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Sample records for cupc-doped pmma thin

  1. Impact of X-ray irradiation on PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Saman, E-mail: saman.khan343@gmail.com [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Rafique, Muhammad Shahid [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Anjum, Safia [Physics Department, Lahore College for Woman University, Lahore (Pakistan); Hayat, Asma [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Iqbal, Nida [Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia (UTM) (Malaysia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer PMMA thin films were deposited at 300 Degree-Sign C and 500 Degree-Sign C using PLD technique. Black-Right-Pointing-Pointer These films were irradiated with different fluence of laser produced X-rays. Black-Right-Pointing-Pointer Irradiation affects the ordered packing as well as surface morphology of film. Black-Right-Pointing-Pointer Hardness of film decreases up to certain value of X-ray fluence. Black-Right-Pointing-Pointer Absorption in UV-visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 Degree-Sign C and 500 Degree-Sign C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm{sup -2}. Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV-vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 Degree-Sign C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 Degree-Sign C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV-visible region.

  2. Formation of hydrated layers in PMMA thin films in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Akers, Peter W. [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); Nelson, Andrew R.J. [The Bragg Institute, Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia); Williams, David E. [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington (New Zealand); McGillivray, Duncan J., E-mail: d.mcgillivray@auckland.ac.nz [School of Chemical Sciences, University of Auckland, Auckland (New Zealand); MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington (New Zealand)

    2015-10-30

    Graphical abstract: - Highlights: • Homogeneous thin PMMA films prepared on Si/SiOx substrates and measured in air and water. • Reproducible formation of highly hydrated layer containing 50% water at the PMMA/SiOx interface. • When heated the films swell at 50 °C without loss of material. • Upon re-cooling to 25 °C the surface roughens and material is lost. - Abstract: Neutron reflectometry (NR) measurements have been made on thin (70–150 Å) poly(methylmethacrylate) (PMMA) films on Si/SiOx substrates in aqueous conditions, and compared with parameters measured using ellipsometry and X-Ray reflectometry (XRR) on dry films. All techniques show that the thin films prepared using spin-coating techniques were uniform and had low roughness at both the silicon and subphase interfaces, and similar surface energetics to thicker PMMA films. In aqueous solution, NR measurements at 25 °C showed that PMMA forms a partially hydrated layer at the SiOx interface 10 Å under the film, while the bulk film remains intact and contains around 4% water. Both the PMMA film layer and the sublayer showed minimal swelling over a period of 24 h. At 50 °C, PMMA films in aqueous solution roughen and swell, without loss of PMMA material at the surface. After cooling back to 25 °C, swelling and roughening increases further, with loss of material from the PMMA layer.

  3. Influence of Doping Concentration on Dielectric, Optical, and Morphological Properties of PMMA Thin Films

    Directory of Open Access Journals (Sweden)

    Lyly Nyl Ismail

    2012-01-01

    Full Text Available PMMA thin films were deposited by sol gel spin coating method on ITO substrates. Toluene was used as the solvent to dissolve the PMMA powder. The PMMA concentration was varied from 30 ~ 120 mg. The dielectric properties were measured at frequency of 0 ~ 100 kHz. The dielectric permittivity was in the range of 7.3 to 7.5 which decreased as the PMMA concentration increased. The dielectric loss is in the range of 0.01 ~ –0.01. All samples show dielectric characteristics which have dielectric loss is less than 0.05. The optical properties for thin films were measured at room temperature across 200 ~ 1000 nm wavelength region. All samples are highly transparent. The energy band gaps are in the range of 3.6 eV to 3.9 eV when the PMMA concentration increased. The morphologies of the samples show that all samples are uniform and the surface roughness increased as the concentration increased. From this study, it is known that, the dielectric, optical, and morphology properties were influenced by the amount of PMMA concentration in the solution.

  4. Spin Coated Nano Scale PMMA Films for Organic Thin Film Transistors

    Science.gov (United States)

    Shekar, B. Chandar; Sathish, S.; Sengoden, R.

    Nano scale poly methyl methacrylate (PMMA) films are prepared by spin coating the solution of PMMA on to p-Si substrate. The thickness of the films coated is measured by Ellipsometry. The SA-XRD spectrum of the as grown and annealed films indicated the amorphous nature. The SEM analysis revealed no pinholes, pits and dendritic features on the surface. Both as grown and annealed films indicated smooth surface and amorphous structure. The capacitance-voltage (C-V) behaviour of the metal-insulator-semiconductor (MIS) structure with Al/PMMA/p-Si has been studied. The C-V behaviour carried out for various frequencies (f) ranging from 20 kHz to 1 MHz and for a bias voltage range of -20 V to +20 V. Both as grown and annealed films showed a small flat band voltage (VFB) shift towards the negative voltage. The small shift in the VFB observed may be due to charge traps and de-traps. The obtained C-V behaviour for as grown and annealed films indicated that as grown PMMA nano scale thin films do not have many defects such as voids and inhomogeneity etc. The observed C-V behavior, a very low shift in the flat band voltage (VFB 0); reasonably higher dielectric constant values; thermal stability up to 2800C; amorphous and smooth surface implies that nano scale thin PMMA film coated by spin coating could be used as an efficient dielectric layer in field effect organic thin film transistors (OTFTs).

  5. Microdomain orientation dependence on thickness in thin films of cylinder-forming PS-b-PMMA.

    Science.gov (United States)

    Zucchi, I A; Poliani, E; Perego, M

    2010-05-07

    The self-assembly of block-copolymer thin films in periodic nanostructures has received considerable attention during the last decade due to their potential applications in nanofabrication and nanolithography. We followed the morphologies developed in thin films of a cylinder-forming diblock copolymer polystyrene-b-poly(methylmethacrylate) ((PS-b-PMMA), PS 46.1 kg mol( - 1), PMMA 21.0 kg mol( - 1), lattice spacing L(0) = 36 nm), as a function of the film thickness (t), analyzing the effect of thickness commensurability on domain orientation in respect to the substrate. The study was circumscribed to the unexplored range of thickness below L(0). Two thickness windows with perpendicular orientation of the PMMA domains were identified: a well-known window at t approximately L(0) and a new window at t approximately L(0)/2. A half-parallel cylinder morphology was observed for [Formula: see text] with a progressive change in morphology [Formula: see text] when thickness increases from L(0)/2 to L(0). This experimental evidence provides new insights on the mechanism of block copolymers self-organization and indicates the possibility to tune the thickness of the nanostructured polymeric film below L(0), allowing the fabrication of ultrathin soft masks for advanced lithographic processes.

  6. Organic Thin Film Field Effect Transistors with PMMA-GMA Gate Dielectric

    Institute of Scientific and Technical Information of China (English)

    JIANG Wen-Hai; DU Guo-Tong; YU Shu-Kun; WANG Wei; CHANG Yu-Chun; WANG Xu

    2006-01-01

    @@ We fabricate organic thin films using the copolymer of methyl methacrylate and glycidyl methacrylate (PMMA-GMA) as a gate dielectric with a simple top-contact structure. Copper phthalocyanine (CuPc) TFTs are fabricated and the influences of annealing on the performance are studied. The mobilities increase from 2.5 ×103 cm2/Vs to 4.2 × 103 cm2/Vs and threshold voltages decrease from -18 V to -10 V after annealing. The good performances of the devices approach those obtained with inorganic gate dielectric materials such as silicon dioxide under the same technical conditions. It is fully proven that PMMA-GMA is a competitive candidate as an excellent gate insulation layer.

  7. Opposed-Flow Flame Spread in a Narrow Channel Apparatus over Thin PMMA Sheets

    Science.gov (United States)

    Bornand, G. R.; Olson, Sandra L.; Miller, F. J.; Pepper, J. M.; Wichman, I. S.

    2013-01-01

    Flame spread tests have been conducted over polymethylmethacrylate (PMMA) samples in San Diego State University's Narrow Channel Apparatus (SDSU NCA). The Narrow Channel Apparatus (NCA) has the ability to suppress buoyant flow in horizontally spreading flames, and is currently being investigated as a possible replacement or complement to NASA's current material flammability test standard for non-metallic solids, NASA-STD-(I)-6001B Test 1. The buoyant suppression achieved with a NCA allows for tests to be conducted in a simulated microgravity atmosphere-a characteristic that Test 1 lacks since flames present in Test 1 are buoyantly driven. The SDSU NCA allows for flame spread tests to be conducted with varying opposed flow oxidizer velocities, oxygen percent by volume, and total pressure. Also, since the test sample is placed symmetrically between two confining plates so that there is a gap above and below the sample, this gap can be adjusted. This gap height adjustment allows for a compromise between heat loss from the flame to the confining boundaries and buoyancy suppression achieved by those boundaries. This article explores the effect gap height has on the flame spread rate for 75 µm thick PMMA at 1 atm pressure and 21% oxygen concentration by volume in the SDSU NCA. Flame spread results from the SDSU NCA for thin cellulose fuels have previously been compared to results from tests in actual microgravity at various test conditions with the same sample materials and were found to be in good agreement. This article also presents results from the SDSU NCA for PMMA at 1 atm pressure, opposed oxidizer velocity ranging from 3 to 35 cm/s, oxygen concentration by volume at 21%, 30 %, and 50% and fuel thicknesses of 50 and 75 µm. These results are compared to results obtained in actual microgravity for PMMA obtained at the 4.5s drop tower of MGLAB in Gifu, Japan, and the 5.2s drop tower at NASA's Zero-Gravity Research Facility in Cleveland, OH. This comparison confirms

  8. Thin-Film LSCs Based on PMMA Nanohybrid Coatings: Device Optimization and Outdoor Performance

    Directory of Open Access Journals (Sweden)

    S. M. El-Bashir

    2013-01-01

    Full Text Available This study concerns the design optimization of thin-film luminescent solar concentrators (TLSCs based on polymethylmethacrylate (PMMA/silica nanohybrid films doped with coumarin dyestuffs specialized in coloring plastics. Two designs of TLSCs had been prepared and characterized. The first consists of a transparent nanohybrid layer coated on a fluorescent PMMA substrate. The second design is the ordinary configuration in which fluorescent nanohybrid layer is coated on a transparent PMMA substrate. The investigation of the spectral properties and efficiency parameters recommended the best solar energy conversion efficiency for the second design. The outdoor performance of optimized TLSC was also evaluated under clear sky conditions of Riyadh city, and the hourly values of the optical efficiency, ηopt, were calculated for one year. The best performance was achieved in summer since the short circuit current for PV cell was doubled after being attached to TLSC and the value of ηopt reached 40% which is higher than other values recorded before due to the abundant solar energy potential in the Arabian Peninsula.

  9. Characterization study on machining PMMA thin-film using AFM tip-based dynamic plowing lithography.

    Science.gov (United States)

    Yan, Yongda; He, Yang; Geng, Yanquan; Hu, Zhenjiang; Zhao, Xuesen

    2016-11-01

    This paper presents a reliable nanolithography technique, namely dynamic plowing lithography (DPL) based on a commercial atomic force microscope (AFM). The poly(methyl methacrylate) (PMMA) solution spinning on a silicon substrate is utilized to be scratched directly with an oscillating tip at its resonance frequency. The films with different thickness are obtained by adjusting the concentration of solution and post baked time. A new silicon tip is employed to conduct DPL on PMMA film surface. The geometry of nano-line structure scratched on the film with high adhesion force is shown with a transition process, including total protuberance, protuberance with groove and groove with pile-up. The scratching direction has less influence on the scratched depth of groove, while the shape of pile-up is varied with directions. The depth of groove on thin films is increasing with the drive amplitude until the value of the depth reaches to the threshold value. Moreover, owing to smaller elastic modulus, the film with relatively large thickness could be modified by the tip more easily using this DPL method. SCANNING 38:612-618, 2016. © 2016 Wiley Periodicals, Inc.

  10. Understanding the Mechanism of Solvent-Mediated Adhesion of Vacuum Deposited Au and Pt Thin Films onto PMMA Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Alan K [ORNL; Brown, Victoria L. [James Madison University; Rugg, Brandon K. [James Madison University; Devore, Prof. Thomas C. [James Madison University; Meyer III, Harry M [ORNL; Hu, Dr. Xiaofeng [James Madison University; Hughes, Prof. W. Christopher [James Madison University; Augustine, Prof. Brian H. [James Madison University

    2012-01-01

    The adhesion of 100 nm thick electron-beam deposited Au and Pt and magnetron sputtered Au thin films onto poly(methyl methacrylate) (PMMA) substrates can be significantly enhanced to over 90% adhesion by either spin-casting or vapor-exposure to hydrohalocarbon solvents prior to metal deposition compared to samples that are either cleaned in isopropyl alcohol or pre-treated with a remote O2 plasma. X-ray photoelectron spectroscopy (XPS) and evolved gas Fourier transform infrared spectroscopy (EGA-FTIR) reveal the presence of residual halogenated solvent molecules at the PMMA surface which chemically activates the surface to produce a stable chemical interaction between the noble metal film and the PMMA. Density functional theory (DFT) calculations show that the halogenated solvent molecules preferentially form a Lewis acid-base adduct with the oxygen atoms in the ester group in PMMA which is consistent with the measured enthalpy of desorption of chloroform (CHCl3) on PMMA determined by EGA-FTIR to be 36 kJ mol-1. The DFT model also supports the experimentally observed change in the high resolution XPS O 1s peak at 533.77 eV after metallization attributed to a change in the local bonding environment of the bridging O in the PMMA ester group. DFT also predicts that the deposited metal atom (M) inserts into the C-X bond where X is the halogen atom on either CHCl3 or bromoform (CHBr3) to form a O M X interaction that is observed by a M-X bond in the high resolution XPS Cl 2p3/2 peak at 198.03 eV and Br 3p3/2 peak at 182.06 eV. A range of solvents with differing polarities for PMMA pre-treatment have been used and it is proposed that non-complexing solvents result in significant metal adhesion improvement. The Gutmann acceptor number can be used to predict the effectiveness of solvent treatment for noble metal adhesion. A model is proposed in which the bond energy of the C-X bond of the solvent must be sufficiently low so that the C-X bond can be cleaved to form the M

  11. Structure and Plasmonic Properties of Thin PMMA Layers with Ion-Synthesized Ag Nanoparticles

    DEFF Research Database (Denmark)

    Popok, Vladimir; Hanif, Muhammad; Mackova, Anna;

    2015-01-01

    Silver nanoparticles are synthesized in polymethylmethacrylate (PMMA) by 30 keV Ag+ ion implantation with high fluences. The implantation is accompanied by structural and compositional evolution of the polymer as well as sputtering. The latter causes towering of the shallow nucleated Ag nanoparti......Silver nanoparticles are synthesized in polymethylmethacrylate (PMMA) by 30 keV Ag+ ion implantation with high fluences. The implantation is accompanied by structural and compositional evolution of the polymer as well as sputtering. The latter causes towering of the shallow nucleated Ag...... nanoparticles above the surface. The synthesized nanoparticles can be split into two groups: (i) located at the surface and (ii) fully embedded in the shallow layer. These two groups provide corresponding spectral bands related to localized surface plasmon resonance. The bands demonstrate considerable intensity...... making the synthesized composites promising for plasmonic applications....

  12. Oxygen loss induced by swift heavy ions of low and high dE/dx in PMMA thin films

    Science.gov (United States)

    Thomaz, R.; Gutierres, L. I.; Morais, J.; Louette, P.; Severin, D.; Trautmann, C.; Pireaux, J. J.; Papaléo, R. M.

    2015-12-01

    Investigations on the chemical modifications induced by swift heavy ions in PMMA thin films were carried out using beams of high dE/dx (2.2 GeV Bi, 14,090 eV/nm) and low dE/dx (2 MeV H, 19 eV/nm). The induced chemical modifications were monitored by XPS for films with initial thickness of 50 and 100 nm. For both beams, the irradiation decreased the amount of carbon atoms bound to oxygen (Cdbnd O and Csbnd Osbnd C), with a larger decrease of the carboxyl moiety, as expected. However, the chemical changes induced by light and heavy ions were qualitatively different. For the same mean deposited energy density, proton irradiation induced a decrease of the relative intensity of the carbon-oxygen bonds up to ∼20% larger than the irradiation with Bi ions. This suggests a greater importance of particle ejection by unzipping of PMMA chains at high dE/dx, which tends to keep the O/C ratio closer to the pristine value.

  13. Oxygen loss induced by swift heavy ions of low and high dE/dx in PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Thomaz, R.; Gutierres, L.I. [Faculdade de Física, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga 6681, 90619-900 Porto Alegre (Brazil); Morais, J. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Av Bento Gonçalves 9500, 91501-970 Porto Alegre (Brazil); Louette, P. [Université de Namur, Rue de Bruxelles 61, 5000 Namur (Belgium); Severin, D. [Materials Research, GSI Helmholtz Centre, Planckstr. 1, 64291 Darmstadt (Germany); Trautmann, C. [Materials Research, GSI Helmholtz Centre, Planckstr. 1, 64291 Darmstadt (Germany); Technische Universität Darmstadt, Alarich-Weiss-Straße2, 64287 Darmstadt (Germany); Pireaux, J.J. [Université de Namur, Rue de Bruxelles 61, 5000 Namur (Belgium); Papaléo, R.M. [Faculdade de Física, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga 6681, 90619-900 Porto Alegre (Brazil)

    2015-12-15

    Investigations on the chemical modifications induced by swift heavy ions in PMMA thin films were carried out using beams of high dE/dx (2.2 GeV Bi, 14,090 eV/nm) and low dE/dx (2 MeV H, 19 eV/nm). The induced chemical modifications were monitored by XPS for films with initial thickness of 50 and 100 nm. For both beams, the irradiation decreased the amount of carbon atoms bound to oxygen (C=O and C−O−C), with a larger decrease of the carboxyl moiety, as expected. However, the chemical changes induced by light and heavy ions were qualitatively different. For the same mean deposited energy density, proton irradiation induced a decrease of the relative intensity of the carbon–oxygen bonds up to ∼20% larger than the irradiation with Bi ions. This suggests a greater importance of particle ejection by unzipping of PMMA chains at high dE/dx, which tends to keep the O/C ratio closer to the pristine value.

  14. Synthesis, characterization and femtosecond nonlinear saturable absorption behavior of copper phthalocyanine nanocrystals doped-PMMA polymer thin films

    Science.gov (United States)

    Zongo, S.; Dhlamini, M. S.; Neethling, P. H.; Yao, A.; Maaza, M.; Sahraoui, B.

    2015-12-01

    In this work, we report the femtosecond nonlinear saturable absorption response of synthesized copper phthalocyanine nanocrystals (CPc-NCs)-doped PMMA polymer thin films. The samples were initially characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-Vis and scanning electron microscopy (SEM) techniques. The crystalline phase and morphological analysis revealed nanocrystals of monoclinic structure with an average crystallite size between 31.38 nm and 42.5 nm. The femtosecond Z-scan study at 800 nm central wavelength indicated a saturable absorption behavior of which the mechanism is closely related to the surface plasmon resonance (SPR) of the particles. This nonlinear effect could potentially make the CPc-NCs useful in nonlinear optical devices.

  15. Wavelength dependence of reversible photodegradation of disperse orange 11 dye-doped PMMA thin films

    CERN Document Server

    Anderson, Benjamin R; Kuzyk, Mark G

    2015-01-01

    Using transmittance imaging microscopy we measure the wavelength dependence of reversible photodegradation in disperse orange 11 (DO11) dye-doped (poly)methyl-methacrylate (PMMA). The reversible and irreversible inverse quantum efficiencies (IQEs) are found to be constant over the spectral region investigated, with the average reversible IQE being $\\overline{B}_\\alpha= 8.70 (\\pm 0.38)\\times 10^5$ and the average irreversible IQE being $\\overline{B}_\\epsilon= 1.396 (\\pm 0.031)\\times 10^8$. The large difference between the IQEs is hypothesized to be due to the reversible decay channel being a direct decay mechanism of the dye, while the irreversible decay channel is an indirect mechanism, with the dye first absorbing light, then heating the surrounding environment causing polymer chain scission and cross linking. Additionally, the DO11/PMMA's irreversible IQE is found to be among the largest of those reported for organic dyes, implying that the system is highly photostable. We also find that the recovery rate i...

  16. EFFECT OF PHOTOOXIDATION ON PHOTOLUMINESCENCE OF N, N'-DIPHENYL-N, N'-DI(M-TOLYL)-BENZIDINE AND RUBRENE CODOPED PMMA THIN FILMS

    Institute of Scientific and Technical Information of China (English)

    Y.B. Hou; L.J. Meng; M.P. dos Santos

    2001-01-01

    In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidineand rubrene were fabricated by spin coating, and the effect of photooxidation onthe photoluminescence of the doped PMMA thin films was investigated. The resultsshowed that under the irradiation of 350nm UV light, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine can sensitized rubrene and results in the enhancement in the photooxrationof rubrene. The effect of photooxidation on the photoluminescence from rubrene w asmore obvious. Both lifetime measurement and in situ measurement of photolumines-cence showed that rubrene molecules exist in two chemical surroundings.

  17. Hydroxyapatite thin films synthesized by pulsed laser deposition and magnetron sputtering on PMMA substrates for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Socol, G. [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Macovei, A.M. [Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 060031 Bucharest (Romania); Miroiu, F.; Stefan, N.; Duta, L.; Dorcioman, G. [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Mihailescu, I.N., E-mail: ion.mihailescu@inflpr.ro [National Institute for Lasers, Plasma, and Radiation Physics, Atomistilor Street 409, RO-77125 Magurele, Ilfov (Romania); Petrescu, S.M. [Institute of Biochemistry, Romanian Academy, Splaiul Independentei 296, 060031 Bucharest (Romania); Stan, G.E.; Marcov, D.A. [National Institute of Materials Physics, 105 bis Atomistilor Street, RO-77125 Bucharest-Magurele (Romania); Chiriac, A.; Poeata, I. [' Prof. Dr. N. Oblu' , Emergency Clinical Hospital, Neurosurgery Department, Ateneului Street, 3, 700309 Iasi (Romania)

    2010-05-25

    Functionalized implants represent an advanced approaching in implantology, aiming to improve the biointegration and the long-term success of surgical procedures. We report on the synthesis of hydroxyapatite (HA) thin films on polymethylmetacrylate (PMMA) substrates - used as cranio-spinal implant-type structures - by two alternative methods: pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (MS). The deposition parameters were optimized in order to avoid the substrate overheating. Stoichiometric HA structures were obtained by PLD with incident laser fluences of 1.4-2.75 J/cm{sup 2}, pressures of 30-46.66 Pa and 10 Hz pulses repetition rate. The MS depositions were performed at constant pressure of 0.3 Pa in inert and reactive atmospheres. SEM-EDS, XRD, FTIR and pull-out measurements were performed assessing the apatitic-type structure of the prepared films along with their satisfactory mechanical adhesion. Cell viability, proliferation and adhesion tests in osteosarcoma SaOs2 cell cultures were performed to validate the bioactive behaviour of the structures and to select the most favourable deposition regimes. For PLD, this requires a low fluence of 1.4 J/cm{sup 2}, reduced pressure of water vapours and a 100 {sup o}C/4 h thermal treatment. For MS, the best results were obtained for 80% Ar + 20% O{sub 2} reactive atmosphere at low RF power ({approx}75 W). Cells grown on these coatings exhibit behaviour similar to those grown on the standard borosilicate glass control: increased viability, good proliferation, and optimal cell adhesion. In vitro tests proved that HA/PMMA neurosurgical structures prepared by PLD and MS are compatible for the interaction with human bone cells.

  18. All-optical ultrafast logic gates based on saturable to reverse saturable absorption transition in CuPc-doped PMMA thin films

    Science.gov (United States)

    Roy, Sukhdev; Yadav, Chandresh

    2011-09-01

    A detailed theoretical analysis of femtosecond transition from saturable (SA) to reverse saturable absorption (RSA) has been carried out in Copper-Phthalocyanine (CuPc)-doped polymethylmethacrylate (PMMA) thin films. The transition due to fifth-order effect of excited-state absorption induced two-photon process has been optimized with respect to intensity, concentration and nonlinear coefficients to design various all-optical logic gates, namely, OR and AND at lower intensities (SA region), XOR at the transition intensity, and the universal NAND and NOR at higher intensities (RSA region). The advantages of ultrafast operation, simplicity, tunability, high contrast, stability of CuPc-doped PMMA thin film, and the possibility to control and realize various logic operations in the same film at the same wavelength by only controlling the pulse intensity, instead of a pump-probe configuration, make them attractive for practical implementation.

  19. Synthesis and Properties of High Strength Thin Film Composites of Poly(ethylene Oxide) and PEO-PMMA Blend with Cetylpyridinium Chloride Modified Clay

    OpenAIRE

    Mohammad Saleem Khan; Sabiha Sultana

    2015-01-01

    Ion-conducting thin film composites of polymer electrolytes were prepared by mixing high MW poly(ethylene oxide) (PEO), poly(methyl methacrylate) (PMMA) as a polymer matrix, cetylpyridinium chloride (CPC) modified MMT as filler, and different content of LiClO4 by using solution cast method. The crystallinity, ionic conductivity (σ), and mechanical properties of the composite electrolytes and blend composites were evaluated by using XRD, AC impedance, and UTM studies, respectively. The modific...

  20. Fabrication of resistive switching memory based on solution processed PMMA-HfO x blended thin films

    Science.gov (United States)

    Lee, Jae-Won; Cho, Won-Ju

    2017-02-01

    In this study, we developed PMMA-HfO x blended resistive random access memory (ReRAM) devices using solution processing to overcome the drawbacks of the individual organic and inorganic materials. Resistive switching behaviors of solution-processed PMMA, PMMA-HfO x , and HfO x film-based ReRAM devices were investigated. The poor electrical characteristic of PMMA and brittle mechanical properties of HfO x can be improved by blending PMMA and HfO x together. The PMMA-HfO x blended ReRAM device exhibited a larger memory window, stable endurance and retention, a lower operation power, and better set/reset voltage distributions. Furthermore, these new systems featured multilevel conduction states at different reset bias for non-volatile multilevel memory applications. Therefore, solution-processed PMMA-HfO x blended films are a promising material for non-volatile memory devices on flexible or wearable electronic systems.

  1. Synthesis and Properties of High Strength Thin Film Composites of Poly(ethylene Oxide and PEO-PMMA Blend with Cetylpyridinium Chloride Modified Clay

    Directory of Open Access Journals (Sweden)

    Mohammad Saleem Khan

    2015-01-01

    Full Text Available Ion-conducting thin film composites of polymer electrolytes were prepared by mixing high MW poly(ethylene oxide (PEO, poly(methyl methacrylate (PMMA as a polymer matrix, cetylpyridinium chloride (CPC modified MMT as filler, and different content of LiClO4 by using solution cast method. The crystallinity, ionic conductivity (σ, and mechanical properties of the composite electrolytes and blend composites were evaluated by using XRD, AC impedance, and UTM studies, respectively. The modification of clay by CPC showed enhancement in the d-spacing. The loading of clay has effect on crystallinity of PEO systems. Blend composites showed better mechanical properties. Young’s modulus and elongation at break values showed increase with salt and clay incorporation in pure PEO. The optimum composition composite of PEO with 3.5 wt% of salt and 3.3 wt% of CPMMT exhibited better performance.

  2. Effect of Grafting Density of Random Copolymer Brushes on Perpendicular Alignment in PS-b-PMMA Thin Films

    KAUST Repository

    Lee, Wooseop

    2017-07-18

    We modulated the grafting density (σ) of a random copolymer brush of poly(styrene-r-methyl methacrylate) on substrates to probe its effect on the formation of perpendicularly aligned lamellae of polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA). Supported by coarse-grained simulation results, we hypothesized that an increase in σ will allow us to systematically tune the block copolymer interfacial interactions with the substrates from being preferential to one of the blocks to being neutral toward both blocks and will thereby facilitate enhanced regimes of perpendicularly aligned lamellae. We verified such a hypothesis by using a simple grafting-to approach to modify the substrates and characterized the thickness window for perpendicular lamellae as a function of brush thickness (or σ) on the grafted substrates using scanning force microscopy (SFM) images and grazing incidence small-angle X-ray scattering (GISAXS) measurements. The experimental results validated our hypothesis and suggested that the σ of random copolymer brushes can be used as an additional versatile parameter to modulate the interfacial interactions and the resulting alignment of block copolymer films.

  3. Thin-Film Behavior of Poly(methyl methacrylates). 2. An FT-IR Study of Langmuir-Blodgett Films of Isotactic PMMA

    NARCIS (Netherlands)

    Brinkhuis, R.H.G.; Schouten, A.J.

    1991-01-01

    The structure of Langmuir-Blodgett films of isotactic PMMA transferred to substrates was investigated with FT-infrared techniques. From the results it is argued that at high surface pressures, the isotactic PMMA is transferred in a crystalline-like conformation, presumably as double helices. The fil

  4. The influence of an electric field on photodegradation and self healing in disperse orange 11 dye-doped PMMA thin films

    CERN Document Server

    Anderson, Benjamin; Kuzyk, Mark G

    2013-01-01

    The influence of an applied electric field on reversible photodegradation of disperse orange 11 (DO11) doped into PMMA is measured using digital imaging and conductivity measurements. Correlations between optical imaging, which measures photodegradation and recovery, and photoconductivity enables an association to be made between the damaged fragments and their contribution to current, thus establishing that damaged fragments are charged species, or polarizable. Hence, the decay and recovery process should be controllable with the applications of an electric field. Indeed, we find that the dye polymer system is highly sensitive to an applied electric field, which drastically affects the decay and recovery dynamics. We demonstrate accelerated recovery when one field polarity is applied during burning, and the opposite polarity is applied during recovery. This work suggests that the damage threshold can be increased through electric field conditioning; and, the results are qualitatively consistent with the doma...

  5. Bonding PMMA microfluidics using commercial microwave ovens

    Science.gov (United States)

    Toossi, A.; Moghadas, H.; Daneshmand, M.; Sameoto, D.

    2015-08-01

    In this paper, a novel low-cost, rapid substrate-bonding technique is successfully applied to polymethyl methacrylate (PMMA) microfluidics bonding for the first time. This technique uses a thin intermediate metallic microwave susceptor layer at the interface of the bonding site (microchannels) which produces localized heating required for bonding during microwave irradiation. The metallic susceptor pattern is designed using a multiphysics simulation model developed in ANSYS Multiphysics software (high-frequency structural simulation (HFSS) coupled with ANSYS-Thermal). In our experiments, the required microwave energy for bonding is delivered using a relatively inexpensive, widely accessible commercial microwave oven. Using this technique, simple PMMA microfluidics prototypes are successfully bonded and sealed in less than 35 seconds with a minimum measured bond strength of 1.375 MPa.

  6. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  7. Signals of chaotic behavior in PMMA

    CERN Document Server

    Hacinliyan, A; Sahin, G; Akin, G

    2003-01-01

    The time evolution of the current passing through PMMA polymer thin films under 10 V at 23 deg. C (296 K) was sampled at intervals ranging from 1 to 20 s. The data showed chaotic behavior in the context of pinned charge density waves [Phys. Rev. B 41 (1990) 11522]. The resultant time series has been analyzed by means of TISEAN, time series analysis software [The TISEAN package CHAOS 9 (1999) 413]. The analysis has revealed a positive maximal Lyapunov exponent. This is also corroborated by a calculation of the fractal dimension and application of the Kaplan-Yorke conjecture. In the analysis two widely separated time scales have been observed; the first zero crossing of the correlation function at 8380 s and the first marked minimum of the average mutual information at 40 s.

  8. Ferroelectric phase diagram of PVDF:PMMA

    NARCIS (Netherlands)

    Li, M.; Stingelin, N.; Michels, J.J.; Spijkman, M.-J.; Asadi, K.; Feldman, K.; Blom, P.W.M.; Leeuw, D.M. de

    2012-01-01

    We have investigated the ferroelectric phase diagram of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA). The binary nonequilibrium temperature composition diagram was determined and melting of α- and β-phase PVDF was identified. Ferroelectric β-PVDF:PMMA blend films were made b

  9. Ferroelectric Phase Diagram of PVDF : PMMA

    NARCIS (Netherlands)

    Li, Mengyuan; Stingelin, Natalie; Michels, Jasper J.; Spijkman, Mark-Jan; Asadi, Kamal; Feldman, Kirill; Blom, Paul W. M.; de Leeuw, Dago M.

    2012-01-01

    We have investigated the ferroelectric phase diagram of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA). The binary nonequilibrium temperature composition diagram was determined and melting of alpha- and beta-phase PVDF was identified. Ferroelectric beta-PVDF:PMMA blend films w

  10. Fabrication of Prototype of Artificial Retina Adapted to a Curved Image Plane Based on Arrayed PMMA Microfibers

    Directory of Open Access Journals (Sweden)

    Jian Hong Chen

    2011-05-01

    Full Text Available The traditional visual prosthesis combines both a camera and an electrode array implanted on the visual neural networks. Here, we introduce a new design of artificial retina which integrate the transmission of image and the electrical stimulation of cortical neurons on a single PMMA micro fiber. It is comprised of multiple PMMA microfibers with both ends connected with one flexible and one rigid substrates. The flexible one is a PDMS mold of microrods and ready to conform to a curved image plane. The rigid one is in the form of a silica plate coated with a PMMA thin film and could be attached to a CMOS image sensor for the evaluation of its optical performance. The multiple PMMA microfibers were directly drawn from liquid PMMA thin film with PDMS rods. With arrayed PMMA microfibers, the image planes could be transferred from the flexible to rigid substrate. Each PMMA microfiber delivers a part of the image the PDMS mold transmits. Incorporated with O/E convertors, each micro fiber could function as an unit of electrical stimulation in accordance with part of the image the artificial retina delivered and is ready to function as a cortical neural prosthesis in the future application.

  11. Electrical conductivity of polyaniline doped PVC–PMMA polymer blends

    Indian Academy of Sciences (India)

    S H Deshmukh; D K Burghate; V P Akhare; V S Deogaonkar; P T Deshmukh; M S Deshmukh

    2007-02-01

    The electrical conductivity of polyaniline doped polyvinylchloride (PVC) and poly(methyl methacrylate) (PMMA) thin films has been measured by studying the – characteristics at various temperatures in the range 323–363 K. The results are presented in the form of – characteristics and analysis has been made by interpretation of Poole–Frenkel, Fowler–Nordheim, Schottky ln() vs plots, Richardson and Arrhenius plots. The analysis of these results suggests that Schottky and Richardson mechanisms are primarily responsible for the observed conduction.

  12. Influence of Acetylacetone on Photocatalytic Properties of TiO2 Thin Films Deposited on PMMA Substrates%乙酰丙酮对PMMA负载锐钛矿型TiO2薄膜及其光催化性能影响

    Institute of Scientific and Technical Information of China (English)

    张志清; 黄剑锋; 曹丽云; 吴建鹏

    2011-01-01

    The nanociystalline TiO2 solution was prepared using a microwave hydrotheimal process to treat precursor liquid which was obtained by control the hydrolysis of titanium-n-butoxide in the presence of excessive water and acetylacetone (AcAcH). Then nanociystalline TiO2 thin films were deposited on polymethylmethacrylate (PMMA) substrates by dip-coating process from TiO2 colloidal solution. The phase composition of TiO2 nanoparticles, morphologies and optical properties of TiO2 thin films deposited on PMMA substrates were characterized by X-ray diffraction (XRD), fourier transform infrared spectrometer (FTTR), transmission electron microscope (TEM), atomic force microscopy (AFM) and UV-vis spectroscopy. Meanwhile photocatalytic properties of TiO2 films were investigated by degradation of Rhodamine B ( RhB) under ultraviolet radiation. Trie results indicate that anatase TiO2 colloidal solution modified by AcAcH is disperse, uniform, deposit-free and the deposited TiO2 thin films are transparent, homogeneous and compact, and show high efficiency of photocatalysis. Rhodamine B has been degradated over 90% at 180 min%以钛酸丁酯作为钛源,水为溶剂,乙酰丙酮(AcAcH)为表面修饰剂,采用微波水热辅助溶胶-凝胶法制备了纳米晶二氧化钛水溶液,利用提拉镀膜法在聚合物聚甲基丙烯酸甲酯(PMMA)基板上沉积得到了透明TiO2纳米晶薄膜.通过X射线衍射(XRD)、红外光谱(FTIR)、透射电子显微镜(TEM)、原子力显微镜(AFM)和紫外-可见光吸收光谱(UV-Vis)等对TiO2纳米颗粒和薄膜的晶相组成、表面形貌及光学性能进行表征.同时通过紫外光光催化降解罗丹明B研究了TiO2薄膜的光催化性能.结果表明:通过引入乙酰丙酮,可以得到高度分散、晶相为锐钛矿型的TiO2水溶胶,在PMMA基板上沉积得到的薄膜表面平整、致密,具有良好的透光率,经过180 min紫外光照射,对罗丹明B的降解率达到90%以上.

  13. Enriching PMMA nanospheres with adjustable charges as novel templates for multicolored dye-PMMA nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xumei; Xu Shuping; Xu Weiqing [State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012 (China); Liang Chongyang; Li Hongrui; Sun Fei, E-mail: xuwq@jlu.edu.cn [Institute of Frontier Medical Science, Jilin University, Changchun 130021 (China)

    2011-07-08

    Multicolored fluorescent dye loaded PMMA nanospheres were synthesized by the electrostatic adsorption of dye molecules on the charged PMMA nanospheres, whose charges were adjusted by choosing different initiators. The charged PMMA nanospheres have a wider capacity and advantage for combining the charged dyes. The fluorescent dye-PMMA composite nanospheres possess the advantages of higher brightness, longer lifetime and stronger resistance to photobleaching relative to dye molecules. Dye leakage remained lower than 5% over one week. These fluorescent nanospheres have been used in biological labels in cell imaging. They can easily stain blood cancer cells without further surface modification.

  14. Facile synthesis of monodisperse superparamagnetic Fe3O4/PMMA composite nanospheres with high magnetization

    Science.gov (United States)

    Lan, Fang; Liu, Ke-Xia; Jiang, Wen; Zeng, Xiao-Bo; Wu, Yao; Gu, Zhong-Wei

    2011-06-01

    Monodisperse superparamagnetic Fe3O4/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe3O4/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe3O4/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe3O4 nanoparticles. VSM and TGA showed that the Fe3O4/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g - 1 (total mass), which was only decreased by 17% compared with the initial bare Fe3O4 nanoparticles.

  15. Characterization of advanced polymethylmethacrylate (PMMA) targets for TNSA laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Torrisi, L., E-mail: Lorenzo.Torrisi@unime.it [Department of Physics and Earth Science, Messina University, V.le F.S. d’Alcontres 31, 98166 S. Agata, Messina (Italy); Cutroneo, M.; Semian, V. [Nuclear Physics Institute, ASCR, 250 68 Rez (Czech Republic); Ceccio, G. [Department of Physics and Earth Science, Messina University, V.le F.S. d’Alcontres 31, 98166 S. Agata, Messina (Italy)

    2015-10-01

    Highlights: • The manuscript presents the procedure to prepare thin advanced targets based on PMMA polymer in order to obtain high ion acceleration in laser-generated plasma. • The manuscript is original for the procedures of polymer preparation and preliminary techniques used. - Abstract: Characterization of advanced micrometric foils suitable for TNSA regime were performed using optical spectroscopy, microscopy and Nd:YAG low laser intensity. Micrometric acrylic beads were produced in polymethylmethacrylate foils through complex physical and technical procedures in order to enhance the absorption coefficient in the IR region. Moreover, Au nanoparticles were embedded in the polymer in order to induce surface plasmon resonance absorption and plasma electron density enhancement. The suitably prepared polymers were investigated at low laser intensity to have evidence of their capability to absorb IR wavelength radiations and promote enhancement of the plasma temperature and density. Results indicate that the high transparence of PMMA foils can be strongly reduced by the presences of the micrometric acrylic beads and that the obtainable laser-generated plasma improves the ion acceleration when high beads density and high Au nanoparticles concentrations are employed.

  16. Study of the gamma irradiation effects on the PMMA/HA and PMMA/SW

    Science.gov (United States)

    Silva, P.; Albano, C.; Perera, R.; Domínguez, N.

    2010-03-01

    The behavior of the poly(methyl methacrylate) (PMMA) under the action of gamma radiation has been sufficiently studied. In this work, we present results from melt flow index (MFI), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electron paramagnetic resonance (EPR) of PMMA composites with hydroxyapatite (HA) and seaweed residues (SW) irradiated with gamma rays at 1.08 kGy/h. Composites of PMMA/HA and PMMA/SW with 10%, 20% and 30% of the filler were prepared. The results show an increase in the MFI values with the integral dose of radiation, being consistent with chain-scission reactions. No EPR signal was observed in pure PMMA, while in the composites, the typical EPR signal of the PMMA radicals was observed, which increased with the amount of HA or SW. When comparing the relative intensities of the EPR signals for both types of composites, a slight increase in the concentration of free radicals generated in the sample with SW respect to that of PMMA/HA composite was obtained. A decay of the total free radical concentration was observed as time elapsed.

  17. Study of the gamma irradiation effects on the PMMA/HA and PMMA/SW

    Energy Technology Data Exchange (ETDEWEB)

    Silva, P., E-mail: silva@ivic.v [Instituto Venezolano de Investigaciones Cientificas, Centro de Fisica, Carretera Panamericana Km. 11, Caracas 1020-A (Venezuela, Bolivarian Republic of); Albano, C. [Universidad Central de Venezuela, Facultad de Ingenieria (Venezuela, Bolivarian Republic of); Instituto Venezolano de Investigaciones Cientificas, Centro de Quimica (Venezuela, Bolivarian Republic of); Perera, R. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas 1080-A (Venezuela, Bolivarian Republic of); Dominguez, N. [Instituto Venezolano de Investigaciones Cientificas, Centro de Quimica (Venezuela, Bolivarian Republic of)

    2010-03-15

    The behavior of the poly(methyl methacrylate) (PMMA) under the action of gamma radiation has been sufficiently studied. In this work, we present results from melt flow index (MFI), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electron paramagnetic resonance (EPR) of PMMA composites with hydroxyapatite (HA) and seaweed residues (SW) irradiated with gamma rays at 1.08 kGy/h. Composites of PMMA/HA and PMMA/SW with 10%, 20% and 30% of the filler were prepared. The results show an increase in the MFI values with the integral dose of radiation, being consistent with chain-scission reactions. No EPR signal was observed in pure PMMA, while in the composites, the typical EPR signal of the PMMA radicals was observed, which increased with the amount of HA or SW. When comparing the relative intensities of the EPR signals for both types of composites, a slight increase in the concentration of free radicals generated in the sample with SW respect to that of PMMA/HA composite was obtained. A decay of the total free radical concentration was observed as time elapsed.

  18. Multiwavelength optical storage of diarylethene PMMA films

    Science.gov (United States)

    Guo, Haobo; Zhang, Fushi; Sun, Fan; Pu, Shouzhi; Zhou, Xinhong

    2003-04-01

    Current applied optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene molecules dispersed into PMMA together was used as storage material. The recording layer was spin-coated on a glass substrate with Al reflective layer. Two laser beams of 532 nm and 650 nm were used in recording and readout by simultaneously writing and reading, and the reading lasers detected signals with high S/N ratio. Multi-wavelength storage was realized with the diarylethene PMMA film.

  19. Improved osteoblast response to UV-irradiated PMMA/TiO2 nanocomposites with controllable wettability.

    Science.gov (United States)

    Shayan, Mahdis; Jung, Youngsoo; Huang, Po-Shun; Moradi, Marzyeh; Plakseychuk, Anton Y; Lee, Jung-Kun; Shankar, Ravi; Chun, Youngjae

    2014-12-01

    Osteoblast response was evaluated with polymethylmethacrylate (PMMA)/titanium dioxide (TiO2) nanocomposite thin films that exhibit the controllable wettability with ultraviolet (UV) treatment. In this study, three samples of PMMA/TiO2 were fabricated with three different compositional volume ratios (i.e., 25/75, 50/50, and 75/25) followed by UV treatment for 0, 4, and 8 h. All samples showed the increased hydrophilicity after UV irradiation. The films fabricated with the greater amount of TiO2 and treated with the longer UV irradiation time increased the hydrophilicity more. The partial elimination of PMMA on the surface after UV irradiation created a durable hydrophilic surface by (1) exposing higher amount of TiO2 on the surface, (2) increasing the hydroxyl groups on the TiO2 surface, and (3) producing a mesoporous structure that helps to hold the water molecules on the surface longer. The partial elimination of PMMA on the surface was confirmed by Fourier transform infrared spectroscopy. Surface profiler and atomic force microscopy demonstrated the increased surface roughness after UV irradiation. Both scanning electron microscopy and energy-dispersive X-ray spectroscopy demonstrated that particles containing calcium and phosphate elements appeared on the 8 h UV-treated surface of PMMA/TiO2 25/75 samples after 4 days soaking in Dulbecco's Modified Eagle Medium. UV treatment showed the osteoblast adhesion improved on all the surfaces. While all UV-treated hydrophilic samples demonstrated the improvement of osteoblast cell adhesion, the PMMA/TiO2 25/75 sample after 8 h UV irradiation (n = 5, P value = 0.000) represented the best cellular response as compared to other samples. UV-treated PMMA/TiO2 nanocomposite thin films with controllable surface properties represent a high potential for the biomaterials used in both orthopedic and dental applications.

  20. PMMA/PMMA core-shell particles with ellipsoidal, fluorescent cores: accessing rotational dynamics.

    Science.gov (United States)

    Klein, Matthias K; Klinkenberg, Nele; Schuetter, Stefan; Saenger, Nicolai; Pfleiderer, Patrick; Zumbusch, Andreas

    2015-03-10

    For several decades, nonaqueous dispersions of PMMA particles have played an important role in colloid research. They have found application as colloidal model systems, which are used to probe glassy dynamics or to explore crystal nucleation. To date, most research has focused on spherical particles, in which only translational motion can be investigated. Recently, however, there has been a surge of interest in analyzing also rotational dynamics. In this contribution, we introduce a new class of core-shell particles, which can be used as rotational probes. The colloids described herein are composed of shape anisotropic, fluorescent cores covered with nonfluorescent PMMA shells. The core-shell particles are built up in four steps. In a first step, we produce fluorescent and photo-cross-linkable PMMA colloids. In the second step, these particles are thermomechanically elongated and fixed in defined ellipsoidal shapes by photo-cross-linking. Subsequently, we cover the cross-linked, fluorescent core with a nonfluorescent PMMA shell. The shape of the resulting core-shell colloids is tunable between the initial anisotropic and perfect spherical shape. For shaping, we apply a simple solvent swelling procedure. As one option, this method yields perfect PMMA spheres with ellipsoidal, fluorescent centers. We also report morphological particle characterization using various fluorescence microscopy techniques. Finally, we demonstrate that the rotational dynamics of individual colloids can be tracked and analyzed.

  1. Thermal degradation of PMMA in fluidised beds.

    Science.gov (United States)

    Smolders, K; Baeyens, J

    2004-01-01

    In recent years, the production and consumption of plastics have increased significantly and wastes are commonly incinerated or dumped in a landfill. Plastics pyrolysis, on the other hand, may provide an alternative means for disposal of plastic wastes with recovery of valuable gasoline-range hydrocarbons or the monomer. Pyrolysis of polymethyl methacrylate (PMMA) may result in very high recycling rates (90-98%) of the monomer methylmethacrylate (MMA) since the cracking of MMA to lighter molecules (CO2, CO and light hydrocarbons) is limited. The MMA-yield is mainly dependent on the residence time of the gas in the reactor and to a lesser extent on the operating temperature. The paper presents experimental work performed in a lead bath and in a fluidised bed. At low temperatures, the reaction is kinetically controlled, whereas at high temperatures, heat transfer restricts the overall reaction rate. It was demonstrated that the heat transfer in the fluid bed could be estimated by the equation of Kothari. A design procedure for a fluid bed PMMA-depolymerisation reactor is outlined and illustrated for a process of 1 tpd PMMA.

  2. A Facile Method for the Synthesis Fluorescent Zinc Chalcogenide (ZnO, ZnS and ZnSe) Nanoparticles in PS and PMMA Polymer Matrix.

    Science.gov (United States)

    Hariharan, P S; Subhashini, N; Vasanthalakshmi, J; Anthony, Savarimuthu Philip

    2016-03-01

    A simple method for the synthesis of fluorescent zinc chalcogenide (ZnO, ZnS and ZnSe) nanoparticles directly in the transparent PMMA and PS polymer matrices were reported. Highly dispersed small spherical ZnO nanoparticles (3-5 nm) was obtained by hydrothermal reaction of PMMA/PS-Zn(acac)2H2O in toluene. ZnS and ZnSe nanoparticles were prepared by heterogeneous stirring of PMMA/PS-Zn(acac)2H2O in toluene with aqueous solution of thiourea or NaHSe. Interestingly, ZnO and ZnS-PMMA thin film showed strong fluorescence quenching upon exposure to ammonia.

  3. Fabrication slab waveguide based polymethyl methacrylate (PMMA) with spin coating method

    Science.gov (United States)

    Andriawan, Alan; Pramono, Yono Hadi; Masoed, Asnawi

    2016-11-01

    Fabrication and characterization slab waveguide based polymethyl methacrylate (PMMA) has been carried out. Slab waveguide fabrication done by the spin coating method. Slab waveguide fabrication process carried out by the rotational speed of 1000, 2000, and 3000 rpm respectively played for 10 seconds. Then the slab waveguides heated using a hot plate. Heating process starting from room temperature then increased 5°C to 70°C with a 5 minute warm-up time interval. From the results of characterization fabricated slab waveguides to determine the film thickness is made. Then made observations on the waveguide by passing the light beam He-Ne laser on the thin layer through a single mode optical fiber. From the results of characterization is known that the fabrication of a slab waveguide with a layer thickness of 166 μm. From this research it is known that polymethyl methacrylate (PMMA) can be used as a waveguide with a spin coating method.

  4. PMMA lens with high efficiency and reliability

    Science.gov (United States)

    Matsuzaki, Ichiro; Abe, Koji; Fujita, Katsuhiro

    2013-09-01

    Polymethyl Methacrylate (PMMA) Fresnel lenses are increasingly being used in concentrated photovoltaic (CPV) systems installed outdoors and, accordingly, emphasis is being placed on the durability of such lenses with regard to light transmittance when subject to ultraviolet (UV) light and dust exposure. Accelerated testing methods for evaluating durability under UV exposure were established, allowing development of a lens material with improved UV resistance. Simultaneously, through a proprietary molding method, a Fresnel lens that boasts favorable light concentration efficiency with little deformation even after prolonged outdoor use was developed. Moreover, the lens incorporates a new hard-coat finish that possesses sand durability and UV resistance comparable to that of tempered glass.

  5. Light scattering of PMMA latex particles in benzene: structural effects

    NARCIS (Netherlands)

    Nieuwenhuis, E.A.; Vrij, A.

    1979-01-01

    Intra- and interparticle structural effects were studied in polymethylmethacrylate (PMMA) latex dispersions in a nonpolar solvent with the technique of light scattering. The required transparency of the dispersions was attained by a close matching of the refractive index of PMMA and solvent, for whi

  6. Novel synthesis of ZnO/PMMA nanocomposites for photocatalytic applications

    Science.gov (United States)

    Di Mauro, Alessandro; Cantarella, Maria; Nicotra, Giuseppe; Pellegrino, Giovanna; Gulino, Antonino; Brundo, Maria Violetta; Privitera, Vittorio; Impellizzeri, Giuliana

    2017-01-01

    The incorporation of nanostructured photocatalysts in polymers is a strategic way to obtain novel water purification systems. This approach takes the advantages of: (1) the presence of nanostructured photocatalyst; (2) the flexibility of polymer; (3) the immobilization of photocatalyst, that avoids the recovery of the nanoparticles after the water treatment. Here we present ZnO-polymer nanocomposites with high photocatalytic performance and stability. Poly (methyl methacrylate) (PMMA) powders were coated with a thin layer of ZnO (80 nm thick) by atomic layer deposition at low temperature (80 °C). Then the method of sonication and solution casting was performed so to obtain the ZnO/PMMA nanocomposites. A complete morphological, structural, and chemical characterization was made by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses. The remarkable photocatalytic efficiency of the nanocomposites was demonstrated by the degradation of methylene blue (MB) dye and phenol in aqueous solution under UV light irradiation. The composites also resulted reusable and stable, since they maintained an unmodified photo-activity after several MB discoloration runs. Thus, these results demonstrate that the proposed ZnO/PMMA nanocomposite is a promising candidate for photocatalytic applications and, in particular, for novel water treatment. PMID:28098229

  7. Novel synthesis of ZnO/PMMA nanocomposites for photocatalytic applications

    Science.gov (United States)

    di Mauro, Alessandro; Cantarella, Maria; Nicotra, Giuseppe; Pellegrino, Giovanna; Gulino, Antonino; Brundo, Maria Violetta; Privitera, Vittorio; Impellizzeri, Giuliana

    2017-01-01

    The incorporation of nanostructured photocatalysts in polymers is a strategic way to obtain novel water purification systems. This approach takes the advantages of: (1) the presence of nanostructured photocatalyst; (2) the flexibility of polymer; (3) the immobilization of photocatalyst, that avoids the recovery of the nanoparticles after the water treatment. Here we present ZnO-polymer nanocomposites with high photocatalytic performance and stability. Poly (methyl methacrylate) (PMMA) powders were coated with a thin layer of ZnO (80 nm thick) by atomic layer deposition at low temperature (80 °C). Then the method of sonication and solution casting was performed so to obtain the ZnO/PMMA nanocomposites. A complete morphological, structural, and chemical characterization was made by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses. The remarkable photocatalytic efficiency of the nanocomposites was demonstrated by the degradation of methylene blue (MB) dye and phenol in aqueous solution under UV light irradiation. The composites also resulted reusable and stable, since they maintained an unmodified photo-activity after several MB discoloration runs. Thus, these results demonstrate that the proposed ZnO/PMMA nanocomposite is a promising candidate for photocatalytic applications and, in particular, for novel water treatment.

  8. Approach to osteomyelitis treatment with antibiotic loaded PMMA.

    Science.gov (United States)

    Wentao, Zhang; Lei, Guangyu; Liu, Yang; Wang, Wei; Song, Tao; Fan, Jinzhu

    2017-01-01

    To reduce the incidence of osteomyelitis infection, local antibiotic impregnated delivery systems are commonly used as a promising and effective approach to deliver high antibiotic concentrations at the infection site. The objective of this review was to provide a literature review regarding approach to osteomyelitis treatment with antibiotic loaded PMMA. Literature study regarding osteomyelitis treatment with antibiotic loaded carriers using key terms Antibiotic, osteomyelitis, biodegradable PMMA through published articles. Hands searching of bibliographies of identified articles were also undertaken. We concluded that Antibiotic-impregnated PMMA beads are useful options for the treatment of osteomyelitis for prolonged drug therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. PMMA-based capillary electrophoresis electrochemical detection microchip fabrication

    Science.gov (United States)

    Horng, Ray-Hua; Han, Pin; Chen, Hung-Yu; Lin, Kuan-Wen; Tsai, Tung-Mung; Zen, Jyh-Myng

    2005-01-01

    In this paper, a 50 µm (depth) × 50 µm (width) microfluidic channel is made on a poly(methyl methacrylate) (PMMA) substrate using thick photoresist. Openings were drilled for buffer reservoirs on an additional piece of PMMA. A final PMMA/patterned photoresist/PMMA sandwich configuration was completed using a bonding process. The thick photoresist was used as the adhesion layer and also as the microfluidic system. Using screen-printed technology for carbon and silver electrode fabrication, the microchip electrophoretic device functions were demonstrated. Successful detection of uric acid and L-ascorbic acid (the main components in human urine) validates the functionality of the proposed system. Successful ascorbic and uric acid separation in a sample from a urine donor who had consumed 500 mg of vitamins verified the proposed biochip.

  10. Optical properties of ZnO/PMMA nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kulyk, B., E-mail: bohdan_kulyk@yahoo.co [Department of Physics, Scientific and Educational Center ' Fractal' , Scientific-Technical and Educational Center of Low Temperature Studies, Ivan Franko National University of L' viv, 50 Dragomanova Str., L' viv (Ukraine); Kapustianyk, V.; Tsybulskyy, V. [Department of Physics, Scientific and Educational Center ' Fractal' , Scientific-Technical and Educational Center of Low Temperature Studies, Ivan Franko National University of L' viv, 50 Dragomanova Str., L' viv (Ukraine); Krupka, O. [Department of Chemistry, Kyiv Taras Shevchenko National University, 60 Volodymyrska Str., Kyiv (Ukraine); Sahraoui, B. [Institute of sciences and molecular technologies of Angers, MOLTECH Anjou - UMR CNRS 6200, Molecular interaction nonlinear optics and structuring MINOS, 2 bd Lavoisier, 49045 Angers Cedex 2 (France)

    2010-07-16

    The ZnO nanocrystals (ZnO NCs) with particle size, less than 100 nm, have been blended with polymethylmethacrylate (PMMA) by solution mixing to prepare PMMA/ZnO nanocomposite films. The structure of ZnO/PMMA nanocomposite films was characterized using X-ray diffractometry. The prepared nanocomposite films are highly transparent and a clear excitonic peak is observed in their absorption spectra. Measurements of temperature evolution of the photoluminescence (PL) spectra show intensive UV emission peak corresponding to the donor-bound excitons with binding energy of 51 meV and green emission band related to the intrinsic defects in ZnO. The temperature evolution of the emission peaks energy position, intensity and integral intensity in ZnO/PMMA nanocomposite films were examined.

  11. Tensile deformation mechanisms of ABS/PMMA/EMA blends

    Science.gov (United States)

    Wang, S. H.; Gao, J.; Lin, S. X.; Zhang, P.; Huang, J.; Xu, L. L.

    2014-08-01

    The tensile deformation mechanisms of acrylonitrile - butadiene - styrene (ABS) / polymethyl methacrylate (PMMA) blends toughened by ethylene methacrylate (EMA) copolymer was investigated by analysing the fracture morphology. ABS/PMMA was blended with EMA copolymer by melt mixing technique using co-rotating twin extruder. Tensile tests show that the elongation at break of ABS/PMMA blends can be efficiently improved with the increase in EMA content. Fracture morphology of ABS/PMMA/EMA blends reveals that the material yield induced by hollowing-out of EMA particles and its propagation into yield zone is the main toughening mechanism. Moreover, the appearance that EMA particles in the central area are given priority to hollowing-out may be related to the skin-core structure of the injection moulded parts caused by the different cooling rate between surface and inside in the process of injection moulding.

  12. Plasma Induced Grafting of PMMA onto Titanium Dioxide Powder

    Institute of Scientific and Technical Information of China (English)

    Zhong Shaofeng; Meng Yuedong; Ou Qiongrong; Xu Xu

    2005-01-01

    Grafting of polymer of methyl methacrylate (PMMA) onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrierdischarge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.

  13. Macrovoids formation and light scattering of PMMA

    Indian Academy of Sciences (India)

    Zhi Hong Chen; Z C Chang; C B Lin

    2007-08-01

    After desorption of PMMA with saturated methanol and ethanol and then desorption by distilled water, the macrovoids are formed because of the phase inversion. The macrovoids on the surface of the specimens are larger and more numerous than those in the bulk. The macrovoids are likely to be closed-type, if the hydrolysis temperature is lower. On the other hand, if the hydrolysis temperature is higher, the macrovoids are likely to be open-type. Due to the formation of macrovoids, smaller than visible wavelengths, the light will disperse, and therefore, reduces the transmittance of the specimens. The transmittance is decreased when the hydrolysis temperature and hydrolysis time are increased. Furthermore, it is much clearer when ethanol is used as solvent than methanol. The scattered intensity of the specimens after hydrolysis is inversely proportional to the visible wavelength with an exponent, , in the range 0.04–2.83 for methanol and 0.02–0.21 for ethanol.

  14. Injection molding of micro patterned PMMA plate

    Institute of Scientific and Technical Information of China (English)

    Yeong-Eun YOO; Tae-Hoon KIM; Tae-Jin JE; Doo-Sun CHOI; Chang-Wan KIM; Sun-Kyung KIM

    2011-01-01

    A plastic plate with surface micro features was injection molded to investigate the effect of pressure rise of melt on the replication of the micro structures. Prism pattern, which is used in many optical applications, was selected as a model pattern. The prism pattern is 50 μm in pitch and 108° in the vertical angle. The overall size of the plate was 335 mm×213 mm and the thickness of the plate varied linearly from 2.6 mm to 0.7 mm. The prism pattern was firstly machined on the nickel plated core block using micro diamond tool and this machined pattern core was installed in a mold for injection molding of prism patterned plate. Polymethyl methacrylate (PMMA) was used as a molding material. The pressure and temperature of the melt in the cavity were measured at different positions in the cavity and the replication of the pattern was also measured at the same positions. The results show that the pressure or temperature profile through the process depends on the shape and the size of the plate. The replication is affected by the temperature and pressure profiles at the early stage of filling, which is right after the melt reaches the position to be measured.

  15. Strengthening of Poly Methyl Methacrylate (PMMA) through Electron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Sung Ho; Lim, Hyung San; Ha, Jun Mok; Cho, Sung Oh [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Poly Methyl Methacrylate (PMMA) was previously known to show the deteriorating mechanical properties when irradiated with electrons. This is true for low electron irradiation does, but it was found, through experimentation, that at high irradiation dose, PMMA demonstrates improved mechanical properties. With enough electron irradiation dose, the scissions can form new links amongst one another to achieve stability that surpasses that of the PMMA in pre-irradiation treatment state. With higher irradiation dosage and beam strength, hardness of irradiated PMMA could be increased to a much greater extent. Electrons with 50keV of energy can only penetrate around 30 μm of PMMA, thus increasing the beam energy could potentially allow for hardening of not just the surface of the PMMA samples, but the whole samples themselves. Furthermore, Pencil Hardness Test is a method to roughly analyze a material's hardness and does not provide an accurate feedback on the mechanical properties of the material of interest. Hence, a more thorough and effective method of measuring data from the use of equipment such as IZOD Impact Tester, Strain-Stress Tester and Haze Meter will be utilized in the future.

  16. Fabrication of PMMA CE microchips by infrared-assisted polymerization.

    Science.gov (United States)

    Chen, Yun; Duan, Haotian; Zhang, Luyan; Chen, Gang

    2008-12-01

    In this report, a method based on the infrared-assisted polymerization of methyl methacrylate has been developed for the rapid fabrication of PMMA CE microchips. Methyl methacrylate containing AIBN was allowed to prepolymerize in a water bath to form a fast-curing molding solution that was subsequently sandwiched between a silicon template and a piece of 1 mm-thick PMMA plate. The images of microchannels on the silicon template were precisely replicated into the synthesized PMMA substrates during the infrared-assisted polymerization of the molding solution. The polymerization could be completed within 50 min at 50 degrees C. The obtained channel plate was subsequently bonded to a piece of PMMA cover sheet to form a microchip with the aid of heat and pressure. The new fabrication approach obviates the need for special equipment and significantly simplifies the process of fabricating PMMA microchips. The attractive performance of the obtained PMMA microchips has been demonstrated in connection with contactless conductivity detection for the separation and detection of ionic species.

