7. Photoacoustic monitoring of inhomogeneous curing processes in polystyrene emulsions

    International Nuclear Information System (INIS)

    Vargas-Luna, M.; Gutierrez-Juarez, G.; Rodriguez-Vizcaino, J.M.; Varela-Nsjera, J.B.; Rodriguez-Palencia, J.M.; Bernal-Alvarado, J.; Sosa, M.; Alvarado-Gil, J.J.

    2002-01-01

    The time evolution of the inhomogeneous curing process of polystyrene emulsions is studied using a variant of the conventional photoacoustic (PA) technique. The thermal effusivity, as a function of time, is determined in order to monitor the sintering process of a styrene emulsion in different steps of the manufacturing procedure. PA measurements of thermal effusivity show a sigmoidal growth as a function of time during the curing process. The parameterization of these curves permits the determination of the characteristic curing time and velocity of the process. A decreasing of the curing time and an increasing curing velocity for the final steps of the manufacturing process are observed. The feasibility of our approach and its potentiality for the characterization of other curing process are discussed. (author)

  8. Glass transition and thermal expansivity of polystyrene thin films

    International Nuclear Information System (INIS)

    Inoue, R.; Kanaya, T.; Miyazaki, T.; Nishida, K.; Tsukushi, I.; Shibata, K.

    2006-01-01

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T g and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements

  9. Glass transition and thermal expansivity of polystyrene thin films

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, R. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Kanaya, T. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan)]. E-mail: kanaya@scl.kyoto-u.ac.jp; Miyazaki, T. [Nitto Denko Corporation, 1-1-2 Shimohozumi, Ibaraki, Osaka-fu 567-8680 (Japan); Nishida, K. [Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011 (Japan); Tsukushi, I. [Chiba Institute of Technology, Narashino, Chiba-ken 275-0023 (Japan); Shibata, K. [Japan Atomic Energy Research Institute, Tokai, Ibaraki-ken 319-1195 (Japan)

    2006-12-20

    We have studied glass transition temperature and thermal expansivity of polystyrene thin films supported on silicon substrate using X-ray reflectivity and inelastic neutron scattering techniques. In annealing experiments, we have found that the reported apparent negative expansivity of polymer thin films is caused by unrelaxed structure due to insufficient annealing. Using well-annealed films, we have evaluated glass transition temperature T {sub g} and thermal expansivity as a function of film thickness. The glass transition temperature decreases with film thickness and is constant below about 10 nm, suggesting the surface glass transition temperature of 355 K, which is lower than that in bulk. We have also found that the thermal expansivity in the glassy state decreases with film thickness even after annealing. The decrease has been attributed to hardening of harmonic force constant arising from chain confinement in a thin film. This idea has been confirmed in the inelastic neutron scattering measurements.

  10. Nanostructured magnetic particles with polystyrene and their magnetorheological applications.

    Science.gov (United States)

    Fang, Fei Fei; Choi, Hyoung Jin

    2011-03-01

    Magnetorheological (MR) fluids are known to be colloidal suspensions of magnetic particles in a non-magnetic fluid, and exposure to a magnetic field transforms the fluid into a plastic-like solid in milliseconds. To improve the stability against sedimentation and uniform dispersion, two different MR candidates, soft magnetic carbonyl iron (CI) microspheres and magnetite (Fe3O4) particles were modified with polystyrene to be applied for MR fluids in this study. After modification, their unique morphology, crystalline structure and magnetic properties were examined in addition to MR performance and sedimentation characteristics. It was found that this embedded morphology not only effectively prevents direct contact of the magnetic species thus improving particle dispersion but also leads to obvious change in their density, compared with the traditional polymer coating method with a core-shell structure.

  11. Influence of entanglements on glass transition temperature of polystyrene

    Science.gov (United States)

    Ougizawa, Toshiaki; Kinugasa, Yoshinori

    2013-03-01

    Chain entanglement is essential behavior of polymeric molecules and it seems to affect many physical properties such as not only viscosity of melt state but also glass transition temperature (Tg). But we have not attained the quantitative estimation because the entanglement density is considered as an intrinsic value of the polymer at melt state depending on the chemical structure. Freeze-drying method is known as one of the few ways to make different entanglement density sample from dilute solution. In this study, the influence of entanglements on Tg of polystyrene obtained by the freeze-dried method was estimated quantitatively. The freeze-dried samples showed Tg depression with decreasing the concentration of precursor solution due to the lower entanglement density and their depressed Tg would be saturated when the almost no intermolecular entanglement was formed. The molecular weight dependence of the maximum value of Tg depression was discussed.

  12. 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.

  13. 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.

  14. Conversion of Hazardous Motor Vehicle Used Tire and Polystyrene Waste Plastic Mixture into useful Chemical Products

    OpenAIRE

    Moinuddin Sarker; Mohammad Mamunor Rashid

    2014-01-01

    Motor vehicle used tire and polystyrene waste plastic mixture into fuel recovery using thermal degradation process in laboratory batch process. Motor vehicle used tire and polystyrene waste plastic was use 75 gm by weight. Motor vehicle tire was 25 gm and polystyrene waste plastic was 50 gm. In presence of oxygen experiment was performed under laboratory fume hood. Thermal degradation temperature range was 100 - 420 oC and experiment run time was 5 hours. Product fuel density is 0.84 gm/ml an...

  15. 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.

  16. AFM-based force spectroscopy on polystyrene brushes: effect of brush thickness on protein adsorption.

    Science.gov (United States)

    Hentschel, Carsten; Wagner, Hendrik; Smiatek, Jens; Heuer, Andreas; Fuchs, Harald; Zhang, Xi; Studer, Armido; Chi, Lifeng

    2013-02-12

    Herein we present a study on nonspecific binding of proteins at highly dense packed hydrophobic polystyrene brushes. In this context, an atomic force microscopy tip was functionalized with concanavalin A to perform single-molecule force spectroscopy measurements on polystyrene brushes with thicknesses of 10 and 60 nm, respectively. Polystyrene brushes with thickness of 10 nm show an almost two times stronger protein adsorption than brushes with a thickness of 60 nm: 72 pN for the thinner and 38 pN for the thicker layer, which is in qualitative agreement with protein adsorption studies conducted macroscopically by fluorescence microscopy.

  17. 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.

  18. Preparation of tritiated polystyrene and its application in radio luminescent paints

    International Nuclear Information System (INIS)

    Ravi, S.; Mathewy, K.M.; Seshadri, N.K.; Subramanian, T.K.

    2001-01-01

    Beta radiation emanating from tritiated polystyrene in close proximity with copper activated zinc sulphide phosphor will provide self-sustained light sources and are used for nocturnal illumination of watches and clocks, product advertisements, telephone numbers, exit signs etc. Phenylacetylene was partially reduced in diethyl ether medium with tritium using 5% Pd/C poisoned with quinoline to give styrene. Styrene formed was polymerised to polystyrene by subjecting it to irradiation with γ-radiation (20 mega rad dose). Copper activated zinc sulphide phosphor was coated with tritiated polystyrene to give self-sustained light sources. (author)

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

    International Nuclear Information System (INIS)

    Sun Changmei; Zhang Shuanhong; Qu Rongjun; Sun Tao; Zhang Ying; Zhang Xiang; Song Jingyang

    2010-01-01

    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 2 ) and poly(p-aminostyrene)-coated silica (SG-PS-NH 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.

  20. 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.

  1. Production low cost plastic scintillator by using commercial polystyrene

    International Nuclear Information System (INIS)

    2011-01-01

    Plastic Scintillators can be described as solid materials which contain organic fluorescent compounds dissolved within a polymer matrix. Transparent plastics commonly used for light scintillation are Polystyrene (or PS, poly-vinyl-benzene) and polyvinyl-toluene (or PVT, poly-methyl-styron). By changing the composition of plastic Scintillators some features such as light yield, radiation hardening, decay time etc. can be controlled. Plastic scintillation detectors have been used in nuclear and high energy physics for many decades. Among their benefits are fast response, ease of manufacture and versatility. Their main drawbacks are radiation resistance and cost. Many research projects have concentrated on improving the fundamental properties of plastic scintillators, but little attention has focussed on their cost and easier manufacturing techniques. First plastic Scintillators were produced in 1950's. Activities for production of low cost Scintillators accelerated in second half of 1970's. In 1975 acrylic based Plexipop Scintillator was developed. Despite its low cost, since its structure was not aromatic the light yield of Plexipop was about one quarter of classical Scintillators. Problems arising from slow response time and weak mechanical properties in scintillators developed, has not been solved until 1980. Within the last decade extrusion method became very popular in preparation of low cost and high quality plastic scintillators. In this activity, preliminary studies for low cost plastic scintillator production by using commercial polystyrene pellets and extrusion plus compression method were aimed. For this purpose, PS blocks consist of commercial fluorescent dopant were prepared in June 2008 by use of the extruder and pres in SANAEM. Molds suitable for accoupling to extruder were designed and manufactured and optimum production parameters such as extrusion temperature profile, extrusion rate and moulding pressure were obtained hence, PS Scintillator Blocks

  2. Micellar aggregates of amylose-block-polystyrene rod-coil block copolymers in water and THF

    NARCIS (Netherlands)

    Loos, Katja; Böker, Alexander; Zettl, Heiko; Zhang, Mingfu; Krausch, Georg; Müller, Axel H.E.; Boker, A.; Zhang, A.F.

    2005-01-01

    Amylose-block-polystyrenes with various block copolymer compositions were investigated in water and in THF solution. Fluorescence correlation spectroscopy, dynamic light, scattering (DLS), and asymmetric flow field-flow fractionation with multiangle light scattering detection indicate the presence

  3. Microscopy evidence of the face-centered cubic arrangement of monodisperse polystyrene nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Hui [School of Science, Beijing Jiaotong University, Beijing 100044 (China)]. E-mail: zhanghui14305@sohu.com; Duan Renguan [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Li Fan [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Tang Qing [Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Li Wenchao [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2007-07-01

    This paper reports a scanning electron microscopy (SEM) investigation of polystyrene artificial opal achieved through self-assembly of monodisperse polystyrene nanospheres with a diameter of 250 nm from colloidal suspension after being ambient dried. A detailed analysis of the SEM images verifies that the face-centered cubic (fcc) phase is the most stable one for the polystyrene opal prepared. This finding provides a strong support for, by using polystyrene opal as template, fabricating a photonic crystal with inverse fcc structure of full band gap if the refractive index contrast is higher than 2.8 and the filling fraction of the high index materials is between 0.2 and 0.3.

  4. Microscopy evidence of the face-centered cubic arrangement of monodisperse polystyrene nanospheres

    International Nuclear Information System (INIS)

    Zhang Hui; Duan Renguan; Li Fan; Tang Qing; Li Wenchao

    2007-01-01

    This paper reports a scanning electron microscopy (SEM) investigation of polystyrene artificial opal achieved through self-assembly of monodisperse polystyrene nanospheres with a diameter of 250 nm from colloidal suspension after being ambient dried. A detailed analysis of the SEM images verifies that the face-centered cubic (fcc) phase is the most stable one for the polystyrene opal prepared. This finding provides a strong support for, by using polystyrene opal as template, fabricating a photonic crystal with inverse fcc structure of full band gap if the refractive index contrast is higher than 2.8 and the filling fraction of the high index materials is between 0.2 and 0.3

  5. 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.

  6. Application of polystyrene - water calorimeter in determination of absorbed dose. Vol. 4.

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, F A [Nuclear Materials Authority, Maadi, Cairo (Egypt); Ashry, H A; El-Behay, A Z; Abdou, S [National Center, for Radiation Research and Technology, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The polystyrene-water calorimeter was investigated as a modification of the water calorimeter, where the polystyrene has a low specific heat and negligible known heat defect. This calorimeter was designed, constructed and calibrated for measurement of radiation absorbed dose. The system utilizes a thermistor to detect the radiation-induced temperature rise in the polystyrene absorber at certain point from the radiation source. A temperature stability of as low as 0.0018 degree C/min in a 42.0 degree C environment, and a gamma-radiation sensitivity of as high as 1.9720 ohm/Gy were obtained. Comparisons of the results obtained by using the polystyrene-water calorimeter with those obtained by applying other types of calorimeters i.e., water and graphite calorimeters were also done to aid in the possible realization of an accurate and efficient instrument for use under widely different irradiation conditions. 4 figs., 1 tab.

  7. Thermo-mechanical properties of polystyrene-based shape memory nanocomposites

    NARCIS (Netherlands)

    Xu, B.; Fu, Y.Q.; Ahmad, M.; Luo, J.K.; Huang, W.M.; Kraft, A.; Reuben, R.; Pei, Y.T.; Chen, Zhenguo; Hosson, J.Th.M. De

    2010-01-01

    Shape memory nanocomposites were fabricated using chemically cross-linked polystyrene (PS) copolymer as a matrix and different nanofillers (including alumina, silica and clay) as the reinforcing agents. Their thermo-mechanical properties and shape memory effects were characterized. Experimental

  8. Effect of acid treated carbon nanotubes on mechanical, rheological and thermal properties of polystyrene nanocomposites

    KAUST Repository

    Amr, Issam Thaher; Al-Amer, Adnan M J; Selvin, Thomas P.; Al-Harthi, Mamdouh Ahmed; Girei, Salihu Adamu; Sougrat, Rachid; Atieh, Muataz Ali

    2011-01-01

    In this work, multiwall carbon nanotubes (CNT) were functionalized by acid treatment and characterized using Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Polystyrene/CNT composites of both the untreated

  9. 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.

  10. A reactive polystyrene-block-polyisoprene star copolymer as a toughening agent in an epoxy thermoset

    KAUST Repository

    Francis, Raju; Baby, Deepa K.

    2015-01-01

    © 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

  11. Polystyrene microplastics induce microbiota dysbiosis and inflammation in the gut of adult zebrafish.

    Science.gov (United States)

    Jin, Yuanxiang; Xia, Jizhou; Pan, Zihong; Yang, Jiajing; Wang, Wenchao; Fu, Zhengwei

    2018-04-01

    Microplastic (MP) are environmental pollutants and have the potential to cause varying degrees of aquatic toxicity. In this study, the effects on gut microbiota of adult male zebrafish exposed for 14 days to 100 and 1000 μg/L of two sizes of polystyrene MP were evaluated. Both 0.5 and 50 μm-diameter spherical polystyrene MP increased the volume of mucus in the gut at a concentration of 1000 μg/L (about 1.456 × 10 10 particles/L for 0.5 μm and 1.456 × 10 4 particles/L for 50 μm). At the phylum level, the abundance of Bacteroidetes and Proteobacteria decreased significantly and the abundance of Firmicutes increased significantly in the gut after 14-day exposure to 1000 μg/L of both sizes of polystyrene MP. In addition, high throughput sequencing of the 16S rRNA gene V3-V4 region revealed a significant change in the richness and diversity of microbiota in the gut of polystyrene MP-exposed zebrafish. A more in depth analysis, at the genus level, revealed that a total of 29 gut microbes identified by operational taxonomic unit (OTU) analysis were significantly changed in both 0.5 and 50 μm-diameter polystyrene MP-treated groups. Moreover, it was observed that 0.5 μm polystyrene MP not only increased mRNA levels of IL1α, IL1β and IFN but also their protein levels in the gut, indicating that inflammation occurred after polystyrene MP exposure. Our findings suggest that polystyrene MP could induce microbiota dysbiosis and inflammation in the gut of adult zebrafish. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Solvent effect on polystyrene surface roughness on top of QCM sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sakti, Setyawan P., E-mail: sakti@ub.ac.id; Rahmawati, Eka; Robiandi, Fadli [Advanced System and Material Technology, Laboratory of Instrumentation and Measurement Department of Physics, Brawijaya University (Indonesia)

    2016-03-11

    Quartz Crystal Microbalance (QCM) has been used as a basis for many chemical sensors and biosensor. Its sensitivity to mass change which can detect a mass change on its surface down to sub ng/cm2 is one of its interesting aspects. Another interesting feature is its ability to work in liquid environment. However, there are many aspects which influence QCM sensor properties in contact with liquid. One of the aspects is surface roughness of the matrix layer where on top of it a biological sensitive layer will be immobilized. One of matrix layers in the immobilizing biological sensitive layer was polystyrene. Polystyrene was coated on the QCM sensor by using the spin coating method. During the coating process, polystyrene was solved using non-polar solvent. It is known that the physical and chemical properties of the solvent affect a transition process from soluble polymer becoming rigid polymer layer. In this work, we show that polystyrene solved in chloroform has a higher surface roughness compare to one solved in toluene, xylene, or tetrahydrofuran. Surface roughness of the polystyrene coating were measured using a non-contact profilometer. However, we also found that there is no difference on the electrical impedance of the QCM sensor coated with polystyrene resulted from differing solvent when the sensor was in contact with air and water. Thus, all of the mentioned solvent can be used to solve the polystyrene as a coating material for QCM sensor without affecting the electrical performance of the sensor, but the choice of the solution can be used as a simple method to control the difference roughness of the polystyrene coating.

  13. 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.

  14. Coarse graining of atactic polystyrene and its derivatives

    Science.gov (United States)

    Agrawal, Anupriya; Perahia, Dvora; Grest, Gary S.

    2014-03-01

    Capturing large length scales in polymers and soft matter while retaining atomistic properties is imperative to computational studies of dynamic systems. Here we present a new methodology developing coarse-grain model based on atomistic simulation of atactic polystyrene (PS). Similar to previous work by Fritz et al., each monomer is described by two coarse grained beads. In contrast to this earlier work where intramolecular potentials were based on Monte Carlo simulation of both isotactic and syndiotactic single PS molecule to capture stereochemistry, we obtained intramolecular interactions from a single molecular dynamics simulation of an all-atom atactic PS melts. The non-bonded interactions are obtained using the iterative Boltzmann inversion (IBI) scheme. This methodology has been extended to coarse graining of poly-(t-butyl-styrene) (PtBS). An additional coarse-grained bead is used to describe the t-butyl group. Similar to the process for PS, the intramolecular interactions are obtained from a single all atom atactic melt simulation. Starting from the non-bonded interactions for PS, we show that the IBI method for the non-bonded interactions of PtBS converges relatively fast. A generalized scheme for substituted PS is currently in development. We would like to acknowledge Prof. Kurt Kremer for helpful discussions during this work.

  15. Indentation deformation and fracture of thin polystyrene films

    International Nuclear Information System (INIS)

    Li Min; Palacio, Manuel L.; Barry Carter, C.; Gerberich, William W.

    2002-01-01

    Nanoindentation-induced deformation and fracture of thin polystyrene (PS) films on glass substrates were characterized using visible-light microscopy and atomic force microscopy (AFM). Two film thicknesses, 2 and 3.5 μm were studied. It was difficult to induce delamination in the 2-μm film while the 3.5-μm film delaminated easily under indentation loads of 150 mN and higher. AFM cross-section analysis of the deformation and fracture geometry revealed that the ratio of the delamination radius to contact radius was between 3 and 4. Analysis of the fracture surface on the glass side indicates that substrate cracking acts as a trigger for initiation and propagation of interfacial cracks. Crack-arrest marks and process-zone marks were also observed by AFM imaging. The interfacial fracture toughness, or practical work of adhesion, was evaluated following two methods based on the indentation-induced delamination and a process-zone analysis. The fracture toughness was found to be approximately 0.6 J/m 2 for the 3.5-μm PS film on glass. AFM examination of the glass surface after indentation also showed fine flow lines around the indentation impression, indicating plastic deformation of glass

  16. Indentation deformation and fracture of thin polystyrene films

    Energy Technology Data Exchange (ETDEWEB)

    Li Min; Palacio, Manuel L.; Barry Carter, C.; Gerberich, William W

    2002-09-02

    Nanoindentation-induced deformation and fracture of thin polystyrene (PS) films on glass substrates were characterized using visible-light microscopy and atomic force microscopy (AFM). Two film thicknesses, 2 and 3.5 {mu}m were studied. It was difficult to induce delamination in the 2-{mu}m film while the 3.5-{mu}m film delaminated easily under indentation loads of 150 mN and higher. AFM cross-section analysis of the deformation and fracture geometry revealed that the ratio of the delamination radius to contact radius was between 3 and 4. Analysis of the fracture surface on the glass side indicates that substrate cracking acts as a trigger for initiation and propagation of interfacial cracks. Crack-arrest marks and process-zone marks were also observed by AFM imaging. The interfacial fracture toughness, or practical work of adhesion, was evaluated following two methods based on the indentation-induced delamination and a process-zone analysis. The fracture toughness was found to be approximately 0.6 J/m{sup 2} for the 3.5-{mu}m PS film on glass. AFM examination of the glass surface after indentation also showed fine flow lines around the indentation impression, indicating plastic deformation of glass.

  17. Positron states in polypropylene and polystyrene at low temperature

    International Nuclear Information System (INIS)

    Djourelov, N.; Dauwe, C.; Palacio, C.A.; Laforest, N.; Bas, C.

    2007-01-01

    The increase of the positronium (Ps) yield as a function of the positron (e + ) source exposure time at 20 K was monitored in polypropylene and polystyrene by positron annihilation lifetime (PAL) and Doppler broadening (DB) spectroscopy. The contributions of the different e + and Ps states as extracted from the PAL analysis were used to reproduce the behaviour of the sharpness parameter (S) as a function of the wing parameter (W) of the annihilation line as measured by DB spectroscopy. We find a remarkable non-linearity in the S -W plots, which seems to be related to the existence of a third component (C 3 ) in a four-component exponential analysis. We discuss the origin of C 3 in the frame of a ''blob'' analysis of the PAL spectra. It is shown that the simulated S-W dependence can satisfactorily fit the observed non-linearity only on the assumption that C 3 characterizes a e + -molecule complex. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Radioluminescence of aromatic molecule solutions in atactic and isotactic polystyrene

    International Nuclear Information System (INIS)

    Lisovskaya, I.A.; Alfimov, M.V.; Milinchuk, V.K.; Skvortsov, V.G.

    1975-01-01

    The generation of excited states of naphthalene-d 8 and carbazole molecules in polystyrene (PS) under X-ray illumination was investigated using luminescence method. A comparison of the concentration dependences of radioluminescence of the aromatic additives to solid PS and to toluene as well as the pattern of concentration versus photoluminescence of naphthalene-d 8 in PS demonstrates that unlike toluene there is no singlet-triplet conversion in PS owing to the formation of excimers. It is shown that the excited ststes of the aromatic additives in PS are populated under radiolysis via an energy transfer from singlet to triplet molecules of the matrix. Under the radiolysis the excited states of PS molecules may generate upon charge recombination. A comparison of radio luminescence spectra of the corresponding aromatic additives in two isomeric PS structures (atacting and isotactic) shows different processes with charge participation. The difference detected in the radioluminescence spectra of aromatic additives in the atactic and isotactic PS explained by the greater number of defects in atactic PS competing with the polymer molecule ion for charge capture

  19. The preparation of 125I labelled sodium polystyrene sulphonate

    International Nuclear Information System (INIS)

    Harrison, I.; Higgo, J.J.W.; Williams, G.M.

    1992-01-01

    A radio-labelled polymeric colloid for use in field studies of colloidal migration was prepared. Sodium polystyrene p-sulphonate (PSSNa) with an average molecular weight of 500,000 Daltons was labelled with iodine 125. The report describes the preparation, purification and characterisation of this material. In order to use a standard technique for radio-iodination, by the iodinium ion, a very small number of phenolic groups had to be introduced into the polymer initially. This was done by a carefully controlled reaction with sodium hydroxide optimised so that a qualitative test for p-phenols gave a discernible positive result yet size exclusion chromatography indicated that no noticeable change in bulk properties of the PSSNa had occurred. The modified PSSNa was radio-iodinated and size exclusion chromatography was used to quantify the yield, activity and stability of the product. The radio-iodination of a bulk sample of the modified PSSNa was entrusted to Amersham who prepared a labelled product with an activity of 1.12 MBq per mg PSSNa. The mobility of this material was studied in the laboratory using spike injections onto columns of Drigg sand, sieved and unsieved, eluted with Drigg groundwater. The results indicated that transport of PSSNa in the field should give information on the structure of flow paths in the Drigg aquifer. (Author)

  20. Composite plasma polymerized sulfonated polystyrene membrane for PEMFC

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

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

  1. The Evolution of Polystyrene as a Cell Culture Material.

    Science.gov (United States)

    Lerman, Max J; Lembong, Josephine; Muramoto, Shin; Gillen, Greg; Fisher, John P

    2018-04-10

    Polystyrene (PS) has brought in vitro cell culture from its humble beginnings to the modern era, propelling dozens of research fields along the way. This review discusses the development of the material, fabrication, and treatment approaches to create the culture material. However, native PS surfaces poorly facilitate cell adhesion and growthin vitro. To overcome this, liquid surface deposition, energetic plasma activation, and emerging functionalization methods transform the surface chemistry. This review seeks to highlight the many potential applications of the first widely accepted polymer growth surface. Although the majority of in vitro research occurs on 2D surfaces, the importance of 3D culture models cannot be overlooked. Here the methods to transition PS to specialized 3D culture surfaces are also reviewed. Specifically, casting, electrospinning, 3D printing, and microcarrier approaches to shift PS to a 3D culture surface are highlighted. The breadth of applications of the material makes it impossible to highlight every use, but the aim remains to demonstrate the versatility and potential as both a general and custom cell culture surface. The review concludes with emerging scaffolding approaches and, based on the findings, presents our insights on the future steps for PS as a tissue culture platform.

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

    Science.gov (United States)

    Benkocká, Monika; Kolářová, Kateřina; Matoušek, Jindřich; Semerádtová, Alena; Šícha, Václav; Kolská, Zdeňka

    2018-05-01

    The surface of polystyrene foil (PS) was chemically modified. Firstly, the surface was pre-treated with Piranha solution. The activated surface was grafted by selected amino-compounds (cysteamine, ethylenediamine or chitosan) and/or subsequently grafted with five members of inorganic metallaboranes. Selected surface properties were studied by using various methods in order to indicate significant changes before and after individual modification steps of polymer foil. Elemental composition of surface was conducted by using X-ray photoelectron spectroscopy, chemistry and polarity by infrared spectroscopy and by electrokinetic analysis, wettability by goniometry, surface morphology by atomic force microscopy. Antimicrobial tests were performed on individual samples in order to confirm antimicrobial impact. Our results show slight antibacterial activity of PS modified with SK5 for Escherichia coli in comparison with the rest of the tested borane. On the other hand molecules of all tested metallaboranes could easier pierce through bacterial cell of Staphylococcus epidermidis due to absence of outer membrane (phospholipid bilayer). Some borane grafted on PS surface embodies the strong activity for Staphylococcus epidermidis and also for Desmodesmus quadricauda growth inhibition.

  3. 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.

  4. Synthesis and characterization of polystyrene-starch polyblend

    International Nuclear Information System (INIS)

    Tetty Kemala; M Syaeful Fahmi; Suminar S Achmadi

    2010-01-01

    Polystyrene foam (PS) is a polymer that is widely used but not biodegradable. Therefore, PS-starch polyblend was developed. In this research the effect of glycerol as plasticizer was evaluated based on mechanical and thermal analyses. PS-starch polyblends were produced by mixing PS and starch solution with composition ratios of 60:40, 65:35, 70:30, 75:25, and 80:20 percent by weight. Polylactic acid (20 %) was added as compatibilizer. The polyblends were analyzed its tensile strength, thermal properties, and density. The PS-starch polyblends were white opaque in color and fragile. The properties of tensile strength and density of the polyblends were in the range of that of pure PS. The tensile strength and density increases as PS constituents increasing with the best composition ratio of 80 PS to 20 of starch. Peak of glass transition and melting point seen a single on composition ration 80 PS to 20 of starch. Additional amount of glycerol did not affect the thermal property, but has caused a slight decrease in tensile strength and density. (author)

  5. Host polymer influence on dilute polystyrene segmental dynamics

    Science.gov (United States)

    Lutz, T. R.

    2005-03-01

    We have utilized deuterium NMR to investigate the segmental dynamics of dilute (2%) d3-polystyrene (PS) chains in miscible polymer blends with polybutadiene, poly(vinyl ethylene), polyisoprene, poly(vinyl methylether) and poly(methyl methacrylate). In the dilute limit, we find qualitative differences depending upon whether the host polymer has dynamics that are faster or slower than that of pure PS. In blends where PS is the fast (low Tg) component, segmental dynamics are slowed upon blending and can be fit by the Lodge-McLeish model. When PS is the slow (high Tg) component, PS segmental dynamics speed up upon blending, but cannot be fit by the Lodge-McLeish model unless a temperature dependent self-concentration is employed. These results are qualitatively consistent with a recent suggestion by Kant, Kumar and Colby (Macromolecules, 2003, 10087), based upon data at higher concentrations. Furthermore, as the slow component, we find the segmental dynamics of PS has a temperature dependence similar to that of its host. This suggests viewing the high Tg component dynamics in a miscible blend as similar to a polymer in a low molecular weight solvent.

  6. Radioinduced grafting of acrylic acid on expanded polystyrene matrices

    International Nuclear Information System (INIS)

    Postolache, C.; Simion, Corina; Dragomir, A.; Ponta, C.; Chirvasoiu, G.; Postolache, Carmen

    1998-01-01

    The unfixed surface radioactive contamination for low energy β radionuclides ( 3 H and 14 C) is determined by wiping the checked surfaces with sponge of absorbent materials. The activity built up by this sponge is measured by a liquid scintillator spectrometer. In this work, a method of obtaining sponges of expanded polystyrene with hydrophobic surface by radioinduced grafting of the acrylic acid is presented. These sponges have diameters of 28 mm, thicknesses of 1.5 - 2 mm and density of 22 mg/cm 3 . The samples were immersed in a grafting solution with the following composition: acrylic acid 30%, Cu SO 4 1%; water 69% which were deeply impregnated in repeated operations under vacuum and pressure conditions, respectively. Finally, the samples were exposed to γ radiation emitted by a 60 Co source (IETI 10 000 - IFIN-HH). The dose rates were 0.3, 0.5 and 1 Mrad/h. The range of the absorbed doses was 1 - 25 Mrad. The yields of radiochemical grafting have been determined by gravimetric, spectrophotometric and radiometric methods. The grafting agent used was 3 H labelled acrylic acid. The solvation capacity and the quenching characteristics of the grafted sponges in liquid scintillators, as well as the sampling yields have been analyzed as function of irradiation procedure and the percentage of grafted acrylic fragments. The superficial grafting of the acrylic acid has been carried out by the mentioned technique, leading to the increase of the wiping efficiency of the unfixed surface contaminating activity, without changes of polymer solubility in liquid scintillators and without the perturbation of the radioactivity detection process. (authors)

  7. The entry of free radicals into polystyrene latex particles

    International Nuclear Information System (INIS)

    Adams, M.E.; Trau, M.; Gilbert, R.C.; Napper, D.R.

    1988-01-01

    Mechanistic understanding of the processes governing the kinetics of emulsion polymerization has both scientific and technical interest. One component of this process that is poorly understood at present is that of free radical entry into latex particles. Measurements were made of the entry rate coefficient as a function of temperature for free radicals entering polystyrene latex particles in seeded emulsion polymerizations initiated by γ-rays. The activation energy for entry was found to be less than 24 ± 3 kJ mol -1 , consistent with entry being controlled by a physical (e.g. diffusional) rather than a chemical process. Measurement of the entry rate coefficient as a function of the γ-ray dose rate suggested that the factors that determine the entry rate when the primary free radicals are uncharged are similar to those that determine the entry rate for charged free radicals derived from chemical initiation by peroxydisulfate. This result was consistent with measurements of the entry rate coefficient of charged free radicals derived from peroxydisulfate; these data were found to be virtually independent of both the extent of the latex surface coverage by the anionic surfactant sodium dodecyl sulfate and the ionic strength of the continuous phase. The data refute several proposals given in the literature for the rate-determining step for entry, being inconsistent with control by collision of free radicals with the latex particles, surfactant desorption, and an electrostatic barrier arising from the colloidal nature of the entering free radical. The origin of the activation energy for entry remains obscure

  8. 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

  9. 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.

  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 (pentacene thin film transistor (μ: ~2 cm(2)/(V s), on/off ratio, >1 × 10(4)) and complementary inverter (DC gains, ~20) could be fabricated.

  11. Effect of salivary secretory IgA on the adhesion of Candida albicans to polystyrene.

    Science.gov (United States)

    San Millán, R; Elguezabal, N; Regúlez, P; Moragues, M D; Quindós, G; Pontón, J

    2000-09-01

    Attachment of Candida albicans to plastic materials of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In an earlier study, it was shown that adhesion of C. albicans to polystyrene, a model system to study the adhesion of C. albicans to plastic materials, can be partially inhibited with an mAb directed against cell wall polysaccharides of C. albicans. In the present study, the role of whole saliva in the adhesion of C. albicans to polystyrene has been investigated, and three mAbs directed against epitopes of cell wall mannoproteins have been used to mimic the inhibitory effect observed with salivary secretory IgA (sIgA) on the adhesion of C. albicans to polystyrene. In the absence of whole saliva, adherence of C. albicans 3153 increased with germination. However, the presence of whole saliva enhanced the adhesion to polystyrene of C. albicans 3153 yeast cells but decreased the adhesion of germinated cells. The enhancement of adhesion of yeast cells to polystyrene mediated by saliva was confirmed with an agerminative mutant of C. albicans 3153. The inhibition of the adhesion of C. albicans 3153 germ tubes to polystyrene was due to the salivary sIgA since sIgA-depleted saliva enhanced the adhesion of C. albicans 3153 to polystyrene. The inhibitory effect mediated by sIgA was not related to the inhibition of germination but to the blockage of adhesins expressed on the cell wall surface of the germ tubes. The three mAbs studied reduced the adhesion of C. albicans 3153 to polystyrene at levels equivalent to those for purified sIgA. The highest reduction in the adhesion was obtained with the IgA mAb N3B. The best results were obtained when the three mAbs were combined. The results suggest that whole saliva plays a different role in the adhesion of C. albicans to polystyrene depending on the morphological phase of C. albicans. These results may give new insights into the

  12. Estimation of free volumes of polystyrene by positron annihilation life-time technique

    International Nuclear Information System (INIS)

    Li, Hong-Ling; Ujihira, Yusuke; Nanasawa, Atsushi.