  17. Preparation and characterization of transparent PMMA-cellulose-based nanocomposites.

    Science.gov (United States)

    Kiziltas, Esra Erbas; Kiziltas, Alper; Bollin, Shannon C; Gardner, Douglas J

    2015-01-01

    Nanocomposites of polymethylmethacrylate (PMMA) and cellulose were made by a solution casting method using acetone as the solvent. The nanofiber networks were prepared using three different types of cellulose nanofibers: (i) nanofibrillated cellulose (NFC), (ii) cellulose nanocrystals (CNC) and (iii) bacterial cellulose from nata de coca (NDC). The loading of cellulose nanofibrils in the PMMA varied between 0.25 and 0.5 wt%. The mechanical properties of the composites were evaluated using a dynamic mechanical thermal analyzer (DMTA). The flexural modulus of the nanocomposites reinforced with NDC at the 0.5 wt% loading level increased 23% compared to that of pure PMMA. The NFC composite also exhibited a slightly increased flexural strength around 60 MPa while PMMA had a flexural strength of 57 MPa. The addition of NDC increased the storage modulus (11%) compared to neat PMMA at room temperature while the storage modulus of PPMA/CNC nanocomposite containing 0.25 and 0.5 wt% cellulose increased about 46% and 260% to that of the pure PMMA at the glass transition temperature, respectively. Thermogravimetric analysis (TGA) indicated that there was no significant change in thermal stability of the composites. The UV-vis transmittance of the CNF nanocomposites decreased by 9% and 27% with the addition of 0.25 wt% CNC and NDC, respectively. This work is intended to spur research and development activity for application of CNF reinforced PMMA nanocomposites in applications such as: packaging, flexible screens, optically transparent films and light-weight transparent materials for ballistic protection.

  18. Silver release and antimicrobial properties of PMMA films doped with silver ions, nano-particles and complexes

    Energy Technology Data Exchange (ETDEWEB)

    Lyutakov, O., E-mail: lyutakoo@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, Prague (Czech Republic); Goncharova, I. [Department of Analytical Chemistry, Institute of Chemical Technology, Prague (Czech Republic); Rimpelova, S. [Department of Biochemistry and Microbiology, Institute of Chemical Technology, Prague (Czech Republic); Kolarova, K.; Svanda, J.; Svorcik, V. [Department of Solid State Engineering, Institute of Chemical Technology, Prague (Czech Republic)

    2015-04-01

    Materials prepared on the base of bioactive silver compounds have become more and more popular due to low microbial resistance to silver. In the present work, the efficiency of polymethylmethacrylate (PMMA) thin films doped with silver ions, nanoparticles and silver–imidazole polymer complex was studied by a combination of AAS, XPS and AFM techniques. The biological activities of the proposed materials were discussed in view of the rate of silver releasing from the polymer matrix. Concentrations of Ag active form were estimated by its ability to interact with L-cysteine using electronic circular dichroism spectroscopy. Rates of the released silver were compared with the biological activity in dependence on the form of embedded silver. Antimicrobial properties of doped polymer films were studied using two bacterial strains: Staphylococcus epidermidis and Escherichia coli. It was found that PMMA films doped with Ag{sup +} had greater activity than those doped with nanoparticles and silver–imidazole polymeric complexes. However, the antimicrobial efficiency of Ag{sup +} doped films was only short-term. Contrary, the antimicrobial activity of silver–imidazole/PMMA films increased in time of sample soaking. - Highlights: • PMMA thin films doped with silver ions, nanoparticles (AgNPs) and silver–imidazole helical complexes (AgIm) were studied. • Silver release from doped polymer films and its biological activity were estimated. • Antimicrobial properties of doped polymer films were also studied. • Ag ions doped films showed the strongest antimicrobial activity, which quickly disappeared. • AgIm and AgNPs doped films showed more stable antimicrobial properties. • AgIm complexes conserve their structure after addition into polymer and after leaching.

  19. EFFECT OF TACTICITY OF PMMA ON CRYSTALLINE STRUCTURE OF POLY VINYLIDENE FLUORIDE

    Institute of Scientific and Technical Information of China (English)

    CHEN Ye; YANG Decai

    1994-01-01

    Fourier transform infrared spectroscopy (FTIR) has been used to study the effect of tacticity of PMMA on β phase formation ofpoly vinylidene fluoride (PVF2) during quenching process. For pure PVF2, quenching at lower temperature results in the formation of β phase crystallites. The critical quenching temperature for β phase formation is about 30℃. Adding a given amount of PMMA (30%) results in the increase of the critical quenching temperature. For the blends of PVF2 with atactic PMMA (a-PMMA), the critical quenching temperature is about 45℃, whilefor the blends with syndiotactic PMMA (s-PMMA) , attains to about 70℃.

  20. Dielectric properties of PMMA-SiO2 hybrid films

    KAUST Repository

    Morales-Acosta, M. D.

    2010-03-01

    Organic-inorganic hybrid films were synthesized by a modified sol-gel process. PMMASiO2 films were prepared using methylmethacrylate (MMA), tetraethil-orthosilicate (TEOS) as silicon dioxide source, and 3-trimetoxi-silil-propil-methacrylate (TMSPM) as coupling agent. FTIR measurements were performed on the hybrid films to confirm the presence of PMMA-SiO2 bonding. In addition, metal-insulator-metal (MIM) devices were fabricated to study the dielectric constant of the films as function of frequency (1 KHz to 1 MHz). Electrical results show a weak trend of the dielectric constant of the hybrid films with MMA molar ratio. More importantly, the PMMA-SiO2 hybrid films showed a higher dielectric constant than SiO2 and PMMA layers, which is likely due to the presence of additional C-O-C bond. © (2010) Trans Tech Publications.

  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. Electrical and Mechanical Properties of PMMA/nano-ATO Composites

    Institute of Scientific and Technical Information of China (English)

    Wei Pan; Huiqin Zhang; Yan Chen

    2009-01-01

    Conducting nanocomposites of poly (methyl methacryiate) (PMMA) and antimony doped tin oxide (ATO)were prepared by solution blending. The influences of ATO content on the electrical conductivity, thermal stability, and mechanical properties of the nanocomposites were investigated. A homogeneous dispersion of silane coupling agent modified ATO was achieved in PMMA matrix as evidenced by scanning electron microscopy. The resultant PMMA/silane-ATO nanocomposites were electrically conductive with significant conductivity enhancement at 4 wt pct. It was found that the composition at 4 wt pct ATO gave the higher tensile strength. Furthermore, it gave the largest elongation at break value among all the compositions.Thermal stability of the nanocornposites was remarkably enhanced by the incorporation of silane-ATO.

  3. PMMA/MWCNT nanocomposite for proton radiation shielding applications

    Science.gov (United States)

    Li, Zhenhao; Chen, Siyuan; Nambiar, Shruti; Sun, Yonghai; Zhang, Mingyu; Zheng, Wanping; Yeow, John T. W.

    2016-06-01

    Radiation shielding in space missions is critical in order to protect astronauts, spacecraft and payloads from radiation damage. Low atomic-number materials are efficient in shielding particle-radiation, but they have relatively weak material properties compared to alloys that are widely used in space applications as structural materials. However, the issues related to weight and the secondary radiation generation make alloys not suitable for space radiation shielding. Polymers, on the other hand, can be filled with different filler materials for reinforcement of material properties, while at the same time provide sufficient radiation shielding function with lower weight and less secondary radiation generation. In this study, poly(methyl-methacrylate)/multi-walled carbon nanotube (PMMA/MWCNT) nanocomposite was fabricated. The role of MWCNTs embedded in PMMA matrix, in terms of radiation shielding effectiveness, was experimentally evaluated by comparing the proton transmission properties and secondary neutron generation of the PMMA/MWCNT nanocomposite with pure PMMA and aluminum. The results showed that the addition of MWCNTs in PMMA matrix can further reduce the secondary neutron generation of the pure polymer, while no obvious change was found in the proton transmission property. On the other hand, both the pure PMMA and the nanocomposite were 18%-19% lighter in weight than aluminum for stopping the protons with the same energy and generated up to 5% fewer secondary neutrons. Furthermore, the use of MWCNTs showed enhanced thermal stability over the pure polymer, and thus the overall reinforcement effects make MWCNT an effective filler material for applications in the space industry.

  4. PMMA/MWCNT nanocomposite for proton radiation shielding applications.

    Science.gov (United States)

    Li, Zhenhao; Chen, Siyuan; Nambiar, Shruti; Sun, Yonghai; Zhang, Mingyu; Zheng, Wanping; Yeow, John T W

    2016-06-10

    Radiation shielding in space missions is critical in order to protect astronauts, spacecraft and payloads from radiation damage. Low atomic-number materials are efficient in shielding particle-radiation, but they have relatively weak material properties compared to alloys that are widely used in space applications as structural materials. However, the issues related to weight and the secondary radiation generation make alloys not suitable for space radiation shielding. Polymers, on the other hand, can be filled with different filler materials for reinforcement of material properties, while at the same time provide sufficient radiation shielding function with lower weight and less secondary radiation generation. In this study, poly(methyl-methacrylate)/multi-walled carbon nanotube (PMMA/MWCNT) nanocomposite was fabricated. The role of MWCNTs embedded in PMMA matrix, in terms of radiation shielding effectiveness, was experimentally evaluated by comparing the proton transmission properties and secondary neutron generation of the PMMA/MWCNT nanocomposite with pure PMMA and aluminum. The results showed that the addition of MWCNTs in PMMA matrix can further reduce the secondary neutron generation of the pure polymer, while no obvious change was found in the proton transmission property. On the other hand, both the pure PMMA and the nanocomposite were 18%-19% lighter in weight than aluminum for stopping the protons with the same energy and generated up to 5% fewer secondary neutrons. Furthermore, the use of MWCNTs showed enhanced thermal stability over the pure polymer, and thus the overall reinforcement effects make MWCNT an effective filler material for applications in the space industry.

  5. Blue-shifted photoluminescence of Alq3 dispersed in PMMA

    Indian Academy of Sciences (India)

    J G Mahakhode; S J Dhoble; C P Joshi; S V Moharil

    2011-12-01

    Alq3 is known to emit bright green light under UV excitation. Blue shift of the emission was reported in recent literature. This was ascribed to the presence of various isomers/crystallographic modifications obtained through train sublimation. Here a blue shift was reported for Alq3 dispersed in PMMA. No isomers/phases, which were reponsible for blue-shift, separated and yet the emission maxima shift to shorter wavelengths as the concentration of Alq3 in PMMA decreases. The results were interpreted on the basis of cross relaxation between interacting Alq3 molecules.

  6. Multi-wavelength optical storage of diarylethene PMMA film

    Science.gov (United States)

    Guo, Haobo; Zhang, Fushi; Wu, Guo-shi; Sun, Fan; Pu, Shouzhi; Mai, Xuesong; Qi, Guosheng

    2003-05-01

    Current commercial optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene derivatives were dispersed into PMMA solution, and spin-coated on a glass substrate with Al reflective layer as the recording layer. Two laser beams of 532 and 650 nm were used in recording and readout simultaneously, and signals with high S/ N ratio were detected. Multi-wavelength optical storage was realized with the diarylethene PMMA film.

  7. Fabrication of Embedded Microvalve on PMMA Microfluidic Devices through Surface Functionalization

    CERN Document Server

    Toh, A G G; Ng, S H

    2008-01-01

    The integration of a PDMS membrane within orthogonally placed PMMA microfluidic channels enables the pneumatic actuation of valves within bonded PMMA-PDMS-PMMA multilayer devices. Here, surface functionalization of PMMA substrates via acid catalyzed hydrolysis and air plasma corona treatment were investigated as possible techniques to permanently bond PMMA microfluidic channels to PDMS surfaces. FTIR and water contact angle analysis of functionalized PMMA substrates showed that air plasma corona treatment was most effective in inducing PMMA hydrophilicity. Subsequent fluidic tests showed that air plasma modified and bonded PMMA multilayer devices could withstand fluid pressure at an operational flow rate of 9 mircoliters/min. The pneumatic actuation of the embedded PDMS membrane was observed through optical microscopy and an electrical resistance based technique. PDMS membrane actuation occurred at pneumatic pressures of as low as 10kPa and complete valving occurred at 14kPa for 100 micrometers x 100 micromet...

  8. Influence of MeV H+ ion beam flux on cross-linking and blister formation in PMMA resist

    Directory of Open Access Journals (Sweden)

    Somrit Unai

    2012-02-01

    Full Text Available In soft lithography, a pattern is produced in poly(dimethylsiloxane (PDMS elastomer by casting from a master mould. The mould can be made of poly(methylmethacrylate (PMMA resist by utilising either its positive or negative tone induced by an ion beam. Here we have investigated the irradiation conditions for achieving complete cross-linking and absence of blister formation in PMMA so that its negative characteristic can be used in making master moulds. PMMA thin films approximately 9 µm thick on Si were deposited by spin coating. The 2-MeV H+ ion beam was generated using a 1.7-MV tandem Tandetron accelerator. The beam was collimated to a 500×500 µm2 cross section using programmable proximity aperture lithography system with a real-time ion beam monitoring system and a high precision current integrator. The irradiated areas were investigated by a standard scanning electron microscope and a profilometer. It was found that both the ion beam flux and the stopping power of the ions in the polymer have a critical influence on the blister formation.

  9. PMMA-hydroxyapatite composite material retards fatigue failure of augmented bone compared to augmentation with plain PMMA: in vivo study using a sheep model.

    Science.gov (United States)

    Arabmotlagh, Mohammad; Bachmaier, Samuel; Geiger, Florian; Rauschmann, Michael

    2014-11-01

    Polymethylmethacrylate (PMMA) is the most commonly used void filler for augmentation of osteoporotic vertebral fracture, but the differing mechanical features of PMMA and osteoporotic bone result in overload and failure of adjacent bone. The aim of this study was to compare fatigue failure of bone after augmentation with PMMA-nanocrystalline hydroxyapatite (HA) composite material or with plain PMMA in a sheep model. After characterization of the mechanical properties of a composite material consisting of PMMA and defined amounts (10, 20, and 30% volume fraction) of HA, the composite material with 30% volume fraction HA was implanted in one distal femur of sheep; plain PMMA was implanted in the other femur. Native non-augmented bone served as control. Three and 6 months after implantation, the augmented bone samples were exposed to cyclic loading and the evolution of damage was investigated. The fatigue life was highest for the ovine native bone and lowest for bone-PMMA specimens. Bone-composite specimens showed significantly higher fatigue life than the respective bone-PMMA specimens in both 3- and 6-month follow-up groups. These results suggest that modification of mechanical properties of PMMA by addition of HA to approximate those of cancellous bone retards fatigue failure of the surrounding bone compared to augmented bone with plain PMMA.

  10. Highly conductive poly(methyl methacrylate) (PMMA)-reduced graphene oxide composite prepared by self-assembly of PMMA latex and graphene oxide through electrostatic interaction.

    Science.gov (United States)

    Pham, Viet Hung; Dang, Thanh Truong; Hur, Seung Hyun; Kim, Eui Jung; Chung, Jin Suk

    2012-05-01

    We report a simple, environmentally friendly approach for preparing highly conductive poly(methyl methacrylate)-reduced graphene oxide (PMMA-RGO) composites by self-assembly of positively charged PMMA latex particles and negatively charged graphene oxide sheets through electrostatic interactions, followed by hydrazine reduction. The PMMA latex was prepared by surfactant-free emulsion polymerization using a cationic free radical initiator, which created the positive charges on the surface of the PMMA particle. By mixing PMMA latex with a graphene oxide dispersion, positively charged PMMA particles easily assembled with negatively charged graphene oxide sheets through electrostatic interaction. The obtained PMMA-RGO exhibited excellent electrical properties with a percolation threshold as low as 0.16 vol % and an electrical conductivity of 64 S/m at only 2.7 vol %. Moreover, the thermomechanical properties of PMMA-RGO were also significantly improved. The storage modulus of PMMA-RGO increased by about 30% at 4.0 wt % RGO at room temperature while the glass transition temperature of PMMA-RGO increased 15 °C at only 0.5 wt % RGO.

  11. Effects of the embedding kinetics on the surface nano-morphology of nano-grained Au and Ag films on PS and PMMA layers annealed above the glass transition temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ruffino, F.; Grimaldi, M.G. [Dipartimento di Fisica ed Astronomia, Universita di Catania, Catania (Italy); MATIS IMM-CNR, Catania (Italy); Torrisi, V.; Marletta, G. [University of Catania, CSGI, Laboratory for Molecular Surface and Nanotechnology (LAMSUN), Department of Chemical Sciences, Catania (Italy)

    2012-06-15

    The morphology evolution of nano-grained Ag and Au films deposited on polystyrene (PS) and poly(methyl methacrylate) (PMMA) polymeric layers were studied, using the atomic force microscopy technique, when annealed above the polymers glass transition temperature. The main effects on the morphology changes were identified with those concerning the embedding kinetics of the Ag and Au nanoparticles in the PS or PMMA layers. The embedding process of the nanoparticles follows as a consequence of the long-range mobility of the polymeric chains above the glass transition temperature. In particular, the dependence of the nanoparticles mean height and surface density on the annealing time at various temperatures was quantified. The analyses of these behaviors allowed us: (1) to distinguish the overall embedding process in a first stage in which a thin wetting layer of the polymer coats the nanoparticles followed by a true embedding process of the nanoparticles into the polymer layer; (2) to evaluate the characteristic coating time for the Ag and Au nanoparticles in the PS and PMMA in the first stage; (3) to evaluate the characteristic embedding velocity for the Ag and Au nanoparticles in the PS and PMMA in the second stage; (4) to derive the activation energies for the embedding process of the Ag and Au nanoparticles in PS and PMMA; (5) to identify the embedding statistics of the Ag and Au nanoparticles in PS and PMMA with a ''failure'' Weibull statistics. (orig.)

  12. Soft X-ray radiation-damage studies in PMMA using a cryo-STXM.

    Science.gov (United States)

    Beetz, Tobias; Jacobsen, Chris

    2003-05-01

    Radiation damage sets a fundamental limit for studies with ionizing radiation; cryo-methods are known to ease these limits. Here, measurements on mass loss and the decrease in the C=O bond density as measured by oxygen-edge XANES (NEXAFS) spectroscopy in thin films of poly(methylmethacrylate) (PMMA), studied in a vacuum, are reported. While cryo-methods allow more than 95% of the mass to remain at doses up to 10(7) Gy, there is little difference in C=O bond density versus dose between 298 K and 113 K sample temperatures. At both temperatures the critical dose for bond breaking is approximately 15 x 10(6) Gy.

  13. Preparation of PMMA Foam by Supercritical CO2 with Ethanol

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Supercritical CO2 with ethanol as blowing agent foamed poly(methylmethacrylate) (PMMA) fiber at 308.15K and in the pressure range from 12-15MPa. The foam structure was detected using scanning electron microscope. It was found that the concentration of ethanol in the fluid is a major parameter to affect the foam structure.

  14. Capillary wrinkling of thin bilayer polymeric sheets

    Science.gov (United States)

    Chang, Jooyoung; Menon, Narayanan; Russell, Thomas

    We have investigated capillary force induced wrinkling on a floated polymeric bilayer thin sheet. The origin of the wrinkle pattern is compressional hoop stress caused by the capillary force of a water droplet placed on the floated polymeric thin sheet afore investigated. Herein, we study the effect of the differences of surface energy arising from the hydrophobicity of Polystyrene (PS Mw: 97 K, Contact Angle: 88 º) and the hydrophilicity of Poly(methylmethacrylate) (PMMA Mw: 99K, Contact Angle: 68 º) on two sides of a bilayer film. We measure the number and the length of the wrinkles by broadly varying the range of thicknesses of top (9 nm to 550 nm) and bottom layer (25 nm to 330 nm). At the same, there is only a small contrast in mechanical properties of the two layers (PS E = 3.4 GPa, and PMMA E = 3 GPa). The number of the wrinkles is not strongly affected by the composition (PS(Top)/PMMA(Bottom) or PMMA(Top)/PS(Bottom)) and the thickness of each and overall bilayer system. However, the length of the wrinkle is governed by the contact angle of the drop on the top layer of bilayer system. We also compare this to the wrinkle pattern obtained in monolayer systems over a wide range of thickness from PS and PMMA (7 nm to 1 μm). W.M. Keck Foundation.

  15. Mechanical and thermal properties of denture PMMA reinforced with silanized aluminum borate whiskers.

    Science.gov (United States)

    Zhang, Xinjing; Zhang, Xiuyin; Zhu, Bangshang; Lin, Kaili; Chang, Jiang

    2012-01-01

    The aim of this study was to investigate the mechanical and thermal properties of denture polymethyl methacrylate (PMMA) reinforced with aluminum borate whiskers (ABWs). To improve bonding between ABWs and PMMA matrix, the surface of ABWs was modified with a silane coupling agent. Varied contents of silanized ABWs -ranging between 1 and 20 wt%- were mixed into the PMMA resin matrix to prepare ABW/PMMA composites, which were subjected to three-point bending test, Vickers hardness test, and thermal analysis. Silanized ABWs improved the flexural strength, surface hardness, and thermal stability of PMMA. Optimal amount of ABWs in the PMMA matrix was 5 wt%, which provided the ABW/PMMA with maximum reinforcement.

  16. A Study on the Effect of Nano Alumina Particles on Fracture Behavior of PMMA

    Directory of Open Access Journals (Sweden)

    Arezou Sezavar

    2015-04-01

    Full Text Available In the current research, the role of nano-sized alumina on deformation and fracture mechanism of Poly Methyl Methacrylate (PMMA was investigated. For this purpose, PMMA matrix nanocomposite reinforced with different wt% of alumina (i.e., 5, 10 and 15 were fabricated using the compression molding technique. Tensile properties of produced nanocomposites were studied using Zwick Z250 apparatus at cross head speed of about 5 mm/min. In order to specify the role of alumina nanoparticles on deformation and fracture mechanism of PMMA, microscopic evaluation was performed using scanning electron microscope (SEM. The achieved results prove that tensile properties of PMMA depend on alumina wt%. For example, addition of 15 wt% alumina to PMMA causes an increase of about 25% modulus of elasticity. Micrographs taken from the fracture surface of PMMA and its nanocomposites show deformation and fracture mechanism of PMMA changes as alumina is added to it.

  17. Welding of PMMA by a femtosecond fiber laser.

    Science.gov (United States)

    Volpe, Annalisa; Di Niso, Francesca; Gaudiuso, Caterina; De Rosa, Andrea; Vázquez, Rebeca Martínez; Ancona, Antonio; Lugarà, Pietro Mario; Osellame, Roberto

    2015-02-23

    Developing versatile joining techniques to weld transparent materials on a micrometer scale is of great importance in a growing number of applications, especially for the fabrication and assembly of biomedical devices. In this paper, we report on fs-laser microwelding of two transparent layers of polymethyl methacrylate (PMMA) based on nonlinear absorption and localized heat accumulation at high repetition rates. A fiber CPA laser system was used delivering 650-fs pulses at 1030 nm with repetition rates in the MHz regime. The laser-induced modifications produced by the focused beam into the bulk PMMA were firstly investigated, trying to find a suitable set of process parameters generating continuous and localized melting. Results have been evaluated based on existing heat accumulation models. Then, we have successfully laser welded two 1-mm-thick PMMA layers in a lap-joint configuration. Sealing of the sample was demonstrated through static and dynamic leakage tests. This fs-laser micro-welding process does not need any pre-processing of the samples or any intermediate absorbing layer. Furthermore, it offers several advantages compared to other joining techniques, because it prevents contamination and thermal distortion of the samples, thus being extremely interesting for application in direct laser fabrication of microfluidic devices.

  18. Physical Properties of Polyamide-12 versus PMMA Denture Base Material

    Directory of Open Access Journals (Sweden)

    Mieszko Wieckiewicz

    2014-01-01

    Full Text Available Objectives. Polyamide-12 (PA is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity. Methods. PA specimens (Valplast of 40×10×2 mm and equally measuring PMMA specimens (Palapress as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n=10 were measured using the CIE L*a*b* color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles,  n=15 was measured by three-point bending testing. Mean surface roughness (Ra was determined after storage in the liquids mentioned above and thermocycling (n=10. Results. Tukey’s HSD test (P0.81. Dry specimens showed significantly decreased elasticity (P<0.001. Mean surface roughness (PA 0.20 μm, PMMA 0.28 μm did not change significantly after thermocycling or storage (Mann-Whitney U-test,  0.16PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.

  19. Preparation and characterization of PVC/PMMA blend polymer electrolytes complexed with LiN(C2F5SO22

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2004-03-01

    Full Text Available Thin films of polymer blend electrolytes comprising Poly(vinyl chloride (PVC and Poly(methyl methacrylate(PMMA and plasticized with a combination of ethylene carbonate (EC and propylene carbonate (PC for different lithium imide salt, LiN(C2F5SO32 , concentrations were prepared using the solution casting technique. The films were subjected to a. c. impedance measurements as a function of temperature ranging from -30 °C to 70 °C. The variation of ionic conductivity as a function of temperature and PVC content in the blend was analysed. The role of PMMA in the phenomena occurring at the interface between the plasticized polymer electrolyte and lithium electrode was also studied. The cast films were also subjected to TG/DTA and FT-IR studies which are discussed.

  20. 3D-printed PMMA Preform for Hollow-core POF Drawing

    DEFF Research Database (Denmark)

    Zubel, M. G.; Fasano, Andrea; Woyessa, Getinet

    2016-01-01

    In this paper we report the first, to our knowledge, 3D-printed hollow-core poly(methyl methacrylate) (PMMA) preform for polymer optical fibre drawing. It was printed of commercial PMMA by means of fused deposition modelling technique. The preform was drawn to cane, proving good enough quality...... of drawing process and the PMMA molecular weight to be appropriate for drawing. This ascertains that the manufacturing process provides preforms suitable for hollow-core fibre drawing. The paper focuses on maximisation of transparency of PMMA 3D printouts by optimising printing process parameters: nozzle...

  1. Study of the interconversion between viscoelastic behaviour functions of PMMA

    Science.gov (United States)

    Fernández, P.; Rodríguez, D.; Lamela, M. J.; Fernández-Canteli, A.

    2011-05-01

    The use of polymers and polymer-based composites in mechanical, civil and electronic engineering has been growing owing to advances in the technology of materials. The different applications and working conditions of these materials require knowledge about their viscoelastic material functions: relaxation modulus, compliance, complex modulus, etc. Interconversion between these functions may be required for different reasons such as the impossibility of direct experimentation under certain excitation conditions. In this work, a DMA is used to calculate the experimental viscoelastic functions of a linear viscoelastic material (PMMA). The same functions are estimated by interconversion methods and compared with experimental ones. The results show that the interconversion functions fit properly the experimental functions.

  2. Microindentation of Polymethyl Methacrylate (PMMA Based Bone Cement

    Directory of Open Access Journals (Sweden)

    F. Zivic

    2011-12-01

    Full Text Available Characterization of polymethyl methacrylate (PMMA based bone cement subjected to cyclical loading using microindentation technique is presented in this paper. Indentation technique represents flexible mechanical testing due to its simplicity, minimal specimen preparation and short time needed for tests. The mechanical response of bone cement samples was studied. Realised microindentation enabled determination of the indentation testing hardness HIT and indentation modulus EIT of the observed bone cement. Analysis of optical photographs of the imprints showed that this technique can be effectively used for characterization of bone cements.

  3. Proton beam micromachining on PMMA, Foturan and CR-39 materials

    CERN Document Server

    Rajta, I; Kiss, A Z; Gomez-Morilla, I; Abraham, M H

    2003-01-01

    Proton Beam Micromachining was demonstrated at the Institute of Nuclear Research of the Hungarian Academy of Sciences using three different types of resists: PMMA, Foturan and CR-39 type Solid State Nuclear Track Detector material. Irradiations have been performed on the nuclear microprobe facility at ATOMKI. The beam scanning was done using a National Instruments (NI) card (model 6711), and the new C++ version of the program IonScan, developed specifically for PBM applications called IonScan 2.0. (R.P.)

  4. Effects of Incorporating Carboxymethyl Chitosan into PMMA Bone Cement Containing Methotrexate.

    Directory of Open Access Journals (Sweden)

    Bo-Ming Liu

    Full Text Available Treatment of bone metastases usually includes surgical resection with local filling of methotrexate (MTX in polymethyl methacrylate (PMMA cement. We investigated whether incorporating carboxymethyl chitosan (CMCS in MTX-PMMA cement might overcome disadvantages associated with MTX. To determine the optimal CMCS+MTX concentration to suppress the viability of cancer cells, an integrated microfluidic chip culturing highly metastatic lung cancer cells (H460 was employed. The mechanical properties, microstructure, and MTX release of (CMCS+MTX-PMMA cement were evaluated respectively by universal mechanical testing machine, scanning electron microscopy (SEM, and incubation in simulated body fluid with subsequent HPLC-MS. Implants of MTX-PMMA and (CMCS+MTX-PMMA cement were evaluated in vivo in guinea pig femurs over time using spiral computed tomography with three-dimensional image reconstruction, and SEM at 6 months. Viability of H460 cells was significantly lowest after treatment with 57 μg/mL CMCS + 21 μg/mL MTX, which was thus used in subsequent experiments. Incorporation of 1.6% (w/w CMCS to MTX-PMMA significantly increased the bending modulus, bending strength, and compressive strength by 5, 2.8, and 5.2%, respectively, confirmed by improved microstructural homogeneity. Incorporation of CMCS delayed the time-to-plateau of MTX release by 2 days, but increased the fraction released at the plateau from 3.24% (MTX-PMMA to 5.34%. Relative to the controls, the (CMCS+MTX-PMMA implants integrated better with the host bone. SEM revealed pores in the cement of the (CMCS+MTX-PMMA implants that were not obvious in the controls. In conclusion, incorporation of CMCS in MTX-PMMA appears a feasible and effective modification for improving the anti-tumor properties of MTX-PMMA cement.

  5. Effect of Air Plasma Processing on the Adsorption Behaviour of Bovine Serum Albumin on Spin-Coated PMMA Surfaces

    Institute of Scientific and Technical Information of China (English)

    Chaozong Liu; Brian J.Meenan

    2008-01-01

    This paper reports the adsorption of Bovine Serum Albumin (BSA) onto Dielectric Barrier Discharge (DBD) processed Poly(methyl methacrylate) (PMMA) surfaces by a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) technique. The purpose is to study the influence of DBD processing on the nature and scale of BSA adsorption on PMMA surface in vitro. It was observed that DBD processing improves the surface wettability of PMMA film, a fact attributable to the changes in surface chemistry and topography. Exposure of the PMMA to Phosphate Buffed Saline (PBS) solution in the QCM-D system resulted in surface adsorption which reaches an equilibrium after about 30 minutes for pristine PMMA, and 90 minutes for processed PMMA surface. Subsequent injection of BSA in PBS indicated that the protein is immediately adsorbed onto the PMMA surface. It was revealed that adsorption behaviour of BSA on pristine PMMA differs from that on processed PMMA surface. A slower adsorption kinetics was observed for pristine PMMA surface, whilst a quick adsorption kinetics for processed PMMA. Moreover, the dissipation shift of protein adsorption suggested that BSA forms a more rigid structure on pristine PMMA surface that on processed surface. These data suggest that changes in wettability and attendant chemical properties and surface texture of the PMMA surface may play a significant role in BSA adsorption process.

  6. Microwave Induced Ethanol Bath Bonding for PMMA Microfluidic Device

    Institute of Scientific and Technical Information of China (English)

    Cuicui Zhuang

    2016-01-01

    High bonding strength, low deformation and convenient procedure are all very important aspects in the microfluidic device fabrication process. In this paper, an improved microwave induced bonding technology is proposed to fabricate microfluidic device based on methyl methacrylate (PMMA). This method employs pure ethanol as the bonding assisted solvent. The ethanol not only acts as the microwave absorbing material, but also works as the organic solvent in bath. The presented research work has shown that the bonding process can be completed in less than 45 s. Furthermore, the convenient bonding only applies microwave oven, beakers and binder clips. Then, we discuss effects of microwave power, bonding time on bonding strength and deformation of microstructures on PMMA microfluidic device. Finally, a 4 layers micro⁃mixer has been fabricated using the proposed bonding technique which includes 15 trapezoid micro⁃channels, 9 T⁃type mix units and an X⁃type mix unit. Experimental results show that the proposed bonding method have some advantages compared with several traditional bonding technologies, such as hot pressing bonding, ultrasonic bonding and solvent assisted bonding methods in respect of bonding strength, deformation and bonding process. The presented work would be helpful for low coat mass production of multilayer polymer microfluidic devices in lab.

  7. Low-modulus PMMA bone cement modified with castor oil.

    Science.gov (United States)

    López, Alejandro; Hoess, Andreas; Thersleff, Thomas; Ott, Marjam; Engqvist, Håkan; Persson, Cecilia

    2011-01-01

    Some of the current clinical and biomechanical data suggest that vertebroplasty causes the development of adjacent vertebral fractures shortly after augmentation. These findings have been attributed to high injection volumes as well as high Young's moduli of PMMA bone cements compared to that of the osteoporotic cancellous bone. The aim of this study was to evaluate the use of castor oil as a plasticizer for PMMA bone cements. The Young's modulus, yield strength, maximum polymerization temperature, doughing time, setting time and the complex viscosity curves during curing, were determined. The cytotoxicity of the materials extracts was assessed on cells of an osteoblast-like cell line. The addition of up to 12 wt% castor oil decreased yield strength from 88 to 15 MPa, Young's modulus from 1500 to 446 MPa and maximum polymerization temperature from 41.3 to 25.6°C, without affecting the setting time. However, castor oil seemed to interfere with the polymerization reaction, giving a negative effect on cell viability in a worst-case scenario.

  8. Surface modification on PMMA : PVDF polyblend: hardening under chemical environment

    Indian Academy of Sciences (India)

    R Bajpai; V Mishra; Pragyesh Agrawal; S C Datt

    2002-02-01

    The influence of chemical environment on polymers include the surface alteration as well as other deep modifications in surface layers. The surface hardening, as an effect of organic liquids on poly(methyl methacrylate): poly(vinylidene fluoride) (PMMA: PVDF), which is one of the few known miscible blends, has been detected using microhardness testing. Organic liquids like acetone, toluene, xylene and benzene were introduced on the surface of blend specimens for different durations. Vickers microhardness (v) was measured for treated and untreated specimens. The study reveals both hardening and plasticization of specimens at different exposure times. The degree of surface hardening is maximum under acetone treatment. All the specimens exhibit surface hardening at an exposure time of 1 h with all the four liquids. This feature is prominent with longer exposures for specimens with increasing content of PVDF. However, the degree of hardening decreases with the time of exposure in the respective environments. In general, acetone and toluene impart surface hardening, whereas, xylene and benzene soften the specimen. PMMA: PVDF (83 : 17) blend exhibits surface hardening under all the four treatments when compared with the respective untreated specimens.

  9. Electrical Properties of Electrospun Fibers of PANI-PMMA Composites

    Directory of Open Access Journals (Sweden)

    Jagadeesh Babu Veluru

    2007-07-01

    Full Text Available Electrospinning is one of the simplest techniques for obtaining polymer nano fibers. Nanofibers have large surface area to volume ratio and hence have excellent application potential in sensors, filter design etc. Polyaniline (PANI is the well-known and widely studied conducting polymer, which however, is insoluble in many common organic solvents and hence difficult to process. PANI in its base form is non conductive but it can be made conducting by protonating with an acids such as hydrochloric acid (HCl or camphor sulphonic acid (CSA. However, it is difficult to electrospin PANI by itself since we need preferably the polymer in solution form. In this study we have formed nanofibers of PANI (CSA dispersed in Poly Methyl Methacrylate (PMMA solution in chloroform. The morphology of the electrospun conducting PMMA-PANI composite fibers is studied using Scanning Electron Microscopy (SEM and Atomic Force Microscopy (AFM. The DC and AC conductivities of these fibers are measured and the results are discussed.

  10. Viscoelastic-Viscoplastic Modelling of the Scratch Response of PMMA

    Directory of Open Access Journals (Sweden)

    G. Kermouche

    2013-01-01

    Full Text Available This paper aims at understanding how to model the time-dependent behavior of PMMA during a scratch loading at a constant speed and at middle strain levels. A brief experimental study is first presented, consisting of the analysis of microscratches carried out at various scratching velocities and normal loads. The loading conditions have been chosen in such a way that neither (viscoelasticity nor (viscoplasticity of the PMMA may be neglected a priori. The main analyzed parameter is the tip penetration depth measured during the steady state. Then, a finite element model is used to investigate the potential of classical elastic-viscoplastic constitutive models to reproduce these experimental results. It is mainly shown that these models lead to unsatisfying results. More specifically, it is pointed out here that the time-independent Young modulus used in such models is not suitable. To take into account this feature, a viscoelastic-viscoplastic model based on the connection in series of a viscoelastic part with a viscoplastic part is proposed. It is shown that it leads to more acceptable results, which points out the importance of viscoelasticity in the scratch behavior of solid polymers.

  11. Modeling of secondary radiation damage in LIGA PMMA resist exposure

    Science.gov (United States)

    Ting, Aili

    2003-01-01

    Secondary radiation during LIGA PMMA resist exposure adversely affects feature definition, sidewall taper and overall sidewall offset. Additionally, it can degrade the resist adjacent to the substrate, leading to the loss of free-standing features through undercutting during resist development or through mechanical failure of the degraded material. The source of this radiation includes photoelectrons, Auger electrons, fluorescence photons, etc. Sandia"s Integrated Tiger Series (ITS), a coupled electron/photon Monte Carlo transport code, was used to compute dose profiles within 1 to 2 microns of the absorber edge and near the interface of the resist with a metallized substrate. The difficulty of sub-micron resolution requirement was overcome by solving a few local problems having carefully designed micron-scale geometries. The results indicate a 2-μm dose transition region near the absorber edge resulting from PMMA"s photoelectrons. This region leads to sidewall offset and to tapered sidewalls following resist development. The results also show a dose boundary layer of around 1 μm near the substrate interface due to electrons emitted from the substrate metallization layer. The maximum dose at the resist bottom under the absorber can be very high and can lead to feature loss during development. This model was also used to investigate those resist doses resulting from multi-layer substrate.

  12. Integration of a Graphite/PMMA CompositeElectrode into a Poly(methyl methacrylate) (PMMA) Substrate for Electrochemical Detection in Microchips

    Science.gov (United States)

    Regel, Anne; Lunte, Susan

    2013-01-01

    Traditional fabrication methods for polymer microchips, the bonding of two substrates together to form the microchip, can make the integration of carbon electrodes difficult. We have developed a simple and inexpensive method to integrate graphite/PMMA composite electrodes (GPCEs) into a PMMA substrate. These substrates can be bonded to other PMMA layers using a solvent-assisted thermal bonding method. The optimal composition of the GPCEs for electrochemical detection was determined using cyclic voltammetry with dopamine as a test analyte. Using the optimized GPCEs in an all-PMMA flow cell with flow injection analysis, it was possible to detect 50 nM dopamine under the best conditions. These electrodes were also evaluated for the detection of dopamine and catechol following separation by microchip electrophoresis (ME). PMID:23670816

  13. Direct fabrication of hybrid nanofibres composed of SiO2-PMMA nanospheres via electrospinning.

    Science.gov (United States)

    Zhang, Ran; Shang, Tinghua; Yang, Guang; Jia, Xiaolong; Cai, Qing; Yang, Xiaoping

    2016-08-01

    The direct fabrication of hybrid nanofibres composed of poly(methyl methacrylate)-grafted SiO2 (SiO2-PMMA) nanospheres via electrospinning was investigated in detail. SiO2-PMMA nanospheres were successfully prepared, with the SiO2 nanospheres synthesized via the Stober method, followed by in situ surface-initiated atom transfer radical polymerization of methyl methacrylate (MMA). Electrospinning was carried out with N,N-dimethylformamide (DMF) as the solvent to disperse SiO2-PMMA nanospheres. The size of the SiO2 core, the molecular weight of the PMMA shell and the concentration of the SiO2-PMMA/DMF solution all had substantial effects on the morphology and structure of electrospun nanofibres composed of SiO2-PMMA nanospheres. When these determining factors were well-tailored, it was found that one-dimensional necklace-like nanofibres were obtained, with SiO2-PMMA nanospheres aligned one by one along the fibre. The successful fabrication of nanofibres by directly electrospinning the SiO2-PMMA/DMF solution verified that polymer-grafted particles possess polymer-like characteristics, which endowed them with the ability to be processed into desirable shapes and structures.

  14. Comparison of Optical Performance in Eyes Implanted With Aspheric Foldable, Spherical Foldable, and Rigid PMMA IOLs

    NARCIS (Netherlands)

    van Gaalen, Kim W.; Jansonius, Nomdo M.; Koopmans, Steven A.; Kooijman, Aart C.

    2011-01-01

    PURPOSE: To compare the optical performance of rigid spherical polymethylmethacrylate (PMMA), foldable spherical, and foldable aspheric intraocular lenses (IOLs). METHODS: Measurements were obtained monocularly from pseudophakic patients with a PMMA IOL (Ophtec PC265y or Rayner 105U), spherical Acry

  15. Fabrication and optical properties of Alq 3 doped PMMA microsphere arrays templated by ZnO inverse opal structure

    Science.gov (United States)

    Fu, Ming; Deng, Lier; Zhao, Ailun; Wang, Yongsheng; He, Dawei

    2010-07-01

    PMMA microsphere arrays are fabricated by a double replicating method with common used polystyrene colloidal crystal template. High quality ZnO inverse opals formed by electrodeposition play the key role between the PMMA microsphere arrays and polystyrene colloidal crystals. The electrodeposition method has advantage on fabricating IO structures with high solid fraction. After the subsequently in-situ polymerization of MMA in the voids of ZnO inverse opals, the ZnO is removed by hydrochloric acid solution. Microsphere arrays fabricated by PMMA or PMMA doped with Alq 3 are prepared. Reflection stop bands are detected from the formed PMMA microsphere arrays. Solid fraction from 37% to 50% of the PMMA arrays can be formed by different in-situ polymerization modes of MMA. The photoluminescence of Alq 3 in the PMMA spheres is partly suppressed at the wavelength of the photonic stop band induced by PMMA arrays.

  16. An anti-reflection coating for use with PMMA at 193 nm

    Science.gov (United States)

    Yen, Anthony; Smith, Henry I.; Schattenburg, M. L.; Taylor, Gary N.

    1992-01-01

    An antireflection coating (ARC) for use with poly(methyl methacrylate) (PMMA) resist for ArF excimer laser lithography (193 nm) was formulated. It consists of PMMA and a bis-azide, 4.4-prime-diazidodiphenyl sulfone (DDS) which crosslinks the film after deep UV (260 nm) irradiation and subsequent annealing. The reacted DDS then serves as the absorber for the 193 nm radiation and also prevents mixing of the ARC and PMMA during PMMA spin-coating and development. The effectiveness of the ARC was demonstrated by exposing, in PMMA, using achromatic holographic lithography, gratings of 100 nm period (about 50 nm linewidth) that are almost entirely free of an orthogonal standing wave.

  17. PMMA microstructure as KrF excimer-laser LIGA material

    Science.gov (United States)

    Yang, Chii-Rong; Chou, Bruce C. S.; Chou, Hsiao-Yu; Lin, Frank H. S.; Kuo, Wen-Kai; Luo, Roger G. S.; Chang, Jer-Wei; Wei, Z. J.

    1998-08-01

    PMMA (polymethyl methacrylate) has been widely used as x-ray LIGA material for its good features of electrical acid plating of all common metals to industrial applications. Unlike the tough characteristics of polyimide in almost all alkaline and acid solutions, PMMA is easily removed in chemical etchants after electroplating process. For this reason, ablation- etching characteristics of PMMA material for 3D microstructures fabrication using a 248 nm KrF excimer laser were investigated. Moreover, the uses of the laminated dry film were also studied in this work. Experimental results show that PMMA microstructures can produce the near-vertical side- wall profile as the laser fluence up to 2.5 J/cm2. PMMA templates with high aspect ratio of around 25 were demonstrated, and the sequential electroplating processes have realized the metallic microstructures. Moreover, the microstructures fabricated in dry film show the perfect side- wall quality, and no residues of debris were found.

  18. Development, structure and strength properties of PP/PMMA/FA blends

    Indian Academy of Sciences (India)

    Navin Chand; S R Vashishtha

    2000-04-01

    A new type of flyash filled PP/PMMA blend has been developed. Structural and thermal properties of flyash (FA) filled polypropylene (PP)/polymethyl methacrylate (PMMA) blend system have been determined and analysed. Filled polymer blends were developed on a single screw extruder. Strength and thermal properties of FA filled and unfilled PP/PMMA blends were determined. Addition of flyash imparted dimensional and thermal stability, which has been observed in scanning electron micrographs and in TGA plot. Increase of flyash concentration increased the initial degradation temperature of PP/PMMA blend. The increase of thermal stability has been explained based on increased mechanical interlocking of PP/PMMA chains inside the hollow structure of flyash.

  19. Control of nanostructures generated in epoxy matrices blended with PMMA-b-PnBA-b-PMMA triblock copolymers

    Directory of Open Access Journals (Sweden)

    H. Kishi

    2015-01-01

    Full Text Available Stability of nanostructures of epoxy/acrylic triblock copolymer blends was studied.PMMA-b-PnBA-b-PMMA triblock copolymers (acrylic BCPs having several compositions on the ratio of the block chains and the molecular weight were initially prepared and were blended with diglycidyl ether of bisphenol-A epoxy thermosets. The blends were cured using phenol novolac with tri phenyl phosphine (TPP as the catalyst. Several nanostructures, such as spheres, cylinders, curved lamellae, were observed in the cured blends. The nanostructures were controlled by the molecular weight of the immiscible PnBA-block chain and the ratio of the PnBA in the blends. Moreover, the effect of the gel time to the nanostructures was examined by altering the trace amount of the TPP in the blends. The types of the nanostructures were almost kept irrespective of the gel time of the blends when the composition of the blends was maintained. This suggested the stability of the nanostructures of the epoxy/acrylic BCP blends made via the self-assembly mechanism, therefore a phase diagram of the cured blends was proposed.

  20. Photonic Band Gap in 1D Multilayers Made by Alternating SiO2 or PMMA with monolayer MoS2 or WS2

    CERN Document Server

    del Valle, Diana Gisell Figueroa; Scotognella, Francesco

    2015-01-01

    Atomically thin molybdenum disulphide (MoS2) and tungsten disulphide (WS2) are very interesting two dimensional materials for optics and electronics. In this work we show the possibility to obtain one-dimensional photonic crystals consisting of low-cost and easy processable materials, as silicon dioxide (SiO2) or poly methyl methacrylate (PMMA), and monolayers of MoS2 or WS2. We have simulated the transmission spectra of the photonic crystals using the transfer matrix method and employing the wavelength dependent refractive indexes of the materials. This study envisages the experimental fabrication of these new types of photonic crystals for photonic and light emission applications.

  1. Structural and Electrochemical Analysis of PMMA Based Gel Electrolyte Membranes

    Directory of Open Access Journals (Sweden)

    Chithra M. Mathew

    2015-01-01

    Full Text Available New gel polymer electrolytes containing poly(vinylidene chloride-co-acrylonitrile and poly(methyl methacrylate are prepared by solution casting method. With the addition of 60 wt.% of EC to PVdC-AN/PMMA blend, ionic conductivity value 0.398×10-6 S cm−1 has been achieved. XRD and FT-IR studies have been conducted to investigate the structure and complexation in the polymer gel electrolytes. The FT-IR spectra show that the functional groups C=O and C≡N play major role in ion conduction. Thermal stability of the prepared membranes is found to be about 180°C.

  2. Production of color centers in PMMA by ultrashort laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Elgul Samad, Ricardo, E-mail: resamad@gmail.co [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade universitaria 05508-000, Sao Paulo, SP (Brazil); Coronato Courrol, Lilia [Departamento de Ciencias Exatas e da Terra, UNIFESP, Diadema, SP (Brazil); Benevolo Lugao, Ademar; Zanardi Freitas, Anderson de; Dias Vieira, Nilson [Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, Cidade universitaria 05508-000, Sao Paulo, SP (Brazil)

    2010-03-15

    We report here the creation of color centers in commercial, transparent PMMA samples by ultrashort pulses from a Ti:Sapphire laser emitting at 800 nm, with spatial control. Although the 800 nm photon energy is not sufficient to ionize the polymer, the centers are created following a multiphotonic absorption that causes the ionization. We propose that the free electrons quivering motion on the pulse electric field displaces atoms from its equilibrium positions, creating free radicals and double bonds that coalesce into color centers. The absorption and emission spectra of the centers were measured, but a dose-like curve could not be built due to the presence of damages created along with the centers that scatter the excitation and emission lights due to the commercial sample's poor optical quality.

  3. UV-laser-assisted liquid phase fluorination of PMMA

    Science.gov (United States)

    Wochnowski, C.; Di Ferdinando, M.; Giolli, C.; Vollertsen, F.; Bardi, U.

    2007-10-01

    Polymethylmethacrylate (PMMA) substrate was covered with liquid 1,2,3,5-tetrafluorobenzene by spin coating. Then the sample was irradiated by a KrF-excimer laser ( λ = 248 nm). Thus, fluorine is released from the fluorine-containing precursor diffusing into the polymeric substrate material where it is expected to substitute the hydrogen atoms of the polymeric molecule and form a water-repellent (hydrophobic) fluorinated polymer. After drying out the polymeric substrate, the sample surface was investigated by SEM, EDX, XPS and contact angle measurement method in order to determine the fluorine content and the wettability of the treated polymeric surface as well as the substitution sites inside the polymeric molecule. The measurements indicate some chemically bonded fluorine at the top of the sample layer. A UV-photochemical fluorination mechanism is proposed based on the XPS spectra evaluation.

  4. Vibration Properties of a Steel-PMMA Composite Beam

    Directory of Open Access Journals (Sweden)

    Yuyang He

    2015-01-01

    Full Text Available A steel-polymethyl methacrylate (steel-PMMA beam was fabricated to investigate the vibration properties of a one-dimensional phononic crystal structure. The experimental system included an excitation system, a signal acquisition system, and a data analysis and processing system. When an excitation signal was exerted on one end of the beam, the signals of six response points were collected with acceleration sensors. Subsequent signal analysis showed that the beam was attenuated in certain frequency ranges. The lumped mass method was then used to calculate the bandgap of the phononic crystal beam to analyze the vibration properties of a beam made of two different materials. The finite element method was also employed to simulate the vibration of the phononic crystal beam, and the simulation results were consistent with theoretical calculations. The existence of the bandgap was confirmed experimentally and theoretically, which allows for the potential applications of phononic crystals, including wave guiding and filtering, in integrated structures.

  5. Polyaniline nanofibers as a new gamma radiation stabilizer agent for PMMA

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available Polyanilines are reported to exhibit stabilizing effects in rubber mixtures submitted to gamma-irradiation and thermo-oxidative treatment. Such abilities may be explained by their action as radical scavengers. Since radical formation followed by main chain scission is a widely accepted mechanism for radiolytic degradation of PMMA, polyaniline is a promising additive for commercial plastics submitted to radiosterilization processing. In this work, we investigated the ability of polyaniline emeraldine salt nanofibers (PANF-HCl in preventing radiation damage on PMMA matrix. Effects of gamma-irradiation on PMMA/PANF-HCl composites films were assessed by comparison of the variation of viscosity-average molar mass (Mv of PMMA at 25 kGy dose when compared to commercial PMMA films. Samples containing 0.15% PANF-HCl (wt/wt retained 92% of the initial Mv after irradiation while control sample presented 42% of Mv retention. When exposed to 60-200 kGy doses, PANF-HCl embedded into PMMA matrix preserved their oxidation state but started to exhibit mild deprotonation. PANF-HCl nanofibers were characterized by Diffuse Reflection Infrared Fourier Transform Spectroscopy (DRIFTS and Scanning Electronic Microscopy (SEM. PMMA/PANF-HCl composites films were characterized by SEM and UV-VIS spectroscopy.

  6. Inclusion of marbofloxacin in PMMA orthopaedic cement: an in vitro experimental study.

    Science.gov (United States)

    Cariou, M; Boulouis, H J; Moissonnier, P

    2006-01-01

    This in vitro experimental study investigated the feasibility for marbofloxacin, a veterinary fluoroquinolone antibiotic, to retain its antibacterial activity after its inclusion in polymethylmethacrylate (PMMA) cement. The assays were conducted on gelose cultures of various types of bacteria isolated from canine spontaneous osteomyelitis. The efficiency of the antibiotics was assessed by using an antibiogram method. Resistance of marbofloxacin to the temperature observed during PMMA polymerization, antimicrobial effect of galenic, useful concentrations and comparison with gentamicin (reference antibiotic for this use) were evaluated. Marbofloxacin retained its antimicrobial activity after being heated to high temperatures reached during polymerization. The more effective galenic form to incorporate into the PMMA monomer was the marbofloxacin powder and the appropriate concentration was 1/40 degrees . In this experiment, marbofloxacin included in PMMA showed a good antimicrobial activity; however this activity was lower than gentamicin added to PMMA on Gram + and Pseudomonas bacteria.Therefore, it seems useful to incorporate marbofloxacin to PMMA cement to treat, or to prevent, osteomyelitis associated with marbofloxacin sensitive bacteria. Nevertheless, the development of a marbofloxacin-PMMA cement requires further evaluation, especially pharmacological, biomechanical and clinical.

  7. Tailoring of optical and electrical properties of PMMA by incorporation of Ag nanoparticles

    Indian Academy of Sciences (India)

    ALISHA GOYAL; ANNU SHARMA; ISHA SAINI; NAVNEET CHANDAK; PAWAN SHARMA

    2017-08-01

    Silver–poly(methyl methacrylate) (Ag–PMMA) nanocomposite films were prepared via ex situ chemical routeby employing sodium borohydride (NaBH$_4$) as a reducing agent. In this study, PVP-stabilized Ag nanoparticles were prepared and mixed with PMMA solution. Optical and structural characterizations of resulting nanocomposite films were performedusing UV–visible spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Characteristicsurface plasmon resonance (SPR) peak of Ag nanoparticles was observed at about 3.04 eV (408 nm) in absorptionspectra of Ag–PMMA nanocomposite films. TEM micrograph revealed that the spherical Ag nanoparticles with an averagediameter of $5.4\\pm 2.5$ nm are embedded in PMMA. In Raman spectra, besides shifting of vibrational bands, enhancementin intensity of Raman signal with incorporation of Ag nanoparticles was observed. Current ($I$)–voltage ($V$) measurementsrevealed that conductivity of PMMA increased with increasing concentration of Ag nanoparticles. Analysis of $I-V$ datafurther disclosed that at voltage $\\lt$2 V, ohmic conduction mechanism is the dominant mechanism, while at voltage $\\gt$2 VPoole–Frenkel is the dominant conduction mechanism. Urbach’s energy, the measure of disorder, increased from 0.40 eVfor PMMA to 1.11 eV for Ag–PMMA nanocomposite films containing 0.039 wt% of Ag nanoparticles.

  8. Synthesis and investigation of PMMA films with homogeneously dispersed multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Pantoja-Castro, M.A., E-mail: m_pantojaq@yahoo.com.mx [Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Av. J. Múgica S/N Col., Villa Universidad, CP 58040 Morelia, Michoacán (Mexico); Pérez-Robles, J.F. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Libramiento Norponiente #2000, Fracc. Real de Juriquilla, CP 76230 Querétaro (Mexico); González-Rodríguez, H. [Facultad de Ingeniería Química, Universidad Michoacana de San Nicolás de Hidalgo, Av. J. Múgica S/N Col., Villa Universidad, CP 58040 Morelia, Michoacán (Mexico); Vorobiev-Vasilievitch, Y. [Centro de Investigación y de Estudios Avanzados del IPN, Unidad Querétaro, Libramiento Norponiente #2000, Fracc. Real de Juriquilla, CP 76230 Querétaro (Mexico); Martínez-Tejada, H.V. [Instituto de Energía, Materiales y Medio Ambiente, Universidad Pontificia Bolivariana, Circular 1 No. 70-01, Bloque 22, Medellín (Colombia); Velasco-Santos, C. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Autónoma de México, Av. Boulevard Juriquilla, No. 3001 Juriquilla, CP 76230 Querétaro (Mexico)

    2013-07-15

    Multiwalled carbon nanotubes (MWNT) modified by 2.2′-azoiso-butyronitrile (AIBN) were incorporated into methyl methacrylate (MMA) by sonochemistry method, resulting in homogenous dispersion of MWNT, which makes possible to obtain flexible conductive polymer-matrix nanocomposites films of PMMA, with MWNT concentrations ranging from 0 to 0.5 wt%. Modified MWNT (AIBN-MWNT) were studied by Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and through visual observations in order to compare the dispersion in 2-propanone and toluene with that of pristine MWNT. Synthesized PMMA-AIBN-MWNT films were studied by FT-IR and Raman spectroscopy. Using FT-IR for the AIBN-MWNT it was not possible to identify any group or groups attached to the nanotubes. Raman spectroscopy shows a small modification in the Lorentzian peaks ratio I{sub D/G} of AIBN-MWNT, meanwhile XPS showed that atomic compositions does not change for AIBN-MWNT compared to the pristine nanotubes. Also by impedance it was analyzed the conductivity of PMMA-MWNT films and the results showed a threshold percolation at 0.5 wt%. FT-IR and Raman analyses for PMMA-AIBN-MWNT composite indicate a covalent bonding between PMMA and MWNT due to the opening of π-bonds of the nanotubes, which is related with a possible proposed reaction scheme. - Graphical abstract: Display Omitted - Highlights: • We used sonochemistry-in situ polymerization to disperse MWNT very soon in PMMA. • A high and homogenous dispersion of MWNT in PMMA was achieved. • The modification of MWNT by AIBN was analyzed using Raman. • A covalent bonding between PMMA and MWNT was analyzed by FT-IR and Raman. • According to the results of PMMA-MWNT it was proposed a scheme reaction.

  9. Effect of zinc oxide on flexural and physical properties of PMMA composites

    Science.gov (United States)

    Hamad, Wan Nur Fadilla Wan; Abdullah, Abdul Manaf; Mohamad, Dasmawati

    2016-12-01

    Polymethylmethacrylate (PMMA) is the most widely accepted material in maxillofacial implants due to its superior advantages. The material used for craniofacial implant should have good mechanical and antibacterial properties to withstand forces and eliminate infection. A study was conducted to prepare PMMA incorporated with β-tricalcium phosphate (β -TCP) filler and zinc oxide as an antibacterial agent at different compositions and investigate the flexural properties of the produced PMMA/β- TCP/ZnOcomposites. Pure PMMA as control,15 % β -TCP filled, 15% β -TCPwith 2.5% ZnO filled as well as15% β -TCPwith5% ZnOfilled PMMA were prepared. PMMA were mixed together with β -TCP and zinc oxide manually according to the percentages specified until it has reached the homogeneous state. Flexural specimens were prepared by casting the paste in silicone mould which has been fabricated using 3D printed flexural template. The number of samples was n=7 for each composition. Statistical analysis of One Way ANOVA was employed to compare the flexural properties of each samples. Flexural strength of pure PMMA,15 % β -TCP filled, 15% β -TCP with 2.5% ZnO filled as well as 15% β -TCP with 5% ZnO filled PMMA were 60.79, 46.75, 38.72 and 41.49 MPa respectively. The addition of either β- TCP or β- TCP with ZnO decreased the flexural properties and it showed significant differences as compared to pure PMMA (p0.05).

  10. Raman spectra of bilayer graphene covered with Poly(methyl methacrylate thin film

    Directory of Open Access Journals (Sweden)

    Minggang Xia

    2012-09-01

    Full Text Available The Raman spectra of bilayer graphene covered with poly(methyl methacrylate (PMMA were investigated. Both the G and 2D peaks of PMMA-coated graphene were stiff and broad compared with those of uncovered graphene. This could be attributed to the residual strain induced by high-temperature baking during fabrication of the nanodevice. Furthermore, the two 2D peaks stiffened and broadened with increasing laser power, which is just the reverse to uncovered graphene. The stiffness is likely caused by graphene compression induced by the circular bubble of the thin PMMA film generated by laser irradiation. Our findings may contribute to the application of PMMA in the strain engineering of graphene nanodevices.

  11. Study on the thermo-optic properties of DR1/PMMA composite

    Institute of Scientific and Technical Information of China (English)

    Li Xiang; Cao Zhuang-Qi; Shen Qi-Shun; Yang Yan-Fang

    2006-01-01

    This paper reports that the thermo-optic coefficient (dn/dT) as well as thermal expansion coefficients (β) of DR1/PMMA polymer film are measured for both TE (transversal electric) and TM (transversal magnetic) polarizations by using an attenuated total reflection configuration at the wavelengths of 832nm. The thermo-optic coefficients of DR1/PMMA are negative and as high as the order of 10-4/°C. The influences of dopant concentration, poling process and photobleaching process on the thermo-optic properties of DR1/PMMA are also investigated.

  12. Effect of Ag Nanoparticles on Optical Properties of R6G Doped PMMA Films

    Institute of Scientific and Technical Information of China (English)

    DENG Yan; SUN You-Yi; WANG Pei; ZHANG Dou-Guo; JIAO Xiao-Jin; MING Hai; ZHANG Qi-Jing; JIAO Yang; SUN Xiao-Quan

    2007-01-01

    The composite PMMA films containing Ag nanoparticles and rhodamine 6G are prepared.We investigate the fluorescence Droperties and nonlinear optical properties of R6G/PMMA films influenced by Ag nanoparticles.The fluorescence enhancement factor is about 3.3.The corresponding nonlinear refractive index is measured to be-2.423×10-8 esu using the Z-scan technique,which is much enhanced compared with the R6G/PMMA film.The results indicate that these enhancements are attributed to surface plasmon resonance of Ag nanoparticles.

  13. PMMA with Long-Persistent Phosphors and Its Behavior of Luminescence

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new kind of rare earth material with high efficient long-persistent phosphors, such as SrAl2O4:Eu, Dy, has been developed in recent years. The PMMA with long-persistent phosphors is typical one of applications for the phosphors. In this work, we try to probe into the affection of the manufacture process on the PMMA with long-persistent phosphors, to analyze its performance, and its luminescence behavior, especially to study the self-excitation of the PMMA with long-persistent phosphors.

  14. Controlling the Pore Size of Mesoporous Carbon Thin Films through Thermal and Solvent Annealing.

    Science.gov (United States)

    Zhou, Zhengping; Liu, Guoliang

    2017-02-02

    Herein an approach to controlling the pore size of mesoporous carbon thin films from metal-free polyacrylonitrile-containing block copolymers is described. A high-molecular-weight poly(acrylonitrile-block-methyl methacrylate) (PAN-b-PMMA) is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The authors systematically investigate the self-assembly behavior of PAN-b-PMMA thin films during thermal and solvent annealing, as well as the pore size of mesoporous carbon thin films after pyrolysis. The as-spin-coated PAN-b-PMMA is microphase-separated into uniformly spaced globular nanostructures, and these globular nanostructures evolve into various morphologies after thermal or solvent annealing. Surprisingly, through thermal annealing and subsequent pyrolysis of PAN-b-PMMA into mesoporous carbon thin films, the pore size and center-to-center spacing increase significantly with thermal annealing temperature, different from most block copolymers. In addition, the choice of solvent in solvent annealing strongly influences the block copolymer nanostructure and the pore size of mesoporous carbon thin films. The discoveries herein provide a simple strategy to control the pore size of mesoporous carbon thin films by tuning thermal or solvent annealing conditions, instead of synthesizing a series of block copolymers of various molecular weights and compositions.

  15. On the electrical arc interruption by using PMMA/iron oxide nanocomposites

    Science.gov (United States)

    Doddapaneni, Venkatesh; Saleemi, Mohsin; Ye, Fei; Gati, Rudolf; Toprak, Muhammet S.

    2016-10-01

    An experimental study is undertaken on the fabrication of poly (methyl methacrylate) (PMMA)/iron oxide nanocomposites to determine their potential use for electrical arc interruption in the electrical switching applications such as circuit breakers. Monodisperse iron oxide nanoparticles of average size ∼11 nm are synthesized via thermal decomposition method and then homogeneously dispersed in the PMMA matrix by in situ polymerization. PMMA/iron oxide nanocomposites with different nanoparticle loading have been fabricated to study the effect of loading content on the thermal energy absorption. Detailed physicochemical characterizations on synthesized material are performed using x-ray powder diffraction, scanning electron microscopy, TEM, thermogravimetric analysis and differential scanning calorimetry at different processing stages. A test-setup was designed to evaluate the quality of the nanocomposites for electric arc interruption capability. The results showed that PMMA/iron oxide nanocomposites have a clear impact on the electric arc interruption and therefore should be considered as promising candidates for electrical switching applications.

  16. Reduction of cytotoxicity of natural rubber latex film by coating with PMMA-chitosan nanoparticles.

    Science.gov (United States)

    Kanjanathaworn, Nuttakun; Polpanich, Duangporn; Jangpatarapongsa, Kulachart; Tangboriboonrat, Pramuan

    2013-08-14

    Poly(methyl methacrylate) (PMMA) latex stabilized by chitosan (CS) oligomer was synthesized via the miniemulsion polymerization. By using 1% CS solution (in 0.1M acetic acid), the spherical PMMA-CS particles with an average size of 380 nm were obtained. The positive zeta potentials at pH 2-7 confirmed the presence of CS as the outermost layer of the latex particles. Therefore, these particles directly interacted with the indigenous non-rubbers at the surface of sulphur prevulcanized natural rubber (SPNR) film. The deposition of PMMA-CS particles caused an increase in surface roughness of the coated SPNR film as a function of latex concentration and immersion time. The simple coating of the rubber substrate with PMMA-CS particles effectively reduced the in vitro cytotoxicity on L-929 cells. This study would be, therefore, helpful for development of latex gloves designed for hypersensitive users.

  17. In vitro cytotoxicity evaluation of natural rubber latex film surface coated with PMMA nanoparticles.

    Science.gov (United States)

    Anancharungsuk, Waranya; Polpanich, Duangporn; Jangpatarapongsa, Kulachart; Tangboriboonrat, Pramuan

    2010-07-01

    In order to increase surface roughness of the sulphur-prevulcanized natural rubber (SPNR) film and, hence, decrease the direct contact between the rubber and skin, the poly(methyl methacrylate) (PMMA) latex particles were deposited onto the SPNR film grafted with polyacrylamide (SPNR-g-PAAm). The surface coverage of PMMA particles on the SPNR-g-PAAm increased with increasing latex immersion time, particle size and concentration. Prior to the in vitro cytotoxicity evaluation on L-929 fibroblasts, the SPNR and SPNR-g-PAAm coated with PMMA particles were extracted by using the culture medium. Results showed that the cytotoxicity effect could be significantly reduced by coating PMMA particles onto the rubber film. At the extract concentrations of < or =12.5% for 24h at 37 degrees C, no toxicity potential was detected. The study will be helpful for development of gloves designed for the hypersensitive person.

  18. Optical absorption and photoluminescence properties of ZnO/PMMA nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Kulyk, B; Kapustianyk, V [Department of Physics, Scientific and Educational Center ' Fractal' , Scientific-Technical and Educational Center of Low Temperature Studies, Ivan Franko National University of L' viv, 50 Dragomanova Str., L' viv (Ukraine); Krupka, O [Department of Chemistry, Kyiv Taras Shevchenko National University, 60 Volodymyrska Str., Kyiv (Ukraine); Sahraoui, B, E-mail: bohdan_kulyk@yahoo.com [Department of Physics, University of Angers, 2 Lavoisier Av., Angers (France)

    2011-04-01

    The ZnO nanocrystals (ZnO NCs) with particle size, less than 100 nm, have been blended with polymethylmethacrylate (PMMA) by solution mixing to prepare PMMA/ZnO nanocomposite films. The structure of ZnO/PMMA nanocomposite films was characterized using X-ray diffractometry. The prepared nanocomposite films are highly transparent and a clear excitonic peak is observed in their absorption spectra. Measurements of temperature evolution of the photoluminescence (PL) spectra show intensive UV emission peak corresponding to the donor-bound excitons with binding energy of 51 meV and green emission band related to the intrinsic defects in ZnO. The temperature evolution of the emission peaks energy position, intensity and integral intensity in ZnO/PMMA nanocomposite films were examined.

  19. Functionalization of Poly- (methyl methacrylate) (PMMA) as a substrate for DNA microarrays

    DEFF Research Database (Denmark)

    Fixe, A.F.; Dufva, Hans Martin; Telleman, Pieter

    2004-01-01

    amines was confirmed by the immobilization of DNA probes and hybridization with a complementary DNA strand. The hybridization signal and the hybridization efficiency of the chemically aminated PMMA slides were comparable to the hybridization signal and the hybridization efficiency obtained from...... since the hybridization performance of microarrays subjected to 20 PCR heat cycles was only reduced by 4%. In conclusion, this new strategy to modify PMMA provides a robust procedure to immobilize DNA, which is a very useful substrate for fabricating single use diagnostics devices with integrated......A chemical procedure was developed to functionalize poly(methyl methacrylate) (PMMA) substrates. PMMA is reacted with hexamethylene diamine to yield an aminated surface for immobilizing DNA in microarrays. The density of primary NH2 groups was 0.29 nmol/cm(2). The availability of these primary...

  20. Synthesis and Characterization of Ca, Mg, La- PMMA Polymer Composites for Phosphate Removal

    Science.gov (United States)

    In this study calcium, magnesium and lanthanum- PMMA polymer composites were synthesized, characterized and investigated for phosphate removal from wastewater using rapid small scale column tests. Theoretical and experimental capacity of the media was determined and unused and sp...

  1. Printed wax masks for 254 nm deep-UV pattering of PMMA-based microfluidics

    KAUST Repository

    Fan, Yiqiang

    2012-01-13

    This paper reports a new technique for masking deep-UV exposure of poly(methyl methacrylate) (PMMA) using a printed wax mask. This technique provides an inexpensive and bulk fabrication method for PMMA structures. The technique involves the direct printing of the mask onto a polymer sheet using a commercial wax printer. The wax layer was then transferred to a PMMA substrate using a thermal laminator, exposed using deep-UV (with a wavelength of 254 nm), developed in an IPA:water solution, and completed by bonding on a PMMA cap layer. A sample microfluidic device fabricated with this method is also presented, with the microchannel as narrow as 50 μm. The whole process is easy to perform without the requirement for any microfabrication facilities. © 2012 IOP Publishing Ltd.

  2. Characterisation of PMMA/ATH Layers Realised by Means of Atmospheric Pressure Plasma Powder Deposition

    Directory of Open Access Journals (Sweden)

    Lena M. Wallenhorst

    2015-01-01

    Full Text Available We report on the characteristics of aluminium trihydrate filled poly(methyl methacrylate composite (PMMA/ATH coatings realised by plasma deposition at atmospheric pressure. For this purpose, PMMA/ATH powder was fed to a plasma jet where the process and carrier gas was compressed air. The deposited coatings were investigated by X-ray photoelectron spectroscopy and water contact angle measurements. Further, the raw material was characterised before deposition. It was found that, with respect to the raw material, aluminium was uncovered in the course of the plasma deposition process which can be explained by plasma-induced etching of the PMMA matrix. As a result, the wettability of plasma-deposited PMMA/ATH was significantly increased. Even though a uniform coating film could not be realised as ascertained by confocal laser scanning microscopy, the deposited coatings feature notably enhanced characteristics which could be advantageous for further processing.

  3. Experimental investigation of interface curing stresses between PMMA and composite using digital speckle correlation method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper studies the interface curing stresses between polymethyl methacrylate (PMMA) and composite by means of digital speckle correlation method (DSCM).A new method by combining DSCM with the marker points is developed to measure the interface curing stresses,and the measurement principle is introduced.The interface curing stresses between PMMA and composite with different curing bonding conditions are measured and analyzed,this indicates that the residual stress for furnace heating and furnace cooling ...

  4. PM567-Doped solid dye lasers based on PMMA

    Institute of Scientific and Technical Information of China (English)

    Li Xiao-Hui; Fan Rong-Wei; Xia Yuan-Qin; Liu Wei; Chen De-Ying

    2007-01-01

    Polymers are a kind of attractive hosts for laser dyes due to their high transparency in both pumping and lasing ranges and superior optical homogeneity. In this paper solid dye samples based on polymethyl methacrylate (PMMA)doped with different concentrations of 1, 3, 5, 7, 8 -pentamethyl-2, 6-diethylpyrromethene-BF2 (PM567) are prepaed.The absorption, fluorescence and lasing spectra of the samples are obtained. Wide absorption and fluorescence bands are obtained and a red shift of the maxima of the lasing emission spectra is observed. With the second-harmonic generation of Q-switched Nd:YAG laser (532 nm, ~20 ns) pumping the samples longitudinally, the slope efficiencies of the samples are obtained. There is an optimal dye concentration for the highest slope efficiency when the pumping energy is lower than some typical value (~250 m J), and the highest slope efficiency 35.6% is obtained in the sample with a dye concentration of 2 × 10-4 mol/L. Pumping the samples at a rate of 10Hz with a pulse energy as high as 200 mJ (the fluence is 0.2J/cm2), the output energy drops to one-half of its initial value after approximate 15500 pulses and the normalized photostability is 5.17GJ/mol. A kind of solid dye laser which could have some applications is built.

  5. Fully dry PMMA transfer of graphene on h-BN using a heating/cooling system

    Science.gov (United States)

    Uwanno, T.; Hattori, Y.; Taniguchi, T.; Watanabe, K.; Nagashio, K.

    2015-12-01

    The key to achieve high-quality van der Waals heterostructure devices made of stacking various two-dimensional (2D) layered materials lies in the clean interface without bubbles and wrinkles. Although polymethylmethacrylate (PMMA) is generally used as a sacrificial transfer film due to its strong adhesion property, it is always dissolved in the solvent after the transfer, resulting in the unavoidable PMMA residue on the top surface. This makes it difficult to locate clean interface areas. In this work, we present a fully dry PMMA transfer of graphene onto h-BN using a heating/cooling system which allows identification of clean interface area for high quality graphene/h-BN heterostructure fabrication. The mechanism lies in the utilization of the large difference in thermal expansion coefficients between polymers (PMMA/PDMS) and inorganic materials (graphene/h-BN substrate) to mechanically peel off PMMA from graphene by the thermal shrinkage of polymers, leaving no PMMA residue on the graphene surface. This method can be applied to all types of 2D layered materials.

  6. Mechanical Properties and Cytocompatibility Improvement of Vertebroplasty PMMA Bone Cements by Incorporating Mineralized Collagen

    Directory of Open Access Journals (Sweden)

    Hong-Jiang Jiang

    2015-05-01

    Full Text Available Polymethyl methacrylate (PMMA bone cement is a commonly used bone adhesive and filling material in percutaneous vertebroplasty and percutaneous kyphoplasty surgeries. However, PMMA bone cements have been reported to cause some severe complications, such as secondary fracture of adjacent vertebral bodies, and loosening or even dislodgement of the set PMMA bone cement, due to the over-high elastic modulus and poor osteointegration ability of the PMMA. In this study, mineralized collagen (MC with biomimetic microstructure and good osteogenic activity was added to commercially available PMMA bone cement products, in order to improve both the mechanical properties and the cytocompatibility. As the compressive strength of the modified bone cements remained well, the compressive elastic modulus could be significantly down-regulated by the MC, so as to reduce the pressure on the adjacent vertebral bodies. Meanwhile, the adhesion and proliferation of pre-osteoblasts on the modified bone cements were improved compared with cells on those unmodified, such result is beneficial for a good osteointegration formation between the bone cement and the host bone tissue in clinical applications. Moreover, the modification of the PMMA bone cements by adding MC did not significantly influence the injectability and processing times of the cement.

  7. Surface modification of PMMA/O-MMT composite microfibers by TiO 2 coating

    Science.gov (United States)

    Wang, Qingqing; Wang, Xin; Li, Xuejia; Cai, Yibing; Wei, Qufu

    2011-10-01

    In the present work, poly(methyl methacrylate) (PMMA)/organically modified montmorillonite (O-MMT) composite microfibers were firstly prepared by emulsion polymerization combined with electrospinning, and then coated by nanosize titanium dioxide (TiO 2) using RF magnetron sputter technique. The modified surfaces of PMMA/O-MMT composite microfibers were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), UV-vis spectroscopy and drop shape analyzer. Finally, the photocatalytic properties of TiO 2 coated PMMA/O-MMT composite microfiber membranes were evaluated by degradation of methylene blue(MB) under UV illumination. The experimental results revealed that anatase-TiO 2 and rutile-TiO 2 nanoparticles were well spread and physically deposited on the surface of PMMA/O-MMT microfibers, and the wettability of the PMMA/O-MMT composite microfibers was improved after surface modification by sputter coating. Furthermore, the PMMA/O-MMT microfibers membrane coated with TiO 2 performed well in photocatalytic degradation of MB.

  8. Preparation and Ordered Self-Assembly of Nano-Pd-Ga/PMMA by Ultrasonic

    Directory of Open Access Journals (Sweden)

    Xu Guo Cai

    2011-01-01

    Full Text Available Nano-Ga-Pd/poly methyl methacrylate (PMMA composite materials were prepared with the palladium chloride solution containing metal gallium, MMA as monomer, and sodium dodecyl sulfate (SDS as emulsifier without initiatoror reducer. Pd, Ga, and Ga5Pd phase in PMMA matrix were identified by XRD. The characteristic absorption peak at 200 nm for nano-Ga/PMMA polymer solution, at 209 nm for nano-Pd/PMMA polymer solution were proved by UV-Vis; the binding energy changes of O1s, Ga2p3, Ga2d, and Pd3d were characterized by means of X-ray photoelectron spectroscopy. It is concluded that nano-Ga5Pd was produced based on segment electronics shifting from Gallium to Palladium, and coordination was formed on segment electronics from Gallium to oxygen of PMMA ester group. The anisotropism ordered assembly of PMMA around nano-Ga-Pd particles were illuminated by transmission electron microscopy; it is further interpreted that nano Ga-Pd particles had ordered-assembly induced effect.

  9. Effect of high-pressure polymerization on mechanical properties of PMMA denture base resin.

    Science.gov (United States)

    Murakami, Natsuko; Wakabayashi, Noriyuki; Matsushima, Rie; Kishida, Akio; Igarashi, Yoshimasa

    2013-04-01

    The aim of this study was to assess the effect of high-pressure polymerization on mechanical properties of denture base resin. A heat-curing denture base resin and an experimental PMMA were polymerized under 500MPa of pressure by means of an isostatic pressurization machine at 70°C for 24h to make rectangular specimens whose dimensions were 30mm×2mm×2mm. Each specimen was deflected on a three-point flexural test until either fracture occurred or the sample was loaded up to 8mm in deflection. The molecular weight of the PMMA without filler was analyzed using the high-speed liquid chromatography system. Increased ductility without fracture was shown in the specimens subjected to high pressure, while most of the control specimens (ambient pressure) fractured. The mean toughness of the PMMA specimens polymerized under the high pressure was significantly higher than the same material polymerized under ambient pressure (ppressure groups of the denture resin and the PMMA revealed a significantly lower mean 0.2% yield stress, flexural strength, and elastic modulus than control groups (ppressure specimens than were present in the controls. The increased toughness shown in the PMMA polymerized under the high pressure was presumably attributed to the higher molecular weight produced by the pressure. The result suggests a potential application of the high-pressure polymerization to the development of PMMA-based denture resin with improved fracture resistance.

  10. Directed self-assembly materials for high resolution beyond PS-b-PMMA

    Science.gov (United States)

    Hirahara, Eri; Paunescu, Margareta; Polishchuk, Orest; Jeong, EunJeong; Ng, Edward; Shan, Jianhui; Yin, Jian; Kim, Jihoon; Cao, Yi; Li, Jin; Hong, SungEun; Baskaran, Durairaj; Lin, Guanyang

    2016-03-01

    To extend directed self-assembly (DSA) of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) for higher resolution, placement accuracy and potentially improved pattern line edge roughness (LER), we have developed a next-generation material platform of organic high-χ block copolymers ("HC series", AZEMBLYTM EXP PME-3000 series). The new material platform has a built-in orientation control mechanism which enables block copolymer domains to vertically selforient without topcoat/additive or delicate solvent vapor annealing. Furthermore, sub-10 nm lines and spaces (L/S) patterning by two major chemoepitaxy DSA, LiNe and SMARTTM processes, was successfully implemented on 12" wafer substrates by using the PME-3000 lamellar series. The results revealed that the new material platform is compatible with the existing PS-b-PMMA-based chemical prepatterns and standard protocols. We also introduced the built-in orientation control strategy to the conventional PS-b-PMMA system, producing a new generation of PS-b-PMMA materials with facile orientation control. The modified PS-b-PMMA (m-PS-b-PMMA) performed LiNe flow DSA yielding a comparable CD process window with improved LER/LWR/SWR after the L/S patterns were transferred into a Si substrate.

  11. Surface modification of stainless steel orthopedic implants by sol-gel ZrTiO4 and ZrTiO4-PMMA coatings.

    Science.gov (United States)

    Salahinejad, E; Hadianfard, M J; Macdonald, D D; Sharifi Asl, S; Mozafari, M; Walker, K J; Rad, A Tahmasbi; Madihally, S V; Vashaee, D; Tayebi, L

    2013-08-01

    In this paper, the biocompatibility of a medical-grade stainless steel coated with sol-gel derived, nanostructured inorganic ZrTiO4 and hybrid ZrTiO4-PMMA thin films is correlated with surface characteristics. The surfaces of the samples are characterized by atomic force microscopy, the sessile drop technique, and electrochemical corrosion experiments. The viability of adult human mesenchymal stem cells on the surfaces after one day of culture is also assessed quantitatively and morphologically. According to the results, both of the coatings improve the hydrophilicity, corrosion resistance, and thereby cytocompatibility of the substrate. Despite the higher corrosion protection by the hybrid coating, the sample coated with the inorganic thin film exhibits a better cell response, suggesting the domination of wettability. In summary, the ZrTiO4-based sol-gel films can be considered to improve the biocompatibility of metallic implants.

  12. Effects of block copolymer self-assembly on optical anisotropy in azobenzene-containing PS-b-PMMA films

    Science.gov (United States)

    Orofino, A. B.; Camezzana, M. F.; Galante, M. J.; Oyanguren, P. A.; Zucchi, I. A.

    2012-03-01

    Polystyrene-b-polymethylmethacrylate (PS-b-PMMA) was selected as the host for 4-(4-nitrophenylazo)aniline (Disperse Orange 3, DO3) based on a previous study of DO3/PMMA and DO3/PS binary blends. Selective location of DO3 into the PMMA block of the copolymer was expected during self-assembly of the block copolymer since a preferential interaction of DO3 with PMMA has been demonstrated. However, surface segregation of DO3 was found during the thermal annealing used to nanostructure the copolymer. To avoid this, a thermoplastic polymer (Azo-TP) was synthesized from the bulk reaction of DO3 and diglycidyl ether of bisphenol A (DGEBA). The choice of DGEBA as a co-reactant was an attempt to encourage the selective location of azo groups in the PMMA phase of PS-b-PMMA. An inspection of solutions of Azo-TP in PS and PMMA, corroborates the preferential affinity of Azo-TP for PMMA. The Azo-TP could be satisfactorily dissolved in PS-b-PMMA. We have investigated the growth and decay processes of the optically induced birefringence in films of PS-b-PMMA containing 12 wt% Azo-TP. The resulting materials showed a good photoinduced time response, high maximum birefringence and an elevated fraction of remnant anisotropy.

  13. Optical transmission of PMMA optical fibres exposed to high intensity UVA and visible blue light

    Science.gov (United States)

    Alobaidani, A. D.; Furniss, D.; Johnson, M. S.; Endruweit, A.; Seddon, A. B.

    2010-05-01

    Optical transmission of PMMA (polymethylmethacrylate) POF (polymer optical fibre) in the spectral range from 280 to 450 nm is investigated with a high radiation emission source comprising a mercury lamp delivering 40 W/cm 2 at the PMMA POF launch face. The heat generated from the radiation source causes a sudden drop in the launched radiation due to thermal-oxidation and photo-degradation of the launch face of the PMMA POF; this results in a loss of 53% of the total launched power within 13 min of exposure to the source. The thermal-oxidation degradation is controlled by a cooling device which improves the transmission stability of the fibre. However, photo-degradation is still active and causes a loss in power of 7% in 13 min. The spectral output of the transmitted radiation through the PMMA POF was monitored and indicates the variation in optical loss with wavelength. High rates of nominal absorption for the irradiated PMMA POF are found below 320 nm wavelength. From the Beer-Lambert law, the photo-degradation effect with time of a fixed path length of PMMA POF is described by the absorption coefficient ( αλ, cm -1) . The nominal absorption coefficient αλ values in the range 335-368 nm wavelength are found to be higher after 1 h of irradiation than the values in the range 406-438 nm. However, the relative change in the nominal absorption coefficient Δ αλ is greater at 438 nm than at 335 nm, 368 or 406 nm. After 1 h of irradiation with the cooling device in place, the PMMA POF transmission was reduced to 44.8% of its initial value; this recovered to a maximum of 86% of the original transmission of the total launched power after 5 weeks in ambient conditions.

  14. Influence of P3HT concentration on morphological, optical and electrical properties of P3HT/PS and P3HT/PMMA binary blends

    Energy Technology Data Exchange (ETDEWEB)

    Nicho, M.E., E-mail: menicho@uaem.mx [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos (Mexico); Garcia-Escobar, C.H. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos (Mexico); Arenas, M.C. [Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, Boulevard Juriquilla No. 3001, Juriquilla, Queretaro, C.P. 76230 (Mexico); Altuzar-Coello, P. [Centro de Investigacion en Energia, UNAM, C.P. 62580, Temixco, Morelos (Mexico); Cruz-Silva, R.; Gueizado-Rodriguez, M. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209, Cuernavaca, Morelos (Mexico)

    2011-10-25

    Poly(3-hexylthiophene) (P3HT) has interesting optoelectronic properties and a wide variety of applications such as solar cells and O-FET devices. It is a soluble conductive polymer but their mechanical properties are poor and its conductivity is unstable in environmental condition. With the finality of overcome these disadvantages, P3HT binary blends with two insulating polymers, polystyrene (PS) and polymethylmetacrilate (PMMA), have been synthesized by direct oxidation of 3-hexylthiophene with FeCl{sub 3} as oxidant inside the insulator polymers. Molecular weight and polydispersity of P3HT polymer were measured by size exclusion chromatography and the degree of regioregularity by {sup 1}H RMN. P3HT/PS and P3HT/PMMA thin films were prepared by spin-coating technique from toluene solution at different P3HT concentrations. The doped films were obtained by immersion during 30 s in a 0.3 M ferric chloride (FeCl{sub 3}) solution in nitromethane. A classical percolation phenomenon was observed in the electrical properties of the binary blends, it was smaller than 4 wt.% of P3HT in the blend. Atomic force microscopy and confocal microscopy showed a phase-separated morphology. Variation in the surface morphology of the blends was observed, which was a function of the polymer concentration and the type of insulator polymer used in the blends. The insulator polymer was segregated on the surface of the films and showed pit and island-like topography. The pit and island size changed as a function of the polymer concentration. Optical absorption properties as a function of the P3HT concentration in the undoped and doped state were analyzed. In doped state, the bipolaron bands in the PS/P3HT and PMMA/P3HT blends were observed from a P3HT concentration of 1 wt.% and 3 wt.%, respectively. Finally, the polymers were analyzed by thermogravimetric analysis and infrared spectroscopy.

  15. Synthesis of PMMA-b-PU-b-PMMA tri-block copolymers through ARGET ATRP in the presence of air

    Directory of Open Access Journals (Sweden)

    P. Krol

    2013-03-01

    Full Text Available ARGET (activators regenerated by electron transfer ATRP (atom transfer radical polymerization has been successfully performed (in flasks fitted with rubber septa without the need for use of Schlenk line in the presence of limited amount of air and with a very small (370 ppm amount of copper catalyst together with an appropriate reducing agent Cu(0. Novelty of this work is that the poly(methyl methacrylate-block-polyurethane-block-poly(methyl methacrylate triblock copolymers were synthesized for the first time through ARGET ATRP, by using tertiary bromine-terminated polyurethane as a macroinitiator (MBP-PU-MBP, CuBr2 or CuCl2 as a catalyst and N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA or 2,2'-bipyridine (Bpy as a complexing agent. As the polymerization time increases, both the monomer conversion and ln([M]0/[M] increased and the molecular weight of copolymer increases linearly with increasing conversion. Theoretical number-average molecular weight (Mn, th of the tri-block copolymers was found to be comparable with number-average molecular weight determined by GPC analyses (Mn, GPC. These results indicate that the formation of the tri-block copolymers was through atom transfer radical polymerization mechanism. 1H and 13C NMR spectral methods were employed to confirm chemical structures of synthesized macroinitiator and tri-block copolymers. Mole percentage of PMMA in the tri-block copolymers was calculated using 1H NMR spectroscopy and was found to be comparable with the GPC results. Additionally, the studies of surface properties (confocal microscopy and SFE of tri-block copolymer coatings confirmed the presence of MMA segments.

  16. Effect of particle structure and surface chemistry on PMMA adsorption to silica nanoparticles.

    Science.gov (United States)

    Madathingal, Rajesh Raman; Wunder, Stephanie L

    2010-04-06

    The interphase layer of polymers adsorbed to silica surfaces can be affected by the surface silanol density as well as the relative size of the polymer compared with the size of the adsorbing substrate. Here, the nonequilibrium adsorption of PMMA onto individual colloidal Stober silica (SiO(2)) particles, where R(particle) (100 nm) > R(PMMA) (approximately 6.5 nm) was compared with the adsorption onto fumed silica, where R(particle) (7 nm) approximately R(PMMA) (6.5 nm) bonded to the silanols, and was independent of particle morphology. For methylated silica, (CH(3))(3)SiO(2), the adsorption isotherms were identical for colloidal and fumed silica, but T(g) was depressed for the former, and comparable to the bulk value for the latter. The increased T(g) of PMMA adsorbed onto fumed (CH(3))(3)SiO(2) was attributed to the larger loops formed by the bridging PMMA chains between the silica aggregates.

  17. Directed self-assembly of PS-b-PMMA with ionic liquid addition

    Science.gov (United States)

    Chen, Xuanxuan; Seo, Takehito; Rincon-Delgadillo, Paulina; Matsumiya, Tasuku; Kawaue, Akiya; Maehashi, Takaya; Gronheid, Roel; Nealey, Paul F.

    2016-03-01

    Directed self-assembly of block copolymers is a promising candidate to address grand challenges towards new generations of low-cost, high-resolution nanopatterning technology. Over the past decade, poly(styrene-b-methyl methacrylate) (PS-b-PMMA) has been the most popular block copolymer applied in this area. However, further scaling towards pitches below 20 nm is hindered by its relatively low segregation strength between constituent blocks, characterized by a low Flory-Huggins interaction parameter, χ (~ 0.038 at r.t). To reach sub-10 nm feature dimensions, many high- χ block copolymer materials and processes are currently being studied. Here we investigate the DSA of PSb- PMMA with blended ionic liquid (IL) on chemically-patterned substrates via thermal annealing with a free surface. In this materials system, by adding low volume fraction of IL, a substantially higher χ than the pure block copolymer is achieved with manageable change in surface and interfacial properties so that poly(styrene-random-methyl methacrylate) brushes may be used to control substrate wetting behavior, and the blend could be assembled using thermal annealing with a free surface. In other words, PS-b-PMMA/IL may serve as a high- χ drop-in replacement for PS-b-PMMA. In this work, we provide key DSA results to determine if PS-b-PMMA/IL blends would offer a solution for sub-10 nm lithography.

  18. Interphase and magnetotransport of LSMO-PMMA nanocomposites obtained by a sonochemical method

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Mariano [Centro NanoMat/Cryssmat Lab/Cátedra de Física – DETEMA – Facultad de Química – Universidad de la República (Uruguay); Centro Interdisciplinario de Nanotecnología, Química y Física de Materiales – Universidad de la República (Uruguay); Pardo, Helena, E-mail: hpardo@fq.edu.uy [Centro NanoMat/Cryssmat Lab/Cátedra de Física – DETEMA – Facultad de Química – Universidad de la República (Uruguay); Centro Interdisciplinario de Nanotecnología, Química y Física de Materiales – Universidad de la República (Uruguay); Faccio, Ricardo [Centro NanoMat/Cryssmat Lab/Cátedra de Física – DETEMA – Facultad de Química – Universidad de la República (Uruguay); Centro Interdisciplinario de Nanotecnología, Química y Física de Materiales – Universidad de la República (Uruguay); Tumelero, Milton A. [Laboratorio de filmes finos e superficies – Departamento de Física – Universidad Federal de Santa Catarina, Florianópolis (Brazil); and others

    2015-05-15

    In this report, we studied the structural, microstructural and compositional trends in a manganite-polymethylmethacrilate (LSMO-PMMA) nanocomposite prepared by a sonochemical method focusing in the study of its interphase and its correlation with magnetotransport. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Raman scattering and X-ray powder diffraction (XRPD) studies showed evidence of PMMA reactivity with partial decomposition at the LSMO nanoparticles interface. Additionally, grazing incidence small angle X-ray scattering (GISAXS) and high resolution transmission electron microscopy (HRTEM) showed information about the microstructure and the separation between nanoparticles in these nanocomposite materials. An enhancement in the low field magnetoresistance (LFMR) respect to pure LSMO was observed for a 20% weight fraction addition of PMMA in the high temperature regime (205–305 K) probably due to the increase in the magnetic disorder at the grain boundaries caused by the ultrasonic treatment. Nevertheless, lower PMMA weight fraction addition showed no enhancement in LFMR respect to pure LSMO, probably in agreement with the higher decomposition rate observed at the interphase. - Highlights: • We report the synthesis of LSMO-PMMA nanocomposites by a sonochemical method. • Compositional and microstructural trends were obtained from the interphase. • This method showed long-range homogeneity and enhancement of grain boundary disorder. • The enhancement on the LFMR respect to pure manganite was obtained at higher temperatures.

  19. A safe and cost-effective PMMA carbon source for MgB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Ranot, Mahipal; Shinde, K. P.; Oh, Y. S.; Kang, S. H.; Chung, K. C. [Korea Institute of Materials Science, Changwon (Korea, Republic of); Jang, S. H. [Kiswire Advanced Technology Ltd, Daejeon (Korea, Republic of); Sinha, B. B. [National Centre for Nanoscience and Nanotechnology, University of Mumbai, Mumbai (India); Bhardwaj, A. [Dept. of Physics, Sungkyunkwan University, Suwon (Korea, Republic of)

    2017-03-15

    Carbon is proven to be very effective in pinning the magnetic vortices and improving the superconducting performance of MgB2 at high fields. In this work, we have used polymethyl methacrylate (PMMA) polymer as a safe and cost effective carbon source. The effects of molecular weight of PMMA on crystal structure, microstructure as well as on superconducting properties of MgB2 were studied. X-ray diffraction analysis revealed that there is a noticeable shift in (100) and (110) Bragg reflections towards higher angles, while no shift was observed in (002) reflections for MgB2 doped with different molecular weights of PMMA. This indicates that carbon could be substituted in the boron honeycomb layers without affecting the interlayer interactions. As compared to undoped MgB2, substantial enhancement in Jc(H) properties was obtained for PMMA-doped MgB2 samples both at 5 K and 20 K. The enhancement could be attributed to the effective carbon substitution for boron and the refinement of crystallite size by PMMA doping.

  20. Comparing polyelectrolyte multilayer-coated PMMA microfluidic devices and glass microchips for electrophoretic separations.

    Science.gov (United States)

    Currie, Christa A; Shim, Joon Sub; Lee, Se Hwan; Ahn, Chong; Limbach, Patrick A; Halsall, H Brian; Heineman, William R

    2009-12-01

    There is a continuing drive in microfluidics to transfer microchip systems from the more expensive glass microchips to cheaper polymer microchips. Here, we investigate using polyelectrolyte multilayers (PEM) as a coating system for PMMA microchips to improve their functionality. The multilayer system was prepared by layer-to-layer deposition of poly(diallyldimethylammonium) chloride and polystyrene sulfonate. Practical aspects of coating PMMA microchips were explored. The multilayer buildup process was monitored using EOF measurements, and the stability of the PEM was investigated. The performance of the PEM-PMMA microchip was compared with those of a standard glass microchip and a PEM-glass microchip in terms of EOF and separating two fluorescent dyes. Several key findings in the development of the multilayer coating procedure for PMMA chips are also presented. It was found that, with careful preparation, a PEM-PMMA microchip can be prepared that has properties comparable--and in some cases superior--to those of a standard glass microchip.

  1. Thin Coatings of Polymeric Carbon and Carbon Nanotubes for Corrosion Protection

    Science.gov (United States)

    2009-02-01

    Carbon Nanotube Functionalization /Doping Polyvinylpyrrolidone (PVP) A) p-Doping C) Polymer Wrapping Model B) n-Doping Polyethyleneimine ( PEI ) SWCNT Paint...fluorine-containing) groups functions as the barrier layer Multilayer Smart Carbon Nanotube Coating Insoluble polymer layer top coating -PMMA Substrate...Thin Coatings of Polymeric Carbon and Carbon Nanotubes for Corrosion Protection Zafar Iqbal Department of Chemistry and Environmental Science New

  2. Microgravity Flammability of PMMA Rods in Concurrent Flow

    Science.gov (United States)

    Olson, Sandra L.; Ferkul, Paul V.

    2015-01-01

    Microgravity experiments burning cast PMMA cylindrical rods in axial flow have been conducted aboard the International Space Station in the Microgravity Science Glovebox (MSG) facility using the Burning and Suppression of Solids (BASS) flow duct, as part of the BASS-II experiment. Twenty-four concurrent-flow tests were performed, focusing on finding flammability limits as a function of oxygen and flow speed. The oxygen was varied by using gaseous nitrogen to vitiate the working volume of the MSG. The speed of the flow parallel to the rod was varied using a fan at the entrance to the duct. Both blowoff and quenching limits were obtained at several oxygen concentrations. Each experiment ignited the rod at the initially hemispherical stagnation tip of the rod, and allowed the flame to develop and heat the rod at a sufficient flow to sustain burning. For blowoff limit tests, the astronaut quickly turned up the flow to obtain extinction. Complementary 5.18-second Zero Gravity Facility drop tests were conducted to compare blowoff limits in short and long duration microgravity. For quenching tests, the flow was incrementally turned down and the flame allowed to stabilize at the new flow condition for at least the solid-phase response time before changing it again. Quenching was observed when the flow became sufficiently weak that the flame could no longer provide adequate heat flux to compensate for the heat losses (conduction into the rod and radiation). A surface energy balance is presented that shows the surface radiative loss exceeds the conductive loss into the rod near the limit. The flammability boundary is shown to represent a critical Damkohler number, expressed in terms of the reaction rate divided by the stretch rate. For the blowoff branch, the boundary exhibits a linear dependence on oxygen concentration and stretch rate, indicating that the temperature at blowoff must be fairly constant. For the quenching branch, the dominance of the exponential nature of

  3. Photophysical properties of fluorescent PMMA/SiO{sub 2} nanohybrids for solar energy applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Bashir, S.M., E-mail: elbashireg@yahoo.com [Department of Physics and Astronomy, Science College, King Saud University, Riyadh 11451 (Saudi Arabia)

    2012-07-15

    This work concerning the photophysical properties of fluorescent nanohybrid films based on poly(methylmethacrylate) (PMMA) doped with coumarin dyestuff and entrapped with different concentrations of hydrophilic nanosilica. Spectroscopic tools were applied in order to determine the optimum concentration of nanosilica for the best optical properties for a matrix used as fluorescent solar concentrator. The optical constants and photoluminescence spectra of fluorescent nanohybrid films showed an enhancement of the photon trapping efficiency and matrix stability by increasing the concentration of SiO{sub 2} nanoparticles. - Highlights: Black-Right-Pointing-Pointer Fluorescent PMMA/SiO{sub 2} nanohybrids were prepared and studied. Black-Right-Pointing-Pointer Adding small amounts of hydrophilic SiO{sub 2} nanoparticles to PMMA enhances its optical properties. Black-Right-Pointing-Pointer These hybrids are promising matrices for luminescent solar concentrators (LSCs).

  4. PMMA/PS coaxial electrospinning: core–shell fiber morphology as a function of material parameters

    Science.gov (United States)

    Rahmani, Shahrzad; Arefazar, Ahmad; Latifi, Masoud

    2017-03-01

    Core–shell fibers of polymethyl methacrylate (PMMA) and polystyrene (PS) have been successfully electrospun by coaxial electrospinning. To evaluate the influence of the solvent on the final fiber morphology, four types of organic solvents were used in the shell solution while the core solvent was preserved. Morphological observations with scanning electron microscopy, transmission electron microscopy and optical microscopy revealed that both core and shell solvent properties were involved in the final fiber morphology. To explain this involvement, alongside a discussion of the Bagley solubility graph of PS and PMMA, a novel criterion based on solvent physical properties was introduced. A theoretical model based on the momentum conservation principle was developed and applied for describing the dependence of the core and shell diameters to their solvent combinations. Different concentrations of core and shell were also investigated in the coaxial electrospinning of PMMA/PS. The core–shell fiber morphologies with different core and shell concentrations were compared with their single electrospun fibers.

  5. Infrared refractive index dispersion of PMMA spheres from synchrotron extinction spectra

    CERN Document Server

    Blümel, R; Lukacs, R; Kohler, A

    2016-01-01

    We performed high-resolution Fourier-transform infrared (FTIR) spectroscopy of a polymethyl methacrylate (PMMA) sphere of unknown size in the Mie scattering region. Apart from a slow, oscillatory structure (wiggles), which is due to an interference effect, the measured FTIR extinction spectrum exhibits a ripple structure, which is due to electromagnetic resonances. We fully characterize the underlying electromagnetic mode structure of the spectrum by assigning two mode numbers to each of the ripples in the measured spectrum. We show that analyzing the ripple structure in the spectrum in the wavenumber region from about $3000\\,$cm$^{-1}$ to $8000\\,$cm$^{-1}$ allows us to both determine the unknown radius of the sphere and the PMMA index of refraction, which shows a strong frequency dependence in this near-infrared spectral region. While in this paper we focus on examining a PMMA sphere as an example, our method of determining the refractive index and its dispersion from synchrotron infrared extinction spectra ...

  6. [The growth behavior of mouse fibroblasts on intraocular lens surface of various silicone and PMMA materials].

    Science.gov (United States)

    Kammann, J; Kreiner, C F; Kaden, P

    1994-08-01

    Experience with intraocular lenses (IOL) made of PMMA dates back ca. 40 years, while silicone IOLs have been in use for only about 10 years. The biocompatibility of PMMA and silicone caoutchouc was tested in a comparative study investigating the growth of mouse fibroblasts on different IOL materials. Spectrophotometric determination of protein synthesis and liquid scintillation counting of DNA synthesis were carried out. The spreading of cells was planimetrically determined, and the DNA synthesis of individual cells in direct contact with the test sample was tested. The results showed that the biocompatibility of silicone lenses made of purified caoutchouc is comparable with that of PMMA lenses; there is no statistically significant difference. However, impurities arising during material synthesis result in a statistically significant inhibition of cell growth on the IOL surfaces.

  7. Graphene transport properties upon exposure to PMMA processing and heat treatments

    DEFF Research Database (Denmark)

    Gammelgaard, Lene; Caridad, Jose; Cagliani, Alberto

    2014-01-01

    , allowing us to measure the evolution of the electrical transport properties during individual processing steps from the initial as-exfoliated to the PMMA-processed graphene. Heating generally promotes the conformation of graphene to SiO2 and is found to play a major role for the electrical properties......The evolution of graphene's electrical transport properties due to processing with the polymer polymethyl methacrylate (PMMA) and heat are examined in this study. The use of stencil (shadow mask) lithography enables fabrication of graphene devices without the usage of polymers, chemicals or heat...... of graphene while PMMA residues are found to be surprisingly benign. In accordance with this picture, graphene devices with initially high carrier mobility tend to suffer a decrease in carrier mobility, while in contrast an improvement is observed for low carrier mobility devices. We explain this by noting...

  8. An experimental method of measuring the quasi-static and dynamic confined behaviour of PMMA

    Directory of Open Access Journals (Sweden)

    Siad L.

    2010-06-01

    Full Text Available A testing device is presented for the experimental study of the confined behaviour of PMMA in compression under quasi-static loading or at high strain-rates. The constitutive relation of the material ring (allowing to confine the PMMA being known, transverse gauges glued on its lateral surface allow for the measurement of the lateral confining pressure. The hydrostatic pressure and the Mises stress may be computed. Quasi-static and dynamic tests performed in a strain-rate range of 1e-3/s 1e3/s are processed with the method and compared to results of unconfined compression tests. It is found that the compressive behaviour of PMMA is weakly influenced by the level of pressure and much more sensitive to strain-rate: an elastic brittle behaviour is observed at high strain-rates in unconfined or confined conditions whereas elastoplastic behaviour is noted under quasi-static loading.

  9. Antibacterial Properties of Tough and Strong Electrospun PMMA/PEO Fiber Mats Filled with Lanasol—A Naturally Occurring Brominated Substance

    Directory of Open Access Journals (Sweden)

    Richard L. Andersson

    2014-09-01

    Full Text Available A new type of antimicrobial, biocompatible and toughness enhanced ultra-thin fiber mats for biomedical applications is presented. The tough and porous fiber mats were obtained by electrospinning solution-blended poly (methyl methacrylate (PMMA and polyethylene oxide (PEO, filled with up to 25 wt % of Lanasol—a naturally occurring brominated cyclic compound that can be extracted from red sea algae. Antibacterial effectiveness was tested following the industrial Standard JIS L 1902 and under agitated medium (ASTM E2149. Even at the lowest concentrations of Lanasol, 4 wt %, a significant bactericidal effect was seen with a 4-log (99.99% reduction in bacterial viability against S. aureus, which is one of the leading causes of hospital-acquired (nosocomial infections in the world. The mechanical fiber toughness was insignificantly altered up to the maximum Lanasol concentration tested, and was for all fiber mats orders of magnitudes higher than electrospun fibers based on solely PMMA. This antimicrobial fiber system, relying on a dissolved antimicrobial agent (demonstrated by X-ray diffraction and Infrared (IR-spectroscopy rather than a dispersed and “mixed-in” solid antibacterial particle phase, presents a new concept which opens the door to tougher, stronger and more ductile antimicrobial fibers.

  10. Preventive effects of a phospholipid polymer coating on PMMA on biofilm formation by oral streptococci

    Science.gov (United States)

    Shibata, Yukie; Yamashita, Yoshihisa; Tsuru, Kanji; Ishihara, Kazuhiko; Fukazawa, Kyoko; Ishikawa, Kunio

    2016-12-01

    The regulation of biofilm formation on dental materials such as denture bases is key to oral health. Recently, a biocompatible phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) coating, was reported to inhibit sucrose-dependent biofilm formation by Streptococcus mutans, a cariogenic bacterium, on the surface of poly(methyl methacrylate) (PMMA) denture bases. However, S. mutans is a minor component of the oral microbiome and does not play an important role in biofilm formation in the absence of sucrose. Other, more predominant oral streptococci must play an indispensable role in sucrose-independent biofilm formation. In the present study, the effect of PMB coating on PMMA was evaluated using various oral streptococci that are known to be initial colonizers during biofilm formation on tooth surfaces. PMB coating on PMMA drastically reduced sucrose-dependent tight biofilm formation by two cariogenic bacteria (S. mutans and Streptococcus sobrinus), among seven tested oral streptococci, as described previously [N. Takahashi, F. Iwasa, Y. Inoue, H. Morisaki, K. Ishihara, K. Baba, J. Prosthet. Dent. 112 (2014) 194-203]. Streptococci other than S. mutans and S. sobrinus did not exhibit tight biofilm formation even in the presence of sucrose. On the other hand, all seven species of oral streptococci exhibited distinctly reduced glucose-dependent soft biofilm retention on PMB-coated PMMA. We conclude that PMB coating on PMMA surfaces inhibits biofilm attachment by initial colonizer oral streptococci, even in the absence of sucrose, indicating that PMB coating may help maintain clean conditions on PMMA surfaces in the oral cavity.

  11. PMMA mPOF Bragg gratings written in less than 10 min

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Nielsen, Kristian; Markos, Christos;

    2014-01-01

    Fiber Bragg grating (FBG) writing in PMMA microstructured Polymer Optical Fibers (mPOFs) using the UV Phase Mask technique is a time consuming process requiring about 40 minutes to inscribe a grating in an undoped fiber. Here we demonstrate the FBG inscription with the writing times shorter than 10...... min. By careful alligning and increasing the beam intensity in the core of the fiber, writing times as short as 6 minutes and 50 second were achieved. The FBGs were written in a 125 μm PMMA mPOF having 3-rings of holes, the reflection peaks were centred at 632.6 nm and have a reflectivity as high...

  12. Thermal response of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends

    Science.gov (United States)

    Mathur, Vishal; Sharma, Kananbala

    2016-02-01

    The present paper reports the investigationsto evaluate thermal behavior of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends, prepared at different compositions through solution casting method. The glass transition temperatures have been obtained using dynamic mechanical analyzer. Simultaneous measurements of temperature dependentthermal transport properties (thermal conductivity and thermal diffusivity) have been made using Hot Disk Thermal Constants Analyzer based on transient plane source. The study reveals that blending of PS with PMMA leads to different phase morphologies corresponding to different composition range which further affects the thermal performance of respective blends.

  13. Synthesis of novel chalcone derivatives and their stabilization effect of spiropyran in PMMA films

    Institute of Scientific and Technical Information of China (English)

    Zheng Kai Si; Qing Zhang; Min Zhao Xue; Yuan Yuan Zhu; Liang Ming; Qiao Rong Sheng; Yan Gang Liu

    2011-01-01

    Three novel bis-chalcone derivatives with different alkyldioxy spacers were synthesized and dispersed into polymethyl methacrylate (PMMA) chloroform solution with 6-nitro-1'-ethyl-3',3'-dimethylspiro-2H-1-benzopyran-2,2'-indoline (ESP) to prepare photochromic PMMA films in a facile way. After irradiation with 365 nm UV light, the photocrosslinking reaction between chalcone units was proved to retard the decolorization of merocyanine form of the photochromic spiropyran effectively, as results of the steric hindrance produced by photocycloaddition of chalcone groups. It has been found that the bis-chalcone molecule with the shortest spacer has the most effective stabilizing effect on retardation of decoloration of spiropyran.

  14. Bragg grating writing in PMMA microstructured polymer optical fibers in less than 7 minutes

    DEFF Research Database (Denmark)

    Bundalo, Ivan-Lazar; Nielsen, Kristian; Markos, Christos;

    2014-01-01

    We demonstrate fiber Bragg grating (FBG) writing in PMMA microstructured Polymer Optical Fibers (mPOFs) using UV Phase Mask technique with writing times shorter than 10 min. The shortest writing time was 6 minutes and 50 seconds and the longest writing time was 8 min and 50 sec. The FBGs were...... written in a 125 x00B5;m PMMA mPOF having 3-rings of holes, the reflection peaks were centred at 632.6 nm and have a reflectivity as high as 26 dB. We also demonstrate how the writing dynamics depends on the intensity of the writing beam....

  15. Surface Modification of SiC Nanoparticles with PMMA by Low Temperature Plasma

    Institute of Scientific and Technical Information of China (English)

    WEI Gang; ZHONG Shaofeng; MENG Yuedong; SHU Xingsheng

    2007-01-01

    An investigation into Poly (methyl methacrylate) (PMMA) grafted onto nano-SiC particles is reported in this study. In our experiment, the grafting polymerization reaction is induced by radio frequency (RF) discharge of N2 plasma treatment of the nanosized powder. FTIR (Fourier transform infrared spectrum), XPS (X-ray photoelectron spectroscopy) and TGA (Thermogravimetric analysis) results reveal that PMMA is grafted onto the surface of silicon carbide powder, and the crystal structure of the silicon carbide powder observed with XRD (X-ray diffraction) spectra is unchanged before and after the plasma graft polymerization.

  16. Thermal response of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends

    Science.gov (United States)

    Mathur, Vishal; Sharma, Kananbala

    2016-12-01

    The present paper reports the investigationsto evaluate thermal behavior of polystyrene/poly methyl methacrylate (PS/PMMA) polymeric blends, prepared at different compositions through solution casting method. The glass transition temperatures have been obtained using dynamic mechanical analyzer. Simultaneous measurements of temperature dependentthermal transport properties (thermal conductivity and thermal diffusivity) have been made using Hot Disk Thermal Constants Analyzer based on transient plane source. The study reveals that blending of PS with PMMA leads to different phase morphologies corresponding to different composition range which further affects the thermal performance of respective blends.

  17. Dielectric behavior of different nanofillers incorporated in PVC-PMMA based polymer electrolyte membranes

    Science.gov (United States)

    Sowmya, G.; Pradeepa, P.; Kalaiselvimary, J.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-01

    The Poly (methyl methacrylate) (PMMA)-Poly (vinyl chloride) (PVC) based polymer electrolytes were prepared by solvent casting technique. The prepared polymer electrolytes were subjected to conductivity studies by using electrochemical impedance spectroscopy and the maximum ionic conductivity value was found to be 0.8011 × 10-3 Scm-1 at 303K for PVC (17.5wt%) - PMMA (7.5wt %) - LiClO4 (8wt %) - PC (67wt %) - BaTiO3 (8wt%) electrolyte system. The dielectric behavior of the samples also studied.

  18. Synthesis and characterization of PMMA/clay nanocomposites prepared by in situ polymerization assisted by sonication; Sintese e caracterizacao de nanocompositos de PMMA/MMTO via polimerizacao in situ assistida por ultrassom

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Bruna R.; Bartoli, Julio R., E-mail: bartoli@unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil); Ito, Edson N. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2013-07-01

    In this work is presented the synthesis of nanocomposites of poly(methyl methacrylate), PMMA, with organically montmorillonite (OMMT) modified clays by in situ polymerization assisted by sonication. A statistically designed experiment was used, central composing design (CCD), to study the effect of synthesis variables on the dispersion of nanoparticles in PMMA matrix. The processing and formulation factors studied were: energy of sonication and Flory-Huggins interaction parameter between PMMA and organoclay. The structural (XRD) and morphological (TEM) characterizations of the PMMA/OMMT nanocomposites are compared with the literature. It was observed significant exfoliation of OMMT modified with hydroxyl groups in the nanocomposites of PMMA, mainly at the low ultrasonic energy level (90 and 105 kJ) studied. (author)

  19. Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin.

    Science.gov (United States)

    Mendonça e Bertolini, Martinna de; Cavalcanti, Yuri Wanderley; Bordin, Dimorvan; Silva, Wander José da; Cury, Altair Antoninha Del Bel

    2014-01-01

    The effect of Candida albicans biofilms and methyl methacrylate (MMA) pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA) resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based), and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10) were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR) and scanning electron microscopy (SEM) analysis were performed on denture liners (n = 8). Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

  20. Microfluidic DNA microarrays in PMMA chips: streamlined fabrication via simultaneous DNA immobilization and bonding activation by brief UV exposure

    DEFF Research Database (Denmark)

    Sabourin, David; Petersen, J; Snakenborg, Detlef

    2010-01-01

    This report presents and describes a simple and scalable method for producing functional DNA microarrays within enclosed polymeric, PMMA, microfluidic devices. Brief (30 s) exposure to UV simultaneously immobilized poly(T)poly(C)-tagged DNA probes to the surface of unmodified PMMA and activated t...

  1. Microfluidic DNA microarrays in PMMA chips: streamlined fabrication via simultaneous DNA immobilization and bonding activation by brief UV exposure

    DEFF Research Database (Denmark)

    Sabourin, David; Petersen, J; Snakenborg, Detlef

    2010-01-01

    This report presents and describes a simple and scalable method for producing functional DNA microarrays within enclosed polymeric, PMMA, microfluidic devices. Brief (30 s) exposure to UV simultaneously immobilized poly(T)poly(C)-tagged DNA probes to the surface of unmodified PMMA and activated t...

  2. Candida albicans biofilms and MMA surface treatment influence the adhesion of soft denture liners to PMMA resin

    Directory of Open Access Journals (Sweden)

    Martinna de Mendonça e Bertolini

    2014-01-01

    Full Text Available The effect of Candida albicans biofilms and methyl methacrylate (MMA pretreatment on the bond strength between soft denture liners and polymethyl methacrylate (PMMA resin was analyzed. Specimens were prepared and randomly divided with respect to PMMA pretreatment, soft liner type (silicone-based or PMMA-based, and presence or absence of a C. albicans biofilm. Samples were composed of a soft denture liner bonded between two PMMA bars. Specimens (n = 10 were incubated to produce a C. albicans biofilm or stored in sterile PBS for 12 days. The tensile bond strength test was performed and failure type was determined using a stereomicroscope. Surface roughness (SR and scanning electron microscopy (SEM analysis were performed on denture liners (n = 8. Highest bond strength was observed in samples containing a silicone-based soft liner and stored in PBS, regardless of pretreatment (p < 0.01. Silicone-based specimens mostly underwent adhesive failures, while samples containing PMMA-based liners predominantly underwent cohesive failures. The silicone-based specimens SR decreased after 12 days of biofilm accumulation or PBS storage, while the SR of PMMA-based soft liners increased (p < 0.01. The PMMA-based soft liners surfaces presented sharp valleys and depressions, while silicone-based specimens surfaces exhibited more gentle features. In vitro exposure to C. albicans biofilms reduced the adhesion of denture liners to PMMA resin, and MMA pretreatment is recommended during relining procedures.

  3. 静电纺丝制备PMMA/PVDF锂离子电池隔膜%Preparation of PMMA/PVDF lithium ion battery separator by electrospinning

    Institute of Scientific and Technical Information of China (English)

    胥会; 陈建; 代文超; 罗少伶

    2016-01-01

    利用电纺法制备了聚偏氟乙烯(PVDF)以及PVDF/聚甲基丙烯酸甲酯(PMMA)纳米纤维膜,用扫描电镜、红外光谱和热重等手段对纤维膜进行结构和性能表征,并测定了膜的孔隙率和吸液率.结果表明:当电压为20kV,接受距离为16cm,纺丝速率为0.001mm/s时,纺丝浓度为12%(质量分数),得到的纤维形貌较好.混合纺时PMMA加入没有改变PVDF原有的结构,复合隔膜的耐热温度达到470℃.PMMA/PVDF复合隔膜的吸液率和孔隙率整体提高且远远大于商业隔膜,其中PMMA/PVDF(4∶6)隔膜的吸液率和孔隙率分别达637%、67%,为最优.

  4. Fabrication Of Porous Ti By Thermal Decomposition And Sintering Of PMMA/TiH2 Powder Compact

    Directory of Open Access Journals (Sweden)

    Jeon K.Ch.

    2015-06-01

    Full Text Available Porous Ti with controlled pore structure was fabricated by thermal decomposition and sintering process using TiH2 powders and Polymethylmethacrylates (PMMA beads as pore forming agent. The beads sizes of 8 and 50 μm were used as a template for fabricating the porous Ti. The TiH2 powder compacts with 20 and 70 vol% PMMA were prepared by uniaxial pressing and sintered for 2 h at 1100°C. TGA analysis revealed that the PMMA and TiH2 were thermally decomposed at about 400°C forming pores and at about 600°C into metallic Ti phase. The porosity increased with increase in the amount of PMMA addition. Also, the microstructure observation showed that the pore size and shape were strongly dependent on the PMMA shapes.

  5. Fabrication of rectangular cross-sectional microchannels on PMMA with a CO2 laser and underwater fabricated copper mask

    Science.gov (United States)

    Prakash, Shashi; Kumar, Subrata

    2017-09-01

    CO2 lasers are commonly used for fabricating polymer based microfluidic devices. Despite several key advantages like low cost, time effectiveness, easy to operate and no requirement of clean room facility, CO2 lasers suffer from few disadvantages like thermal bulging, improper dimensional control, difficulty to produce microchannels of other than Gaussian cross sectional shapes and inclined surface walls. Many microfluidic devices require square or rectangular cross-sections which are difficult to produce using normal CO2 laser procedures. In this work, a thin copper sheet of 40 μm was used as a mask above the PMMA (Polymethyl-methacrylate) substrate while fabricating the microchannels utilizing the raster scanning feature of the CO2 lasers. Microchannels with different width dimensions were fabricated utilizing a CO2 laser in with mask and without-mask conditions. A comparison of both the fabricating process has been made. It was found that microchannels with U shape cross section and rectangular cross-section can efficiently be produced using the with mask technique. In addition to this, this technique can provide perfect dimensional control and better surface quality of the microchannel walls. Such a microchannel fabrication process do not require any post-processing. The fabrication of mask using a nanosecond fiber laser has been discussed in details. An underwater laser fabrication method was adopted to overcome heat related defects in mask preparation. Overall, the technique was found to be easy to adopt and significant improvements were observed in microchannel fabrication.

  6. Studies on thin film materials on acrylics for optical applications

    Indian Academy of Sciences (India)

    K Narasimha Rao

    2003-02-01

    Deposition of durable thin film coatings by vacuum evaporation on acrylic substrates for optical applications is a challenging job. Films crack upon deposition due to internal stresses and leads to performance degradation. In this investigation, we report the preparation and characterization of single and multi-layer films of TiO2, CeO2, Substance2 (E Merck, Germany), Al2O3, SiO2 and MgF2 by electron beam evaporation on both glass and PMMA substrates. Optical micrographs taken on single layer films deposited on PMMA substrates did not reveal any cracks. Cracks in films were observed on PMMA substrates when the substrate temperature exceeded 80°C. Antireflection coatings of 3 and 4 layers have been deposited and characterized. Antireflection coatings made on PMMA substrate using Substance2 (H2) and SiO2 combination showed very fine cracks when observed under microscope. Optical performance of the coatings has been explained with the help of optical micrographs.

  7. Enhanced bias stability of solution-processed zinc-tin-oxide thin film transistors using self-assembled monolayer as a selective channel passivation.

    Science.gov (United States)

    Heo, Jae-Sang; Park, Sung-Kyu

    2013-10-01

    The enhanced positive bias stability of amorphous zinc-tin-oxide thin-film transistors (a-ZTO TFTs) were obtained by applying self-assembled monolayer (SAM) as a selective passivation layer on the metal-oxide back channel area. The a-ZTO TFTs with passivation layers such as poly(methyl methacylate) (PMMA), SAM, and SAM/PMMA were fabricated by simple solution methods. After deposition of the passivation layers, the electrical characteristics of a-ZTO TFTs have not been changed and the threshold voltage shift (deltaV(th)) under gate-bias stress for around 10(4) seconds was improved. The deltaV(th) of the devices with PMMA, SAM, and SAM/PMMA dual layer were 3.79 V, 3.2 V, and 2.17 V, respectively.

  8. Optical properties (uv-vis and ftir) of gamma irradiated polymethyl methacrylate (pmma)

    CERN Document Server

    Rai, V N; Jain, Beena

    2016-01-01

    The effect of gamma irradiation on the UV-Vis and FTIR spectroscopy of polymethyl methacrylate (PMMA) foils has been studied. A new absorption band is observed in the visible spectral range due to color centers induced in the gamma irradiated PMMA. This band shows maximum absorption (low transmission) for 10 kGy irradiation, which decreases and saturates after 50 kGy followed by a further increase at 500 kGy. The FTIR peaks show an increased absorption up to ~100 kGy irradiation, which reverses for higher doses. Broad band absorption is observed in FTIR spectra around 1600 and 3600 cm-1 due to absorption of moisture in the irradiated samples. The reduction in the absorption intensity at 1718 cm-1 in the irradiated PMMA (> 100 kGy) is found associated with the demerization of the carbonyl groups. An initial increase in the absorption of FTIR peaks with increase in the doses of irradiation is due to increased cross linking in the PMMA structure that is induced by the absorption of moisture. The demerization of ...

  9. Time-dependent variation of fiber Bragg grating reflectivity in PMMA-based polymer optical fibers

    DEFF Research Database (Denmark)

    Saez-Rodriguez, D.; Nielsen, Kristian; Bang, Ole;

    2015-01-01

    In this Letter, we investigate the effects of viscoelasticity on both the strength and resonance wavelength of two fiber Bragg gratings (FBGs) inscribed in microstructured polymer optical fiber (mPOF) made of undoped PMMA. Both FBGs were inscribed under a strain of 1% in order to increase...