    1996-01-01

    Differences of size, content, and size distribution of free volumes in linear and three-armed polystyrenes, synthesized by radical, and anionic processes, were observed by positron annihilation lifetime measurements. For the polystyrene samples of different architectures and molecular weight distributions, the temperature dependence of an average free volume radius was quite similar to each other. The radius increased with increasing temperature (T), from 0.27 nm (60 K) to 0.30 nm (glass transition temperature: T g = 363 K), then to 0.35 nm (423 K), showing αβ transition temperature about 300 K. With increasing T, the free volume content decreased from 35% (60 K) to 25% (260 K) for radically polymerized linear polystyrene and to 22% (320 K) for anionically polymerized three-armed polystyrene, and then turned to increase to 35% at 350 K and 400 K, respectively. In contrast, the content for anionically polymerized linear polystyrene decreased from 45% (60 K) to 33% (300 K) and turned to increase to 35% at 350-400 K. The free volume content decreased reciprocally with an increase in the molecular weight at 333 K, suggesting differences in molecular motion between the edge and middle portions of the chain molecule. (author)

  13. 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.

  14. 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.

  15. Impact of water chemistry on surface charge and aggregation of polystyrene microspheres suspensions.

    Science.gov (United States)

    Lu, Songhua; Zhu, Kairuo; Song, Wencheng; Song, Gang; Chen, Diyun; Hayat, Tasawar; Alharbi, Njud S; Chen, Changlun; Sun, Yubing

    2018-07-15

    The discharge of microplastics into aquatic environment poses the potential threat to the hydrocoles and human health. The fate and transport of microplastics in aqueous solutions are significantly influenced by water chemistry. In this study, the effect of water chemistry (i.e., pH, foreign salts and humic acid) on the surface charge and aggregation of polystyrene microsphere in aqueous solutions was conducted by batch, zeta potentials, hydrodynamic diameters, FT-IR and XPS analysis. Compared to Na + and K + , the lower negative zeta potentials and larger hydrodynamic diameters of polystyrene microspheres after introduction of Mg 2+ were observed within a wide range of pH (2.0-11.0) and ionic strength (IS, 0.01-500mmol/L). No effect of Cl - , HCO 3 - and SO 4 2- on the zeta potentials and hydrodynamic diameters of polystyrene microspheres was observed at low IS concentrations (10mmol/L). The zeta potentials of polystyrene microspheres after HA addition were decreased at pH2.0-11.0, whereas the lower hydrodynamic diameters were observed at pH<4.0. According to FT-IR and XPS analysis, the change in surface properties of polystyrene microspheres after addition of hydrated Mg 2+ and HA was attributed to surface electrostatic and/or steric repulsions. These investigations are crucial for understanding the effect of water chemistry on colloidal stability of microplastics in aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. 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

  17. Application of 60Co γ-ray irradiated polystyrene microplate for anti-HCV ELISA

    International Nuclear Information System (INIS)

    Feng Bo; Zeng Hongyan; Tang Yufang; Wang Lu

    2005-01-01

    In order to explore the effect of 60 Co γ-ray irradiation on minor polypeptides absorption of polystyrene microplate, an indirect ELISA detection of anti-HCV was established, 60 Co γ-ray irradiated polystyrene microplates and the controls (without irradiation or UV-irradiated) were applied to absorb recombinant HCV antigens respectively. Cooperated with Bovine antihuman IgG labelled HRP, their related indices of sensitivity, specificity, homogeneity and stability were determinate. The results indicated that, optimum dose of the γ-ray irradiation is 8 kGy, and compared with the controls, detection sensitivity and homogeneity of the polystyrene microplate irradiated to 8 kGy could be improved markedly. (authors)

  18. Synthesis of magnetic hollow silica using polystyrene bead as a template

    International Nuclear Information System (INIS)

    Wu, W.; Caruntu, D.; Martin, A.; Yu, M.H.; O'Connor, C.J.; Zhou, W.L.; Chen, J.-F.

    2007-01-01

    In this paper, we report a new route to synthesize novel magnetic hollow silica nanospheres (MHSNs) using polystyrene particles as sacrificial templates, and TEOS and Fe 3 O 4 as precursors. TEM, EDS, XRD, and SQUID were applied to characterize MHSNs. TEM and EDS results show that the MHSNs consist of about 200 nm of hollow cores and ∼35 nm shells with ∼10 nm of Fe 3 O 4 nanoparticles embedded. The polystyrene beads were successfully removed by immersing the as-prepared silica nanocomposite in a toluene solution. XRD results demonstrate that the Fe 3 O 4 magnetic nanoparticles still keep spinel structure even heated at low temperature. The surface status of the polystyrene beads and Fe 3 O 4 nanoparticles has an important effect on the formation of the MHSNs. The MHSNs present a superparamagnetism at room temperature by SQUID measurement. The MHSNs have potential applications in biosystem and nanomedicine

  19. Surface modification and particles size distribution control in nano-CdS/polystyrene composite film

    International Nuclear Information System (INIS)

    Min Zhirong; Ming Qiuzhang; Hai Chunliang; Han Minzeng

    2003-01-01

    Preparation of nano-CdS particles with surface thiol modification by microemulsion method and their influences on the particle size distribution in highly filled polystyrene-based composites were studied. The modified nano-CdS was characterized by X-ray photoelectron spectroscopy (XPS), light absorption and emission measurements to reveal the morphologies of the surface modifier, which are consistent with the surface molecules packing calculation. The morphologies of the surface modifier exerted a great influence not only on the optical performance of the particles themselves, but also on the size distribution of the particle in polystyrene matrix. A monolayer coverage with tightly packed thiol molecules was believed to be most effective in promoting a uniform particle size distribution and eliminating the surface defects that cause radiationless recombination. Control of the particles size distribution in polystyrene can be attained by adjusting surface coverage status of the thiol molecules based on the strong interaction between the surface modifier and the matrix

  20. 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.

  1. Radiosynthesis and in vitro evaluation of the polystyrene particles as a promising probe in biomedical sciences

    International Nuclear Information System (INIS)

    Chen Jianmin; Tan Mingguang; Wu Yuanfang; Zhang Guilin; Li Yan

    2005-01-01

    Polystyrene particles with precise monodisperse particle size distributions ranging from 20nm to 90μm is now commercially available and it has very useful and versatile applications in many life sciences research fields. A simple direct labeling method was used to synthesis the iodinated ultrafine polystyrene particles. The assay of X-ray photoelectron spectroscopy(XPS) as well as Fourier Transform Infrared Spectroscopy (FTIR) indicated the formation of stable covalent bond to aryl group of the polymer particles. The purified radiosynthesis product was incubated with serum of rat, and then evaluated by in vitro stability test. The result showed that radioiodinated ultrafine polystyrene particles were largely unmetablized at 2 hours post-exposure, indicating the potential useful application of this widely used polymer particles as a promising probe in biomedical and pharmaceutical sciences.

  2. Few-layer graphene growth from polystyrene as solid carbon source utilizing simple APCVD method

    Science.gov (United States)

    Ahmadi, Shahrokh; Afzalzadeh, Reza

    2016-07-01

    This research article presents development of an economical, simple, immune and environment friendly process to grow few-layer graphene by controlling evaporation rate of polystyrene on copper foil as catalyst and substrate utilizing atmospheric pressure chemical vapor deposition (APCVD) method. Evaporation rate of polystyrene depends on molecular structure, amount of used material and temperature. We have found controlling rate of evaporation of polystyrene by controlling the source temperature is easier than controlling the material weight. Atomic force microscopy (AFM) as well as Raman Spectroscopy has been used for characterization of the layers. The frequency of G‧ to G band ratio intensity in some samples varied between 0.8 and 1.6 corresponding to few-layer graphene. Topography characterization by atomic force microscopy confirmed Raman results.

  3. Site-specific fragmentation of polystyrene molecule using size-selected Ar gas cluster ion beam

    International Nuclear Information System (INIS)

    Moritani, Kousuke; Mukai, Gen; Hashinokuchi, Michihiro; Mochiji, Kozo

    2009-01-01

    The secondary ion mass spectrum (SIMS) of a polystyrene thin film was investigated using a size-selected Ar gas cluster ion beam (GCIB). The fragmentation in the SIM spectrum varied by kinetic energy per atom (E atom ); the E atom dependence of the secondary ion intensity of the fragment species of polystyrene can be essentially classified into three types based on the relationship between E atom and the dissociation energy of a specific bonding site in the molecule. These results indicate that adjusting E atom of size-selected GCIB may realize site-specific bond breaking within a molecule. (author)

  4. Synthesis and characterization of the polystyrene - asphaltene graft copolymer BY FT-IR spectroscopy

    International Nuclear Information System (INIS)

    Leo, Adan Yovani; Salazar Ramiro

    2008-01-01

    The creation of new polymer compounds to be added to asphalt has drawn considerable attention because these substances have succeeded in modifying the asphalt rheological characteristics and physical properties for the enhancement of its behavior during the time of use. This work explains the synthesis of a new graft copolymer based on an asphalt fraction called asphaltene, modified with maleic anhydride. Polystyrene functionalization is conducted in a parallel fashion in order to obtain polybenzylamine resin with an amine - NH2 free group that reacts with the anhydride graft groups in the asphaltene, thus obtaining the new Polystyrene/Asphaltene graft copolymer

  5. Altered behavior, physiology, and metabolism in fish exposed to polystyrene nanoparticles

    DEFF Research Database (Denmark)

    Mattsson, Karin; Ekvall, Mikael T; Hansson, Lars-Anders

    2015-01-01

    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...

  6. Measuring thermal conductivity of polystyrene nanowires using the dual-cantilever technique.

    Science.gov (United States)

    Canetta, Carlo; Guo, Samuel; Narayanaswamy, Arvind

    2014-10-01

    Thermal conductance measurements are performed on individual polystyrene nanowires using a novel measurement technique in which the wires are suspended between two bi-material microcantilever sensors. The nanowires are fabricated via electrospinning process. Thermal conductivity of the nanowire samples is found to be between 6.6 and 14.4 W m(-1) K(-1) depending on sample, a significant increase above typical bulk conductivity values for polystyrene. The high strain rates characteristic of electrospinning are believed to lead to alignment of molecular polymer chains, and hence the increase in thermal conductivity, along the axis of the nanowire.

  7. POTENTIAL USE OF GRAFT COPOLYMERS OF MERCERIZED FLAX AS FILLER IN POLYSTYRENE COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    Susheel Kalia

    2008-11-01

    Full Text Available Graft copolymerization of binary vinyl monomers onto mercerized flax fiber was carried out for the enhancement of mechanical properties of polystyrene composites. Binary vinyl monomer mixture of AA+AN has been found to show maximum grafting (33.55% onto mercerized flax. Graft copolymers thus synthesized were characterized with FT-IR spectroscopy, SEM, and TGA techniques. Mercerized flax (MF showed maximum thermal stability in comparison to graft copolymers. It has been found that polystyrene composites reinforced with graft copolymers showed improvement in mechanical properties such as wear resistance, compressive strength, and tensile strength.

  8. Thermo-mechanical characterization of a monochlorophenyl, hepta isobutyl polyhedral oligomeric silsesquioxane/polystyrene composite

    International Nuclear Information System (INIS)

    Blanco, Ignazio; Bottino, Francesco A.; Cicala, Gianluca; Cozzo, Giulia; Latteri, Alberta; Recca, Antonino

    2014-01-01

    The thermal and mechanical properties of a monochlorophenyl, hepta isobutyl Polyhedral Oligomeric Silsesquioxane/Polystyrene (ph,hib-POSS/PS) composite were studied and compared with those of pristine polymer. ph,hib-POSS/PS system was prepared by solubilization and precipitation of Polystyrene (PS) in the presence of POSS. Scanning Electron Microscopy (SEM) was performed to check the distribution of the filler in the polymer matrix. Dynamic Mechanical Analysis (DMA) was carried out to measure viscoelastic properties of solid samples. Degradations were carried out into a thermobalance and the obtained thermogravimetric (TG) and differential thermogravimetric (DTG) curves were discussed and interpreted

  9. Synchrotron X-ray scattering characterization of the molecular structures of star polystyrenes with varying numbers of arms.

    Science.gov (United States)

    Jin, Sangwoo; Higashihara, Tomoya; Jin, Kyeong Sik; Yoon, Jinhwan; Rho, Yecheol; Ahn, Byungcheol; Kim, Jehan; Hirao, Akira; Ree, Moonhor

    2010-05-20

    We have synthesized well-defined multiarmed star polystyrenes, with 6, 9, 17, 33, and 57 arms, and studied their molecular shapes and structural characteristics in a good solvent (tetrahydrofuran at 25 degrees C) and in a theta (Theta) solvent (cyclohexane at 35 degrees C) by small-angle X-ray scattering (SAXS) using a synchrotron radiation source. Analysis of the SAXS data provided a detailed characterization of the molecular shapes, including the contributions of the blob morphology of the arms, the radius of gyration, the paired distance distribution, the radial electron density distribution, and the Zimm-Stockmayer and Roovers g-factor, for the multiarmed star polystyrenes. In particular, the molecular shapes of the star polystyrenes were found to change from a fuzzy ellipsoid, for the 6-armed polystyrene, to a fuzzy sphere, for the 57-armed polystyrene, with an increasing number of arms. The ellipsoidal character of the star polystyrenes with fewer arms may originate from the extended anisotropically branched architecture at the center of the molecule. The arms of the star polystyrenes were found to be more extended than those of the linear polystyrenes. Furthermore, the degree of chain extension in the arms increased with the number of arms.

  10. A study of the effect of polystyrene sulfonation on the performance of terephthaloyl chloride-dihydroxydiphenyl sulfone copolymer/polystyrene system

    Science.gov (United States)

    Kahraman, R.; Kahn, K. A.; Ali, S. A.; Hamid, S. H.; Sahin, A. Z.

    1998-12-01

    Thermal, morphological, and mechanical properties of composites of a liquid crystalline copolymer (LCP) poly(terephthaloyl chloride)-co-(p,p’-dihydroxydiphenyl sulfone) with polystyrene (PS) and sulfonated polystyrene (SPS) are presented and discussed. Sulfonation of polystyrene was expected to improve the interfacial adhesion by introducing hydrogen bonding in the LCP/PS system. The degree of sulfonation was 11 %. The incompatibility (lack of proper interfacial adhesion) of the LCP/PS system resulted in sharp decrease in the composite tensile strength with LCP addition. The performance of the system did not change when processed at a higher temperature (270 °C instead of 225 °C). While a composite plate of 25% LCP/PS could not be fabricated, it was possible for LCP/SPS (processed at 215 °C), indicating some improvement in interfacial bonding by sulfonation. Sulfonation of PS resulted in fracture with some degree of plastic deformation for pure SPS matrix and also the LCP/SPS system with the lowest LCP content (1 wt%), whereas plastic deformation was not observed for PS used as received. The strength of the LCP/SPS system also decreased with increase in LCP content, indicating that 11% sulfonation is not sufficient to introduce significant compatibility, but it was not as dramatic as that for LCP/PS. The performance of the LCP/SPS system was not affected significantly by heat treatment at the process temperature.

  11. Determination of several trace metals in biological materials by PIXE analysis after solvent extraction and polystyrene-film collection

    International Nuclear Information System (INIS)

    Iwata, Yoshihiro; Korenaga, Tatsumi; Suzuki, Nobuo

    1991-01-01

    Traces of vanadium, manganese, iron, cobalt, nickel, copper, and zinc were quantitatively extracted with diethyldithiocarbamate (DDTC) in benzene from a digested solution of biological materials and the metal-DDTC complexes were collected into a small amount of polystyrene foam produced by lyophilization of the benzene extract after addition of polystyrene. The polystyrene foam was dissolved in benzene and spread on Mylar film. After drying, a polystyrene film containing metal-DDTC complexes was produced on Mylar film, and then the polystyrene film was peeled from the Mylar film. This film was subjected to PIXE analysis. This method was applied to NBS SRM 1572 citrus leaves and a marine macroalgal sample, and 6 trace metals were simultaneously and accurately determined. (author)

  12. Tuning the wettability of calcite cubes by varying the sizes of the polystyrene nanoparticles attached to their surfaces

    International Nuclear Information System (INIS)

    He Yongjun; Li Tanliang; Yu Xiangyang; Zhao Shiyong; Lu Jianhua; He Jia

    2007-01-01

    The wettability of calcite cubes was tuned by varying the sizes of the polystyrene nanoparticles attached to their surfaces via a dispersion polymerization. The products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersion spectrum (EDS) and Fourier transformation infrared spectrum (FTIR). The results showed that the hydrophobicity of the calcite cubes was enhanced with the increase of the size of the polystyrene nanoparticles attached. Using polystyrene nanoparticle-attached calcite cubes (PNACC) as emulsifiers, stable water-in-tricaprylin Pickering emulsions were produced. By gelling the water droplets of the Pickering emulsions, the hierarchical structures of polystyrene nanoparticle-attached calcite cube-armored microspheres were obtained. The polystyrene nanoparticle-attached calcite cubes were expected to have novel surface properties similar neither to traditional Pickering particles, nor to macroscopically asymmetrical Janus particles

  13. Small angle X-ray scattering study on the conformation of polystyrene in the anti-solvent process of supercritical fluids

    International Nuclear Information System (INIS)

    Liu Yi; Wang Hongli; Zhao Xin; Chen Na; Li Dan; Liu Zhimin; Han Buxing; Rong Lixia; Zhao Hui; Wang Jun; Dong Baozhong

    2003-01-01

    The conformation of polystyrene in the anti-solvent process of supercritical fluids (compressed CO 2 + polystyrene + tetrahydrofuran) is studied by synchrotron radiation X-ray small angle scattering (SAXS). Coil-to-globule transform of polystyrene chain is observed with increasing the concentration of CO 2 . It is found that polystyrene coils at the pressure lower than cloud point pressure (p c ) and changes into globule with uniform density at the pressure higher than p c

  14. Direct observation of interfacial C60 cluster formation in polystyrene-C60 nanocomposite films

    International Nuclear Information System (INIS)

    Han, Joong Tark; Lee, Geon-Woong; Kim, Sangcheol; Lee, Hae-Jeong; Douglas, Jack F; Karim, Alamgir

    2009-01-01

    Large interfacial C 60 clusters were directly imaged at the supporting film-substrate interface in physically detached polystyrene-C 60 nanocomposite films by atomic force microscopy, confirming the stabilizing mechanism previously hypothesized for thin polymer films. Additionally, we found that the C 60 additive influences basic thermodynamic film properties such as the interfacial energy and the film thermal expansion coefficient.

  15. Chain conformation change upon heating for Pauci-chain polystyrene microsphere made by microemulsion polymerization

    NARCIS (Netherlands)

    Ming, W.; Zhao, Y.Q.; Zhao, Jun; Fu, Shoukuan; Jones, F.N.

    2000-01-01

    The conformation change of pauci-chain polystyrene microsphere (micro-PS) upon heating was investigated by in-situ FTIR. For the peaks at 1492 and 1452 cm-1 due to phenyl ring semicircle stretch, there are two discontinuities in the plots of peak height versus temperature. The first discontinuity at

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

    KAUST Repository

    Peinemann, Klaus-Viktor; Karunakaran, Madhavan

    2015-01-01

    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.

  17. Improved functional immobilization of llama single-domain antibody fragments to polystyrene surfaces using small peptides

    NARCIS (Netherlands)

    Harmsen, M.M.; Fijten, H.P.D.

    2012-01-01

    We studied the effect of different fusion domains on the functional immobilization of three llama single-domain antibody fragments (VHHs) after passive adsorption to polystyrene in enzyme-linked immunosorbent assays (ELISA). Three VHHs produced without any fusion domain were efficiently adsorbed to

  18. 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,

  19. Water contentwater of determination of cationic polystyrene sulfonate resins by infrared spectrophotometry

    International Nuclear Information System (INIS)

    Noki, V.

    1987-01-01

    A method of the determination of water content in polystyrene sulfonate ion-exchange resins in the presence of alkaline earth counter-ions by I.R. spectrophotometry is proposed. This method does not hold in the case of transition metal due to the formation of coordinated complexes with water molecules.

  20. 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

  1. 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...

  2. Novel one-step route for synthesizing CdS/polystyrene nanocomposite hollow spheres.

    Science.gov (United States)

    Wu, Dazhen; Ge, Xuewu; Zhang, Zhicheng; Wang, Mozhen; Zhang, Songlin

    2004-06-22

    CdS/polystyrene nanocomposite hollow spheres with diameters between 240 and 500 nm were synthesized under ambient conditions by a novel microemulsion method in which the polymerization of styrene and the formation of CdS nanoparticles were initiated by gamma-irradiation. The product was characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA), which show the walls of the hollow spheres are porous and composed of polystyrene containing homogeneously dispersed CdS nanoparticles. The quantum-confined effect of the CdS/polystyrene nanocomposite hollow spheres is confirmed by the ultraviolet-visible (UV-vis) and photoluminescent (PL) spectra. We propose that the walls of these nanocomposite hollow spheres originate from the simultaneous synthesis of polystyrene and CdS nanoparticles at the interface of microemulsion droplets. This novel method is expected to produce various inorganic/polymer nanocomposite hollow spheres with potential applications in the fields of materials science and biotechnology.

  3. Preparation of polystyrene brush film by radical chain-transfer polymerization and micromechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Jing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Chen Miao [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: miaochen99@yahoo.com; An Yanqing [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Liu Jianxi [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yan Fengyuan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: fyyan@lzb.ac.cn

    2008-12-30

    A radical chain-transfer polymerization technique has been applied to graft-polymerize brushes of polystyrene (PSt) on single-crystal silicon substrates. 3-Mercapto-propyltrimethoxysilane (MPTMS), as a chain-transfer agent for grafting, was immobilized on the silicon surface by a self-assembling process. The structure and morphology of the graft-functionalized silicon surfaces were characterized by the means of contact-angle measurement, ellipsometric thickness measurement, Fourier transformation infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The nanotribological and micromechanical properties of the as-prepared polymer brush films were investigated by frictional force microscopy (FFM), force-volume analysis and scratch test. The results indicate that the friction properties of the grafted polymer films can be improved significantly by the treatment of toluene, and the chemically bonded polystyrene film exhibits superior scratch resistance behavior compared with the spin-coated polystyrene film. The resultant polystyrene brush film is expected to develop as a potential lubrication coating for microelectromechanical systems (MEMS)

  4. Cathodic electrogenerated chemiluminescence of aromatic Tb(III) chelates at polystyrene-graphite composite electrodes

    International Nuclear Information System (INIS)

    Salminen, Kalle; Grönroos, Päivi; Tuomi, Sami; Kulmala, Sakari

    2017-01-01

    Tb(III) chelates exhibit intense hot electron-induced electrogenerated chemiluminescence during cathodic polarization of metal/polystyrene-graphite (M/PG) electrodes in fully aqueous solutions. The M/PG working electrode provides a sensitive means for the determination of aromatic Tb(III) chelates at nanomolar concentration levels with a linear log-log calibration curve spanning more than five orders of magnitude. The charge transport and other properties of these novel electrodes were studied by electrochemiluminescence measurements and cyclic voltammetry. The present composite electrodes can by utilized both under pulse polarization and DC polarization unlike oxide-coated metal electrodes which do not tolerate cathodic DC polarization. The present cost-effective electrodes could be utilized e.g. in immunoassays where polystyrene is extensively used as a solid phase for various bioaffinity assays by using electrochemiluminescent Tb(III) chelates or e.g. Ru(bpy) 3 2+ as labels. - Highlights: • Generation of hydrated electrons at Polystyrene-graphite electrodes. • The insulating polystyrene layer on the outer electrode surface seems necessary. • Hydrated electrons are able to produce chemiluminescence. • Strongest signal and lowest std. dev. achieved at same graphite weight fraction.

  5. Synthesis and Linear Viscoelasticity of Polystyrene Stars with a Polyketone Core

    NARCIS (Netherlands)

    Polgar, L. M.; Lentzakis, H.; Collias, D.; Snijkers, F.; Lee, S.; Chang, T.; Sakellariou, G.; Wever, D. A. Z.; Toncelli, C.; Broekhuis, A. A.; Picchioni, F.; Gotsis, A. D.; Vlassopoulos, D.

    2015-01-01

    We report on a novel synthetic route to synthesize relatively large quantities of polystyrene (PS) star polymers with targeted arm functionality and molar mass and their theological properties in the molten state. The synthetic route involves grafting styrene monomers onto a modified (aliphatic,

  6. 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...

  7. PARTICLEBOARDS PRODUCED WITH Eucalyptus grandis W. Hill ex Maiden POLYSTYRENE AND POLYETHYLENE THEREPHTHALATE PARTICLES

    Directory of Open Access Journals (Sweden)

    Antônio da Silva Maciel

    2004-06-01

    Full Text Available This research investigated the properties of wood particleboards, containing particles of polystyrene (PS and polyethylene therephthalate (PET. Particleboards were produced with 0%, 25% or 50% of polystyrene and 100%, 75% or 50% of Eucalyptus grandis particles. Additional boards were produced with two amounts of PET/PS (5/20% or 10/40% and 75% or 50% wood particles. As binding agents three amounts (0%, 4% or 6% of urea-formaldehyde or phenol-formaldehyde adhesive and three amounts of polystyrene in toluene solution (0%, 4% or 6% were used. One-layer boards, measuring approximately 400,0 x 400,0 x 10,0 mm with density approximately equal to 0,60 g/cm3, were produced. Internal bond, modulus of rupture and elasticity, screw withdrawal, as well water absorption and thickness swelling, after 24 hours of immersion were determined. All mechanical boards’ properties were superior to the established by ANSI/A 208.1-1993 standards. All wood/plastic particleboards absorbed more water then those observed in commercial boards. However the observed thickness swelling was quite similar to the values of commercial wood particleboards. Boards in which the solution of polystyrene was applied were, in general, presented the best values for all properties.

  8. 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...

  9. (Quasi-) 2D Aggregation of Polystyrene-b-Dextran at the Air-Water Interface

    NARCIS (Netherlands)

    Bosker, Wouter T. E.; Stuart, Martien A. Cohen; Norde, Willem

    2013-01-01

    Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and

  10. Surface-enhanced Raman spectroscopy substrate based on Ag-coated self-assembled polystyrene spheres

    Science.gov (United States)

    Mikac, Lara; Ivanda, Mile; Gotić, Marijan; Janicki, Vesna; Zorc, Hrvoje; Janči, Tibor; Vidaček, Sanja

    2017-10-01

    The silver (Ag) films were deposited on the monodispersed polystyrene spheres that were drop-coated on hydrophilic glass substrates in order to form a self-assembled 2D monolayer. Thus prepared Ag films over polystyrene nanospheres (AgFONs) were used to record the surface-enhanced Raman scattering (SERS) spectra of rhodamine 6G (R6G) and pyridine (λex = 514.5 nm). AgFONs were prepared by depositing 120, 180 and 240 nm thick Ag layer on the 1000 nm polystyrene spheres and 80, 120, 160 and 200 nm thick Ag layer on the 350 nm spheres as well as on their mixture (350 + 1000 nm). The silver was deposited by electron beam evaporation technique. The best enhancement of the Raman signal for both test molecules was obtained using 180 nm Ag film deposited on the 1000 nm spheres and using 80 nm Ag film deposited on the 350 nm polystyrene spheres. The lowest detectable concentrations of R6G and pyridine were 10-9 mol L-1 and 1.2 × 10-3 mol L-1, respectively. This study has shown that AgFONs could be regarded as good and reproducible SERS substrate for analytical detection of various organic molecules.

  11. 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-...

  12. 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...

  13. Influence of electron beam irradiation on the impact properties of polystyrene/EPDM rubber blends

    NARCIS (Netherlands)

    Gisbergen, van J.G.M.; Sanden, van der M.C.M.; Haan, de J.W.; Ven, van de L.J.M.; Lemstra, P.J.

    1991-01-01

    The influence of electron beam (EB) irradiation on the impact properties of compatibilized polystyrene/ethylene-propylene-diene-monomer (PSIEPDM) blends was studied. The change in impact value upon irradiation proved to be strongly dependent on the type of compatibilizer used. Using a

  14. 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

  15. Mechanical properties and local mobility of atactic-polystyrene films under constant-shear deformation

    NARCIS (Netherlands)

    Hudzinskyy, D.; Michels, M.A.J.; Lyulin, A.V.

    2012-01-01

    We have performed molecular-dynamics simulations of atactic polystyrene thin films to study the effect of shear rate, pressure, and temperature on the stress-strain behaviour, the relevant energetic contributions and non-affine displacements of polymer chains during constant-shear deformation. Under

  16. Single-Step Nanoporation of Water-Immersed Polystyrene Film by Gaseous Nanobubbles

    Czech Academy of Sciences Publication Activity Database

    Tarábková, Hana; Janda, Pavel

    2016-01-01

    Roč. 32, č. 43 (2016), s. 11221-11229 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GAP208/12/2429 Institutional support: RVO:61388955 Keywords : Atomic force microscopy * Biocompatibility * Polystyrenes Subject RIV: CG - Electrochemistry Impact factor: 3.833, year: 2016

  17. Synthesis and characterization of an additive type super plasticizers obtained from plastics cups of polystyrene

    International Nuclear Information System (INIS)

    Araujo, Carolina G.L.; Freire, Carolina B.; Tello, Cledola C. de O.

    2013-01-01

    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

  18. Preparative-scale separation of C60 and C70 on polystyrene gel

    International Nuclear Information System (INIS)

    Guegel, A.; Becker, M.; Hammel, D.; Mindach, L.; Raeder, J.; Simon, T.; Wagner, M.; Muellen, K.

    1992-01-01

    Five grams of a mixture of C 60 /C 70 can be separated in 24 hours by gel permeation chromatography on polystyrene gel. The mobile phase can be completely recovered, and the method can be scaled up by a simple increase in the inner diameter of the column. (orig.) [de

  19. 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

  20. Functionalized polystyrene nanoparticles as a platform for studying bio–nano interactions

    Directory of Open Access Journals (Sweden)

    Cornelia Loos

    2014-12-01

    Full Text Available Nanoparticles of various shapes, sizes, and materials carrying different surface modifications have numerous technological and biomedical applications. Yet, the mechanisms by which nanoparticles interact with biological structures as well as their biological impact and hazards remain poorly investigated. Due to their large surface to volume ratio, nanoparticles usually exhibit properties that differ from those of bulk materials. Particularly, the surface chemistry of the nanoparticles is crucial for their durability and solubility in biological media as well as for their biocompatibility and biodistribution. Polystyrene does not degrade in the cellular environment and exhibits no short-term cytotoxicity. Because polystyrene nanoparticles can be easily synthesized in a wide range of sizes with distinct surface functionalizations, they are perfectly suited as model particles to study the effects of the particle surface characteristics on various biological parameters. Therefore, we have exploited polystyrene nanoparticles as a convenient platform to study bio–nano interactions. This review summarizes studies on positively and negatively charged polystyrene nanoparticles and compares them with clinically used superparamagnetic iron oxide nanoparticles.

  1. Worst case prediction of additives migration from polystyrene for food safety purposes: a model update

    DEFF Research Database (Denmark)

    Martinez Lopez, Brais; Gontard, Nathalie; Peyron, Stephane

    2018-01-01

    . These parameters were determined for the polymers most used by packaging industry (LLDPE, HDPE, PP, PET, PS, HIPS) from the diffusivity data available at that time. In the specific case of general purpose polystyrene, the diffusivity data published since then shows that the use of the equation with the original...

  2. (Quasi-) 2D aggregation of polystyrene-b-dextran at the air-water interface

    NARCIS (Netherlands)

    Bosker, W.T.E.; Cohen Stuart, M.A.; Norde, W.

    2013-01-01

    Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir–Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and

  3. 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 m...

  4. 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.

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

    NARCIS (Netherlands)

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

    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

  6. A model for the stress-strain behavior of toughened polystyrene. Part 2

    NARCIS (Netherlands)

    Sjoerdsma, S.D.; Heikens, D.

    1982-01-01

    The general stress-strain relationship derived in an earlier paper is applied to analyse experimental stress-strain curves of polystyrene-polyethylene blends. It is concluded from the stress and temperature dependence of the rates of craze initiation and craze growth that these rates can be

  7. The relationship between cellular adhesion and surface roughness in polystyrene modified by microwave plasma radiation

    Directory of Open Access Journals (Sweden)

    Biazar E

    2011-03-01

    Full Text Available Esmaeil Biazar1, Majid Heidari2, Azadeh Asefnezhad2, Naser Montazeri11Department of Chemistry, Islamic Azad University, Tonekabon Branch, Mazandaran; 2Department of Biomaterial Engineering, Faculty of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, IranBackground: Surface modification of medical polymers can improve biocompatibility. Pure polystyrene is hydrophobic and cannot provide a suitable environment for cell cultures. The conventional method for surface modification of polystyrene is treatment with plasma. In this study, conventional polystyrene was exposed to microwave plasma treatment with oxygen and argon gases for 30, 60, and 180 seconds.Methods and results: Attenuated total reflection Fourier transform infrared spectra investigations of irradiated samples indicated clearly the presence of functional groups. Atomic force microscopic images of samples irradiated with inert and active gases indicated nanometric surface topography. Samples irradiated with oxygen plasma showed more roughness (31 nm compared with those irradiated with inert plasma (16 nm at 180 seconds. Surface roughness increased with increasing duration of exposure, which could be due to reduction of the contact angle of samples irradiated with oxygen plasma. Contact angle analysis showed reduction in samples irradiated with inert plasma. Samples irradiated with oxygen plasma showed a lower contact angle compared with those irradiated by argon plasma.Conclusion: Cellular investigations with unrestricted somatic stem cells showed better adhesion, cell growth, and proliferation for samples radiated by oxygen plasma with increasing duration of exposure than those of normal samples.Keywords: surface topography, polystyrene, plasma treatment, argon, oxygen

  8. Synthesis of amylose-block-polystyrene rod-coil block copolymers

    NARCIS (Netherlands)

    Loos, Katja; Stadler, Reimund

    1997-01-01

    In the present communication we demonstrate the synthesis of a hybrid block copolymer based on the combination of a biopolymer (amylose) with a synthetic block (polystyrene). To obtain such materials, amino-functionalized polymers were modified with maltoheptaose moieties that serve as initiators

  9. Hydrophobic Polystyrene Passivation Layer for Simultaneously Improved Efficiency and Stability in Perovskite Solar Cells.

    Science.gov (United States)

    Li, Minghua; Yan, Xiaoqin; Kang, Zhuo; Huan, Yahuan; Li, Yong; Zhang, Ruxiao; Zhang, Yue

    2018-06-06

    The major restraint for the commercialization of the high-performance hybrid metal halide perovskite solar cells is the long-term stability, especially at the infirm interface between the perovskite film and organic charge-transfer layer. Recently, engineering the interface between the perovskite and spiro-OMeTAD becomes an effective strategy to simultaneously improve the efficiency and stability in the perovskite solar cells. In this work, we demonstrated that introducing an interfacial polystyrene layer between the perovskite film and spiro-OMeTAD layer can effectively improve the perovskite solar cells photovoltaic performance. The inserted polystyrene layer can passivate the interface traps and defects effectively and decrease the nonradiative recombination, leading to enhanced photoluminescence intensity and carrier lifetime, without compromising the carrier extraction and transfer. Under the optimized condition, the perovskite solar cells with the polystyrene layer achieve an enhanced average power efficiency of about 19.61% (20.46% of the best efficiency) from about 17.63% with negligible current density-voltage hysteresis. Moreover, the optimized perovskite solar cells with the hydrophobic polystyrene layer can maintain about 85% initial efficiency after 2 months storage in open air conditions without encapsulation.