  10. Nano-imprint lithography using poly (methyl methacrylate) (PMMA) and polystyrene (PS) polymers

    Science.gov (United States)

    Ting, Yung-Chiang; Shy, Shyi-Long

    2016-04-01

    Nano-imprinting lithography (NIL) technology, as one of the most promising fabrication technologies, has been demonstrated to be a powerful tool for large-area replication up to wafer-level, with features down to nanometer scale. The cost of resists used for NIL is important for wafer-level large-area replication. This study aims to develop capabilities in patterning larger area structure using thermal NIL. The commercial available Poly (Methyl Methacrylate) (PMMA) and Polystyrene (PS) polymers possess a variety of characteristics desirable for NIL, such as low material cost, low bulkvolumetric shrinkage, high spin coating thickness uniformity, high process stability, and acceptable dry-etch resistance. PMMA materials have been utilized for positive electron beam lithography for many years, offering high resolution capability and wide process latitude. In addition, it is preferable to have a negative resist like PMMA, which is a simple polymer with low cost and practically unlimited shelf life, and can be dissolved easily using commercial available Propylene glycol methyl ether acetate (PGMEA) safer solvent to give the preferred film thickness. PS is such a resist, as it undergoes crosslinking when exposed to deep UV light or an electron beam and can be used for NIL. The result is a cost effective patterning larger area structure using thermal nano-imprint lithography (NIL) by using commercial available PMMA and PS ploymers as NIL resists.

  11. The effect of alumina nanofillers size and shape on mechanical behavior of PMMA matrix composite

    Directory of Open Access Journals (Sweden)

    Ben Hasan Somaya Ahmed

    2014-01-01

    Full Text Available Composites with the addition of alumina nanofillers show improvement in mechanical properties. The PMMA polymer was used as a matrix and two different types of nanofillers, having extremely different shapes were added in the matrix to form the composite. Reinforcements were based on alumina nanoparticles having either spherical shape or whiskers having the length to diameter ratio of 100. The influence of alumina fillers size, shape and fillers loading on mechanical properties of prepared composite were studied using the nanoindentation measurements and dynamic mechanical analysis. It was observed that both alumina whiskers and alumina spherical nanoparticles added in the PMMA matrix improved the mechanical properties of the composite but the improvement was significantly higher with alumina whisker reinforcement. The concentration of the reinforcing alumina spherical nanoparticles and alumina whiskers in PMMA matrix varied up to 5 wt. %. The best performance was obtained by the addition of 3 wt. % of alumina whiskers in the PMMA matrix with regard to mechanical properties of the obtained composite.

  12. Measuring the Dispersion Curve of a PMMA-Fibre Optic Cable Using a Dye Laser

    Science.gov (United States)

    Zorba, Serkan; Farah, Constantine; Pant, Ravi

    2010-01-01

    An advanced undergraduate laboratory experiment is outlined which uses a dye laser to map out the chromatic dispersion curve of a polymethyl methacrylate (PMMA) optical fibre. Seven different wavelengths across the visible spectrum are employed using five different dyes. The light pulse is split into two pulses, one to a nearby photodetector and…

  13. PMMA-N,N,N-trimethyl chitosan nanoparticles for fabrication of antibacterial natural rubber latex gloves.

    Science.gov (United States)

    Arpornwichanop, Thanida; Polpanich, Duangporn; Thiramanas, Raweewan; Suteewong, Teeraporn; Tangboriboonrat, Pramuan

    2014-08-30

    This paper presents one-pot synthesis of N,N,N-trimethyl chitosan (TMC) stabilized poly(methyl methacrylate) (PMMA) latex particles via the miniemulsion polymerization technique. From (1)H NMR, synthesized TMC contains 52% degree of quaternization. Compared to native biopolymer chitosan, TMC possesses permanently positive charges as well as provides greater antibacterial activity. Combining properties of PMMA and TMC, PMMA-TMC latex nanoparticles (hydrodynamic size ≈282 nm) could be used in place of inorganic lubricating powder in fabrication of latex gloves at pH ≥ 7. After immersing sulphur prevulcanized natural rubber (SPNR) film into 3 wt% of PMMA-TMC latex at pH 7, significant amount of nanoparticles uniformly deposited onto SPNR film was observed under SEM. A number of nanoparticles present on film surface would increase surface roughness of the rubber film and potentially inhibit the bacterial (Escherichia coli and Staphylococcus aureus) growth, which would be useful for fabrication of special gloves with antibacterial property.

  14. Rewritable 3D bit optical data storage in a PMMA-based photorefractive polymer

    Energy Technology Data Exchange (ETDEWEB)

    Day, D.; Gu, M. [Swinburne Univ. of Tech., Hawthorn, Vic. (Australia). Centre for Micro-Photonics; Smallridge, A. [Victoria Univ., Melbourne (Australia). School of Life Sciences and Technology

    2001-07-04

    A cheap, compact, and rewritable high-density optical data storage system for CD and DVD applications is presented by the authors. Continuous-wave illumination under two-photon excitation in a new poly(methylmethacrylate) (PMMA) based photorefractive polymer allows 3D bit storage of sub-Tbyte data. (orig.)

  15. The effect of enhancing the hydrophobicity of OMMT on the characteristics of PMMA/OMMT nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Yamagata, Shuichi, E-mail: shuic@den.hokudai.ac.jp [Department of Orthodontics, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Hamba, Yusuke [Department of Orthodontics, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Akasaka, Tsukasa [Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Ushijima, Natsumi [Support Section for Education and Research, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Uo, Motohiro [Advanced Biomaterials, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549 (Japan); Iida, Junichiro [Department of Orthodontics, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan); Watari, Fumio [Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo 060-8586 (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer PMMA/OMMT nanocomposites were fabricated using a solution intercalation method. Black-Right-Pointing-Pointer The silicate platelets were largely well dispersed independent of the hydrophobicity. Black-Right-Pointing-Pointer The partially exfoliation of the silicate layers were observed. Black-Right-Pointing-Pointer The flexural modulus of the nanocomposites increased favorably. Black-Right-Pointing-Pointer The strain at breakage of the nanocomposites remained suitable for our use. - Abstract: Transparent poly(methyl methacrylate)/organically modified montmorillonite (PMMA/OMMT) nanocomposites were fabricated using a solution intercalation method. Two grades of OMMT modified with quaternary alkylammonium ions and containing different amounts of organic matter, NZ70 and NX, were used. X-ray diffraction patterns showed that the peaks regarded as a (0 0 1) d-spacing and a second peak were shifted toward lower 2{theta} values, implying the expansion or the partial exfoliation of the silicate layers, respectively. TEM images showed that the silicate platelets were largely well dispersed independent of the hydrophobicity, although some aggregates were observed. The flexural modulus of the PMMA/OMMT nanocomposites increased favorably with an increasing amount of OMMT of either grade. However, only the NX displayed comparable strain at breakage to that of the PMMA. These results suggest that the highly hydrophobic grade NX shows great promise for use in nanocomposites made via solution intercalation.

  16. Porous asymmetric SiO2-g-PMMA nanoparticles produced by phase inversion

    KAUST Repository

    Munirasu, Selvaraj

    2014-07-22

    A new kind of asymmetric organic-inorganic porous structure has been proposed. Asymmetric lattices of polymer grafted silica nanoparticles were manufactured by casting and phase inversion in water. Silica nanoparticles were first functionalized with 3-(dimethylethoxysilyl)propyl-2-bromoisobutyrate, followed by grafting of poly(methylmethacrylate) (PMMA) segments, performed by atom-transfer radical polymerization. Mechanically stable self-standing films were prepared by casting a dispersion of functionalized nanoparticles in different solvents and immersion in water. The resulting asymmetrically porous morphology and nanoparticle assembly was characterized by scanning electron and atomic force microscopy. The PMMA functionalized SiO2 hybrid material in acetone or acetone/dioxane led to the best-assembled structures. Porous asymmetric membranes were prepared by adding free PMMA and PMMA terminated with hydrophilic hydroxyl group. Nitrogen flow of 2800 L m-2 h -1 was measured at 1.3 bar demonstrating the porosity and potential application for membrane technology. © 2014 Springer Science+Business Media New York.

  17. Hot embossing of electrophoresis microchannels in PMMA substrates using electric heating wires.

    Science.gov (United States)

    Gan, Zhibing; Yu, Zhengyin; Chen, Zhi; Chen, Gang

    2010-04-01

    A simple method based on electric heating wires has been developed for the rapid fabrication of poly(methyl methacrylate) (PMMA) electrophoresis microchips in ordinary laboratories without the need for microfabrication facilities. A piece of stretched electric heating wire placed across the length of a PMMA plate along its midline was sandwiched between two microscope slides under pressure. Subsequently, alternating current was allowed to pass through the wire to generate heat to emboss a separation microchannel on the PMMA separation channel plate at room temperature. The injection channel was fabricated using the same procedure on a PMMA sheet that was perpendicular to the separation channel. The complete microchip was obtained by bonding the separation channel plate to the injection channel sheet, sealing the channels inside. The electric heating wires used in this work not only generated heat; they also served as templates for embossing the microchannels. The prepared microfluidic microchips have been successfully employed in the electrophoresis separation and detection of ions in connection with contactless conductivity detection.

  18. Zeonex-PMMA microstructured polymer optical FBGs for simultaneous humidity and temperature sensing

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Pedersen, Jens Kristian Mølgaard; Fasano, Andrea

    2017-01-01

    In this Letter, we report for the first time, to the best of our knowledge, the fabrication and characterization of a Zeonex/PMMA microstructured polymer optical fiber (mPOF) Bragg grating sensor for simultaneous monitoring of relative humidity (RH) and temperature. The sensing element (probe...

  19. The Limits of Lamellae-Forming PS-b-PMMA Block Copolymers for Lithography.

    Science.gov (United States)

    Wan, Lei; Ruiz, Ricardo; Gao, He; Patel, Kanaiyalal C; Albrecht, Thomas R; Yin, Jian; Kim, Jihoon; Cao, Yi; Lin, Guanyang

    2015-07-28

    We explore the lithographic limits of lamellae-forming PS-b-PMMA block copolymers by performing directed self-assembly and pattern transfer on a range of PS-b-PMMA materials having a full pitch from 27 to 18.5 nm. While directed self-assembly on chemical contrast patterns was successful with all the materials used in this study, clean removal of PMMA domains and subsequent pattern transfer could only be sustained down to 22 nm full pitch. We attribute this limitation to the width of the interface, which may represent more than half of the domain width for materials with a critical dimension below 10 nm. With the limit of pattern transfer for PS-b-PMMA set at ∼11 nm, we propose an integration scheme suitable for bit patterned media for densities above 1.6 Tdot/in(2), which require features below this limit. Directed self-assembly was carried out on chemical contrast patterns made by a rotary e-beam lithography system, and pattern transfer was carried out to demonstrate fabrication of large area (up to 25 mm-wide annular band of circular tracks) nanoimprint templates for bit patterned media. We also demonstrate compatibility with hard disk drive architecture by fabricating patterns with skewed radial lines with constant angular pitch and with servo patterns that are needed in hard disk drives to generate a radial positional error signal (PES).

  20. Effect of gentamicin loaded PMMA bone cement on Staphylococcus aureus biofilm formation

    NARCIS (Netherlands)

    Poelstra, KA; Busscher, HJ; Schenk, W; van Horn, [No Value; van der Mei, HC

    1999-01-01

    PMMA (poly-methyl-methacrylate) bone cement is widely used in prosthetic implant surgery and is currently prepared with vacuum-mixing for improved mechanical properties. Revision of implants due to infection occurs in about 1% of cases, mostly involving staphylococcal strains. Antibiotic loaded ceme

  1. Clinical Observation of 126 Cases of Sutureless Phacoemulsification with PMMA Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    Yanshuang Yan; Zhengxing Mao

    2000-01-01

    Objective: To observe the safety and effect of sutureless phacoemulsification with PMMA intraocular lens (IOL) implantation.Methods: One-hundred and twenty-six cases (126 eyes) of sutureless phacoemulsification with PMMA intraocular lens (IOL) implantation were retrospected and evaluated. The surgeries were performed through a limbal tunnel incision. PMMA IOLs with 5.5mm or 6.0mm in diameter were implanted.Results: The follow-up was 3~20 months. Visual acuity of 0. 5 or better was obtained in 120 cases (95.2%), and that of 1.0 or better was obtained in 89 cases (70. 6% ).Intra-operative complications included posterior capsule rupture in 9 cases (7. 1% ) and iris injury in 7 cases(5.6% ). Postoperative complications included early corneal edema in 96 cases(76.2% ), transient intraocular pressure elevation in 5 cases(4. 3%),remnant of cortex in 1 case and leakage of incision in 1 case. M1 were properly managed with good results.Conclusion: Sutureless phacoemulsification with PMMA IOL implantation is safe even in grass-root hospitals where cataracts are harder.

  2. Surface morphology of PMMA/boehmite hybrid nanostructures prepared via facile one-pot process

    Science.gov (United States)

    Ghamari, Misagh; Farzi, Gholamali

    2017-08-01

    In this study, we developed the novel aqueous-based PMMA/AlOOH hybrid by a one-pot process starting from their relevant precursors in a controlled manner. Starting chemical reactions directly from precursors and the sequence of adding reactants provide the possibility towards enhancing the homogeneity of the final product. Inorganic and organic segments were made compatible by means of oleic acid as a coupling agent. Boehmite to PMMA weight ratio as the main parameter was varied from 0 to 18% and the morphology, particle size, size distribution, and topography map of hybrids was shown to be composition dependent. Final PMMA/Bo nanohybrids were characterized using FTIR to confirm the chemical interactions between inorganic and organic segments. TEM analysis showed that nanohybrid particles with irregular shapes containing inorganic particles dispersed in the organic matrix are formed with an average diameter which depends on boehmite content. The presence of phase transformation of Bo makes PMMA/Bo hybrids significantly thermally stable. According to AFM topography map analysis and relevant Gaussian fit function, the roughness of nanocomposite, the size of hybrid nanoparticles and deviation from the mean value (size) were increased as Bo increases from 0 to 18.

  3. New Concept of Polymethyl Methacrylate (PMMA and Polyethylene Terephthalate (PET Surface Coating by Chitosan

    Directory of Open Access Journals (Sweden)

    Mieszko Wieckiewicz

    2016-04-01

    Full Text Available Chitosan is known for its hemostatic and antimicrobial properties and might be useful for temporary coating of removable dentures or intraoral splints to control bleeding after oral surgery or as a supportive treatment in denture stomatitis. This study investigated a new method to adhere chitosan to polymethyl methacrylate (PMMA and polyethylene terephthalate (PET. There were 70 cylindrical specimens made from PMMA and 70 from PET (13 mm diameter, 6 mm thickness. The materials with ten specimens each were sandblasted at 2.8 or 4.0 bar with aluminum oxide 110 μm or/and aluminum oxide coated with silica. After sandblasting, all specimens were coated with a 2% or 4% acetic chitosan solution with a thickness of 1 mm. Then the specimens were dried for 120 min at 45 °C. The precipitated chitosan was neutralized with 1 mol NaOH. After neutralization, all specimens underwent abrasion tests using the tooth-brushing simulator with soft brushes (load 2N, 2 cycles/s, 32 °C, 3000 and 30,000 cycles. After each run, the specimen surfaces were analyzed for areas of remaining chitosan by digital planimetry under a light microscope. The best chitosan adhesion was found after sandblasting with aluminum oxide coated with silica (U-Test, p < 0.05 in both the PMMA and the PET groups. Hence, with relatively simple technology, a reliable bond of chitosan to PMMA and PET could be achieved.

  4. Physical and biological properties of the ion beam irradiated PMMA-based composite films

    Energy Technology Data Exchange (ETDEWEB)

    Shanthini, G.M.; Martin, Catherine Ann; Sakthivel, N.; Veerla, Sarath Chandra; Elayaraja, K. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Lakshmi, B.S. [Department of Biotechnology, Anna University, Chennai 600025 (India); Asokan, K.; Kanjilal, D. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kalkura, S. Narayana, E-mail: kalkurasn@annauniv.edu [Crystal Growth Centre, Anna University, Chennai 600025 (India)

    2015-02-28

    Highlights: • First report of swift heavy ion irradiation on PMMA-HAp as bioceramic composite. • Augmented protein adsorption of about 400% was attained due to irradiation. • Tailored surface morphology, topography, roughness, wettability and crystallinity. • Irradiation transformed the hydrophobic surface into hydrophilic surface. • Better blood and cell–material interaction leading to improved biocompatibility. - Abstract: Polymethyl methacrylate (PMMA) and PMMA-hydroxyapatite (PMMA-HAp) composite films, prepared by the solvent evaporation method were irradiated with 100 MeV Si{sup 7+} ions. Crystallographic, morphological and the functional groups of the pristine and irradiated samples were studied using glancing incident X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) respectively. SEM reveals the creation of pores, along with an increase in porosity and cluster size on irradiation. Decrease in crystalline nature and crystallite size with an increase in ion fluence was observed from GIXRD patterns. The surface roughness and the wettability of the material were also enhanced, which could favour the cell–material interaction. The irradiated samples adsorbed significantly greater amount of proteins than pristine. Also, irradiation does not produce any toxic byproducts or leachants, and maintains the viability of 3T3 cells. The response of the irradiated samples towards biomedical applications was demonstrated by the improved antimicrobial activity, haemocompatibility and cytocompatibility. Swift heavy ion irradiation (SHI) could be an effective tool to modify and engineer the surface properties of the polymers to enhance the biocompatibility.

  5. Effect of BaSO4 on the fatigue crack propagation rate of PMMA bone cement.

    Science.gov (United States)

    Molino, L N; Topoleski, L D

    1996-05-01

    To determine the effect of BaSO4 on the fatigue crack growth rate, da/dN = C(delta K)n, of poly(methyl methacrylate) (PMMA) bone cement, radiopaque bone cement, radiolucent bone cement, and commercial PMMA (Plexiglas) were tested using a methodology based on ASTM E647. The crack growth rate of radiopaque bone cement was one order of magnitude less than that of radiolucent. Fractographic analysis showed that the regions of rapid catastrophic fracture were smooth for all materials tested. The radiopaque fatigue surface was rough and characterized by ragged-edged stacked plateaus, a morphology consistent with the model of crack propagation through the interbead matrix. Voids were visible in the interbead matrix on the order of the size of BaSO4 particles. The fatigue surface of radiolucent bone cement was relatively smooth, a morphology consistent with crack propagation through both the PMMA beads and interbead matrix. Fatigue striations were visible, and their spacing correlated well with crack propagation rates. The striations indicated an increased crack growth rate through the PMMA beads.

  6. Measuring the Dispersion Curve of a PMMA-Fibre Optic Cable Using a Dye Laser

    Science.gov (United States)

    Zorba, Serkan; Farah, Constantine; Pant, Ravi

    2010-01-01

    An advanced undergraduate laboratory experiment is outlined which uses a dye laser to map out the chromatic dispersion curve of a polymethyl methacrylate (PMMA) optical fibre. Seven different wavelengths across the visible spectrum are employed using five different dyes. The light pulse is split into two pulses, one to a nearby photodetector and…

  7. Surface, electrical and mechanical modifications of PMMA after implantation with laser produced iron plasma ions

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Qazi Salman; Bashir, Shazia, E-mail: shaziabashir@gcu.edu.pk; Jalil, Sohail Abdul; Shabbir, Muhammad Kaif; Mahmood, Khaliq; Akram, Mahreen; Khalid, Ayesha; Yaseen, Nazish; Arshad, Atiqa

    2016-07-01

    Laser Produced Plasma (LPP) was employed as an ion source for the modifications in surface, electrical and mechanical properties of poly methyl (methacrylate) PMMA. For this purpose Nd:YAG laser (532 nm, 6 ns, 10 Hz) at a fluence of 12.7 J/cm{sup 2} was employed to generate Fe plasma. The fluence and energy measurements of laser produced Fe plasma ions were carried out by employing Thomson Parabola Technique in the presence of magnetic field strength of 0.5 T, using CR-39 as Solid State Nuclear Track Detector (SSNTD). It has been observed that ion fluence ejecting from ablated plasma was maximum at an angle of 5° with respect to the normal to the Fe target surface. PMMA substrates were irradiated with Fe ions of constant energy of 0.85 MeV at various ion fluences ranging from 3.8 × 10{sup 6} ions/cm{sup 2} to 1.8 × 10{sup 8} ions/cm{sup 2} controlled by varying laser pulses from 3000 to 7000. Optical microscope and Scanning Electron Microscope (SEM) were utilized for the analysis of surface features of irradiated PMMA. Results depicted the formation of chain scission, crosslinking, dendrites and star like structures. To explore the electrical behavior, four probe method was employed. The electrical conductivity of ion irradiated PMMA was increased with increasing ion fluence. The surface hardness was measured by shore D hardness tester and results showed the monotonous increment in surface hardness with increasing ion fluence. The increasing trend of surface hardness and electrical conductivity with increasing Fe ion fluence has been well correlated with the surface morphology of ion implanted PMMA. The temperature rise of PMMA surface due to Fe ion irradiation is evaluated analytically and comes out to be in the range of 1.72 × 10{sup 4} to 1.82 × 10{sup 4} K. The values of total Linear Energy Transfer (LET) or stopping power of 0.8 MeV Fe ions in PMMA is 61.8 eV/Å and their range is 1.34 μm evaluated by SRIM simulation.

  8. Thickness dependent CARS measurement of polymeric thin films without depth-profiling.

    Science.gov (United States)

    Choi, Dae Sik; Jeoung, Sae Chae; Chon, Byung-Hyuk

    2008-02-18

    Coherent anti-Stokes Raman scattering (CARS) microscopy is demonstrated to be a promising optical method for the characterization of polymer films with film thickness varying between 180 nm to 4300 nm. In case of PMMA films with a thickness of few hundreds of nanometers, the observed CARS signal was mainly associated with the interference effect of large nonresonant CARS field from glass substrate and the weak resonant field of PMMA. The dependence of resonant CARS intensity of PMMA film on film thickness is in good agreement with the theoretical prediction on a CARS field. The current work offers potential possibilities of noninvasive thickness measurement of polymeric thin film of thickness less than 180 nm by multiplex CARS microscopy without depth-profiling.

  9. Preparation of Transparent Bulk TiO2/PMMA Hybrids with Improved Refractive Indices via an in Situ Polymerization Process Using TiO2 Nanoparticles Bearing PMMA Chains Grown by Surface-Initiated Atom Transfer Radical Polymerization.

    Science.gov (United States)

    Maeda, Satoshi; Fujita, Masato; Idota, Naokazu; Matsukawa, Kimihiro; Sugahara, Yoshiyuki

    2016-12-21

    Transparent TiO2/PMMA hybrids with a thickness of 5 mm and improved refractive indices were prepared by in situ polymerization of methyl methacrylate (MMA) in the presence of TiO2 nanoparticles bearing poly(methyl methacrylate) (PMMA) chains grown using surface-initiated atom transfer radical polymerization (SI-ATRP), and the effect of the chain length of modified PMMA on the dispersibility of modified TiO2 nanoparticles in the bulk hybrids was investigated. The surfaces of TiO2 nanoparticles were modified with both m-(chloromethyl)phenylmethanoyloxymethylphosphonic acid bearing a terminal ATRP initiator and isodecyl phosphate with a high affinity for common organic solvents, leading to sufficient dispersibility of the surface-modified particles in toluene. Subsequently, SI-ATRP of MMA was achieved from the modified surfaces of the TiO2 nanoparticles without aggregation of the nanoparticles in toluene. The molecular weights of the PMMA chains cleaved from the modified TiO2 nanoparticles increased with increases in the prolonging of the polymerization period, and these exhibited a narrow distribution, indicating chain growth controlled by SI-ATRP. The nanoparticles bearing PMMA chains were well-dispersed in MMA regardless of the polymerization period. Bulk PMMA hybrids containing modified TiO2 nanoparticles with a thickness of 5 mm were prepared by in situ polymerization of the MMA dispersion. The transparency of the hybrids depended significantly on the chain length of the modified PMMA on the nanoparticles, because the modified PMMA of low molecular weight induced aggregation of the TiO2 nanoparticles during the in situ polymerization process. The refractive indices of the bulk hybrids could be controlled by adjusting the TiO2 content and could be increased up to 1.566 for 6.3 vol % TiO2 content (1.492 for pristine PMMA).

  10. Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

    Science.gov (United States)

    Thomas, P.; Dakshayini, B. S.; Kushwaha, H. S.; Vaish, Rahul

    2015-06-01

    Composites of poly(methyl methacrylate) (PMMA) and Sr2TiMnO6 (STMO) were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), thermo mechanical analysis (TMA) and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE) was measured between 40°C and 100°C for pure PMMA is 115.2 ppm/°C, which was decreased to 78.58 ppm/°C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition (Tg) temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMA+STMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.

  11. Hybrid effects of zirconia nanoparticles with aluminum borate whiskers on mechanical properties of denture base resin PMMA.

    Science.gov (United States)

    Zhang, Xiu-Yin; Zhang, Xin-Jing; Huang, Zhuo-Li; Zhu, Bang-Shang; Chen, Rong-Rong

    2014-01-01

    The aim of this study was to investigate the hybrid effects of ZrO₂ nanoparticles (nano-ZrO₂) and aluminum borate whiskers (ABWs) on flexural strength and surface hardness of denture base resin, polymethyl methacrylate (PMMA). Both nano-ZrO₂ and ABWs were modified by silane coupling agent (Z6030) before being mixed with PMMA. Various amounts of silanized nano-ZrO₂ and ABWs were mixed with PMMA to prepare ZrO₂-ABW/PMMA composites. Flexural strength and surface hardness were evaluated using three- point bending test and Vickers hardness test respectively. Fractured surfaces were also observed by scanning electron microscopy (SEM). The mechanical behaviors of silanized ZrO₂-ABW/PMMA composites were significantly improved. Flexural strength reached a maximum value of 108.01 ± 5.54 MPa when 2 wt% of nano-ZrO₂ was mixed with ABWs at a ZrO₂/ABW ratio of 1:2, amounting to an increase of 52% when compared with pure PMMA. Surface hardness achieved a maximum value of 22.50 ± 0.86 MPa when 3 wt% of nano-ZrO₂ was mixed with ABWs at the same ZrO₂/ABW ratio, which was an increase of 27% when compared with pure PMMA.

  12. Synthesis and characterization of hybrid silica/PMMA nanoparticles and their use as filler in dental composites

    Energy Technology Data Exchange (ETDEWEB)

    Canché-Escamilla, G., E-mail: gcanche@cicy.mx [Unidad de Materiales, Centro de Investigación Científica de Yucatán A.C. Calle 43 No. 130 Col. Chuburná de Hidalgo, Mérida, Yucatán 97200 (Mexico); Duarte-Aranda, S. [Unidad de Materiales, Centro de Investigación Científica de Yucatán A.C. Calle 43 No. 130 Col. Chuburná de Hidalgo, Mérida, Yucatán 97200 (Mexico); Toledano, M. [Facultad de Odontología, Universidad de Granada, Campus Universitario de Cartuja s/n, Granada 18071 (Spain)

    2014-09-01

    The effect of hybrid silica/poly(methylmethacrylate) (PMMA) nanoparticles on the properties of composites for dental restoration was evaluated. Hybrid nanoparticles with silica as core and PMMA as shell were obtained by a seeded emulsion polymerization process. Fourier transform infrared spectrum of the hybrid nanoparticles shows an intense peak at 1730 cm{sup −1}, corresponding to carbonyl groups (C=O) of the ester. The thermal stability of the hybrid particles decreases with increasing amounts of PMMA and the residual mass at 700 °C corresponds to the silica content in the hybrid particles. Composites were obtained by dispersing nanoparticles (silica or hybrid), as fillers, in a resin—bis glycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (40%/60% (w/w)). The paste was then placed in a mold and polymerized under light irradiation. During the preparation of the composites, with the hybrid nanoparticles, the monomers swell the PMMA shell and after photo-curing, a semi-interpenetrating network (semi-IPN) is obtained around the silica core. The properties of the composites, obtained using the hybrid nanoparticles, depend on the filler content and the amount of PMMA in the semi-IPN matrix. For composites with similar inorganic filler contents, the composites with low amounts of PMMA shell had higher modulus than those in which silica was used as the filler. - Highlights: • Hybrid nanoparticles silica/PMMA were used as fillers in dental composites. • The properties of the hybrid nanoparticle depend on the silica/PMMA content ratio. • A higher content of inorganic filler was obtained using hybrid nanoparticle. • Composites with higher modulus were obtained using hybrid nanoparticles. • A semi-IPN matrix between the PMMA shell and the resin is obtained.

  13. Impact of nucleation of carbonaceous clusters on structural, electrical and optical properties of Cr+-implanted PMMA

    Science.gov (United States)

    Arif, Shafaq; Rafique, M. Shahid; Saleemi, Farhat; Naab, Fabian; Toader, Ovidiu; Mahmood, Arshad; Aziz, Uzma

    2016-09-01

    Specimens of polymethylmethacrylate (PMMA) have been implanted with 400 keV Cr+ ions at different ion fluences ranging from 5 × 1013 to 5 × 1015 ions/cm2. The possible chemical reactions involved in the nucleation of conjugated carbonaceous clusters in implanted PMMA are discussed. Furthermore, impact of formation of carbonaceous clusters on structural, optical, electrical and morphological properties of implanted PMMA has been examined. The structural modifications in implanted PMMA are observed by Raman spectroscopy. The variation in optical band gap and Urbach energy is measured using UV-visible spectroscopic analysis. The effects of Cr+ ion implantation on electrical and morphological properties are investigated by four-probe apparatus and atomic force microscopy, respectively. The Raman spectroscopic analysis confirmed the formation of carbonaceous clusters with the transformation of implanted layer of PMMA into amorphous carbon. Simultaneously, the optical band gap of implanted PMMA has reduced from 3.13 to 0.85 eV. The increase in Urbach energy favors the decline in band gap together with the structural modification in implanted PMMA. As a result of Cr+ ion implantation, the electrical conductivity of PMMA has improved from 2.14 ± 0.06 × 10-10 S/cm (pristine) to 7.20 ± 0.36 × 10-6 S/cm. The AFM images revealed a decrease in surface roughness with an increment in ion fluence up to 5 × 1014 ions/cm2. The modification in the electrical, optical and structural properties makes the PMMA a promising candidate for its future utilization, as a semiconducting and optically active material, in various fields like plastic electronics and optoelectronic devices.

  14. The Roles of EMA in ABS/PMMA Alloy%EMA在ABS/PMMA合金中的作用

    Institute of Scientific and Technical Information of China (English)

    许家友; 林凯勉; 黄鹄斌; 梁以峰

    2012-01-01

    Effects of EMA on ABS/PMMA blends were studied by DSC,SEM and mechanical performance test. The experimental results showed that the EMA had compatibilizing and toughening effects on ABS/PMMA blends. Because the EMA contains vinyl group similarity to butadiene in ABS.and the same methyl-methacrylate group in PMMA, which could improve the interface compatibility between ABS and PMMA; At the same time,EMA dispersed as spherical in ABS/PMMA matrix and endured stress,the toughness of the ABS/PMMA blends could be obviously improved while increasing the content of EMA. The gloss of the surface of ABS/PMMA blends was affected by the compatibility of ABS/PMMA blends. When the content of EMA was 6 %,the gloss on surface of ABS/PMMA blends reached maximum.%通过DSC、SEM和力学性能测试研究了EMA在ABS/PMMA中的作用,结果表明:EMA对ABS/PMMA合金具有增容和增韧作甩.因为EMA含有与ABS中丁二烯结构相似的乙烯基,又含有与PMMA中相同的甲基丙烯酸甲酯,可以提高ABS/PMMA的界面相容性,但同时EMA在ABS/PMMA中呈球形分散,起应力集中物作用,能提高ABS/PMMA的韧性;EMA对ABS/PMMA增容程度影响着ABS/PMMA合金的表面光泽度,当EMA质量含量为6%时,ABS/PMMA合金的表面光泽度达到最大值.

  15. Piggyback secundário com LIO de PMMA para correção de surpresa refracional pós-facoemulsificação: resultados a longo prazo de 20 casos Secondary piggyback with PMMA IOL for the correction of refractive surprise after phacoemulsification long-term results of 20 cases

    Directory of Open Access Journals (Sweden)

    Fernando Cançado Trindade

    2013-02-01

    Full Text Available OBJETIVO: Avaliar os resultados a longo prazo da técnica do piggyback secundário utilizada para a correção de ametropia indesejável pós-facoemulsificação. MÉTODOS: Estudo retrospectivo que compreendeu 20 olhos (19 pacientes. A LIO utilizada foi de peça única de PMMA de 12,5 mm de comprimento total, com óptica oval de 5x6mm, com borda fina e arredondada e angulação de 10 graus com as hápticas. A mesma técnica cirúrgica foi utilizada em todos os casos, consistindo na confecção de túnel esclero-corneano com 5mm de largura, através do qual foi implantada a lente secundária no sulco ciliar. RESULTADOS: A ametropia indesejável foi corrigida em todos os casos. Não foi observado qualquer tipo de complicação durante ou após a cirurgia do piggyback secundário. CONCLUSÃO: A utilização de LIO de peça única de PMMA foi segura e eficaz no piggyback secundário para a correção das surpresas refracionais pós-facoemulsificação.PURPOSE: To evaluate long-term results of the secondary piggyback technique used for the correction of undesired ametropia after phacoemulsification. METHODS: Retrospective study comprising of 20 eyes (19 patients. The IOL used was a single-piece PMMA with an overall length of 12.5mm, a 5x6mm oval thin-edged optic with a 10-degree haptic angulation. The same technique was used in all cases, consisting of a scleral-corneal tunnel with a 5mm opening, through which the secondary intraocular lens was implanted into the ciliary sulcus. RESULTS: The undesired ametropia was corrected in all cases. No complications were observed during or after the secondary piggyback procedure. CONCLUSION: The use of a single-piece PMMA IOL proved to be safe and effective in secondary piggyback for the correction of refractive surprises after phacoemulsification.

  16. PVDF/PMMA/PEG/TiO2型聚合物隔膜的制备∗%PVDF/PMMA/PEG/TiO2 polymer diaphragm preparation

    Institute of Scientific and Technical Information of China (English)

    高虹; 韩剑

    2016-01-01

    Lithium ion battery gel polymer electrolyte is a kind of special state between solid and liquid,gel pol-ymer electrolyte has both solid electrolyte and good mechanical properties,but also has similar conductivity of liquid electrolyte ion,which plays an important role to improve the comprehensive performance of the battery. In order to improve the electrical conductivity and reduce the crystallinity of PVDF based polymer membranes, the main research of this topic is the contents for modified the PVDF polymer material,the concrete content is that blend PVDF and PMMA polymer,inorganic nano materials TiO2 and PEG,with the modified of the wet process(dry-wet process)to make it.Through testing the porosity and fluid absorption rate,the combination of scanning electron microscopy SEM and electrochemical workstation to test the sample characterization,finally the best one is:polymer of solvent percentage is 8%,PMMA accounted for 30% of the polymer mass,PEG content is 30%,nano TiO2 addition amount of 5%,the solvent content is 3%,the reaction temperature is 45 ℃.Ionic conductivity of PVDF/PMMA/PEG/TiO2 polymer of up to 5.2 mS/cm,the imbibition rate reached 345%,tensile strength is 1 183 kg/cm2 ,the electrochemical stability window was 4.68 V,higher than 4.5 V, the electrolyte system compatibility and conductivity is significantly improved.To meet the normal needs of lithium ion batteries.%为提高锂离子电池聚偏氟乙烯(PVDF)基聚合物隔膜的导电性和降低 PVDF 基聚合物隔膜的结晶度,引入聚甲基丙烯酸甲酯(PMMA)与聚偏氟乙烯(PVDF)进行共混,掺杂有机添加剂 PEG 和无机纳米材料 TiO2,采用相转化方法制备 PVDF/PMMA/PEG/TiO2型聚合物隔膜.通过对制备的 PVDF/PMMA/PEG/TiO2型多孔膜吸液率、离子电导率、微观形貌和电化学性能等的分析研究,确定制膜的最佳工艺条件为聚合物浓度为8%, PMMA占聚合物质量百分比为30%,PEG含量为30%,纳米TiO2含量为5%,C2 H5 OH

  17. Comparison of Trans-scleral Fixation of PMMA and Foldable Intraocular Lens in Children

    Institute of Scientific and Technical Information of China (English)

    Yuping Zou; Zhende Lin; Bo Feng; Shaozhen Li

    2001-01-01

    Purpose: To observe the difference of the effects of PMMA and foldable intraocular lenses (IOLs) trans-sclerally fixed in pediatric eyes. Methods: Thirty-two children (43 eyes) who had undergone trans-scleral fixation of IOL were retrospected, of whom 5 children were implanted PMMA IOL in both eyes, 6children were implanted PMMA IOL in one eye and foldable IOL in the other eye, 12children were implanted foldable IOL in one eye and 9 chilrden were implanted PMMA IOL in one eye. Mean age was 5.3 years ( range 2.5 ~ 12 years ). Twelve children had traumatic cataract and the others congenital cataract before lens extraction. Results: Foldable group (18 eyes ): Mean follow-up was 12.1 months. Visual acuity (VA): compared with the best corrected VA before IOL fixation, postoperative best corrected VA improved in 16 eyes, remained unchanged in 2 eyes. In 14 eyes, one or two stitches were needed to seal the incision. Complications: Severe anterior chamber reaction was seen in 3 eyes. Intraocular bleeding was found in 3 eyes. IOL decentration was detected in 1 eye. Iris capture of IOL was seen in one eye. PMMA group (25 eyes ):Mean follow-up was 20.3 months. Visual acuity (VA): compared with the best corrected VA before IOL fixation, postoperative best corrected VA improved in 19 eyes,remained unchanged in 5 eyes and got worse in one eye. In 24 eyes, one to three stitches were needed to seal the incision. Complications: Severe anterior chamber reaction was seen in 5 eyes. Intraocular bleeding was found in 4 eyes. IOL decentration was seen in one eye. Iris capture of IOL was seen in 3 eyes. Intraocular pressure elevated in one eye. Conclusion: Our study shows that trans-scleral fixation of IOL is a safe procedure in pediatric eyes. Foldable IOL showed similar effect compared with PMMA IOL in pediatric trans-scleral fixation. Eye Science 2001; 17:61 ~ 64.

  18. Stress effects in prism coupling measurements of thin polymer films

    Science.gov (United States)

    Agan, S.; Ay, F.; Kocabas, A.; Aydinli, A.

    2005-02-01

    Due to the increasingly important role of some polymers in optical waveguide technologies, precise measurement of their optical properties has become important. Typically, prism coupling to slab waveguides made of materials of interest is used to measure the relevant optical parameters. However, such measurements are often complicated by the softness of the polymer films when stress is applied to the prism to couple light into the waveguides. In this work, we have investigated the optical properties of three different polymers, polystyrene (PS), polymethyl-methacrylate (PMMA), and benzocyclobutane (BCB). For the first time, the dependence of the refractive index, film thickness, and birefringence on applied stress in these thin polymer films was determined by means of the prism coupling technique. Both symmetric trapezoid shaped and right-angle prisms were used to couple the light into the waveguides. It was found that trapezoid shaped prism coupling gives better results in these thin polymer films. The refractive index of PMMA was found to be in the range of 1.4869 up to 1.4876 for both TE and TM polarizations under the applied force, which causes a small decrease in the film thickness of up to 0.06 μm. PMMA waveguide films were found not to be birefringent. In contrast, both BCB and PS films exhibit birefringence albeit of opposing signs.

  19. Focusing high-energy x-rays by a PMMA compound x-ray lens on Beijing synchrotron radiation facility

    Institute of Scientific and Technical Information of China (English)

    Le Zi-Chun; Liang Jing-Qiu; Dong Wen; Zhu Pei-Ping; Peng Liang-Qiang; Wang Wei-Biao; Huang Wan-Xia; Yuan Qing-Xi; Wang Jun-Yue

    2007-01-01

    The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors' recent research on a polymethyl methacrylate (PMMA) compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.

  20. High efficiency enrichment of low-abundance peptides by novel dual-platform graphene@SiO2@PMMA.

    Science.gov (United States)

    Yin, Peng; Zhao, Man; Deng, Chunhui

    2012-11-21

    For the first time, dual-platform graphene@SiO(2)@poly(methyl methacrylate) (PMMA) material was synthesized, and successfully applied to efficiently enrich low-abundance peptides for mass spectrometry analysis.

  1. Pump-probe imaging of the fs-ps-ns dynamics during femtosecond laser Bessel beam drilling in PMMA.

    Science.gov (United States)

    Yu, Yanwu; Jiang, Lan; Cao, Qiang; Xia, Bo; Wang, Qingsong; Lu, Yongfeng

    2015-12-14

    A pump-probe shadowgraph imaging technique was used to reveal the femtosecond-picosecond-nanosecond multitimescale fundamentals of high-quality, high-aspect-ratio (up to 287:1) microhole drilling in poly-methyl-meth-acrylate (PMMA) by a single-shot femtosecond laser Bessel beam. The propagation of Bessel beam in PMMA (at 1.98 × 10⁸ m/s) and it induced cylindrical pressure wave expansion (at 3000-3950 m/s in radius) were observed during drilling processes. Also, it was unexpectedly found that the expansion of the cylindrical pressure wave in PMMA showed a linear relation with time and was insensitive to the laser energy fluctuation, quite different from the case in air. It was assumed that the energy insensitivity was due to the anisotropy of wave expansion in PMMA and the ambient air.

  2. A comparative study on CdS: PEO and CdS: PMMA nanocomposite solid films

    Energy Technology Data Exchange (ETDEWEB)

    Padmaja, S. [Thin film centre, PSG College of Technology, Coimbatore (India); Jayakumar, S., E-mail: s_jayakumar_99@yahoo.com [Department of Physics, PSG Institute of Technology and Applied Research, Coimbatore (India); Balaji, R.; Vaideki, K. [Thin film centre, PSG College of Technology, Coimbatore (India)

    2016-08-15

    Cadmium Sulphide (CdS) nanoparticles were reinforced in Poly(ethylene Oxide) (PEO) and Poly(methyl methacrylate) (PMMA) matrices by in situ technique. The presence of CdS in PEO and PMMA matrix was confirmed using X-ray photoelectron spectroscopy (XPS). Fourier Transform Infrared spectroscopy (FTIR) analysis disclosed the co-ordination of CdS in the matrices. Thermal analysis of the nanocomposites was carried out using Differential Scanning calorimetric studies (DSC). The optical studies using UV–vis spectroscopy were carried out to find the band gap of the materials and the absorption onset. The CdS particle size in the matrices was found by Effective Mass Approximation (EMA) model using the band gap values and was confirmed by TEM studies. The surface trapped emissions of the nanocomposites were observed from the photoluminescence (PL) spectra. The distribution of CdS particles in the polymer matrices were presented by Atomic force microscopic studies (AFM).

  3. Variations in backscatter observed in PMMA whole-body dosimetry slab phantoms.

    Science.gov (United States)

    Schwahn, Scott O; Gesell, Thomas F

    2008-01-01

    Polymethyl methacrylate (PMMA) is a useful material for dosimetry phantoms in many ways including approximate tissue equivalence, stability, accessibility and ease of use. However, recent studies indicate that PMMA may have some unanticipated variation in backscatter from one phantom to another. While the reasons behind the variations have not been identified, it has been demonstrated that the backscatter from one phantom to another may vary by as much as 15%, resulting in a dosemeter response variation of as much as 5%. This unexpected contribution to uncertainty in delivered dose to a dosemeter may be quite large compared to the normally estimated uncertainty, potentially causing problems with calibration and performance testing. This paper includes data supporting the differences in backscatter among phantoms, and results from tests on the phantoms performed in an effort to identify possible causes.

  4. Optimization of multiplexed holographic gratings in PQ-PMMA for spectral-spatial imaging filters.

    Science.gov (United States)

    Luo, Yuan; Gelsinger, Paul J; Barton, Jennifer K; Barbastathis, George; Kostuk, Raymond K

    2008-03-15

    Holographic gratings formed in thick phenanthrenquinone- (PQ-) doped poly(methyl methacrylate) (PMMA) can be made to have narrowband spectral and spatial transmittance filtering properties. We present the design and performance of angle-multiplexed holographic filters formed in PQ-PMMA at 488 nm and reconstructed with a LED operated at approximately 630 nm. The dark delay time between exposure and the preillumination exposure of the polymer prior to exposure of the holographic area are varied to optimize the diffraction efficiency of multiplexed holographic filters. The resultant holographic filters can enhance the performance of four-dimensional spatial-spectral imaging systems. The optimized filters are used to simultaneously sample spatial and spectral information at five different depths separated by 50 microm within biological tissue samples.

  5. Eu(Ⅲ) complex-doped PMMA having fast radiation rate and high emission quantum efficiency

    Institute of Scientific and Technical Information of China (English)

    Jin Li Zhang; Bo Wei Chen; Xuan Luo; Kai Du

    2012-01-01

    Three Eu(Ⅲ) ternary complexes,Eu(hfa-H)3(Phen),Eu(hfa-H)3(Bipy) and Eu(hfa-H)3(Bath) (hfa =hexafluoroacetylacetonate,Phen =1,10-phenanthroline,Bipy =2,2′-bipyridine,Bath =bathophenanthroline),were synthesized.Their luminescent properties were studied by incorporating deuterated Eu(Ⅲ) complexes in a poly(methylmethacrylate) (PMMA) matrix,and the results indicated that luminescent PMMA including Eu(hfa-D)3(Bath) showed promising results for applications to novel organic Eu(Ⅲ) devices,such as the high-power laser materials.Additionally,all the three Eu(Ⅲ) complexes exhibited good thermostabilization.

  6. Luminescent Solar Concentrators Fabricated by Dispersing Rare Earth Particles in PMMA Waveguide

    Directory of Open Access Journals (Sweden)

    Cheng Liu

    2014-01-01

    Full Text Available Luminescent solar concentrators (LSCs were fabricated by dispersing CaAlSiN3 : Eu2+ particles in a PMMA waveguide. A series of LSCs (dimension 5.0 cm × 5.0 cm × 0.5 cm with different CaAlSiN3 : Eu2+ particle concentration were obtained and their performance was evaluated. The maximum optical concentration ratio is 1.23 with a power conversion efficiency of 1.44% for the LSC containing 0.5 wt% CaAlSiN3 : Eu2+ particles concentration. This strategy of dispersing rare earth particles in PMMA waveguide represents an alternative approach to producing highly durable LSCs.

  7. PMMA and FEP surface modifications induced with EUV pulses in two selected wavelength ranges

    Energy Technology Data Exchange (ETDEWEB)

    Bartnik, A.; Fiedorowicz, H.; Jarocki, R.; Kostecki, J.; Szczurek, M. [Military University of Technology, Institute of Optoelectronics, Warsaw (Poland)

    2010-01-15

    Surface modification of PMMA and FEP polymers using extreme ultraviolet (EUV) in two spectral ranges was investigated. A laser-plasma EUV source based on a double stream gas puff target equipped with an Au coated ellipsoidal collector was used for the experiment. The spectrum of the focused radiation from Kr plasma consisted of a narrow feature with a maximum at 10 nm and a long-wavelength tail up to 70 nm. Al and Zr filters were employed for the selection of radiation from these two spectral regions. The radiation fluences in the two cases were comparable. Polymer samples were mounted in the focal plane of the EUV collector and irradiated for 1-2 min with a 10 Hz repetition rate. Weak ablation accompanied by creation of micro- and nanostructures of different kinds was obtained in both cases. Significant differences in the surface structures after irradiation of PMMA and FEP in these two spectral regions were revealed. (orig.)

  8. Preparation of raspberry-like PMMA/SiO2 nanocomposite particles

    Institute of Scientific and Technical Information of China (English)

    Chen Min; You Bo; Zhou Shuxue; Wu Limin

    2006-01-01

    Water-borne raspberry-like PMMA/SiO2 nanocom-posite particles were prepared via free radical copolymerization of methyl methacrylate (MMA) with 1-vinylimidazole (1-VID) in the presence of ultrafine aqueous silica sols.The acid-base interaction between hydroxyl groups (acidic) of silica surfaces and amino groups (basic) of 1-VID was strong enough for promoting the formation of long-standing stable PMMA/SiO2 nanocomposite particles when 10 mol% or more 1-VID as auxiliary monomer was used.The average particle sizes and the silica contents of the nanocomposite particles were in the ranges from 120-330 nm and 15%-20%,respectively.TEM and SEM observations indicated a raspberry-like morphology of the obtained nanocomposite particles.

  9. Synthesis and Melt Self-Assembly of PS-PMMA-PLA Triblock Bottlebrush Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, Justin; Rzayev, Javid [Buffalo

    2014-07-03

    Polystyrene–poly(methyl methacrylate)–polylactide (PS–PMMA–PLA) triblock bottlebrush copolymer with nearly symmetric volume fractions was synthesized by grafting from a symmetrical triblock backbone and the resulting melt was characterized by scanning electron microscopy and small-angle X-ray scattering. The copolymer backbone was prepared by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization of solketal methacrylate (SM), 2-(bromoisobutyryl)ethyl methacrylate (BIEM), and 5-(trimethylsilyl)-4-pentyn-1-ol methacrylate (TPYM). PMMA branches were grafted by atom transfer radical polymerization from the poly(BIEM) segment, PS branches were grafted by RAFT polymerization from the poly(TPYM) block after installment of the RAFT agents, while PLA side chains were grafted from the deprotected poly(SM) block. The resulting copolymer was found to exhibit a lamellae morphology with a domain spacing of 79 nm. Differential scanning calorimetry analysis indicated that PMMA was preferentially mixing with PS while phase separating from PLA domains.

  10. Preparation and characterization of PMMA/graphite conductive composite%PMMA/石墨导电复合材料的制备与表征

    Institute of Scientific and Technical Information of China (English)

    黄光平; 洪若瑜; B.Xu; 李洪钟; 尉东光

    2008-01-01

    以可膨化石墨为原料,高温处理得到膨化石墨,再经过超声处理,得到纳米薄片石墨.将得到的纳米薄片石墨与甲基丙烯酸甲酯单体在超声作用下预聚,灌模,得到块状的聚甲基丙烯酸甲酯(PMMA)/石墨复合材料.用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、选区电子衍射SAD、红外、热重等分析仪器表征了纳米石墨薄片及PMMA/石墨复合材料.测试了复合材料的力学、电学性能,发现在室温下该复合材料的渗滤阀值为1.3%(wt),且保证石墨含量在1.4%(wt)时,即可保证复合材料具有良好的电学和力学性能.

  11. Structural, thermal, optical properties and cytotoxicity of PMMA/ZnO fibers and films: Potential application in tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Balen, Rodrigo; Vidotto da Costa, Wilian; Lara Andrade, Jéssica de; Piai, Juliana Francis [Programa de Pós-Graduação em Química, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); Muniz, Edvani Curti [Programa de Pós-Graduação em Química, Departamento de Química, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); Programa de Pós-Graduação em Biotecnologia Aplicada à Agricultura, Universidade Paranaense (UNIPAR), 87502-210, Umuarama, PR (Brazil); Programa de Pós- Graduação em Ciências de Materiais & Engenharia, Universidade Tecnológica Federal do Paraná (UTFPR-LD), 86036-370, Londrina, PR (Brazil); Companhoni, Mychelle Vianna; Nakamura, Tânia Ueda [Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900, Zona Sete, Maringá, PR (Brazil); and others

    2016-11-01

    Highlights: • Films and fibers of PMMA/ZnO nanocomposite were prepared. • ZnO NPs incorporated into PMMA fibers reduces their diameter and beads presence. • PMMA films containing ZnO exhibit higher thermal stability than pure polymer. • PMMA/ZnO nanocomposites show improved optical properties compared to pure polymer. • PMMA/ZnO shows potential for applications in tissue engineering. - Abstract: Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The surfaces of the fibers exhibited greater hydrophobicity, compared to the films, with contact angles of around 120° and 94°, respectively. PMMA films containing ZnO exhibited higher thermal stability than the pure polymer, while the corresponding fibers did not show any changes in thermal stability. The dispersion of the ZnO NPs at the surface and in the bulk of the nanocomposites appeared to be relatively homogeneous. ZnO improved the optical properties of the PMMA, with an intense absorption band near 370 nm observed for all the nanocomposites, which also exhibited luminescence with emission in the near-UV region, both attributed to ZnO. Biological tests demonstrated that fibers and films with up to 1% of ZnO exhibited good performance in the proliferation of fibroblast cells, indicating their potential for applications in tissue engineering. The fibers provided higher cell viability than the films, presumably due to their greater surface area and/or more suitable surface morphology. Nanocomposites with 15% ZnO inhibited cell proliferation, due to the cytotoxicity of the ZnO NPs. Although several applications of PMMA have been suggested by biomedical researchers, until now there have been no reports on the specific

  12. PVDF/PMMA/PEG polymer diaphragm preparation%PVDF/PMMA/PEG 型聚合物隔膜的制备

    Institute of Scientific and Technical Information of China (English)

    高虹; 陈爱雨; 王守兵

    2015-01-01

    Lithium ion battery gel polymer electrolyte used instead of traditional liquid electrolyte has many ad-vantages,the gel is a kind of special state between solid and liquid,gel polymer electrolyte has both solid elec-trolyte and good mechanical properties,but also has similar conductivity of liquid electrolyte ion,which plays an important role to improve the comprehensive performance of the battery.The main research of this topic is the contents for modified the PVDF polymer material,the concrete content is that blend PVDF and PMMA pol-ymer,then add the plasticizing PEG-400,with the modified of the wet process(dry-wet process)to make it. Through testing the porosity and fluid absorption rate,the combination of scanning electron microscopy SEM and electrochemical workstation to test the sample characterization,finally the best one is:polymer of solvent percentage is 8%,PVDF∶PMMA = 7∶3,plasticizer content is 30%,the solvent content is 3%,the reaction temperature is 45 ℃.Ionic conductivity of PVDF/PMMA/PEG polymer of up to 2.848mS/cm,the electrolyte system compatibility and conductivity is significantly improved.%为提高锂离子电池聚偏氟乙烯(PVDF)基聚合物隔膜对电解液体系的亲和性和导电性,引入聚甲基丙烯酸甲酯(PMMA)与聚偏氟乙烯(PVDF)进行共混,并添加有机增塑剂聚乙二醇 PEG-400对 PVDF基聚合物隔膜进行改性研究.采用先干法后湿法的相转化方法制备 PVDF/PMMA/PEG 型聚合物隔膜.通过对制备的聚合物隔膜的孔隙率、吸液率、微观形貌和电化学性能的分析研究,确定制膜的最佳工艺条件为聚合物占溶剂质量百分比为8%,PVDF∶PMMA=7∶3,增塑剂含量为30%,非溶剂含量为3%,反应温度为45℃,在此最佳工艺条件下制备的 PVDF/PM-MA/PEG 隔膜的离子电导率可达2.848 mS/cm,对电解液体系的亲和性和导电性得到显著提高.

  13. PVDF/PMMA/TiO2型聚合物隔膜的制备∗%PVDF/PMMA/TiO2 polymer diaphragm preparation

    Institute of Scientific and Technical Information of China (English)

    高虹; 韩剑; 王守兵

    2016-01-01

    Lithium ion battery gel polymer electrolyte is a kind of special state between solid and liquid,gel pol-ymer electrolyte has both solid electrolyte and good mechanical properties,but also has similar conductivity of liquid electrolyte ion,which plays an important role to improve the comprehensive performance of the battery. In order to improve the electrical conductivity and reduce the crystallinity of PVDF based polymer membranes, the main research of this topic is the contents for modified the PVDF polymer material,the concrete content is that blend PVDF and PMMA polymer,inorganic nano materials TiO2 ,with the modified of the wet process (dry-wet process)to make it.Through testing the porosity and fluid absorption rate,the combination of scan-ning electron microscopy SEM and electrochemical workstation to test the sample characterization,finally the best one is:polymer of solvent percentage is 5%,m(PVDF)∶m(PMMA)=72∶28,nano TiO2 addition a-mount of 5%,the solvent content is 3%,the reaction temperature is 5 5 ℃.Ionic conductivity of PVDF/PM-MA/TiO2 polymer of up to 2.64 mS/cm,The imbibition rate reached 109.76%,The electrochemical stability window was 4.86 V,higher than 4.5 V,the electrolyte system compatibility and conductivity is significantly im-proved.To meet the normal needs of lithium ion batteries.%为提高锂离子电池聚偏氟乙烯(PVDF)基聚合物隔膜的导电性和降低 PVDF 基聚合物隔膜的结晶度,引入聚甲基丙烯酸甲酯(PMMA)与聚偏氟乙烯(PVDF)进行共混,掺杂无机纳米材料TiO2,采用相转化方法制备PVDF/PMMA/TiO2型聚合物隔膜.通过对制备的PVDF/PMMA/TiO2型多孔膜吸液率、微观形貌和电化学性能的分析研究,确定制膜的最佳工艺条件为聚合物浓度为5%,PVDF∶PMMA为72∶28,纳米TiO2添加量为5%,非溶剂添加量为3%,水浴温度为55℃.该方案下制备的多孔膜结晶度较纯 PVDF薄膜结晶度降低,吸液率达到109.76%,离子电导率为2.64 mS

  14. White emission using mixtures of CdSe quantum dots and PMMA as a phosphor

    Science.gov (United States)

    Chung, Wonkeun; Park, Kwanhwi; Yu, Hong Jeong; Kim, Jihyun; Chun, Byung-Hee; Kim, Sung Hyun

    2010-02-01

    White light emitting diodes (LEDs) were fabricated using an InGaN 460 nm blue emission LED chip as the excitation source and CdSe quantum dots dispersed in PMMA as the phosphor. CdSe quantum dots were synthesized by the wet chemical method using CdO and Selenium powder as precursors. The three different size, 2.9, 3.4 and 4.3 nm in diameter, of CdSe quantum dots obtained using this method exhibited emission peaks at 555, 580 and 625 nm, respectively with a quantum yield of 10-30%. Mixed phosphors containing different weight ratio of CdSe and PMMA (1:0.1, 1:1, 1:5 and 1:10 wt%) were deposited on the LED chip to investigate the effects of different weight ratios of CdSe and PMMA on the performance of the white LEDs. The fabricated white LEDs that contained CdSe and PMMA weight ratio at 1:10 showed the best performance and the CIE color coordinates varied less with different applied currents. The luminous efficiency of single phosphor (580 nm CdSe) white LEDs was 5.62 lm/W with a CRI of 15.7, whereas the luminous efficiency of dual phosphors (555, 625 nm CdSe) white LEDs was 3.79 lm/W with a CRI of 61.4 at 20 mA. The CIE coordinates of single and dual phosphors white LEDs varied from (0.33, 0.28) to (0.29, 0.26) and from (0.39, 0.33) to (0.39, 0.32), respectively, when the working current ranged from 5 to 80 mA.

  15. PMMA vertebroplasty in patients with malignant vertebral destruction of the thoracic and lumbar spine

    Directory of Open Access Journals (Sweden)

    Böker, Dieter-Karsten

    2003-11-01

    Full Text Available Object: Patients with osteolytic metastases frequently suffer from serious local and radicular pain. Pathophysiologically, local pain arises from skeletal instability, whereas radicular pain originates from compression of nerve roots by local tumor growth. Causal treatment of osteolytic metastases in disseminated malignant disease is very difficult. Resection of vertebrae, in combination with ventro-dorsal stabilization, is a complex treatment for patients with a limited life expectancy. Percutaneous polymethylmethacrylate (PMMA vertebroplasty is a new and easy method of relieving patients' pain. In addition, it is both cost effective and safe. Pain is reduced immediately after treatment. Due to the regained vertebral stability, early mobilization of the patients is possible. Methods: A total of 22 patients with osteolytic malignancies of the thoracic and lumbar spine were treated with PMMA vertebroplasty. Prior to and after surgery, then six weeks and six months after discharge from hospital, patients answered the Oswestry Low Back Pain Disability (OLBPD Questionnaire for assessment of treatment-related change in disability. Percutaneous vertebroplasty was performed in a total of 19 patients. In three patients with tumor related compression of nerve roots an open neurolysis was performed followed by vertebroplasty. Results: A total of 86% of patients reported a significant pain reduction. Vertebroplasty was highly beneficial for patients with pain related to local instability of the spine, but less so in patients with additional nerve root compression. Extravasation of PMMA beyond the vertebral margins was observed in 23% of the cases. No treatment-related clinical or neurological complications were seen. Conclusions: PMMA vertebroplasty is a useful and safe method of pain relief for patients with malignant osteolytic diseases of the thoracic and lumbar spine.

  16. Electrical conduction mechanism of polyvinyl chloride (PVC)–polymethyl methacrylate (PMMA) blend film

    Indian Academy of Sciences (India)

    R S Gulalkari; Y G Bakale; D K Burghate; V S Deogaonkar

    2007-09-01

    The electrical conduction mechanism in polyvinyl chloride (PVC)–polymethyl methacrylate (PMMA) blend film has been studied at various temperatures in the range 313 K to 353 K. The results are presented in the form of – characteristics. Analysis has been made in the light of Poole–Frenkel, Fowler–Nordheim, Schottky, log() vs. plots and Arrhenius plots. It is observed that, Schottky–Richardson mechanism is primarily responsible for the observed conduction.

  17. Low-Threshold Random Laser with One Mirror and Feedbacks in PMMA Nano-Composite Films

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-Hong; TAO Xiao-Ming; XUE Pu; KWAN Kai-Cheong; DENG Jian-Guo

    2005-01-01

    @@ A low-threshold random laser with one mirror and feedback is investigated in the PMMA film containing rhodamine 590 and TiO2 nano-particles. Incoherent and coherent laser emission is observed. Effect of particle concentration on light emission is explored, and the optimum particle concentration is obtained. Optical microscopy and scanning probe microscopy are used to investigate the film structure, and the principle of incoherent and coherent laser is analysed.

  18. Structural properties 3,16-bis triisopropylsilylethynyl (pentacene) (TIPS-pentacene) thin films onto organic dielectric layer using slide coating method

    Energy Technology Data Exchange (ETDEWEB)

    Rusnan, Fara Naila; Mohamad, Khairul Anuar; Seria, Dzul Fahmi Mohd Husin; Saad, Ismail; Ghosh, Bablu K.; Alias, Afishah [Nano Engineering & Materials (NEMs) Research Group, Faculty of Engineering Universiti Malaysia Sabah, Kota Kinabalu 88400 Sabah (Malaysia)

    2015-08-28

    3,16-bis triisopropylsilylethynyl (Pentacene) (TIPS-Pentacene) compactable interface property is important in order to have a good arrangement of molecular structure. Comparison for TIPS-Pentacene deposited between two different surface layers conducted. 0.1wt% TIPS-Pentacene diluted in chloroform were deposited onto poly(methylmeaclyrate) (PMMA) layered transparent substrates using slide coating method. X-ray diffraction (XRD) used to determine crystallinity of thin films. Series of (00l) diffraction peaks obtained with sharp first peaks (001) for TIPS-Pentacene deposited onto PMMA layer at 5.35° and separation of 16.3 Å. Morphology and surface roughness were carried out using scanning electron microscope (SEM) and surface profilemeter LS500, respectively.TIPS-Pentacene deposited onto PMMA layer formed needled-like-shape grains with 10.26 nm surface roughness. These properties were related as thin film formed and its surface roughness plays important role towards good mobility devices.

  19. Experience with polymethylmethacrylate 30% (PMMA) facial filling in patients with facial HIV lipoatrophy using of local anesthesia dentistry

    OpenAIRE

    Matsuda, E; F. Soares; Brigido, L.

    2012-01-01

    Background HIV-associated lipoatrophy in a common and stigmatizing side effect of HIV infection, is aggravated by antiretroviral therapy; its presence causes distress and compromises adherence to therapy. PMMA filling is often associated with pain and discomfort. Objective To evaluate outpatient intervention using local dentistry anesthesia. Methods Patients complaining of facial lipoatrophy, from 10/2007 to 11/2011, were offered the filling with PMMA. Cases with bleeding potential, acute or ...

  20. Fabrication of Prototype of Artificial Retina Adapted to a Curved Image Plane Based on Arrayed PMMA Microfibers

    OpenAIRE

    2011-01-01

    The traditional visual prosthesis combines both a camera and an electrode array implanted on the visual neural networks. Here, we introduce a new design of artificial retina which integrate the transmission of image and the electrical stimulation of cortical neurons on a single PMMA micro fiber. It is comprised of multiple PMMA microfibers with both ends connected with one flexible and one rigid substrates. The flexible one is a PDMS mold of microrods and ready to conform to a curved image pl...

  1. A study on compression paddle materials to reduce radiation exposure dose during mammography: PC and PMMA and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Dong Hee [Dept. of Radiological Science, Far east University, Eumsung (Korea, Republic of); Jung, Hong Ryang [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of)

    2015-06-15

    This study was designed the band material in order to reduce the exposure pressure of the breast and the material was measured of Radiolucent and radiation properties with a radiation materials of PC, PMMA, Carbon. Also the image quality by image analysis to obtain the following results are below: Unfors Xi dosimetry using radiation transmittance when the results of 8.353 mGy is measured after removal of the cuff, the PC 6.308 mGy, PMMA 6.223 mGy, Carbon 7.218 mGy were measured respectively. Semi-layer PC 0.375 mmAl, PMMA 0.370 mmAl, with Carbon 0.360 mmAl Carbon, PC, PMMA was higher radiation properties and transparency in order. InLight / OSL NanoDotTM dosimeter was used in the cuff and then removed by placing the dosimeter measured results center on 1.143 mGy, at the edge 12.56 mGy, on the central PC 8.990 mGy, at the edge 10.291 mGy, PMMA center on 8.391 mGy , the edge 9.654 mGy, on Carbon center 9.581 mGy, 11.313 mGy were measured at the edge of Carbon, PC, PMMA showed a high permeability in order. Image Pixel average J is then removed from the cuff 976.655, PC 831.032, PMMA 819.069, Carbon 897.118 Carbon, PC, PMMA was measured by high order.

  2. Processing and characterization of PMMA/PI composites reinforced with surface functionalized hexagonal boron nitride

    Science.gov (United States)

    Mittal, Garima; Rhee, Kyong Yop; Park, Soo Jin

    2017-09-01

    Poly(methyl methacrylate) (PMMA) is acknowledged as a conventional polymer matrix because of its light weight, low friction, optical clarity, and environmental stability, with properties including UV resistance and moisture resistance. In the present study, PMMA/polyimide (PI)/hexagonal boron nitride (hBN) composites were processed by incorporating PI and hBN powder into the PMMA matrix. To augment the dispersion, the surfaces of hBN particles were functionalized with 3-aminopropyltriethoxysilane (3-APTS), which serves as a coupling agent. Two cases of composites were considered: one with as-received hBN and another one with silanized hBN. For validation of changes after silane treatment, X-ray diffraction, and Fourier transform infra-red were performed. The changes in morphology after surface treatment were analyzed through field-emission scanning electron microscope and high-resolution transmission electron microscope. The effects of hBN functionalization on the thermal properties of the composites were analyzed by thermo-gravimetric analysis. The tribological properties of the composites were studied by friction and wear tests and the morphology of the wear track was investigated using a surface profilometer and field-emission scanning electron microscope. The outcomes of these investigations indicated that the composite with silanized hBN exhibited superior tribological properties in comparison to the composites with as-received hBN.

  3. CZE study on adsorption processes of aliphatic and aromatic amines on PMMA chip.

    Science.gov (United States)

    Masár, Marián; Kruk, Pavol; Luc, Milan; Bodor, Róbert; Danč, Ladislav; Troška, Peter

    2013-02-01

    Adsorption processes on a PMMA chip linked with CZE separations of a group of 13 aliphatic and aromatic mono- and di-amines were studied. Due to the lack of chromophores within aliphatic amines, contact conductivity detection implemented directly onto the chip was used for monitoring of cationic CZE separations. To prevent an adsorption of studied amines to the chip channels, the surface of PMMA chip was modified by dynamic coating. Different surface modifiers, such as aliphatic oligoamines (diethylenetriamine and triethylenetetramine), were added to the BGE solutions filling the chip channels. The effect of various concentrations of surface modifiers on peak profiles and separation parameters of amines was monitored. Of these, mainly, aliphatic di-amines and aromatic mono-amines adversely affected the CZE resolution of a whole group of analytes by their strong adsorption to the chip channels. A propionate BGE with pH 3.2 containing 100 μM triethylenetetramine and 25 mM 18-crown-6-ether was found suitable for CZE resolution of 12 from a total of 13 amines studied. Simple dynamic modification of the surface of PMMA chip enabled fast (analysis time lasted 9 min), sensitive (sub-μM LODs reached) and reproducible (1-3% RSD of the peak areas) CZE analysis of the aliphatic and aromatic amines.

  4. Antibiotic-eluting hydrophilized PMMA bone cement with prolonged bactericidal effect for the treatment of osteomyelitis.

    Science.gov (United States)

    Oh, Eun Jo; Oh, Se Heang; Lee, In Soo; Kwon, Oh Soo; Lee, Jin Ho

    2016-05-01

    Osteomyelitis is still considered to be one of the major challenges for orthopedic surgeons despite advanced antiseptic surgical procedures and pharmaceutical therapeutics. In this study, hydrophilized poly(methyl methacrylate) (PMMA) bone cements containing Pluronic F68 (EG79PG28EG79) as a hydrophilic additive and vancomycin (F68-VAcements) were prepared to allow the sustained release of the antibiotic for adequate periods of time without any significant loss of mechanical properties. The compressive strengths of the bone cements with Pluronic F68 compositions less than 7 wt% were not significantly different compared with the control vancomycin-loaded bone cement (VAcement). TheF68 (7 wt%)-VAcement showed sustained release of the antibiotic for up to 11 weeks and almost 100% release from the bone cement. It also prohibited the growth ofS. aureus(zone of inhibition) over six weeks (the required period to treat osteomyelitis), and it did not show any notable cytotoxicity. From an animal study using a femoral osteomyelitis rat model, it was observed that theF68 (7 wt%)-VAcement was effective for the treatment of osteomyelitis, probably as a result of the prolonged release of antibiotic from the PMMA bone cement. On the basis of these findings, it can be suggested that the use of Pluronic F68 as a hydrophilic additive for antibiotic-eluting PMMA bone cement can be a promising strategy for the treatment of osteomyelitis.

  5. Overview of the performances of PMMA-SI-POF communication systems

    Science.gov (United States)

    Straullu, Stefano; Abrate, Silvio

    2013-01-01

    Poly-Methyl-MethAcrilate based optical fibers with Step-Index profile and 1 mm core diameter (PMMA-SI-POF) are widely deployed in automobile infotainment systems thanks to the MOST standards that adopt them as the preferred physical medium. However, thanks to their mechanical robustness and tolerance and their ease of installation, they make a suitable medium for local networking. Unfortunately, their good mechanical characteristics have to be paid in terms of performances, since PMMA-SI-POF based systems are severely limited in both bandwidth and attenuation. We will present a review of the best research results that have been obtained at the different speeds that are defined by the Ethernet standard: 10 Mb/s, 100 Mb/s and 1 Gb/s, showing that PMMA-SI-POF can easily overcome copper performances while being smaller, cheaper, easier to install in brownfield environment. To date, the following results have been obtained: 425 m at 10 Mb/s, 275 m at 100 Mb/s and 75 m at 1 Gb/s; these results have been obtained with commercial eye-safe components, and we believe that overcoming them requires in most cases the development of a new class of components. An overview of the different modulation formats that have been adopted, the most suitable equalization techniques and the best affordable components will be given. In the end, an overview of the current commercial systems performances and the road standardization procedures are taking will be given.

  6. Use of lead (II) sulfide nanoparticles as stabilizer for PMMA exposed to gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Olga Pinheiro; Albuquerque, Marilia Cordeiro Carneiro de; Aquino, Katia Aparecida da Silva; Araujo, Elmo Silvano de, E-mail: aquino@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Araujo, Patricia Lopes Barros de [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil)

    2015-03-15

    Lead (II) sulfide (PbS) were synthesized by sonochemical method and crystals with cubic structure exhibit aggregated nanoparticles with size in the range of 50-100 nm. Commercial Poly(methyl methacrylate) (PMMA) containing the PbS nanoparticles (PbS-NP) exposed to gamma irradiation were investigated and both the viscosity-average molar mass (Mv ) and degradation index (DI) values were measured. Ours results showed decreases in molar mass when the systems were gamma irradiated, i. e., random scission effects that take place in the main chain. On the other hand, DI results showed that the addition of PbS-NP at 0.3 wt% into the PMMA matrix decreased 100% the number of main chain scissions. Results about the free radical scavenger action of the PbS-NP were obtained by use of 2,2-diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl radical (DPPH) and are discussed in this study. Analysis of infrared spectra, refraction index, mechanical, and thermal properties showed influence of the PbS-NP in the physical behavior of PMMA. (author)

  7. Swift heavy ion irradiation effect on Cu-doped CdS nanocrystals embedded in PMMA

    Indian Academy of Sciences (India)

    Shweta Agrawal; Subodh Srivastava; Sumit Kumar; S S Sharma; B Tripathi; M Singh; Y K Vijay

    2009-12-01

    Semiconductor nanocrystals (NCs) have received much interest for their optical and electronic properties. When these NCs dispersed in polymer matrix, brightness of the light emission is enhanced due to their quantum dot size. The CdCuS NCs have been synthesized by chemical route method and then dispersed in PMMA matrix. These nanocomposite polymer films were irradiated by swift heavy ion (SHI) (100 MeV, Si+7 ions beam) at different fluences of 1 × 1010 and 1 × 1012 ions/cm2 and then compared their structural and optical properties by XRD, atomic force microscopy, photoluminescence, and UV-Vis spectroscopy before and after irradiation. The XRD spectra showed a broad hump around 2 ≈ 11.83° due to amorphous PMMA and other peaks corresponding to hexagonal structure of CdS nanocrystals in PMMA matrix. The photoluminescence spectra shows a broad peak at 530 nm corresponding to green emission due to Cu impurities in CdS. The UV-Vis measurement showed red shift in optical absorption and bandgap changed from 4.38–3.60 eV as the irradiation fluency increased with respect to pristine CdCuS nanocomposite polymer film.

  8. Binding of leachable components of polymethyl methacrylate (PMMA) and peptide on modified SPR chip

    Science.gov (United States)

    Szaloki, M.; Vitalyos, G.; Harfalvi, J.; Hegedus, Cs

    2013-12-01

    Many types of polymers are often used in dentistry, which may cause allergic reaction, mainly methyl methacrylate allergy due to the leachable, degradable components of polymerized dental products. The aim of this study was to investigate the interaction between the leachable components of PMMA and peptides by Fourier-transform Surface Plasmon Resonance (FT SPR). In our previous work binding of oligopeptides (Ph.D.-7 and Ph.D.-12 Peptide Library Kit) was investigated to PMMA surface by phage display technique. It was found that oligopeptides bounded specifically to PMMA surface. The most common amino acids were leucine and proline inside the amino acids sequences of DNA of phages. The binding of haptens, as formaldehyde and methacrylic acid, to frequent amino acids was to investigate on the modified gold SPR chip. Self assembled monolayer (SAM) modified the surface of gold chip and ensured the specific binding between the haptens and amino acids. It was found that amino acids bounded to modified SPR gold and the haptens bounded to amino acids by creating multilayer on the chip surface. By the application of phage display and SPR modern bioanalytical methods the interaction between allergens and peptides can be investigated.

  9. Physical and biological properties of the ion beam irradiated PMMA-based composite films

    Science.gov (United States)

    Shanthini, G. M.; Martin, Catherine Ann; Sakthivel, N.; Veerla, Sarath Chandra; Elayaraja, K.; Lakshmi, B. S.; Asokan, K.; Kanjilal, D.; Kalkura, S. Narayana

    2015-02-01

    Polymethyl methacrylate (PMMA) and PMMA-hydroxyapatite (PMMA-HAp) composite films, prepared by the solvent evaporation method were irradiated with 100 MeV Si7+ ions. Crystallographic, morphological and the functional groups of the pristine and irradiated samples were studied using glancing incident X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) respectively. SEM reveals the creation of pores, along with an increase in porosity and cluster size on irradiation. Decrease in crystalline nature and crystallite size with an increase in ion fluence was observed from GIXRD patterns. The surface roughness and the wettability of the material were also enhanced, which could favour the cell-material interaction. The irradiated samples adsorbed significantly greater amount of proteins than pristine. Also, irradiation does not produce any toxic byproducts or leachants, and maintains the viability of 3T3 cells. The response of the irradiated samples towards biomedical applications was demonstrated by the improved antimicrobial activity, haemocompatibility and cytocompatibility. Swift heavy ion irradiation (SHI) could be an effective tool to modify and engineer the surface properties of the polymers to enhance the biocompatibility.

  10. Development of hardened PVF : PMMA polyblend: effect of gamma and electron irradiation

    Indian Academy of Sciences (India)

    R Bajpai; N B Dhagat; R Katare; Pragyesh Agrawal; S C Datt

    2003-06-01

    Specimens of poly(vinyl formal) (PVF) : poly(methyl methacrylate) (PMMA) polyblends with different weight percentage ratios were subjected to gamma irradiation (1 to 50 Mrad) and electron irradiation (1 to 20 Mrad). The effect of irradiation on the strength of the blend specimens was studied by measuring the surface microhardness using a Vickers microhardness tester attached to a Carl Zeiss NU 2 Universal research microscope. Significant changes were observed in the Vickers microhardness number, $H_v$. The $H_v$ values of gamma irradiated specimens are found to be higher than the unirradiated specimens indicating an occurrence of radiational crosslinking. The maximum value of $H_v$ is obtained at the gamma radiation dose of 15 Mrad. In case of electron irradiation the radiational crosslinking is found to take place for the blend specimens having lower wt% content of PMMA (0 and 1 wt%) in PVF matrix. On the other hand degradation of polymeric system is observed for the blends having PMMA content more than 1 wt%. The maximum value of $H_v$ is obtained for all the blend specimens at the electron irradiation dose of 8 Mrad. The degree of crosslinking in polyblends due to gamma irradiation is found to be more than electron irradiation. The scissioning mechanism is found to predominate in the polyblend system in case of electron irradiation.

  11. Performance of a Novel PMMA Polymer Imaging Bundle for Field Acquisition and Wavefront Sensing

    Science.gov (United States)

    Richards, S. N.; Leon-Saval, S.; Goodwin, M.; Zheng, J.; Lawrence, J. S.; Bryant, J. J.; Bland-Hawthorn, J.; Norris, B.; Cvetojevic, N.; Argyros, A.

    2017-01-01

    Imaging bundles provide a convenient way to translate a spatially coherent image, yet conventional imaging bundles made from silica fibre optics typically remain expensive with large losses due to poor filling factors ( 40%). We present the characterisation of a novel polymer imaging bundle made from poly(methyl methacrylate) (PMMA) that is considerably cheaper and a better alternative to silica imaging bundles over short distances ( 1 m; from the middle to the edge of a telescope's focal plane). The large increase in filling factor (92% for the polymer imaging bundle) outweighs the large increase in optical attenuation from using PMMA (1 dB/m) instead of silica (10-3 dB/m). We present and discuss current and possible future multi-object applications of the polymer imaging bundle in the context of astronomical instrumentation including: field acquisition, guiding, wavefront sensing, narrow-band imaging, aperture masking, and speckle imaging. The use of PMMA limits its use in low-light applications (e.g., imaging of galaxies); however, it is possible to fabricate polymer imaging bundles from a range of polymers that are better suited to the desired science.

  12. Research on Continuous Injection Direct Rolling Process for PMMA Optical Plate

    Directory of Open Access Journals (Sweden)

    HaiXiong Wang

    2014-06-01

    Full Text Available Continuous injection direct rolling (CIDR combined intermittent injection and rolling process is a new technology for molding optical polymer plates with microstructured patterns; research on forming PMMA optical plates is an aspect of it in this paper. The equipment of CIDR process consists of plastic injection module, precision rolling module, and automatic coiling module. Based on the establishing mathematical CIDR models, numerical analysis was used to explode the distribution of velocity, temperature, and pressure in injection-rolling zone. The simulation results show that it is feasible to control the temperature, velocity, and injection-rolling force, so it can form polymer plate under certain process condition. CIDR experiment equipment has been designed and produced. PMMA optical plate was obtained by CIDR experiments, longitudinal thickness difference is 0.005 mm/200 mm, horizontal thickness difference is 0.02/200 mm, transmittance is 86.3%, Haze is 0.61%, and the difference is little compared with optical glasses. So it can be confirmed that CIDR process is practical to produce PMMA optical plates.

  13. Fabrication of microchannels on PMMA using a low power CO2 laser

    Science.gov (United States)

    Imran, Muhammad; Rahman, Rosly A.; Ahmad, Mukhtar; Akhtar, Majid N.; Usman, Arslan; Sattar, Abdul

    2016-09-01

    This study presents a cheap and quick method for the formation of microchannels on poly methyl methacrylate (PMMA). A continuous wave CO2 laser with a wavelength of 10.6 μm was used to inscribe periodic ripple structures on a PMMA substrate. A direct writing technique was employed for micromachining. As PMMA is very sensitive to such laser irradiations, a slightly low power CO2 laser was effective in inscribing such periodic structures. The results show that smooth and fine ripple structures can be fabricated by controlling the input laser parameters and interaction time of the laser beam. This direct laser writing technique is promising enough to prevent us from using complex optical arrangements. Laser power was tested starting from the ablation threshold and was gradually increased, together with the variation in scanning speed of the xy-translational stage, to observe the effects on the target surface in terms of depth and width of trenches. It was observed that the depth of the trenches increases on increasing the laser power, and the bulge formation on the outer sides of the trenches was also studied. It was evident that the formation of bulges across the trenches is dependent on the scanning speed and input laser power. The results depict that a focused laser beam with optimized parameters, such as controlling the scanning speed and laser power, results in fine, regular and tidy periodic structures.

  14. Synthesis and characterization of hybrid silica/PMMA nanoparticles and their use as filler in dental composites.

    Science.gov (United States)

    Canché-Escamilla, G; Duarte-Aranda, S; Toledano, M

    2014-09-01

    The effect of hybrid silica/poly(methylmethacrylate) (PMMA) nanoparticles on the properties of composites for dental restoration was evaluated. Hybrid nanoparticles with silica as core and PMMA as shell were obtained by a seeded emulsion polymerization process. Fourier transform infrared spectrum of the hybrid nanoparticles shows an intense peak at 1,730 cm(-1), corresponding to carbonyl groups (CO) of the ester. The thermal stability of the hybrid particles decreases with increasing amounts of PMMA and the residual mass at 700°C corresponds to the silica content in the hybrid particles. Composites were obtained by dispersing nanoparticles (silica or hybrid), as fillers, in a resin-bis glycidyl dimethacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) (40%/60% (w/w)). The paste was then placed in a mold and polymerized under light irradiation. During the preparation of the composites, with the hybrid nanoparticles, the monomers swell the PMMA shell and after photo-curing, a semi-interpenetrating network (semi-IPN) is obtained around the silica core. The properties of the composites, obtained using the hybrid nanoparticles, depend on the filler content and the amount of PMMA in the semi-IPN matrix. For composites with similar inorganic filler contents, the composites with low amounts of PMMA shell had higher modulus than those in which silica was used as the filler. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Preparation, characterization and performance of a novel PVDF/PMMA/TPU blend hollow fiber membrane for wastewater treatment.

    Science.gov (United States)

    Ma, C Y; Huang, J P; Xi, D L

    2012-01-01

    Polyvinylidene fluoride (PVDF)/polymethylmethacrylate (PMMA)/thermoplastic polyurethane (TPU) blend hollow fiber membranes were successfully prepared by the wet-spinning method with the loading of PMMA and TPU in a range of polymer concentrations varying from 0 to 20 wt% and at a total polymer concentration of 16 wt%. The influence of the addition of PMMA and TPU on the morphologies and the properties of such prepared membranes was investigated through FTIR-ATR, SEM, viscosity measurements, UF experiments and mechanical strength tests. Based on the experimental results, the compatibility of the PVDF, PMMA and TPU blend was best under the conditions of the PVDF-rich phase. The elongation at break of the membrane increased to a maximum of 146% with increase in the TPU concentration to 20 wt% in dope solution. The addition of PMMA increased the water permeation flux from 120 to 195 L/(m(2) h) initially. The flux then decreased when PMMA concentration was increased to over 10 wt%. The membranes obtained at optimized blending ratio were applied to the dyeing process wastewater filtration. During continuous filtration for 8 h, the flux was stabilized at about 20 L/(m(2) h) at 0.1 MPa. The reduction in COD(Cr), turbidity and color were about 63, 84 and 63% respectively.

  16. INTERFACIAL ADHESION AND MECHANICAL PROPERTIES OF PMMA-COATED CaCO3 NANOPARTICLE-REINFORCED PVC COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Xuehua Chen; Chunzhong Li; Shoufang Xu; Ling Zhang; Wei Shao; H. L. Du

    2006-01-01

    Polymethyl methacrylate (PMMA)-coated nano-CaCO3 particles were prepared by in-situ emulsion polymerization. The mechanical properties of nano-CaCO3 particles-reinforced PVC were investigated using an AG-2000A universal testing machine and an XJU-2.75 izod impact tester; interfacial adhesion between CaCO3 nanoparticles and PVC matrix by SEM, and structure of PMMA coated on the surface of CaCO3 by FTIR and 1H-NMR. The results indicate that the PMMA coated on the nano CaCO3 particles consists mainly of syndiotactic structure, and their three tacticity contents were rr 52.8%, mm 7.3% and mr 39.9%, respectively. The interfacial adhesion between CaCO3 nanoparticles and PVC matrix was significantly improved when the CaCO3 nanoparticles were coated with PMMA, which led to increased Young's moduli and tensile strengths of the PMMA-coated CaCO3/PVC composites. The izod impact strengths of the composites were strongly affected by the PMMA coating thickness and increased significantly with increasing the volume fraction of CaCO3 filler in the composites.

  17. Preparation of PMMA/SBA-15 Composites Via In-Situ Emulsion Polymerization%原位乳液聚合法制备PMMA/SBA-15复合材料

    Institute of Scientific and Technical Information of China (English)

    宋程; 张发爱; 余彩莉

    2011-01-01

    Poly (methyl methacrylate) (PMMA)/SBA-15 (0,1% ,2. 5% ,5% ) composite materials are prepared with different loadings of mesoporous molecular sieve SBA-15 via in-situ emulsion polymerization, and the properties of as-prepared composite emulsions are investigated by infrared spectroscopy (IR) and X-ray diffraction (XRD).The results show that the PMMA/SBA-15 composites are prepared successfully. The composite emulsions demonstrate high monomer conversion and coagulum, low viscosity, relatively large particle size, and wide range of distribution. The PMMA/SBA-15 composite film exhibites greater storage modulus and higher Young's modulus when compared with pure PMMA (especially, the composite with 2. 5% SBA -15 displayed the greatest storage and Young's modulus). The glass transition temperature of the composites increases with the increase of mesoporous silica loading. TGA confirms that the thermal stabilities of PMMA/SBA-15 composites are not influenced apparently.%采用原位乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA) /SBA-15介孔复合材料,研究了不同用量介孔硅SBA-15(0、1%、2.5%、5%)对PMMA/SBA-15介孔复合材料性能的影响.红外光谱(IR)和X射线衍射(XRD)分析表明成功制备了PMMA/SBA-15复合材料.以乳液聚合法制备的PMMA/SBA-15复合材料具有较高的单体转化率和固体含量,随着SBA-15用量的增加,聚合过程中凝聚率增大、粘度减小,复合乳液具有较大的粒径及更宽的粒径分布.动态力学分析(DMA)测试表明:PMMA/SBA-15复合材料储能模量和杨氏模量明显增大,且在SBA-15用量为2.5%时复合材料模量最高.差示扫描量热( DSC)测试表明:随着SBA-15用量增加,复合材料玻璃化温度提高.热重分析(TGA)结果证实复合材料热稳定性没有明显变化.

  18. Modifications in optical and structural properties of PMMA/PCTFE blend films as a function of PCTFE concentration

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, J., E-mail: jtripathi00@gmail.com [Dept. of Physics, ISLE, IPS Academy, Indore (India); Sharma, A. [Dept. of Physics, Manipal University Jaipur, Jaipur (India); Tripathi, S. [UGC-DAE Consortium for Scientific Research, Indore (India); Bisen, R. [Dept. of Physics, ISLE, IPS Academy, Indore (India); Agrawal, A. [Dept. of Elect. and Commun., Global Engineering College, Jabalpur (India)

    2017-06-15

    The poly (methyl methacrylate) (PMMA) polymer blend films were prepared by solution casting method with varying PolyChloroTriFluoroEthylene (PCTFE) concentrations (1–5 wt %). The crystallinity, bonding behavior and disorder in the films were investigated with X-ray diffraction (XRD), Fourier transform infrared (FTIR), UV–visible and ellipsometry techniques, while surface morphology was studied using Atomic force microscopy (AFM). The nanocrystalline nature of PMMA is seen to be preserved in the blends although there are clear indications of bond modifications. The addition of PCTFE results in the improvement of overall crystallinity of the films via the interaction among PMMA and degraded PCTFE molecules when the films are casted from diluted solutions. In agreement, corresponding disorder in terms of Urbach energy shows a decreasing trend upon inclusion of more and more PCTFE molecules. Micro-Raman spectra are dominated by fluorescence background, which is proposed as arising from degraded PCTFE. Supporting this, FTIR spectra also shows modifications in bonding as a function of PCTFE percentage, but this bond modification is not enough to produce refractive index variation in the sample, which is dominated by the host PMMA contribution for all the PCTFE concentrations. The study suggests the useful range of PCTFE concentration in which PMMA host properties can be modified for optimizing optical and structural properties without much degradation of PCTFE. - Highlights: • PMMA blend films with varying PCTFE concentrations (1–5 wt%) were prepared. • Nanocrystalline nature of PMMA is preserved in spite of bond modifications. • Addition of PCTFE results in improvement of overall crystallinity of the films. • Urbach energy shows a decreasing Disorder upon inclusion of more PCTFE molecules. • FTIR spectra show bond modifications without changing refractive index.

  19. FABRICATION AND CHARACTERIZATION OF ORGANIC THIN FILMS WITH NANO—STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    TakashiH,Noritaka; ChenGuorong; 等

    2002-01-01

    A novel method of thin film formation of organic materials with nano-strucure has been successfully developed by using vacuum technique is proposed. The diarylethene(C18H18N2S2)was selected as a model compound for the evaluation of this method.Polymer,we found that the tendency of dye dispersion into the polymer is as follows:PC>PBzMA>PMMA>PHPMA,where no dispersion is observed for PHPMA under the condition of 115℃ for 24 hours ,Thin film of polymer alloy composed of PMMA and polystylene(PS) was loaded into a glass ample with diarylethene,and treated for three days at 100℃,Dispersed state of the dye was evaluated by transmission electron microscope,and concluded that the dye is distributed only in PS domains selectively.Photochromic properties of the PS domain will be evaluated by using a scanning nearfield optical microscope.

  20. Isomerization and optical bistability of DR1 doped organic-inorganic sol-gel thin film

    Science.gov (United States)

    Gao, Tianxi; Que, Wenxiu; Shao, Jinyou

    2015-10-01

    To investigate the isomerization process of the disperse red 1 (DR1) doped TiO2/ormosil thin film, both the photo-isomerization and the thermal isomerization of the thin films were observed as a change of the absorption spectrum. Under a real-time heat treatment, the change of the linear refractive index shows a thermal stable working temperature range below Tg. The optical bistability (OB) effect of the DR1 doped thin films based on different matrices was studied and measured at a wavelength of 532 nm. Results indicate that the TiO2/ormosils based thin film presents a better OB-gain than that of the poly (methyl methacrylate) (PMMA) based thin film due to its more rigid network structure. Moreover, it is also noted that higher titanium content is helpful for enhancing the OB-gain of the as-prepared hybrid thin films.

  1. Theoretical and experimental investigations on linear and nonlinear optical response of metal complexes doped PMMA films

    Science.gov (United States)

    Praveen, P. A.; Babu, R. Ramesh; Ramamurthi, K.

    2017-02-01

    Metal organic complexes, diaceto bis benzimidazole cobalt(II) and diaceto bis benzimidazole copper(II), are synthesized by a simple chemical route. The synthesized powders are doped in PMMA with 1, 3, 5 wt% and deposited as free standing films of thickness  ∼1 μm. For theoretical simulation, metal organic complex (MOC) embedded into the PMMA matrix is subjected to polarizability and hyperpolarizability calculations using the PM6 algorithm in MOPAC2012 package. It is found that the minimum interaction distance between PMMA and MOC is about 34 nm and does not vary with respect to the dopant. The copper complex shows higher interaction energy with the polymer matrix than the cobalt complex. Time dependent Hartree Fock approach is used to calculate the α, β and γ values for static, 0.25 and 0.5 eV energies; the cobalt complex shows higher polarizability and hyperpolarizability than the copper complex. Experimentally, the optical absorption, thermo-optic coefficient, nonlinear absorption coefficient and nonlinear refractive index of the samples are determined. The thermo-optic coefficients of the samples are seen to increase with increasing dopant concentration. From open aperture Z-scan studies the films are found to exhibit reverse saturable absorption behaviour, and from the closed aperture Z-scan all samples are found to exhibit self-focusing effects. The calculated third order susceptibility is in the order of 10‑5 esu. The optical limiting properties are studied at 650 nm using a 20 mW laser and all the samples are found to exhibit good optical limiting in the operating wavelength.

  2. Effect of vacuum-treatment on deformation properties of PMMA bone cement.

    Science.gov (United States)

    Zivic, Fatima; Babic, Miroslav; Grujovic, Nenad; Mitrovic, Slobodan; Favaro, Gregory; Caunii, Mihaela

    2012-01-01

    Deformation behavior of polymethyl methacrylate (PMMA) bone cement is explored using microindentation. Two types of PMMA bone cement were prepared. Vacuum treated samples were subjected to the degassing of the material under vacuum of 270 mbar for 35 s, followed by the second degassing under vacuum of 255 mbar for 35 s. Air-cured samples were left in ambient air to cool down and harden. All samples were left to age for 6 months before the test. The samples were then subjected to the indentation fatigue test mode, using sharp Vickers indenter. First, loading segment rise time was varied in order to establish time-dependent behavior of the samples. Experimental data showed that viscous part of the deformation can be neglected under the observed test conditions. The second series of microindentation tests were realized with variation of number of cycles and indentation hardness and modulus were obtained. Approximate hardness was also calculated using analysis of residual impression area. Porosity characteristics were analyzed using CellC software. Scanning electron microscopy (SEM) analysis showed that air-cured bone cement exhibited significant number of large voids made of aggregated PMMA beads accompanied by particles of the radiopaque agent, while vacuum treated samples had homogeneous structure. Air-cured samples exhibited variable hardness and elasticity modulus throughout the material. They also had lower hardness values (approximately 65-100 MPa) than the vacuum treated cement (approximately 170 MPa). Porosity of 5.1% was obtained for vacuum treated cement and 16.8% for air-cured cement. Extensive plastic deformation, microcracks and craze whitening were produced during indentation of air-cured bone cement, whereas vacuum treated cement exhibited no cracks and no plastic deformation.

  3. Erosion of FEP Teflon and PMMA by VUV radiation and hyperthermal O or Ar atoms.

    Science.gov (United States)

    Zhang, Jianming; Lindholm, Ned F; Brunsvold, Amy L; Upadhyaya, Hari P; Minton, Timothy K; Tagawa, Masahito

    2009-03-01

    A combination of beam-surface-scattering, quartz-crystal-microbalance, and surface-recession experiments was conducted to study the effects of various combinations of O atoms [in the O((3)P) ground state], Ar atoms, and vacuum ultraviolet (VUV) light on fluorinated ethylene-propylene copolymer (FEP) Teflon and poly(methyl methacrylate) (PMMA). A laser-breakdown source was used to create hyperthermal beams containing O and O(2) or Ar. A D(2) lamp provided a source of VUV light. O atoms with 4 eV of translational energy or less did not react with a pristine FEP Teflon surface. Volatile O-containing reaction products were observed when the O-atom energy was higher than 4.5 eV, and the signal increased with the O-atom energy. Significant erosion of FEP Teflon ( approximately 20% of Kapton H) was observed when it was exposed to the hyperthermal O/O(2) beam with an average O-atom energy of 5.4 eV. FEP Teflon and PMMA that were exposed to VUV light alone exhibited much less mass loss. Collision-induced dissociation by hyperthermal Ar atoms also caused mass loss, similar in magnitude to that caused by VUV light. There were no observed synergistic effects when VUV light or Ar bombardment was combined with O/O(2) exposure. For both FEP Teflon and PMMA, the erosion yields caused by simultaneous exposure to O/O(2) and either VUV light or Ar atoms could be approximately predicted by adding the erosion yield caused by O/O(2), acting individually, to the erosion yield caused by the individual action of either VUV light or Ar atoms.

  4. Evaluation of the tapered PMMA fiber sensor response due to the ionic interaction within electrolytic solutions

    Science.gov (United States)

    Batumalay, M.; Rahman, H. A.; Kam, W.; Ong, Y. S.; Ahmad, F.; Zakaria, R.; Harun, S. W.; Ahmad, H.

    2014-01-01

    A tapered plastic multimode fiber (PMMA) optical sensor is proposed and demonstrated for continuous monitoring of solutions based on different concentration of sodium chloride and glucose in deionized water The tapered PMMA fiber was fabricated using an etching method involving deionized water and acetone to achieve a waist diameter and length of 0.45 mm and 10 mm, respectively, and was used to investigate the effect of straight, U-shape, and knot shape against concentration for both sodium chloride and glucose. The results show that there is a strong dependence of the electrolytic and non-electrolytic nature of the chemical solutions on the sensor output. It is found that the sensitivity of the sodium chloride concentration sensor with the straight tapered fiber probe was 0.0023 mV/%, which was better than the other probe arrangements of U-shape and knot. Meanwhile, the glucose sensor performs with the highest sensitivity of 0.0026 mV/wt % with the knot-shaped tapered fiber probe. In addition, a tapered PMMA probe which was coated by silver film was fabricated and demonstrated using calcium hypochlorite (G70) solution. The working mechanism of such a device is based on the observed increment in the transmission of the sensor that is immersed in solutions of higher concentration. As the concentration varies from 0 ppm to 6 ppm, the output voltage of the sensor increases linearly from 3.61 mV to 4.28 mV with a sensitivity of 0.1154 mV/ppm and a linearity of more than 99.47%. The silver film coating increases the sensitivity of the proposed sensor due to the effective cladding refractive index, which increases with the coating and thus allows more light to be transmitted from the tapered fiber.

  5. The improvement of the mechanical properties of PMMA denture base by Al2O3 particles with nitrile rubber

    Science.gov (United States)

    Alhareb, Ahmed Omran; Akil, Hazizan Md; Ahmad, Zainal Arifin

    2017-07-01

    Poly methyl methacrylate (PMMA) is mostly used for fabrication of denture base by heat-curing technique. Therefore, the purpose of this study is to investigate the effect of Al2O3 filler as toughening particles together with nitrile butadiene rubber (NBR) particles as impact modifier were used to reinforce PMMA denture base materials on the impact strength (IS) and fracture toughness (KIC). PMMA powder was mixed with liquid methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent. The powder components are PMMA, benzoyl peroxide, NBR (5, 7.5 and 10 wt%), and Al2O3 filler (5 wt%) treated by silane. The liquid components are 90% of methyl methacrylate and 10 % ethylene glycol dimethacryate. FTIR analyses confirmed that the Al2O3 filler was successfully treated with silane as coupling agent. The morphology of fracture surfaces was characterized using field emission scanning electron microscopy (FESEM). The results shown that IS and KIC improved significantly when using treated the Al2O3 filler. IS has increased to 56% (8.26 KJ/m2) and 73% (2.77 MPa.m1/2) for KIC when treated Al2O3 filler compared to unreinforced PMMA matrix. Statistical analyses of data results were significantly improved (P<0.05) when using 7.5 wt% NBR with treated Al2O3 filler compared to other the compositions.

  6. A novel approach for the preparation of PMMA-PDMS core-shell particles with PDMS in the shell

    Energy Technology Data Exchange (ETDEWEB)

    Deng Xiaobo [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Liu Bailing [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)]. E-mail: blliuchem@hotmail.com; Cao Shunsheng [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Luo Rong [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Chen Hualin [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)

    2007-03-30

    The core/shell particles consisting of polymethyl methacrylate (PMMA) core and polydimethylsiloxane (PDMS) shell via 3-(methacryloxypropyl)-trimethoxysilane (MPS) as the medium to link the core and shell were prepared in our present study by successive seeding polymerization under kinetically controlled conditions and were characterized by FT-IR, particle size analyzer, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The picture of optical microscope showed the clear form of PDMS-0 and PDMS-40 (the content of PDMS in the particles), which approached to monodispersed distribution. Compared with the PMMA microspheres, PDMS-40 presented an evident core/shell structure through the observation of TEM. Additionally, the study of XPS revealed that PDMS could be grafted onto the surface of PMMA particles and the atomic ratio of C/Si on the surface of PDMS-40 was very close to the ratio of C/Si in the molecule of PDMS. The surface properties of the films produced from the core/shell microspheres also were investigated by contact angle method, contrast with the homopolymer of PMMA, the core/shell particles were more effective to form hydrophobic surface and the water repellency on the surface would be better than that of PMMA.

  7. Effect of plasma fluorination variables on the deposition and growth of partially fluorinated polymer over PMMA films

    Directory of Open Access Journals (Sweden)

    Giovana da Silva Padilha

    2013-01-01

    Full Text Available In this work, an investigation was made of the modification of film surface of Poly(methylmethacrylate (PMMA using the plasma polymerization technique. PMMA films 10 µm thick were obtained by Spin-Coating starting from a chloroform solution (15.36% w/w. The films were exposed to the plasma of CHF3 at different gas pressures and exposure times to increase the thickness of fluorinated polymers onto PMMA films. The plasma fluorinated optical films were characterized by gravimetry, FTIR-ATR, contact angle of wetting, SEM and AFM. The surface fluorination of PMMA films can be inferred by the increase in contact angle under all experimental conditions, and confirmed with FTIR-ATR analysis. Gravimetry showed an increase of the fluorinated polymer layer over PMMA films, being 1.55 µm thick at 0.7 torr and 40 minutes of plasma exposure. The SEM analysis showed a well-defined layer of fluorinated polymer, with fluorine being detected in the EDS analysis. The film roughness for the fluorinated polymers was around of 200 Å, quite satisfactory for a 1.55 µm cladding.

  8. PMMA Third-Body Wear after Unicondylar Knee Arthroplasty Decuples the UHMWPE Wear Particle Generation In Vitro

    Directory of Open Access Journals (Sweden)

    Alexander Christoph Paulus

    2015-01-01

    Full Text Available Introduction. Overlooked polymethylmethacrylate after unicondylar knee arthroplasty can be a potential problem, since this might influence the generated wear particle size and morphology. The aim of this study was the analysis of polyethylene wear in a knee wear simulator for changes in size, morphology, and particle number after the addition of third-bodies. Material and Methods. Fixed bearing unicondylar knee prostheses (UKA were tested in a knee simulator for 5.0 million cycles. Following bone particles were added for 1.5 million cycles, followed by 1.5 million cycles with PMMA particles. A particle analysis by scanning electron microscopy of the lubricant after the cycles was performed. Size and morphology of the generated wear were characterized. Further, the number of particles per 1 million cycles was calculated for each group. Results. The particles of all groups were similar in size and shape. The number of particles in the PMMA group showed 10-fold higher values than in the bone and control group (PMMA: 10.251×1012; bone: 1.145×1012; control: 1.804 × 1012. Conclusion. The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology. PMMA third-bodies generated tenfold elevated particle numbers. This could favor an early aseptic loosening.

  9. Recent developments of Bragg gratings in PMMA and TOPAS polymer optical fibers

    DEFF Research Database (Denmark)

    Webb, David; Kyriacos, Kalli; Carroll, Karen

    We report on the temperature response of FBGs recorded in pure PMMA and TOPAS holey fibers. The gratings are fabricated in the near IR using a cw He-Cd laser operating at 325nm. The room temperature grating response is non-linear and characterised by quadratic behaviour for temperatures from room......, leading to very good fibre drawing properties. Furthermore, although Topas is chemically inert and biomolecules do not readily bind to its surface, treatment with Antraquinon and subsequent UV activation allows sensing molecules to be deposited in well defined spatial locations. When combined with grating...

  10. Stretching DNA in polymer nanochannels fabricated by thermal imprint in PMMA

    DEFF Research Database (Denmark)

    Thamdrup, Lasse Højlund; Klukowska, A.; Kristensen, Anders

    2008-01-01

    ) using a 4 inch diameter two-level hybrid stamp. The fluidic structures were sealed using thermal polymer fusion bonding. The stamp has nanometer-and micrometer-sized protrusions defined in a thermally grown SiO2 layer and the sol - gel process derived duromeric hybrid polymer Ormocomp, respectively....... The stamp is compatible with molecular vapor deposition ( MVD), used for applying a durable chlorosilane based antistiction coating, and allows for imprint up to a temperature of 270 degrees C. The extension of YOYO-1 stained T4 GT7 bacteriophage DNA inside the PMMA nanochannels has been experimentally...

  11. XUV-laser induced ablation of PMMA with nano-, pico-, and femtosecond pulses

    Energy Technology Data Exchange (ETDEWEB)

    Juha, L. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic)]. E-mail: juha@fzu.cz; Bittner, M. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic); Chvostova, D. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic)] (and others)

    2005-06-15

    For conventional wavelength (UV-vis-IR) lasers delivering radiation energy to the surface of materials, ablation thresholds, etch (ablation) rates, and the quality of ablated structures often differ dramatically between short (typically nanosecond) and ultrashort (typically femtosecond) pulses. Various very short-wavelength ({lambda} < 100 nm) lasers, emitting pulses with durations ranging from {approx}10 fs to {approx}1 ns, have recently been placed into routine operation. This has facilitated the investigation of how ablation characteristics depend on the pulse duration in the XUV spectral region. Ablation of poly(methyl methacrylate) (PMMA) induced by three particular short-wavelength lasers emitting pulses of various durations, is reported in this contribution.

  12. Use of Lead (II) Sulfide Nanoparticles as Stabilizer for PMMA Exposed to Gamma Irradiation

    OpenAIRE

    Garcia,Olga Pinheiro; Albuquerque,Marília Cordeiro Carneiro de; Aquino, Kátia Aparecida da Silva; Araujo,Patricia Lopes Barros; Araujo,Elmo Silvano de

    2015-01-01

    Lead (II) sulfide (PbS) were synthesized by sonochemical method and crystals with cubic structure exhibit aggregated nanoparticles with size in the range of 50-100 nm. Commercial Poly(methyl methacrylate) (PMMA) containing the PbS nanoparticles (PbS-NP) exposed to gamma irradiation were investigated and both the viscosity-average molar mass (Mv) and degradation index (DI) values were measured. Ours results showed decreases in molar mass when the systems were gamma irradiated, i. e., random sc...

  13. Precise Hole Drilling in PMMA Using 1064 nm Diode Laser CNC Machine

    Directory of Open Access Journals (Sweden)

    Jinan A. Abdulnabi

    2011-01-01

    Full Text Available This paper represents the outcome of efforts that intended to achieve laser hole drilling execution in polymethylmethacrylate (PMMA of 2.5 mm thickness using 1064 nm diode laser of 5 W output power. Different laser beam powers, exposure time, and positions of the laser spot were taken into consideration with respect to the workpiece. The workpieces were tested in the existence of low-pressure assist gas (20–60 mmHg of air. The experimental results were supported by the predicted results of the analytical model.

  14. Precise Hole Drilling in PMMA Using 1064 nm Diode Laser CNC Machine

    OpenAIRE

    Abdulnabi, Jinan A.; Thaier A. Tawfiq; Anwaar A. Al-Dergazly; Ziad A. Taha; Khalil I. Hajim

    2011-01-01

    This paper represents the outcome of efforts that intended to achieve laser hole drilling execution in polymethylmethacrylate (PMMA) of 2.5 mm thickness using 1064 nm diode laser of 5 W output power. Different laser beam powers, exposure time, and positions of the laser spot were taken into consideration with respect to the workpiece. The workpieces were tested in the existence of low-pressure assist gas (20–60 mmHg of air). The experimental results were supported by the predicted results of ...

  15. Fast bragg grating inscription in PMMA polymer optical fibres: Impact of thermal pre-treatment of preforms

    DEFF Research Database (Denmark)

    Marques, Carlos A. F.; Pospori, Andreas; Demirci, Gökhan

    2017-01-01

    In this work, fibre Bragg gratings (FBGs) were inscribed in two different undoped poly- (methyl methacrylate) (PMMA) polymer optical fibres (POFs) using different types of UV lasers and their inscription times, temperature and strain sensitivities are investigated. The POF Bragg gratings (POFBGs......) were inscribed using two UV lasers: a continuous UV HeCd @325 nm laser and a pulsed UV KrF @248 nm laser. Two PMMA POFs are used in which the primary and secondary preforms (during the two-step drawing process) have a different thermal treatment. The PMMA POFs drawn in which the primary or secondary...... preform is not specifically pre-treated need longer inscription time than the fibres drawn where both preforms have been pre-annealed at 80 °C for 2 weeks. Using both UV lasers, for the latter fibre much less inscription time is needed compared to another homemade POF. The properties of a POF fabricated...

  16. Rheological studies of PMMA-PVC based polymer blend electrolytes with LiTFSI as doping salt.

    Directory of Open Access Journals (Sweden)

    Chiam-Wen Liew

    Full Text Available In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate (PMMA and poly (vinyl chloride (PVC is varied, whereas in the second system, the composition of PMMA-PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl imide (LiTFSI with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of G' and G'' is absent. Linear viscoelastic (LVE range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases.

  17. Synthesis and characterization of PMMA/Al2O3 composite particles by in situ emulsion polymerization

    Institute of Scientific and Technical Information of China (English)

    Hui Liu; Hongqi Ye; Tianquan Lin; Tao Zhou

    2008-01-01

    In order to improve its dispersibility, superfine alumina (Al2O3) was encapsulated with poly (methyl methacrylate) (PMMA) by in situ emulsion polymerization. It was found that only when the concentration of sodium dodecyl sulfate (SDS) was much higher than its critical micelle concentration, could PMMA/Al2O3 composite particles with high percentage of grafting (PG) be prepared. The same results were obtained between the experimental and stoichiometric amounts of tris (dodecylbenzenesulfonate) isopropoxide (NDZ), indicating that single-molecule-layer adsorption had taken place between NDZ and Al2O3. Analysis using FTIR. TEM and XPS showed that PMMA/Al2O3 composite particles with core-shell structure had been successfully synthesized by in sire emulsion polymerization. Compared to Al2O3, thermal stability and dispersibility of the composite particles showed marked improvement.

  18. Compatibility and thermal stability studies on plasticized PVC/PMMA blend polymer electrolytes complexed with different lithium salts

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2005-03-01

    Full Text Available The lithium salt (x (X= LiAsF6, LiPF6, LiN(C2F5SO22 , LiN(CF3SO22, LiBF4 was complexed with a host of poly(vinyl chloride (PVC/ poly(methyl methacrylate (PMMA blend polymer and plasticized with a combination of ethylene carbonate (EC and propylene carbonate(PC. The polymer electrolyte films were prepared for constant PVC/PMMA blend ratio. The electrochemical stability and thermal stability of the solid polymer electrolytes were reported. The role of PMMA to the phenomena occurring at the interface between the electrolyte and the lithium metal electrode was explored.

  19. Using low-contrast negative-tone PMMA at cryogenic temperatures for 3D electron beam lithography.

    Science.gov (United States)

    Schnauber, Peter; Schmidt, Ronny; Kaganskiy, Arsenty; Heuser, Tobias; Gschrey, Manuel; Rodt, Sven; Reitzenstein, Stephan

    2016-05-13

    We report on a 3D electron beam lithography (EBL) technique using polymethyl methacrylate (PMMA) in the negative-tone regime as a resist. First, we briefly demonstrate 3D EBL at room temperature. Then we concentrate on cryogenic temperatures where PMMA exhibits a low contrast, which allows for straightforward patterning of 3D nano- and microstructures. However, conventional EBL patterning at cryogenic temperatures is found to cause severe damage to the microstructures. Through an extensive study of lithography parameters, exposure techniques, and processing steps we deduce a hypothesis for the cryogenic PMMA's structural evolution under electron beam irradiation that explains the damage. In accordance with this hypothesis, a two step lithography technique involving a wide-area pre-exposure dose slightly smaller than the onset dose is applied. It enables us to demonstrate a >95% process yield for the low-temperature fabrication of 3D microstructures.

  20. Self-healing properties of 1-amino, 2,4-dibromo anthraquinone dye doped in PMMA polymer

    CERN Document Server

    Dhakal, Prabodh

    2016-01-01

    We used fluorescence spectroscopic measurements as a probe to study the self-healing properties of anthraquinone derivative molecules doped in poly(methyl methacrylate) (PMMA). 2,4-dibromo anthraquinone dye doped in PMMA recovers after photodegradation. Its dynamics differs from other anthraquinone derivative molecules. This could be due to the relatively heavier bromine atom attached to one of the carbon atoms of the benzene ring. In this paper, we will discuss the self-healing properties of 2,4-dibromo anthraquinone doped in PMMA matrix. We also tested the correlated chromophore domain model (CCrDM) and have characterized the self-healing properties by determining the CCrDM parameters. We also estimated the self-absorption of fluorescence signal by the dye molecule without which the analysis of the self-recovery of the molecule would be incomplete.

  1. Synthesis and Characterization of the in Situ Bulk Polymerization of PMMA Containing Graphene Sheets Using Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Mohammad A. Aldosari

    2013-03-01

    Full Text Available Polymethylmethacrylate–graphene (PMMA/RGO nanocomposites were prepared via in situ bulk polymerization using two different preparation techniques. In the first approach, a mixture of graphite oxide (GO and methylmethacrylate monomers (MMA were polymerized using a bulk polymerization method with a free radical initiator. After the addition of the reducing agent hydrazine hydrate (HH, the product was reduced via microwave irradiation (MWI to obtain R-(GO-PMMA composites. In the second approach, a mixture of graphite sheets (RGO and MMA monomers were polymerized using a bulk polymerization method with a free radical initiator to obtain RGO-(PMMA composites. The composites were characterized by FTIR, 1H-NMR and Raman spectroscopy and XRD, SEM, TEM, 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.

  2. Structural, thermal, optical properties and cytotoxicity of PMMA/ZnO fibers and films: Potential application in tissue engineering

    Science.gov (United States)

    Balen, Rodrigo; da Costa, Wilian Vidotto; de Lara Andrade, Jéssica; Piai, Juliana Francis; Muniz, Edvani Curti; Companhoni, Mychelle Vianna; Nakamura, Tânia Ueda; Lima, Sandro Marcio; da Cunha Andrade, Luis Humberto; Bittencourt, Paulo Rodrigo Stival; Hechenleitner, Ana Adelina Winkler; Pineda, Edgardo Alfonso Gómez; Fernandes, Daniela Martins

    2016-11-01

    Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The surfaces of the fibers exhibited greater hydrophobicity, compared to the films, with contact angles of around 120° and 94°, respectively. PMMA films containing ZnO exhibited higher thermal stability than the pure polymer, while the corresponding fibers did not show any changes in thermal stability. The dispersion of the ZnO NPs at the surface and in the bulk of the nanocomposites appeared to be relatively homogeneous. ZnO improved the optical properties of the PMMA, with an intense absorption band near 370 nm observed for all the nanocomposites, which also exhibited luminescence with emission in the near-UV region, both attributed to ZnO. Biological tests demonstrated that fibers and films with up to 1% of ZnO exhibited good performance in the proliferation of fibroblast cells, indicating their potential for applications in tissue engineering. The fibers provided higher cell viability than the films, presumably due to their greater surface area and/or more suitable surface morphology. Nanocomposites with 15% ZnO inhibited cell proliferation, due to the cytotoxicity of the ZnO NPs. Although several applications of PMMA have been suggested by biomedical researchers, until now there have been no reports on the specific uses of fibers and films of PMMA/ZnO nanocomposites as scaffolds for fibroblast cell proliferation.

  3. Temperature-controlled transparent-film heater based on silver nanowire-PMMA composite film.

    Science.gov (United States)

    He, Xin; Liu, A'lei; Hu, Xuyang; Song, Mingxia; Duan, Feng; Lan, Qiuming; Xiao, Jundong; Liu, Junyan; Zhang, Mei; Chen, Yeqing; Zeng, Qingguang

    2016-11-25

    We fabricated a high-performance film heater based on a silver nanowire and polymethyl methacrylate (Ag NW-PMMA) composite film, which was synthesized with the assistance of mechanical lamination and an in situ transfer method. The films exhibit excellent conductivity, high figure of merit, and strong adhesion of percolation network to substrate. By controlling NW density, we prepared the films with a transmittance of 44.9-85.0% at 550 nm and a sheet resistance of 0.13-1.40 Ω sq(-1). A stable temperature ranging from 130 °C-40 °C was generated at 3.0 V within 10-30 s, indicating that the resulting film heaters show a rapid thermal response, low driving voltage and stable temperature recoverability. Furthermore, we demonstrated the applications of the film heater in defrosting and a physical therapeutic instrument. A fast defrosting on the composite film with a transmittance of 88% was observed by applying a 9 V driving voltage for 20 s. Meanwhile, we developed a physical therapeutic instrument with two modes of thermotherapy and electronic-pulse massage by using the composite films as two electrodes, greatly decreasing the weight and power consumption compared to a traditional instrument. Therefore, Ag NW-PMMA film can be a promising candidate for diversified heating applications.

  4. Temperature-controlled transparent-film heater based on silver nanowire-PMMA composite film

    Science.gov (United States)

    He, Xin; Liu, A.'lei; Hu, Xuyang; Song, Mingxia; Duan, Feng; Lan, Qiuming; Xiao, Jundong; Liu, Junyan; Zhang, Mei; Chen, Yeqing; Zeng, Qingguang

    2016-11-01

    We fabricated a high-performance film heater based on a silver nanowire and polymethyl methacrylate (Ag NW-PMMA) composite film, which was synthesized with the assistance of mechanical lamination and an in situ transfer method. The films exhibit excellent conductivity, high figure of merit, and strong adhesion of percolation network to substrate. By controlling NW density, we prepared the films with a transmittance of 44.9-85.0% at 550 nm and a sheet resistance of 0.13-1.40 Ω sq-1. A stable temperature ranging from 130 °C-40 °C was generated at 3.0 V within 10-30 s, indicating that the resulting film heaters show a rapid thermal response, low driving voltage and stable temperature recoverability. Furthermore, we demonstrated the applications of the film heater in defrosting and a physical therapeutic instrument. A fast defrosting on the composite film with a transmittance of 88% was observed by applying a 9 V driving voltage for 20 s. Meanwhile, we developed a physical therapeutic instrument with two modes of thermotherapy and electronic-pulse massage by using the composite films as two electrodes, greatly decreasing the weight and power consumption compared to a traditional instrument. Therefore, Ag NW-PMMA film can be a promising candidate for diversified heating applications.

  5. PMMA-based ophthalmic contact lens for vision correction of strabismus

    Science.gov (United States)

    Asgharzadeh Shishavan, Amir; Nordin, Leland; Tjossem, Paul; Abramoff, Michael D.; Toor, Fatima

    2016-09-01

    In this work we present the design of a novel ophthalmic prismatic contact lens to correct for strabismus. Strabismus, colloquially called "crossed-eyes" or "wall eyes," is a condition in which the eyes are not properly aligned with each other. To our knowledge there are no contact lenses that allow for strabismus correction. To address this, we have designed a poly methyl methacrylate (PMMA) based prismatic correction contact lens. Therefore, we modeled a Fresnel lens with the appropriate optical properties and a human eye in COMSOL Multiphysics Ray Optics module. Our first design was created by mapping Fresnel lenses onto the curved surface of the eye, the focus of light on retina was suboptimal. Next we determined two more potential solutions and improved the light focus on the retina but there were still some issues. A small fraction of light ( 5%) diverged and could not be focused. Due to dispersive characteristic of PMMA, chromatic aberration was present. We will use our ray optics solution and convert into a metasurface nanophotonic lens that has the identical behavior and mitigates the issues related with prismatic lens.

  6. Dosimetric study of thermoluminescent detectors in clinical photon beams using liquid water and PMMA phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, Luciana C., E-mail: lmatsushima@ipen.br [Gerencia de Metrologia das Radiacoes (GMR) - Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, CEP: 05508-000, Sao Paulo, SP (Brazil); Veneziani, Glauco R. [Gerencia de Metrologia das Radiacoes (GMR) - Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, CEP: 05508-000, Sao Paulo, SP (Brazil); Sakuraba, Roberto K. [Gerencia de Metrologia das Radiacoes (GMR) - Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Av. Prof. Lineu Prestes, 2242, Cidade Universitaria, CEP: 05508-000, Sao Paulo, SP (Brazil); Sociedade Beneficente Israelita Brasileira - Hospital Albert Einstein (HAE), Avenida Albert Einstein, 665, Morumbi, CEP: 05652-000, Sao Paulo, SP (Brazil); Cruz, Jose C. da [Sociedade Beneficente Israelita Brasileira - Hospital Albert Einstein (HAE), Avenida Albert Einstein, 665, Morumbi, CEP: 05652-000, Sao Paulo, SP (Brazil)

    2012-07-15

    The purpose of this study was the dosimetric evaluation of thermoluminescent detectors of calcium sulphate doped with dysprosium (CaSO{sub 4}:Dy) produced by IPEN compared to the TL response of lithium fluoride doped with magnesium and titanium (LiF:Mg,Ti) dosimeters and microdosimeters produced by Harshaw Chemical Company to clinical photon beams dosimetry (6 and 15 MV) using liquid water and PMMA phantoms. - Highlights: Black-Right-Pointing-Pointer Dosimetric study of thermoluminescent detectors of CaSO{sub 4}:Dy, LiF:Mg,Ti and {mu}LiF:Mg,Ti. Black-Right-Pointing-Pointer Clinical (6 and 15 MV) photon beams dosimetry using liquid water and PMMA phantom. Black-Right-Pointing-Pointer Linear behavior to the dose range (0.1 to 5 Gy). Black-Right-Pointing-Pointer TL response reproducibility better than {+-}4.34%. Black-Right-Pointing-Pointer CaSO{sub 4}:Dy represent a cheaper alternative to the TLD-100.

  7. Nanoscale surface modifications to control capillary flow characteristics in PMMA microfluidic devices

    Directory of Open Access Journals (Sweden)

    Mukhopadhyay Subhadeep

    2011-01-01

    Full Text Available Abstract Polymethylmethacrylate (PMMA microfluidic devices have been fabricated using a hot embossing technique to incorporate micro-pillar features on the bottom wall of the device which when combined with either a plasma treatment or the coating of a diamond-like carbon (DLC film presents a range of surface modification profiles. Experimental results presented in detail the surface modifications in the form of distinct changes in the static water contact angle across a range from 44.3 to 81.2 when compared to pristine PMMA surfaces. Additionally, capillary flow of water (dyed to aid visualization through the microfluidic devices was recorded and analyzed to provide comparison data between filling time of a microfluidic chamber and surface modification characteristics, including the effects of surface energy and surface roughness on the microfluidic flow. We have experimentally demonstrated that fluid flow and thus filling time for the microfluidic device was significantly faster for the device with surface modifications that resulted in a lower static contact angle, and also that the incorporation of micro-pillars into a fluidic device increases the filling time when compared to comparative devices.

  8. Stretching DNA in polymer nanochannels fabricated by thermal imprint in PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Thamdrup, Lasse H; Kristensen, Anders [NanoDTU, MIC-Department of Micro and Nanotechnology, Technical University of Denmark, DK-2800 Lyngby (Denmark); Klukowska, Anna [micro resist technology GmbH, D-12555 Berlin (Germany)], E-mail: ak@mic.dtu.dk

    2008-03-26

    We present results regarding the fast and inexpensive fabrication of polymer biochips for investigating the statics and dynamics of DNA confined in nanochannels. The biochips have been fabricated by means of nanoimprint lithography (NIL) in low molecular weight polymethyl methacrylate (PMMA) using a 4 inch diameter two-level hybrid stamp. The fluidic structures were sealed using thermal polymer fusion bonding. The stamp has nanometer- and micrometer-sized protrusions defined in a thermally grown SiO{sub 2} layer and the sol-gel process derived duromeric hybrid polymer Ormocomp, respectively. The stamp is compatible with molecular vapor deposition (MVD), used for applying a durable chlorosilane based antistiction coating, and allows for imprint up to a temperature of 270 deg. C. The extension of YOYO-1 stained T4 GT7 bacteriophage DNA inside the PMMA nanochannels has been experimentally investigated using epi-fluorescence microscopy. The measured average extension length amounts to 20% of the full contour length with a standard deviation of 4%. These results are in good agreement with results obtained by stretching DNA in conventional fused silica nanochannels.