  10. 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

  11. 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...

  12. Magnetization of large polystyrene peptide beads for capturing and expanding cancer cells

    International Nuclear Information System (INIS)

    Marik, Jan; Lau, D.H.; Song Aimin; Wang Xiaobing; Liu Ruiwu; Lam, K.S.

    2003-01-01

    A method is described for preparation of large magnetic polystyrene beads coupled with peptide ligands for surface receptors of lung cancer cells. We have demonstrated the feasibility of using these magnetic peptide beads for capturing and enriching lung cancer cells spiked into blood. These magnetic peptide beads potentially can be used to efficiently isolate cancer cells from body fluids

  13. 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

  14. One-step routes from di- and triblock copolymer precursors to hydrophilic nanoporous poly(acrylic acid)-b-polystyrene

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Jankova Atanasova, Katja; Schulte, Lars

    2008-01-01

    Nanoporous polystyrene with hydrophilic pores was prepared from di- and triblock copolymer precursors. The precursor material was either a poly(tert-butyl acryl ate)-b-polystyrene (PtBA-b-PS) diblock copolymer synthesized by atom transfer radical polymerization (ATRP) or a polydimethylsiloxane......-b-poly(tertbutyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer synthesized by a combination of living anionic polymerization and ATRP. In the latter copolymer, PS was the matrix and mechanically stable component, PtBA was converted by acidic deprotection to hydrophilic poly(acrylic acid) (PAA) providing...

  15. The influence of organo-bentonite clay on the processing and mechanical properties of nylon 6 and polystyrene composites

    International Nuclear Information System (INIS)

    Araujo, E.M.; Melo, T.J.A.; Santana, L.N.L.; Neves, G.A.; Ferreira, H.C.; Lira, H.L.; Carvalho, L.H.; A'vila, M.M.; Pontes, M.K.G.; Araujo, I.S.

    2004-01-01

    The influence of organoclay on the processing and mechanical properties of nylon 6 and polystyrene was investigated. A bentonite sample from Boa Vista/PB, Northeast of Brazil, was treated with alkyldimethylbenzylammonium chloride. After the treatment, the powder was characterized by thermal analysis and infrared spectroscopy. Composites were prepared by using a Torque rheometer. The results show the intercalation of quaternary ammonium salt in the structure of bentonite and organo-bentonite produced significant changes on the processing of the nylon 6 and polystyrene with increase in the viscosity and rigidity. However, the mechanical properties of polystyrene/organoclay system did not show significant changes

  16. 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

  17. 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.

  18. Extended x-ray absorption fine structure: Studies of zinc-neutralized sulfonated polystyrene ionomers

    International Nuclear Information System (INIS)

    Ding, Y.S.; Yarusso, D.J.; Pan, H.K.D.; Cooper, S.L.

    1984-01-01

    Extended x-ray absorption fine structure (EXAFS) measurements were performed on a series of zinc-neutralized sulfonated polystyrene ionomers and the local structure around the zinc atom was determined. An interference effect in the EXAFS signal between sulfur and oxygen atoms was found to be significant in these materials. A model for the local structure in the zinc-neutralized sulfonated polystyrene ionomers is proposed which suggests a highly ordered tetrahedral coordination of oxygen around the zinc atoms at a distance of 1.97 +- 0.02 A. In addition there are four sulfur atoms and four oxygen atoms at a distance of 3.15 +- 0.05 A. No zinc-zinc coordination within 5 A was detected in this study

  19. Molecular modeling and simulation of atactic polystyrene/amorphous silica nanocomposites

    International Nuclear Information System (INIS)

    Mathioudakis, I; Vogiatzis, G G; Tzoumanekas, C; Theodorou, D N

    2016-01-01

    The local structure, segmental dynamics, topological analysis of entanglement networks and mechanical properties of atactic polystyrene - amorphous silica nanocomposites are studied via molecular simulations using two interconnected levels of representation: (a) A coarse - grained level. Equilibration at all length scales at this level is achieved via connectivity - altering Monte Carlo simulations. (b) An atomistic level. Initial configurations for atomistic Molecular Dynamics (MD) simulations are obtained by reverse mapping well- equilibrated coarse-grained configurations. By analyzing atomistic MD trajectories, the polymer density profile is found to exhibit layering in the vicinity of the nanoparticle surface. The dynamics of polystyrene (in neat and filled melt systems) is characterized in terms of bond orientation. Well-equilibrated coarse-grained long-chain configurations are reduced to entanglement networks via topological analysis with the CReTA algorithm. Atomistic simulation results for the mechanical properties are compared to the experimental measurements and other computational works. (paper)

  20. Interfacial Effects on the Spherulitic Morphology of Isotactic Polystyrene Thin Films on Liquid Substrates

    Directory of Open Access Journals (Sweden)

    Takashi Sasaki

    2016-01-01

    Full Text Available The influence of interfaces on the morphology of flat spherulites of isotactic polystyrene (iPS grown in thin films on liquid substrates was investigated. Amorphous iPS thin films spin-cast from a solution were annealed for cold crystallization on glycerol and silicone oil (nonsolvents for iPS. The number density of grown spherulites was revealed to be higher on the glycerol substrate than on the silicone oil substrate. This implies that the primary nucleation rate of crystallization is greater at the iPS/glycerol interface than at the iPS/silicone oil interface. The results may be consistent with the previous findings that concern the molecular interaction between atactic polystyrene and nonsolvents at the interface. In some cases, holes were formed in the thin films during the cold crystallization due to dewetting, which also significantly affect the spherulite morphology via, for example, transcrystallization.

  1. 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.

  2. Enhancement of water retention by cross-linked carboxymethylcellulose through polystyrene grafting or γ irradiation

    International Nuclear Information System (INIS)

    Bhattacharjee, S.S.; Perlin, A.S.

    1975-01-01

    The absorbency and retention characteristics of crosslinked carboxymethylcellulose (CLCMC) with respect to water and saline can be substantially improved by two different treatments. One treatment involves γ-radioinduced grafting of polystyrene onto fibers of CLCMC. At a critical level of grafting (approximately 25 percent) the retentive capacity of the fibers is almost doubled. Particularly noteworthy is the sharp increase that follows an initial drop in retentivity. It is concluded the polystyrene becomes associated preferentially with residual ordered regions of the CLCMC macromolecule, through the localization of free radicals in these regions. A second means for enhancing the water and saline retention value of CLCMC, consists of subjecting the material to gamma irradiation from a 60 Co source. Dosages used have ranged from 1.0 to 4.8 megarads (MR), depending on the degree of substitution of the initial carboxymethylcellulose. (JGB)

  3. 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.

  4. 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.

  5. The impact of fluorescent dyes on the performances of polystyrene-based plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jun [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Deng, Cheng; Jiang, Huimin [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); Zheng, Zhanlong; Gong, Rui [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Bi, Yutie [Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology and Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621010 (China); Zhang, Lin, E-mail: zhlmy@sina.com [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Lin, Runxiong, E-mail: qdlrx@qust.edu.cn [Engineering Research Center of High Performance Polymer and Molding Technology, Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2016-11-01

    To investigate the influence of both the first luminescent additive and the wavelength-shifter on the performance of plastic scintillator, a series of polystyrene-based scintillator had been prepared by thermal polymerization. Three first luminescent additives (PPO, p-TP and b-PBD) and four wavelength-shifters (POPOP, Bis-MSB, Me-MSB and DPA) were added to the scintillators respectively. The comparison results showed that PPO and POPOP were the most adequate fluorescent dyes for the polystyrene-based plastic scintillator. Moreover, with the increase of the concentration of PPO and POPOP, the fluorescence intensity and light yield were increased firstly and then decreased. The plastic scintillator containing 2% PPO and 0.02% POPOP had the highest fluorescence intensity and light yield.

  6. Uniform formation of Au coated polystyrene core-shell structure using metallization process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoungseob; Koo, Jonghyun; Roh, Yonghan, E-mail: yhroh@skku.edu

    2011-08-01

    There are several methods for the fabrication of core-shell particles, including chemical reduction and self-assembly. In this study, the chemical reduction method was used to fabricate 100 nm, Au-coated polystyrene nanoparticles. The formation of the gold layer was based on the increase of gold coverage by the reaction with aniline and HAuCl{sub 4}. This method allowed for efficient control of the gold coverage and led to relatively stable products. The formation of Au clusters on the surface of the 100 nm polystyrene beads was characterized by scanning electron microscope and high resolution tunneling electron microscope. As a result, the Au-coated nanoparticles can be used in various applications such as surface plasmon resonators, drug delivery systems and electronic optical devices.

  7. Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

    International Nuclear Information System (INIS)

    Garcia, Maria Teresa; Gracia, Ignacio; Duque, Gema; Lucas, Antonio de; Rodriguez, Juan Francisco

    2009-01-01

    Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a 'green process' the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at different temperatures has been investigated. The solvent can be easily recycled by distillation.

  8. Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Choi, Byeong Hyeok; Son, Sang Wook; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon

    2011-01-01

    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 TiO 2 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 TiO 2 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.

  9. Effects of gamma irradiation on food contact polyethylene, polypropylene and polystyrene. Volatiles

    International Nuclear Information System (INIS)

    Kawamura, Yoko; Sayama, Kayo; Yamada, Takashi

    2000-01-01

    The effects of gamma irradiation on the generation of volatiles from food contact polyethylene and polypropylene were investigated using head space (HS)/GC/MS. All samples generated volatiles such as acetic acid, propionic acid, butanoic acid, 2,2-dimethylpropionic acid, acetone, 2-butanone, 2-propanol, 2-methyl-2-propanol, hydrocarbons, etc., due to the gamma irradiation. Especially, acetic acid and acetone were formed in greatest amounts. Since these volatiles did not exist before irradiation and their amounts increased with increasing irradiation dose, they should be degradation products from the polymer or additives by irradiation. Polypropylene generated more kinds and larger amounts of volatiles than polyethylene, which showed that polypropylene is more sensitive to irradiation. Polystyrene contained styrene and ethylbenzene as monomers before irradiation and their amounts decreased after irradiation. Polystyrene generated few degradation products during the irradiation. (author)

  10. The impact of fluorescent dyes on the performances of polystyrene-based plastic scintillators

    International Nuclear Information System (INIS)

    Zhu, Jun; Deng, Cheng; Jiang, Huimin; Zheng, Zhanlong; Gong, Rui; Bi, Yutie; Zhang, Lin; Lin, Runxiong

    2016-01-01

    To investigate the influence of both the first luminescent additive and the wavelength-shifter on the performance of plastic scintillator, a series of polystyrene-based scintillator had been prepared by thermal polymerization. Three first luminescent additives (PPO, p-TP and b-PBD) and four wavelength-shifters (POPOP, Bis-MSB, Me-MSB and DPA) were added to the scintillators respectively. The comparison results showed that PPO and POPOP were the most adequate fluorescent dyes for the polystyrene-based plastic scintillator. Moreover, with the increase of the concentration of PPO and POPOP, the fluorescence intensity and light yield were increased firstly and then decreased. The plastic scintillator containing 2% PPO and 0.02% POPOP had the highest fluorescence intensity and light yield.

  11. Polystyrene/magnesium hydroxide nanocomposite particles prepared by surface-initiated in-situ polymerization

    International Nuclear Information System (INIS)

    Liu Hui; Yi Jianhong

    2009-01-01

    In order to avoid their agglomeration and incompatibility with hydrophobic polystyrene substrate, magnesium hydroxide nanoparticles were encapsulated by surface-initiated in-situ polymerization of styrene. The process contained two steps: electrostatic adsorption of initiator and polymerization of monomer on the surface of magnesium hydroxide. It was found that high adsorption ratio in the electrostatic adsorption of initiator could be attained only in acidic region, and the adsorption belonged to typical physical process. Compared to traditional in-situ polymerization, higher grafting ratio was obtained in surface-initiated in-situ polymerization, which can be attributed to weaker steric hindrance. Both Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) indicated that polystyrene/magnesium hydroxide nanocomposite particles had been successfully prepared by surface-initiated in-situ polymerization. The resulting samples were also analyzed and characterized by means of contact angle testing, dispersibility evaluation and thermogravimetric analysis

  12. Effects of gamma irradiation on food contact polyethylene, polypropylene and polystyrene: additives and other chemicals

    International Nuclear Information System (INIS)

    Kawamura, Yoko; Sayama, Kayo; Yamada, Takashi

    2000-01-01

    The effects of gamma irradiation on additives, oligomers, and other chemicals in food contact polyethylene, polypropylene and polystyrene were investigated. Polyethylene and polypropylene products contained several antioxidants, lubricants and plasticizers. After gamma irradiation, the contents of all the antioxidants significantly decreased. Irgafos 168 disappeared the fastest. Lubricants and plasticizers decreased to some extent or not at all. 2,4-Di-tert-butylphenol was detected not only after irradiation but also before irradiation, and 1,3-di-tert-butylbenzene and 2,6-di-tert-butyl-1,4-benzoquinone were detected only after irradiation. They were presumed to be degradation products of the irradiation, though the former should be also a degradation product of the manufacturing process. On the other hand, the polystyrene products contained styrene dimers and trimers and their contents did not change after the gamma irradiation. (author)

  13. Effects of the alkylamine functionalization of graphene oxide on the properties of polystyrene nanocomposites

    Science.gov (United States)

    Jang, Jinhee; Pham, Viet Hung; Rajagopalan, Balasubramaniyan; Hur, Seung Hyun; Chung, Jin Suk

    2014-05-01

    Alkylamine-functionalized graphene oxides (FGOs) have superior dispersibility in low-polar solvents and, as a result, they interact with low-polar polymers such as polystyrene. In this work, the functionalization of graphene oxide using three types of alkylamines, octylamine (OA), dodecylamine (DDA), and hexadecylamine (HDA), was performed, and nanocomposites of polystyrene (PS) and FGOs were prepared via solution blending. Different dispersions of FGOs over PS were obtained for the three alkylamines, and the properties of the PS composites were influenced by the length of the alkylamine. A better thermal stability was observed with a longer chain length of the alkylamine. On the other hand, functionalization with the shortest chain length alkylamine resulted in the highest increase in the storage modulus (3,640 MPa, 140%) at a 10 wt.% loading of FGO.

  14. Effects of water on starch-g-polystyrene and starch-g-poly(methyl acrylate) extrudates

    International Nuclear Information System (INIS)

    Henderson, A.M.; Rudin, A.

    1982-01-01

    Polystyrene and poly(methyl acrylate) were grafted onto wheat starch by gamma radiation and chemical initiation, respectively. The respective percent add-on values were 46 and 45; 68% of the polystyrene formed was grafted to starch, and corresponding proportion of poly(methyl acrylate) was 41%. The molecular weight distributions of the homopolymer and graft portions were characterized, and extrusion conditions were established for production of ribbon samples of starch-g-PS and starch-g-PMA. Both copolymer types were considerably weakened by soaking in water, and this effect was more immediate and drastic for starch-g-poly(methyl acrylate). Both graft copolymers regained their original tensile strengths on drying, but the poly(methyl acrylate) specimens did not recover their original unswollen dimensions and retained high breaking elongations characteristic of soaked specimens. Tensile and dynamic mechanical properties of extruded and molded samples of both graft polymers are reported, and plasticizing effects of water are summarized

  15. 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

    and ethylenediaminetetraacetic acid (EDTA), as well as adsorption performed at different pH and ionic strength indicates that the high adsorption is caused by electrostatic interaction between negatively charged carboxylate groups on the TCPS surface and positively charged histidine residues in the proteins. Pre......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...

  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. A proton-conducting composite membrane: Sn0.95Al0.05P2O7 and polystyrene-b-poly(ethylene/propylene)-b-polystyrene

    International Nuclear Information System (INIS)

    Jin, Yongcheng; Hibino, Takashi

    2010-01-01

    An anhydrous proton conductor, Sn 0.95 Al 0.05 P 2 O 7 (SAPO), composed of polystyrene-b-poly(ethylene/propylene)-b-polystyrene (SEPS), was developed and characterized using morphological, structural, and electrochemical analyses. In the composite membrane with 20 wt% SEPS, a homogeneous distribution of SAPO particles in the matrix was obtained in the thickness range of 65-90 μm, yielding a proton conductivity of 3.4 x 10 -3 S cm -1 at 200 o C, tensile strength of 4.6 MPa and an elongation at break of 711.0% at room temperature. Fuel cell tests verified that the open-circuit voltage was maintained at a constant value of approximately 1 V between 100 and 250 o C. The peak power densities achieved with unhumidified H 2 and air were 77.0 mW cm -2 at 100 o C, 121.0 mW cm -2 at 150 o C, and 163.1 mW cm -2 at 225 o C.

  18. Improved compatibility between polystyrene and poly(vinylidene fluoride) by the addition of urea

    International Nuclear Information System (INIS)

    Melad, O.; Teim, O.A.; Sobeh, E.

    2005-01-01

    The viscosity behavior of dilute urea solution of dimethylformamide (Dmf) of Polystyrene-Poly(vinylidene fluoride) has been studied at 25 degree C. The results show that the polymer mixtures are incompatible in DMF solution in the absence of urea. The influence of urea addition on the degree of compatibility of the polymer mixture has been studied in terms of the compatibility parameters (A6/M, kbm , A [77] ,a and /?) respectively

  19. Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

    Directory of Open Access Journals (Sweden)

    Xacobe C. Cambeiro

    2011-10-01

    Full Text Available The application of polystyrene-immobilized proline-based catalysts in packed-bed reactors for the continuous-flow, direct, enantioselective α-aminoxylation of aldehydes is described. The system allows the easy preparation of a series of β-aminoxy alcohols (after a reductive workup with excellent optical purity and with an effective catalyst loading of ca. 2.5% (four-fold reduction compared to the batch process working at residence times of ca. 5 min.

  20. Polystyrene Backbone Polymers Consisting of Alkyl-Substituted Triazine Side Groups for Phosphorescent OLEDs

    OpenAIRE

    Salert, Beatrice Ch. D.; Wedel, Armin; Grubert, Lutz; Eberle, Thomas; Anémian, Rémi; Krueger, Hartmut

    2012-01-01

    This paper describes the synthesis of new electron-transporting styrene monomers and their corresponding polystyrenes all with a 2,4,6-triphenyl-1,3,5-triazine basic structure in the side group. The monomers differ in the alkyl substitution and in the meta-/paralinkage of the triazine to the polymer backbone. The thermal and spectroscopic properties of the new electron-transporting polymers are discussed in regard to their chemical structures. Phosphorescent OLEDs were prepared using the obta...

  1. The influence of ultrasonic waves on molecular structure of high impact polystyrene solutions in different solvents

    International Nuclear Information System (INIS)

    Al-Asaly, S.I.

    1991-01-01

    The aim of the this research is to study some physical properties of polymer solutions of high-impact polystyrene (HIPS) solutions in two different solvents (carbon tetrachloride, xylene) by using ultrasonic technique. Absorption coefficient and velocity of ultrasonic waves through different concentrations of these solutions were measured using ultrasonic pulsed generator at constant frequency (800) KHz. The result implies that there is no chemical interaction between (HIPS) molecules and the solvents. 5 tabs.; 18 figs.; 59 refs

  2. Effects of water soaking and/or sodium polystyrene sulfonate addition on potassium content of foods

    OpenAIRE

    Picq, Christian; Asplanato, M.; Bernillon, N.; Fabre, C.; Roubeix, M.; Ricort, J. M.

    2014-01-01

    In this study, we determined, by atomic absorption spectrophotometry, the potassium amount leached by soaking or boiling foods identified by children suffering from chronic renal failure as "pleasure food'' and that they cannot eat because of their low-potassium diet, and evaluated whether addition of sodium polystyrene sulfonate resin (i.e. Kayexalate (R)) during soaking or boiling modulated potassium loss. A significant amount of potassium content was removed by soaking (16% for chocolate a...

  3. Manufacture of Strand Board Bonded with Disposal Expanded Polystyrene as Binder

    OpenAIRE

    Hermawan, Andi; Ohuchi, Takeshi; Fujimoto, Noboru; 大内, 毅; 藤本, 登留

    2010-01-01

    The objective of this study was to evaluate the physical and mechanical properties of strand board bonded with disposal expanded polystyrene (EPS) as binder. The strand board was manufactured using strand made from Douglas-fir beams selected from construction scrap wood. The strands were oriented, and two types of three-layer (face-core-face) strand board were manufactured: one in which the board bounded with only disposal EPS (P board), and the other in which the board bonded with disposal...

  4. Structure and properties of binary polystyrene-epoxy acrylate oligomer mixtures irradiated by electron beams

    International Nuclear Information System (INIS)

    Lomonosova, N.V.

    1995-01-01

    The change in the structure of oriented polymer-oligomer systems based on polystyrene (PS) with M > 10 6 and epoxy acrylate oligomers (aliphatic and aromatic) under irradiation by accelerated electrons was studied using birefringence, isometric heating, IR dichroism, and thermooptical analysis. Mechanical properties of these systems were investigated. It was found that, by adding aliphatic epoxy acrylate to PS and further irradiating this mixture, one can obtain both isotropic and oriented composites with higher strengths, elasticity moduli, and glass transition temperatures

  5. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  6. Investigation and computer modeling of radiation and thermal decomposition of polystyrene scintillators

    Science.gov (United States)

    Sakhno, Tamara V.; Pustovit, Sergey V.; Borisenko, Artem Y.; Senchishin, Vitaliy G.; Barashkov, Nikolay N.

    2003-12-01

    This paper is devoted to the investigation and computer modeling of radiation and thermal decomposition of luminescent polystyrene compositions. It has been shown, that the stability of the optical properties of luminescent polymer composition depends on its material structure. On the basis of quantum-chemical calculation has been obtained the possible products of PS gamma-radiolysis and the effect of formation of fragments with conjugated double bonds and products with quinone structure has been investigated.

  7. Immobilization of Glucose Oxidase to Nanostructured Films of Polystyrene-block-poly(2-vinylpyridine)

    OpenAIRE

    Bhakta, Samir A; Benavidez, Tomas E; Garcia, Carlos D

    2014-01-01

    A critical step for the development of biosensors is the immobilization of the biorecognition element to the surface of a substrate. Among other materials that can be used as substrates, block copolymers have the untapped potential to provide significant advantages for the immobilization of proteins. To explore such possibility, this manuscript describes the fabrication and characterization of thin-films of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP). These films were then used to inv...

  8. 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

  9. Synthesis of side-chain polystyrenes for all organic solution processed OLEDs

    OpenAIRE

    Lorente Sánchez, Alejandro Jose (Dr.)

    2017-01-01

    In the present work side-chain polystyrenes were synthesized and characterized, in order to be applied in multilayer OLEDs fabricated by solution process techniques. Manufacture of optoelectronic devices by solution process techniques is meant to decrease significantly fabrication cost and allow large scale production of such devices. This dissertation focusses in three series, enveloped in two material classes. The two classes differ to each other in the type of charge transport exhibited...

  10. Tritium-doping enhancement of polystyrene by ultraviolet laser and hydrogen plasma irradiation for laser fusion experiments

    Energy Technology Data Exchange (ETDEWEB)

    Iwasa, Yuki, E-mail: iwasa-y@ile.osaka-u.ac.jp [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yamanoi, Kohei; Iwano, Keisuke; Empizo, Melvin John F.; Arikawa, Yasunobu; Fujioka, Shinsuke; Sarukura, Nobuhiko; Shiraga, Hiroyuki; Takagi, Masaru; Norimatsu, Takayoshi; Azechi, Hiroshi [Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Noborio, Kazuyuki; Hara, Masanori; Matsuyama, Masao [Hydrogen Isotope Research Center, Organization for Promotion of Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

    2016-11-15

    Highlights: • Tritium-doped polystyrene films are fabricated by the Wilzbach method with UV laser and hydrogen plasma irradiation. • The 266-nm laser-irradiated, 355-nm laser-irradiated, and hydrogen plasma-irradiated polystyrene films exhibit higher PSL intensities and specific radioactivities than the non-irradiated sample. • Tritium doping by UV laser irradiation can be largely affected by the laser wavelength because of polystyrene’s absorption. • Hydrogen plasma irradiation results to a more uniform doping concentration even at low partial pressure and short irradiation time. • UV laser and plasma irradiations can be utilized to fabricate tritium-doped polystyrene shell targets for future laser fusion experiments. - Abstract: We investigate the tritium-doping enhancement of polystyrene by ultraviolet (UV) laser and hydrogen plasma irradiation. Tritium-doped polystyrene films are fabricated by the Wilzbach method with UV laser and hydrogen plasma. The 266-nm laser-irradiated, 355-nm laser-irradiated, and hydrogen plasma-irradiated polystyrene films exhibit higher PSL intensities and specific radioactivities than the non-irradiated sample. Tritium doping by UV laser irradiation can be largely affected by the laser wavelength because of polystyrene’s absorption. In addition, UV laser irradiation is more localized and concentrated at the spot of laser irradiation, while hydrogen plasma irradiation results to a more uniform doping concentration even at low partial pressure and short irradiation time. Both UV laser and plasma irradiations can nevertheless be utilized to fabricate tritium-doped polystyrene targets for future laser fusion experiments. With a high doping rate and efficiency, a 1% tritium-doped polystyrene shell target having 7.6 × 10{sup 11} Bq g{sup −1} specific radioactivity can be obtained at a short period of time thereby decreasing tritium consumption and safety management costs.

  11. Thermodynamic and Kinetic Behavior of the Polystyrene/Poly(vinyl methyl ether) Blend as Studied by Excimer Fluorescence.

    Science.gov (United States)

    1986-01-02

    AD-A±63 895 THERMODYNAMIC AND KINETIC BEHAVIOR OF THE / POLYSTYRENE/POLY(YINYL METHYL E..(U) STANFORD UNIY CALIFDEPT OF CHEMICAL ENGINEERING C N...Polystyrene/Poly(vinyl methyl ether) Blend 7. DEcFRMN 81 toOR 30USptE8 00~ as Studied by Excimer Fluorescence 6 EFRIGOG EOTNME *AUTHOR() a. CONTRACT OR GRANT...werea fondoare ihemoriisof * ~ Ex e sp fluodecositionsdu to deud Gen e and hoog Pinus Florsneis shownhase migrationprocSECURITY CLASIFICTIO OFd

  12. 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.

  13. Rapid and low-cost fabrication of polystyrene-based molds for PDMS microfluidic devices using a CO2 laser

    KAUST Repository

    Li, Huawei; Fan, Yiqiang; Foulds, Ian G.

    2011-01-01

    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.

  14. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    Science.gov (United States)

    Liu, Huiyu; Chen, Dong; Tang, Fangqiong; Du, Gangjun; Li, Linlin; Meng, Xianwei; Liang, Wei; Zhang, Yangde; Teng, Xu; Li, Yi

    2008-11-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm-2) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  15. The Role of Mucin in the Toxicological Impact of Polystyrene Nanoparticles

    Directory of Open Access Journals (Sweden)

    Iwona Inkielewicz-Stepniak

    2018-05-01

    Full Text Available The development of novel oral drug delivery systems is an expanding area of research and both new approaches for improving their efficacy and the investigation of their potential toxicological effect are crucial and should be performed in parallel. Polystyrene nanoparticles (NPs have been used for the production of diagnostic and therapeutic nanosystems, are widely used in food packaging, and have also served as models for investigating NPs interactions with biological systems. The mucous gel layer that covers the epithelium of the gastrointestinal system is a complex barrier-exchange system that it is mainly constituted by mucin and it constitutes the first physical barrier encountered after ingestion. In this study, we aimed to investigate the effect of polystyrene NPs on mucin and its potential role during NP–cell interactions. For this purpose, we evaluated the interaction of polystyrene NPs with mucin in dispersion by dynamic light scattering and with a deposited layer of mucin using a quartz crystal microbalance with dissipation technology. Next, we measured cell viability and the apoptotic state of three enterocyte-like cell lines that differ in their ability to produce mucin, after their exposure to the NPs. Positive charged NPs showed the ability to strongly interact and aggregate mucin in our model. Positive NPs affected cell viability and induced apoptosis in all cell lines independently of their ability of produce mucin.

  16. 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.

  17. Electrospinning fabrication and oxygen sensing properties of Cu(I) complex-polystyrene composite microfibrous membranes

    International Nuclear Information System (INIS)

    Wang Liyan; Xu Yun; Lin Zhu; Zhao Ning; Xu Yanhua

    2011-01-01

    In this paper, a phosphorescent Cu(I) complex of [Cu(POP)(ECI-Phen)]BF 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 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: → Cu(I) complex is incorporated into polystyrene matrix to form nanofibers. → Resulted sample exhibit good linearity and short response time. → PS is an excellent matrix for oxygen sensing material for probe molecules. → Molecular structure of diamine ligand is critical for sensitivity.

  18. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications.

    Science.gov (United States)

    Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; Mitchell, Micki; Burke, Micheal; Quinn, Aidan J; O'Riordan, Alan

    2014-05-02

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 10(6), in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated.

  19. Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications

    International Nuclear Information System (INIS)

    Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; Mitchell, Micki; Burke, Micheal; Quinn, Aidan J; O’Riordan, Alan

    2014-01-01

    In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 10 6 , in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated. (paper)

  20. Long-term clearance of inhaled magnetite and polystyrene latex from the lung: a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, R.B.; Halpern, M.; Lippmann, M. (New York Univ., NY (USA). Inst. of Environmental Medicine)

    1982-01-01

    As part of a larger study evaluating the applicability of a magnetic detection technique for monitoring lung retention of inhaled particles, simultaneous radiological measurements of the retention of magnetite and polystyrene latex particles in four donkeys were performed. The radiometric measurements were performed using a scintillation detector series modified for separation of the higher energy ..gamma..-emissions of /sup 59/Fe and /sup 85/Sr. In all animals, after 24 hr post-exposure, both polystyrene and magnetite exhibited a relatively rapid phase for 80 days (Tsub(1/2) = 15-22 days) which, in three donkeys, was clearly followed by a slower phase (Tsub(1/2) = 42-173 days); activity levels after 80 days in the fourth donkey were too low to permit determination of clearance rate. During the second phase, a deviation in pattern was clearly observed between the two aerosols, the polystyrene being cleared consistently faster than the magnetite. It is suggested that this deviation implies that, beginning at this time, there were functional differences between the dominant clearance mechanisms for the two aerosols. Exactly what these mechanisms were, or whether the difference was attributable to specific differences in particle characteristics, could not be determined.

  1. Long-term clearance of inhaled magnetite and polystyrene latex from the lung: a comparison

    International Nuclear Information System (INIS)

    Schlesinger, R.B.; Halpern, M.; Lippmann, M.

    1982-01-01

    As part of a larger study evaluating the applicability of a magnetic detection technique for monitoring lung retention of inhaled particles, simultaneous radiological measurements of the retention of magnetite and polystyrene latex particles in four donkeys were performed. The radiometric measurements were performed using a scintillation detector series modified for separation of the higher energy γ-emissions of 59 Fe and 85 Sr. In all animals, after 24 hr post-exposure, both polystyrene and magnetite exhibited a relatively rapid phase for 80 days (Tsub(1/2) = 15-22 days) which, in three donkeys, was clearly followed by a slower phase (Tsub(1/2) = 42-173 days); activity levels after 80 days in the fourth donkey were too low to permit determination of clearance rate. During the second phase, a deviation in pattern was clearly observed between the two aerosols, the polystyrene being cleared consistently faster than the magnetite. It is suggested that this deviation implies that, beginning at this time, there were functional differences between the dominant clearance mechanisms for the two aerosols. Exactly what these mechanisms were, or whether the difference was attributable to specific differences in particle characteristics, could not be determined. (U.K.)

  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. Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

    International Nuclear Information System (INIS)

    Liu Huiyu; Chen Dong; Tang Fangqiong; Li Linlin; Meng Xianwei; Li Yi; Du Gangjun; Liang Wei; Zhang Yangde; Teng Xu

    2008-01-01

    A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm -2 ) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

  4. Synthesis of Ag-coated polystyrene colloids by an improved surface seeding and shell growth technique

    International Nuclear Information System (INIS)

    Tian Chungui; Wang Enbo; Kang Zhenhui; Mao Baodong; Zhang Chao; Lan Yang; Wang Chunlei; Song Yanli

    2006-01-01

    In this paper, an improved surface seeding and shell growth technique was developed to prepare Ag-polystyrene core shell composite. Polyethyleneimine (PEI) could act as the linker between Ag ions (Ag nanoparticles) and polystyrene (PS) colloids and the reducing agent in the formation of Ag nanoparticles. Due to the multi-functional characteristic of PEI, Ag seeds formed in-situ and were immobilized on the surface of PEI-modified PS colloids and no free Ag clusters coexist with the Ag 'seeding' PS colloids in the system. Then, the additional agents could be added into the resulting dispersions straightly to produce a thick Ag nanoshell. The Ag nanoshell with controllable thickness was formed on the surface of PS by the 'one-pot' surface seeding and shell growth method. The Ag-coverage increased gradually with the increasing of mass ratio of AgNO 3 /PS. The optical properties of the Ag-PS colloids could be tailored by changing the coverage of Ag. - Graphical abstract: An improved surface seeding and shell growth technique was developed to prepare Ag-polystyrene core shell composite. The optical properties of the Ag-PS colloids could be tailored by changing the coverage of Ag. Display Omitted

  5. Polystyrene tube radioimmunoabsorbent assay for IgE anti-penicillin antibody

    International Nuclear Information System (INIS)

    Urena, V.; Delgado, R.G.; Daroca, P.; Lahoz, C.

    1977-01-01

    A radioimmunoassay technique has been developed based on the binding capacity of polystyrene for proteins. The method was tested on sera from thirteen patients with suspected penicillin allergy, five healthy controls, and three patients with seasonal pollen reactions. The results were compared with those obtained by the radio-allergoabsorbent method (RAST) and with basophil degranulation by penicillin. A penicillin/ovalbumin conjugate (pen-OA) was prepared and polystyrene tubes were incubated with pen-OA, 3% human serum albumin to block free sites, 1/10 dilution of test serum, anti-IgE antiserum specific for epsilon chains, and 125 I-IgE. The tubes were washed after the incubation period and the empty tubes counted in a γ scintillation counter. The specificity of the method was tested by an inhibition assay. The technique seemed more sensitive than the RAST method, the results were reproducible and in general showed good correlation with those of the RAST method. This polystyrene tube radioimmunoabsorbent method therefore provides a simple, specific and sensitive diagnostic technique for penicillin allergy. (U.K)

  6. 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.

  7. Polystyrene nanoparticles facilitate the internalization of impermeable biomolecules in non-tumour and tumour cells from colon epithelium

    International Nuclear Information System (INIS)

    Cabeza, Laura; Cano-Cortés, Victoria; Rodríguez, María J.; Vélez, Celia; Melguizo, Consolación; Sánchez-Martín, Rosario M.; Prados, Jose

    2015-01-01

    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

  8. The surface pressure dynamics and appearance of mixed monolayers of cholesterol and different sized polystyrenes at an air-water interface.

    Science.gov (United States)

    Mudgil, Poonam; Dennis, Gary R; Millar, Thomas J

    2005-02-15

    Synthetic polymers are increasingly being used in situations where they are designed to interact with biological systems. As a result, it is important to investigate the interactions of the polymers with biochemicals. We have used cholesterol, as an example of an important biological surfactant component, to study its interactions with polystyrene. Mixed monolayers of cholesterol and one of two different molecular weight polystyrenes were formed at an air-water interface to investigate their interactions and to determine whether the size of the polystyrene affected the interaction. The pressure-area (pi-A) isocycles of mixed monolayers of cholesterol and polystyrene MW 2700 or polystyrene MW32700 showed that strongest attractive interactions occur at high surface pressures and in polystyrene rich films. The excess area and excess free energy of mixing were most negative at high surface pressures and at high mole fraction of polystyrene. The most stable mixed monolayers were formed with X(PS2700) = 0.9 and X(PS32700) = 0.09. Microscopic observation of the mixed monolayers of cholesterol and polystyrene showed the formation of stable islands in the cholesterol/polystyrene mixtures. These observations, the nature of the inflection points in the isocycles, and the anomalous changes in free energy lead us to conclude that there is a stable rearrangement of polystyrene into compact islands when it is mixed with cholesterol. Any excess cholesterol is excluded from these islands and remains as a separate film surrounding the islands.

  9. 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.

  10. Influence of polystyrene addition to cellulose on chemical structure and properties of bio-oil obtained during pyrolysis

    International Nuclear Information System (INIS)

    Rutkowski, Piotr; Kubacki, Andrzej

    2006-01-01

    The cellulose (C), polystyrene (PS) and cellulose/polystyrene (C-PS) mixtures (3:1, 1:1, 1:3 w/w) were subjected to a pyrolysis process to produce bio-oil. The pyrolytic oil yield was in the range of 45.5-94.8 wt% depending on the composition of the sample. Pyrolysis of polystyrene gives the highest oil yield, whereas for cellulose, the yield of liquid products was the lowest. The basic physicochemical properties of oils are strongly influenced by the original material and do not change additively. The polystyrene addition to cellulose clearly improves the quality of the bio-oil, resulting in decreases in acid number, pour point and density. The change of color is not so distinct. The FT-IR analysis of the oils showed that the oxygen functionalities and hydrocarbons contents highly depend on the composition of the cellulose/polystyrene mixture. The fractionation of bio-oils by column chromatography using hexane and benzene was followed by GC-MS analyses. Different classes of organic compounds were identified, i.e., carboxylic acids, phenols, aldehydes, ketones, esters, ethers and unsaturated linear and cyclic hydrocarbons. The proportion of hydrocarbons increases with a decrease of the cellulose/polystyrene ratio. The obtained results indicate that during pyrolysis, not only does decomposition of cellulose and polystyrene occur, but also, reactions between products from C and PS take place. That was proved by the presence of compounds identified only in the bio-oils obtained from C-PS compositions

  11. 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.

  12. Echicetin Coated Polystyrene Beads: A Novel Tool to Investigate GPIb-Specific Platelet Activation and Aggregation

    Science.gov (United States)

    Petunin, Alexey; Clemetson, Kenneth J.; Gambaryan, Stepan; Walter, Ulrich

    2014-01-01

    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. PMID:24705415

  13. Organic nanostructures on silicon, created with semitransparent polystyrene spheres and 248 nm laser pulses

    International Nuclear Information System (INIS)

    Rothe, Erhard W; Manke, Charles W; Piparia, Reema; Baird, Ronald J

    2008-01-01

    Arrays of nanostructures are made starting with a template of close-packed, polystyrene spheres on a silicon surface. The spheres are either 1.091 or 2.99 μm in diameter (d) and are of polystyrene (PS). They are irradiated with a pulse of either 308 or 248 nm light to which they are transparent and semitransparent, respectively. A transparent sphere with d = 1.091 μm diameter concentrates incident light onto a small substrate area. As has been previously reported, that creates silicon nanobumps that rise from circular craters. At 248 nm and d = 2.99 μm, the light energy is mainly absorbed, destroys the sphere, and leaves a shrunken mass (typically about 500 nm wide and 100 nm high) of organic material that is probably polystyrene and its thermal degradation products. At 248 nm and d = 1.091 μm, the residual organic structures are on the order of 300 nm wide and 100 nm high. A distinctive feature is that these organic structures are connected by filaments that are on the order of 50 nm wide and 10 nm high. Filaments form because the close-packed PS spheres expand into each other during the early part of the laser pulse, and then, as the main structures shrink, their viscoelasticity leads to threads between them. Our results with 248 nm and d = 1.091 μm differ from those described by Huang et al with 248 nm and d = 1.0 μm. Future studies might include the further effect of wavelength and fluence upon the process as well the use of other materials and the replacement of nanospheres by other focusing shapes, such as ellipsoids or rods

  14. Non-conductive ferromagnetic carbon-coated (Co, Ni) metal/polystyrene nanocomposites films

    Energy Technology Data Exchange (ETDEWEB)

    Takacs, H., E-mail: helene.takacs@gmail.com [CEA, LETI, MINATEC Campus, Grenoble 38054 (France); LTM-CNRS-UJF, CEA, LETI, Minatec Campus, Grenoble 38054 (France); Viala, B.; Hermán, V. [CEA, LETI, MINATEC Campus, Grenoble 38054 (France); Tortai, J.-H. [LTM-CNRS-UJF, CEA, LETI, Minatec Campus, Grenoble 38054 (France); Duclairoir, F. [Université Grenoble Alpes, INAC, Grenoble 38054 (France); CEA, INAC, Grenoble 38054 (France)

    2016-03-07

    This article reports non-conductive ferromagnetic properties of metal/polymer nanocomposite films intended to be used for RF applications. The nanocomposite arrangement is unique showing a core double-shell structure of metal-carbon-polystyrene: M/C//P{sub 1}/P{sub 2}, where M = Co, Ni is the core material, C = graphene or carbon is the first shell acting as a protective layer against oxidation, P{sub 1} = pyrene-terminated polystyrene is the second shell for electrical insulation, and P{sub 2} = polystyrene is a supporting matrix (// indicates actual grafting). The nanocomposite formulation is briefly described, and the film deposition by spin-coating is detailed. Original spin-curves are reported and analyzed. One key outcome is the achievement of uniform and cohesive films at the wafer scale. Structural properties of films are thoroughly detailed, and weight and volume fractions of M/C are considered. Then, a comprehensive overview of DC magnetic and electrical properties is reported. A discussion follows on the magnetic softness of the nanocomposites vs. that of a single particle (theoretical) and the raw powder (experimental). Finally, unprecedented achievement of high magnetization (∼0.6 T) and ultra-high resistivity (∼10{sup 10 }μΩ cm) is shown. High magnetization comes from the preservation of the existing protective shell C, with no significant degradation on the particle net-moment, and high electrical insulation is ensured by adequate grafting of the secondary shell P{sub 1}. To conclude, the metal/polymer nanocomposites are situated in the landscape of soft ferromagnetic materials for RF applications (i.e., inductors and antennas), by means of two phase-diagrams, where they play a crucial role.

  15. Development of simple immunoradiometric assays using avidin coupled to polystyrene beads as a common solid phase

    International Nuclear Information System (INIS)

    Jyotsna, N.; Singh, Y.; Chouthkanthiwar, V.; Paradkar, S.; Sivaprasad, N.

    1998-01-01

    In this paper, we describe the preparation and application of avidin coupled polystyrene beads as a common solid phase for use in immunoradiometric assays (IRMAs). The assay system is based on two matched commercial monoclonal antibodies, of which, the capture antibody is biotinylated using biotinamidocaproate N-hydroxysuccinimide ester and the detection antibody is radiolabeled with 125 I by conventional Chloramine-T method. Avidin was immobilized on the polystyrene beads through a primary coat of bovine serum albumin using glutaraldhyde activation method. Various factors, such as concentration of reagents, incubation time, etc. were optimised to obtain a simple assay protocol consisting of only two pipetting steps, namely, that of a mixture of the two labelled antibodies (radiolabelled and biotinylated) and of the standard or sample. The advantage of the Avidin-Biotin system is the improved sensitivity, economy of antibody and the possibility to use a common solid phase in assays for different analytes. Using the polystyrene beads along with the novel decanting device, it has been possible to achieve the convenience of the 'coated-tube' technology without the expensive automation necessary for large scale preparation of antibody coated tubes. This protocol has been successfully applied to Prolactin, LH and FSH assays. The sensitivity of the Prolactin assay is 8μIU/mL (0.3 ng/mL), that of the FSH assay is 1mIU/mL and that of the LH assay is 0.9 mIU/mL. The intra-assay and inter-assay variations were <10%. Shelf life of the avidin coupled beads was found to be about 8 months and that of the biotin labelled antibodies up to 18 months. (author)

  16. 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.

  17. Studies on radiation damage to polystyrene exchanger in different cationic forms

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.; Jagtap, N.B.; Waghmare, S.; Kulkarni, S.A.

    1985-01-01

    Polystyrene divinylbenzene copolymer containing nuclear sulfonic acid functional group and H + , Sr 2+ , Cu 2+ , UO 2 2+ or Al 3+ exchangeable cation was subjected to varying gamma doses to study the effects on its physicochemical properties. The exchange capacity and moisture content decreased, the maximum effect was in the case of Cu ++ form of the resin. The data are explained on the basis of metal oxygen bonding. IR spectra indicated the formation of new exchange sites upon irradiation and disapearance of the original functional groups. (author)

  18. Fabrication and characteristics of self-assembly nano-polystyrene films by laser induced CVD

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Tingting [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Cai, Congzhong [Department of Applied Physics, Chongqing University, Chongqing 401331 (China); Peng, Liping [Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Wu, Weidong, E-mail: wuweidongding@163.com [Science and Technology on Plasma Physics Laboratory, Research Center of Laser Fusion, CAEP, Mianyang 621900 (China)

    2013-10-01

    The self-assembly nano-polystyrene (PS) films have been prepared by laser induced CVD at room temperature. The XPS, Raman and UV–vis absorption spectra all indicated that the films were PS. The optical properties, microstructure and controllable nanostructure of PS films have been investigated. Dewetting-like microstructure in PS films was investigated and uniform island structures with a diameter of about 200 nm were observed at the deposition pressure of 14 Pa. The films possess good toughness and precisely controlled thicknesses. The free-standing PS films with thickness of 10 nm could be obtained by this method though a series of process.

  19. Influence of gamma radiation on antibodies fixation on polystyrene. Application to ELISA enzyme immunoassay

    International Nuclear Information System (INIS)

    Esterlin, S.

    1986-01-01

    This thesis is divided into two parts: the first part includes a description of the ELISA test, a comparative analysis of the main supports (polystyrene microtitration trays) used for this technique and an evaluation of gamma radiation effects on the quality of the supports. The study was carried out with the following antigens: Spiroplasma citri R8A2, a tymovirus and Tristeza virus. The second part dealt with the effects of gamma radiations on antibodies and antibody-support system (interaction immobilized immunoglobulins-plastic support) [fr

  20. Properties of the ukrainian polystyrene-based plastic scintillator UPS 923A

    International Nuclear Information System (INIS)

    Artikov, A.; Budagov, Yu.; Chirikov-Zorin, I.; Lyablin, M.; Chokheli, D.; Bellettini, G.; Mensione, 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 the 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

  1. 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......-dimensional as well as two-dimensional parametric analyses are conducted taking into account static and seismic loading conditions. The interaction of the soil–geofoam–foundation system is taken into consideration. The use of EPS as fill material in foundation systems is proven to be not only technically but also...

  2. Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

    Science.gov (United States)

    Klueh, U; Bryers, J D; Kreutzer, D L

    2003-10-01

    Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36

  3. 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.

  4. Ileocolic perforation secondary to sodium polystyrene sulfonate in sorbitol use: A case report

    Science.gov (United States)

    Trottier, Vincent; Drolet, Sébastien; Morcos, Mohib W

    2009-01-01

    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. PMID:19826644

  5. Shock Hugoniot and temperature data for polystyrene obtained with quartz standard

    International Nuclear Information System (INIS)

    Ozaki, N.; Kimura, T.; Miyanishi, K.; Endo, T.; Sano, T.; Shigemori, K.; Azechi, H.; Hironaka, Y.; Kadono, T.; Nagatomo, H.; Nakai, M.; Norimatsu, T.; Otani, K.; Shiroshita, A.; Sunahara, A.; Ikoma, M.; Hori, Y.; Vinci, T.; Ree, F. H.; Iwamoto, A.

    2009-01-01

    Equation-of-state data, not only pressure and density but also temperature, for polystyrene (CH) are obtained up to 510 GPa. The region investigated in this work corresponds to an intermediate region, bridging a large gap between available gas-gun data below 60 GPa and laser shock data above 500 GPa. The Hugoniot parameters and shock temperature were simultaneously determined by using optical velocimeters and pyrometers as the diagnostic tools and the α-quartz as a new standard material. The CH Hugoniot obtained tends to become stiffer than a semiempirical chemical theoretical model predictions at ultrahigh pressures but is consistent with other models and available experimental data.

  6. Polystyrene-poly(vinylphenol) copolymers as compatibilzers for organic-inorganic composites

    International Nuclear Information System (INIS)

    Landry, C.J.T.; Coltrain, B.K.; Teegarden, D.M.

    1996-01-01

    Random, graft, and block copolymers of polystyrene (PS) and poly(4-vinylphenol) (PVPh), and PVPh homopolymer are shown to act as compatibilizers for incompatible organic-inorganic composite materials. The VPh component reacts, or interacts strongly with the polymerizing inorganic (titanium or zirconium) alkoxide. The organic components studied were PS, poly(vinyl methyl ether), and poly(styrene-co-acrylonitrile). The use of such compatibilizers provides a means of combining in situ polymerized inorganic oxides and hydrophobic polymers. This is seen as a reduction in the size of the dispersed inorganic phase and results in improved optical and mechanical properties

  7. Gamma irradiation of yellow and blue colorants in polystyrene packaging materials

    International Nuclear Information System (INIS)

    Komolprasert, V.; Diel, Todd; Sadler, G.

    2006-01-01

    The effect of 10- and 20-kGy gamma irradiation was studied on chromophtal yellow 2RLTS (Yellow 110-2, 3, 4, 5-tetrachloro-6-cyanobenzoic acid) and Irgalite Blue GBP (copper (II) phthalocyanine blue) colorants, which were added to polystyrene (PS) material used to package food prior to irradiation. Analytical results obtained suggest that irradiation did not generate any new chemicals in the PS polymer containing either yellow or blue colorant at a concentration of up to 1% (w/w). Both yellow and blue colorants are relatively stable to gamma irradiation

  8. 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.

  9. Hardness enhancement and crosslinking mechanisms in polystyrene irradiated with high energy ion-beams

    International Nuclear Information System (INIS)

    Lee, E.H.; Rao, G.R.; Mansur, L.K.

    1996-01-01

    Surface hardness values several times larger than steel were produced using high energy ion beams at several hundred keV to MeV. High LET is important for crosslinking. Crosslinking is studied by analyzing hardness variations in response to irradiation parameter such as ion species, energy, and fluence. Effective crosslinking radii at hardness saturation are derived base on experimental data for 350 keV H + and 1 MeV Ar + irradiation of polystyrene. Saturation value for surface hardness is about 20 GPa

  10. 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.

  11. 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.

  12. Application of methods of mathematical modeling for determining of radiation-protective characteristics of polystyrene-metal composite materials

    International Nuclear Information System (INIS)

    Klepikov, V.F.; Prokhorenko, E.M.; Lytvynenko, V.V.; Zakharchenko, A.A.; Nazhmuradov, M.A.

    2016-01-01

    Radiation safety features of polystyrene steel composite materials were found by means of mathematical modeling techniques. We determined the attenuation of the gamma quantum flux passing through a solid protective layer compared with those attenuation for the bulk protective layer. Change of fractional attenuation of the dose absorbed by 10 and 50 mm thick composites is calculated. Dependence between protective properties of composite and its blend composition was studied. Modifications of technical process of composite materials production were performed. Rotation speed of agitator system was found. It was defined that heating time of polystyrene steel mix is longer than heating time of polystyrene tungstic one. Degree of mix heating and integrity of thermic field on its surface was controlled with the help of IR radiometry methods.

  13. 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.

  14. 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.

  15. 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.

  16. Retardation the dewetting dynamics of ultrathin polystyrene films using highly branched aromatic molecules as additives

    International Nuclear Information System (INIS)

    Pangpaiboon, Nampueng; Traiphol, Nisanart; Promarak, Vinich; Traiphol, Rakchart

    2013-01-01

    This study introduces a new class of materials as a dewetting inhibitor for polystyrene (PS) ultrathin films. Two types of highly branched aromatic (HBA) molecules are added into PS films with thicknesses of 7 nm and 23 nm. Their concentrations range from 0.75 to 5 wt.%. The films are annealed in vacuum oven at elevated temperatures to accelerate dewetting process. Evolution of the film morphologies is followed by utilizing atomic force microscopy and optical microscopy. Contact angle measurements are used to evaluate interfacial interactions in each system. Dewetting area as a function of annealing time and HBA concentration are calculated. We have found that the presence of only 0.5 wt.% HBA can suppress the dewetting dynamics of PS films. Increasing the HBA concentration from 0.5 to 5 wt.% causes systematic decrease of the dewetting rate. In this system, the HBA molecules behave as physical cross-linking points for PS chains, which lead to the improvement of film stability. The efficiency of HBA as a dewetting inhibitor varies with molecular weight of PS while the change of HBA structure hardly affects the dewetting behaviors. - Highlights: • New method for improving stability of polystyrene (PS) thin films • Highly branched aromatic molecules (HBA) are used to suppress the dewetting. • Thermal stability of blended PS/HBA films greatly improves. • The effectiveness of HBA varies with molecular weight of PS. • Important results for designing materials in coating application

  17. Retardation the dewetting dynamics of ultrathin polystyrene films using highly branched aromatic molecules as additives

    Energy Technology Data Exchange (ETDEWEB)

    Pangpaiboon, Nampueng [Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Traiphol, Nisanart, E-mail: Nisanart.T@chula.ac.th [Research Unit of Advanced Ceramics, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Promarak, Vinich [School of Chemistry and Center of Excellence for Innovation in Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Traiphol, Rakchart, E-mail: Rakchartt@nu.ac.th [Laboratory of Advanced Polymers and Nanomaterials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); NANOTEC-MU Excellence Center on Intelligent Materials and Systems, Faculty of Science, Rama 6 Road, Ratchathewi, Bangkok 10400 (Thailand)

    2013-12-02

    This study introduces a new class of materials as a dewetting inhibitor for polystyrene (PS) ultrathin films. Two types of highly branched aromatic (HBA) molecules are added into PS films with thicknesses of 7 nm and 23 nm. Their concentrations range from 0.75 to 5 wt.%. The films are annealed in vacuum oven at elevated temperatures to accelerate dewetting process. Evolution of the film morphologies is followed by utilizing atomic force microscopy and optical microscopy. Contact angle measurements are used to evaluate interfacial interactions in each system. Dewetting area as a function of annealing time and HBA concentration are calculated. We have found that the presence of only 0.5 wt.% HBA can suppress the dewetting dynamics of PS films. Increasing the HBA concentration from 0.5 to 5 wt.% causes systematic decrease of the dewetting rate. In this system, the HBA molecules behave as physical cross-linking points for PS chains, which lead to the improvement of film stability. The efficiency of HBA as a dewetting inhibitor varies with molecular weight of PS while the change of HBA structure hardly affects the dewetting behaviors. - Highlights: • New method for improving stability of polystyrene (PS) thin films • Highly branched aromatic molecules (HBA) are used to suppress the dewetting. • Thermal stability of blended PS/HBA films greatly improves. • The effectiveness of HBA varies with molecular weight of PS. • Important results for designing materials in coating application.

  18. 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.

  19. An efficient hybrid, nanostructured, epoxidation catalyst: titanium silsesquioxane-polystyrene copolymer supported on SBA-15.

    Science.gov (United States)

    Zhang, Lei; Abbenhuis, Hendrikus C L; Gerritsen, Gijsbert; Bhriain, Nollaig Ní; Magusin, Pieter C M M; Mezari, Brahim; Han, Wei; van Santen, Rutger A; Yang, Qihua; Li, Can

    2007-01-01

    A novel interfacial hybrid epoxidation catalyst was designed with a new immobilization method for homogeneous catalysts by coating an inorganic support with an organic polymer film containing active sites. The titanium silsesquioxane (TiPOSS) complex, which contains a single-site titanium active center, was immobilized successfully by in-situ copolymerization on a mesoporous SBA-15-supported polystyrene polymer. The resulting hybrid materials exhibit attractive textural properties (highly ordered mesostructure, large specific surface area (>380 m2 g-1) and pore volume (>or==0.46 cm3 g-1)), and high activity in the epoxidation of alkenes. In the epoxidation of cyclooctene with tert-butyl hydrogen peroxide (TBHP), the hybrid catalysts have rate constants comparable with that of their homogeneous counterpart, and can be recycled at least seven times. They can also catalyze the epoxidation of cyclooctene with aqueous H2O2 as the oxidant. In two-phase reaction media, the catalysts show much higher activity than their homogeneous counterpart due to the hydrophobic environment around the active centers. They behave as interfacial catalysts due to their multifunctionality, that is, the hydrophobicity of polystyrene and the polyhedral oligomeric silsesquioxanes (POSS), and the hydrophilicity of the silica and the mesoporous structure. Combination of the immobilization of homogeneous catalysts on two conventional supports, inorganic solid and organic polymer, is demonstrated to achieve novel heterogeneous catalytic ensembles with the merits of attractive textural properties, tunable surface properties, and optimized environments around the active sites.

  20. A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

    International Nuclear Information System (INIS)

    Kuo, Wen-Kai; Weng, Hsueh-Ping; Hsu, Jyun-Jheng; Yu, Hsin Her

    2016-01-01

    Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

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

    Science.gov (United States)

    Holmberg, Maria; Hansen, Thomas Steen; Lind, Johan Ulrik; Hjortø, Gertrud Malene

    2012-04-01

    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 and ethylenediaminetetraacetic acid (EDTA), as well as adsorption performed at different pH and ionic strength indicates that the high adsorption is caused by electrostatic interaction between negatively charged carboxylate groups on the TCPS surface and positively charged histidine residues in the proteins. Pre-adsorption of bovine serum albumin (BSA) does not decrease the adsorption of HIS-tagged proteins onto TCPS. Our findings identify a potential problem in using HIS-tagged signalling molecule in assays with cells cultured on TCPS, since the concentration of the molecule in solution might be affected and this could critically influence the assay outcome. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Interfacial free energy governs single polystyrene chain collapse in water and aqueous solutions.

    Science.gov (United States)

    Li, Isaac T S; Walker, Gilbert C

    2010-05-12

    The hydrophobic interaction is significantly responsible for driving protein folding and self-assembly. To understand it, the thermodynamics, the role of water structure, the dewetting process surrounding hydrophobes, and related aspects have undergone extensive investigations. Here, we examine the hypothesis that polymer-solvent interfacial free energy is adequate to describe the energetics of the collapse of a hydrophobic homopolymer chain at fixed temperature, which serves as a much simplified model for studying the hydrophobic collapse of a protein. This implies that changes in polymer-solvent interfacial free energy should be directly proportional to the force to extend a collapsed polymer into a bad solvent. To test this hypothesis, we undertook single-molecule force spectroscopy on a collapsed, single, polystyrene chain in water-ethanol and water-salt mixtures where we measured the monomer solvation free energy from an ensemble average conformations. Different proportions within the binary mixture were used to create solvents with different interfacial free energies with polystyrene. In these mixed solvents, we observed a linear correlation between the interfacial free energy and the force required to extend the chain into solution, which is a direct measure of the solvation free energy per monomer on a single chain at room temperature. A simple analytical model compares favorably with the experimental results. This knowledge supports a common assumption that explicit water solvent may not be necessary for cases whose primary concerns are hydrophobic interactions and hydrophobic hydration.

  3. (Quasi-) 2D aggregation of polystyrene-b-dextran at the air-water interface.

    Science.gov (United States)

    Bosker, Wouter T E; Cohen Stuart, Martien A; Norde, Willem

    2013-02-26

    Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir-Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and expansion. We argue that this is due to (quasi-) 2D aggregation of the copolymer at the air-water surface, with three contributions. First, at large area per molecule, a zero surface pressure is measured; we ascribe this to self-assembly of block copolymers into surface micelles. At intermediate area we identify a second regime ("desorption regime") where aggregation into large patches occurs due to van der Waals attraction between PS blocks. At high surface pressure ("brush regime") we observe hysteretic behavior attributed to H-bonding between dextran chains. When compared to hysteresis of other amphiphilic diblock copolymers (also containing PS, e.g., polystyrene-b-poly(ethylene oxide)) a general criterion can be formulated concerning the extent of hysteresis: when the hydrophobic (PS) block is of equal size as (or bigger than) the hydrophilic block, the hysteresis is maximal. The (quasi-) 2D aggregation of PS-b-Dextran has significant implications for the preparation of dextran brushes at solid surfaces using Langmuir-Blodgett deposition. For each grafting density the monolayer needs to relax, up to several hours, prior to transfer.

  4. 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.

  5. Investigation of optical properties of aluminium oxide doped polystyrene polymer nanocomposite films

    Science.gov (United States)

    Bhavsar, Shilpa; Patel, Gnansagar B.; Singh, N. L.

    2018-03-01

    In the present work, a simple solution casting method was utilized to synthesize aluminium oxide (Al2O3) doped polystyrene (PS) polymer nanocomposite films. As synthesized films were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultra violet (UV)-visible spectroscopy, photoluminescence (PL) method and scanning electron microscopy (SEM). The crystalline nature of the films was found to decrease after incorporation of filler in the polymer matrix as revealed by XRD results. A new carbonyl group was appeared in the FTIR spectra and confirmed the charge transfer reaction between filler and polymer matrix. The decrease in the band gap was found with the filler concentration in the synthesized polymer nanocomposite films. Photoluminescence emission spectra of nanocomposites were observed at 411 nm, 435 nm and 462 nm, respectively in violet-blue region which indicates interaction between the dopant and the polymer matrix. The PL emission spectra of polymer nanocomposite films with 3 wt% of Al2O3 filler exhibited higher peak intensity. The Al2O3 filler dispersion is found to reduce band gap and promote luminescence property in polystyrene. SEM analysis indicates the agglomeration of Al2O3 nanoparticles into PS matrix at higher concentration.

  6. Jordanian silica sand and cement as a reinforcement material for polystyrene matrix composites

    International Nuclear Information System (INIS)

    Jalham, S. I.

    1999-01-01

    The behaviour of polystyrene matrix composites with different percentages of Jordaanian Silica Sand as a Reinforcement Materials (0, 5, 25, 50, and 75 wt%) and different mean grain sizes of sand particles (60, 75, 85, and 300μ m) and with cement as a boning materials in the amount fo 1/6 wt% of the wt% of silica sand were manufactured and tested under compression loading in the Industrial Engineering Department as the Uninersity of Jordan as a part of large study on local materials. The main conclusions of this investigation are: a long-term, durable structure of the polystyrene composite reinforced by silica sand and cement was achieved by mixing the constituents with water; the higher the volume fraction of the reinforcement, the higher the volume fraction of reinforcement, the higher the strength while for 75% of reinforcement, the strength dropped to an amount less than that of the matrix; the higher the grain size, the higher the strength; longitudinal brittle fracture was observed for the composites, and a homogeneous distribution of the sand particles helped in increasing the strength of the composite by playing an important role in distributing the applied load. (author). 11 refs., 6 tabs, 2 figs

  7. Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter.

    Science.gov (United States)

    Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

    2017-03-09

    Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

  8. Two-Dimensional Liquid Chromatography Analysis of Polystyrene/Polybutadiene Block Copolymers.

    Science.gov (United States)

    Lee, Sanghoon; Choi, Heejae; Chang, Taihyun; Staal, Bastiaan

    2018-05-15

    A detailed characterization of a commercial polystyrene/polybutadiene block copolymer material (Styrolux) was carried out using two-dimensional liquid chromatography (2D-LC). The Styrolux is prepared by statistical linking reaction of two different polystyrene- block-polybutadienyl anion precursors with a multivalent linking agent. Therefore, it is a mixture of a number of branched block copolymers different in molecular weight, composition, and chain architecture. While individual LC analysis, including size exclusion chromatography, interaction chromatography, or liquid chromatography at critical condition, is not good enough to resolve all the polymer species, 2D-LC separations coupling two chromatography methods were able to resolve all polymer species present in the sample; at least 13 block copolymer species and a homopolystyrene blended. Four different 2D-LC analyses combining a different pair of two LC methods provide their characteristic separation results. The separation characteristics of the 2D-LC separations are compared to elucidate the elution characteristics of the block copolymer species.

  9. 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.

  10. A bioinspired color-changing polystyrene microarray as a rapid qualitative sensor for methanol and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Wen-Kai, E-mail: wkkuo@nfu.edu.tw [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Weng, Hsueh-Ping, E-mail: sherry.weng7949@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Hsu, Jyun-Jheng, E-mail: k88520x@gmail.com [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China); Yu, Hsin Her, E-mail: hhyu@nfu.edu.tw [Department of Biotechnology, National Formosa University, 64 Wenhua Road, Huwei, Yunlin 63208, Taiwan (China)

    2016-04-15

    Polystyrene (PS) microspheres were synthesized by emulsifier-free emulsion polymerization and arranged in an array of closely packed, opal-like photonic crystals by slow self-assembly through dip-coating. This periodic array of PS microspheres was then employed as a rapid qualitative sensor for methanol and ethanol. Both solvents could be detected rapidly based on the routes of their reflection coordinates in the chromaticity diagram or directly by the naked eye on the basis of the change in color within 1 min once a solvent sample had been placed on the PS photochromic sensor. This opal-like PS sensor can thus not only be employed as a rapid sensor for methanol and ethanol but can also be used as a powerful tool for the fast screening of illicit drugs and toxic chemicals during forensic investigations. - Highlights: • Opal-like array of polystyrene (PS) microspheres is synthesized by self-assembly. • This periodic PS array is used as a rapid sensor for methanol and ethanol. • Solvents are detected by routes of reflection coordinates in chromaticity diagram. • They are also detected directly by naked eye based on change in color of sensor. • The color change is irreversible for methanol but reversible for ethanol.

  11. Colitis induced by sodium polystyrene sulfonate in sorbitol: A report of six cases.

    Science.gov (United States)

    Jacob, Sheba S K; Parameswaran, Ashok; Parameswaran, Sarojini Ashok; Dhus, Ubal

    2016-03-01

    Drug-related injury has been noted in virtually all organ systems, and recognition of the patterns of injury associated with medication enables modification of treatment and reduces the morbidity associated with the side effects of drugs. With the large number of new drugs being developed, documentation of the morphology of the changes seen as an adverse effect becomes important to characterize the pattern of injury. The pathologist is often the first to identify these abnormalities and correlate them with a particular drug. Kayexalate or sodium polystyrene sulfonate (SPS), a linear polymer derived from polystyrene containing sulfonic acid and sulfonate functional groups is used to treat hyperkalemia. It is usually administered with an osmotic laxative sorbitol orally or as retention enema. This combination has been implicated in causing damage to different parts of the gastrointestinal (GI) tract especially the colon and causes an established pattern of injury, recognizable by the presence of characteristic crystals, is presented to create a greater awareness of the Kayexalate colitis. This entity should be included in the differential diagnosis of lower GI mucosal injury in a setting of uremia and hyperkalemia.

  12. 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.

  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. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  15. Improvement in silicon-containing sulfonated polystyrene/acrylate membranes by blending and crosslinking

    International Nuclear Information System (INIS)

    Zhong Shuangling; Cui Xuejun; Dou Sen; Liu Wencong; Gao Yan; Hong Bo

    2010-01-01

    Silicon-containing sulfonated polystyrene/acrylate-poly(vinyl alcohol) (Si-sPS/A-PVA) and Si-sPS/A-PVA-phosphotungstic acid (Si-sPS/A-PVA-PWA) composite membranes were fabricated by solution blending and physical and chemical crosslinking methods to improve the properties of silicon-containing sulfonated polystyrene/acrylate (Si-sPS/A) membranes. FTIR spectra clearly show the existence of various interactions and a crosslinked silica network in composite membranes. The potential of the composites to act as proton exchange membranes in direct methanol fuel cells (DMFCs) was assessed by studying their thermal and hydrolytic stability, swelling, methanol diffusion coefficient, proton conductivity and selectivity. TGA measurements show that the composite membranes possess good thermal stability up to 190 o C, satisfying the requirement for fuel cell operation. Compared to the unmodified membrane, the composites exhibit less swelling and a superior methanol barrier. Most importantly, all of the composite membranes have significantly lower methanol diffusion coefficients and significantly higher selectivity than those of Nafion 117. The Si-sPS/A-20PVA-20PWA membrane is the best applicant for use in DMFCs because it exhibits an optimized selectivity value (5.93 x 10 5 Ss cm -3 ) that is approximately 7.8 times of that of the unmodified membrane and is 27.8 times higher than that of Nafion 117.