  9. Preparation and Properties of PTFE-PMMA Core-Shell Nanoparticles and Nanocomposites

    Directory of Open Access Journals (Sweden)

    Diego Antonioli

    2012-01-01

    Full Text Available The preparation of polytetrafluoroethylene-poly(methyl methacrylate (PTFE-PMMA core-shell particles was described, featuring controlled size and narrow size distribution over a wide compositional range, through a seeded emulsion polymerization starting from a PTFE seed of 26 nanometers. Over the entire MMA/PTFE range, the particle size increases as the MMA/PTFE ratio increases. A very precise control over the particle size can be exerted by properly adjusting the ratio between the monomer and the PTFE seed. Particles in the 80–240 nm range can be prepared with uniformity indexes suited to build 2D and 3D colloidal crystals. These core-shell particles were employed to prepare nanocomposites with different compositions, through an annealing procedure at a temperature higher than the glass transition temperature of the shell forming polymer. A perfect dispersion of the PTFE particles within the PMMA matrix was obtained and optically transparent nanocomposites were prepared containing a very high PTFE amount.

  10. Electrical percolation, morphological and dispersion properties of MWCNT/PMMA nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, Paulo Henrique da Silva Leite; Marchesin, Marcel Silva; Morales, Ana Rita; Bartoli, Julio Roberto, E-mail: piyke.coelho@gmail.com [Universidade de Campinas (UNICAMP), SP (Brazil). Escola de Engenharia Quimica

    2014-08-15

    Nanocomposites of poly (methyl methacrylate) (PMMA) and carbon nanotubes have a high potential for applications where conductivity and low specific weight are required. This piece of work concerns investigations of the level of dispersion and morphology on the electrical properties of in situ polymerized nanocomposites in different concentrations of multi-walled carbon nanotubes (MWCNT) in a PMMA matrix. The electrical conductivity was measured by the four point probe. The morphology and dispersion was analyzed by Transmission Electron Microscopy (TEM) and Small Angle X-ray Scattering (SAXS). The correlation between electrical conductivity and the MWCNT amount, presented a typical percolation behavior, whose electrical percolation threshold determined by power law relationship was 0.2 vol. (%) The exponent t from the percolation power law indicated the formation of a 3D network of randomly arranged MWCNT. SAXS detected that the structures are intermediate to disks or spheres indicating fractal geometry for the MWCNT aggregates instead of isolated rods. HR-TEM images allowed us to observe the MWCNT individually dispersed into the matrix, revealing their distribution without preferential space orientation and absence of significant damage to the walls. The combined results of SAXS and HR-TEM suggest that MWCNT into the polymeric matrix might present interconnected aggregates and some dispersed single structures. (author)

  11. Surface Roughness Study on Microchannels of CO2 Laser Fabricating Pmma-Based Microfluidic Chip

    Science.gov (United States)

    Chen, Xueye; Li, Tiechuan; Fu, Baoding

    A novel method named soak sacrificial layer ultrasonic method (SSLUM) has been presented for optimizing the surface roughness of the microchannels of polymethyl methacrylate (PMMA)-based microfluidic chips. CO2 laser was used for ablative microchannels on the PMMA sheet, and the effects of key parameters including laser power, laser ablation speed and solution concentration on the surface roughness of microchannels were estimated and optimized by SSLUM. The experimental observation demonstrates that the surface roughness results mainly from the residues on the channel wall, which are produced by the bubbles movement and bursting. The research results show that the surface roughness can be improved effectively by using SSLUM. In our experiment, the best value was Ra = 110nm with laser power 12W, laser ablation speed 10mm/s, the solution concentration 75%, and the time of ultrasonic vibration 25min. SSLUM is proven to be an effective, simple and rapid method for optimizing the surface roughness of microchannels of microfluidic chips.

  12. Bosch-like method for creating high aspect ratio poly(methyl methacrylate) (PMMA) structures

    KAUST Repository

    Haiducu, Marius

    2012-02-02

    This paper presents a method for etching millimetre-deep trenches in commercial grade PMMA using deep-UV at 254 nm. The method is based on consecutive cycles of irradiation and development of the exposed areas, respectively. The exposure segment is performed using an inexpensive, in-house built irradiation box while the development part is accomplished using an isopropyl alcohol (IPA):H2O developer. The method was tested and characterized by etching various dimension square test structures in commercial grade, mirrored acrylic. The undercut of the sidewalls due to the uncollimated nature of the irradiation light was dramatically alleviated by using a honeycomb metallic grid in between the irradiation source and the acrylic substrate and by rotating the latter using a direct current (DC) motor-driven stage. By using an extremely affordable set-up and non-toxic, environmentally friendly materials and substances, this process represents an excellent alternative to microfabricating microfluidic devices in particular and high aspect ratio structures in general using PMMA as substrate. © 2012 SPIE.

  13. Polymethylmethacrylate (PMMA) Material Test Results for the Capillary Flow Experiments (CFE)

    Science.gov (United States)

    Lerch, Bradley A.; Thesken, John C.; Bunnell, Charles T.

    2007-01-01

    In support of the Capillary Flow Experiments (CFE) program, several polymethylmethacrylate (PMMA) flight vessels were constructed. Some vessels used a multipiece design, which was chemically welded together. Due to questions regarding the effects of the experiment fluid (silicone oil) on the weld integrity, a series of tests were conducted to provide evidence of the adequacy of the current vessel design. Tensile tests were conducted on PMMA samples that were both in the as-received condition, and also aged in air or oil for up to 8 weeks. Both welded and unwelded samples were examined. Fracture of the joints was studied using notched tensile specimens and Brazilian disk tests. Results showed that aging had no effect on tensile properties. While the welded samples were weaker than the base parent material, the weld strength was found to be further degraded by bubbles in the weld zone. Finally a fracture analysis using the worst-case fracture conditions of the vessel was performed, and the vessel design was found to have a factor of three safety margin.

  14. Characteristics of charge and discharge of PMMA samples due to electron irradiation

    Institute of Scientific and Technical Information of China (English)

    封国宝; 王芳; 胡天存; 曹猛

    2015-01-01

    In this study, using a comprehensive numerical simulation of charge and discharge processes, we investigate the formation and evolution of negative charge and discharge characteristics of a grounded PMMA film irradiated by a non-focused electron beam. Electron scattering and transport processes in the sample are simulated with the Monte Carlo and the finite-different time-domain (FDTD) methods, respectively. The properties of charge and discharge processes are presented by the evolution of internal currents, charge quantity, surface potential, and discharge time. Internal charge accumulation in the sample may reach saturation by primary electron (PE) irradiation providing the charge duration is enough. Internal free electrons will run off to the ground in the form of leakage current due to charge diffusion and drift during the discharge process after irradiation, while trapped electrons remain. The negative surface potential determined by the charging quantity decreases to its saturation in the charge process, and then increases in the discharge process. A larger thickness of the PMMA film will result in greater charge amount and surface potential in charge saturation and in final discharge state, while the electron mobility of the material has little effects on the final discharge state. Moreover, discharge time is less for smaller thickness or larger electron mobility. The presented results can be helpful for estimating and weakening the charging of insulating samples especially under the intermittent electron beam irradiation in related surface analysis or measurement.

  15. Effect of PMMA impregnation on the fluorescence quantum yield of sol-gel glasses doped with quinine sulfate

    Science.gov (United States)

    Meneses-Nava, M. A.; Barbosa-García, O.; Díaz-Torres, L. A.; Chávez-Cerda, S.; Torres-Cisneros, M.; King, T. A.

    2001-08-01

    The fluorescence quantum yield of quinine sulfate in sol-gel and PMMA impregnated glasses is measured. The observed quantum yield improvement in the sol-gel matrix, compared to ethanol, is interpreted as a reduction of non-radiative relaxation channels by isolation of the molecules by the cage of the glass. PMMA impregnated sol-gel glasses show an extra improvement of the fluorescence yield, which is interpreted as a reduction of the free space and the rigid fixation of the molecules to the matrix.

  16. Experimental ex-vivo validation of PMMA-based bone cements loaded with magnetic nanoparticles enabling hyperthermia of metastatic bone tumors

    Science.gov (United States)

    Harabech, Mariem; Kiselovs, Normunds Rungevics; Maenhoudt, Wim; Crevecoeur, Guillaume; Van Roost, Dirk; Dupré, Luc

    2017-05-01

    Percutaneous vertebroplasty comprises the injection of Polymethylmethacrylate (PMMA) bone cement into vertebrae and can be used for the treatment of compression fractures of vertebrae. Metastatic bone tumors can cause such compression fractures but are not treated when injecting PMMA-based bone cement. Hyperthermia of tumors can on the other hand be attained by placing magnetic nanoparticles (MNPs) in an alternating magnetic field (AMF). Loading the PMMA-based bone cement with MNPs could both serve vertebra stabilization and metastatic bone tumor hyperthermia when subjecting this PMMA-MNP to an AMF. A dedicated pancake coil is designed with a self-inductance of 10 μH in series with a capacitance of 0.1 μF that acts as resonant inductor-capacitor circuit to generate the AMF. The thermal rise is appraised in beef vertebra placed at 10 cm from the AMF generating circuit using optical temperatures sensors, i.e. in the center of the PMMA-MNP bone cement, which is located in the vicinity of metastatic bone tumors in clinical applications; and in the spine, which needs to be safeguarded to high temperature exposures. Results show a temperature rise of about 7 °C in PMMA-MNP whereas the temperature rise in the spine remains limited to 1 °C. Moreover, multicycles heating of PMMA-MNP is experimentally verified, validating the technical feasibility of having PMMA-MNP as basic component for percutaneous vertebroplasty combined with hyperthermia treatment of metastatic bone tumors.

  17. Electron Beam Lithography of HSQ and PMMA Resists and Importance of their Properties to Link the Nano World to the Micro World

    NARCIS (Netherlands)

    Kaleli, B.; Aarnink, Antonius A.I.; Smits, Sander M.; Hueting, Raymond Josephus Engelbart; Wolters, Robertus A.M.; Schmitz, Jurriaan

    2010-01-01

    In this work we investigated the properties of HSQ and PMMA resists focusing on contrast and line width for ebeam lithography (EBL) application. HSQ was found to be a good candidate to have desired line widths but the contrast we obtained was less than it was for PMMA. Since the fluorine based

  18. Study on the mechanical and biological property of PMMA bone cement modified with ultra fine glass fibers and nano-hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    WU Qisheng; CHENG Futao; WEI Wuji

    2007-01-01

    In this study,polymethylmethacrylate(PMMA)bone cement (BC) was modified with ultra-fine glass fibers (UFGF)and nano-hydroxapatite(nano-HAP) synthesized by hydrothermal method.The results show that when the contents of both UFGF and nano-HAP powders are about 5%,the ultimate tensile strength(UTS),ultimate impact toughness (UIT),tensile strain(TS),and elastic modulus(EM)have been promoted a lot.The interface bond was improved by silicane treatment.Pre-grinding mixture of PMMA,UFGF,and nano-HAP can largely improve the mechanical property of PMMA.The PMMA modified with UFGF and HAP has better bioactivity than that modified with pure UFGF when they share the same content.Nano-HAP powder and modified PMMA were characterized by X-ray diffractometry (XRD),scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR).

  19. Investigation of Structural and Electronic Properties of CH3NH3PbI3 Stabilized by Varying Concentrations of Poly(Methyl Methacrylate (PMMA

    Directory of Open Access Journals (Sweden)

    Celline Awino

    2017-08-01

    Full Text Available Studies have shown that perovskites have a high potential of outdoing silicon based solar cells in terms of solar energy conversion, but their rate of degradation is also high. This study reports on improvement on the stability of CH3NH3PbI3 by passivating it with polymethylmethacrylate (PMMA. Structural and electronic properties of CH3NH3PbI3 stabilized by polymethylmethacrylate (PMMA were investigated by varying concentrations of PMMA in the polymer solutions. Stability tests were performed over a period of time using modulated surface photovoltage (SPV spectroscopy, X-ray diffraction (XRD, and photoluminescence (PL measurements. The XRD patterns confirm the tetragonal structure of the deposited CH3NH3PbI3 for every concentration of PMMA. Furthermore, CH3NH3PbI3 coated with 40 mg/mL of PMMA did not show any impurity phase even after storage in air for 43 days. The Tauc gap (ETauc determined on the basis of the in-phase SPV spectra was found in the range from 1.585 to 1.62 eV for the samples stored during initial days, but shifted towards lower energies as the storage time increased. This can be proposed to be due to different chemical reactions between CH3NH3PbI3/PMMA interfaces and air. PL intensity increased with increasing concentration of PMMA except for the perovskite coated with 40 mg/mL of PMMA. PL quenching in the perovskite coated with 40 mg/mL of PMMA can be interpreted as fast electron transfer towards the substrate in the sample. This study shows that, with an optimum concentration of PMMA coating on CH3NH3PbI3, the lifetime and hence stability on electrical and structural behavior of CH3NH3PbI3 is improved.

  20. Exploration on effects of 15 nm SiO2 filler on miscibility, thermal stability and ionic conductivity of PMMA/ENR 50 electrolytes

    Science.gov (United States)

    Zamri, S. F. M.; Latif, F. A.; Ali, A. M. M.; Ibrahim, R.; Azuan, S. I. H. M.; Kamaluddin, N.; Hadip, F.

    2017-02-01

    The effects of silicon dioxide (SiO2) (15 nm) filler on miscibility, thermal stability and ionic conductivity of polymethyl methacrylate/50% epoxidized narural rubber (PMMA/ENR 50) electrolytes were successfully explored. Samples were prepared by solvent casting method with tetrahydrofuran (THF) as solvent and doped with lithium tetrafluoroborate (LiBF4). Fourier transform infrared spectroscopy (FTIR) confirmed the present of hydrogen bond between PMMA and ENR 50. However, the hydrogen bond was reduced when SiO2 was added. Differential scanning calorimeter (DSC) analysis shows that PMMA/ENR 50 blends exhibit two glass transition temperatures (Tgs) recorded at -35 and 89 °C corresponding to the Tg of ENR 50 rich phase (Tg1) and PMMA rich phase (Tg2), respectively. However, the two Tgs almost merging and reduced when SiO2 was added. Tg1 was found increases as SiO2 weight percent increased. Thermogravimetric analysis (TGA) revealed that thermal degradation temperatures (Tds) of SiO2 filled PMMA/ENR 50 was similar as PMMA/ENR 50. Interestingly, thermal degradation temperatures of the loss of impurities (Td1) and thermal degradation temperatures of PMMA side chain (Td2) were increased when SiO2 was added. Meanwhile thermal degradation temperatures of main PMMA and ENR 50 main chain (Td3) was decreased as SiO2 was added. There was no significant change in Td1, Td2 and Td3 as SiO2 weight percent was varied. Electrochemical impedence spectroscopy (EIS) analysis shows that room temperature ionic conductivity of SiO2 filled PMMA/ENR 50 electrolytes were higher compaed PMMA/ENR 50 electrolyte with two conductivity maxima.

  1. Study on the denture base plate of nanometer(PMMA/SiO2)composite material%纳米(PMMA/SiO2)义齿基托复合材料的基础研究

    Institute of Scientific and Technical Information of China (English)

    俞胜; 徐连来; 李长福; 李鸿琦; 支敏

    2003-01-01

    目的:研究纳米SiO2颗粒对聚甲基丙烯酸甲酯(PMMA)基托的增强增韧改变.方法:利用原位聚合的方法将纳米SiO2颗粒加入甲基丙烯酸甲酯(MMA)单体中制成不同浓度的(PMMA/SiO2)纳米义齿基托复合材料.对各组基托材料的抗弯强度、拉伸强度等指标进行分类比较,并对结果进行统计分析.结朵:添加纳米SiO2颗粒浓度为0.25g‰ml的(PMMA/SiO2)义齿基托复合材料与普通PMMA义齿基托材料之间比较,其抗弯强度和拉伸强度提高无显著性差异(P>0.05).而添加纳米SiO2颗粒浓度为0.50 g‰ml、0.75g‰ml、1.00g‰ml、的PMMA/SiO2义齿基托复合材料与普通PMMA义齿基托材料相比,其抗弯强度和拉伸强度均有所提高(P<0.05).结论:在聚甲基丙烯酸甲酯(PMMA)基托中加入一定浓度的纳米SiO2颗粒可以提高传统义齿基托的抗弯强度和拉伸强度.

  2. [The porosity, microhardness, roughness and internal stresses of PMMA base materials in relation to their isolation. 1. Porosity and microhardness].

    Science.gov (United States)

    Lockowandt, P; Loges, H; Wagner, I V

    1989-01-01

    Selected material properties of hot and cold polymerized denture basic materials (polymethylmethacrylate) were investigated after different methods of isolation: alginate, tin foil and silicone. Both tin foil and silicone isolation the handling of which is much easier result in a decreased portion of porosities and an increased microhardness in the PMMA.

  3. Influence of blue and red light illumination on the holographic storage in an azopolyester–PMMA blend

    DEFF Research Database (Denmark)

    Berges, C.; Díez, I.; Javakhishvili, Irakli

    2014-01-01

    Volume holographic polarization gratings have been stored in thick films of blends of a side-chain azobenzene polyester and a poly(methyl methacrylate) (PMMA) homopolymers. The azobenzene content in the blend is 0.2wt%, and the holograms are recorded by using 2ms 4mJ/cm2 488nm light pulses. The d...

  4. Photoresponsive Azopolyester–PMMA Block Copolymers Obtained by Combination of ATRP, Polycondensation, and “Click” Chemistry

    DEFF Research Database (Denmark)

    Berges, Cristina; Javakhishvili, Irakli; Hvilsted, Søren

    2012-01-01

    Novel azobenzene‐containing block copolymers (BCs) with a polyester block bearing azobenzene moieties in the side chain and a poly (methyl methacrylate) (PMMA) block have been synthesized by the combination of atom transfer radical polymerization (ATRP), polycondensation, and “click” chemistry. T...

  5. Charging of poly(methyl methacrylate) (PMMA) colloids in cyclohexyl bromide: locking, size dependence, and particle mixtures.

    Science.gov (United States)

    van der Linden, Marjolein N; Stiefelhagen, Johan C P; Heessels-Gürboğa, Gülşen; van der Hoeven, Jessi E S; Elbers, Nina A; Dijkstra, Marjolein; van Blaaderen, Alfons

    2015-01-13

    We studied suspensions of sterically stabilized poly(methyl methacrylate) (PMMA) particles in the solvent cyclohexyl bromide (CHB; εr = 7.92). We performed microelectrophoresis measurements on suspensions containing a single particle species and on binary mixtures, using confocal microscopy to measure the velocity profiles of the particles. We measured the charge of so-called locked PMMA particles, for which the steric stabilizer, a comb-graft stabilizer of poly(12-hydroxystearic acid) (PHSA) grafted on a backbone of PMMA, was covalently bonded to the particle, and for unlocked particles, for which the stabilizer was adsorbed to the surface of the particle. We observed that locked particles had a significantly higher charge than unlocked particles. We found that the charge increase upon locking was due to chemical coupling of 2-(dimethylamino)ethanol to the PMMA particles, which was used as a catalyst for the locking reaction. For particles of different size we obtained the surface potential and charge from the electrophoretic mobility of the particles. For locked particles we found that the relatively high surface potential (∼ +5.1 kBT/e or +130 mV) was roughly constant for all particle diameters we investigated (1.2 μm particle charge was proportional to the square of the diameter.

  6. Charging of Poly(methyl methacrylate) (PMMA) Colloids in Cyclohexyl Bromide : Locking, Size Dependence, and Particle Mixtures

    NARCIS (Netherlands)

    van der Linden, Marjolein N.; Stiefelhagen, Johan C. P.; Heessels-Gurboga, Gulsen; der Hoeven, Jessi E. S. van; Elbers, Nina A.; Dijkstra, Marjolein; van Blaaderen, Alfons

    2015-01-01

    We studied suspensions of sterically stabilized poly(methyl methacrylate) (PMMA) particles in the solvent cyclohexyl bromide (CHB; epsilon(r) = 7.92). We performed microelectrophoresis measurements on suspensions containing a single particle species and on binary mixtures, using confocal microscopy

  7. The short-term effects of PMMA and RGP contact lens wear on keratometric behaviour: a pilot study*

    Directory of Open Access Journals (Sweden)

    E. Chetty

    2010-12-01

    Full Text Available This article represents the preliminary findings of a larger study that included 24 subjects that were equally divided into three groups, namely, the PMMA (polymethyl methacrylate group, the RGP(rigid gas permeable group and the control group. The aim of this study was to establish the short term effects (if any of PMMA and RGP contact lens wear on keratometric behaviour. A controlsubject was also included in the study to establish a reference fornormal diurnal changes in keratometric behaviour. Fifty successive auto-keratometric measurements were taken before and immediately after three hours of rigid contact lens wear for the first subject in the PMMA group and the first subject in the RGP group (experimental samples. Fifty successive auto-keratometric measurements were also taken on the first subject of the control group before and immediately after three hours of no lens wear (control sample. Data collected were analysed using multivariate statistical methods that in the past have been used infrequently in this area of study. This investigation revealed that, at least in these two randomly selected subjects, rigid contact lens wear appears to  influence keratometric behaviour (PMMA contact lenses more so than RGP contact lenses. (S Afr Optom 2010 69(4 173-181

  8. Random lasing and reversible photodegradation in disperse orange 11 dye-doped PMMA with dispersed ZrO2 nanoparticles

    Science.gov (United States)

    Anderson, Benjamin R.; Gunawidjaja, Ray; Eilers, Hergen

    2016-01-01

    We report the observation of intensity feedback random lasing at 645 nm in disperse orange 11 dye-doped PMMA (DO11/PMMA) with dispersed ZrO2 nanoparticles (NPs). The lasing threshold is found to increase with concentration, with the lasing threshold for 0.1 wt% being 75.8 ± 9.4 MW cm-2 and the lasing threshold for 0.5 wt% being 121.1 ± 2.1 MW cm-2, with the linewidth for both concentrations found to be ≈10 nm. We also consider the material’s photostability and find that it displays fully reversible photodegradation with the photostability and recovery rate being greater than previously observed for DO11/PMMA without NPs. This enhancement in photostability and recovery rate is found to be explicable by the modified correlated chromophore domain model, with the NPs resulting in the domain free energy advantage increasing from 0.29 eV to 0.41 eV. Additionally, the molecular decay and recovery rates are found to be in agreement with previous measurements of DO11/PMMA (Ramini et al 2013 Polym. Chem. 4 4938). These results present new avenues for the development of robust photodegradation-resistant organic dye-based optical devices.

  9. A Mössbauer study of the chemical stability of iron oxide nanoparticles in PMMA and PVB beads

    DEFF Research Database (Denmark)

    Chen, Wei; Mørup, Steen; Hansen, Mikkel Fougt;

    2008-01-01

    We have prepared magnetic beads consisting of iron oxide nanoparticles in a polymethyl methacrylate (PMMA) and a polyvinyl butyral (PVB) matrix. High-field Mossbauer studies show that the particles have an almost perfect collinear spin structure and magnetization measurements show that they are s...

  10. Random Lasing and Reversible Photodegradation in Disperse Orange 11 Dye-Doped PMMA with Dispersed ZrO$_2$ Nanoparticles

    CERN Document Server

    Anderson, Benjamin R; Eilers, Hergen

    2016-01-01

    We report the observation of intensity feedback random lasing at 645 nm in Disperse Orange 11 dye-doped PMMA (DO11/PMMA) with dispersed ZrO$_2$ nanoparticles (NPs). The lasing threshold is found to increase with concentration, with the lasing threshold for 0.1 wt\\% being $75.8 \\pm 9.4$ MW/cm$^2$ and the lasing threshold for 0.5 wt\\% being $121.1 \\pm 2.1$ MW/cm$^2$, with the linewidth for both concentrations found to be $\\approx 10$ nm. We also consider the material's photostability and find that it displays fully reversible photodegradation with the photostability and recovery rate being greater than previously observed for DO11/PMMA without NPs. This enhancement in photostability and recovery rate is found to be explicable by the modified correlated chromophore domain model, with the NPs resulting in the domain free energy advantage increasing from 0.29 eV to 0.41 eV. Additionally, the molecular decay and recovery rates are found to be in agreement with previous measurements of DO11/PMMA [Polymer Chemistry \\...

  11. Different influence of Ti, PMMA, UHMWPE, and Co-Cr particles on peripheral blood monocytes during periprosthetic inflammation.

    Science.gov (United States)

    Zhang, Kai; Yang, Shang-You; Yang, Shuye; Bai, Ling; Li, Peng; Liu, Dong; Schurman, John R; Wooley, Paul H

    2015-01-01

    This study investigated cellular trafficking and inflammatory markers in orthopedic biomaterial particle-challenged human peripheral blood monocytes (PBMCs) using a murine immunodeficiency (SCID) model. Periprosthetic tissues from aseptic loosening patients were transplanted into muscles of SCID mice. PBMCs from the same patients were stimulated in vitro with Ti-6Al-4V, PMMA, UHMWPE, or Co-Cr particles for 3 days before administered intraperitoneally to the periprosthetic tissue-implanted mice. The xenografts were harvested 2 weeks later for histological and molecular analyses. Significant cell infiltration was obvious in the transplanted tissues from mice transfused with Ti-alloy, PMMA and UHMWPE-provoked PBMCs compared to controls, and UHMWPE-provoked PBMCs group accumulated significantly more cells among all groups. There were ubiquitous TRAP+ stained cells in all xenografts from particle-stimulated PBMCs mice. Immunohistochemical staining indicated that significantly more IL-1β and TNF positive cells occurred in Ti and PMMA groups; while the UHMWPE group resulted in stronger positive MCP-1 and IL-6 stains. Polymerase chain reaction (PCR) confirmed overexpression of both IL-1β and TNF in Ti and PMMA-stimulated groups; and more MIP-1α gene expression developed in the UHMWPE group. Overall, different type of orthopedic materials influenced the trafficking ability of particle-activated PBMCs which may depend on upregulation of various proinflammatory cytokines and chemokines.

  12. Assessing the Local Nanomechanical Properties of Self-Assembled Block Copolymer Thin Films by Peak Force Tapping.

    Science.gov (United States)

    Lorenzoni, Matteo; Evangelio, Laura; Verhaeghe, Sophie; Nicolet, Célia; Navarro, Christophe; Pérez-Murano, Francesc

    2015-10-27

    The mechanical properties of several types of block copolymer (BCP) thin films have been investigated using PeakForce quantitative nanomechanical mapping. The samples consisted of polystyrene/poly(methylmethacrylate) (PS/PMMA)-based BCP thin films with different pitches both randomly oriented and self-assembled. The measured films have a critical thickness below 50 nm and present features to be resolved of less than 22 nm. Beyond measuring and discriminate surface elastic modulus and adhesion forces of the different phases, we tuned the peak force parameters in order to reliably image those samples, avoiding plastic deformation. The method is able to detect the changes in mechanical response associated with the orientation of the PMMA cylinders with respect to the substrate (parallel versus vertical). The nanomechanical investigation is also capable of recognizing local stiffening due to the preferential growth of alumina deposited by atomic layer deposition on BCP samples, opening up new possibilities in the field of hard mask materials characterization.

  13. Electric Field Effects on Photoluminescence of CdSe Nanoparticles in a PMMA Film

    Directory of Open Access Journals (Sweden)

    Takakazu Nakabayashi

    2014-06-01

    Full Text Available External electric field effects on spectra and decay of photoluminescence (PL as well as on absorption spectra were measured for CdSe nanoparticles in a poly(methyl methacrylate (PMMA film. Electrophotoluminescence (E-PL spectra as well as electroabsorption spectra show a remarkable Stark shift which depends on the particle size, indicating a large electric dipole moment in the first exciton state. The E-PL spectra also show that PL of CdSe is quenched by application of electric fields, and the magnitude of the field-induced quenching becomes larger with increasing size. The PL decay profiles observed in the absence and presence of electric field show that the field-induced quenching of PL mainly originates from the field-induced decrease in population of the emitting state prepared through the relaxation from the photoexcited state.

  14. 3D optical phase reconstruction within PMMA samples using a spectral OCT system

    Science.gov (United States)

    Briones-R., Manuel d. J.; De La Torre-Ibarra, Manuel H.; Mendoza Santoyo, Fernando

    2015-08-01

    The optical coherence tomography (OCT) technique has proved to be a useful method in biomedical areas such as ophthalmology, dentistry, dermatology, among many others. In all these applications the main target is to reconstruct the internal structure of the samples from which the physician's expertise may recognize and diagnose the existence of a disease. Nowadays OCT has been applied one step further and is used to study the mechanics of some particular type of materials, where the resulting information involves more than just their internal structure and the measurement of parameters such as displacements, stress and strain. Here we report on a spectral OCT system used to image the internal 3D microstructure and displacement maps from a PMMA (Poly-methyl-methacrylate) sample, subjected to a deformation by a controlled three point bending and tilting. The internal mechanical response of the polymer is shown as consecutive 2D images.

  15. A PMMA Passive Micromixer with Three-Dimensional Tortuous Mixing Chamber

    Institute of Scientific and Technical Information of China (English)

    He Zhang; XiaoWei Liu; JiaLu Tang; XiaoWei Han; Li Tian

    2014-01-01

    In this paper, we design and fabricate a novel three⁃dimensional passive⁃micro⁃mixer by using Polymethyl methacrylate (PMMA). The mixer is fabricated by using ultra⁃precision engraving machine and bonded by an organic solvent fumigation bonding method. The mixer combines two fluid streams into a mixing chamber integrated with T⁃shaped pre⁃mixing and six tortuous shaped mixing elements. We have employed three⁃dimensional numerical simulations to evaluate the mixing efficiency. The simulation results indicate, under inlet fluid pressure p = 10 ( Pa ) , compared to the planar serpentine mixer and tortuous mixer, the concentration fluctuation range at the outlet diagonal reduce to 48% and 71�6% respectively. And the mixing concentration variances also show that the mixing efficiency has a significant increase. We characterize the device by using visualization microscope, and the results are consistent with the simulation data. The device demonstrates the promising capabilities for micro total analysis system integration.

  16. Finite element thermal analysis for PMMA/st.st.304 laser direct joining

    Science.gov (United States)

    Hussein, Furat I.; Salloomi, Kareem N.; Akman, E.; Hajim, K. I.; Demir, A.

    2017-01-01

    This work is concerned with building a three-dimensional (3D) ab-initio models that is capable of predicting the thermal distribution of laser direct joining processes between Polymethylmethacrylate (PMMA) and stainless steel 304(st.st.304). ANSYS® simulation based on finite element analysis (FEA) was implemented for materials joining in two modes; laser transmission joining (LTJ) and conduction joining (CJ). ANSYS® simulator was used to explore the thermal environment of the joints during joining (heating time) and after joining (cooling time). For both modes, the investigation is carried out when the laser spot is at the middle of the joint width, at 15 mm from the commencement point (joint edge) at traveling time of 3.75 s. Process parameters involving peak power (Pp=3 kW), pulse duration (τ=5 ms), pulse repetition rate (PRR=20 Hz) and scanning speed (v=4 mm/s) are applied for both modes.

  17. A Moessbauer study of the chemical stability of iron oxide nanoparticles in PMMA and PVB beads

    Energy Technology Data Exchange (ETDEWEB)

    Chen Wei [Department of Physics, Technical University of Denmark, Building 307, DK-2800 Kongens Lyngby (Denmark); College of Physics Science and Information Engineering, Hebei Normal University, Shijiazhuang 050016 (China); Morup, Steen [Department of Physics, Technical University of Denmark, Building 307, DK-2800 Kongens Lyngby (Denmark); Hansen, Mikkel F. [Department of Micro and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark)], E-mail: mfh@mic.dtu.dk; Banert, Tobias; Peuker, Urs A. [Institute of Chemical Engineering, Clausthal University of Technology, D-38678 Clausthal-Zellerfeld (Germany)

    2008-08-15

    We have prepared magnetic beads consisting of iron oxide nanoparticles in a polymethyl methacrylate (PMMA) and a polyvinyl butyral (PVB) matrix. High-field Moessbauer studies show that the particles have an almost perfect collinear spin structure and magnetization measurements show that they are superparamagnetic at room temperature at a time scale of seconds. We have followed the oxidation of the particles, which initially have a stoichiometry close to magnetite. The oxidation is fast during the first 2-3 weeks and then continues slowly such that even after 30 weeks the particles have not completely transformed to maghemite. The PVB beads are hydrophilic and biocompatible and are therefore well suited for applications in medicine and biology.

  18. Imaging Studies of photodamage and self-healing in disperse orange 11 dye-doped PMMA

    CERN Document Server

    Anderson, Benjamin; Kuzyk, Mark G

    2011-01-01

    We report on optical imaging studies of self-healing after laser-induced photodamage in disperse orange 11 dye doped into poly(methyl methacrylate) (PMMA) polymer. In particular, the high spatial-contrast image of the damage track made by a line focus pump laser allows the recovery rates to be measured as a function of burn dose using the relationship between transverse distance and pump intensity profile. The time evolution of the damaged population results in an intensity-independent time constant of {\\tau} = 490\\pm23 min, in agreement with independent measurements of the time evolution of amplified spontaneous emission. Also observed is a damage threshold above which the material does not fully recover.

  19. Nuclear reaction measurements of 95 MeV/u 12C interactions on PMMA for hadrontherapy

    Science.gov (United States)

    Braunn, B.; Labalme, M.; Ban, G.; Chevallier, M.; Colin, J.; Cussol, D.; Dauvergne, D.; Fontbonne, J. M.; Haas, F.; Guertin, A.; Lebhertz, D.; Le Foulher, F.; Pautard, C.; Ray, C.; Rousseau, M.; Salsac, M. D.; Stuttge, L.; Testa, E.; Testa, M.

    2011-11-01

    The ion dose deposition in tissues is characterized by a favorable depth dose profile (i.e. Bragg peak) and a small lateral spread. In order to keep these benefits of ions in cancer treatments, a very high accuracy is required on the dose deposition (±3%). For given target stoichiometry and geometry, the largest uncertainty on the physical dose deposition is due to the ion nuclear fragmentation. We have performed an experiment at GANIL with a 95 MeV/u 12C beam on thick tissue equivalent PMMA targets (thicknesses: 5, 10, 15, 20 and 25 mm). The main goals of this experiment are to provide experimental fragmentation data for benchmarking the physical models used for treatment planning. Production rates, energy and angular distributions of charged fragments have been measured. The purpose of this paper is to present the results of this experiment.

  20. Zeonex-PMMA microstructured polymer optical FBGs for simultaneous humidity and temperature sensing.

    Science.gov (United States)

    Woyessa, Getinet; Pedersen, Jens K M; Fasano, Andrea; Nielsen, Kristian; Markos, Christos; Rasmussen, Henrik K; Bang, Ole

    2017-03-15

    In this Letter, we report for the first time, to the best of our knowledge, the fabrication and characterization of a Zeonex/PMMA microstructured polymer optical fiber (mPOF) Bragg grating sensor for simultaneous monitoring of relative humidity (RH) and temperature. The sensing element (probe) is based on two separate in-line fiber Bragg gratings (FBGs) inscribed in the fabricated mPOF. A root mean square deviation of 0.8% RH and 0.6°C in the range of 10%-90% RH and 20°C-80°C was found. The developed mPOFBG sensor constitutes an efficient route toward low-cost, easy-to-fabricate and compact multi-parameter sensing solutions.

  1. Long-time scale spectral diffusion in PMMA: Beyond the TLS model?

    Science.gov (United States)

    Müller, J.; Haarer, D.; Khodykin, O. V.; Kharlamov, B. M.

    1999-05-01

    Spectral diffusion (SD) in PMMA doped with H 2-TPP is investigated at 4.2 K on a time scale of 3 ÷ 10 6 s via optical hole burning. Two contradictory (in frames of the TLS model) results are obtained. The first is the absence of aging effects which put the upper limit for the TLS relaxation times to tens of minutes. The second is an intensive superlogarithmic SD on the whole time scale of the experiment, which evidences the presence of very slow relaxations, independent of the sample history on the time scale of up to 2 months. The presented results provide the clear evidence of the deviation of SD behavior from the TLS model predictions at moderately low temperatures. The concept of structural relaxations is applied for a qualitative interpretation of the experimental data.

  2. Ultra lightweight PMMA-based composite plates with robust super-hydrophobic surfaces.

    Science.gov (United States)

    Pareo, Paola; De Gregorio, Gian Luca; Manca, Michele; Pianesi, Maria Savina; De Marco, Luisa; Cavallaro, Francesco; Mari, Margherita; Pappadà, Silvio; Ciccarella, Giuseppe; Gigli, Giuseppe

    2011-11-15

    Extremely lightweight plates made of an engineered PMMA-based composite material loaded with hollow glass micro-sized spheres, nano-sized silica particles and aluminum hydroxide prismatic micro-flakes were realized by cast molding. Their interesting bulk mechanical properties were combined to properly tailored surface topography compatible with the achievement of a superhydrophobic behavior after the deposition of a specifically designed hydrophobic coating. With this aim, we synthesized two different species of fluoromethacrylic polymers functionalized with methoxysilane anchoring groups to be covalently grafted onto the surface protruding inorganic fillers. By modulating the feed composition of the reacting monomers, it was possible to combine the hydrophobic character of the polymer with an high adhesion strength to the substrate and hence to maximize both the water contact angle (up to 157°) and the durability of the easy-to-clean effect (up to 2000 h long outdoor exposure).

  3. PMMA-based resists for a spectral range near 13 nm

    CERN Document Server

    Bulgakova, S A; Luchin, V I; Mazanova, L M; Molodnjakov, S A; Salashchenko, N N

    2000-01-01

    A number of poly(meth)acrylates positive resists of various chemical structures were synthesized and the sensitivity of 0.2 mu m resists films to soft X-ray radiation of a laser plasma source at a wavelength of 13 nm was investigated. We found that the sensitivity of methylmethacrylate (MMA) copolymers depending on the nature of comonomers changes within the limits of 12.3-1.7 mJ/cm sup 2 in a combination with the contrast gamma=5.4-1.0. This sensitivity is higher than that of PMMA, which changes from 12 to 45 mJ/cm sup 2 at the contrast gamma=2.6-8.0 depending on the developer composition of methylethylketone (MEK)/isopropyl alcohol (IPA).

  4. Control of PDMS crosslinking by encapsulating a hydride crosslinker in a PMMA microcapsule

    DEFF Research Database (Denmark)

    Ma, Baoguang; Hansen, Jens Henrik; Hvilsted, Søren;

    2014-01-01

    crosslinker in a PMMA shell. Microcapsules are mixed with vinyl-terminated PDMS to create a gelation system, which allows for storage at 50 °C, without premature gelation, and in addition allows for extensive crosslinking reaction at 120 °C. Both visual observations and rheological studies show that a robust...... PDMS elastomer is obtained upon heating the gelation system. Furthermore, the influence of stoichiometric imbalance on the equilibrium storage modulus of the PDMS network is investigated, by employing different amounts of microcapsules in vinyl-terminated PDMS. It has been found that adding...... microcapsules increases the equilibrium storage modulus of the PDMS elastomer until the diffusion of the hydride crosslinker is constricted. An optimum amount of crosslinker used in the control crosslinking reaction has also been found. However, compared to the pure PDMS elastomer, the modulus of the PDMS...

  5. Colour shift and mechanism investigation on the PMMA diffuser used in LED-based luminaires

    Science.gov (United States)

    Lu, Guangjun; van Driel, W. D.; Fan, Xuejun; Yazdan Mehr, M.; Fan, Jiajie; Qian, Cheng; Jansen, K. M. B.; Zhang, G. Q.

    2016-04-01

    PMMA material is widely used in LED-based luminaires due to several advantages such as excellent optical transparency, durability against radiation, surface hardness (scratch free), rigidity and strength and can be completely recycled. However, few studies have been reported on the colour shift and failure mechanisms caused by this type of material. This paper experimentally investigated PMMA materials with different aging conditions. The following conclusions could be drawn. (1) Discolouration was not observed for any sample subjected to aging of 85 °C for 5000 h, or with additional blue light irradiation for 5000 h, or with additional humidity of 85%RH for 5000 h, or even with aging of 100 °C for 3000 h. (2) The specimen subjected to aging of 150 °C for 360 h has a surface discoloration and has a significant wavelength dependent degradation in the transmission spectrum caused by oxidation. The specimen with aging of 100 °C for 3000 h has a less oxidation, although no significant transmission spectrum reduction was observed. (3) Using such aged specimen as a diffuser mounted on a LED-based luminaire, the radiant flux peak intensity in the blue light area has a more severe reduction than that in the yellow light area, which results in a reduction of the radiant flux intensity ratio of blue light to yellow light and hence induces the colour shift to yellow. The colour shift investigated is 0.005, very close to the general failure criterion of 0.007, while the lumen decay is 10.2%, far less than the failure criterion of 30%.

  6. Degradation mechanism of AlInGaP light emitting diodes during PMMA encapsulation and operation

    Energy Technology Data Exchange (ETDEWEB)

    Preuss, S.

    2007-11-15

    In this thesis we investigate the degradation mechanism of AlInGaP light emitting diodes (LEDs) during encapsulation and operation. The AlInGaP LEDs are encapsulated using an injection moulding tool. The molded part acts as physical housing as well as tailors the radiation pattern. Thus a narrow light beam with a spread angle of {alpha}=10 has been observed. The LED temperature has been measured by the voltage variation of the LED which is caused by the temperature change at a constant current. Thus the thermal load of the LED chips during the encapsulation process is investigated. To verify the temperature measurement a simulation based on the finite element method has been carried out. The experimental and theoretical data are in good agreement. The LED properties are investigated before and after the encapsulation. The results are compared and we found a reduction of the serial resistance and an enhanced luminous efficiency. The peak emission energy remained constant, but a peak broadening of {delta}E=9meV has been observed. A slight polarisation of the emitted light is an indication for a polarization effect of the polymethylmethacrylat (PMMA) housing. Accelerated degradation experiments using high forward currents are performed to estimate the lifetime of the PMMA encapsulated LEDs. A diffusion model is presented to explain the decay in luminous flux versus degradation time and degradation current. We believe that the reduction of quantum efficiency is caused by p-type dopant diffusion into the active layer where it acts as a non-radiative recombination centre. Using this model we determine the lifetime under the recommended drive current of I=20mA. The resulting lifetime is t=1.5.10{sup 6}h using a reduction of 50% in the luminous flux as failure criteria. (orig.)

  7. Effect of Process Parameter in Laser Cutting of PMMA Sheet and ANFIS Modelling for Online Control

    Directory of Open Access Journals (Sweden)

    Hossain Anamul

    2016-01-01

    Full Text Available Laser beam machining (LBM is a promising and high accuracy machining technology in advanced manufacturing process. In LBM, crucial machining qualities of the end product include heat affected zone, surface roughness, kerf width, thermal stress, taper angle etc. It is essential for industrial applications especially in laser cutting of thermoplastics to acquire output product with minimum kerf width. The kerf width is dependent on laser input parameters such as laser power, cutting speed, standoff distance, assist gas pressure etc. However it is difficult to get a functional relationship due to the high uncertainty among these parameters. Hence, total 81 sets of full factorial experiment were conducted, representing four input parameters with three different levels. The experiments were performed by a continuous wave (CW CO2 laser with the mode structure of TEM01 named Zech laser machine that can provide maximum laser power up to 500 W. The polymethylmethacrylate (PMMA sheet with thickness of 3.0 mm was used for this experiment. Laser power, cutting speed, standoff distance and assist gas pressure were used as input parameters for the output named kerf width. Standoff distance, laser power, cutting speed and assist gas pressure have the dominant effect on kerf width, respectively, although assist gas has some significant effect to remove the harmful gas. ANFIS model has been developed for online control purposes. This research is considered important and helpful for manufacturing engineers in adjusting and decision making of the process parameters in laser manufacturing industry of PMMA thermoplastics with desired minimum kerf width as well as intricate shape design purposes.

  8. Degradation mechanism of AlInGaP light emitting diodes during PMMA encapsulation and operation

    Energy Technology Data Exchange (ETDEWEB)

    Preuss, S.

    2007-11-15

    In this thesis we investigate the degradation mechanism of AlInGaP light emitting diodes (LEDs) during encapsulation and operation. The AlInGaP LEDs are encapsulated using an injection moulding tool. The molded part acts as physical housing as well as tailors the radiation pattern. Thus a narrow light beam with a spread angle of {alpha}=10 has been observed. The LED temperature has been measured by the voltage variation of the LED which is caused by the temperature change at a constant current. Thus the thermal load of the LED chips during the encapsulation process is investigated. To verify the temperature measurement a simulation based on the finite element method has been carried out. The experimental and theoretical data are in good agreement. The LED properties are investigated before and after the encapsulation. The results are compared and we found a reduction of the serial resistance and an enhanced luminous efficiency. The peak emission energy remained constant, but a peak broadening of {delta}E=9meV has been observed. A slight polarisation of the emitted light is an indication for a polarization effect of the polymethylmethacrylat (PMMA) housing. Accelerated degradation experiments using high forward currents are performed to estimate the lifetime of the PMMA encapsulated LEDs. A diffusion model is presented to explain the decay in luminous flux versus degradation time and degradation current. We believe that the reduction of quantum efficiency is caused by p-type dopant diffusion into the active layer where it acts as a non-radiative recombination centre. Using this model we determine the lifetime under the recommended drive current of I=20mA. The resulting lifetime is t=1.5.10{sup 6}h using a reduction of 50% in the luminous flux as failure criteria. (orig.)

  9. Influence of 400 keV carbon ion implantation on structural, optical and electrical properties of PMMA

    Energy Technology Data Exchange (ETDEWEB)

    Arif, Shafaq, E-mail: sarif2005@gmail.com [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Rafique, M. Shahid [Department of Physics, University of Engineering & Technology, Lahore 54000 (Pakistan); Saleemi, Farhat; Sagheer, Riffat [Department of Physics, Lahore College for Women University, Lahore 54000 (Pakistan); Naab, Fabian; Toader, Ovidiu [Department of Nuclear Engineering and Radiological Sciences, Michigan Ion Beam Laboratory, University of Michigan, MI 48109-2104 (United States); Mahmood, Arshad; Rashid, Rashad [National Institute of Lasers and Optronics (NILOP), P.O. Nilore, Islamabad (Pakistan); Mahmood, Mazhar [Department of Metallurgy & Materials Engineering, Pakistan Institute of Engineering & Applied Sciences (PIEAS), Islamabad (Pakistan)

    2015-09-01

    Ion implantation is a useful technique to modify surface properties of polymers without altering their bulk properties. The objective of this work is to explore the 400 keV C{sup +} ion implantation effects on PMMA at different fluences ranging from 5 × 10{sup 13} to 5 × 10{sup 15} ions/cm{sup 2}. The surface topographical examination of irradiated samples has been performed using Atomic Force Microscope (AFM). The structural and chemical modifications in implanted PMMA are examined by Raman and Fourier Infrared Spectroscopy (FTIR) respectively. The effects of carbon ion implantation on optical properties of PMMA are investigated by UV–Visible spectroscopy. The modifications in electrical conductivity have been measured using a four point probe technique. AFM images reveal a decrease in surface roughness of PMMA with an increase in ion fluence from 5 × 10{sup 14} to 5 × 10{sup 15} ions/cm{sup 2}. The existence of amorphization and sp{sup 2}-carbon clusterization has been confirmed by Raman and FTIR spectroscopic analysis. The UV–Visible data shows a prominent red shift in absorption edge as a function of ion fluence. This shift displays a continuous reduction in optical band gap (from 3.13 to 0.66 eV) due to formation of carbon clusters. Moreover, size of carbon clusters and photoconductivity are found to increase with increasing ion fluence. The ion-induced carbonaceous clusters are believed to be responsible for an increase in electrical conductivity of PMMA from (2.14 ± 0.06) × 10{sup −10} (Ω-cm){sup −1} (pristine) to (0.32 ± 0.01) × 10{sup −5} (Ω-cm){sup −1} (irradiated sample)

  10. Cardiovascular changes after PMMA vertebroplasty in sheep: the effect of bone marrow removal using pulsed jet-lavage.

    Science.gov (United States)

    Benneker, Lorin M; Krebs, Jörg; Boner, Vanessa; Boger, Andreas; Hoerstrup, Simon; Heini, Paul F; Gisep, Armando

    2010-11-01

    Clinically, the displacement of intravertebral fat into the circulation during vertebroplasty is reported to lead to problems in elderly patients and can represent a serious complication, especially when multiple levels have to be treated. An in vitro study has shown the feasibility of removing intravertebral fat by pulsed jet-lavage prior to vertebroplasty, potentially reducing the embolization of bone marrow fat from the vertebral bodies and alleviating the cardiovascular changes elicited by pulmonary fat embolism. In this in vivo study, percutaneous vertebroplasty using polymethylmethacrylate (PMMA) was performed in three lumbar vertebrae of 11 sheep. In six sheep (lavage group), pulsed jet-lavage was performed prior to injection of PMMA compared to the control group of five sheep receiving only PMMA vertebroplasty. Invasive recording of blood pressures was performed continuously until 60 min after the last injection. Cardiac output and arterial blood gas parameters were measured at selected time points. Post mortem, the injected cement volume was measured using CT and lung biopsies were processed for assessment of intravascular fat. Pulsed jet-lavage was feasible in the in vivo setting. In the control group, the injection of PMMA resulted in pulmonary fat embolism and a sudden and significant increase in mean pulmonary arterial pressure. Pulsed jet-lavage prevented any cardiovascular changes and significantly reduced the severity of bone marrow fat embolization. Even though significantly more cement had been injected into the lavaged vertebral bodies, significantly fewer intravascular fat emboli were identified in the lung tissue. Pulsed jet-lavage prevented the cardiovascular complications after PMMA vertebroplasty in sheep and alleviated the severity of pulmonary fat embolism.

  11. Assessment of the Resistance of a Polymethylmethacrylate (Pmma Dynamic Compression Plate (DCP Prototype Tested on Osteotomized Canine Femurs

    Directory of Open Access Journals (Sweden)

    Leonel Cardona R.

    2011-06-01

    Full Text Available Femur fractures are the most frequent long bone fractures in small animals. Due to the femur’s anatomical position, it is difficult to immobilize, and therefore internal fixations are very useful. Dynamic compression plates (DCP provide high stability, are durable, minimize fragment movement and promote primary healing of the bone. Advantages of this treatment include anatomical reconstruction, early mobility and carrying capacity of the affected limb. Polymethylmethacrylate (PMMA is an acrylic resin that has proved very useful in bone tumor treatment, cranial deformation prosthesis, percutaneous vertebroplasty and testicular prosthesis in animals. The purpose of this study was to manufacture DCP-PMMA and test its resistance to the different forces present in a fracture. Forty-eight (48 3.5MM x 4-hole DCP were made from an alginate mold. Six (6 femurs were obtained from canine cadavers zeighing from 10 to 20 kg, which underwent osteotomy simulating an oblique fracture. The plates were subsequently positioned in the osteotomized bones to submit them to the various forces involved in a fracture. The DCP-PMMA resisted a torque force of 2.83 newton/metres and a compression and flexion force of 0.21 kilonewton. The obtained resistance of the DCP-PMMA was an average of 20 kg per force. The results of this study show that it is possible to make a DCP-PMMA 3.5 mm x 4-hole, the resistance of which is of 20 kg against the three applied forces, and that it can be used to stabilize long bone fractures subjected to a pressure of less than 20 kg.

  12. Electrical characterization of graphene oxide and organic dielectric layers based on thin film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Karteri, İbrahim, E-mail: ibrahimkarteri@gmail.com [Department of Materials Science And Engineering, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Karataş, Şükrü [Department of Physics, Kahramanmaras Sutcu Imam University, Kahramanmaraş 4610 (Turkey); Yakuphanoğlu, Fahrettin [Department of Physics, Fırat University, Elazıg 2310 (Turkey)

    2014-11-01

    Highlights: • We report the synthesis of graphene oxide nanosheets and electrical characterization of graphene oxide based thin film transistor. • Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. • We used insulator layers which are polymethylmethacrylate (PMMA) and polyvinyl phenol (PVP) for graphene oxide based thin flim transistor. - Abstract: We have studied the electrical characteristics of graphene oxide based thin flim transistor with the polymer insulators such as polymethyl methacrylate (PMMA) and poly-4-vinylphenol (PVP). Graphene oxide (GO) nanosheets were prepared by using modified Hummers method. The structural properties of GO nanosheets were characterized with Ultraviolet Visible (UV–vis), FT-IR spectroscopy and X-rays diffraction (XRD). Graphene oxide based thin flim transistor (GO-TFT) was prepared by a spin-coating and thermal evaporation technique. The electrical characterization of GO-TFT was analyzed by output and transfer characteristics by using Keithley-4200 semiconductor characterization system (SCS). The graphene oxide based thin flim transistor devices show p-type semiconducting behavior. The mobility, threshold voltage, sub-threshold swing value and I{sub on}/I{sub off} of GO-TFT were found to be 0.105 cm{sup 2} V{sup −1} s{sup −1}, −8.7 V, 4.03 V/decade and 10, respectively.

  13. Lithium Polymer Electrolytes Based On PMMA / PEG And Penetrant Diffusion In Kraton Penta-Block Ionomer

    Science.gov (United States)

    Meng, Yan

    The study of diffusion in polymeric material is critical to many research fields and applications, such as polymer morphology, protective coatings (paints and varnishes), separation membranes, transport phenomena, polymer electrolytes, polymer melt, and controlled release of drugs from polymer carriers [1-9]. However, it is still a challenge to understand, predict and control the diffusion of molecules and ions of different sizes in polymers [2]. This work studied the medium to long range diffusion of species (i.e., ions and molecules) in solid polymer electrolytes based on poly(ethylene glycol)/poly(methyl methacrylate) (PEG/PMMA) for Li-based batteries, and polymeric permselective membranes via pulsed-field gradient NMR and a.c. impedance. Over the past decades polymer electrolytes have attracted much attention because of their promising technological application as an ion-conducting medium in solid-state batteries, fuel cells, electrochromic displays, and chemical sensors [10, 11]. However, despite numerous studies related to ionic transport in these electrolytes the understanding of the migration mechanism is still far from being complete, and progress in the field remains largely empirical [10, 12-15]. Among various candidates for solid polymer electrolyte (SPE) material, the miscible polymer pair, poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA), is an attractive one, because there is a huge difference in mobility between PEO and PMMA in their blends, and PEO chains remain exceptionally mobile in the blend even at temperature below the glass transition temperature of the blend [ 16]. Thus the mechanical strength and dimensional stability is maintained by PMMA component, while the chain motions or rearrangements of the PEO component virtually contribute to the ion transport [17]. The current work prepared two types of SPE based on poly(ethylene glycol) (PEG) /PMMA (40/60 by weight) for Li-based batteries: lithium bis(trifluoromethylsulfonylimide) (Li

  14. Nonlinear optical properties of poly(methyl methacrylate) thin films doped with Bixa Orellana dye

    Science.gov (United States)

    Zongo, S.; Kerasidou, A. P.; Sone, B. T.; Diallo, A.; Mthunzi, P.; Iliopoulos, K.; Nkosi, M.; Maaza, M.; Sahraoui, B.

    2015-06-01

    Natural dyes with highly delocalized π-electron systems are considered as promising organic materials for nonlinear optical applications. Among these dyes, Bixa Orellana dye with extended π-electron delocalization is one of the most attractive dyes. Bixa Orellana dye-doped Poly(methyl methacrylate) (PMMA) thin films were prepared through spin coating process for linear and nonlinear optical properties investigation. Atomic force microscopy (AFM) was used to evaluate the roughness of the thin films. The optical constants n and k were evaluated by ellipsometric spectroscopy. The refractive index had a maximum of about 1.456 at 508.5, 523.79 and 511.9 nm, while the maximum of k varies from 0.070 to 0.080 with the thickness. The third order nonlinear optical properties of the hybrid Bixa Orellana dye-PMMA polymer were investigated under 30 ps laser irradiation at 1064 nm with a repetition rate of 10 Hz. In particular the third-order nonlinear susceptibility has been determined by means of the Maker Fringes technique. The nonlinear third order susceptibility was found to be 1.00 × 10-21 m2 V-2 or 0.72 × 10-13 esu. Our studies provide concrete evidence that the hybrid-PMMA composites of Bixa dye are prospective candidates for nonlinear material applications.

  15. Study of indium tin oxide thin films deposited on acrylics substrates by Ion beam assisted deposition technique

    OpenAIRE

    Meng Lijian; Liang Erjun; Gao Jinsong; Teixeira, Vasco M. P.; Santos, M. P. dos

    2009-01-01

    Indium tin oxide (ITO) thin films have been deposited onto acrylics (PMMA) substrates by ion beam assisted deposition technique at different oxygen flows. The structural, optical and electrical properties of the deposited films have been characterized by X-ray diffraction, transmittance, FTIR, ellipometry and Hall effect measurements. The optical constants of the deposited films have been calculated by fitting the ellipsometric spectra. The effects of the oxygen flow on the properties of the ...

  16. The influences of N-acetyl cysteine (NAC on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA-based dental resin

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    2015-04-01

    Full Text Available Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA dental resins.Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%. MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR. Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively.Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%.Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties.

  17. The influences of N-acetyl cysteine (NAC) on the cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA)-based dental resin.

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Li, Jing; Shan, Lequn; Yang, Yanwei; Li, Meng; Chen, Jihua

    2015-01-01

    Objectives. This study aimed to investigate the influences of N-acetyl cysteine (NAC) on cytotoxicity and mechanical properties of Poly-methylmethacrylate (PMMA) dental resins. Methods. Experimental PMMA resin was prepared by incorporating various concentrations of NAC (0, 0.15, 0.3, 0.6 and 0.9 wt.%). MTT assay was performed to investigate viability of human dental pulp cells after exposure to extract of PMMA resin with or without NAC. Cell adhesion on resin specimens was examined with scanning electron microscopy. Degree of conversion was studied with Fourier Transform Infrared Spectroscopy (FTIR). Flexural strength, microhardness and surface roughness was evaluated using a universal testing machine, microhardness tester and optical profilometer, respectively. Results. Incorporation of NAC into PMMA resin significantly reduced its cytotoxicity and enhanced cell adhesion on its surface. NAC induced negative influences on the mechanical and physical properties of PMMA resin in a dose-dependent manner. The degree of conversion for all experimental PMMA resins reached as high as 72% after 24 h of polymerization. All the tested properties were maintained when the concentration of incorporated NAC was 0.15 wt.%. Conclusion. The addition of 0.15 wt.% NAC remarkably improved biocompatibility of PMMA resin without exerting significant negative influence on its mechanical and physical properties.

  18. Study on Mechanical Properties of the Nanometer(PMMA/Montmorillonite)Composite Denture Base%纳米(PMMA/蒙托土)义齿基托复合材料力学性能的研究

    Institute of Scientific and Technical Information of China (English)

    杨俊; 李志安; 李四群

    2006-01-01

    目的:研究蒙托土对聚甲基丙烯酸甲酯(PMMA)义齿基托力学性能的改善.方法:将有机蒙托土按2.64%、3.89%、5.56%、6.92%的质量比加入聚甲基丙烯酸甲酯(PMMA)粉中,制成不同浓度的纳米(PMMA/蒙托土)义齿基托复合材料,对各组的挠曲弹性模量、挠曲强度进行检测,并对结果进行统计学分析.结果:添加蒙托土为2.64%、3.89%(质量比)的纳米(PMMA/蒙托土)义齿基托与普通PMMA义齿基托相比,挠曲弹性模量有所提高(P0.05).添加蒙托土为5.56%(质量比)的纳米(PMMA/蒙托土)义齿基托与普通PMMA义齿基托相比,挠曲弹性模量、挠曲强度均没有显著性差异(P>0.05).添加蒙托土为6.92%(质量比)的纳米(PMMA/蒙托土)义齿基托与普通PMMA义齿基托相比,挠曲弹性模量没有显著性差异(P>0.05),挠曲强度下降(P<0.05).结论:在聚甲基丙烯酸甲酯义齿基托中添加一定质量比有机蒙托土在不影响其挠曲强度的条件下可以改善其挠曲弹性模量.

  19. Polymer-ZnO nanocomposites foils and thin films for UV protection

    Energy Technology Data Exchange (ETDEWEB)

    Shanshool, Haider Mohammed; Yahaya, Muhammad; Abdullah, Ibtisam Yahya [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Yunus, Wan Mahmood Mat [Department of Physics, Faculty of Science, University Putra Malaysia, 43400 UPM, Serdang (Malaysia)

    2014-09-03

    The damage of UV radiation on human eye and skin is extensively studied. In the present work, the nanocomposites foils and thin films have been prepared by using casting method and spin coating, respectively. Nanocomposites were prepared by mixing ZnO nanoparticles with Polymethyl methacrylate (PMMA) and Polyvinylidene fluoride (PVDF) as polymer matrix. Different contents of ZnO nanoparticles were used as filler in the nanocomposites. UV-Vis spectra showed very low transmittance in UV region that decreases with increase content of ZnO. PVDF/ZnO samples showed the lowest transmittance. The rough surface of PVDF was observed from SEM image. While a homogeneous dispersion of ZnO nanoparticles in PMMA were indicated by FESEM images.

  20. Thin book

    DEFF Research Database (Denmark)

    En lille bog om teater og organisationer, med bidrag fra 19 teoretikere og praktikere, der deltog i en "Thin Book Summit" i Danmark i 2005. Bogen bidrager med en state-of-the-art antologi om forskellige former for samarbejde imellem teater og organisationer. Bogen fokuserer både på muligheder og...

  1. Preparation of Oleyl Phosphate-Modified TiO2/Poly(methyl methacrylate Hybrid Thin Films for Investigation of Their Optical Properties

    Directory of Open Access Journals (Sweden)

    Masato Fujita

    2015-01-01

    Full Text Available TiO2 nanoparticles (NPs modified with oleyl phosphate were synthesized through stable Ti–O–P bonds and were utilized to prepare poly(methyl methacrylate- (PMMA- based hybrid thin films via the ex situ route for investigation of their optical properties. After surface modification of TiO2 NPs with oleyl phosphate, IR and 13C CP/MAS NMR spectroscopy showed the presence of oleyl groups. The solid-state 31P MAS NMR spectrum of the product revealed that the signal due to oleyl phosphate (OP shifted upon reaction, indicating formation of covalent Ti–O–P bonds. The modified TiO2 NPs could be homogeneously dispersed in toluene, and the median size was 16.1 nm, which is likely to be sufficient to suppress Rayleigh scattering effectively. The TEM images of TiO2/PMMA hybrid thin films also showed a homogeneous dispersion of TiO2 NPs, and they exhibited excellent optical transparency even though the TiO2 content was 20 vol%. The refractive indices of the OP-modified TiO2/PMMA hybrid thin films changed higher with increases in TiO2 volume fraction, and the hybrid thin film with 20 vol% of TiO2 showed the highest refractive index (n = 1.86.