  16. 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)

  17. Characterization of silver/polystyrene nanocomposites prepared by in situ bulk radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vukoje, Ivana D., E-mail: ivanav@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Vodnik, Vesna V., E-mail: vodves@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Džunuzović, Jasna V., E-mail: jasnav2002@googlemail.com [Institute of Chemistry, Technology and Metallurgy (ICTM)-Center of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia); Džunuzović, Enis S., E-mail: edzunuzovic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Marinović-Cincović, Milena T., E-mail: milena@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Jeremić, Katarina, E-mail: kjeremic@tmf.bg.ac.rs [Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade (Serbia); Nedeljković, Jovan M., E-mail: jovned@vinca.rs [Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia)

    2014-01-01

    Graphical abstract: - Highlights: • Synthesis and characterization of polystyrene nanocomposites based on Ag nanoparticles. • The glass transition temperature decreased in nanocomposites with respect to the pure polymer. • Resistance of the polymer to thermal degradation enhanced with Ag nanoparticles content. - Abstract: Nanocomposites (NCs) with different content of silver nanoparticles (Ag NPs) embeded in polystyrene (PS) matrix were prepared by in situ bulk radical polymerization. The nearly monodisperse Ag NPs protected with oleylamine were synthesized via organic solvo-thermal method and further used as a filler. The as-prepared spherical Ag NPs with diameter of 7.0 ± 1.5 nm were well dispersed in the PS matrix. The structural properties of the resulting Ag/PS NCs were characterized by transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy, while optical properties were characterized using optical absorption measurements. The gel permeation chromatography (GPC) measurements showed that the presence of Ag NPs stabilized with oleylamine has no influence on the molecular weight and polydispersity of the PS matrix. The influence of silver content on the thermal properties of Ag/PS NCs was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicated that resistance of PS to thermal degradation was improved upon incorporation of Ag NPs. The Ag/PS NCs have lower glass transition temperatures than neat PS because loosely packed oleylamine molecules at the interface caused the increase of free volume and chain segments mobility near the surface of Ag NPs.

  18. Polystyrene foam products equation of state as a function of porosity and fill gas

    Energy Technology Data Exchange (ETDEWEB)

    Mulford, Roberta N [Los Alamos National Laboratory; Swift, Damian C [LLNL

    2009-01-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO{sub 2}-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O{sub 2}-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO{sub 2} decomposes at high temperatures.

  19. 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.

  20. Instantaneous x-ray radiation energy from laser produced polystyrene plasmas for shock ignition conditions

    International Nuclear Information System (INIS)

    Shang, Wanli; Wei, Huiyue; Li, Zhichao; Yi, Rongqing; Zhu, Tuo; Song, Tianmin; Huang, Chengwu; Yang, Jiamin

    2013-01-01

    Laser target energy coupling mechanism is crucial in the shock ignition (SI) scheme, and x-ray radiation energy is a non-negligible portion of the laser produced plasma energy. To evaluate the x-ray radiation energy amount at conditions relevant to SI scheme, instantaneous x-ray radiation energy is investigated experimentally with continuum phase plates smoothed lasers irradiating layer polystyrene targets. Comparative laser pulses without and with shock spike are employed. With the measured x-ray angular distribution, full space x-ray radiation energy and conversion efficiency are observed. Instantaneous scaling law of x-ray conversion efficiency is obtained as a function of laser intensity and time. It should be pointed out that the scaling law is available for any laser pulse shape and intensity, with which irradiates polystyrene planar target with intensity from 2 × 10 14 to 1.8 × 10 15 W/cm 2 . Numerical analysis of the laser energy transformation is performed, and the simulation results agree with the experimental data

  1. Polystyrene foam products equation of state as a function of porosity and fill gas

    International Nuclear Information System (INIS)

    Mulford, Roberta N.; Swift, Damian C.

    2009-01-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO 2 -blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O 2 -blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO 2 decomposes at high temperatures.

  2. 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.

  3. 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

  4. Surface modification of polystyrene with atomic oxygen radical anions-dissolved solution

    International Nuclear Information System (INIS)

    Wang Lian; Yan Lifeng; Zhao Peitao; Torimoto, Yoshifumi; Sadakata, Masayoshi; Li Quanxin

    2008-01-01

    A novel approach to surface modification of polystyrene (PS) polymer with atomic oxygen radical anions-dissolved solution (named as O - water) has been investigated. The O - water, generated by bubbling of the O - (atomic oxygen radical anion) flux into the deionized water, was characterized by UV-absorption spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. The O - water treatments caused an obvious increase of the surface hydrophilicity, surface energy, surface roughness and also caused an alteration of the surface chemical composition for PS surfaces, which were indicated by the variety of contact angle and material characterization by atomic force microscope (AFM) imaging, field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and attenuated total-reflection Fourier transform infrared (ATR-FTIR) measurements. Particularly, it was found that some hydrophilic groups such as hydroxyl (OH) and carbonyl (C=O) groups were introduced onto the polystyrene surfaces via the O - water treatment, leading to the increases of surface hydrophilicity and surface energy. The active oxygen species would react with the aromatic ring molecules on the PS surfaces and decompose the aromatic compounds to produce hydrophilic hydroxyl and carbonyl compounds. In addition, the O - water is also considered as a 'clean solution' without adding any toxic chemicals and it is easy to be handled at room temperature. Present method may suit to the surface modification of polymers and other heat-sensitive materials potentially

  5. Small-angle neutron scattering investigation of the chain conformation of lamellar polystyrene/isoprene phase in solid state

    International Nuclear Information System (INIS)

    Constantinescu, L.M.

    1994-01-01

    Small-angle neutron scattering has been used in the study of chain conformation of lamellar styrene/isoprene block copolymers oriented in large single crystals. The radius of gyration of deuterated polystyrene chains around the normal to the interface has been measured. By comparing this direct evolution of the lateral dimension of the chains with the average chain separation given by the molecular area (the surface available at the interface for each covalent bond linking the blocks together) we characterized the transverse interpenetration degree of the chains. The polystyrene chains are displayed in simple strata own micro-domains, without an important interpenetration. (Author) 9 Figs., 2 Tabs., 25 Refs

  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. Destruction behavior of hexabromocyclododecanes during incineration of solid waste containing expanded and extruded polystyrene insulation foams.

    Science.gov (United States)

    Takigami, Hidetaka; Watanabe, Mafumi; Kajiwara, Natsuko

    2014-12-01

    Hexabromocyclododecanes (HBCDs) have been used for flame retardation mainly in expanded polystyrene (EPS) and extruded polystyrene (XPS) insulation foams. Controlled incineration experiments with solid wastes containing each of EPS and XPS were conducted using a pilot-scale incinerator to investigate the destruction behavior of HBCDs and their influence on the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs). EPS and XPS materials were respectively blended with refuse derived fuel (RDF) as input wastes for incineration. Concentrations of HBCDs contained in the EPS- and XPS-added RDFs, were 140 and 1100 mg kg(-1), respectively. In which γ-HBCD was dominant (68% of the total HBCD content) in EPS-added RDF and α-HBCD accounted for 73% of the total HBCDs in XPS-added RDF. During the incineration experiments with EPS and XPS, primary and secondary combustion zones were maintained at temperatures of 840 °C and 900 °C. The residence times of waste in the primary combustion zone and flue gas in the secondary combustion zone was 30 min and three seconds, respectively. HBCDs were steadily degraded in the combustion chambers and α-, β-, and γ-HBCD behaved similarly. Concentration levels of the total HBCDs in the bag filter exit gas for the two experiments with EPS and XPS were 0.7 and 0.6ngmN(-3), respectively. HBCDs were also not detected (incineration process with destruction efficiencies of more than 99.9999 for both of EPS and XPS cases. For PBDD/DFs, the levels detected in the bottom and fly ash samples were very low (0.028 ng g(-1) at maximum). In the case of XPS-added experiment, 2,3,7,8-TeBDD and 2,3,7,8-TeBDF were determined in the flue gas at levels (0.05-0.07 ng mN(-3)) slightly over the detection limits in the environmental emission gas samples, suggesting HBCDs in XPS are possibly a precursor of detected PBDD/DFs. Operational care should be taken when the ratio of HBCD-containing polystyrene is increased in the input wastes just

  8. Manufacturing and Morphological Analysis of Composite Material of Polystyrene Nanospheres/Cadmium Metal Nanoparticles

    Directory of Open Access Journals (Sweden)

    Pratama Jujur Wibawa

    2013-03-01

    Full Text Available A very simple nanocomposite material has been in-situ manufactured from an aqueous polystyrene nanospheres dispersion and cadmium (Cd metal nanoparticles. The manufacturing was performed by using a high frequency of 40 kHz ultrasonic (US agitation for 45 minute at atmospheric pressure and at room temperature 20 oC. No chemical reducing agent and surfactant added in this manufacturing technique due to the US could reduce Cd2+ ions of cadmium nitrate tetrahydrate to Cd atomic metals nanoparticles whereas water molecules could act as a pseudo stabilizer for the manufactured material. A thin film was manufactured from aqueous colloidal nanocomposite material of Polystyrene nanospheres/Cd metal nanoparticles (PSNs/CdMNp fabricated on a hydrophilic silicon wafer. The thin film was then characterized by a JEOL-FESEM for its surface morphology characteristic and by ATR-FTIR spectrometry for its molecular change investigation. It could be clearly observed that surface morphology of the thin film material was not significantly changed under 633 nm wavelength continuous laser radiation exposure for 20 minute. In addition, its ATR-FTIR spectra of wave number peaks around 3400 cm-1 have been totally disappeared under the laser exposure whereas that at around 699 cm-1 and 668 cm-1 have not been significantly changed. The first phenomenon indicated that the hydrogen bond existed in PSNs/CdMNp material was collapsed by the laser exposure. The second phenomena indicated that the PSNs phenyl ring moiety was not totally destroyed under the laser exposure. It was suspected due to the existence of Cd nanoparticles covered throughout the spherical surface of PSNs/CdMNp material particles. Therefore a nice model of material structure of the mentioned PSNs/CdMNp nanocomposite material could be suggested in this research. It could be concluded that this research have been performed since the material structure model of the manufactured PSNs/CdMNp nanocomposite could be

  9. Reactive Imprint Lithography: Combined Topographical Patterning and Chemical Surface Functionalization of Polystyrene-block-poly(tert-butyl acrylate) Films

    NARCIS (Netherlands)

    Duvigneau, Joost; Cornelissen, Stijn; Bardajı´Valls, Nuria; Schönherr, Holger; Vancso, Gyula J.

    2009-01-01

    Here, reactive imprint lithography (RIL) is introduced as a new, one-step lithographic tool for the fabrication of large-area topographically patterned, chemically activated polymer platforms. Films of polystyrene-block-poly(tert-butyl acrylate) (PS-b-PtBA) are imprinted with PDMS master stamps at

  10. Kinetics of the low-temperature pyrolysis of polyethene, polypropene and polystyrene modeling, experimental determination and comparison with literature data.

    NARCIS (Netherlands)

    Westerhout, R.W.J.; Westerhout, R.W.J.; Waanders, J.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1997-01-01

    The pyrolysis kinetics of low-density polyethylene, high-density polyethylene, polypropylene, and polystyrene has been studied at temperatures below 450 C. In addition, a literature review on the low-temperature pyrolysis of these polymers has been conducted and has revealed that the scatter in the

  11. Fast synthesis, formation mechanism, and control of shell thickness of CuS–polystyrene core–shell microspheres

    International Nuclear Information System (INIS)

    Zhao, Li-min; Shao, Xin; Yin, Yi-bin; Li, Wen-zhi

    2012-01-01

    Graphical abstract: Core–shell structure PSt/CuS were prepared using polystyrene which were modified by 3-methacryloxypropyltrimethoxysilane as template. The coating thickness of CuS can be controlled by the amount of 3-methacryloxypropyltrimethoxysilane and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. Highlights: ► Core–shell structure PSt/CuS were prepared using silanol-modified polystyrene microspheres as template. ► The coating thickness of core–shell structure PSt/CuS can be controlled by a simple method. ► The UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. -- Abstract: The silanol-modified polystyrene microspheres were prepared through dispersion polymerization. Then copper sulfide particles were grown on silanol-modified polystyrene through sonochemical deposition in an aqueous bath containing copper acetate and sulfide, released through the hydrolysis of thioacetamide. The resulting particles were continuous and uniform as characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared, thermogravimetric analysis and UV–vis absorption spectroscopy were used to characterize the structure and properties of core–shell particles. The results showed the coating thickness of CuS shell can be controlled by the amount of silanol and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS.

  12. 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...

  13. The Incredible Shrinking Cup Lab: An Investigation of the Effect of Depth and Water Pressure on Polystyrene

    Science.gov (United States)

    This activity familiarizes students with the effects of increased depth on pressure and volume. Students will determine the volume of polystyrene cups before and after they are submerged to differing depths in the ocean and the Laurentian Great Lakes. Students will also calculate...

  14. Pore Structure and Fluoride Ion Adsorption Characteristics of Zr (IV) Surface-Immobilized Resin Prepared Using Polystyrene as a Porogen

    Science.gov (United States)

    Mizuki, Hidenobu; Ito, Yudai; Harada, Hisashi; Uezu, Kazuya

    Zr(IV) surface-immobilized resins for removal of fluoride ion were prepared by surface template polymerization using polystyrene as a porogen. At polymerization, polystyrene was added in order to increase mesopores (2-50 nm) and macropore (>50 nm) with large macropores (around 300 nm) formed with internal aqueous phase of W⁄O emulsion. The pore structure of Zr(IV) surface-immobilized resins was evaluated by measuring specific surface area, pore volume, and pore size distribution with volumetric adsorption measurement instrument and mercury porosimeter. The adsorption isotherms were well fitted by Langmuir equation. The removal of fluoride was also carried out with column method. Zr(IV) surface-immobilized resins, using 10 g⁄L polystyrene in toluene at polymerization, possessed higher volume of not only mesopores and macropores but also large macropores. Furethermore, by adding the polystyrene with smaller molecular size, the pore volume of mesopores, macropores and large macropores was significantly increased, and the fluoride ion adsorption capacity and the column utilization also increased.

  15. Dynamics of polyelectrolyte adsorption and colloidal flocculation upon mixing studied using mono-dispersed polystyrene latex particles

    NARCIS (Netherlands)

    Feng, Lili; Cohen Stuart, Martien; Adachi, Yasuhisa

    2015-01-01

    The dynamic behavior of polyelectrolytes just after their encounter with the surface of bare colloidal particles is analyzed, using the flocculation properties of mono-dispersed polystyrene latex (PSL) particles. Applying a Standardized Colloid Mixing (SCM) approach, effects of ionic strength and

  16. Elongational viscosity of narrow molar mass distribution polystyrene. Anders Bach, Kristoffer Almdal, Henrik Koblitz Rasmussen and Ole Hassager

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...

  17. Air bubble-induced detachment of polystyrene particles with different sizes from collector surfaces in a parallel plate flow chamber

    NARCIS (Netherlands)

    Gomez-Suarez, C; van der Mei, HC; Busscher, HJ

    2001-01-01

    Particle size was found to be an important factor in air bubble-induced detachment of colloidal particles from collector surfaces in a parallel plate flow chamber and generally polystyrene particles with a diameter of 806 nm detached less than particles with a diameter of 1400 nm. Particle

  18. Probing the surface swelling in ultra-thin supported polystyrene films during case II diffusion of n-hexane

    NARCIS (Netherlands)

    Ogieglo, Wojciech; Wormeester, Herbert; Wessling, Matthias; Benes, Nieck Edwin

    2013-01-01

    In situ time-resolved spectroscopic ellipsometry is used to study the dynamics of n-hexane diffusion into, and the corresponding induced swelling of, ultra-thin polystyrene films. The experimental conditions are carefully selected to facilitate the observation of anomalous Case II diffusion in the

  19. Stabilization of colloidal palladium particles by a block copolymer of polystyrene and a block containing amide sidegroups

    NARCIS (Netherlands)

    Roescher, G.A.; Roescher, A.; Hempenius, Mark A.; Klok, H.A.; Moller, M.; Möller, M.

    1996-01-01

    A block copolymer of polystyrene and poly(tert-butylmethacrylate) was prepared by anionic polymerization. The ester groups of the poly(tert-butylmethacrylate) were hydrolyzed, after wich the remaining carboxyl groups were reacted with pyrrolidine. The resulting block copolymer with amide sidegroups

  20. 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 OBOR OECD: Chemical process engineering Impact factor: 2.991, year: 2016

  1. Investigation the effect of time detention on the removal of chromuim from aqueous solution by using polyaniline/polystyrene nanocomposite

    International Nuclear Information System (INIS)

    Eisazade, Hossein; Davodi, Behzad; Soleimani lashkenari, Mohammad

    2010-01-01

    In this study Polyaniline/polystyrene nanocomposites were prepared in the aqueous solution by using ammonium peroxy disulfate as an oxidant in the presence of poly (vinyl pyrrolidone) as surfactant. Morphology and chemical structure was characterized by using scaning electron micrograph(SEM), fourier transform infrared (FTIR) spectrometer and removal percentage obtained by using mass atomic absorption.

  2. 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......The flocculation of colloidal suspensions is an important unit operation in many industries, as it greatly improves the performance of solid separation processes. The number of available techniques for evaluating flocculation processes on line is limited, and most of these are only functional...... 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....

  3. Preparation and characterization of ω-functionalized polystyrene-magnetite nanocomposites

    International Nuclear Information System (INIS)

    Jiang Liming; Sun Weilin; Kim, Jungahn

    2007-01-01

    Magnetite (Fe 3 O 4 ) nanoparticles were prepared by in situ precipitation and oxidation of ferrous ions in the presence of ω-functionalized polystyrenes having carboxylate, sulfonate, thiol, and thiolated groups. Based on the results for the orthogonal experimental design, both the ratio of the concentration of iron precursor to polymer and the reaction temperature were the major factors controlling the particle size and its shape morphology. By adjusting the reaction conditions, the iron oxide particle size can be effectively controlled in the range between 2 and 20 nm. The magnetite-based polymer composite was characterized by UV-vis spectroscopy, thermogravimetric analysis, transmission electron microscopy, and X-ray diffraction. Magnetization measurements revealed that the nanocomposite materials exhibit superparamagnetic behavior at room temperature

  4. Preparation and characterization of {omega}-functionalized polystyrene-magnetite nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Liming [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China)]. E-mail: cejlm@zju.edu.cn; Sun Weilin [Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Kim, Jungahn [Polymer Hybrids Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

    2007-02-15

    Magnetite (Fe{sub 3}O{sub 4}) nanoparticles were prepared by in situ precipitation and oxidation of ferrous ions in the presence of {omega}-functionalized polystyrenes having carboxylate, sulfonate, thiol, and thiolated groups. Based on the results for the orthogonal experimental design, both the ratio of the concentration of iron precursor to polymer and the reaction temperature were the major factors controlling the particle size and its shape morphology. By adjusting the reaction conditions, the iron oxide particle size can be effectively controlled in the range between 2 and 20 nm. The magnetite-based polymer composite was characterized by UV-vis spectroscopy, thermogravimetric analysis, transmission electron microscopy, and X-ray diffraction. Magnetization measurements revealed that the nanocomposite materials exhibit superparamagnetic behavior at room temperature.

  5. Biocidal action of ozone-treated polystyrene surfaces on vegetative and sporulated bacteria

    International Nuclear Information System (INIS)

    Mahfoudh, Ahlem; Barbeau, Jean; Moisan, Michel; Leduc, Annie; Seguin, Jacynthe

    2010-01-01

    Surfaces of materials can be modified to ensure specific interaction features with microorganisms. The current work discloses biocidal properties of polystyrene (PS) Petri-dish surfaces that have been exposed to a dry gaseous-ozone flow. Such treated PS surfaces are able to inactivate various species of vegetative and sporulated bacteria on a relatively short contact time. Denaturation of proteins seems likely based on a significant loss of enzymatic activity of the lysozyme protein. Characterization of these surfaces by atomic-force microscopy (AFM), Fourier-transform infra-red (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) reveals specific structural and chemical modifications as compared to untreated PS. Persistence of the biocidal properties of these treated surfaces is observed. This ozone-induced process is technically simple to achieve and does not require active precursors as in grafting.

  6. Encapsulation of magnetic nanoparticles with polystyrene via emulsifier-free miniemulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Faridi-Majidi, R. [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of)]. E-mail: refaridi@khayam.ut.ac.ir; Sharifi-Sanjani, N. [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of); Agend, F. [Malek-Ashtar University, Lavizan, Tehran (Iran, Islamic Republic of)

    2006-09-25

    Magnetite nanoparticles (Fe{sub 3}O{sub 4}), with an average size of about 10 nm, were encapsulated with polystyrene using a new method based on emulsifier-free miniemulsion polymerization in the presence of 2, 2' azobis (2-amidinopropane) dihydrochloride (V-50) as a cationic ionizable water-soluble initiator and hexadecane as a hydrophobe. Transmission electron microscopy (TEM) proved the presence of magnetite in polymer particles which appeared to be monodisperse in size, approximately 100-300 nm in diameter, through TEM and scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) measurement was used to determine the percentage of magnetite in the products. The results of emulsifier-free miniemulsion polymerization were compared with those of conventional emulsifier-free emulsion polymerization using (V-50) as the initiator in both cases.

  7. Encapsulation of magnetic nanoparticles with polystyrene via emulsifier-free miniemulsion polymerization

    International Nuclear Information System (INIS)

    Faridi-Majidi, R.; Sharifi-Sanjani, N.; Agend, F.

    2006-01-01

    Magnetite nanoparticles (Fe 3 O 4 ), with an average size of about 10 nm, were encapsulated with polystyrene using a new method based on emulsifier-free miniemulsion polymerization in the presence of 2, 2' azobis (2-amidinopropane) dihydrochloride (V-50) as a cationic ionizable water-soluble initiator and hexadecane as a hydrophobe. Transmission electron microscopy (TEM) proved the presence of magnetite in polymer particles which appeared to be monodisperse in size, approximately 100-300 nm in diameter, through TEM and scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) measurement was used to determine the percentage of magnetite in the products. The results of emulsifier-free miniemulsion polymerization were compared with those of conventional emulsifier-free emulsion polymerization using (V-50) as the initiator in both cases

  8. Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

    Science.gov (United States)

    McCarthy, K. J.; Tamura, N.; Combs, S. K.; Panadero, N.; Ascabíbar, E.; Estrada, T.; García, R.; Hernández Sánchez, J.; López Fraguas, A.; Navarro, M.; Pastor, I.; Soleto, A.; TJ-II Team

    2017-10-01

    A cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun-type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection compared with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.

  9. High impact polystyrene (HIPS). Predicting its molecular, morphological and mechanical properties

    International Nuclear Information System (INIS)

    Luciani, C; Estenoz, D; Morales, G; Meira, G

    2004-01-01

    A mathematical model that is able to predict the molecular and morphological structure of high impact polystyrene (HIPS) and the Fluidity Index (MFI) is presented. The model is divided into two parts: a) the estimation of the material's molecular and morphological properties, simulating the polymerization process in discontinuous mass based on the recipe and the conditions of synthesis; and b) the prediction of rheological variables (viscosity at low deformation speeds and relaxation time), and of the MFI, based on average molecular and morphological variables. The model also combines with empirical correlations proposed in the literature [1] in order to estimate impact strength (IS). The predictions for a), b) and impact strength were co-validated by independent data and resulted in a good fit (CW)

  10. 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.

  11. Polystyrene-Supported Acyclic Diaminocarbene Palladium Complexes in Sonogashira Cross-Coupling: Stability vs. Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Vladimir N. Mikhaylov

    2018-04-01

    Full Text Available Two types of immobilized on the amino-functionalized polystyrene-supported acyclic diaminocarbene palladium complexes (ADC-PdII are investigated under Sonogashira cross-coupling conditions. Depending on substituents in the diaminocarbene fragment immobilized ADC-PdII, systems are found to have different catalytic activity and stability regarding Pd-leaching. PdII-diaminocarbenes possessing protons at both nitrogen atoms smoothly decompose into Pd0-containing species providing a catalytic “cocktail system” with high activity and ability to reuse within nine runs. Polymer-supported palladium (II complex bearing NBn–Ccarbene–NH-moiety exhibits greater stability while noticeably lower activity under Sonogashira cross-coupling. Four molecular ADC-PdII complexes are also synthesized and investigated with the aim of confirming proposed base-promoted pathway of ADC-PdII conversion through carbodiimide into an active Pd0 forms.

  12. Mercuric iodide composite films using polyamide, polycarbonate and polystyrene fabricated by casting

    International Nuclear Information System (INIS)

    Ugucioni, J.C.; Ghilardi Netto, T.; Mulato, M.

    2010-01-01

    Mercuric iodide (HgI 2 ) composite films were obtained by using the casting technique. Insulator polymers such as polyamide, polycarbonate and polystyrene were mixed to HgI 2 crystallites forming a final sub-millimeter thick self-standing film. Fabrication temperature varied from 10 to 100 o C, and total fabrication time reached at most 5 min. The larger the fabrication temperature, the thinner the film and the smaller its electrical resistivity. Electrical characterization was performed in the dark, under UV illumination and under mammographic X-ray exposure. The final properties of the films are discussed and related to fabrication conditions. The optimized composite film might be a better candidate for use as X-ray detector for medical imaging, in place of the single HgI 2 crystalline device.

  13. Mean excitation energy of polystyrene extracted from proton-stopping-power measurements

    International Nuclear Information System (INIS)

    Porter, L.E.

    1980-01-01

    The measured stopping power of polystyrene for 2.2- to 5.9-MeV protons has been analyzed with the Bloch projectile-z 4 correction term and a modified low-velocity projectile-z 3 term included in the Bethe-Bloch formula. When the full-strength Walske K-shell correction was utilized, the mean excitation energy corresponding to the best fit of the measurements was (71.1 +- 1.8) eV. This result was obtained for a value of the free parameter of the low-velocity projectile-z 3 effect formalism of 1.90 +- 0.05, whether or not a Walske L-shell correction was included

  14. Polystyrene sphere monolayer assisted electrochemical deposition of ZnO nanorods with controlable surface density

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, D., E-mail: daniel.ramirez@ucv.c [Laboratorio de Electroquimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Gomez, H. [Laboratorio de Electroquimica, Pontificia Universidad Catolica de Valparaiso, Valparaiso (Chile); Lincot, D. [Institute de Recherche et Developpement sur l' Energie Photovoltaique-IRDEP, 6 Quai Watier 78401, Chatou Cedex (France)

    2010-02-15

    In this paper we report the zinc oxide nanorods (ZnO NRs) growth by electrochemical deposition onto polycrystalline gold electrodes modified with assemblies of polystyrene sphere monolayers (PSSMs). Growth occurs through the interstitial spaces between the hexagonally close packed spheres. ZnO NRs nucleate in the region where three adjacent spheres leave a space, being able to grow and projected over the PSSMs. The nanorod surface density (N{sub NR}) shows a linear dependence with respect to a PS sphere diameter selected. XRD analysis shows these ZnO NRs are highly oriented along the (0 0 2) plane (c-axis). This open the possibility to have electronic devices with mechanically supported nanometric materials.

  15. A novel approach for preparation of micrometer-sized, monodisperse dimple and hemispherical polystyrene particles.

    Science.gov (United States)

    Tanaka, Takuya; Komatsu, Yoshifumi; Fujibayashi, Teruhisa; Minami, Hideto; Okubo, Masayoshi

    2010-03-16

    Micrometer-sized, monodisperse dimple and hemispherical polystyrene (PS) particles were successfully prepared by heating (55-70 degrees C) of spherical PS particles dispersed in methanol/water media (40/60 to 80/20, w/w) in the presence of decane droplets, and subsequent cooling down to room temperature. Decane was absorbed by the PS particles during the heating process. Decane-absorbed PS particles phase-separated into PS and decane phases in the inside during the cooling process, and eventually dimple and/or hemispherical particles were formed by removal of the decane phase from phase-separated PS/decane particles by evaporation. The size of the dimple, which is determined by the volume of decane phase-separated from decane-absorbed PS particles during the cooling process, increased with increases in the heating temperature and the methanol content.

  16. Worst case prediction of additives migration from polystyrene for food safety purposes: a model update.

    Science.gov (United States)

    Martínez-López, Brais; Gontard, Nathalie; Peyron, Stéphane

    2018-03-01

    A reliable prediction of migration levels of plastic additives into food requires a robust estimation of diffusivity. Predictive modelling of diffusivity as recommended by the EU commission is carried out using a semi-empirical equation that relies on two polymer-dependent parameters. These parameters were determined for the polymers most used by packaging industry (LLDPE, HDPE, PP, PET, PS, HIPS) from the diffusivity data available at that time. In the specific case of general purpose polystyrene, the diffusivity data published since then shows that the use of the equation with the original parameters results in systematic underestimation of diffusivity. The goal of this study was therefore, to propose an update of the aforementioned parameters for PS on the basis of up to date diffusivity data, so the equation can be used for a reasoned overestimation of diffusivity.

  17. Self-Assembled Polystyrene Beads for Templated Covalent Functionalization of Graphitic Substrates Using Diazonium Chemistry.

    Science.gov (United States)

    Van Gorp, Hans; Walke, Peter; Bragança, Ana M; Greenwood, John; Ivasenko, Oleksandr; Hirsch, Brandon E; De Feyter, Steven

    2018-04-11

    A network of self-assembled polystyrene beads was employed as a lithographic mask during covalent functionalization reactions on graphitic surfaces to create nanocorrals for confined molecular self-assembly studies. The beads were initially assembled into hexagonal arrays at the air-liquid interface and then transferred to the substrate surface. Subsequent electrochemical grafting reactions involving aryl diazonium molecules created covalently bound molecular units that were localized in the void space between the nanospheres. Removal of the bead template exposed hexagonally arranged circular nanocorrals separated by regions of chemisorbed molecules. Small molecule self-assembly was then investigated inside the resultant nanocorrals using scanning tunneling microscopy to highlight localized confinement effects. Overall, this work illustrates the utility of self-assembly principles to transcend length scale gaps in the development of hierarchically patterned molecular materials.

  18. Ion-beam-induced aggregation in polystyrene: The influence of the molecular parameters

    International Nuclear Information System (INIS)

    Puglisi, O.; Licciardello, A.; Calcagno, L.; Foti, G.

    1988-01-01

    The formation of an insoluble gel under ion-beam bombardment is governed by ion-beam parameters and target parameters. Here reported is a study of the influence of the target molecular parameters on the sol--gel transition of ion-bombarded polystyrene with particular emphasis for the number-average molecular weight M-bar/sub n/. It is shown that the main parameter is the number of macromolcules of the film so that by adopting a ''corrected'' fluence F/n (ions per macromolecule), the different curves of the various polymers collapse in only one universal curve. The importance of the ''corrected'' fluence is shown also at molecular level and the MWD of the various polymers is similar at equal F/n values. An experimental model is outlined which explains the sol--gel transition on the basis of transition from an isolated-track regime to an overlap regime where the formation of insoluble giant macromolecules occurs

  19. Novel dense CO2 technique for beta-galactosidase immobilization in polystyrene microchannels.

    Science.gov (United States)

    Leclair Ellis, Jeffrey; Tomasko, David L; Dehghani, Fariba

    2008-03-01

    In this study we design new fabrication techniques and demonstrate the potential of using dense CO2 for facilitating crucial steps in the fabrication of polymeric lab-on-a-chip microdevices by embedding biomolecules at temperatures well below the polymer's glass transition temperature (T(g)). These new techniques are environmentally friendly and done without the use of a clean room. Carbon dioxide at 40 degrees C and between 4.48 and 6.89 MPa was used to immobilize the biologically active molecule, beta-galactosidase (beta-gal), on the surface of polystyrene microchannels. To our knowledge, this is the first time dense CO2 has been used to directly immobilize an enzyme in a microchannel. beta-gal activity was maintained and shown via a fluorescent reaction product, after enzyme immobilization and microchannel capping by the designed fabrication steps at 40 degrees C and pressures up to 6.89 MPa.

  20. Synthesis of Dibenzo[hi,st]ovalene and Its Amplified Spontaneous Emission in a Polystyrene Matrix.

    Science.gov (United States)

    Paternò, Giuseppe M; Chen, Qiang; Wang, Xiao-Ye; Liu, Junzhi; Motti, Silvia G; Petrozza, Annamaria; Feng, Xinliang; Lanzani, Guglielmo; Müllen, Klaus; Narita, Akimitsu; Scotognella, Francesco

    2017-06-06

    A large number of graphene molecules, or large polycyclic aromatic hydrocarbons (PAHs), have been synthesized and display various optoelectronic properties. Nevertheless, their potential for application in photonics has remained largely unexplored. Herein, we describe the synthesis of a highly luminescent and stable graphene molecule, namely a substituted dibenzo[hi,st]ovalene (DBO 1), with zigzag edges and elucidate its promising optical-gain properties by means of ultrafast transient absorption spectroscopy. Upon incorporation of DBO into an inert polystyrene matrix, amplified stimulated emission can be observed with a relatively low power threshold (ca. 60 μJ cm -2 ), thus highlighting its high potential for lasing applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Mechanism of wavelength conversion in polystyrene doped with benzoxanthene: emergence of a complex.

    Science.gov (United States)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Kitamura, Hisashi; Sato, Nobuhiro; Shinji, Osamu; Saito, Katashi; Takahashi, Sentaro

    2013-01-01

    Fluorescent guest molecules doped in polymers have been used to convert ultraviolet light into visible light for applications ranging from optical fibres to filters for the cultivation of plants. The wavelength conversion process involves the absorption of light at short wavelengths followed by fluorescence emission at a longer wavelength. However, a precise understanding of the light conversion remains unclear. Here we show light responses for a purified polystyrene base substrates doped with fluorescent benzoxanthene in concentrations varied over four orders of magnitude. The shape of the excitation spectrum for fluorescence emission changes significantly with the concentration of the benzoxanthene, indicating formation of a base substrate/fluorescent molecule complex. Furthermore, the wavelength conversion light yield increases in three stages depending on the nature of the complex. These findings identify a mechanism that will have many applications in wavelength conversion materials.

  2. Molecular differences between deuterated and protonated polystyrenes using reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Kayillo, Sindy; Gray, Michael J; Shalliker, R Andrew; Dennis, Gary R

    2005-05-06

    Isotopic substitution is a technique used to highlight particular bonds within a molecule for kinetic, spectroscopic and structure analysis. It is presumed that although some properties such as stretching frequencies will not be the same for substituted analogues, the chemical interactions will not vary appreciably as a function of labelling. Reversed-phase liquid chromatography has been used to demonstrate that there are significant differences between the chromatographic behaviour of a sequence of deuterated and protonated oligomeric polystyrenes. Two-dimensional reversed-phase liquid chromatography was used to show that even the diasteromers of the oligomers (n = 5) have retention mechanisms that are dependent on the subtle changes to the molecular conformation and electronic structure, which are a consequence of deuteration.

  3. Detection of creatinine enriched on a surface imprinted polystyrene film using FT-ATR-IR.

    Science.gov (United States)

    Sreenivasan, K

    2006-01-01

    The surface of polystyrene (PS) was chemically modified by coating a thin layer of polyaniline (PANI) by oxidizing aniline using ammonium persulfate. Affinity sites for creatinine, a clinically relevant molecule, were created in the coated layer by adding creatinine as print molecules during the oxidation. The imprinted layer adsorbed creatinine was compared to non-imprinted surface reflecting the creation of creatinine-specific sites on the surface. The equilibrium was attained rapidly, indicating that a material of this kind is suitable for sensing applications. The adsorbed creatinine on the surface was detected using the technique of Fourier transform attenuated total internal reflection infra red spectroscopy (FT-ATR-IR). The results show that molecularly imprinted surface can enrich molecules of interest and the enriched molecules can be detected using FT-IR.

  4. Polystyrene Backbone Polymers Consisting of Alkyl-Substituted Triazine Side Groups for Phosphorescent OLEDs

    Directory of Open Access Journals (Sweden)

    Beatrice Ch. D. Salert

    2012-01-01

    Full Text Available This paper describes the synthesis of new electron-transporting styrene monomers and their corresponding polystyrenes all with a 2,4,6-triphenyl-1,3,5-triazine basic structure in the side group. The monomers differ in the alkyl substitution and in the meta-/paralinkage of the triazine to the polymer backbone. The thermal and spectroscopic properties of the new electron-transporting polymers are discussed in regard to their chemical structures. Phosphorescent OLEDs were prepared using the obtained electron-transporting polymers as the emissive layer material in blend systems together with a green iridium-based emitter 13 and a small molecule as an additional cohost with wideband gap characteristics (CoH-001. The performance of the OLEDs was characterized and discussed in regard to the chemical structure of the new electron-transporting polymers.

  5. 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.

  6. 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.

  7. Production and testing of 244Cm-labeled fluorescent polystyrene latex microspheres

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Mueller, H.L.; Brodbeck, R.D.

    1988-01-01

    To provide a useful tool for studying the mechanisms of retention and translocation of respirable-sized, alpha-emitting particles, we have developed a method of incorporating 244 Cm into fluorescent polystyrene latex microspheres. The resultant particles contain alpha radioactivity comparable to μm-size (AMAD) 239 Pu0 2 particles, but are easily visible by fluorescent light microscopy. Preliminary testing of the particles with dog macrophages in vitro has shown that the initial uptake of these Cm-labeled particles is more rapid than uptake of unlabeled particles of similar size. We are continuing to develop procedures for achieving better particle yields, smaller dispersity of particle size distributions and improved retention of the Cm label by the particles. (author)

  8. Production and testing of {sup 244}Cm-labeled fluorescent polystyrene latex microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R A; Mueller, H L; Brodbeck, R D

    1988-12-01

    To provide a useful tool for studying the mechanisms of retention and translocation of respirable-sized, alpha-emitting particles, we have developed a method of incorporating {sup 244}Cm into fluorescent polystyrene latex microspheres. The resultant particles contain alpha radioactivity comparable to {mu}m-size (AMAD) {sup 239}Pu0{sub 2} particles, but are easily visible by fluorescent light microscopy. Preliminary testing of the particles with dog macrophages in vitro has shown that the initial uptake of these Cm-labeled particles is more rapid than uptake of unlabeled particles of similar size. We are continuing to develop procedures for achieving better particle yields, smaller dispersity of particle size distributions and improved retention of the Cm label by the particles. (author)

  9. Wettability transition of plasma-treated polystyrene micro/nano pillars-aligned patterns

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available This paper reports the wettability transition of plasma-treated polystyrene (PS micro/nano pillars-aligned patterns. The micro/nano pillars were prepared using hot embossing on silicon microporous template and alumina nanoporous template, which were fabricated by ultraviolet (UV lithography and inductive coupled plasma (ICP etching, and two-step anodic oxidation, respectively. The results indicate that the combination of micro/nano patterning and plasma irradiation can easily regulate wettabilities of PS surfaces, i.e. from hydrophilicity to hydrophobicity, or from hydrophobicity to superhydrophilicity. During the wettability transition from hydrophobicity to hydrophilicity there is only mild hydrophilicity loss. After plasma irradiation, moreover, the wettability of PS micro/nano pillars-aligned patterns is more stable than that of flat PS surfaces. The observed wettability transition and wettability stability of PS micro/nano pillars-aligned patterns are new phenomena, which may have potential in creating programmable functional polymer surfaces.

  10. Investigation of transitions and relaxation processes in polystyrene by using positron annihilation

    International Nuclear Information System (INIS)

    Ban, M.; Kyoto, M.

    1996-01-01

    The glass transition and relaxation processes in polystyrene resins with the number average molecular weight ranging from 7.0 x 10 2 to 9.8 x 10 4 were studied with the positron annihilation technique. The pick-off annihilation lifetime of ortho-positronium (τ 3 ) and its intensity (Ι 3 ) were measured in the temperature range from 20 to 430 K. The glass transition temperature (Τ g ) was determined as an onset temperature coefficient of τ 3 x Τ g shows the molecular weight dependence in these samples. Below Τ g , local motions were detected by measurements of Ι 3 . The local motions could be observed above 100 K in this experiment. Ι 3 show the minimum at around 250 K and it does not show molecular weight dependence. (author)

  11. Improvement of radiation resistance of polypropylene by blending with polyethylene and polystyrene

    International Nuclear Information System (INIS)

    Al Aji, Z.

    2001-01-01

    The use of polypropylene in production of medical component and packaging materials makes it an interesting material for applied research. Since the use of ethylene oxide for sterilization of medical components will be forbidden in the next future because of its carcinogens effect. Therefore, another alternative sterilization methods are required. The use of Gamma radiation is already established for sterilization of some medical components, this technique causes change in the physical mechanical properties of polypropylene, which makes the addition of stabilizers necessary. In this work, blends of domestically used polymers, polypropylene, linear low-density polyethylene, and polystyrene/butadiene were prepared in order to improve the radiation resistance of polypropylene; naphthalene was also used as an additive

  12. Irradiation of Polystyrene and Polypropylene to study NIH 3T3 fibroblasts adhesion

    International Nuclear Information System (INIS)

    Arbeitman, C.R.; Grosso, M.F. del; Ibanez, I.; Garcia Bermudez, G.; Duran, H.; Chappa, V.C.; Mazzei, R.; Behar, M.

    2010-01-01

    When polymers are irradiated with heavy ions new chemical groups are created in a few microns of the material. The irradiation changed the polarity and wettability on the surface so that could enhance the biocompatibility of the modified polymer. The study of chemistry and nanoscale topography of the biomaterial is important in determining its potential applications in medicine and biotechnology, because their strong influence on cell function, adhesion and proliferation. In this study, thin films of Polystyrene and Polypropylene samples were modified by irradiation with low energy ion beams (30-150 keV) and swift heavy ions both with various fluences and energies. The changes were evaluated with different methods. Adhesion of NIH 3T3 fibroblasts onto unirradiated and irradiated surfaces has been studied by in vitro techniques. The correlations between physicochemical properties as a function of different irradiations parameters were compared with cell adhesion on the modified polymer surface.

  13. 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...... that the entanglement density M/Me of the solution coincided with that of PS 290k melt (M = 290k). After the elongation at the Rouse-based Weissenberg number Wi(R) ~ 3 up to the Hencky strain of 3, the short time stress relaxation of the solution was accelerated by a factor of ~4, which was less significant compared...... and the lack of monotonic thinning observed for the semidilute solutions. Results for less concentrated solutions will be also presented on site....

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

    DEFF Research Database (Denmark)

    Hinge, Mogens

    Separating a solid from a liquid is an important unit operation in many different industries e.g. mining, chemical, pharmaceutical and food industries. Solid liquid separation can roughly be divided into three groups. 1) Separation by gravity forces e.g. sedimentation, centrifugation, 2) Separation...... consisting of a solid poly(styrene) (PS) core with a water swollen shell have been employed in investigating the effect from varying amounts and type of water swollen material on filtration dewatering properties. Three series of model material have been used in this investigation 1) poly......(styrene-co-acrylic acid) core-shell colloids with varying thickness of the poly(acrylic acid) (PAA) shell. 2) poly(styrene-co-acrylic acid) core-shell colloids with varying diameter of the PS core and 3) poly(styrene-co-N-isopropylacrylamide) core-shell colloids with varying thickness of the poly...

  15. Polystyrene Foam EOS as a Function of Porosity and Fill Gas

    Science.gov (United States)

    Mulford, Roberta; Swift, Damian

    2009-06-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam, Differences between air-filled, nitrogen-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with plastic products during decomposition. Results differ somewhat from the conventional EOS, which are generated from values for plastic extrapolated to low densities.

  16. Study of films properties of nanocomposites recycled polystyrene and sodium bentonite

    International Nuclear Information System (INIS)

    Machado, Messias dos Santos; Valenzuela, Maria das Gracas da Silva; Telles, Victor Bridi; Valenzuela-Diaz, Francisco Rolando; Wiebeck, Helio

    2014-01-01

    The technological advances in the world induces a great use of plastics materials with growing demand. Besides this fact, the improvement of this material's uses require a special attention because of its degradation difficulties that brings environmental problems. In this work were produced films of discarded polystyrene cups and sodium bentonite, due to its property of forming nanocomposite, initially, the ratios of filler with 1, 2 and 3% with glycerol added as plasticizer. Proportions of 4, 5 and 7% were tested too, with and without addition of calcium sulfate, with the intention of observing the influences in the properties related to increases in dosage of nano load and seeks to improve the properties. The results of the analysis of characterization (XRD, DSC, SEM) indicated the possibility of recycling this material with satisfactory properties for some important applications. (author)

  17. SYNTHESIS AND POLYMERIZATION OF α-METHACRYLYOXYL-ETHYLOXYCARBONYLMETHYL- ω-(N,N-DIETHYLDITHIOCARBAMYL) POLYSTYRENE MACROMONOMERS

    Institute of Scientific and Technical Information of China (English)

    Shu-hui Qin; Kun-yuan Qiu

    2000-01-01

    Polystyrene macromonomers with different molecular weight were prepared by radical polymerization of styrene (St) in benzene using β-methacryloxylethyl 2-N,N-diethyldithiocarbamylacetate (MAEDCA) as a monomer-iniferter.Characterization of the macromonomer by 1H-NMR showed that the end groups were α-methacrylyoxylethyloxycarbonyl-methyl and ω-(N,N-diethyldithiocarbamyl). The macromonomer was difficult to homopolymerize, but it was easily copolymerized with methyl methacrylate (MMA) initiated by AIBN to form graft copolymers (PMMA-g-PSt) with PSt branches randomly distributed along the PMMA backbone. Copolymerization reaction and the structure of the graft copolymers were strongly affected by Mn and concentration of the macromonomer. The composition and Mn of the purified graft copolymer were determined by 1H-NMR and GPC analysis.

  18. 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.

  19. The application of expandable polystyrene pellets as filter media to controlled filter in a uranium mill

    International Nuclear Information System (INIS)

    Mao Ruiguo; Liu Mingde; Li Chunhua

    1987-11-01

    Expandable polystyrene pellets as filter media are used for controlled filter of uranium ore processing. Results from bench scale tests, pilot plant tests and full scale tests are satisfactory. The filter used in the full scale tests is 4 m in diameter, and the capacity is from 75 to 100 m 3 per hour. The soild content in the pregnant solution which overflowing the first thichener contains about 250 ppm of suspended solid can be reduced to 5 ∼ 10 ppm. The filter bed is backflushed with the feed liquors and the backflush returns to the countercurrent decantation circuit. The entrainment loss of the organic phase in the raffinate from solvnet extraction can be decreased by about 60% with treating the filtrated solution

  20. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability.

    Science.gov (United States)

    Yang, Seung Yun; Kim, Eung-Sam; Jeon, Gumhye; Choi, Kwan Yong; Kim, Jin Kon

    2013-04-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF4 and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF4 plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ~11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Temperature tunable micellization of polystyrene-block-poly(2-vinylpyridine) at Si-ionic liquid interface.

    Science.gov (United States)

    Lu, Haiyun; Lee, Dong Hyun; Russell, Thomas P

    2010-11-16

    Highly ordered and stable micelles formed from both symmetric and asymmetric block copolymers of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) at the Si-ionic liquid (IL) interface have been investigated by scanning force microscopy (SFM) and transmission electron microscopy (TEM). The 1-butyl-3-methylimidazolium trifluoromethanesulfonate IL, a selective and temperature-tunable solvent for the P2VP block, was used and gave rise to block copolymer micelles having different morphologies that strongly depended on the annealing temperature. The effects of film thickness, molecular weight of block copolymers, and experimental conditions, such as preannealing, rinsing, and substrate properties, on the morphologies of block copolymer micelles were also studied. In addition, spherical micelles consisting of PS core and P2VP shell could also be obtained by core-corona inversion by annealing the as-coated micellar film in the IL at high temperatures. The possible mechanism for micelle formation is discussed.

  2. 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.

  3. The properties of water in swollen cross-linked polystyrene sulfo acids

    Science.gov (United States)

    Gagarin, A. N.; Tokmachev, M. G.; Kovaleva, S. S.; Ferapontov, N. B.

    2008-11-01

    The properties of water in polystyrene sulfo acid gels with various cross-linking degrees were studied by optical volumetry and dynamic desorption porosimetry. The isotherms of water desorption obtained by dynamic desorption porosimetry coincided with isopiestic isotherms, which allowed this method to be recommended for the determination of the amount of water in polymer gels. Joint optical volumetry and dynamic desorption porosimetry studies showed that the interphase boundary in the cross-liked hydrophilic polymer-water system did not coincide with the visible gel boundary, because gels were two-phase systems, which contained water of two types, “free” and “bound.” The influence of the degree of polymer cross-linking on the amounts and properties of water of the two types was studied. It was shown that constants of water distribution in the polymer could be calculated from the dynamic desorption porosimetry data.

  4. Stress relaxation experiments on a lamellar polystyrene-polyisoprene diblock copolymer melt

    DEFF Research Database (Denmark)

    Holmqvist, P.; Castelletto, V.; Hamley, I.W.

    2001-01-01

    The non-linear rheology of the lamellar phase of a polystyrene-polyisoprene diblock copolymer is studied by oscillatory shear experiments. The relaxation of the shear modulus, G(t, gamma) is studied as a function of strain amplitude, gamma, up to large amplitude strains, gamma = 100%. The decay...... of G(t, gamma) is analysed using the model-independent CONTIN inverse Laplace transform algorithm to obtain a series of relaxation times, which reveals multiple relaxation processes. The timescale for the fastest relaxation processes is compared to those previously observed for diblock copolymer melts...... via dynamic light scattering experiments. The slowest relaxation process may be related to the shear-induced orientation of the lamellae. It is shown that time-strain separability G(t, gamma)= G(t)h(gamma) can be applied, and the damping function h(gamma) is consistent with a strongly strain...

  5. Adsorption of 2,4,6-trinitrotoluene on carboxylated porous polystyrene microspheres

    International Nuclear Information System (INIS)

    Ye Zhengfang; Meng Qingqiang; Lu Shengtao

    2012-01-01

    Large-pore-size (150 nm) polystyrene (PSt) microspheres were carboxylated with phthalic anhydride (PA) through Friedel-Crafts acetylation to study the adsorption of 2,4,6-trinitrotoluene (TNT) on this material from aqueous solution. The scanning electron microscope (SEM) images and mercury porosimetry measurements (MPM) of the microspheres showed that the pore structure was unchanged during the reaction. High adsorption capacity (11.2 mg g -1 of suction-dried adsorbent) and adsorption rate (33.9 mg g -1 h -1 ) for TNT were observed during the study. As shown by the adsorption isotherm, the adsorption of TNT on PA-PSt can be described by the Freundlich adsorption equation, indicating heterogeneous adsorption process. On-column adsorption of TNT on PA-PSt and elution indicated that TNT can be completely removed from aqueous solution and condensed into acetone.

  6. Pyrolysis of virgin and waste polypropylene and its mixtures with waste polyethylene and polystyrene.

    Science.gov (United States)

    Kiran Ciliz, Nilgun; Ekinci, Ekrem; Snape, Colin E

    2004-01-01

    A comparison of waste and virgin polypropylene (PP) plastics under slow pyrolysis conditions is presented. Moreover, mixtures of waste PP with wastes of polyethylene (PE) and polystyrene (PS) were pyrolyzed under the same operating conditions. Not only the impact of waste on degradation products but also impacts of the variations in the mixing ratio were investigated. The thermogravimetric weight loss curves and their derivatives of virgin and waste PP showed differences due to the impurities which are dirt and food residues. The liquid yield distribution concerning the aliphatic, mono-aromatic and poly-aromatic compounds varies as the ratio of PP waste increases in the waste plastic mixtures. In addition to this, the alkene/alkane ratio of gas products shows variations depending on the mixing ratio of wastes.

  7. 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

    for the functionalization were applied. The first one involved direct functionalization of the template backbone through alkylation of the phenolic groups with suitable reagents. The second modification approach was based on "click" chemistry, where the introduction of alkyne groups onto the template backbone was followed......Pairs of polystyrene-based random copolymers with balanced number of pendant basic or acidic groups were synthesized utilizing the template strategy. The same poly[(4-hydroxystyrene)-ran-styrene] was used as a template backbone for modification. Two different synthetic approaches...... 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...

  8. 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.

  9. Experimentally determined characteristics of the degree of polarization of backscattered light from polystyrene sphere suspensions

    International Nuclear Information System (INIS)

    Sun, Ping; Ma, Yongchao; Xu, Chengwei; Sun, Xiaochun; Liu, Wei

    2013-01-01

    The degree of polarization (DOP) can be used to characterize the polarization-maintaining ability of a beam of polarized light propagating through a turbid medium. Experiments on polystyrene (PST) sphere suspensions show that, the linearly polarized light propagating through the PST sphere suspension of Rayleigh scatterers has better polarization-maintaining ability, whereas the circularly polarized light propagating through the PST sphere suspension of Mie scatterers has better polarization-maintaining ability. Moreover, helicity flipping occurs to the circularly polarized light propagating in the extremely weak PST sphere suspensions or on the surface of suspensions. In addition, the DOP is dependent on the wavelength of incident light. The results can be helpful to image in turbid media by use of diffuse backscattered light. (paper)

  10. Encapsulation of hydrophobic dyes in polystyrene micro- and nanoparticles via swelling procedures.

    Science.gov (United States)

    Behnke, Thomas; Würth, Christian; Hoffmann, Katrin; Hübner, Martin; Panne, Ulrich; Resch-Genger, Ute

    2011-05-01

    Aiming at the derivation of a generalized procedure for the straightforward preparation of particles fluorescing in the visible and near-infrared (NIR) spectral region, different swelling procedures for the loading of the hydrophobic polarity-probe Nile Red into nano- and micrometer sized polystyrene particles were studied and compared with respect to the optical properties of the resulting particles. The effect of the amount of incorporated dye on the spectroscopic properties of the particles was investigated for differently sized beads with different surface chemistries, i.e., non-functionalized, amino-modified and PEG-grafted surfaces. Moreover, photostability and leaking studies were performed. The main criterion for the optimization of the dye loading procedures was a high and thermally and photochemically stable fluorescence output of the particles for the future application of these systems as fluorescent labels. © Springer Science+Business Media, LLC 2010

  11. Effect of acid treated carbon nanotubes on mechanical, rheological and thermal properties of polystyrene nanocomposites

    KAUST Repository

    Amr, Issam Thaher

    2011-09-01

    In this work, multiwall carbon nanotubes (CNT) were functionalized by acid treatment and characterized using Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Polystyrene/CNT composites of both the untreated and acid treated carbon nanotubes were prepared by thermal bulk polymerization without any initiator at different loadings of CNT. The tensile tests showed that the addition of 0.5 wt.% of acid treated CNT results in 22% increase in Young\\'s modulus. The DSC measurements showed a decrease in glass transition temperature (Tg) of PS in the composites. The rheological studies at 190 °C showed that the addition of untreated CNT increases the viscoelastic behavior of the PS matrix, while the acid treated CNT acts as plasticizer. Thermogravimetric analysis indicated that the incorporation of CNT into PS enhanced the thermal properties of the matrix polymer. © 2011 Elsevier Ltd. All rights reserved.

  12. 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.

  13. 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.

  14. Amino-modified polystyrene nanoparticles affect signalling pathways of the sea urchin (Paracentrotus lividus) embryos.

    Science.gov (United States)

    Pinsino, Annalisa; Bergami, Elisa; Della Torre, Camilla; Vannuccini, Maria Luisa; Addis, Piero; Secci, Marco; Dawson, Kenneth A; Matranga, Valeria; Corsi, Ilaria

    2017-03-01

    Polystyrene nanoparticles have been shown to pose serious risk to marine organisms including sea urchin embryos based on their surface properties and consequently behaviour in natural sea water. The aim of this study is to investigate the toxicity pathways of amino polystyrene nanoparticles (PS-NH 2 , 50 nm) in Paracentrotus lividus embryos in terms of development and signalling at both protein and gene levels. Two sub-lethal concentrations of 3 and 4 μg/mL of PS-NH 2 were used to expose sea urchin embryos in natural sea water (PS-NH 2 as aggregates of 143 ± 5 nm). At 24 and 48 h post-fertilisation (hpf) embryonic development was monitored and variations in the levels of key proteins involved in stress response and development (Hsp70, Hsp60, MnSOD, Phospho-p38 Mapk) as well as the modulation of target genes (Pl-Hsp70, Pl-Hsp60, Pl-Cytochrome b, Pl-p38 Mapk, Pl-Caspase 8, Pl-Univin) were measured. At 48 hpf various striking teratogenic effects were observed such as the occurrence of cells/masses randomly distributed, severe skeletal defects and delayed development. At 24 hpf a significant up-regulation of Pl-Hsp70, Pl-p38 Mapk, Pl-Univin and Pl-Cas8 genes was found, while at 48 hpf only for Pl-Univin was observed. Protein profile showed different patterns as a significant increase of Hsp70 and Hsp60 only after 48 hpf compared to controls. Conversely, P-p38 Mapk protein significantly increased at 24 hpf and decreased at 48 hpf. Our findings highlight that PS-NH 2 are able to disrupt sea urchin embryos development by modulating protein and gene profile providing new understandings into the signalling pathways involved.

  15. Characterization of the effects of lignin and lignin complex particles as filler on a polystyrene film

    Energy Technology Data Exchange (ETDEWEB)

    El-Zawawy, Waleed K., E-mail: wkzawawy@yahoo.com [Cellulose and Paper Department, National Research Center, El-Tahrir St., Giza (Egypt); Ibrahim, Maha M. [Cellulose and Paper Department, National Research Center, El-Tahrir St., Giza (Egypt); Belgacem, Mohamed Naceur; Dufresne, Alain [Grenoble Institute of Technology (INP) - The International School of Paper, Print Media and Biomaterials (PAGORA), BP 65, 38402 Saint Martin d' Heres cedex, Grenoble (France)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer We have studied the use of Co(II) to form a complex with the lignin. We use first vanillin as the lignin model and we observed a change in color for the produced complex depending on the light wavelength. The use of other transition metals does not give the same observation. Black-Right-Pointing-Pointer The use of the transition metal with the lignin precipitated from the black liquor after pulping of agricultural residues, gave a fluorescent color under fluorescent microscope. Black-Right-Pointing-Pointer We applied the resulted lignin complex to prepare polymer film that can be used as special polymer packaging which can be color changed under different wavelengths. - Abstract: The work in this research outlines the use of lignin precipitated from lignocellulosic substrate as fillers after modified with transition metal cations, Fe(III), Ni(II) and Co(II), in the production of a polystyrene based composite for polymer packaging applications. Virgin polystyrene was compared with lignin and lignin complex filled composites with loading of 5% by weight prepared using twin screw extrusion. The lignin complexes were first characterized by the UV spectra to identify the new absorption bands occurred due to the complex formation. Moreover, lignin model, namely vanillin, was used to notify the geometric structure of the resulting complexes applying the GC mass spectra. Scanning electron microscopy was used to indicate the change in the morphological structure of the filler particles. On the other hand, the mechanical and thermal analysis for the resulting polymer composites was studied and it was noticed that the type of lignin or lignin complex plays a roll in the results. The inclusion of the Co(II)-lignin complex was observed to increase the tensile strength of the resulting polymer composite and a decrease of the glass transition temperature. Furthermore, light wave lengths and UV fluorescent microscope were used to identify

  16. Coating carbon nanotubes with a polystyrene-based polymer protects against pulmonary toxicity.

    Science.gov (United States)

    Tabet, Lyes; Bussy, Cyrill; Setyan, Ari; Simon-Deckers, Angélique; Rossi, Michel J; Boczkowski, Jorge; Lanone, Sophie

    2011-01-21

    carbon nanotubes (CNT) can have adverse effects on health. Therefore, minimizing the risk associated with CNT exposure is of crucial importance. The aim of this work was to evaluate if coating multi-walled CNT (MWCNT) with polymers could modify their toxicity, thus representing a useful strategy to decrease adverse health effects of CNT. We used industrially-produced MWCNT uncoated (NT1) or coated (50/50 wt%) with acid-based (NT2) or polystyrene-based (NT3) polymer, and exposed murine macrophages (RAW 264.7 cell line) or Balb/c mice by intratracheal administration. Biological experiments were performed both in vitro and in vivo, examining time- and dose-dependent effects of CNT, in terms of cytotoxicity, expression of genes and proteins related to oxidative stress, inflammation and tissue remodeling, cell and lung tissue morphology (optical and transmission electron microscopy), and bronchoalveolar lavage fluid content analysis. extensive physico-chemical characterization of MWCNT was performed, and showed, although similar dimensions for the 3 MWCNT, a much smaller specific surface area for NT2 and NT3 as compared to NT1 (54.1, 34 and 227.54 m(2)/g respectively), along with different surface characteristics. MWCNT-induced cytotoxicity, oxidative stress, and inflammation were increased by acid-based and decreased by polystyrene-based polymer coating both in vitro in murine macrophages and in vivo in lung of mice monitored for 6 months. these results demonstrate that coating CNT with polymers, without affecting their intrinsic structure, may constitute a useful strategy for decreasing CNT toxicity, and may hold promise for improving occupational safety and that of general the user.

  17. Delineating fibronectin bioadhesive micropatterns by photochemical immobilization of polystyrene and poly(vinylpyrrolidone).

    Science.gov (United States)

    Sterner, Olof; Giazzon, Marta; Zürcher, Stefan; Tosatti, Samuele; Liley, Martha; Spencer, Nicholas D

    2014-01-01

    Bioadhesive micropatterns, capable of laterally confining cells to a 2D lattice, have proven effective in simulating the in vivo tissue environment. They reveal fundamental aspects of the role of adhesion in cell mechanics, proliferation, and differentiation. Here we present an approach based on photochemistry for the fabrication of synthetic polymer micropatterns. Perfluorophenyl azide (PFPA), upon deep-UV exposure, forms a reactive nitrene capable of covalently linking to a molecule that is in close proximity. PFPA has been grafted onto a backbone of poly(allyl amine), which readily forms a self-assembled monolayer on silicon wafers or glass. A film of polystyrene was applied by spin-coating, and by laterally confining the UV exposure through a chromium-on-quartz photomask, monolayers of polymers could be immobilized in circular microdomains. Poly(vinylpyrrolidone) (PVP) was attached to the background to form a barrier to nonspecific protein adsorption and cell adhesion. Micropatterns were characterized with high-lateral-resolution time-of-flight secondary ion mass spectrometry (TOF-SIMS), which confirmed the formation of polystyrene domains within a PVP background. Fluorescence-microscopy adsorption assays with rhodamine-labeled bovine serum albumin demonstrated the nonfouling efficiency of PVP and, combined with TOF-SIMS, allowed for a comprehensive characterization of the pattern geometry. The applicability of the micropatterned platform in single-cell assays was tested by culturing two cell types, WM 239 melanoma cells and SaOs-2 osteoblasts, on micropatterned glass, either with or without backfilling of the patterns with fibronectin. It was demonstrated that the platform was efficient in confining cells to the fibronectin-backfilled micropatterns for at least 48 h. PVP is thus proposed as a viable, highly stable alternative to poly(ethylene glycol) for nonfouling applications. Due to the versatility of the nitrene-insertion reaction, the platform could be

  18. Design and development of anisotropic inorganic/polystyrene nanocomposites by surface modification of zinc oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiao [School of Materials Science and Engineering, Tongji University, Shanghai 200092 (China); Research Center for Translational Medicine, East Hospital, the Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai 200092 (China); Huang, Shiming [Department of Physics, Tongji University, Shanghai 200092 (China); Wang, Yilong, E-mail: yilongwang@tongji.edu.cn [Research Center for Translational Medicine, East Hospital, the Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai 200092 (China); Shi, Donglu, E-mail: shid@ucmail.uc.edu [Research Center for Translational Medicine, East Hospital, the Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai 200092 (China); The Materials Science and Engineering Program, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH 45221 (United States)

    2016-07-01

    Anisotropic yolk/shell or Janus inorganic/polystyrene nanocomposites were prepared by combining miniemulsion polymerization and sol–gel reaction. The morphologies of the anisotropic composites were found to be greatly influenced by surface modification of zinc oxide (ZnO) nanoparticle seeds. Two different types of the oleic acid modified ZnO nanoparticles (OA-ZnO) were prepared by post-treatment of commercial ZnO powder and homemade OA-ZnO nanoparticles. The morphologies and properties of the nanocomposites were investigated by transmission electron microscope (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and energy dispersive X-ray spectroscopy (EDX). It was found that both post-treated OA-ZnO and in-situ prepared OA-ZnO nanoparticles resulted in the yolk–shell and Janus structure nanocomposites, but with varied size and morphology. These nanocomposites showed stable and strong fluorescence by introducing quantum dots as the co-seeds. The fluorescent anisotropic nanocomposites were decorated separately with surface carboxyl and hydroxyl groups. These composites with unique anisotropic properties will have high potential in biomedical applications, particularly in bio-detection. - Graphical abstract: Design and development of anisotropic inorganic/polystyrene nanocomposites by surface modification of zinc oxide nanoparticles. - Highlights: • Non-magnetic anisotropic yolk/shell or Janus nanocomposites are prepared and characterized. • Different surface modification of zinc oxide (ZnO) nanoparticles results in varied morphology and size of the final product. • Fluorescent anisotropic nanocomposites embodying quantum dots are an ideal candidate for bio-detection applications.

  19. ANIONIC SYNTHESIS OF A "CLICKABLE" MIDDLE-CHAIN AZIDEFUNCTIONALIZED POLYSTYRENE AND ITS APPLICATION IN SHAPE AMPHIPHILES

    Institute of Scientific and Technical Information of China (English)

    Kan Yue; Jinlin He; Chang Liu; Mingjun Huang; Xue-Hui Dong; Kai Guo; Peihong Ni

    2013-01-01

    "Click chemistry" is,by definition,a general functionalization methodology (GFM) and its marriage with living anionic polymerization is particularly powerful in precise macromolecular synthesis.This paper reports the synthesis of a "clickable" middle-chain azide-functionalized polystyrene (mPS-N3) by anionic polymerization and its application in the preparation of novel shape amphiphiles based on polyhedral oligomeric silsesquioxane (POSS).The mPS-N3 was synthesized by coupling living poly(styryl)lithium chains (PSLi) with 3-chloropropylmethyldichlorosilane and subsequent nucleophilic substitution of the chloro group in the presence of sodium azide.Excess PSLi was end-capped with ethylene oxide to facilitate its removal by flash chromatography.The mPS-N3 was then derived into a giant lipid-like shape amphiphile in two steps following a sequential "click" strategy.The copper(I)-catalyzed azide-alkyne cycloaddition between mPS-N3 and alkyne-functionalized vinyl-substituted POSS derivative (VPOSS-alkyne) ensured quantitative ligation to give polystyrene with VPOSS tethered at the middle of the chain (mPS-VPOSS).The thiol-ene reaction with 1-thioglycerol transforms the vinyl groups on the POSS periphery to hydroxyls,resulting in an amphiphilic shape amphiphile,mPS-DPOSS.This synthetic approach is highly efficient and modular.It demonstrates the "click" philosophy of facile complex molecule construction from a library of simple building blocks and also suggests that mPS-N3 can be used as a versatile "clickable" motif in polymer science for the precise synthesis of complex macromolecules.

  20. Fabrication and Characterization of All-Polystyrene Microfluidic Devices with Integrated Electrodes and Tubing.

    Science.gov (United States)

    Pentecost, Amber M; Martin, R Scott

    2015-01-01

    A new method of fabricating all-polystyrene devices with integrated electrodes and fluidic tubing is described. As opposed to expensive polystyrene (PS) fabrication techniques that use hot embossing and bonding with a heated lab press, this approach involves solvent-based etching of channels and lamination-based bonding of a PS cover, all of which do not need to occur in a clean room. PS has been studied as an alternative microchip substrate to PDMS, as it is more hydrophilic, biologically compatible in terms of cell adhesion, and less prone to absorption of hydrophobic molecules. The etching/lamination-based method described here results in a variety of all-PS devices, with or without electrodes and tubing. To characterize the devices, micrographs of etched channels (straight and intersected channels) were taken using confocal and scanning electron microscopy. Microchip-based electrophoresis with repetitive injections of fluorescein was conducted using a three-sided PS (etched pinched, twin-tee channel) and one-sided PDMS device. Microchip-based flow injection analysis, with dopamine and NO as analytes, was used to characterize the performance of all-PS devices with embedded tubing and electrodes. Limits of detection for dopamine and NO were 130 nM and 1.8 μM, respectively. Cell immobilization studies were also conducted to assess all-PS devices for cellular analysis. This paper demonstrates that these easy to fabricate devices can be attractive alternative to other PS fabrication methods for a wide variety of analytical and cell culture applications.