  2. Comparison of bacterial adhesion to dental materials of polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) using atomic force microscopy and scanning electron microscopy.

    Science.gov (United States)

    Fang, Jie; Wang, Chuanyong; Li, Yifei; Zhao, Zhihe; Mei, Li

    2016-11-01

    The aim of this study was to compare the bacterial adhesion to denture materials of polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) using atomic force microscopy and scanning electron microscopy. The adhesion forces of living Streptococcus sanguinis and Streptococcus mutans to PET and PMMA were directly measured using atomic force microscopy (AFM) in liquid. Streptococcal biofilms formed on the two material surfaces were investigated and compared using scanning electron microscopy (SEM) and colony-forming units (CFU) counting. Surface roughness and hydrophobicity of PET and PMMA were also measured. The results showed that PET surfaces were significantly smoother and more hydrophilic than PMMA surfaces both with and without a salivary film (p SCANNING 38:665-670, 2016. © 2016 Wiley Periodicals, Inc.

  3. Effect of surface mechanical finishes on charging ability of electron irradiated PMMA in a scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Rondot, Sebastien, E-mail: sebastien.rondot@univ-reims.fr [Groupe de Recherche en Sciences pour l' Ingenieur, EA4301, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2 (France); Jbara, Omar [Groupe de Recherche en Sciences pour l' Ingenieur, EA4301, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2 (France); Fakhfakh, Slim [LaMaCop, Faculte des Sciences de SFAX, Route Soukra Km 3, BP 1171, C.P 3000 Sfax (Tunisia); Belkorissat, Redouane; Patat, Jean Marc [Groupe de Recherche en Sciences pour l' Ingenieur, EA4301, Faculte des Sciences, BP 1039, 51687 Reims Cedex 2 (France)

    2011-10-01

    Charging of Polymethyl Methacrylate insulators (PMMA), in a scanning electron microscope (SEM) is studied owing to a time resolved current method. This method allows the evolution of trapped charge versus time and the charging time constant to be deduced. The effect of surface roughness change on the ability of PMMA to trapped charge is highlighted. The results show that the trapped charge at the steady state decreases when the roughness increases in the micrometer range while the time constant of charging increases with surface roughness. This behaviour is due to the increase of leakage current and/or enhanced secondary electron emission (SEE). On the one hand, surface mechanical finishes allows, the build up charge in insulators submitted to an electron bombardment to be lowered. On the other hand this treatment allows the secondary electron emission to be raised for some specific applications.

  4. Síntesis de copolímeros de PS-b-PMMA empleando polimerización radicalaria controlada

    Directory of Open Access Journals (Sweden)

    Vivina Hanazumi

    2016-01-01

    Full Text Available Se estudió la síntesis de copolímeros bloque de poli (estireno y poli (metil metacrilato (PS-b-PMMA empleando polimerización radicalaria por transferencia atómica (ATRP. Se realizaron distintos experimentos variando las relaciones molares de monómero, ligando e iniciador para determinar su influencia en la síntesis de copolímeros PS-b-PMMA con masas molares determinadas y estructura homogénea. Los polímeros sintetizados se caracterizaron químicamente por espectroscopia infrarroja con Transformada de Fourier (FTIR y cromatografía por exclusión de tamaños (SEC, empleando un detector de índice de refracción. Se obtuvieron los copolímeros bloque propuestos, con un buen control de su estructura macromolecular (Mw/Mn < 1,90.

  5. Rapid fabrication of a four-layer PMMA-based microfluidic chip using CO2-laser micromachining and thermal bonding

    Science.gov (United States)

    Chen, Xueye; Shen, Jienan; Zhou, Mengde

    2016-10-01

    A smart design method to transform the original two-layer microfluidic chip into a four-layer 3D microfluidic chip is proposed. A novel fabrication method is established to rapidly and effectively produce a four-layer microfluidic chip device made entirely from polymethylmethacrylate (PMMA). Firstly, the CO2-laser cuts the PMMA sheets by melting and blowing away vaporized material from the parent material to obtain high-quality channels of the microfluidic chip. An orthogonal experimental method is used to study its processing stability. In addition, a simple, rapid thermal bonding technique is successfully applied in fabricating the four-layer microfluidic chip, which has a bond strength of 1.3 MPa. A wooden pole is used to improve the accuracy of the alignment. Finally, a mixing experiment with blue ink and water is carried out, which proves that this smart design method and rapid manufacturing technology are successful.

  6. Graphite and PMMA as pore formers for thermoplastic extrusion of porous 3Y-TZP oxygen transport membrane supports

    DEFF Research Database (Denmark)

    Bjørnetun Haugen, Astri; Gurauskis, Jonas; Kaiser, Andreas

    2016-01-01

    with gas permeability exceeding the target of 10−14m2 are obtained. In the temperature range 1250–1400°C the support gas permeability is insensitive to the sintering temperature, and the feedstocks shrink more than 15% during sintering, making them ideal for co-sintering with functional OTM layers......A gas permeable porous support is a crucial part of an asymmetric oxygen transport membrane (OTM). Here, we develop feedstocks for thermoplastic extrusion of tubular, porous 3Y-TZP (partially stabilized zirconia polycrystals, (Y2O3)0.03(ZrO2)0.97)) ceramics, using graphite and/or polymethyl...... methacrylate (PMMA) as pore formers. The influence of pore former content and type, 3Y-TZP particle size and support sintering temperature on the microstructure, porosity and gas permeability were studied. Using at least 40 vol% pore former, consisting of graphite and PMMA in the volume ratio 2:1, tubes...

  7. Effect of annealing temperature on the morphology and optical properties of PMMA films by spin-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Aadila, A., E-mail: aadilaazizali@gmail.com; Afaah, A. N.; Asib, N. A. M. [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Mohamed, R.; Rusop, M. [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); NANO-Electronic Centre, Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Khusaimi, Z., E-mail: zurai142@salam.uitm.edu.my [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2016-07-06

    Poly(methyl methacrylate) (PMMA) films were deposited on glass substrate by sol-gel spin-coating method. The films were annealed for 10 minutes in furnace at different annealing temperature of room temperature, 50, 100, 150 and 200 °C. The effect of annealing temperatures to the surface and optical properties of PMMA films spin-coated on the substrate were investigated by Atomic Force Microscope (AFM) and Ultraviolet-Visible (UV-Vis) Spectroscopy. It was observed in AFM analysis all the annealed films show excellent smooth surface with zero roughness. All the samples demonstrate a high transmittance of 80% in UV region as shown in UV-Vis measurement. Highly transparent films indicate the films are good optical properties and could be applied in various optical applications and also in non-linear optics.

  8. Synthesis of superparamagnetic Fe3O4/PMMA/SiO2 nanorattles with periodic mesoporous shell for lysozyme adsorption

    Science.gov (United States)

    Lan, Fang; Hu, Hao; Jiang, Wen; Liu, Kexia; Zeng, Xiaobo; Wu, Yao; Gu, Zhongwei

    2012-03-01

    A new kind of nanorattle, composed of a Fe3O4/polymethyl methacrylate (PMMA) composite nanospherical core and mesoporous SiO2 shell, has been successfully synthesized with the combination of a modified stöber method and a dual-template strategy, followed by alcohol dialysis. The nanorattles showed high efficiency in protein adsorption and separation.A new kind of nanorattle, composed of a Fe3O4/polymethyl methacrylate (PMMA) composite nanospherical core and mesoporous SiO2 shell, has been successfully synthesized with the combination of a modified stöber method and a dual-template strategy, followed by alcohol dialysis. The nanorattles showed high efficiency in protein adsorption and separation. Electronic supplementary information (ESI) available: Experimental details, SAXRD pattern. See DOI: 10.1039/c2nr12125e

  9. Effect of annealing temperature on the morphology and optical properties of PMMA films by spin-coating method

    Science.gov (United States)

    Aadila, A.; Afaah, A. N.; Asib, N. A. M.; Mohamed, R.; Rusop, M.; Khusaimi, Z.

    2016-07-01

    Poly(methyl methacrylate) (PMMA) films were deposited on glass substrate by sol-gel spin-coating method. The films were annealed for 10 minutes in furnace at different annealing temperature of room temperature, 50, 100, 150 and 200 °C. The effect of annealing temperatures to the surface and optical properties of PMMA films spin-coated on the substrate were investigated by Atomic Force Microscope (AFM) and Ultraviolet-Visible (UV-Vis) Spectroscopy. It was observed in AFM analysis all the annealed films show excellent smooth surface with zero roughness. All the samples demonstrate a high transmittance of 80% in UV region as shown in UV-Vis measurement. Highly transparent films indicate the films are good optical properties and could be applied in various optical applications and also in non-linear optics.

  10. The influence of radiation and light on Ps formation in PMMA and PE studied by coincidence Doppler-broadening spectroscopy

    CERN Document Server

    Suzuki, T; Shantarovich, V; Kondo, K; Hamada, E; Matso, M; Ma Li; Ito, Y

    2003-01-01

    Using two Ge detectors, the high-resolution Doppler-broadening energy spectra of positron annihilation gamma rays has been obtained by measuring the coincidences of the two photons. Light bleaching and oxygen effects on positron annihilation were investigated in this way. A large enhancement of the high-momentum part of the coincidence Doppler spectra was observed in poly(methylmethacrylate) (PMMA), which contains oxygen atoms in the polymer structure. Bleaching experiments in PMMA and in copolymer ethylene-methylmethacrylate EMMA (LDPE+MMA 3 mol%) have demonstrated that the enhancement effect may be due to the trapping of positrons by the polar -C sup + 6-O sup - groups, followed by positron annihilation with the electrons belonging to oxygen.

  11. High energy ion irradiation effects on polymer materials. LET dependence of G value of scission of polymethylmethacrylate (PMMA)

    Energy Technology Data Exchange (ETDEWEB)

    Kudoh, H.; Sasuga, T.; Seguchi, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Linear energy transfer (LET) dependence on the probability of main chain scission of polymethylmethacrylate (PMMA) was investigated. The probability was obtained from decreases in molecular weight measured by the gel permeation chromatography (GPC), and LET was evaluated by TRIM code. The scission probability as a function of LET was almost constant in the low LET, and decreased in the high LET ion irradiation. The mechanism was interpreted from the model of spur-overlapping along an ion`s path. (author)

  12. CT fluoroscopy-guided percutaneous vertebroplasty in spinal malignancy: technical results, PMMA leakages, and complications in 202 patients

    Energy Technology Data Exchange (ETDEWEB)

    Trumm, Christoph G.; Pahl, Anne; Zech, Christoph J.; Stahl, Robert; Paprottka, Philipp M.; Sandner, Torleif A.; Reiser, Maximilian F. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen-Grosshadern, Department of Clinical Radiology, Munich (Germany); Helmberger, Thomas K. [Klinikum Bogenhausen, Institute for Diagnostic and Interventional Radiology and Nuclear Medicine, Muenchen (Germany); Jakobs, Tobias F. [Krankenhaus Barmherzige Brueder Muenchen, Department of Radiology, Muenchen (Germany); Hoffmann, Ralf-Thorsten [Universitaetsklinikum Carl Gustav Carus Dresden, Department and Policlinics of Diagnostic Radiology, Dresden (Germany)

    2012-11-15

    To retrospectively evaluate the incidence and clinical impact of local polymethylmethacrylate (PMMA) leaks and pulmonary cement embolisms occurring under CT fluoroscopy-guided vertebroplasty of symptomatic malignant vertebral osteolyses. From December 2001 to June 2009, 202 cancer patients (116 women, 86 men; age 63.2 {+-} 8.6 years) with painful malignant vertebral osteolyses underwent vertebroplasty, with or without vertebral compression fracture. A total of 331 vertebrae were treated in 231 sessions under CT fluoroscopy guidance (120kV; 10-25mA; single slice, 4-, 16-, and 128-row CT). In the pre-vertebroplasty CT, the following items were assessed: osteolytic destruction (0, {<=}25, {<=}50, {<=}75, or {<=}100%) of vertebral cross-sectional area, posterior wall, and circumference; presence of perivertebral and degree of epidural (no, mild, moderate) soft tissue involvement. Local PMMA leaks were analyzed using the post-vertebroplasty CT. Pulmonary cement embolisms were evaluated in all patients having undergone radiography (CR; n = 53) or CT (n = 88) of the chest after vertebroplasty due to their underlying disease. Patient charts were reviewed regarding adverse events. Of 331 treated vertebrae, 32, 20.2, and 15.7% showed more than 50% osteolytic involvement of the vertebral cross-sectional area, posterior wall, and circumference, respectively. Mild or moderate epidural involvement was seen in 13.0 and 8.4%. Local PMMA leakage rate was 58.6% (194 of 331 vertebrae). Pulmonary cement embolisms (segmental, n = 10; central, n = 1) were seen after 7.8% of the procedures with follow-up imaging of the chest. No major complications occurred within a 30-day period after vertebroplasty. Vertebroplasty of spinal malignancy can be safely performed under CT fluoroscopy guidance even in patients with substantial osteolytic involvement. In our patient collective, PMMA leaks and pulmonary cement embolisms visualized in post-procedural radiography and CT images had no clinical

  13. A Comparative Study on Graphene Oxide and Carbon Nanotube Reinforcement of PMMA-Siloxane-Silica Anticorrosive Coatings.

    Science.gov (United States)

    Harb, Samarah V; Pulcinelli, Sandra H; Santilli, Celso V; Knowles, Kevin M; Hammer, Peter

    2016-06-29

    Carbon nanotubes (CNTs) and graphene oxide (GO) have been used to reinforce PMMA-siloxane-silica nanocomposites considered to be promising candidates for environmentally compliant anticorrosive coatings. The organic-inorganic hybrids were prepared by benzoyl peroxide (BPO)-induced polymerization of methyl methacrylate (MMA) covalently bonded through 3-(trimethoxysilyl)propyl methacrylate (MPTS) to silica domains formed by hydrolytic condensation of tetraethoxysilane (TEOS). Single-walled carbon nanotubes and graphene oxide nanosheets were dispersed by surfactant addition and in a water/ethanol solution, respectively. These were added to PMMA-siloxane-silica hybrids at a carbon (CNT or GO) to silicon (TEOS and MPTS) molar ratio of 0.05% in two different matrices, both prepared at BPO/MMA molar ratios of 0.01 and 0.05. Atomic force microscopy and scanning electron microscopy showed very smooth, homogeneous, and defect-free surfaces of approximately 3-7 μm thick coatings deposited onto A1020 carbon steel by dip coating. Mechanical testing and thermogravimetric analysis confirmed that both additives CNT and GO improved the scratch resistance, adhesion, wear resistance, and thermal stability of PMMA-siloxane-silica coatings. Results of electrochemical impedance spectroscopy in 3.5% NaCl solution, discussed in terms of equivalent circuits, showed that the reinforced hybrid coatings act as a very efficient anticorrosive barrier with an impedance modulus up to 1 GΩ cm(2), approximately 5 orders of magnitude higher than that of bare carbon steel. In the case of GO addition, the high corrosion resistance was maintained for more than 6 months in saline medium. These results suggest that both carbon nanostructures can be used as structural reinforcement agents, improving the thermal and mechanical resistance of high performance anticorrosive PMMA-siloxane-silica coatings and thus extending their application range to abrasive environments.

  14. Finite element modelling of rheological and penetration characteristics of curing PMMA bone cement in total hip replacement

    OpenAIRE

    2006-01-01

    This thesis is concerned with the study of the rheological properties of PMMA bone cement that is used as a grout for bone and prosthesis in THR and TKR Interdigitation of bone cement through porous cancellous bone depends on the rheological characteristics of bone cement and porosity of the cancellous bone. The rheological characteristics of the bone cement are thus an important factor effecting the optimum penetration of bone cement through cancellous bone. In this project the rheologic...

  15. Experimental ex-vivo validation of PMMA-based bone cements loaded with magnetic nanoparticles enabling hyperthermia of metastatic bone tumors

    Directory of Open Access Journals (Sweden)

    Mariem Harabech

    2017-05-01

    Full Text Available Percutaneous vertebroplasty comprises the injection of Polymethylmethacrylate (PMMA bone cement into vertebrae and can be used for the treatment of compression fractures of vertebrae. Metastatic bone tumors can cause such compression fractures but are not treated when injecting PMMA-based bone cement. Hyperthermia of tumors can on the other hand be attained by placing magnetic nanoparticles (MNPs in an alternating magnetic field (AMF. Loading the PMMA-based bone cement with MNPs could both serve vertebra stabilization and metastatic bone tumor hyperthermia when subjecting this PMMA-MNP to an AMF. A dedicated pancake coil is designed with a self-inductance of 10 μH in series with a capacitance of 0.1 μF that acts as resonant inductor-capacitor circuit to generate the AMF. The thermal rise is appraised in beef vertebra placed at 10 cm from the AMF generating circuit using optical temperatures sensors, i.e. in the center of the PMMA-MNP bone cement, which is located in the vicinity of metastatic bone tumors in clinical applications; and in the spine, which needs to be safeguarded to high temperature exposures. Results show a temperature rise of about 7 °C in PMMA-MNP whereas the temperature rise in the spine remains limited to 1 °C. Moreover, multicycles heating of PMMA-MNP is experimentally verified, validating the technical feasibility of having PMMA-MNP as basic component for percutaneous vertebroplasty combined with hyperthermia treatment of metastatic bone tumors.

  16. 聚甲基丙烯酸甲酯/Laponite复合材料制备及表征%Preparation and Properties of PMMA/Laponite Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    董志; 吴文涛; 余坚; 李妍妍; 卢茂骥

    2014-01-01

    通过溶剂交换法将Laponite从水中转移到N,N二甲基乙酰胺(DMAC)中,辅助以超声波作用使Laponite与聚甲基丙烯酸甲酯(PMMA)溶液进行共混复合制备PMMA/Laponite复合材料,并表征其相关性能.

  17. Novel acrylic resin denture base with enhanced mechanical properties by the incorporation of PMMA-modified hydroxyapatite

    Institute of Scientific and Technical Information of China (English)

    Yingying Pan; Fengwei Liu; Dan Xu; Xiaoze Jiang; Hao Yu; Meifang Zhu

    2013-01-01

    A kind of novel acrylic resin denture base enhanced by PMMA-modified hydroxyapatite (M-HAP) was prepared and the modification effect of HAP on the mechanical properties of denture base material was investigated in the present study. HAP whiskers were prepared by hydrothermal homogeneous precipitation process and were silanized by the coupling agent, 3-methacryloxy propyl trimethoxyl silane (g-MPS), to induce the vinyl groups onto its surface. Methyl methacrylate (MMA) were then modified outside the vinyl functionalized HAP via polymerization to build a similar chemical structure with the acrylic matrix. A novel acrylic resin denture base was obtained through self-curing process with the incorporation of this PMMA-modified HAP, and the content of which ranged from 0 wt% to 0.8 wt%. Thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and universal testing apparatus were used to characterize M-HAP and corresponding denture base. The results showed that PMMA were successfully grafted onto the surface of HAP whiskers with up to 15 wt% and the modification turned out to be useful for the dispersion and compatibility of whiskers in the acrylic resin matrix. The mechanical properties of the prepared denture base samples were enhanced greatly after incorporating with M-HAP fillers. The optimal incorporated content of M-HAP was also investigated.

  18. Use of the {sup 14}C-PMMA and He-gas methods to characterise excavation disturbance in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Autio, J.; Kirkkomaeki, T. [Saanio and Riekkola Oy, Helsinki (Finland); Siitari-Kauppi, M. [University of Helsinki (Finland). Lab. of Radiochemistry; Timonen, J.; Laajalahti, M.; Aaltonen, T.; Maaranen, J. [University of Jyvaeskylae (Finland). Dept. of Physics

    1999-04-01

    Characterisation of the excavation disturbance caused by boring of experimental full-scale deposition holes in the Research Tunnel at Olkiluoto was carried out successfully by using two novel methods; the {sup 14}C-PMMA and He-gas methods, which were modified and applied for the first time in this type of study. The experience obtained implies that the techniques are feasible and can be used to study similar types of rock excavation disturbance such as that caused by boring with mini discs, a technique which will be used in the underground Hard Rock Laboratory at Aespoe during late 1998 and early 1999. Both of the measurement methods have been in continuous use and the work has included development of both the measuring and interpretation techniques. Use of the {sup 14}C-PMMA method is suggested for studies of rock structure and the spatial distribution of porosity. The {sup 14}C-PMMA method also provides quantitative information about nanometer-range porosity which is beyond the scope of most standard methods of microscopic investigation. The use of He-gas methods are proposed for determining the diffusion coefficient, permeability and complementary porosity of rock samples taken from the disturbed zone. (orig.) 23 refs.

  19. Fabrication of 3D embedded hollow structures inside polymer dielectric PMMA with femtosecond laser

    Science.gov (United States)

    Zheng, Chong; Chen, Tao; Hu, Anming; Liu, Shibing; Li, Junwei

    2016-11-01

    Recent progresses in femtosecond laser (fs) manufacturing have already proved that fs laser is a powerful tool in three dimensional internal structure fabrications. However, most studies are mainly focused on realize such structures in inorganic transparent dielectric, such as photosensitive glass and fused silica, etc. In this study, we present two methods to fabricate embedded internal 3D structures in a polymer dielectric material polymethyl methacrylate (PMMA). Both continuous hollow structure such as microfluidic channels and discrete hollow structures such as single microcavities are successfully fabricated with the help of femtosecond lasers. Among them, complicated 3D microchannel with a total length longer than 10mm and diameters around 80μm to 200μm are fabricated with a low repetition rate Ti: sapphire femtosecond laser by direct laser writing at a speed ranging from 25μm/s to 2000μm/s microcavities which function as concave microball lenses (CMBLs) and can be applied in super-wide-angle imaging are fabricated with a high repetition rate femtosecond fiber laser due to the distinct heat accumulation effect after 5s irradiation with the tightly focused fs laser beam. These new approaches proved that femtosecond laser direct writing technology has great application potential in 3D integrated devices manufacturing in the future.

  20. Urea decreases specific ion effects on the LCST of PMMA-block-PDMAEMA aggregates

    Directory of Open Access Journals (Sweden)

    João Carlos Perbone de Souza

    2014-12-01

    Full Text Available Urea is a well-known additive used as a mild protein denaturant. The effect of urea on proteins, micellar systems and other colloids is still under debate. In particular, urea has shown interesting effects on the ion binding in systems like charged micelles, vesicles or Langmuir-Blodgett films. The urea effect on polymeric aggregates in water is still an open field. For instance, the additive may affect properties such as cmc, LCST, UCST and others. In particular, LCST is a property that can be very convenient for designing smart systems that respond to temperature. Previous studies have indicated that the LCST of positive charged copolymers aggregates based on poly[N-dimethyl(ethylamine methacrylate], PDMAEMA, can be nicely modulated by anions in aqueous solution and such phenomenon depends on the nature of the anion present. In this work, it has been demonstrated that urea also affects the LCST of PMMA-block-PDMAEMA aggregates in aqueous solution. In addition, in the presence of high concentrations of the additive, the specific behavior of the anions is lost, supporting the general mechanism of urea reducing the differences on ion binding to surfaces in aqueous solutions. To the best of our knowledge, this is the first time those phenomena are shown in polymer micelles.

  1. UV Radiation Detection Using Optical Sensor Based on Eu3+ Doped PMMA

    Directory of Open Access Journals (Sweden)

    Miluski Piotr

    2016-12-01

    Full Text Available Progress in UV treatment applications requires new compact and sensor constructions. In the paper a hybrid (organic-inorganic rare-earth-based polymeric UV sensor construction is proposed. The efficient luminescence of poly(methyl methacrylate (PMMA matrix doped by europium was used for testing the optical sensor (optrode construction. The europium complex assures effective luminescence in the visible range with well determined multi-peak spectrum emission enabling construction of the optrode. The fabricated UV optical fibre sensor was used for determination of Nd:YAG laser intensity measurements at the third harmonic (355 nm in the radiation power range 5.0-34.0 mW. The multi-peak luminescence spectrum was used for optimization of the measurement formula. The composition of luminescent peak intensity enables to increase the slope of sensitivity up to −2.8 mW-1. The obtained results and advantages of the optical fibre construction enable to apply it in numerous UV detection systems.

  2. Modified Regression Rate Formula of PMMA Combustion by a Single Plane Impinging Jet

    Directory of Open Access Journals (Sweden)

    Tsuneyoshi Matsuoka

    2017-01-01

    Full Text Available A modified regression rate formula for the uppermost stage of CAMUI-type hybrid rocket motor is proposed in this study. Assuming a quasi-steady, one-dimensional, an energy balance against a control volume near the fuel surface is considered. Accordingly, the regression rate formula which can calculate the local regression rate by the quenching distance between the flame and the regression surface is derived. An experimental setup which simulates the combustion phenomenon involved in the uppermost stage of a CAMUI-type hybrid rocket motor was constructed and the burning tests with various flow velocities and impinging distances were performed. A PMMA slab of 20 mm height, 60 mm width, and 20 mm thickness was chosen as a sample specimen and pure oxygen and O2/N2 mixture (50/50 vol.% were employed as the oxidizers. The time-averaged regression rate along the fuel surface was measured by a laser displacement sensor. The quenching distance during the combustion event was also identified from the observation. The comparison between the purely experimental and calculated values showed good agreement, although a large systematic error was expected due to the difficulty in accurately identifying the quenching distance.

  3. Creation of 3D microsculptures in PMMA by multiple angle proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Andrea, T., E-mail: tobias.andrea@physik.uni-leipzig.de [Institute for Experimental Physics II, Nuclear Solid State Physics, Faculty of Physics and Geosciences, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Rothermel, M. [Institute for Experimental Physics II, Nuclear Solid State Physics, Faculty of Physics and Geosciences, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Reinert, T. [Institute for Experimental Physics II, Nuclear Solid State Physics, Faculty of Physics and Geosciences, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany); Department of Physics, 1155 Union Circle, 311427, University of North Texas, Denton, TX 76203 (United States); Koal, T.; Butz, T. [Institute for Experimental Physics II, Nuclear Solid State Physics, Faculty of Physics and Geosciences, University of Leipzig, Linnestr. 5, 04103 Leipzig (Germany)

    2011-10-15

    In recent years the technique of proton beam writing has established itself as a versatile method for the creation of microstructures in resist materials. While these structures can be almost arbitrary in two dimensions, the creation of genuine 3D structures remains a challenge. At the LIPSION accelerator facility a new approach has been developed which combines aspects of ion beam tomography, so far solely an analysis method, with proton beam writing. Key element is the targeted irradiation from multiple angles in order to obtain a much broader range of 3D microstructures than has hitherto been possible. PMMA columns with a diameter of {approx}90 {mu}m were used as raw material and placed in an upright position on top of a rotational axis. Using 2.25 MeV protons patterns corresponding to the silhouettes of the desired structures were written from two or more directions. In a subsequent step of chemical etching irradiated portions were dissolved, leaving behind the finished 3D sculpture. Various objects have been created. For the demonstration of the method a 70 {mu}m high model of the Eiffel tower has been sculpted by irradiation from two angles. Using irradiation from three angles a 40 {mu}m wide screw with right-handed thread could be crafted which might find applications in micromachining. Also, a cage structure with a pore size of ca. 20 {mu}m was written with the intention to use it as a scaffold for the growth of biological cells.

  4. 3D homogeneity study in PMMA layers using a Fourier domain OCT system

    Science.gov (United States)

    Briones-R., Manuel de J.; Torre-Ibarra, Manuel H. De La; Tavera, Cesar G.; Luna H., Juan M.; Mendoza-Santoyo, Fernando

    2016-11-01

    Micro-metallic particles embedded in polymers are now widely used in several industrial applications in order to modify the mechanical properties of the bulk. A uniform distribution of these particles inside the polymers is highly desired for instance, when a biological backscattering is simulated or a bio-framework is designed. A 3D Fourier domain optical coherence tomography system to detect the polymer's internal homogeneity is proposed. This optical system has a 2D camera sensor array that records a fringe pattern used to reconstruct with a single shot the tomographic image of the sample. The system gathers the full 3D tomographic and optical phase information during a controlled deformation by means of a motion linear stage. This stage avoids the use of expensive tilting stages, which in addition are commonly controlled by piezo drivers. As proof of principle, a series of different deformations were proposed to detect the uniform or non-uniform internal deposition of copper micro particles. The results are presented as images coming from the 3D tomographic micro reconstruction of the samples, and the 3D optical phase information that identifies the in-homogeneity regions within the Poly methyl methacrylate (PMMA) volume.

  5. Morphology and damping behavior of polyurethane/PMMA simultaneous interpenetrating networks

    Directory of Open Access Journals (Sweden)

    Wang S.H.

    2001-01-01

    Full Text Available A series of polyurethane/PMMA simultaneous interpenetrating networks (SINs with various hard segment contents (X in the polyurethane phase (X = 15.5 to 36.5% in polyurethane and wide range of polyurethane (PU to polyacrylate (PA ratio (PU/PA = 20:80 to 80:20 were prepared, and the damping and mechanical properties of these materials were studied. The damping of polyurethane soft phase was increased and shifted to lower temperature with increased content of PA vitreous phase. The mechanical properties were improved with increasing PA contents. The results show that PA and the polyurethane hard segment interaction play a special role in chain interpenetration density and its magnitude is revealed by the decreased dispersed domain size observed by scanning electron microscopy (SEM and increased loss area as measured by dynamic mechanical thermal analysis (DMTA. When the weight ratio of PU/PA was 40:60, the resulting SIN materials possessed better damping properties, independent of X concentration.

  6. Creation of 3D microsculptures in PMMA by multiple angle proton irradiation

    Science.gov (United States)

    Andrea, T.; Rothermel, M.; Reinert, T.; Koal, T.; Butz, T.

    2011-10-01

    In recent years the technique of proton beam writing has established itself as a versatile method for the creation of microstructures in resist materials. While these structures can be almost arbitrary in two dimensions, the creation of genuine 3D structures remains a challenge. At the LIPSION accelerator facility a new approach has been developed which combines aspects of ion beam tomography, so far solely an analysis method, with proton beam writing. Key element is the targeted irradiation from multiple angles in order to obtain a much broader range of 3D microstructures than has hitherto been possible. PMMA columns with a diameter of ∼90 μm were used as raw material and placed in an upright position on top of a rotational axis. Using 2.25 MeV protons patterns corresponding to the silhouettes of the desired structures were written from two or more directions. In a subsequent step of chemical etching irradiated portions were dissolved, leaving behind the finished 3D sculpture. Various objects have been created. For the demonstration of the method a 70 μm high model of the Eiffel tower has been sculpted by irradiation from two angles. Using irradiation from three angles a 40 μm wide screw with right-handed thread could be crafted which might find applications in micromachining. Also, a cage structure with a pore size of ca. 20 μm was written with the intention to use it as a scaffold for the growth of biological cells.

  7. Extinguishment of a Diffusion Flame Over a PMMA Cylinder by Depressurization in Reduced-Gravity

    Science.gov (United States)

    Goldmeer, Jeffrey Scott

    1996-01-01

    Extinction of a diffusion flame burning over horizontal PMMA (Polymethyl methacrylate) cylinders in low-gravity was examined experimentally and via numerical simulations. Low-gravity conditions were obtained using the NASA Lewis Research Center's reduced-gravity aircraft. The effects of velocity and pressure on the visible flame were examined. The flammability of the burning solid was examined as a function of pressure and the solid-phase centerline temperature. As the solid temperature increased, the extinction pressure decreased, and with a centerline temperature of 525 K, the flame was sustained to 0.1 atmospheres before extinguishing. The numerical simulation iteratively coupled a two-dimensional quasi-steady, gas-phase model with a transient solid-phase model which included conductive heat transfer and surface regression. This model employed an energy balance at the gas/solid interface that included the energy conducted by the gas-phase to the gas/solid interface, Arrhenius pyrolysis kinetics, surface radiation, and the energy conducted into the solid. The ratio of the solid and gas-phase conductive fluxes Phi was a boundary condition for the gas-phase model at the solid-surface. Initial simulations modeled conditions similar to the low-gravity experiments and predicted low-pressure extinction limits consistent with the experimental limits. Other simulations examined the effects of velocity, depressurization rate and Phi on extinction.

  8. Supercritical Carbon Dioxide Assisted Processing of Silica/PMMA Nanocomposite Foams

    Science.gov (United States)

    Rende, Deniz; Schadler, Linda S.; Ozisik, Rahmi

    2012-02-01

    Polymer nanocomposite foams receive considerable attention in both scientific and industrial communities. These structures are defined as closed or open cells (pores) surrounded by bulk material and are widely observed in nature in the form of bone structure, sponge, corals and natural cork. Inspired by these materials, polymer nanocomposite foams are widely used in advanced applications, such as bone scaffolds, food packaging and transportation materials due to their lightweight and enhanced mechanical, thermal, and electrical properties compared to bulk polymer foams. The presence of the nanosized fillers facilitates heterogeneous bubble nucleation as a result, the number of bubbles increases while the average bubble size decreases. Therefore, the foam morphology can be controlled by the size, concentration, and surface chemistry of the nanofiller. In the current study, we used supercritical carbon dioxide as a foaming agent for silica/poly(methyl methacrylate), PMMA, foams. The silica nanoparticles were chemically modified by fluoroalkane chains to make them CO2-philic. The surface coverage was controlled via tethering density, and the effect of silica surface coverage and concentration on foam morphology was investigated through scanning electron microscopy and image processing. Results indicated that nanofiller concentration and filler surface chemistry (CO2-philicity) had tremendous effect on foam morphology but surface coverage did not have any effect.

  9. Miniaturized flow system based on enzyme modified PMMA microreactor for amperometric determination of glucose.

    Science.gov (United States)

    Cerdeira Ferreira, Luís Marcos; da Costa, Eric Tavares; do Lago, Claudimir Lucio; Angnes, Lúcio

    2013-09-15

    This paper describes the development of a microfluidic system having as main component an enzymatic reactor constituted by a microchannel assembled in poly(methyl methacrylate) (PMMA) substrate connected to an amperometric detector. A CO2 laser engraving machine was used to make the channels, which in sequence were thermally sealed. The internal surfaces of the microchannels were chemically modified with polyethyleneimine (PEI), which showed good effectiveness for the immobilization of the glucose oxidase enzyme using glutaraldehyde as crosslinking agent, producing a very effective microreactor for the detection of glucose. The hydrogen peroxide generated by the enzymatic reaction was detected in an electrochemical flow cell localized outside of the reactor using a platinum disk as the working electrode. The proposed system was applied to the differential amperometric determination of glucose content in soft drinks showing good repeatability (DPR=1.72%, n=50), low detection limit (1.40×10(-6)molL(-1)), high sampling frequency (calculated as 345 samples h(-1)), and relatively good stability for long-term use. The results were in close agreement with those obtained by the classical spectrophotometric method utilized to quantify glucose in biological fluids.

  10. Combination photo and electron beam lithography with polymethyl methacrylate (PMMA) resist.

    Science.gov (United States)

    Carbaugh, Daniel J; Pandya, Sneha G; Wright, Jason T; Kaya, Savas; Rahman, Faiz

    2017-09-12

    We describe techniques for performing photolithography and electron beam lithography in succession on the same resist-covered substrate. Larger openings are defined in the resist film through photolithography whereas smaller openings are defined through conventional electron beam lithography. The two processes are carried out one after the other and without an intermediate wet development step. At the conclusion of the two exposures, the resist film is developed once to reveal both large and small openings. Interestingly, these techniques are applicable to both positive and negative tone lithographies with both optical and electron beam exposure. Polymethyl methacrylate (PMMA), by itself or mixed with a photocatalytic cross-linking agent, is used for this purpose. We demonstrate that such resists are sensitive to both ultraviolet (UV) and electron beam irradiation. All four possible combinations, consisting of optical and electron beam lithographies, carried out in positive and negative tone modes have been described. Demonstration grating structures have been shown and process conditions have been described for all four cases. © 2017 IOP Publishing Ltd.

  11. Relationships between nanostructure and dynamic-mechanical properties of epoxy network containing PMMA-modified silsesquioxane

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available A new class of organic-inorganic hybrid nanocomposites was obtained by blending PMMA-modified silsesquioxane hybrid materials with epoxy matrix followed by curing with methyl tetrahydrophthalic anhydride. The hybrid materials were obtained by sol-gel method through the hydrolysis and polycondensation of the silicon species of the hybrid precursor, 3-methacryloxypropyltrimethoxysilane (MPTS, simultaneously to the polymerization of the methacrylate (MMA groups covalently bonded to the silicon atoms. The nanostructure of these materials was investigated by small angle X-ray scattering (SAXS and correlated to their dynamic mechanical properties. The SAXS results revealed a hierarchical nanostructure consisting on two structural levels. The first level is related to the siloxane nanoparticles spatially correlated in the epoxy matrix, forming larger hybrid secondary aggregates. The dispersion of siloxane nanoparticles in epoxy matrix was favored by increasing the MMA content in the hybrid material. The presence of small amount of hybrid material affected significantly the dynamic mechanical properties of the epoxy networks.

  12. Reinforcement of denture base PMMA with ZrO(2) nanotubes.

    Science.gov (United States)

    Yu, Wei; Wang, Xixin; Tang, Qingguo; Guo, Mei; Zhao, Jianling

    2014-04-01

    In the research described, ZrO2 nanotubes were prepared by anodization. The morphologies, crystal structure, etc. were characterised by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), and Fourier transform infrared spectroscopy (FTIR). ZrO2 nanotubes were pre-stirred with the denture base PMMA powder by a mechanical blender and mixed with MMA liquid to fabricate reinforced composites. The composites were tested by an electromechanical universal testing machine to study the influences of contents and surface-treatment effect on the reinforcement. The ZrO2 nanoparticles were also investigated for comparative purposes. Results indicated that ZrO2 nanotubes had a better reinforcement effect than ZrO2 nanoparticles, and surface-treatment would lower the reinforcement effect of the ZrO2 nanotubes which itself was significantly different from that of the ZrO2 nanoparticles. The flexural strength of the composite was maximised when 2.0wt% untreated ZrO2 nanotubes were added.

  13. Monitoring excimer formation of perylene dye molecules within PMMA-based nanofiber via FLIM method

    Science.gov (United States)

    Inci, Mehmet Naci; Acikgoz, Sabriye; Demir, Mustafa Muamer

    2016-04-01

    Confocal fluorescence lifetime imaging microscopy method is used to obtain individual fluorescence intensity and lifetime values of aromatic Perylene dye molecules encapsulated into PMMA based nanofibers. Fluorescence spectrum of aromatic hydrocarbon dye molecules, like perylene, depends on the concentration of dye molecules and these dye molecules display an excimeric emission band besides monomeric emission bands. Due to the dimension of a nanofiber is comparable to the monomer emission wavelength, the presence of nanofibers does not become effective on the decay rates of a single perylene molecule and its lifetime remains unchanged. When the concentration of perylene increases, molecular motion of the perylene molecule is restricted within nanofibers so that excimer emission arises from the partially overlapped conformation. As compared to free excimer emission of perylene, time-resolved experiments show that the fluorescence lifetime of excimer emission of perylene, which is encapsulated into NFs, gets shortened dramatically. Such a decrease in the lifetime is measured to be almost 50 percent, which indicates that the excimer emission of perylene molecules is more sensitive to change in the surrounding environment due to its longer wavelength. Fluorescence lifetime measurements are typically used to confirm the presence of excimers and to construct an excimer formation map of these dye molecules.

  14. Experimental and theoretical analysis of defocused CO2 laser microchanneling on PMMA for enhanced surface finish

    Science.gov (United States)

    Prakash, Shashi; Kumar, Subrata

    2017-02-01

    The poor surface finish of CO2 laser-micromachined microchannel walls is a major limitation of its utilization despite several key advantages, like low fabrication cost and low time consumption. Defocused CO2 laser beam machining is an effective solution for fabricating smooth microchannel walls on polymer and glass substrates. In this research work, the CO2 laser microchanneling process on PMMA has been analyzed at different beam defocus positions. Defocused processing has been investigated both theoretically and experimentally, and the depth of focus and beam diameter have been determined experimentally. The effect of beam defocusing on the microchannel width, depth, surface roughness, heat affected zone and microchannel profile were examined. A previously developed analytical model for microchannel depth prediction has been improved by incorporating the threshold energy density factor. A semi-analytical model for predicting the microchannel width at different defocus positions has been developed. A semi-empirical model has also been developed for predicting microchannel widths at different defocusing conditions for lower depth values. The developed models were compared and verified by performing actual experiments. Multi-objective optimization was performed to select the best optimum set of input parameters for achieving the desired surface roughness.

  15. Nanocomposites of poly(methyl methacrylate (PMMA and montmorillonite (MMT Brazilian clay: A tribological study

    Directory of Open Access Journals (Sweden)

    2010-09-01

    Full Text Available Nanocomposites of PMMA+MMT Brazilian clays were developed by mechanical mixing in co-rotational twinscrew extrusion and injection molding with varying weight fraction of MMT Brazilian clays. The clays were purchased in crude form and then washed and purified to extract the organic materials and contaminants. Dynamic friction and wear rate of these composites were studied as a function of concentration of the Brazilian clay. With an increase in the amount of MMT Brazilian clay, the dynamic friction of the nanocomposites increases, a clear but not large effect. It can be explained by sticky nature of clay; clay in the composite is also on the surface and sticks to the partner surface. The wear rate as a function of the clay concentration passes through a minimum at 1 wt% MMT; at this concentration the clay provides a reinforcement against abrasion. At higher clay concentrations we see a dramatic increase in wear – a consequence of clay agglomeration and increased brittleness. The conclusions are confirmed by microscopy results.

  16. Microstructure and Electrical Conductivity of CNTs/PMMA Nanocomposite Foams Foaming by Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    YUAN Huan; XIONG Yuanlu; LUO Guoqiang; LI Meijuan; SHEN Qiang; ZHANG Lianmeng

    2016-01-01

    The carbon nanotubes (CNTs)/ polymethylmethacrylate (PMMA) nanocomposite foams were prepared by the anti-solvent precipitation and supercritical foaming method. The morphology and the electrical conductivity of the foams with different kinds of CNTs were investigated. The experimental results showed that all the foams had uniform cell structure, and the cell size changed from 1.9 to 10 μm when the foaming temperature ranged from 50℃ to 95℃. With small cell size (1.9-4.0 μm), the conductivities of the foams were 3.34×10-6-4.16×10-6 S/cm compared with the solid matrix since the introduction of micro cells did not destroy the conductive network. However, when the cell size was biger (4.5-10 μm), the aspect ratio of the CNTs played the dominant role of the conductivity. The foams with short CNTs had higher conductivity, since the short CNTs were hard to stretch and snap by the cells and can well-dispersed in the cell wall and cell edges. The results of this work provided a novel material design method for conductive foams based on the rule of both microstructure and aspect ratio of the CNTs.

  17. Physical aging of glassy PMMA/toluene films: influence of drying/swelling history.

    Science.gov (United States)

    Doumenc, F; Bodiguel, H; Guerrier, B

    2008-09-01

    Gravimetry experiments in a well-controlled environment have been performed to investigate aging for a glassy PMMA/toluene film. The temperature is constant and the control parameter is the solvent vapor pressure above the film (i.e. the activity). Several experimental protocols have been used, starting from a high activity where the film is swollen and rubbery and then aging the film at different activities below the glass transition. Desorption and resorption curves have been compared for the different protocols, in particular in terms of the softening time, i.e. the time needed by the sample to recover an equilibrium state at high activity. Non-trivial behaviors have been observed, especially at small activities (deep quench). A model is proposed, extending the Leibler-Sekimoto approach to take into account the structural relaxation in the glassy state, using the Tool formalism. This model well captures some of the observed phenomena, but fails in describing the specific kinetics observed when aging is followed by a short but deep quench.

  18. Ultrasound assisted synthesis of PMMA/clay nanocomposites: Study of oxygen permeation and flame retardant properties

    Indian Academy of Sciences (India)

    Subrata K Patra; Gyanaranjan Prusty; Sarat K Swain

    2012-02-01

    PMMA/clay nanocomposites were synthesized by ultrasound assisted emulsifier-free emulsion polymerization technique. Ultrasound waves of different power and frequencies were applied to enhance the dispersion of the clay layers with polymer matrix. The structural information of the synthesized materials was studied by X-ray diffraction (XRD) and it was revealed that the interlayer spacing increased with clay loading. The magnitude of dispersion of the clay in the polymer matrix was detected by transmission electron microscopy (TEM). The Young’s modulus, breaking stress, elongation at break, toughness, yield stress and yield strain of the nanocomposites as a function of different clay concentrations and ultrasonic power were measured. Particle diameter of the nanocomposites was measured by laser diffraction technique. Oxygen permeability of the samples was studied and it was found that the oxygen flow rate was reduced by the combined effect of clay loading and ultrasound. The flame retardant property of the nanocomposites due to clay dispersion was investigated by measurement of limiting oxygen index (LOI).

  19. Wide spectral and wavelength-tunable dissipative soliton fiber laser with topological insulator nano-sheets self-assembly films sandwiched by PMMA polymer.

    Science.gov (United States)

    Wang, Qingkai; Chen, Yu; Miao, Lili; Jiang, Guobao; Chen, Shuqing; Liu, Jun; Fu, Xiquan; Zhao, Chujun; Zhang, Han

    2015-03-23

    Topological insulators have been theoretically predicted as promising candidates for broadband photonics devices due to its large bulk band gap states in association with the spin-momentum-locked mass-less Dirac edge/surface states. Unlike the bulk counterpart, few-layer topological insulators possess some intrinsic optical advantages, such as low optical loss, low saturation intensity and high concentration of surface state. Herein, we use a solvothermal method to prepare few-layer Bi₂Te₃ flakes. By sandwiching few-layer Bi₂Te₃ flakes with polymethyl methacrylate (PMMA) polymer, a novel light modulation device had been successfully fabricated with high chemical and thermal stabilities as well as excellent mechanical durability, originating from the contribution of PMMA acting as buffer layers that counteract excessive mechanical bending within the fragile Bi₂Te₃ flakes. The incorporation of the as-fabricated PMMA-TI-PMMA as saturable absorber, which could bear long-term mechanical loadings, into the fiber laser cavity generated the stable dissipative soliton mode-locking with a 3-dB spectral bandwidth up to 51.62 nm and tunable wavelength range of 22 nm. Our work provides a new way of fabricating PMMA-TI-PMMA sandwiched composite structure as saturable absorber with promising applications for laser operation.

  20. Low-temperature Preparation of Photocatalytic TiO2 Thin Films on Polymer Substrates by Direct Deposition from Anatase Sol

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Anatase TiO2 sol was synthesized under mild conditions (75C and ambient pressure) by hydrolysis of titaniumn-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. At room temperature and in ambient atmosphere, crystalline TiO2 thin films were deposited on polymethylmethacrylate (PMMA), SiO2-coated PMMA and SiO2-coated silicone rubber substrates from the as-prepared TiO2 sol by a dip-coating process. SiO2 layers prior to TiO2 thin films on polymer substrates could not only protect the substrates from the photocatalytic decomposition of the TiO2 thin films but also enhance the adhesion of the TiO2 thin films to the substrates. Field-emission type scanning electron microscope (FE-SEM) investigations revealed that the average particle sizes of the nanoparticles composing the TiO2 thin films were about 35~47 nm. The TiO2 thin films exhibited high photocatalytic activities in the degradation of reactive brilliant red dye X-3B in aqueous solution under aerated conditions. The preparation process of photocatalytic TiO2 thin films on the polymer substrates was quite simple and a low temperature route.

  1. Safety and feasibility of percutaneous vertebroplasty with radioactive {sup 153}Sm PMMA in an animal model

    Energy Technology Data Exchange (ETDEWEB)

    Lu Jun [Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China); Deng Jinglan, E-mail: dengjinglan@gmail.com [Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China); Zhao Haitao [Department of Radiology, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China); Shi Mei [Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China); Wang Jing [Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China); Zhao Lina [Department of Radiotherapy, Xijing Hospital, Fourth Military Medical University, 15 West Changle Road, Xi' an 710032, Shaanxi Province (China)

    2011-05-15

    Purpose: We investigated the safety and feasibility of the combination of samarium-153-ethylenediamine tetramethylene phosphonate ({sup 153}Sm-EDTMP)-incorporated bone cement (BC) with percutaneous vertebroplasty (PVP) in dogs. Methods and materials: {sup 153}Sm-EDTMP-incorporated BC was prepared by combining solid {sup 153}Sm-EDTMP and polymethylmethacrylate (PMMA) immediately before PVP. It was then injected into the vertebrae of four healthy mongrel dogs (two males and two females) by PVP under CT guidance. Each dog was subjected to five PVP sessions at a {sup 153}Sm-EDTMP dose of 30-70 mCi. The suppressive effect of local injection of {sup 153}Sm-EDTMP on the hematopoietic system was evaluated through counting of peripheral blood cells. Distribution of {sup 153}Sm-EDTMP-incorporated BC and the status of tissues adjacent to injected vertebrae were evaluated with SPECT, CT and MRI. Histopathology was carried out to assess the influence of PVP on the vertebra and adjacent tissues at the microscopic level. Results: PVP was done successfully, and all dogs exhibited normal behavior and stable physical signs after procedures. {sup 153}Sm-EDTMP-incorporated BC was concentrated mainly in target vertebrae, and the peripheral blood cells remained within normal range. The spinal cord and tissues around BC did not exhibit signs of injury even when the dosage of {sup 153}Sm-EDTMP increased from 30 mCi to 70 mCi. Conclusion: A dose lower than 70 mCi of {sup 153}Sm is safe when it was injected into vertebrae. {sup 153}Sm-EDTMP-incorporated BC did not influence the effect of PVP. This means might strengthen anti-tumor activity locally for vertebra with osseous metastasis without damaging adjacent tissues.

  2. The local segmental dynamics of polymer thin films

    Science.gov (United States)

    Roland, C. M.; Casalini, Riccardo; Prevosto, Daniele; Labardi, Massimiliano; Zhu, Lei; Baer, Eric

    The local segmental dynamics of poly(methyl methacrylate) (PMMA) in multi-layered films with polycarbonate was investigated using dielectric spectroscopy. The segmental relaxation time decreased with layer thickness down to 4 nm. However, two measures of the cooperativity of the dynamics, the breadth of the relaxation dispersion and the dynamic correlation volume, were unaffected by the film thickness. This absence of an effect of geometric confinement on the cooperativity, even when the confinement length scale approaches the correlation length scale, requires an asymmetric correlation volume; i.e., correlating regions having a string-like nature. To further probe the effect of layering on the segmental dynamics, we measured the segmental dynamics of poly(vinylacetate) thin films in contact with variously an aluminum interface, an incompatible polymer, and air (free surface). From local dielectric relaxation measurements using an AFM tip, the dynamics were observed to be faster in all thin film configurations compared to the bulk. However, no differences were observed for the various interfaces; capping the thin films with a rigid material accelerated the segmental motions equivalently to that for an air interface. This insensitivity of the dynamics to the nature of the interface affords a means to engineer thin films while maintaining desired mechanical properties. Work at NRL supported by the Office of Naval Research.

  3. Processing influence on the morphology of PVDF/PMMA blends examined by scanning electron microscopy; Influencia do processamento na morfologia de misturas PVDF/PMMA examinada por microscopia eletronica de varredura

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Estevao, E-mail: estevao@eq.ufrj.br [Dept. de Processos Organicos, Escola de Quimica, Universidade Federal do Rio de Janeiro, RJ (Brazil); Forte, Maria M.C. [Programa de Pos Graduacao em Engenharia de Minas, Metalurgica e de Materiais, Escola de Engenharia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Monteiro, Elisabeth E.C. [Instituto de Macromoleculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2011-07-01

    PVDF/PMMA blends were melt blended in proportions of 20, 40 e 60% PVDF by weight in two different mixers, a low shear and a high shear mixer. The compositions obtained were examined by scanning electron microscopy. The results were correlated with the two types of processing and showed that the type of mixer affects the morphology of the blend. The morphologies obtained corroborated the NMR analysis demonstrating the phase separation phenomena and the effect of the type of mixer used in this study. (author)

  4. Holographic Grating Formation in Photochromic Diarylethene-Doped Polymeric Thin Films

    Institute of Scientific and Technical Information of China (English)

    LUO Shou-Jun; LIU Guo-Dong; HE Qing-Sheng; JIN Guo-Fan

    2005-01-01

    We introduce a modeJ to describe real-time grating formation in holographic photochromic diarylethene-dopedpolymeric thin films. This model, which combines photochromic chemical reaction with the coupled-wave theory, indicates that the grating recording time depends on the molecular absorption coefficient of molecules and the quantum yield of the photochromic reaction at a certain holographic recording intensity. The model is validated by comparing its predictions with the experimental results in which photochromic molecule 1,2-bis(2-methyl-5-(4-formylphenyl)-3-thienyl) perfluorocyclopentene doped PMMA films were used.

  5. Electrical characteristics of top contact pentacene organic thin film transistors with SiO2 and poly(methyl methacrylate) as gate dielectrics

    Indian Academy of Sciences (India)

    Jaya Lohani; Praveen Saho; Upender Kumar; V R Balakrishnan; P K Basu

    2008-09-01

    Organic thin film transistors (OTFTs) were fabricated using pentacene as the active layer with two different gate dielectrics, namely SiO2 and poly(methyl methacrylate) (PMMA), in top contact geometry for comparative studies. OTFTs with SiO2 as dielectric and gold deposited on the rough side of highly doped silicon (n+ -Si) as gate electrode exhibited reasonable field effect mobilities. To deal with poor stability and large leakage currents between source/drain and gate electrodes in these devices, isolated OTFTs with reduced source/drain contact area were fabricated by selective deposition of pentacene on SiO2/PMMA through shadow mask. This led to almost negligible leakage currents and no degradation in electrical performance even after 14 days of storage under ambient conditions. But, the field effect mobilities obtained were lower than 10-3 cm2 V-1 s-1, whereas by using PMMA as gate dielectric with chromium deposited on the polished side of n+ -Si as gate electrode, improved field effect mobilities (> 0.02 cm2 V-1 s-1) were obtained. PMMA-based OTFTs also exhibited lower leakage currents and reproducible output characteristics even after 30 days of storage under ambient conditions.

  6. Fatty acid/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet [Gaziosmanpasa University, Department of Chemistry, Tasliciftlik, 60240 Tokat (Turkey)

    2008-02-15

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA), and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the most drawback which limits the utility area of them in thermal energy storage. The use of fatty acids as form-stable PCM will increase their feasibilities in practical LHTES applications due to reduced cost of the energy storage system. In this regard, a series of fatty acid/poly(methyl methacrylate) (PMMA) blends, SA/PMMA, PA/PMMA, MA/PMMA, and LA/PMMA were prepared as new kinds of form-stable PCMs by encapsulation of fatty acids into PMMA which acts as supporting material. The blends were prepared at different mass fractions of fatty acids (50, 60, 70, 80, and 90% w/w) to reach maximum encapsulation ratio. All blends were subjected to leakage test by heating the blends over the melting temperature of the PCM. The blends that do not allow leakage of melted PCM were identified as form-stable PCMs. The form-stable fatty acid/PMMA (80/20 wt.%) blends were characterized using optic microscopy (OM), viscosimetry, and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the PMMA was compatible with the fatty acids. In addition, thermal characteristics such as melting and freezing temperatures and latent heats of the form-stable PCMs were measured by using differential scanning calorimetry (DSC) technique and indicated that they had good thermal properties. On the basis of all results, it was concluded that form-stable fatty acid/PMMA blends had important potential for some practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floor impregnated with a form-stable PCM due to their satisfying thermal properties, easily preparing in desired dimensions, direct usability without needing an add encapsulation and

  7. Influence of ZrO{sub 2} nanoparticles and thermal treatment on the properties of PMMA/ZrO{sub 2} hybrid coatings

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Acosta, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, CIAMS (Mexico); Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Torres-Huerta, A.M., E-mail: atorresh@ipn.mx [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Domínguez-Crespo, M.A. [Instituto Politécnico Nacional, CICATA-Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, C.P. 89600 Altamira, Tamps. (Mexico); Flores-Vela, A.I. [Instituto Politécnico Nacional, CMP+L, Av. Acueducto s/n, Barrio La Laguna, Col. Ticomán, C.P. 07340 México D.F. (Mexico); Dorantes-Rosales, H.J. [Instituto Politécnico Nacional, SEPI-ESIQIE, Departamento de Metalurgia, C.P. 07738 México D.F. (Mexico); Ramírez-Meneses, E. [Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, Distrito Federal C.P. 01219 (Mexico)

    2015-09-15

    Highlights: • PMMA/ZrO{sub 2} nanocomposites were prepared by melt blending in a single screw extruder. • The nanoparticles of m-, t-ZrO{sub 2} were successfully synthesized using sol–gel technique. • The prepared PMMA/ZrO{sub 2} nanocomposites have better UV protection than pure PMMA. • The thermal stability of the PMMA increases with low amount of ZrO{sub 2} nanoparticles. • PMMA/ZrO{sub 2} nanocomposites show superior values of elastic modulus and hardness. - Abstract: In this work, ZrO{sub 2} nanoparticles were synthesized by the sol–gel method, treated thermally at different temperatures (400, 600 and 800 °C), and added to a polymer matrix in two different weight percentages (0.5 and 1) by single screw extrusion in order to determine the influence of these parameters on the thermal stability and UV radiation resistance of PMMA/ZrO{sub 2} composites. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), X-ray diffraction (XRD), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM), ultraviolet–visible spectroscopy (UV–Vis), thermogravimetric analysis (TGA) and nanoindentation techniques were used to evaluate the structural, morphological, optical, thermal and mechanical properties of as-prepared composites. The average crystallite sizes for ZrO{sub 2} sintered at 600 and 800 °C were about 17 and 26 nm, respectively. It was found that the incorporation of a low percentage of ZrO{sub 2} nanoparticles increased the thermal properties of PMMA as well as its hardness and elastic modulus. The degradation temperature at 10 wt.% loss of the PMMA/ZrO{sub 2} (0.5 wt.%, 400 °C) nanocomposite was approximately 48 °C higher than that of pure PMMA. The absorption in the UV region was increased according to the ZrO{sub 2} heat treatment temperature and amount added to the polymer matrix.

  8. A facile approach for cupric ion detection in aqueous media using polyethyleneimine/PMMA core-shell fluorescent nanoparticles

    Science.gov (United States)

    Chen, Jian; Zeng, Fang; Wu, Shuizhu; Su, Junhua; Zhao, Jianqing; Tong, Zhen

    2009-09-01

    A facile approach was developed to produce a dye-doped core-shell nanoparticle chemosensor for detecting Cu2+ in aqueous media. The core-shell nanoparticle sensor was prepared by a one-step emulsifier-free polymerization, followed by the doping of the fluorescent dye Nile red (9-diethylamino- 5H-benzo[alpha] phenoxazine-5-one, NR) into the particles. For the nanoparticles, the hydrophilic polyethyleneimine (PEI) chain segments serve as the shell and the hydrophobic polymethyl methacrylate (PMMA) constitutes the core of the nanoparticles. The non-toxic and biocompatible PEI chain segments on the nanoparticle surface exhibit a high affinity for Cu2+ ions in aqueous media, and the quenching of the NR fluorescence is observed upon binding of Cu2+ ions. This makes the core-shell nanoparticle system a water-dispersible chemosensor for Cu2+ ion detection. The quenching of fluorescence arises through intraparticle energy transfer (FRET) from the dye in the hydrophobic PMMA core to the Cu2+/PEI complexes on the nanoparticle surface. The energy transfer efficiency for PEI/PMMA particles with different diameters was determined, and it is found that the smaller nanoparticle sample exhibits higher quenching efficiency, and the limit for Cu2+ detection is 1 µM for a nanoparticle sample with a diameter of ~30 nm. The response of the fluorescent nanoparticle towards different metal ions was investigated and the nanoparticle chemosensor displays high selectivity and antidisturbance for the Cu2+ ion among the metal ions examined (Na+, K+, Mg2+, Ca2+, Zn2+, Hg2+, Mn2+, Fe2+, Ni2+, Co2+ and Pb2+). This emulsifier-free, biocompatible and sensitive fluorescent nanoparticle sensor may find applications in cupric ion detection in the biological and environmental areas.

  9. Determination of the linear coefficient of thermal expansion in polymer films at the nanoscale: influence of the composition of EVA copolymers and the molecular weight of PMMA.

    Science.gov (United States)

    González-Benito, J; Castillo, E; Cruz-Caldito, J F

    2015-07-28

    Nanothermal-expansion of poly(ethylene-co-vinylacetate), EVA, and poly(methyl methacrylate), PMMA, in the form of films was measured to finally obtain linear coefficients of thermal expansion, CTEs. The simple deflection of a cantilever in an atomic force microscope, AFM, was used to monitor thermal expansions at the nanoscale. The influences of: (a) the structure of EVA in terms of its composition (vinylacetate content) and (b) the size of PMMA chains in terms of the molecular weight were studied. To carry out this, several polymer samples were used, EVA copolymers with different weight percents of the vinylacetate comonomer (12, 18, 25 and 40%) and PMMA polymers with different weight average molecular weights (33.9, 64.8, 75.600 and 360.0 kg mol(-1)). The dependencies of the vinyl acetate weight fraction of EVA and the molecular weight of PMMA on their corresponding CTEs were analyzed to finally explain them using new, intuitive and very simple models based on the rule of mixtures. In the case of EVA copolymers a simple equation considering the weighted contributions of each comonomer was enough to estimate the final CTE above the glass transition temperature. On the other hand, when the molecular weight dependence is considered the free volume concept was used as novelty. The expansion of PMMA, at least at the nanoscale, was well and easily described by the sum of the weighted contributions of the occupied and free volumes, respectively.

  10. Sensitization and Intra-molecular Energy Transfer of Eu3+ by Tb3+ in Eu-Tb Binuclear Complexes/PMMA

    Institute of Scientific and Technical Information of China (English)

    HAN Jing; LI Jie

    2011-01-01

    A series of Eu0.5Tb0.5(TTA)3Phen/PMMA (TTA=thenoyltrifluoroacetone, Phen=phenanthroline)and Eu0.5Tb0.5(TTA)3Dipy/PMMA (Dipy=2,2'-dipyridyl) were prepared by in-situ polymerization. The structures of the composites were characterized by IR spectra and electron spectrum. Photoluminescence properties were investigated by UV-Vis spectra and fluorescence spectra. Meanwhile, the energy transfer models were set up.The results indicated that polymer parts were attached with the rare-earth molecular parts in the composite luminescent materials. Eu0.5Tb0.5(TTA)3Phen/PMMA and Eu0.5Tb0.5(TTA)3Dipy/PMMA emitted mostly characteristic fluorescence of europium ion and intense red fluorescence with peak wavelength at 611.8 nm and bandwidth of 10.4 nm under UV excitation at 365 nm. Fluorescence intensity of Eu0.5Tb0.5(TTA)3Phen/PMMA was found to be influenced with the content of MMA. The fluorescence emission of europium ions was greatly sensitized by terbium ions and the enhancement of red emission was most likely due to the energy transfer enhancement from Th3+ to Eu3+.