  1. Bioavailability and biodistribution of differently charged polystyrene nanoparticles upon oral exposure in rats

    International Nuclear Information System (INIS)

    Walczak, Agata P.; Hendriksen, Peter J. M.; Woutersen, Ruud A.; Zande, Meike van der; Undas, Anna K.; Helsdingen, Richard; Berg, Hans H. J. van den; Rietjens, Ivonne M. C. M.; Bouwmeester, Hans

    2015-01-01

    The likelihood of oral exposure to nanoparticles (NPs) is increasing, and it is necessary to evaluate the oral bioavailability of NPs. In vitro approaches could help reducing animal studies, but validation against in vivo studies is essential. Previously, we assessed the translocation of 50 nm polystyrene NPs of different charges (neutral, positive and negative) using a Caco-2/HT29-MTX in vitro intestinal translocation model. The NPs translocated in a surface charge-dependent manner. The present study aimed to validate this in vitro intestinal model by an in vivo study. For this, rats were orally exposed to a single dose of these polystyrene NPs and the uptake in organs was determined. A negatively charged NP was taken up more than other NPs, with the highest amounts in kidney (37.4 µg/g tissue), heart (52.8 µg/g tissue), stomach wall (98.3 µg/g tissue) and small intestinal wall (94.4 µg/g tissue). This partly confirms our in vitro findings, where the same NPs translocated to the highest extent. The estimated bioavailability of different types of NPs ranged from 0.2 to 1.7 % in vivo, which was much lower than in vitro (1.6–12.3 %). Therefore, the integrated in vitro model cannot be used for a direct prediction of the bioavailability of orally administered NPs. However, the model can be used for prioritizing NPs before further in vivo testing for risk assessment

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

    Science.gov (United States)

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

    2016-01-01

    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 the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100μg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Bioavailability and biodistribution of differently charged polystyrene nanoparticles upon oral exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Walczak, Agata P. [Wageningen University, Division of Toxicology (Netherlands); Hendriksen, Peter J. M. [RIKILT Wageningen UR (Netherlands); Woutersen, Ruud A. [TNO Earth, Life and Social Sciences (Netherlands); Zande, Meike van der; Undas, Anna K.; Helsdingen, Richard [RIKILT Wageningen UR (Netherlands); Berg, Hans H. J. van den; Rietjens, Ivonne M. C. M. [Wageningen University, Division of Toxicology (Netherlands); Bouwmeester, Hans, E-mail: hans.bouwmeester@wur.nl [RIKILT Wageningen UR (Netherlands)

    2015-05-15

    The likelihood of oral exposure to nanoparticles (NPs) is increasing, and it is necessary to evaluate the oral bioavailability of NPs. In vitro approaches could help reducing animal studies, but validation against in vivo studies is essential. Previously, we assessed the translocation of 50 nm polystyrene NPs of different charges (neutral, positive and negative) using a Caco-2/HT29-MTX in vitro intestinal translocation model. The NPs translocated in a surface charge-dependent manner. The present study aimed to validate this in vitro intestinal model by an in vivo study. For this, rats were orally exposed to a single dose of these polystyrene NPs and the uptake in organs was determined. A negatively charged NP was taken up more than other NPs, with the highest amounts in kidney (37.4 µg/g tissue), heart (52.8 µg/g tissue), stomach wall (98.3 µg/g tissue) and small intestinal wall (94.4 µg/g tissue). This partly confirms our in vitro findings, where the same NPs translocated to the highest extent. The estimated bioavailability of different types of NPs ranged from 0.2 to 1.7 % in vivo, which was much lower than in vitro (1.6–12.3 %). Therefore, the integrated in vitro model cannot be used for a direct prediction of the bioavailability of orally administered NPs. However, the model can be used for prioritizing NPs before further in vivo testing for risk assessment.

  4. Characterization of the effects of lignin and lignin complex particles as filler on a polystyrene film

    International Nuclear Information System (INIS)

    El-Zawawy, Waleed K.; Ibrahim, Maha M.; Belgacem, Mohamed Naceur; Dufresne, Alain

    2011-01-01

    Highlights: ► We have studied the use of Co(II) to form a complex with the lignin. We use first vanillin as the lignin model and we observed a change in color for the produced complex depending on the light wavelength. The use of other transition metals does not give the same observation. ► The use of the transition metal with the lignin precipitated from the black liquor after pulping of agricultural residues, gave a fluorescent color under fluorescent microscope. ► We applied the resulted lignin complex to prepare polymer film that can be used as special polymer packaging which can be color changed under different wavelengths. - Abstract: The work in this research outlines the use of lignin precipitated from lignocellulosic substrate as fillers after modified with transition metal cations, Fe(III), Ni(II) and Co(II), in the production of a polystyrene based composite for polymer packaging applications. Virgin polystyrene was compared with lignin and lignin complex filled composites with loading of 5% by weight prepared using twin screw extrusion. The lignin complexes were first characterized by the UV spectra to identify the new absorption bands occurred due to the complex formation. Moreover, lignin model, namely vanillin, was used to notify the geometric structure of the resulting complexes applying the GC mass spectra. Scanning electron microscopy was used to indicate the change in the morphological structure of the filler particles. On the other hand, the mechanical and thermal analysis for the resulting polymer composites was studied and it was noticed that the type of lignin or lignin complex plays a roll in the results. The inclusion of the Co(II)–lignin complex was observed to increase the tensile strength of the resulting polymer composite and a decrease of the glass transition temperature. Furthermore, light wave lengths and UV fluorescent microscope were used to identify the change of color for the resulting polymer film.

  5. Polystyrene-block-Poly(ionic liquid) Copolymers as Work Function Modifiers in Inverted Organic Photovoltaic Cells.

    Science.gov (United States)

    Park, Jong Baek; Isik, Mehmet; Park, Hea Jung; Jung, In Hwan; Mecerreyes, David; Hwang, Do-Hoon

    2018-02-07

    Interfacial layers play a critical role in building up the Ohmic contact between electrodes and functional layers in organic photovoltaic (OPV) solar cells. These layers are based on either inorganic oxides (ZnO and TiO 2 ) or water-soluble organic polymers such as poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)] and polyethylenimine ethoxylated (PEIE). In this work, we have developed a series of novel poly(ionic liquid) nonconjugated block copolymers for improving the performance of inverted OPV cells by using them as work function modifiers of the indium tin oxide (ITO) cathode. Four nonconjugated polyelectrolytes (n-CPEs) based on polystyrene and imidazolium poly(ionic liquid) (PSImCl) were synthesized by reversible addition-fragmentation chain transfer polymerization. The ratio of hydrophobic/hydrophilic block copolymers was varied depending on the ratio of polystyrene to the PSImCl block. The ionic density, which controls the work function of the electrode by forming an interfacial dipole between the electrode and the block copolymers, was easily tuned by simply changing the PSImCl molar ratio. The inverted OPV device with the ITO/PS 29 -b-PSImCl 60 cathode achieved the best power conversion efficiency (PCE) of 7.55% among the synthesized block copolymers, exhibiting an even higher PCE than that of the reference OPV device with PEIE (7.30%). Furthermore, the surface properties of the block copolymers films were investigated by contact angle measurements to explore the influence of the controlled hydrophobic/hydrophilic characters on the device performances.

  6. Computational study on the interactions and orientation of monoclonal human immunoglobulin G on a polystyrene surface

    Directory of Open Access Journals (Sweden)

    Javkhlantugs N

    2013-07-01

    Full Text Available Namsrai Javkhlantugs,1,2 Hexig Bayar,3 Chimed Ganzorig,1 Kazuyoshi Ueda2 1Center for Nanoscience and Nanotechnology and Department of Chemical Technology, School of Chemistry and Chemical Engineering, National University of Mongolia, Ulaanbaatar, Mongolia; 2Department of Advanced Materials Chemistry, Graduate School of Engineering, Yokohama National University, Yokohama, Japan; 3The Key Laboratory of Mammalian Reproductive Biology and Biotechnology of the Ministry of Education, Inner Mongolia University, Hohhot, Inner Mongolia Autonomous Region, People's Republic of China Abstract: Having a theoretical understanding of the orientation of immunoglobulin on an immobilized solid surface is important in biomedical pathogen-detecting systems and cellular analysis. Despite the stable adsorption of immunoglobulin on a polystyrene (PS surface that has been applied in many kinds of immunoassays, there are many uncertainties in antibody-based clinical and biological experimental methods. To understand the binding mechanism and physicochemical interactions between immunoglobulin and the PS surface at the atomic level, we investigated the binding behavior and interactions of the monoclonal immunoglobulin G (IgG on the PS surface using the computational method. In our docking simulation with the different arrangement of translational and rotational orientation of IgG onto the PS surface, three typical orientation patterns of the immunoglobulin G on the PS surface were found. We precisely analyzed these orientation patterns and clarified how the immunoglobulin G interacts with the PS surface at atomic scale in the beginning of the adsorption process. Major driving forces for the adsorption of IgG onto the PS surface come from serine (Ser, aspartic acid (Asp, and glutamic acid (Glu residues. Keywords: bionano interface, immunoassay, polystyrene, IgG, physical adsorption, simulation

  7. Damping of Mechanical Waves with Styrene/Butadiene Rubber Filled with Polystyrene Particle: Effects of Particles Size and Wave Frequency

    Directory of Open Access Journals (Sweden)

    M. Haghgo

    2007-08-01

    Full Text Available Utilizing polymeric materials for damping mechanical waves is of great importance in various fields of applications such as military camouflage, prevention of structural vibrational energy transfer, and noise attenuation. This ability originates from segmental dynamics of chain-like polymer molecules. Damping properties of styrene-butadiene rubbercontaining 10 wt% of monosize polystyrene particles with different diameters (from 80 nm to 500 μm was investigated in the frequency range of vibration, sound, and ultrasound via dynamic mechanical thermal analysis, normalsound adsorption test, and ultrasound attenuation coefficient measurement. The obtained results indicated that for different systems, containing different sizes of polystyrene particles, the area under the damping curve does not show significant change comparing to the neat SBR in the frequency range studied. However, addition of polystyrene particles, specifically nanosized particles, resulted in emergence of a secondary glass transition temperature which could be attributed to the modified dynamics of a layer of matrix molecules near the surface of PS particles. In the range of sound frequency, 0.5 to 6.3 kHz, the maximum damping was observed for the system containing polystyrene nanoparticles. However the single damping curve of neat SBR was separated into two or even three distinct curves owing to the presence of the particles. The maximum damping in the ultrasound frequency range was found for the system containing 0.5 mm polystyrene particles. This is attributed to different contributions from matrix chains dynamics and the reflection of mechanical waves from particles-matrix interface at different frequency ranges. On other words, the increase in the glass transition temperature of the elastomeric matrix phase with increasing the mechanical wave frequency causes a reduction in the contribution from matrix chains dynamics while the contribution due to diffraction from dispersed

  8. Polysaccharides for stabilization of lipid particles; Polissacarideos na estabilizacao de particulas lipidicas

    Energy Technology Data Exchange (ETDEWEB)

    Lionzo, Maria I.Z.; Silveira, Nadya P. Da, E-mail: nadya@iq.ufrgs.br [Universidade Federal do Rio Grande do Sul - UFRGS, Campus do Vale, Porto Alegre, RS (Brazil); Muniz, Edvani Curti [Departamento de Quimica, Universidade Estadual de Maringa, PR (Brazil)

    2011-07-01

    The main goal of this paper was to investigate the impact of different amounts of polyelectrolytes on the size, surface charge and rigidity of the bilayers of multilamellar liposomes. For this purpose, composite liposomes were developed containing chitosan and chondroitin sulfate. The use of a second polyelectrolyte, chondroitin sulfate, for the coating of the liposomes was applied in order to modulate their surface charge, maintaining the stability given by the presence of chitosan. Light and X-rays small angle scattering were the main techniques applied. Zeta-potential values were used to determine the charge density and the amount of adsorbed polyelectrolytes on the liposomes. (author)

  9. Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

    Directory of Open Access Journals (Sweden)

    Syed Shahabuddin

    2015-01-01

    Full Text Available Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydroxyphenylethane, a trifunctional core molecule, to give well-defined triple-arm star-branched polystyrene.

  10. Formation of Conjugated Double Bonds to Induce Polystyrene Conductivity by using Different Concentrations of Methoxo-Oxo Bis (8-Quinolyloxo Vanadium (V

    Directory of Open Access Journals (Sweden)

    Basim Mohamad Hasan

    2017-02-01

    Full Text Available The effect of different concentrations of additive compound methoxo–oxo bis (8-quinolyloxo vanadium (v on formation of conjugated double bonds as part of photo transformation of polystyrene has been investigated. The UV-Vis spectrophotometery has been used in this work. The results are show that additive concentrations applied increase the formation of conjugated double bond as compared with polystyrene. In this study methoxo – oxo bis (8-quinolyloxo vanadium (v indicates great activity to enhance the conductivity of polystyrene by formation of conjugated double bonds.

  11. Synthesis of polystyrene coated SiC nanowires as fillers in a polyurethane matrix for electromechanical conversion

    Energy Technology Data Exchange (ETDEWEB)

    Rybak, Andrzej; Warde, Micheline; Bechelany, Mikhael; Brioude, Arnaud; Toury, Berangere; Cornu, David; Miele, Philippe [Laboratoire des Multimateriaux et Interfaces, UMR 5615 CNRS, Universite Lyon 1, Universite de Lyon, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France); Beyou, Emmanuel; Chaumont, Philippe [Ingenierie des Materiaux Polymeres, UMRCNRS 5223, Laboratoire des Materiaux Polymeres et des Biomateriaux, Universite Lyon 1, Universite de Lyon, 15 Boulevard Latarget, 69622 Villeurbanne Cedex (France); Guiffard, Benoit; Seveyrat, Laurence; Guyomar, Daniel, E-mail: beyou@univ-lyon1.fr, E-mail: David.Cornu@iemm.univ-montp2.fr [Laboratoire de Genie Electrique et Ferroelectricite, LGEF-INSA Lyon, Batiment Gustave Ferrie, 8 rue de la Physique, F-69621 Villeurbanne Cedex (France)

    2010-04-09

    Grafting of polystyrene (PS) from silica coating of silicon carbide nanowires (SiCNWs) has been performed by a two-step nitroxide mediated free radical polymerization (NMP) of styrene. First, an alkoxyamine based on N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (DEPN) was covalently attached onto NWs through free surface silanol groups. To immobilize the alkoxyamine initiator on the silica surface, alkoxylamine was formed in situ by the simultaneous reaction of polymerizable acryloxy propyl trimethoxysilane (APTMS), azobis isobutyronitrile (AIBN), and DEPN, which was used as a radical trap. Polystyrene chains with controlled molecular weights and narrow polydispersity were then grown from the alkoxyamine-functionalized NWs surface in the presence of a 'free' sacrificial styrylDEPN alkoxyamine. Both the initiator and polystyrene chains were characterized by FTIR and {sup 13}C solid-state NMR and quantified by TGA. Ensuing nanocomposites were characterized by FEG-SEM, TEM and Raman spectroscopy. EDX analysis performed on functionalized nanowires during FEG-SEM analysis also gave evidence of grafting by a strong increase in the average C/Si atomic ratio. Incorporation of 2 wt% NWs into the polyurethane (PU) matrix has been carried out to prepare homogeneous nanocomposite films. The electric field induced thickness strain response has been investigated for the polystyrene-grafted silica coated SiC NWs (PU-SiC-SiO{sub 2}-PS) nanocomposites and compared to pure polyurethane film and PU-SiC-SiO{sub 2} nanocomposite without polystyrene grafting. At a moderate electric field of 10 V {mu}m{sup -1}, SiC-SiO{sub 2}-PS loading increased the strain level of pure PU by a factor of 2.2. This improvement came partially due to polystyrene grafting since PU-SiC-SiO{sub 2} films showed only a 1.7 times increase. The observed higher strain response of these nanocomposites makes them very attractive for micro-electromechanical applications.

  12. Polystyrene Plastic Waste Conversion into Liquid Fuel with Catalytic Cracking Process Using Al2O3 as Catalyst

    Directory of Open Access Journals (Sweden)

    Nurul Kholidah

    2018-01-01

    Full Text Available The increase in energy consumption and an increase in the plastic waste generation are two major problems that arise along with economic growth and the increase in population. Styrofoam is one type of polystyrene plastic waste that can be processed into liquid fuels by cracking process. In this study, the cracking process of polystyrene plastic waste into liquid fuel carried by the catalytic cracking process using Al2O3 as a catalyst. This study aimed to determine the effect of the catalyst weight, length of cracking time and range of temperature in the catalytic cracking process of polystyrene plastic waste into liquid fuel toward the mass and characteristics of liquid fuels produced and to determine the composition of liquid fuels produced. The catalytic cracking process of polystyrene plastic waste with catalyst was done in the fixed bed type reactor by heating the reactor with a heater, where the process took place at temperature of 150°C, 200°C, 250°C and 300°C and the length of the process was varied into 20, 40, and 60 minutes and the catalyst weight was also varied, which were 4%, 6% and 8%, while the styrofoam weight was 250 grams. From the research, the highest mass of liquid fuel derived from polystyrene catalytic cracking process was in the amount of 48.8 grams and liquid yield percentage of 19.5% at temperature of  250°C, cracking time of 60 minutes and weight of 8% catalyst, while the characteristics of liquid fuel that were approaching the characteristics of gasoline was at temperatures of 250°C, cracking time of 60 minutes and weight of 6% catalyst, in which each value of density of 0.763 g/ml, specific gravity of 0.778 and oAPI gravity of 50.2. While other liquid fuels obtained from the cracking of polystyrene were still within the tolerance range characteristic properties of gasoline. Liquid fuels produced from the catalytic cracking process was analyzed using a GC-MS, in which the analysis results indicated that liquid

  13. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam, E-mail: hdjeong@chonnam.ac.kr

    2014-11-14

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD.

  14. Novel synthesis of covalently linked silicon quantum dot–polystyrene hybrid materials: Silicon quantum dot–polystyrene polymers of tunable refractive index

    International Nuclear Information System (INIS)

    Choi, Jin-Kyu; Dung, Mai Xuan; Jeong, Hyun-Dam

    2014-01-01

    We present a new material design concept, silicon quantum dot (Si QD) polymers, for which surface-functionalized Si QDs can be regarded as a large monomer in the polymers. As a prototypical example, vinyl-functionalized Si QDs, i.e., divinylbenzene-capped Si QDs (DVB-Si QDs) synthesized by adopting divinylbenzene (DVB) capping molecule to the hydride-terminated Si QD (H-Si QD) via Pt-catalyzed hydrosilylation was introduced and polymerized with a styrene monomer to yield Si QD–polystyrene (Si QD–PS) polymers. To demonstrate controllability of the content of Si QDs in the polymers as in conventional polymers, three Si QD content varied Si QD–PS polymers were systematically prepared, named as Si QD–PS-A, Si QD–PS-B, and Si QD–PS-C. It has been demonstrated that the content of the Si QDs in the Si QD–PS polymers was well controlled by the amount of the DVB-Si QD used, as found to be 3.8 wt% (Si QD–PS-A), 10.0 wt% (Si QD–PS-B), 20.0 wt% (Si QD–PS-A), and 37.4 wt% (DVB-Si QD), which was deduced from TGA results. Thin films of the Si QD–PS polymers and the freestanding DVB-Si QDs were successfully fabricated by a spin-coating method and it was found that the refractive index of the thin films dried at 40 °C was linearly increased as the content of the Si QD in the polymers was increased from 1.586 (0 wt%), to 1.590 (3.8 wt%), to 1.592 (10.0 wt%), to 1.592 (20.0 wt%), and to 1.614 (37.4 wt%). - Highlights: • A new material design concept, Si QD polymer, is presented. • Freestanding vinyl-functionalized Si QD was synthesized as a monomer for polymer. • Si QD–PS polymers were synthesized by polymerization of styrene with vinyl-Si QD. • Concentration of Si QD in the polymer was well controlled by amount of Si QD used. • Refractive index of polymer thin films linearly increased with concentration of Si QD

  15. Secreted protein eco-corona mediates uptake and impacts of polystyrene nanoparticles on Daphnia magna.

    Science.gov (United States)

    Nasser, Fatima; Lynch, Iseult

    2016-03-30

    Nanoparticles (NPs) are defined as having at least one external dimension between 1 and 100 nm. Due to their small size, NPs have a large surface area to volume ratio giving them unique characteristics that differ from bulk material of the same chemical composition. As a result these novel materials have found numerous applications in medical and industrial fields with the result that environmental exposure to NPs is increasingly likely. Similarly, increased reliance on plastic, which degrades extremely slowly in the environment, is resulting in increased accumulation of micro-/nano-plastics in fresh and marine waters, whose ecotoxicological impacts are as yet poorly understood. Although NPs are well known to adsorb macromolecules from their environment, forming a biomolecule corona which changes the NP identity and how it interacts with organisms, significantly less research has been performed on the ecological corona (eco-corona). Secretion of biomolecules is a well established predator-prey response in aquatic food chains, raising the question of whether NPs interact with secreted proteins, and the impact of such interaction on NP uptake and ecotoxicity. We report here initial studies, including optimisation of protocols using carboxylic-acid and amino modified spherical polystyrene NPs, to assess interaction of NPs with biomolecules secreted by Daphnia magna and the impact of these interactions on NP uptake, retention and toxicity towards Daphnia magna. Daphnia magna are an important environmental indicator species who may be especially sensitive to nanoparticles (NPs) as a result of being filter-feeders. This paper demonstrates for the first time that proteins released by Daphnia magna create an eco-corona around polystyrene NPs which causes heightened uptake of the NPs and consequently increases toxicity. The secreted protein eco-corona also causes the NPs to be less efficiently removed from the gut of D. magna and NPs remaining in the gut of D. magna

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

    KAUST Repository

    Francis, Raju S.; Baby, Deepa K.; Gnanou, Yves

    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

  17. PREPARATION OF BLOCK COPOLYMERS OF POLY(STYRENE) AND POLY(T-BUTYL ACRYLATE) OF VARIOUS MOLECULAR WEIGHTS AND ARCHITECTURES BY ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

    Science.gov (United States)

    Block copolymers of polystyrene and poly(t-butyl acrylate) were prepared using atom transfer radical polymerization techniques. These polymers were synthesized with a CuBr/N,N,N,NAssessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Choi, Byeong Hyeok; Son, Sang Wook [Laboratory of Cell Signaling and Nanomedicine, Department of Dermatology and Division of Brain Korea 21 Project for Biomedical Science, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

    2011-07-06

    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 TiO{sub 2} 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 TiO{sub 2} 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.

  18. The Characterization and Application of Grafted Polypropylene and Polystyrene Treated with Epichlorohydrin Coupled with Cellulose or Starch for Immobilization Process

    International Nuclear Information System (INIS)

    El-Arnaouty, M.B.; Eid, M.; Dessouki, A.M.; Atia, K.S.

    2005-01-01

    The direct irradiation induced grafting of acrylamide (AAm) onto polypropylene (PP) films and polystyrene (PSty) films for crosslinking of acrylamide grafted polypropylene and polystyrene films with epichlorohydrin as spacer was studied. The reaction of polyamide-epichlorohydrin with cellulose and starch has been carried out, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermal gravimetric analysis (TGA) were carried out before and after immobilized enzyme to confirm the characterization of the polymer as well as the α- amylase enzyme immobilized one. The physico-chemical parameters of the immobilized enzymes and the kinetics of co-enzymes-polymer catalyzed reactions and stability were measured. A direct comparison was made between the products activity of the free and the immobilized preparations

  19. Effect of injection molded micro-structured polystyrene surfaces on proliferation of MC3T3-E1 cells

    Directory of Open Access Journals (Sweden)

    G. Lucchetta

    2015-04-01

    Full Text Available In this work, osteoinductive micro-pillared polystyrene surfaces were mass-produced for bone replacement applications, by means of the micro injection molding process. Firstly, the molding process parameters were optimized with a two-level, three-factor central composite face-centered plan to increase the quality of polystyrene micro pillars replication and to maximize the pillars height uniformity over the molded part. Secondly, osteoblastic MC3T3-E1 cells adhesion and proliferation on the replicated substrates were assessed as a function of micro topography parameters, such as pillars diameter, aspect ratio and spacing. Cell morphology and proliferation were evaluated through MTS test after 1, 3 and 7 days from seeding. The experimental results showed that cells adhesion and proliferation is more positively promoted on micro-pillared surfaces compared to flat surfaces, but no correlations were observed between cell proliferation and pillar diameter and spacing.

  1. 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.%.

  2. Integration of polystyrene microlenses with both convex and concave profiles in a polymer-based microfluidic system

    KAUST Repository

    Fan, Yiqiang

    2013-12-20

    This paper reports a new technique of fabricating polystyrene microlenses with both convex and concave profiles that are integrated in polymer-based microfluidic system. The polystyrene microlenses, or microlens array, are fabricated using the free-surface thermal compression molding method. The laser fabricated poly(methyl methacrylate) (PMMA) sheet is used as the mold for the thermal compression molding process. With different surface treatment methods of the PMMA mold, microlenses with either convex or concave profiles could be achieved during the thermal molding process. By integrating the microlenses in the microfluidic systems, observing the flow inside the microchannels is easier. This new technique is rapid, low cost, and it does not require cleanroom facilities. Microlenses with both convex and concave profiles can be easily fabricated and integrated in microfluidic system with this technique. © 2013 Springer-Verlag Berlin Heidelberg.

  3. Rear surface light emission measurements from laser-produced shock waves in clear and Al-coated polystyrene targets

    Science.gov (United States)

    McLean, E. A.; Deniz, A. V.; Schmitt, A. J.; Stamper, J. A.; Obenschain, S. P.; Lehecka, T.; Mostovych, A. N.; Seely, J.

    1999-08-01

    The Nike KrF laser, with its very uniform focal distributions, has been used at intensities near 10 14 W/cm 2 to launch shock waves in polystyrene targets. The rear surface visible light emission differed between clear polystyrene (CH) targets and targets with a thin (125 nm) Al coating on the rear side. The uncoated CH targets showed a relatively slowly rising emission followed by a sudden fall when the shock emerges, while the Al-coated targets showed a rapid rise in emission when the shock emerges followed by a slower fall, allowing an unambiguous determination of the time the shock arrived at the rear surface. A half-aluminized target allowed us to observe this difference in a single shot. The brightness temperature of both the aluminized targets and the non-aluminized targets was slightly below but close to rear surface temperature predictions of a hydrodynamic code. A discussion of preheat effects is given.

  4. Polymethyl methacrylate and polystyrene with layered double hydroxide nano composites: In situ synthesis, morphology and thermal properties

    International Nuclear Information System (INIS)

    Botan, Rodrigo; Nogueira, Telma R.; Lona, Liliane M.F.; Wypych, Fernando

    2011-01-01

    Over the past decade, polymer nanocomposites have attracted interest, both in industry and in academia, because they often exhibit remarkable improvement in their properties when compared with pure polymer or conventional micro and macro-composites using low levels of reinforcements. In this work polymethyl methacrylate and polystyrene reinforced with layered double hydroxide, which was intercalated with sodium dodecyl sulfate were synthesized by in situ bulk polymerization. The nanocomposites were characterized and compared by X-ray diffraction, thermogravimetric analysis and flammability test. The X-ray diffraction demonstrated that synthesized nanocomposites showed a high global dispersion of layered double hydroxide, suggesting exfoliated morphology. The result of thermogravimetric analysis and flammability test for synthesized polystyrene/ layered double hydroxide nanocomposite presented a significant improvement in thermal stability and flammability property when compared with pure polymer. (author)

  5. Intramolecular excimer formation of diastereoisomeric model compounds of polystyrene in fluid solution: their local molecular motion and photophysical properties

    International Nuclear Information System (INIS)

    Itagaki, Hideyuki; Horie, Kazuyuki; Mita, Itaru; Washio, Masakazu; Tagawa, Seiichi; Tabata, Yoneho

    1989-01-01

    The dynamic process of intramolecular excimer formation in diasteroisomeric oligomers model compounds of polystyrene, was investigated by using a picosecond pulse radiolysis technique. Monomer fluorescence of all-racemic isomers decays single-exponentially, while that of other isomers decays dual-exponentially. Multicomponent fluorescence decay curves are supposed to be mainly induced by conformational changes. The results suggest that the excimer in oligostyrenes (or polystyrene) is formed mainly in meso diad. It is definitely proved that there exists singlet energy migration in styrene trimer and tetramer systems. The conformational change in PS3 and PS4 is concluded to occur by way of cooperative motions in backbone chains bond such as a crankshaft transition, not by way of independent rotation around each carbon-carbon bond of the backbone chain. (author)

  6. Microbial degradation of high impact polystyrene (HIPS), an e-plastic with decabromodiphenyl oxide and antimony trioxide

    International Nuclear Information System (INIS)

    Sekhar, Vini C.; Nampoothiri, K. Madhavan; Mohan, Arya J.; Nair, Nimisha R.; Bhaskar, Thallada; Pandey, Ashok

    2016-01-01

    Highlights: • Biodegradation of a high impact polystyrene e − plastic. • 12.4% (w/w) e plastic film lost using an isolate, Enterobacter sp. • Noted changes in the physico-chemical characteristics of degraded e-plastic film. • Polystyrene intermediates were detected in the degradation medium. • e-plastic degrading microbes displayed extracellular depolymerase activity. - Abstract: Accumulation of electronic waste has increased catastrophically and out of that various plastic resins constitute one of the leading thrown out materials in the electronic machinery. Enrichment medium, containing high impact polystyrene (HIPS) with decabromodiphenyl oxide and antimony trioxide as sole carbon source, was used to isolate microbial cultures. The viability of these cultures in the e-plastic containing mineral medium was further confirmed by triphenyl tetrazolium chloride (TTC) reduction test. Four cultures were identified by 16S rRNA sequencing as Enterobacter sp., Citrobacter sedlakii, Alcaligenes sp. and Brevundimonas diminuta. Biodegradation experiments were carried out in flask level and gelatin supplementation (0.1% w/v) along with HIPS had increased the degradation rate to a maximum of 12.4% (w/w) within 30 days. This is the first report for this kind of material. The comparison of FTIR, NMR, and TGA analysis of original and degraded e-plastic films revealed structural changes under microbial treatment. Polystyrene degradation intermediates in the culture supernatant were also detected using HPLC analysis. The gravity of biodegradation was validated by morphological changes under scanning electron microscope. All isolates displayed depolymerase activity to substantiate enzymatic degradation of e-plastic.

  7. Bonding at Compatible and Incompatible Amorphous Interfaces of Polystyrene and Poly(Methyl Methacrylate) Below the Glass Transition Temperature

    DEFF Research Database (Denmark)

    Boiko, Yuri M.; Lyngaae-Jørgensen, Jørgen

    2004-01-01

    Films of high-molecular-weight amorphous polystyrene (PS, M-w = 225 kg/mol, M-w/M-n = 3, T-g-bulk = 97degreesC, where T-g-bulk is the glass transition temperature of the bulk sample) and poly(methyl methacrylate) (PMMA, M-w = 87 kg/mol, M-w/M-n = 2, Tg-bulk = 109degreesC) were brought into contact...

  8. Polystyrene Supported Al(OTf)3: an Environmentally Friendly Heterogeneous Catalyst for Friedel-Crafts Acylation of Aromatic Compounds

    International Nuclear Information System (INIS)

    Boroujeni, Kaveh Parvanak

    2010-01-01

    Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-Al(OTf) 3 ), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane

  9. Reflection electron energy loss spectroscopy as efficient technique for the determination of optical properties of polystyrene intermixed with gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Deris, Jamileh [Department of Physics, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Hajati, Shaaker, E-mail: Hajati@mail.yu.ac.ir [Department of Physics, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Department of Semiconductors, Materials and Energy Research Center, Karaj 3177983634 (Iran, Islamic Republic of)

    2017-01-15

    Highlights: • Reflection Electron Energy Loss Spectroscopy of nano-metalized polymer. • Determination of real part of the dielectric function of nanostructured sample. • Determination of imaginary part of the dielectric function of nanostructured sample. • Determination of refractive index and coefficient of extinction of the sample. • Determination of reflection and absorption coefficients of nano-metalized Polymer. - Abstract: The electronic properties (electron inelastic cross section, energy loss function) of a nano-metalized polystyrene obtained by reflection electron energy loss spectroscopy (REELS) in a previous study [J. Deris, S. Hajati, S. Tougaard, V. Zaporojtchenko, Appl. Surf. Sci. 377 (2016) 44–47], which relies on the Yubero-Tougaard method, were used in the complementary application of Kramers-Kronig transformation to determine its optical properties such as the real part (ε{sub 1}) and imaginary part (ε{sub 2}) of the dielectric function (ε), refractive index (n), coefficients of extinction (k), reflection (R) and absorption (μ). The degree of intermixing of polystyrene thin film and gold nanoparticles of sizes 5.5 nm was controlled by annealing the sample to achieve a morphology in which the nanoparticles were homogeneously distributed within polystyrene. It is worth noting that no data are available on the optical properties of metalized polymers such as gold nanoparticles intermixed with polystyrene. Therefore, this work is of high importance in terms of both the sample studied here and the method applied. The advantage of the method applied here is that no information on the lateral distribution of the nanocomposite sample is required. This means that the REELS technique has been presented here to suitably, efficiently and easily obtain the optical properties of such nano-metalized polymer in which the metal nanoparticles have been vertically well distributed (homogeneous in depth). Therefore, for vertically homogeneous and

  10. Microbial degradation of high impact polystyrene (HIPS), an e-plastic with decabromodiphenyl oxide and antimony trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Sekhar, Vini C. [Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695 019, Kerala (India); Nampoothiri, K. Madhavan, E-mail: madhavan85@hotmail.com [Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695 019, Kerala (India); Mohan, Arya J.; Nair, Nimisha R. [Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695 019, Kerala (India); Bhaskar, Thallada [Bio-Fuels Division (BFD), CSIR-Indian Institute of Petroleum (IIP), Dehradun, Uttarakhand 248005 (India); Pandey, Ashok [Biotechnology Division, CSIR-National Institute for Interdisciplinary Science and Technology (NIIST), Trivandrum 695 019, Kerala (India)

    2016-11-15

    Highlights: • Biodegradation of a high impact polystyrene e − plastic. • 12.4% (w/w) e plastic film lost using an isolate, Enterobacter sp. • Noted changes in the physico-chemical characteristics of degraded e-plastic film. • Polystyrene intermediates were detected in the degradation medium. • e-plastic degrading microbes displayed extracellular depolymerase activity. - Abstract: Accumulation of electronic waste has increased catastrophically and out of that various plastic resins constitute one of the leading thrown out materials in the electronic machinery. Enrichment medium, containing high impact polystyrene (HIPS) with decabromodiphenyl oxide and antimony trioxide as sole carbon source, was used to isolate microbial cultures. The viability of these cultures in the e-plastic containing mineral medium was further confirmed by triphenyl tetrazolium chloride (TTC) reduction test. Four cultures were identified by 16S rRNA sequencing as Enterobacter sp., Citrobacter sedlakii, Alcaligenes sp. and Brevundimonas diminuta. Biodegradation experiments were carried out in flask level and gelatin supplementation (0.1% w/v) along with HIPS had increased the degradation rate to a maximum of 12.4% (w/w) within 30 days. This is the first report for this kind of material. The comparison of FTIR, NMR, and TGA analysis of original and degraded e-plastic films revealed structural changes under microbial treatment. Polystyrene degradation intermediates in the culture supernatant were also detected using HPLC analysis. The gravity of biodegradation was validated by morphological changes under scanning electron microscope. All isolates displayed depolymerase activity to substantiate enzymatic degradation of e-plastic.

  11. Pyrolysis of polystyrene waste in the presence of activated carbon in conventional and microwave heating using modified thermocouple.

    Science.gov (United States)

    Prathiba, R; Shruthi, M; Miranda, Lima Rose

    2018-06-01

    Pyrolysis process was experimented using two types of heating source, namely conventional and microwave. Polystyrene (PS) plastic waste was used as feedstock in a batch reactor for both the conventional (slow pyrolysis) and microwave pyrolysis. The effect of activated carbon to polystyrene ratio on (i) yield of oil, gas and residues (ii) reaction temperature (iii) reaction time were studied. Quality of oil from pyrolysis of polystyrene were assessed for the possible applicability in fuel production. Microwave power of 450 W and polymer to activated carbon ratio of 10:1, resulted in the highest oil yield of 93.04 wt.% with a higher heating value of 45 MJ kg -1 and a kinematic viscosity of 2.7 cSt. Microwave heating when compared to conventional heating method, exhibits a reaction temperature and time of 330 °C in 5.5 min, whereas in conventional heating system it was 418 °C in 60 min. The gas chromatography-mass spectrometry analysis of liquid oil from microwave pyrolysis predominantly yields alkenes of 8.44 wt.%, α-methyl styrene 0.96 wt.%, condensed ring aromatics 23.21 wt.% and benzene derivatives 26.77 wt.% when the polystyrene to activated carbon ratio was 10:1. Significant factor of using microwave heating is the amount of energy converted (kWh) is lesser than conventional heating. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Facile graft polystyrene onto multi-walled carbon nanotubes via in situ thermo-induced radical polymerization

    International Nuclear Information System (INIS)

    Liu Peng

    2009-01-01

    A facile procedure was developed for the grafting of polystyrene onto the surfaces of multi-walled carbon nanotubes (MWNTs) via the in situ thermo-induced bulk radical polymerization of styrene at the different polymerizing temperatures, in the presence of MWNTs without any initiator added. The grafting products were validated by the dispersibility, TEM, TGA, FT-IR, and Raman analysis. The TGA results also showed the lower polymerizing temperature was propitious to the free radical addition reactions.

  13. Polystyrene-supported pyridinium chloroaluminate ionic liquid as a new heterogeneous Lewis acid catalyst for selective synthesis of benzimidazoles

    Directory of Open Access Journals (Sweden)

    Parvanak Boroujeni Kaveh

    2013-01-01

    Full Text Available Polystyrene-supported pyridinium chloroaluminate ionic liquid was prepared from the reaction of Merrifield resin with pyridine followed by reaction with aluminium chloride. This catalyst was used as a new chemoselective Lewis acid catalyst for the exclusive synthesis of 2-substituted benzimidazoles from the reaction of aldehydes with o-phenylenediamines. The catalyst is stable (as a bench top catalyst and can be easily recovered and reused without appreciable change in its efficiency.

  14. Application of “Boomerang” Linear Polystyrene-Stabilized Pd Nanoparticles to a Series of C-C Coupling Reactions in Water

    Directory of Open Access Journals (Sweden)

    Atsushi Ohtaka

    2015-02-01

    Full Text Available The application of a catch-and-release system for soluble Pd species between water (reaction medium and polystyrene (polymer support was examined in the Suzuki coupling reaction with 2-bromothiophene and the Heck reaction with styrene or bromobenzene. Although a slight increase in particle size was observed by TEM after re-stabilization of the Pd species on linear polystyrene, no agglomeration was observed.

  15. Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

    OpenAIRE

    Shahabuddin, Syed; Hamime Ismail, Fatem; Mohamad, Sharifah; Muhamad Sarih, Norazilawati

    2015-01-01

    Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydro...

  16. Grafting of Polystyrene Chains at the Edge of Graphene Nanolayers by "Grafting Through" Approach Using Reversible Addition-Fragmentation Chain Transfer Polymerization

    Directory of Open Access Journals (Sweden)

    Hossein Roghani-Mamaqani

    2017-09-01

    Full Text Available Edge-functionalized graphene nanolayers with polystyrene chains were prepared by a “grafting through” reversible addition-fragmentation chain transfer (RAFT polymerization. For this purpose, double-bond containing modifier (MD was prepared. After edge-functionalization of graphene oxide (GO by two different amounts of MD and preparation of modified graphenes (LFG and HFG, RAFT polymerization of styrene was applied for preparation of functionalized GO with different densities of polystyrene chains. Fourier transform infrared spectroscopy showed that MD and polystyrene chains were grafted at the edge of GO. Gas chromatography showed that conversion decreased by the addition of modified GO content and also grafting density of MD. Number-average molecular weight and polydispersity index of polystyrene chains were derived from gel permeation chromatography. Increase of modified graphene content results in a decrease in molecular weight of attached polystyrene chains and also an increase in their PDI value. Increase of grafting density of MD results in decrease of molecular weight of polystyrene chains with no considerable variation in PDI value. Thermogravimetric analysis results showed that char residue is about 45.1 and 46.8% for LFG and HFG, respectively. The content of degradation ascribed to polystyrene increased with increase of grafting density of MD and decreased with increase of modified graphene content. X-ray diffraction results were used for evaluation of interlayer spacing of graphene layers after functionalization process and also study of nanocomposites structure. The results of scanning electron microscopy and transmission electron microscopy show that graphene layers with high clarity turned to opaque layers with lots of creases by oxidation and attachment of polystyrene chains.

  17. Modeling of the phase equilibria of polystyrene in methylcyclohexane with semi-empirical quantum mechanical methods I.

    Science.gov (United States)

    Wilczura-Wachnik, Hanna; Jónsdóttir, Svava Osk

    2003-04-01

    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 repeating unit of the polymer, the intermolecular interaction energies between the solvent molecule and the polymer were simulated. The semiempirical quantum chemical method AM1, and a method for sampling relevant internal orientations for a pair of molecules developed previously were used. Interaction 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, and the total vapor pressures of the methylcyclohexane+ethylbenzene system were calculated. The latter system was compared to experimental data, giving qualitative agreement. Figure Solvent activities for the methylcylcohexane(1)+polystyrene(2) system at 316 K. Parameters aij (blue line) obtained with the AM1 method; parameters aij (pink line) from VLE data for the ethylbenzene+methylcyclohexane system. The abscissa is the polymer weight fraction defined as y2(x1)=(1mx1)M2/[x1M1+(1mx1)M2], where x1 is the solvent mole fraction and Mi are the molecular weights of the components.

  18. Preparation and Characterization of Wood Plastic Composite Made Up of Durian Husk Fiber and Recycled Polystyrene Foam.

    Directory of Open Access Journals (Sweden)

    Koay Seong Chun

    2018-01-01

    Full Text Available Polystyrene foam is one of the major plastic waste that hardly to recycle. The present research is aims to recycle polystyrene foam as raw material to produce wood plastic composites (WPC. The WPC was produced from recycled polystyrene (rPS and durian husk fiber (DHF using melt compound and compression moulding processes. This paper is focus on effect of fiber content on tensile and thermal properties of rPS/DHF composite. The results found the tensile strength modulus of this WPC increased at higher fiber content, but elongation at break was reduced. However, this composites exhibited an early thermal degradation when subjected to high temperature and this was commonly found among WPC. The thermal degradation of rPS/DHF composites yielded high percentage of char residue due to char formation of DHF. Overall, the rPS/DHF composites with 60 phr fiber content able to achieved strength slight above 16 MPa without any chemical treatment additives. This indicates the rPS/DHF composites can be a potential WPC if further modify with to improve its strength.

  19. Biodegradation of starch–graft–polystyrene and starch–graft–poly(methacrylic acid copolymers in model river water

    Directory of Open Access Journals (Sweden)

    Nikolić Vladimir

    2013-01-01

    Full Text Available In this paper the biodegradation study of grafted copolymers of polystyrene (PS and corn starch and poly(methacrylic acid and corn starch in model river water is described. These copolymers were obtained in the presence of different amine activators. The synthesized copolymers and products of degradation were characterized by Fourier Transform Infrared Spectroscopy (FTIR and Scanning Electron Microscopy (SEM. Biodegradation was monitored by mass decrease and number of microorganisms by Koch’s method. Biodegradation of both copolymers advanced with time, poly(methacrylic acid-graft-starch copolymers completely degraded after 21 day, and polystyrene-graft-starch partially degraded (45.78-93.09 % of total mass after 27 days. Differences in the degree of biodegradation are consequences of different structure of the samples, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. The grafting degree of PS necessary to prevent biodegradation was 54 %. Based on experimental evidence, mechanisms of both biodegradation processes are proposed, and influence of degree of starch and synthetic component of copolymers on degradation were established. [Projekat Ministarstva nauke Republike Srbije, br. 172001 i br. 172062

  20. Oriented antibody immobilization to polystyrene macrocarriers for immunoassay modified with hydrazide derivatives of poly(methacrylic acid

    Directory of Open Access Journals (Sweden)

    Vinokurova Ludmila G

    2001-08-01

    Full Text Available Abstract Background Hydrophobic polystyrene is the most common material for solid phase immunoassay. Proteins are immobilized on polystyrene by passive adsorption, which often causes considerable denaturation. Biological macromolecules were found to better retain their functional activity when immobilized on hydrophilic materials. Polyacrylamide is a common material for solid-phase carriers of biological macromolecules, including immunoreagents used in affinity chromatography. New macroformats for immunoassay modified with activated polyacrylamide derivatives seem to be promising. Results New polymeric matrices for immunoassay in the form of 0.63-cm balls which contain hydrazide functional groups on hydrophilic polymer spacer arms at their surface shell are synthesized by modification of aldehyde-containing polystyrene balls with hydrazide derivatives of poly(methacrylic acid. The beads contain up to 0.31 μmol/cm2 active hydrazide groups accessible for covalent reaction with periodate-oxidized antibodies. The matrices obtained allow carrying out the oriented antibody immobilization, which increases the functional activity of immunosorbents. Conclusions An efficient site-directed antibody immobilization on a macrosupport is realized. The polymer hydrophilic spacer arms are the most convenient and effective tools for oriented antibody coupling with molded materials. The suggested scheme can be used for the modification of any other solid supports containing electrophilic groups reacting with hydrazides.

  1. Centrifugation assay for measuring adhesion of serially passaged bovine chondrocytes to polystyrene surfaces.

    Science.gov (United States)

    Kaplan, David S; Hitchins, Victoria M; Vegella, Thomas J; Malinauskas, Richard A; Ferlin, Kimberly M; Fisher, John P; Frondoza, Carmelita G

    2012-07-01

    A major obstacle in chondrocyte-based therapy for cartilage repair is the limited availability of cells that maintain their original phenotype. Propagation of chondrocytes as monolayer cultures on polystyrene surfaces is used extensively for amplifying cell numbers. However, chondrocytes undergo a phenotypic shift when propagated in this manner and display characteristics of more adherent fibroblastic cells. Little information is available about the effect of this phenotypic shift on cellular adhesion properties. We evaluated changes in adhesion property as bovine chondrocytes were serially propagated up to five passages in monolayer culture using a centrifugation cell adhesion assay, which was based on counting of cells before and after being exposed to centrifugal dislodgement forces of 120 and 350 g. Chondrocytes proliferated well in a monolayer culture with doubling times of 2-3 days, but they appeared more fibroblastic and exhibited elongated cell morphology with continued passage. The centrifugation cell adhesion assay showed that chondrocytes became more adhesive with passage as the percentage of adherent cells after centrifugation increased and was not statistically different from the adhesion of the fibroblast cell line, L929, starting at passage 3. This increased adhesiveness correlated with a shift to a fibroblastic morphology and increased collagen I mRNA expression starting at passage 2. Our findings indicate that the centrifugation cell adhesion assay may serve as a reproducible tool to track alterations in chondrocyte phenotype during their extended propagation in culture.

  2. Fluorescent polystyrene photonic crystals self-assembled with water-soluble conjugated polyrotaxanes

    Directory of Open Access Journals (Sweden)

    Francesco Di Stasio

    2013-10-01

    Full Text Available We demonstrate control of the photoluminescence spectra and decay rates of water-soluble green-emitting conjugated polyrotaxanes by incorporating them in polystyrene opals with a stop-band spectrally tuned on the rotaxane emission (405–650 nm. We observe a suppression of the luminescence within the photonic stop-band and a corresponding enhancement of the high-energy edge (405–447 nm. Time-resolved measurements reveal a wavelength-dependent modification of the emission lifetime, which is shortened at the high-energy edge (by ∼11%, in the range 405–447 nm, but elongated within the stop-band (by ∼13%, in the range 448–482 nm. We assign both effects to the modification of the density of photonic states induced by the photonic crystal band structure. We propose the growth of fluorescent composite photonic crystals from blends of “solvent-compatible” non-covalently bonded nanosphere-polymer systems as a general method for achieving a uniform distribution of polymeric dopants in three-dimensional self-assembling photonic structures.

  3. Polystyrene star-shaped polymers made by the new In-Inmethod

    International Nuclear Information System (INIS)

    Fazeli, N.; Afshar Toromi, F.

    2002-01-01

    Three main methods are usually used for the synthesis of star-shaped polymers, where each one has its own advantages and disadvantages. Among these techniques, i n-out m ethod is the best one to produce hetero arm star polymers with narrow molecular weight distribution and long arms with active sites at the end of the second-generation arms. This method, however, has some difficulties during the synthesis of hetero-arm star polymers with styrene or dienes as the second monomers. The reason is that in the o ut s tep, the carbanions of the growing chain attack the existing double bonds of the other cores and produce an irreversible gel. The new i n-in m ethod mentioned in this paper, is used to synthesize double-star polystyrene polymers with relatively narrow molecular weight distribution and without occurrence of any gelation during the process. With the monomers, which are able to attack the existing double bonds of the cores of the star polymers, it is also possible to produce-hetero-arm star polymers using this new method

  4. Making the Tg-Confinement Effect Disappear in Thin Polystyrene Films: Good Physics vs. Inappropriate Analysis

    Science.gov (United States)

    Torkelson, John; Chen, Lawrence

    2013-03-01

    The Tg-confinement effect in polymers was first characterized in supported polystyrene (PS) films by Keddie et al. in 1994. Since then, many researchers have shown that (pseudo-)thermodynamic Tg measurements of supported PS films taken on cooling consistently yield the same qualitative results, with a decrease from bulk Tg beginning at 40-60 nm thickness and becoming very strong below 20 nm thickness. Some quantitative differences have been noted between studies, which may be ascribed to measurement method or the analysis employed. In 2004, we showed that the Tg-confinement effect in PS may be suppressed by adding several wt% of small-molecule diluents such as dioctyl phthalate. Recently, Kremer and co-workers (Macromolecules 2010, 43, 9937) reported that there was no Tg-confinement in supported PS films based on an analysis of the second derivative of ellipsometry data and use of a ninth order polynomial fit. Here, we demonstrate a new method for suppressing the Tg-confinement effect. In particular, PS made by emulsion polymerization yields no Tg-confinement effect as measured by ellipsometry or fluorescence, while PS made by anionic or conventional free radical polymerization yield strong Tg-confinement effects. The difference is hypothesized to result from surfactant in the emulsion polymerized PS. We also show that the absence of the Tg-confinement effect reported by Kremer is due to inappropriate analysis of ellipsometry data and that correct analysis yields Tg-confinement effects.

  5. Progresses in Polystyrene Biodegradation and Prospects for Solutions to Plastic Waste Pollution

    Science.gov (United States)

    Yang, S. S.; Brandon, A. M.; Xing, D. F.; Yang, J.; Pang, J. W.; Criddle, C. S.; Ren, N. Q.; Wu, W. M.

    2018-05-01

    Petroleum-based plastic pollution has been a global environmental concern for decades. The obvious contrast between the remarkable durability of the plastics and their short service time leads to the increasing accumulation of plastic wastes in the environment. A cost-effective, sustainable strategy to solve the problem should focus on source control and clean up. Polystyrene (PS) wastes, a recalcitrant plastic polymer, are among the wide spread man-made plastic pollutants. Destruction of PS wastes can be achieved using various abiotic methods such as incineration but such methods release potential air pollution and generation of hazardous by-products. Biodegradation and bioremediation has been proposed for years. Since the 1970’s, the microbial biodegradation of plastics, including PS, has been evaluated with mixed and isolated cultures from different sources such as activated sludge, trash, soil, and manure. To date, PS biodegradation by these microbial cultures is still quite slow. Recently, the larvae of yellow mealworms (Tenebrio molitor Linnaeus) have demonstrated promising PS biodegradation performance. Mealworms have demonstrated the ability to chew and ingest PS foam as food and are capable of degrading and mineralizing PS into CO2 via microbe-dependent activities within the gut in less than the 12-15 hrs gut retention time. These research results have revealed a potential for microbial biodegradation and bioremediation of plastic pollutants.

  6. Polystyrene films as barrier layers for corrosion protection of copper and copper alloys.

    Science.gov (United States)

    Románszki, Loránd; Datsenko, Iaryna; May, Zoltán; Telegdi, Judit; Nyikos, Lajos; Sand, Wolfgang

    2014-06-01

    Dip-coated polystyrene layers of sub-micrometre thickness (85-500nm) have been applied on copper and copper alloys (aluminium brass, copper-nickel 70/30), as well as on stainless steel 304, and produced an effective barrier against corrosion and adhesion of corrosion-relevant microorganisms. According to the dynamic wettability measurements, the coatings exhibited high advancing (103°), receding (79°) and equilibrium (87°) contact angles, low contact angle hysteresis (6°) and surface free energy (31mJ/m(2)). The corrosion rate of copper-nickel 70/30 alloy samples in 3.5% NaCl was as low as 3.2μm/a (44% of that of the uncoated samples), and in artificial seawater was only 0.9μm/a (29% of that of the uncoated samples). Cell adhesion was studied by fluorescence microscopy, using monoculture of Desulfovibrio alaskensis. The coatings not only decreased the corrosion rate but also markedly reduced the number of bacterial cells adhered to the coated surfaces. The PS coating on copper gave the best result, 2×10(3)cells/cm(2) (1% of that of the uncoated control). © 2013 Elsevier B.V. All rights reserved.

  7. Comparison of the cytotoxic effect of polystyrene latex nanoparticles on planktonic cells and bacterial biofilms

    International Nuclear Information System (INIS)

    Nomura, Toshiyuki; Fujisawa, Eri; Itoh, Shikibu; Konishi, Yasuhiro

    2016-01-01

    The cytotoxic effect of positively charged polystyrene latex nanoparticles (PSL NPs) was compared between planktonic bacterial cells and bacterial biofilms using confocal laser scanning microscopy, atomic force microscopy, and a colony counting method. Pseudomonas fluorescens, which is commonly used in biofilm studies, was employed as the model bacteria. We found that the negatively charged bacterial surface of the planktonic cells was almost completely covered with positively charged PSL NPs, leading to cell death, as indicated by the NP concentration being greater than that required to achieve single layer coverage. In addition, the relationship between surface coverage and cell viability of P. fluorescens cells correlated well with the findings in other bacterial cells (Escherichia coli and Lactococcuslactis). However, most of the bacterial cells that formed the biofilm were viable despite the positively charged PSL NPs being highly toxic to planktonic bacterial cells. This indicated that bacterial cells embedded in the biofilm were protected by self-produced extracellular polymeric substances (EPS) that provide resistance to antibacterial agents. In conclusion, mature biofilms covered with EPS exhibit resistance to NP toxicity as well as antibacterial agents.

  8. Comparison of the cytotoxic effect of polystyrene latex nanoparticles on planktonic cells and bacterial biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Toshiyuki, E-mail: nomura@chemeng.osakafu-u.ac.jp; Fujisawa, Eri; Itoh, Shikibu; Konishi, Yasuhiro [Osaka Prefecture University, Department of Chemical Engineering (Japan)

    2016-06-15

    The cytotoxic effect of positively charged polystyrene latex nanoparticles (PSL NPs) was compared between planktonic bacterial cells and bacterial biofilms using confocal laser scanning microscopy, atomic force microscopy, and a colony counting method. Pseudomonas fluorescens, which is commonly used in biofilm studies, was employed as the model bacteria. We found that the negatively charged bacterial surface of the planktonic cells was almost completely covered with positively charged PSL NPs, leading to cell death, as indicated by the NP concentration being greater than that required to achieve single layer coverage. In addition, the relationship between surface coverage and cell viability of P. fluorescens cells correlated well with the findings in other bacterial cells (Escherichia coli and Lactococcuslactis). However, most of the bacterial cells that formed the biofilm were viable despite the positively charged PSL NPs being highly toxic to planktonic bacterial cells. This indicated that bacterial cells embedded in the biofilm were protected by self-produced extracellular polymeric substances (EPS) that provide resistance to antibacterial agents. In conclusion, mature biofilms covered with EPS exhibit resistance to NP toxicity as well as antibacterial agents.

  9. Toward transparent nanocomposites based on polystyrene matrix and PMMA-grafted CeO2 nanoparticles.

    Science.gov (United States)

    Parlak, Onur; Demir, Mustafa M

    2011-11-01

    The association of transparent polymer and nanosized pigment particles offers attractive optical materials for various potential and existing applications. However, the particles embedded into polymers scatter light due to refractive index (RI) mismatch and reduce transparency of the resulting composite material. In this study, optical composites based on polystyrene (PS) matrix and poly(methyl methacrylate) (PMMA)-grafted CeO(2) hybrid particles were prepared. CeO(2) nanoparticles with an average diameter of 18 ± 8 nm were precipitated by treating Ce(NO(3))·6H(2)O with urea in the presence of a polymerizable surfactant, 3-methacyloxypropyltrimethoxy silane. PMMA chains were grafted on the surface of the nanoparticles upon free radical in situ solution polymerization. While blending of unmodified CeO(2) particles with PS resulted in opaque films, the transparency of the composite films was remarkably enhanced when prepared by PMMA-grafted CeO(2) hybrid particles, particularly those having a PMMA thickness of 9 nm. The improvement in transparency is presumably due to the reduction in RI mismatch between CeO(2) particles and the PS matrix when using PMMA chains at the interface.

  10. Measurement of filtration efficiency of Nuclepore filters challenged with polystyrene latex nanoparticles: experiments and modeling

    International Nuclear Information System (INIS)

    Ling, Tsz Yan; Wang Jing; Pui, David Y. H.

    2011-01-01

    Membrane filtration has been demonstrated to be effective for the removal of liquid-borne nanoparticles (NPs). Such technique can be applied to purify and disinfect drinking water as well as remove NPs in highly pure chemicals used in the industries. This study aims to study the filtration process of a model membrane filter, the Nuclepore filter. Experiments were carried out using standard filtration tools and the nanoparticle tracking analysis (NTA) technique was used to measure particle (50–500 nm) concentration upstream and downstream of the filter to determine the filtration efficiency. The NTA technique has been calibrated using 150-nm polystyrene latex particles to determine its accuracy of particle concentration measurement. Measurements were found reliable within a certain concentration limit (about 10 8 –10 10 particles/cm 3 ), which is dependent on the camera settings during the measurement. Experimental results are comparable with previously published data obtained using the aerosolization method, validating the capability of the NTA technique. The capillary tube model modified from that developed for aerosol filtration was found to be useful to represent the experimental results, when a sticking coefficient of 0.15 is incorporated. This suggests that only 15% of the particle collisions with the filter results in successful attachment. The small sticking coefficient found can be explained by the unfavorable surface interactions between the particles and the filter medium.

  11. Thermal dewetting behavior of polystyrene composite thin films with organic-modified inorganic nanoparticles.

    Science.gov (United States)

    Kubo, Masaki; Takahashi, Yosuke; Fujii, Takeshi; Liu, Yang; Sugioka, Ken-ichi; Tsukada, Takao; Minami, Kimitaka; Adschiri, Tadafumi

    2014-07-29

    The thermal dewetting of polystyrene composite thin films with oleic acid-modified CeO2 nanoparticles prepared by the supercritical hydrothermal synthesis method was investigated, varying the nanoparticle concentration (0-30 wt %), film thickness (approximately 50 and 100 nm), and surface energy of silanized silicon substrates on which the composite films were coated. The dewetting behavior of the composite thin films during thermal annealing was observed by an optical microscope. The presence of nanoparticles in the films affected the morphology of dewetting holes, and moreover suppressed the dewetting itself when the concentration was relatively high. It was revealed that there was a critical value of the surface energy of the substrate at which the dewetting occurred. In addition, the spatial distributions of nanoparticles in the composite thin films before thermal annealing were investigated using AFM and TEM. As a result, we found that most of nanoparticles segregated to the surface of the film, and that such distributions of nanoparticles contribute to the stabilization of the films, by calculating the interfacial potential of the films with nanoparticles.

  12. Glass transition in thin supported polystyrene films probed by temperature-modulated ellipsometry in vacuum.

    Science.gov (United States)

    Efremov, Mikhail Yu; Kiyanova, Anna V; Last, Julie; Soofi, Shauheen S; Thode, Christopher; Nealey, Paul F

    2012-08-01

    Glass transition in thin (1-200 nm thick) spin-cast polystyrene films on silicon surfaces is probed by ellipsometry in a controlled vacuum environment. A temperature-modulated modification of the method is used alongside a traditional linear temperature scan. A clear glass transition is detected in films with thicknesses as low as 1-2 nm. The glass transition temperature (T(g)) shows no substantial dependence on thickness for coatings greater than 20 nm. Thinner films demonstrate moderate T(g) depression achieving 18 K for thicknesses 4-7 nm. Less than 4 nm thick samples are excluded from the T(g) comparison due to significant thickness nonuniformity (surface roughness). The transition in 10-20 nm thick films demonstrates excessive broadening. For some samples, the broadened transition is clearly resolved into two separate transitions. The thickness dependence of the glass transition can be well described by a simple 2-layer model. It is also shown that T(g) depression in 5 nm thick films is not sensitive to a wide range of experimental factors including molecular weight characteristics of the polymer, specifications of solvent used for spin casting, substrate composition, and pretreatment of the substrate surface.

  13. Enhanced adhesion of osteoblastic cells on polystyrene films by independent control of surface topography and wettability

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Yun [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Eung-Sam [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Jeon, Gumhye [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Choi, Kwan Yong, E-mail: kchoi@postech.ac.kr [School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Department of Life Science, Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Kim, Jin Kon, E-mail: jkkim@postech.ac.kr [National Creative Research Center for Block Copolymer Self-Assembly, Departments of Environmental Science and Engineering and Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2013-04-01

    We independently controlled surface topography and wettability of polystyrene (PS) films by CF{sub 4} and oxygen plasma treatments, respectively, to evaluate the adhesion and proliferation of human fetal osteoblastic (hFOB) cells on the films. Among the CF{sub 4} plasma-treated PS films with the average surface roughness ranging from 0.9 to 70 nm, the highest adhesion of hFOB cells was observed on a PS film with roughness of ∼ 11 nm. When this film was additionally treated by oxygen plasma to provide a hydrophilic surface with a contact angle less than 10°, the proliferation of bone-forming cell was further enhanced. Thus, the plasma-based independent modification of PS film into an optimum nanotexture for human osteoblast cells could be appplied to materials used in bone tissue engineering. Highlights: ► New approach based on plasma treatment to independently control the surface topography and wettability ► The adhesion of human fetal osteoblast (hFOB) was enhanced on a surface with an average roughness of ∼ 11 nm. ► The adhesion and proliferation of hFOB was maximized when nanotextured surface became highly hydrophilic.

  14. Preparation, characterization, biological activity, and transport study of polystyrene based calcium–barium phosphate composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Mohammad Mujahid Ali; Rafiuddin,, E-mail: rafi_amu@rediffmail.com

    2013-10-15

    Calcium–barium phosphate (CBP) composite membrane with 25% polystyrene was prepared by co-precipitation method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and Thermogravimetric analysis (TGA) were used to characterize the membrane. The membrane was found to be crystalline in nature with consistent arrangement of particles and no indication of visible cracks. The electrical potentials measured across the composite membrane in contact with univalent electrolytes (KCl, NaCl and LiCl), have been found to increase with decrease in concentrations. Thus the membrane was found to be cation-selective. Transport properties of developed membranes may be utilized for the efficient desalination of saline water and more importantly demineralization process. The antibacterial study of this composite membrane shows good results for killing the disease causing bacteria along with waste water treatment. Highlights: • Transport properties of composite membrane are evaluated. • The composite membrane was found to be stable in all media. • TMS method is used for electrochemical characterization. • The membrane was found to be cation selective. • The order of surface charge density was found to be LiCl < NaCl < KCl.

  15. Pathway analysis of systemic transcriptome responses to injected polystyrene particles in zebrafish larvae.

    Science.gov (United States)

    Veneman, Wouter J; Spaink, Herman P; Brun, Nadja R; Bosker, Thijs; Vijver, Martina G

    2017-09-01

    Microplastics are a contaminant of emergent concern in the environment, however, to date there is a limited understanding on their movement within organisms and the response of organisms. In the current study zebrafish embryos at different development stages were exposed to 700nm fluorescent polystyrene (PS) particles and the response pathway after exposure was investigated using imaging and transcriptomics. Our results show limited spreading of particles within the larvae after injection during the blastula stage. This is in contrast to injection of PS particles in the yolk of 2-day old embryos, which resulted in redistribution of the PS particles throughout the bloodstream, and accumulation in the heart region. Although injection was local, the transcriptome profiling showed strong responses of zebrafish embryos exposed to PS particle, indicating a systemic response. We found several biological pathways activated which are related to an immune response in the PS exposed zebrafish larvae. Most notably the complement system was enriched as indicated by upregulation of genes in the alternative complement pathway (e.g. cfhl3, cfhl4, cfb and c9). The fact that complement pathway is activated indicates that plastic microparticles are integrated in immunological recognition processes. This was supported by fluorescence microscopy results, in which we observed co-localisation of neutrophils and macrophages around the PS particles. Identifying these key events can be a first building block to the development of an adverse outcome pathway (AOP). These data subsequently can be used within ecological and human risk assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Nano Petri dishes: a new polystyrene platform for studying cell-nanoengineered surface interactions

    International Nuclear Information System (INIS)

    Cha, Kyoung Je; Na, Moon-Hee; Kim, Hyung Woo; Kim, Dong Sung

    2014-01-01

    In this study, we fabricated and fully characterized a new type of polystyrene (PS) cell-culture platform containing nanoengineered surfaces (NES), referred to as a nano Petri dish, which can be used at the transition stage of basic cell–NES interaction studies for clinical applications. Nano-injection molding in this study was used for the mass production of the nano Petri dish having nanopore arrays. The effects of processing parameters of the injection molding on the replication quality of the nanopore arrays were quantitatively evaluated by means of design of experiments based on the Taguchi method. This allowed efficient and reliable cell culture studies by providing large numbers of the same dishes, in addition to removing the fixation step of the NES plates inside the cell-culture container. Physical, chemical and mechanical properties of the NES, as well as cell behavior including attachment and proliferation of human osteosarcoma MG-63 cells on the NES, were then characterized, with and without the oxygen plasma surface treatment. (paper)

  17. Nano Petri dishes: a new polystyrene platform for studying cell-nanoengineered surface interactions

    Science.gov (United States)

    Cha, Kyoung Je; Na, Moon-Hee; Kim, Hyung Woo; Kim, Dong Sung

    2014-05-01

    In this study, we fabricated and fully characterized a new type of polystyrene (PS) cell-culture platform containing nanoengineered surfaces (NES), referred to as a nano Petri dish, which can be used at the transition stage of basic cell-NES interaction studies for clinical applications. Nano-injection molding in this study was used for the mass production of the nano Petri dish having nanopore arrays. The effects of processing parameters of the injection molding on the replication quality of the nanopore arrays were quantitatively evaluated by means of design of experiments based on the Taguchi method. This allowed efficient and reliable cell culture studies by providing large numbers of the same dishes, in addition to removing the fixation step of the NES plates inside the cell-culture container. Physical, chemical and mechanical properties of the NES, as well as cell behavior including attachment and proliferation of human osteosarcoma MG-63 cells on the NES, were then characterized, with and without the oxygen plasma surface treatment.

  18. Frustrated total internal reflection in organic light-emitting diodes employing sphere cavity embedded in polystyrene

    International Nuclear Information System (INIS)

    Zhu, Peifen

    2016-01-01

    The light extraction efficiency of top-emitting organic light-emitting diodes (OLEDs) is numerically investigated employing the finite-difference time-domain method. The periodic nanostructures formed by embedding the sphere arrays in polystyrene (PS) are placed on top of OLED to frustrate the total internal reflection at the interface between OLED and free space. These nanostructures serve as an intermediate medium to extract the light out of OLED devices. Efficiently coupling both evanescent waves and propagation waves into spheres and subsequently extracting these light waves out of the sphere is key to achieving high extraction efficiency. By tuning the thickness of PS layer, both of the in-coupling efficiency and out-coupling efficiency are optimized for achieving high light extraction efficiency. Thicker PS layer results in higher in-coupling efficiency in sphere while the thinner PS layer leads to higher out-coupling efficiency. Thus the maximum light extraction is a trade-off between the in-coupling efficiency and out-coupling efficiency. The study shows that light extraction efficiency of 89% can be achieved by embedding 0.90 μm TiO 2 sphere in 0.30 μm PS layer with optimized in-coupling efficiency, out-coupling efficiency and cavity effect. (paper)

  19. Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis.

    Science.gov (United States)

    Phuc, Le Thi Minh; Taniguchi, Akiyoshi

    2017-06-19

    The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF) on the uptake efficiency of polystyrene nanoparticles (PS NPs) by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs) indicated that cellular uptake of PS NPs is related to the binding of EGF-EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications.

  20. Epidermal Growth Factor Enhances Cellular Uptake of Polystyrene Nanoparticles by Clathrin-Mediated Endocytosis

    Directory of Open Access Journals (Sweden)

    Le Thi Minh Phuc

    2017-06-01

    Full Text Available The interaction between nanoparticles and cells has been studied extensively, but most research has focused on the effect of various nanoparticle characteristics, such as size, morphology, and surface charge, on the cellular uptake of nanoparticles. In contrast, there have been very few studies to assess the influence of cellular factors, such as growth factor responses, on the cellular uptake efficiency of nanoparticles. The aim of this study was to clarify the effects of epidermal growth factor (EGF on the uptake efficiency of polystyrene nanoparticles (PS NPs by A431 cells, a human carcinoma epithelial cell line. The results showed that EGF enhanced the uptake efficiency of A431 cells for PS NPs. In addition, inhibition and localization studies of PS NPs and EGF receptors (EGFRs indicated that cellular uptake of PS NPs is related to the binding of EGF–EGFR complex and PS NPs. Different pathways are used to enter the cells depending on the presence or absence of EGF. In the presence of EGF, cellular uptake of PS NPs is via clathrin-mediated endocytosis, whereas, in the absence of EGF, uptake of PS NPs does not involve clathrin-mediated endocytosis. Our findings indicate that EGF enhances cellular uptake of PS NPs by clathrin-mediated endocytosis. This result could be important for developing safe nanoparticles and their safe use in medical applications.