  11. Simultaneous enhancement in mechanical strength, electrical conductivity, and electromagnetic shielding properties in PVDF-ABS blends containing PMMA wrapped multiwall carbon nanotubes.

    Science.gov (United States)

    Kar, Goutam Prasanna; Biswas, Sourav; Bose, Suryasarathi

    2015-06-14

    A unique approach was adopted to drive the multiwall carbon nanotubes (MWNTs) to the interface of immiscible PVDF-ABS blends by wrapping the nanotubes with a mutually miscible homopolymer (PMMA). A tailor made interface with an improved stress transfer was achieved in the blends with PMMA wrapped MWNTs. This manifested in an impressive 108% increment in the tensile strength and 48% increment in the Young's modulus with 3 wt% PMMA wrapped MWNTs in striking contrast to the neat blends. As the PMMA wrapped MWNTs localized at the interface of PVDF-ABS blends, the electrical conductivity could be tuned with respect to only MWNTs, which were selectively localized in the PVDF phase, driven by thermodynamics. The electromagnetic shielding properties were assessed using a vector network analyser in a broad range of frequency, X-band (8-12 GHz) and Ku-band (12-18 GHz). Interestingly, enhanced EM shielding was achieved by this unique approach. The blends with only MWNTs shielded the EM waves mostly by reflection however, the blends with PMMA wrapped MWNTs (3 wt%) shielded mostly by absorption (62%). This study opens new avenues in designing materials, which show simultaneous improvement in mechanical, electrical conductivity and EM shielding properties.

  12. Experience with polymethylmethacrylate 30% (PMMA facial filling in patients with facial HIV lipoatrophy using of local anesthesia dentistry

    Directory of Open Access Journals (Sweden)

    E Matsuda

    2012-11-01

    Full Text Available Background HIV-associated lipoatrophy in a common and stigmatizing side effect of HIV infection, is aggravated by antiretroviral therapy; its presence causes distress and compromises adherence to therapy. PMMA filling is often associated with pain and discomfort. Objective To evaluate outpatient intervention using local dentistry anesthesia. Methods Patients complaining of facial lipoatrophy, from 10/2007 to 11/2011, were offered the filling with PMMA. Cases with bleeding potential, acute or decompensated chronic diseases or use of immunosuppressors or chemotherapy were excluded. Inclusion criteria: perception of distressing malar lipoatrophy and both the assisting physician and the applicant agreeing with potential benefit. After informed consent, patients were infused with 30 mg prilocaine/0.03 IU felypressin in 1.8 ml, using a carpule type syringe aiming to block the posterior superior alveolar nerve. This was followed by PMMA infiltration in different points at the malar region. At first return a simple questionnaire evaluating pain, satisfaction, grading 0 to 10 and if would repeat the procedure. Results All 64 eligible patients were included. Mean age 46 (13 to 73 years, mostly white (71.87%, males (68.75%, 37.5% of them MSM. Arterial hypertension was the most prevalent comorbidity (17%, 78% with viral load <50 c/mL, with a median 585 CD4 cells/mL (95–2063. On a median of 8 years on treatment, 1/3 had been exposed to three classes (NRTI/ NNRTI/PI, one antiretroviral-naïve. Of the 12 patients who had detectable viral load in the first procedure, seven were suppressed to below 50 copies/mL during follow up. Two of the five patients remaining with detectable viremia died from other causes, 2 transferred and 1 remained naïve. 127 procedures were made in 64 patients, a median of 2 (1–6 per patient. After a mean follow-up of 33 weeks, no infection or late complications were observed. Mean dispensed volume was 9 mL (1.5 to 22. Pain grade

  13. Testing the diffusion hypothesis as a mechanism of self-healing in Disperse orange 11 doped in PMMA

    CERN Document Server

    Ramini, Shiva K; Kuzyk, Mark G

    2011-01-01

    In this work, we show that reversible photodegradation of Disperse Orange 11 doped in PMMA is not due to dye diffusion - a common phenomenon observed in many dye-doped polymers. The change in linear absorbance due to photodegradation of the material shows an isobestic point, which is consistent with the formation of a quasi-stable damaged species. Spatially-resolved amplified spontaneous emission and fluorescence, both related to the population density, are measured by scanning the pump beam over a burn mark. A numerical model of the time evolution of the population density due to diffusion is inconsistent with the experimental data suggesting that diffusion is not responsible.

  14. Preparation, Microhardness Characterization on Untreated And Treated With Electric Stressed Samples on The Inorganic Tunable Laser Dye Rhodamine Doped PMMA

    Directory of Open Access Journals (Sweden)

    Pradeep Kumar Dubey, R. Bajpai , J. M. Keller

    2013-04-01

    Full Text Available Effect of Load, Load dependent nature of Microhardness measurement and Doping Effect on untreated samples and Microhardness studies on the effect of charge due to electrical stress on the samples of pure and Rhodamine doped PMMA with different weights proportions have been carried out using Vicker’s microhardness testing for hardened networks plasticization and crystallization. Some selected samples are used to study the electrical stress, with the help of thermostat controller at different polarizing temperatures and fields in thermally stimulated depolarization current due to dipole orientation or trapping of space charges, which gives the information about uniform polarization.

  15. Effective absorption coefficient measurements in PMMA and PTFE by clean ablation process with a coherent VUV source at 125 nm

    Science.gov (United States)

    Riedel, D.; Castex, M. C.

    First measurements of effective absorption coefficient and penetration depth are given here from the ablation of poly-methylmethacrylate (PMMA) and poly-tetrafluoroethylene (PTFE) samples at 125 nm ( 10 eV). The coherent VUV source used which provides smooth, efficient and clean etched areas, is briefly described. Experimental curves of etch depth as a function of the number of laser shots and etch rate as a function of energy density are obtained and compared with previous works performed at 157 nm (F2 laser) and 193 nm (ArF laser). Experimental results are described with a Beer-Lambert absorption law and discussed.

  16. Infrared complex refractive index measurements and simulated reflection mode infrared absorption spectroscopy of shock-compressed polymer thin films.

    Science.gov (United States)

    Moore, D S; McGrane, S D; Funk, D J

    2004-05-01

    Thin film interference effects complicate the interpretation of reflection-mode infrared absorption spectra obtained in shock-compressed thin film materials and must be carefully accounted for in any analysis attempting to unravel shock-induced energy transfer or reactivity. We have calculated such effects for spectrally simple model systems and also, to the extent possible, for real systems such as polymethylmethacrylate (PMMA) and nitrocellulose (NC). We have utilized angle-dependent infrared (IR) reflectometry to obtain the ambient spectral complex index for PMMA and NC for use in the calculations and to interpret experiments. A number of counter-intuitive spectral effects are observed versus film thickness and during uniaxial shock compression: absorption band shifts, changes of shape, and changes in both absolute and relative peak intensities. The film thickness effects can be predicted by thin film interference alone, while additional assumptions are required to predict the effects due to shock compression. Since it is very difficult to obtain the complex index in the shock state, we made very simple assumptions regarding the change in vibrational spectra upon shock load-ing. We illustrate general thin film interference effects that could be expected and compare them to experimental results for the antisymmetric NO2 stretch mode of NC.

  17. Fabrications of a Poly (Methyl Methacrylate ) (PMMA) Microfluidic Chip-Based DNA Analysis Device%聚甲基丙烯酸甲酯(PMMA)微流控芯片DNA分析系统的研制

    Institute of Scientific and Technical Information of China (English)

    杜晓光

    2009-01-01

    A DNA analysis device based on poly(methyl methacrylate) (PMMA) microfluidic chips was developed. A PMMA chip with cross microchannels was fabricated by a simple hot embossing. Microchannels were modified with a static adsorptive coating method using 2% hydroxyethyl cellulose. A high-voltage power unit, variable in the range 0-1 800 V, was used for on-chip DNA sample injection and gel electrophoretic separation. High speed, high resolution DNA analysis was obtained with the home-buih PMMA chip in a sieving matrix containing 2% hydroxyethyl cellulose with a blue intercalating dye, TO-PRO-3 (TP3), by using diode laser induced fluorescence detection based on optical fibers with a 670 nm long-pass filter. The DNA analysis device was applied for the separation of ψX-174/HaeⅢ DNA digest sample with 11 fragments ranging from 72 to 1 353 hp. A separation efficiency of 1.14×10~6 plates/m was obtained for the 603 bp fragments, while the R of 271/281 hp fragments was 1.2. The device was characterized by simple design, low cost for fabrication and operation, reusable PMMA chips, and good reproducibility. A portable microfluidic device for DNA analysis can be developed for clinical diagnosis and disease screen-ing.%生物分析是微流控芯片分析最具进一步发展及商品化前景的分支领域之一.报道了基于聚甲基丙烯酸甲酯(PMMA)微流控芯片DNA分析系统的研制.采用简易热压法自制的PMMA芯片,以小型光纤式激光诱导荧光为检测器,以四触点可切换1 800 V高压电源为电驱动系统,以2%羟乙基纤维素(HEC)为筛分介质,通过用于DNA分析的TO-PRO-3荧光染料和激光诱导荧光检测器670 nm截止滤光片的选择,构建了微流控芯片DNA分析系统.芯片凝胶电泳分离ψX174-HaeⅢRF DNA片段,以603 bp片段计算理论塔板数n为1.14×10~6·m~-1,271/281 bp的分离度R为1.2.建立的PMMA微流控芯片DNA分析系统具有制作和运行成本低,芯片可重复使用,分析重现性好

  18. Effects of the novel poly(methyl methacrylate) (PMMA)-encapsulated organic ultraviolet (UV) filters on the UV absorbance and in vitro sun protection factor (SPF).

    Science.gov (United States)

    Wu, Pey-Shiuan; Huang, Lan-Ni; Guo, Yi-Cing; Lin, Chih-Chien

    2014-02-05

    Sunscreens are thought to protect skin from many of the harmful effects of ultraviolet (UV) light and the photostability of sunscreens is thus an important concern in their application. Therefore, to discover new UV filters or to modify well-known UV filters are presents an important way for development of sunscreens. In this study, we presented several novel poly(methyl methacrylate) (PMMA) encapsulated organic UV filters, including encapsulated benzophenone-3 (TB-MS), avobenzone (TA-MS), octyl methoxycinnamate (TO-MS) and diethylamino hydroxybenzoyl hexyl benzoate (TD-MS). Our results have demonstrated that PMMA-encapsulated UV filters have improved safety, photoprotective ability and photostability. We proposed therefore that these PMMA-encapsulated UV filters can be used as ingredients for sunscreen products in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Synthesis and study of thermal, mechanical and biodegradation properties of chitosan-g-PMMA with chicken egg shell (nano-CaO) as a novel bio-filler.

    Science.gov (United States)

    Pradhan, Arun K; Sahoo, Prafulla K

    2017-11-01

    The important objective of this study is to evaluate the effect of chicken eggshell (nano-Cao) as a functionalized bio-filler on the mechanical strength and thermal stability of acrylic based bionanocomposite of chitosan grafted with poly(methyl methacrylate)(PMMA). The chitosan grafted PMMA adsorbed with functionalized biofiller was prepared via emulsion polymerisation technique and physicochemically characterized as bone graft substitute. The so prepared grafted bioactive bone cement (BBC) bionanocomposite (BNC), chitosan-g-PMMA/nano-CaO was characterized by FTIR, XRD, FESEM and TGA. The water uptake, retention ability, their biodegradability and the nanosize particle arrangement in the polymeric BBC-BNCs were undertaken. These preliminary investigations of the BNCs will open the door for their use in bioadhesive bone cement implants in future. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Microsphere templating as means of enhancing surface activity and gas sensitivity of CaCu(3)Ti(4)O(12) thin films.

    Science.gov (United States)

    Kim, Il-Doo; Rothschild, Avner; Hyodo, Takeo; Tuller, Harry L

    2006-02-01

    Chemical and physical synthesis routes were combined to prepare macroporous CaCu(3)Ti(4)O(12) thin films by pulsed laser deposition onto poly(methyl methacrylate) (PMMA) microsphere templated substrates. These films showed remarkably enhanced gas sensitivity compared with control films deposited on untreated substrates, demonstrating the virtues of combining thin film physical vapor deposition (PVD) techniques in concert with colloidal templates to produce macroporous structures of inorganic films with enhanced surface activity for applications in chemical sensors, catalysts, and fuel cells.

  1. Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer

    Directory of Open Access Journals (Sweden)

    Carla N. Toledo

    2014-01-01

    Full Text Available Myoglobin was immobilized with poly(methyl methacrylate-block-poly[(2-dimethylaminoethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT. Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant (Ks and transfer coefficient (α were 0.055±0.01·s−1 and 0.81±0.08, respectively. The reduction potential determined as a function of temperature (293–328 K revealed a value of reaction center entropy of ΔS0 of 351.3±0.0002 J·mol−1·K−1 and enthalpy change of -76.8±0.1 kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of 114.7±58.7 μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors.

  2. The short-term effects of PMMA contact lens wear on keratometric behaviour: results for a single keratoconic cornea*

    Directory of Open Access Journals (Sweden)

    E. Chetty

    2010-12-01

    Full Text Available Keratometric behaviour is a multifaceted issue that many researchers have investigated for years. Many internal and external influences can have an effect on the cornea’s keratometric behaviour. This investigation forms a small part of a larger study that aims at determining the effects that rigid contact lenses might have on keratometric behaviour. This pilot study examined the keratometric behaviour of a single, mildly keratoconic cornea that was fitted with a polymethyl methacrylate (PMMA contact lens. Sixty successive auto-keratometric measurements were taken immediately before and immediately after three hours of contact lens wear. The data obtained was transformed to dioptric power matrices and were analysed using multivariate statistical methods. This study showed that, at least in one keratoconic cornea, there appeared to be a statistically significant change in corneal curvature under the influence of a PMMA contact lens. The contact lens had also appeared to decrease variation in corneal curvature. There was no control study done on this eye therefore the effects of diurnal variation, if any, could not be established. (S Afr Optom 2010 69(2 69-76

  3. Applying Taguchi methods for solvent-assisted PMMA bonding technique for static and dynamic micro-TAS devices.

    Science.gov (United States)

    Hsu, Yi-Chu; Chen, Tang-Yuan

    2007-08-01

    This work examines numerous significant process parameters in the solvent-assistant Polymethyl methacrylate (PMMA) bonding scheme and presents two Micro-total-analysis System (micro-TAS) devices generated by adopting the optimal bonding parameters. The process parameters considered were heating temperature, applied loading, duration and solution. The effects of selected process parameters on bonding dimensions loss and strength, and subsequent optimal setting of the parameters were accomplished using Taguchi's scheme. Additionally, two micro-TAS devices were realized using a static paraffin microvalve and a dynamic diffuser micropump. The PMMA chips were carved using a CO2 laser that patterned device microchannels and microchambers. The operation principles, fabrication processes and experimental performance of the devices are discussed. This bonding technique has numerous benefits, including high bonding strength (240 kgf/cm2) and low dimension loss (2-6%). For comparison, this work also demonstrates that the normal stress of this technology is 2-15 times greater than that of other bonding technologies, including hot embossing, anodic bonding, direct bonding and thermal fusion bonding.

  4. Antibiofilm properties of silver and gold incorporated PU, PCLm, PC and PMMA nanocomposites under two shear conditions.

    Directory of Open Access Journals (Sweden)

    Shilpa N Sawant

    Full Text Available Silver and gold nanoparticles (of average size ∼20-27 nm were incorporated in PU (Polyurethane, PCLm (Polycaprolactam, PC (polycarbonate and PMMA (Polymethylmethaacrylate by swelling and casting methods under ambient conditions. In the latter method the nanoparticle would be present not only on the surface, but also inside the polymer. These nanoparticles were prepared initially by using a cosolvent, THF. PU and PCLm were dissolved and swollen with THF. PC and PMMA were dissolved in CHCl₃ and here the cosolvent, THF, acted as an intermediate between water and CHCl₃. FTIR indicated that the interaction between the polymer and the nanoparticle was through the functional group in the polymer. The formation of E.coli biofilm on these nanocomposites under low (in a Drip flow biofilm reactor and high shear (in a Shaker conditions indicated that the biofilm growth was higher (twice in the former than in the latter (ratio of shear force = 15. A positive correlation between the contact angle (of the virgin surface and the number of colonies, carbohydrate and protein attached on it were observed. Ag nanocomposites exhibited better antibiofilm properties than Au. Bacterial attachment was highest on PC and least on PU nanocomposite. Casting method appeared to be better than swelling method in reducing the attachment (by a factor of 2. Composites reduced growth of organisms by six orders of magnitude, and protein and carbohydrate by 2-5 times. This study indicates that these nanocomposites may be suitable for implant applications.

  5. Preparation and application of cross-linked core-shell PBA/PS and PBA/PMMA nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Zeng Zhong; Yu Jian; Guo Zhaoxia; Li Ying

    2006-01-01

    This paper reports the preparation of crosslinked core-shell poly(butyl acrylate )/polystyrene (PBA/PS)and poly(butyl acrylate)/poly(methyl methacrylate) (PBA/PMMA) nanoparticles via seeded emulsion polymerization and their application in nylon-based composites.A highly cross-linked structure was formed in both the cores and the shells by using a cross-linking agent,which could prevent the migration of hydrophobic PS shells tO the inside of particles.There were covalent bonds on the interfaces between the cores and the shells of both particles.The average particle sizes were 40-50 nm,and the size distributions were narrow.The kinetics of polymerization was investigated.Well-defined core-shell structure and narrow particle size distribution could be achieved under starved conditions of monomer feeding.Furthermore,PBA/PMMA particles were used to fill nylon 6,good dispersion was obtained because of the strong interfacial interaction between the nanoparticles and the nylon 6 matrix and the good deformation ability of nanoparticles,and the toughness and rigidity of the composites were improved evidently.

  6. Mechanical behavior of PMMA due to artificial aging by means of a xenon-test chamber; Comportamiento mecanico del polimetilmetacrilato sometido a envejecimiento artificial mediante camara xenotest

    Energy Technology Data Exchange (ETDEWEB)

    Colom, X.; Nogues, F.; Valldeperas, J.; Carrillo, F.; Gordillo, A.

    2001-07-01

    In this investigation, the mechanical behavior of poly(methylmethacrylate) due to aging in Xenon test chamber, using a xenon-arch lamp as alight radiation to simulate natural sun light has been studied. This work studies the mechanical properties (elongation at break, Young's modules, tensile strength and toughness) of PMMA samples exposed to different aging conditions (until 1560 h xenotest that correspond to 750 days exposure at natural light). The evolution of different mechanical properties characterizes the PMMA's process of degradation. (Author) 10 refs.

  7. Improvement of ionic conductivity and performance of quasi-solid-state dye sensitized solar cell using PEO/PMMA gel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Aram, E. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Ehsani, M., E-mail: m.ehsani@ippi.ac.ir [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Khonakdar, H.A. [Iran Polymer and Petrochemical Institute, 14965/115 Tehran (Iran, Islamic Republic of); Leibniz Institute of Polymer Research, D-01067 Dresden (Germany)

    2015-09-10

    Graphical abstract: Reduced interfacial resistance of a quasi-solid-state dye sensitized solar cell with PEO/PMMA blend gel electrolytes. - Highlights: • A new polymer gel electrolyte containing PEO/PMMA was developed for DSSCs. • Optimization of polymer gel electrolyte was done for dye sensitized solar cell. • The best ionic conductivity was found in PEO/PMMA blend with 10/90 w/w composition. • The DSSC with the PEO/PMMA based electrolyte showed good photovoltaic performance. • Significant stability improvement for quasi-solid state DSSC was obtained. - Abstract: Polymer blend gel electrolytes based on polyethylene oxide (PEO) and poly(methyl methacrylate) (PMMA) as host polymers with various weight ratios, LiI/I{sub 2} as redox couple in electrolyte and 4-tert-butyl pyridine as additive were prepared by solution method. The introduction of PMMA in the PEO gel electrolyte reduced the degree of crystallinity of PEO, which was confirmed by differential scanning calorimetry (DSC). Complexation and ionic conductivity as a function of temperature were investigated with Fourier transform infrared and ionic conductometry, respectively. A good correlation was found between the degree of crystallinity and ionic conductivity. The reduction in crystallinity, governed by blending ratio, led to improvement of ionic conductivity. The best ionic conductivity was attained in PEO/PMMA blend with 10/90 w/w composition. The performance of a quasi-solid-state dye sensitized solar cell using the optimized polymer gel electrolyte was investigated. The optimized system of high ionic conductivity of 7 mS cm{sup −1}, with fill factor of 0.59, short-circuit density of 11.11 mA cm{sup −2}, open-circuit voltage of 0.75 V and the conversion efficiency of 4.9% under air mass 1.5 irradiation (100 mW cm{sup −2}) was obtained. The long-term stability of the dye-sensitized solar cell (DSSC) during 600 h was improved by using PEO/PMMA gel electrolyte relative to a liquid type

  8. Nonlinear optical properties of poly(methyl methacrylate) thin films doped with Bixa Orellana dye

    Energy Technology Data Exchange (ETDEWEB)

    Zongo, S., E-mail: sidiki@tlabs.ac.za [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); Kerasidou, A.P. [LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France); Sone, B.T.; Diallo, A. [UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria (South Africa); Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); Mthunzi, P. [Council for Scientific and Industrial Research, P O Box 395, Pretoria 0001 (South Africa); Iliopoulos, K. [LUNAM Université, Université d’Angers, CNRS UMR 6200, Laboratoire MOLTECH-Anjou, 2 Bd Lavoisier, 49045 Angers Cedex (France); Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras (Greece); Nkosi, M. [Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province (South Africa); and others

    2015-06-15

    Highlights: • We studied the linear and nonlinear optical properties of hybrid Bixa Orellana dye doped PMMA thin film. • We investigated the linear optical properties by means of UV/Vis, FTIR and Fluorescence. • We used Tauc - Lorentz model to evaluate linear optical parameters (n &k) with relative maximum of 1.456 at 508.5, 523.79 and 511.9 nm for n is observed while the maximum of k varies from 0.070 to 0.080. • We evaluated nonlinear third order susceptibility which was found to be 1.00 × 10{sup −21} m{sup 2} V{sup −2} or 0.72 × 10{sup −13} esu. - Abstract: Natural dyes with highly delocalized π-electron systems are considered as promising organic materials for nonlinear optical applications. Among these dyes, Bixa Orellana dye with extended π-electron delocalization is one of the most attractive dyes. Bixa Orellana dye-doped Poly(methyl methacrylate) (PMMA) thin films were prepared through spin coating process for linear and nonlinear optical properties investigation. Atomic force microscopy (AFM) was used to evaluate the roughness of the thin films. The optical constants n and k were evaluated by ellipsometric spectroscopy. The refractive index had a maximum of about 1.456 at 508.5, 523.79 and 511.9 nm, while the maximum of k varies from 0.070 to 0.080 with the thickness. The third order nonlinear optical properties of the hybrid Bixa Orellana dye-PMMA polymer were investigated under 30 ps laser irradiation at 1064 nm with a repetition rate of 10 Hz. In particular the third-order nonlinear susceptibility has been determined by means of the Maker Fringes technique. The nonlinear third order susceptibility was found to be 1.00 × 10{sup −21} m{sup 2} V{sup −2} or 0.72 × 10{sup −13} esu. Our studies provide concrete evidence that the hybrid-PMMA composites of Bixa dye are prospective candidates for nonlinear material applications.

  9. Metal nanoparticles for thin film solar cells

    DEFF Research Database (Denmark)

    Gritti, Claudia

    and used for FTDT simulations, in order to identify the set of parameters (NPs size and array periodicity) which could show LSP resonance in the NIR range. Two techniques are here used to fabricate NPs: electron beam lithography (EBL), to deposit ordered arrays of gold and silver NPs, simple to be compared...... the solar cell structure (GaAs, SiO2, Si3N4, AZO/Cr), in order to investigate the LSP resonance and tune it to exploit it below the energy band gap of the semiconductor. EBL is a difficult technique when working by lift-off on critical size (20-50 nm) nanoparticles. The optimization of the process saw...... a change from ZEP resist to double layer of PMMA and always requires preliminary exposure dose-tests and final particular attention for lift-off step. EBL resulted to be more suitable for silver NPs, since the deposition of gold (on top of an adhesion thin titanium layer) leads to a variation and non...

  10. The effects of solvents on the properties of ultra-thin poly (methyl methacrylate) films prepared by spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Tippo, T. [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand); Thanachayanont, C.; Muthitamongkol, P.; Junin, C. [National Metal and Materials Technology Center, Thailand Science Park, Klong 1, KlongLuang, Pathumthani 12120 (Thailand); Hietschold, M. [Chemnitz University of Technology, Institute of Physics, Solid Surface Analysis Group, D-09107 Chemnitz (Germany); Thanachayanont, A., E-mail: ktapinun@kmitl.ac.th [Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Chalongkrung Road, Ladkrabang, Bangkok 10520 (Thailand)

    2013-11-01

    Poly (methyl methacrylate) (PMMA) is extensively used as an insulating layer in organic electronic devices. In this study, spin coating method was used to cast thin layers of PMMA for dielectric application from solutions in three different solvents, namely dimethylformamide (DMF), n-butyl acetate and toluene. The solvent's vapor pressure causes the solvent to vaporize at different rates leading to layer's distortion and different surface roughnesses. Preparation of suitable surface morphologies, for example, pinhole-free and crack-free was studied. A step profilometer was used to measure the film thicknesses. Alternatively an equation correlating final film thickness to spin speed and solution concentration was proposed. A metal/insulator/metal parallel plate capacitor structure was fabricated and the current density dependence on the applied electric field was measured. The resulting low surface roughness, low leakage currents, high breakdown voltage, and high dielectric constant were obtained for the 100 nm-thick PMMA film prepared with DMF. - Highlights: • Solvent effect on quality of poly (methyl methacrylate) films • Thickness, surface morphology, and electrical properties were studied. • Best surface morphology and electrical properties obtained using dimethylformamide.

  11. Simulation of the secondary electrons energy deposition produced by proton beams in PMMA: influence of the target electronic excitation description

    Science.gov (United States)

    Dapor, Maurizio; Abril, Isabel; de Vera, Pablo; Garcia-Molina, Rafael

    2015-06-01

    We have studied the radial dependence of the energy deposition of the secondary electron generated by swift proton beams incident with energies T = 50 keV-5 MeV on poly(methylmethacrylate) (PMMA). Two different approaches have been used to model the electronic excitation spectrum of PMMA through its energy loss function (ELF), namely the extended-Drude ELF and the Mermin ELF. The singly differential cross section and the total cross section for ionization, as well as the average energy of the generated secondary electrons, show sizeable differences at T ⩽ 0.1 MeV when evaluated with these two ELF models. In order to know the radial distribution around the proton track of the energy deposited by the cascade of secondary electrons, a simulation has been performed that follows the motion of the electrons through the target taking into account both the inelastic interactions (via electronic ionizations and excitations as well as electron-phonon and electron trapping by polaron creation) and the elastic interactions. The radial distribution of the energy deposited by the secondary electrons around the proton track shows notable differences between the simulations performed with the extended-Drude ELF or the Mermin ELF, being the former more spread out (and, therefore, less peaked) than the latter. The highest intensity and sharpness of the deposited energy distributions takes place for proton beams incident with T ~ 0.1-1 MeV. We have also studied the influence in the radial distribution of deposited energy of using a full energy distribution of secondary electrons generated by proton impact or using a single value (namely, the average value of the distribution); our results show that differences between both simulations become important for proton energies larger than ~0.1 MeV. The results presented in this work have potential applications in materials science, as well as hadron therapy (due to the use of PMMA as a tissue phantom) in order to properly consider the

  12. Prediction of the percolation threshold and electrical conductivity of self-assembled antimony-doped tin oxide nanoparticles into ordered structures in PMMA/ATO nanocomposites.

    Science.gov (United States)

    Jin, Youngho; Gerhardt, Rosario A

    2014-12-24

    Electrical percolation in nanocomposites consisting of poly(methyl methacrylate) (PMMA) and antimony tin oxide (ATO) nanoparticles was investigated experimentally using monosize and polydisperse polymer particles. The nanocomposites were fabricated by compression molding at 170 °C. The matrix PMMA was transformed into space filling polyhedra while the ATO nanoparticles distributed along the sharp edges of the matrix, forming a 3D interconnected network. The measured electrical resistivity showed that percolation was achieved in these materials at a very low ATO content of 0.99 wt % ATO when monosize PMMA was used, whereas 1.48 wt % ATO was needed to achieve percolation when the PMMA was polydispersed. A parametric finite element approach was chosen to model this unique microstructure-driven self-assembling percolation behavior. COMSOL Multiphysics was used to solve the effects of phase segregation between the matrix and the filler using a 2D simplified model in the frequency domain of the AC/DC module. It was found that the percolation threshold (pc) is affected by the size ratio between the matrix and the filler in a systematic way. Furthermore, simulations indicate that small deviations from perfect interconnection result mostly in changes in the electrical resistivity while the minimum DC resistivity achievable in any given composite is governed by the electrical conductivity of the filler, which must be accurately known in order to obtain an accurate prediction. The model is quite general and is able to predict percolation behavior in a number of other similarly processed segregated network nanocomposites.

  13. Studies of optical, morphological and electrical properties of POMA/PMMA blends, using two different levels of doping with CSA

    Directory of Open Access Journals (Sweden)

    Nizamara S. Pereira

    2012-01-01

    Full Text Available Poly(o-methoxyaniline (POMA was synthesized by oxidative polymerization of the monomer o-methoxyaniline. POMA/poly(methyl methacrylate (PMMA blends were produced by dissolving both polymers in chloroform (CHCl3.The amount of camphor sulfonic acid (CSA used as dopant of POMA was different, providing two methods for preparation of the blends. Solutions were analyzed by Fourier transform infrared spectroscopy (FTIR and then deposited on glass substrate by spin coating for characterization by atomic force microscope (AFM and current versus voltage (I × V curves. FTIR spectra of solutions were similar as expected. In the AFM images a reduction and/or loss of globules common in conducting polymers (CP such as polyaniline (PANI and its derivatives was observed. Films produced with different amounts of CSA presented distinct, linear and non-linear I × V curves.

  14. CO2-laser micromachining and back-end processing for rapid production of PMMA-based microfluidic systems

    DEFF Research Database (Denmark)

    Klank, Henning; Kutter, Jörg Peter; Geschke, Oliver

    2002-01-01

    , a three-layer polymer microstructure with included optical fibers was fabricated within two days. The use of CO2-laser systems to produce microfluidic systems has not been published before. These systems provide a cost effective alternative to UV-laser systems and they are especially useful...... for microstructured PMMA [poly( methyl methacrylate)] parts were investigated, such as solvent-assisted glueing, melting, laminating and surface activation using a plasma asher. A solvent-assisted thermal bonding method proved to be the most time-efficient one. Using laser micromachining together with bonding......In this article, we focus on the enormous potential of a CO2-laser system for rapidly producing polymer microfluidic structures. The dependence was assessed of the depth and width of laser-cut channels on the laser beam power and on the number of passes of the beam along the same channel...

  15. Comparison of the Retinal Straylight in Pseudophakic Eyes with PMMA, Hydrophobic Acrylic, and Hydrophilic Acrylic Spherical Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Ya-wen Guo

    2014-01-01

    Full Text Available Purpose. To investigate the intraocular straylight value after cataract surgery. Methods. In this study, 76 eyes from 62 patients were subdivided into three groups. A hydrophobic acrylic, a hydrophilic acrylic, and a PMMA IOL were respectively, implanted in 24 eyes, 28 eyes, and 24 eyes. Straylight was measured using C-Quant at 1 week and 1 month postoperatively in natural and dilated pupils. Results. The hydrophilic acrylic IOLs showed significantly lower straylight values than those of the hydrophobic acrylic IOLs in dilated pupils at 1 week and 1 month after surgery (P0.05. Moreover, no significant difference was found in straylight between natural and dilated pupils in each group at 1 week and 1 month postoperatively (P>0.05. Conclusions. Although the hydrophobic acrylic IOL induced more intraocular straylight, straylight differences among the 3 IOLs were minimal. Pupil size showed no effect on intraocular straylight; the intraocular straylight was stable 1 week after surgery.

  16. A Mössbauer study of the chemical stability of iron oxide nanoparticles in PMMA and PVB beads

    Science.gov (United States)

    Chen, Wei; Mørup, Steen; Hansen, Mikkel F.; Banert, Tobias; Peuker, Urs A.

    We have prepared magnetic beads consisting of iron oxide nanoparticles in a polymethyl methacrylate (PMMA) and a polyvinyl butyral (PVB) matrix. High-field Mössbauer studies show that the particles have an almost perfect collinear spin structure and magnetization measurements show that they are superparamagnetic at room temperature at a time scale of seconds. We have followed the oxidation of the particles, which initially have a stoichiometry close to magnetite. The oxidation is fast during the first 2-3 weeks and then continues slowly such that even after 30 weeks the particles have not completely transformed to maghemite. The PVB beads are hydrophilic and biocompatible and are therefore well suited for applications in medicine and biology.

  17. Dyeing, moisture regain and mechanical properties of wool fabric grafted with PMMA by chemical and radiation-initiated methods

    Energy Technology Data Exchange (ETDEWEB)

    El Naggar, A.M.; Marie, M.M.; El Gendy, E.H.; El Miligy, A.A. [National Centre for Radiation Research and Technology, Cairo (Egypt)

    1996-04-01

    PMMA polymer has been grafted onto wool fabric by two methods of grafting preirradiation method and chemical initiation using KMnO{sub 4}/H{sub 2}SO{sub 4} system. The grafted wool showed an enhancement in dyeability towards some basic dyes differing in size and chemical structure. Preirradiated grafted wool exhibited a relatively higher dyeing affinity than that prepared by the chemical method. Graft yield of up to 26% of PPMA did not have a noticeable effect on the moisture regain of wool fabric. Further increase in graft yield was found to cause a slight reduction in moisture regain. The tensile strength was reduced by the graft process, but elongation at break was not affects. (author).

  18. AC ionic conductivity and DC polarization method of lithium ion transport in PMMA-LiBF4 gel polymer electrolytes

    Science.gov (United States)

    Osman, Z.; Mohd Ghazali, M. I.; Othman, L.; Md Isa, K. B.

    2012-01-01

    Polymethylmethacrylate (PMMA)-based gel polymer electrolytes comprising ethylene carbonate-propylene carbonate (EC/PC) mixed solvent plasticizer and various concentrations of lithium tetrafluoroborate (LiBF4) salt are prepared using a solvent casting technique. Electrical conductivity and transference number measurements were carried out to investigate conductivity and charge transport in the gel polymer electrolytes. The conductivity results show that the ionic conductivity of the samples increases when the amount of salt is increased, however decreases after reaching the optimum value. This result is consistent with the transference number measurements. The conductivity-frequency dependence plots show two distinct regions; i.e. at lower frequencies the conductivity increases with increasing frequency and the frequency independent plateau region at higher frequencies. The temperature-dependence conductivity of the films seems to obey the Arrhenius rule.

  19. Nuclear reaction measurements of 95 MeV/u {sup 12}C interactions on PMMA for hadrontherapy

    Energy Technology Data Exchange (ETDEWEB)

    Braunn, B. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Labalme, M., E-mail: labalme@lpccaen.in2p3.fr [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Ban, G. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Chevallier, M. [IPN Lyon (France); Colin, J.; Cussol, D. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Dauvergne, D. [IPN Lyon (France); Fontbonne, J.M. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Haas, F. [IPHC Strasbourg (France); Guertin, A. [SUBATECH, CNRS/IN2P3, Ecole des Mines et Universite de Nantes, Nantes (France); Lebhertz, D. [IPHC Strasbourg (France); Le Foulher, F. [IPN Lyon (France); Pautard, C. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, Caen (France); Ray, C. [IPN Lyon (France); Rousseau, M. [IPHC Strasbourg (France); Salsac, M.D. [CEA/IRFU/SPhN Saclay (France); Stuttge, L. [IPHC Strasbourg (France); Testa, E.; Testa, M. [IPN Lyon (France)

    2011-11-15

    The ion dose deposition in tissues is characterized by a favorable depth dose profile (i.e. Bragg peak) and a small lateral spread. In order to keep these benefits of ions in cancer treatments, a very high accuracy is required on the dose deposition ({+-}3%). For given target stoichiometry and geometry, the largest uncertainty on the physical dose deposition is due to the ion nuclear fragmentation. We have performed an experiment at GANIL with a 95 MeV/u {sup 12}C beam on thick tissue equivalent PMMA targets (thicknesses: 5, 10, 15, 20 and 25 mm). The main goals of this experiment are to provide experimental fragmentation data for benchmarking the physical models used for treatment planning. Production rates, energy and angular distributions of charged fragments have been measured. The purpose of this paper is to present the results of this experiment.

  20. Ionic transport studies in PVDF-HFP-PMMA-(PC+DEC)-LiClO4 gel polymer electrolyte

    Science.gov (United States)

    Gohel, Khushbu; Kanchan, D. K.

    2017-05-01

    Poly(vinylidene fluoride-hexafluropropylene)(PVdF-HFP) and Polymethylmethacrylate(PMMA) based gel polymer electrolytes comprising Propylene Carbonate and Diethyl Carbonate mixed plasticizers and different concentrations of Lithium Perchlorate (LiClO4) salt have been prepared using a solvent casting technique. Electrical conductivity and transference number measurements have been carried out by Electrochemical Impedance Spectroscopy in the temperature range 303 K to 363 K and Wagner's Polarization method respectively. The maximum room temperature conductivity of 2.83 ×10-4 S cm-1 has been observed for the gel polymer electrolytes at 7.5 wt% LiClO4. The variation of ac conductivity with frequency has been discussed.

  1. Electrodeposition of polymer electrolyte in nanostructured electrodes for enhanced electrochemical performance of thin-film Li-ion microbatteries

    Science.gov (United States)

    Salian, Girish D.; Lebouin, Chrystelle; Demoulin, A.; Lepihin, M. S.; Maria, S.; Galeyeva, A. K.; Kurbatov, A. P.; Djenizian, Thierry

    2017-02-01

    We report that electrodeposition of polymer electrolyte in nanostructured electrodes has a strong influence on the electrochemical properties of thin-film Li-ion microbatteries. Electropolymerization of PMMA-PEG (polymethyl methacrylate-polyethylene glycol) was carried out on both the anode (self-supported titania nanotubes) and the cathode (porous LiNi0.5Mn1.5O4) by cyclic voltammetry and the resulting electrode-electrolyte interface was examined by scanning electron microscopy. The electrochemical characterizations performed by galvanostatic experiments reveal that the capacity values obtained at different C-rates are doubled when the electrodes are completely filled by the polymer electrolyte.

  2. Manufacturing and characterisation of PMMA-graphene oxide (GO nanocomposite sandwich films with electrospun nano-fibre core

    Directory of Open Access Journals (Sweden)

    D. Bhattacharyya

    2012-12-01

    Full Text Available Purpose: Nanocomposite materials, comprising of polymer matrices and nano-sized reinforcements, exhibit significantly enhanced mechanical and functional properties at extremely low filler loading. In recent years, graphene oxide (GO has emerged as a new class of low cost nano-filler with high mechanical strength and stiffness, and alterable electrical properties. For nano-fillers with layered structure like GO, complete exfoliation and uniform dispersion of filler in the polymer matrices is essential to enhance the matrix-filler interaction and in turn the mechanical and/or functional property improvement. Conventional nanocomposite manufacturing methods including in-situ polymerisation and solvent processing encounter the problem of agglomeration of GO films. Additionally, its low bulk density presents difficulties in handling, and the energy requirement for mechanical mixing and extrusion processes is very high. In this work, we report manufacturing of poly(methyl methacrylate–graphene oxide (PMMA-GO nano-fibre mat using relatively novel approach of employing electrospinning technique. The manufactured electrospun core was inserted between plain polymer layers to prepare a robust and easy to handle sandwich film. Morphology and structure of the PMMA-GO nano-fibre cores was evaluated with scanning and transmission electron microscopy and X-ray diffractometry. The manufactured nano-fibre mat samples exhibited uniform diameter and dispersion. The functional parameters including thermal stability and gas barrier were evaluated with differential scanning calorimetry and oxygen permeation testing, and these functional properties were observed to be superior to that of monolithic polymer counterparts.

  3. Experimental and scale up study of the flame spread over the PMMA sheets

    Directory of Open Access Journals (Sweden)

    Mamourian Mojtaba

    2009-01-01

    Full Text Available To explore the flame spread mechanisms over the solid fuel sheets, downward flame spread over vertical polymethylmethacrylate sheets with thicknesses from 1.75 to 5.75 mm have been examined in the quiescent environment. The dependence of the flame spread rate on the thickness of sheets is obtained by one-dimensional heat transfer model. An equation for the flame spread rate based on the thermal properties and the thickness of the sheet by scale up method is derived from this model. During combustion, temperature within the gas and solid phases is measured by a fine thermocouple. The pyrolysis temperature, the length of the pyrolysis zone, the length of the preheating zone, and the flame temperature are determined from the experimental data. Mathematical analysis has yielded realistic results. This model provides a useful formula to predict the rate of flame spread over any thin solid fuel.

  4. Thin film processes II

    CERN Document Server

    Kern, Werner

    1991-01-01

    This sequel to the 1978 classic, Thin Film Processes, gives a clear, practical exposition of important thin film deposition and etching processes that have not yet been adequately reviewed. It discusses selected processes in tutorial overviews with implementation guide lines and an introduction to the literature. Though edited to stand alone, when taken together, Thin Film Processes II and its predecessor present a thorough grounding in modern thin film techniques.Key Features* Provides an all-new sequel to the 1978 classic, Thin Film Processes* Introduces new topics, and sever

  5. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  6. Characterization of a new composite PMMA-HA/Brushite bone cement for spinal augmentation.

    Science.gov (United States)

    Aghyarian, Shant; Rodriguez, Lucas C; Chari, Jonathan; Bentley, Elizabeth; Kosmopoulos, Victor; Lieberman, Isador H; Rodrigues, Danieli C

    2014-11-01

    Calcium phosphate fillers have been shown to increase cement osteoconductivity, but have caused drawbacks in cement properties. Hydroxyapatite and Brushite were introduced in an acrylic two-solution cement at varying concentrations. Novel composite bone cements were developed and characterized using rheology, injectability, and mechanical tests. It was hypothesized that the ample swelling time allowed by the premixed two-solution cement would enable thorough dispersion of the additives in the solutions, resulting in no detrimental effects after polymerization. The addition of Hydroxyapatite and Brushite both caused an increase in cement viscosity; however, these cements exhibited high shear-thinning, which facilitated injection. In gel point studies, the composite cements showed no detectable change in gel point time compared to an all-acrylic control cement. Hydroxyapatite and Brushite composite cements were observed to have high mechanical strengths even at high loads of calcium phosphate fillers. These cements showed an average compressive strength of 85 MPa and flexural strength of 65 MPa. A calcium phosphate-containing cement exhibiting a combination of high viscosity, pseudoplasticity and high mechanical strength can provide the essential bioactivity factor for osseointegration without sacrificing load-bearing capability.

  7. Study of excitation energy transfer from Coumarin102(donor) to Coumarin6(acceptor) doped in poly-methyl methacrylate (PMMA) thin film

    Science.gov (United States)

    Singh, Khushboo; Negi, Gauri; Joshi, G. C.

    2015-05-01

    Energy transfer from Coumarin102 to Coumarin6 has been studied. It is observed that energy transfer begins at relatively larger donor acceptor separations than the critical transfer distance for efficient dipole-dipole energy transfer by Forster mechanism. For Coumarin 102 and Coumarin 6 dye pair, the energy transfer parameters, viz overlap integral(J(λ)) and Förster distance(R0), equaling 3.4x10-13M-1cm3 and 58.7(Å), respectively have been obtained. Migration through donor-donor interaction is suggested to be the possible mechanism and Huber model has been applied to calculate the transfer rate.

  8. The effect of the accelerated aging on the mechanical properties of the PMMA denture base materials modified with itaconates

    Directory of Open Access Journals (Sweden)

    Spasojević Pavle M.

    2011-01-01

    Full Text Available This study evaluated the effect of accelerated ageing on the tensile strength, elongation at break, hardness and Charpy impact strength in commercial PMMA denture base material modified with di-methyl itaconate (DMI and di-n-butyl itaconate (DBI. The samples were prepared by modifying commercial formulation by addition of itaconates in the amounts of 2.5, 5, 7.5 and 10% by weight. After polymerization samples were characterized by FT-IR and DSC analysis while residual monomer content was determined by HPLC-UV. Accelerated ageing was performed at 70°C in water for periods of 7, 15 and 30 days. Tensile measurements were performed using Instron testing machine while the hardness of the polymerized samples was measured by Shore D method. The addition of itaconate significantly reduces the residual MMA. Even at the small amounts of added itaconates (2.5% the residual MMA content was reduced by 50%. The increase of itaconate content in the system leads to the decrease of residual MMA. It has been found that the addition of di-n-alkyl itaconates decreases the tensile strength, hardness and Charpy impact strength and increases elongation at break. Samples modified with DMI had higher values of tensile strength, hardness and Charpy impact strength compared to the ones modified with DBI. This is explained by the fact that DBI has longer side chain compared to DMI. After accelerated ageing during a 30 days period the tensile strength decreased for all the investigated samples. The addition of DMI had no effect on the material ageing and the values for the tensile strength of all of the investigated samples decreased around 20%, while for the samples modified with DBI, the increase of the amount of DBI in the polymerized material leads to the higher decrease of the tensile strength after the complete accelerated ageing period od 30 days, aulthough after the first seven days of the accelerated ageing the values of hardness have increased for all of the

  9. PMMA/SAN共混体系的热膨胀系数和等温压缩系数测定%DETERMINATION OF THE THERMAL EXPANSIVITY AND COMPRESSIBILITY FOR PMMA/SAN BLENDS

    Institute of Scientific and Technical Information of China (English)

    文纲要; 孙昭艳; 杨剑; 安立佳

    2002-01-01

    通过溶液共混制得不同组成的聚甲基丙烯酸甲酯(PMMA)和苯乙烯-丙烯腈共聚物(SAN,其中AN的含量约为30%(质量))的共混物.利用压力-体积-温度(pVT)膨胀仪对PMMA、SAN纯组分样品及各共混物分别进行了测量,得到了它们的比容Vsp随温度T和压力p变化的关系(pVT数据),计算出它们的热膨胀系数α随温度变化的关系以及等温压缩系数β随压力变化的关系.在此基础上,拟合出共混物的α和β分别随组成变化的关系式.此外,应用Tait方程对所有样品的pVT数据进行了拟合.

  10. Secondary radiation measurements for particle therapy applications: Charged secondaries produced by 4He and 12C ion beams in a PMMA target at large angle

    CERN Document Server

    Rucinski, A; Battistoni, G; Collamati, F; Faccini, R; Frallicciardi, P M; Mancini-Terracciano, C; Marafini, M; Mattei, I; Muraro, S; Paramatti, R; Piersanti, L; Pinci, D; Russomando, A; Sarti, A; Sciubba, A; Camillocci, E Solfaroli; Toppi, M; Traini, G; Voena, C; Patera, V

    2016-01-01

    Measurements performed with the purpose of characterizing the charged secondary radiation for dose release monitoring in particle therapy are reported. Charged secondary yields, energy spectra and emission profiles produced in poly-methyl methacrylate (PMMA) target by 4He and 12C beams of different therapeutic energies were measured at 60 and 90 degree with respect to the primary beam direction. The secondary yields of protons produced along the primary beam path in PMMA target were obtained. The energy spectra of charged secondaries were obtained from time-of-flight information, whereas the emission profiles were reconstructed exploiting tracking detector information. The measured charged secondary yields and emission profiles are in agreement with the results reported in literature and confirm the feasibility of ion beam therapy range monitoring using 12C ion beam. The feasibility of range monitoring using charged secondary particles is also suggested for 4He ion beam.

  11. PMMA-Etching-Free Transfer of Wafer-scale Chemical Vapor Deposition Two-dimensional Atomic Crystal by a Water Soluble Polyvinyl Alcohol Polymer Method

    Science.gov (United States)

    van Ngoc, Huynh; Qian, Yongteng; Han, Suk Kil; Kang, Dae Joon

    2016-09-01

    We have explored a facile technique to transfer large area 2-Dimensional (2D) materials grown by chemical vapor deposition method onto various substrates by adding a water-soluble Polyvinyl Alcohol (PVA) layer between the polymethyl-methacrylate (PMMA) and the 2D material film. This technique not only allows the effective transfer to an arbitrary target substrate with a high degree of freedom, but also avoids PMMA etching thereby maintaining the high quality of the transferred 2D materials with minimum contamination. We applied this method to transfer various 2D materials grown on different rigid substrates of general interest, such as graphene on copper foil, h-BN on platinum and MoS2 on SiO2/Si. This facile transfer technique has great potential for future research towards the application of 2D materials in high performance optical, mechanical and electronic devices.

  12. Structural and ionic conductivity studies of electrospun polymer blend P(VdF-co-HFP)/PMMA electrolyte membrane for lithium battery application

    Energy Technology Data Exchange (ETDEWEB)

    Padmaraj, O.; Satyanarayana, N., E-mail: nallanis2011@gmail.com [Department of Physics, Pondicherry University, Pondicherry 605 014 (India); Venkateswarlu, M. [R& D, Amara Raja Batteries Ltd., Karakambadi 517 520 (India)

    2015-06-24

    A novel fibrous polymer blend [(100-x) % P(VdF-co-HFP)/x % PMMA, x = 10, 20, 30, 40, 50] electrolyte membranes were prepared by electrospinning technique. Structural, thermal and surface morphology of all the compositions of electrospun polymer blend membranes were studied by using XRD, DSC & SEM. The newly developed five different compositions of polymer blend fibrous electrolyte membranes were obtained by soaking in an electrolyte solution contains 1M LiPF{sub 6} in EC: DEC (1:1,v/v). The wet-ability and conductivity of all the compositions of polymer blend electrolyte membranes are evaluated through electrolyte uptake and impedance measurements. The polymer blend [90% P(VdF-co-HFP)/10% PMMA] electrolyte membrane showed good wet-ability and high conductivity (1.788 × 10{sup −3} Scm{sup −1}) at room temperature.

  13. Control of physical properties of carbon nanofibers obtained from coaxial electrospinning of PMMA and PAN with adjustable inner/outer nozzle-ends.

    Science.gov (United States)

    Kaerkitcha, Navaporn; Chuangchote, Surawut; Sagawa, Takashi

    2016-12-01

    Hollow carbon nanofibers (HCNFs) were prepared by electrospinning method with several coaxial nozzles, in which the level of the inner nozzle-end is adjustable. Core/shell nanofibers were prepared from poly(methyl methacrylate) (PMMA) as a pyrolytic core and polyacrylonitrile (PAN) as a carbon shell with three types of normal (viz. inner and outer nozzle-ends are balanced in the same level), inward, and outward coaxial nozzles. The influence of the applied voltage on these three types of coaxial nozzles was studied. Specific surface area, pore size diameter, crystallinity, and degree of graphitization of the hollow and mesoporous structures of carbon nanofibers obtained after carbonization of the as spun PMMA/PAN nanofibers were characterized by BET analyses, X-ray diffraction, and Raman spectroscopy in addition to the conductivity measurements. It was found that specific surface area, crystallinity, and graphitization degree of the HCNFs affect the electrical conductivity of the carbon nanofibers.

  14. Effect of PVC on ionic conductivity, crystallographic structural, morphological and thermal characterizations in PMMA-PVC blend-based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, S., E-mail: rameshtsubra@gmail.com [Centre for Ionics University Malaya, Department of Physics, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Liew, Chiam-Wen; Morris, Ezra; Durairaj, R. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak, 53300 Kuala Lumpur (Malaysia)

    2010-11-20

    In this paper, temperature dependence of ionic conductivity, crystallographic structural, morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as a dopant salt are investigated. The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior. The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes, respectively. In DSC analysis it was found that the glass transition temperature (T{sub g}) and melting temperature (T{sub m}) decreased, whereas the decomposition temperature (T{sub d}) increased. In contrast, the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes, in TGA studies, indicates that the thermal stability of polymer electrolytes improved.

  15. Preparation of microspheres containing methyl methacrylate (MMA) with magnetic nanoparticles; Preparacao de microesferas contendo metacrilato de metila (PMMA) com nanoparticulas magneticas

    Energy Technology Data Exchange (ETDEWEB)

    Feuser, P.E.; Souza, M.N. de, E-mail: paulofeuser@hotmail.co, E-mail: nele@eq.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Engenharia Quimica

    2010-07-01

    Magnetic nanoparticles have found many technological applications and has been intensively studied due to its special magnetic properties. In most biomedical applications, microspheres containing magnetic nanoparticles is used as a vehicle for transporting drugs, presenting several advantages when compared to other conventional methods. PMMA is a polymer which has biocompatibility and can be used for the encapsulation of magnetic nanoparticles, showing a great degree of saturation magnetization. PMMA microparticles containing magnetic nanoparticles were prepared by suspension polymerization. Polymers containing magnetic nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetization, thermogravimetric analysis, optical microscopy, chromatography gel permeation, analysis of particle size - malversizer 2000 (Malvern Instruments). The average size of magnetic nanoparticles was approximately 150 {mu}m and depending on the amount of magnetic nanoparticles in the reaction medium Mw of microspheres can be altered. (author)

  16. Volume holographic storage and multiplexing in blends of PMMA and a block methacrylic azopolymer, using 488 nm light pulses in the range of 100 ms to 1 s

    DEFF Research Database (Denmark)

    Forcen, Patricia; Oriol, Luis; Sanchez, Carlos

    2008-01-01

    Blends of polymethylmethacrylate (PMMA) and diblock methacrylic azopolymers have been investigated for holographic storage with short light pulses. Transmission electron microscopy measurements show that the dilution of the block copolymer in PMMA changes the microstructure from a lamellar...... to a spherical morphology. Besides the optical anisotropy induced with linearly polarized 488 nm light is smaller and less stable in the blends than in the block copolymer films. Holographic gratings induced with light pulses of 1 s are not as stable as the ones achieved with writing times of several minutes...... (both in the blend and in the block copolymer) but a final efficiency remains. Up to 20 polarization gratings have been multiplexed, using light pulses of 1 s, 300 ms and 100 ms, in thick (500 mu m) blend films. The equilibrium values of the efficiencies are higher than 10(-5) for all the gratings...

  17. The effect of varying carboxylic-group content in reduced graphene oxides on the anticorrosive properties of PMMA/reduced graphene oxide composites

    Directory of Open Access Journals (Sweden)

    K. C. Chang

    2014-12-01

    Full Text Available We present comparative studies on the effect of varying the carboxylic-group content of thermally reduced graphene oxides (TRGs on the anticorrosive properties of as-prepared poly(methyl methacrylate (PMMA/TRG composite (PTC coatings. TRGs were formed from graphene oxide (GO by thermal exfoliation. The as-prepared TRGs were then characterized using Fourier transform infrared (FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS. Subsequently, the PTC materials were prepared via a UV-curing process and then characterized using FTIR spectroscopy and transmission electron microscopy (TEM. PTC coatings containing TRGs with a higher carboxylic-group content exhibited better corrosion protection of a cold-rolled steel electrode that those with a lower carboxylic-group content. This is because the well-dispersed TRG with a higher carboxylic-group content embedded in the PMMA matrix effectively enhances the oxygen barrier properties of the PTC. This conclusion was supported by gas permeability analysis.

  18. Local Antibiotic Delivery by a Bioabsorbable Gel Is Superior to PMMA Bead Depot in Reducing Infection in an Open Fracture Model

    Science.gov (United States)

    2014-06-01

    fashion, and the animals were recovered, allowed full mobility, food, and water. In the other groups, the appropriate local antibiotic treatment...2. However, concentrations of both antibiotics dropped rapidly within the first 48 hours. Animal Study Bacteria were recovered in all wounds in the...control (no antibiotics received) and antibiotic -PMMA bead group. The group treated with antibiotic gel had significantly fewer animals with bacteria

  19. APPLICATION OF TIME-TEMPERATURE SUPERPOSITION PRINCIPLE TO EVALUATION OF SCATTERING INTENSITY EVOLUTION IN PHASE SEPARATION FOR PMMA/SAN BLENDS

    Institute of Scientific and Technical Information of China (English)

    Mao Peng; Qiang Zheng

    2000-01-01

    Spinodal phase separation behavior of poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN)blends was investigated by the time-resolved small angle light scattering (SALS) technique. It was found that the influence of temperature on the scattering intensity evolution followed the time-temperature superposition principle. The relationship between temperature and the relaxation time of scattering intensity I(t) can be well described by the Williams-Landel-Ferry (WLF) function.

  20. The shape effect of Au particles on random laser action in disordered media of Rh6G dye doped with PMMA polymer

    Science.gov (United States)

    Yin, Jiajia; Feng, Guoying; Zhou, Shouhuan; Zhang, Hong; Wang, Shutong; Zhang, Hua

    2016-10-01

    Random laser actions in a disordered media based on polymethyl methacrylate (PMMA) polymer doped with Rh6G dye and Au nanoparticles have been demonstrated. It was observed that the shape of Au nanoparticles can tune the spectral central position of the random laser action. It was also seen that the shape of Au nanoparticles strongly affects the pump threshold. Comparing nanosphere- and nanorod-based systems, the nanorod-based one exhibited a lower threshold.

  1. Fabrication et caractérisation de polymères micro et nano cellulaires à partir de polymères nanostructurés à base PMMA

    OpenAIRE

    Pinto Sanz, Javier

    2014-01-01

    This dissertation focuses on the production and study of nanocellular foams from PMMA based(poly(methyl methacrylate) materials by CO2 gas dissolution foaming.Due to the novelty of this research field several experimental techniques have been improved or adapted in order to provide valuable information from the systems understudy. Nanostructuration of PMMA-based blends induced by the addition of a block copolymer (MAM, poly(methyl methacrylate)-b-poly(butyl acrylate)-b-poly(methyl methacrylat...

  2. Hydrazone-bearing PMMA-functionalized magnetic nanocubes as pH-responsive drug carriers for remotely targeted cancer therapy in vitro and in vivo.

    Science.gov (United States)

    Ding, Xingwei; Liu, Yun; Li, Jinghua; Luo, Zhong; Hu, Yan; Zhang, Beilu; Liu, Junjie; Zhou, Jun; Cai, Kaiyong

    2014-05-28

    To develop vehicles for efficient chemotherapeutic cancer therapy, we report a remotely triggered drug delivery system based on magnetic nanocubes. The synthesized magnetic nanocubes with average edge length of around 30 nm acted as cores, whereas poly(methyl methacrylate) (PMMA) was employed as an intermediate coating layer. Hydrazide was then tailored onto PMMA both for doxorubicin (DOX) loading and pH responsive drug delivery via the breakage of hydrazine bonds. The successful fabrication of the pH responsive drug carrier was confirmed by transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and magnetic hysteresis loops, respectively. The carrier was stable at neutral environment and doxorubicin released at pH of 5.0. Cell viability assay and confocal laser scanning microscopy observations demonstrated that the loaded DOX could be efficiently released after cellular endocytosis and induced cancer cells apoptosis thereby. More importantly, the carrier could be guided to the tumor tissue site with an external magnetic field and led to efficient tumor inhibition with low side effects, which were reflected by magnetic resonance imaging (MRI), change of tumor size, TUNEL staining, and H&E staining assays, respectively. All results suggest that hydrazide-tailoring PMMA-coated magnetic nanocube would be a promising pH-responsive drug carrier for remotely targeted cancer therapy in vitro and in vivo.

  3. Enhancing the water-resistance stability of CaS:Eu2+,Sm2+phosphor with SiO2-PMMA composite coating

    Institute of Scientific and Technical Information of China (English)

    张杰强; 范艳伟; 陈朝阳; 闫世友; 王军华; 赵鹏君; 郝斌; 盖敏强

    2015-01-01

    This work was aimed at improving the water-resistance stability of CaS:Eu2+,Sm2+phosphor. An organic-inorganic com-posite coating method was adopted in order to obtain ideal phosphor. The phosphor was coated with SiO2 via sol-gel technique and it was also covered by polymethyl methacrylate (PMMA) via dissolution-cohesion technique. Powder X-ray diffraction (XRD) patterns, fluorescence spectroscopy and transmission electron microscopy (TEM) were employed to characterize the phase structures, emission spectrum and surface morphologies, respectively. In addition, the water-resistance stability of the phosphor was tested by soaking the phosphor into deionized water. The results showed that the phase structures remained the same as the uncoated phosphor and the po-sition of the fluorescence peak did not shift after surface treatment. Results showed that the water-resistance stability of the phosphor was improved to some degree. Moreover, the photoluminescence (PL) intensity of the coated phosphors reduced less than 10%of the original phosphors. Though being soaked into deionized water for 50 h, the phosphor coated with 10 wt.%SiO2-10 wt.%PMMA retained 85.9%PL intensity compared to that of the uncoated phosphor. Therefore, it could be concluded that the 10 wt.%SiO2-10 wt.%PMMA composite coating effectively improved the phosphor water resistance and retained its good optical properties.

  4. Two-stage treatment of chronic staphylococcal orthopaedic implant-related infections using vancomycin impregnated PMMA spacer and rifampin containing antibiotic protocol.

    Science.gov (United States)

    Isiklar, Z U; Demirörs, H; Akpinar, S; Tandogan, R N; Alparslan, M

    1999-01-01

    To determine the clinical role of rifampin containing antibiotic combination and modified two-stage exchange arthroplasty with a vancomycin loaded polymethylmethacrylate (PMMA) spacer for the treatment of orthopaedic implant related Staphylococcus epidermidis infections, a prospective study was initiated. A total of 10 patients, with a mean age of 59 years (range: 32 to 78 years) were included in the study. The mean follow up was 23.4 months (range: 16 to 36 months). Six patients had an infected hemiarthroplasty of the hip, three had infected total hip arthroplasty, and one had an infected femoral neck fracture with implant failure and pseudoarthrosis. All had culture-proven Staphylococcus epidermidis infections, six of the isolates were methicillin resistant. Following debridement and implantation of a PMMA spacer, a rifampin-vancomycin antibiotic protocol was initiated until the erythrocyte sedimentation rate and C-reactive protein levels were within normal limits. After reimplantation and discharge from the hospital, oral antibiotics with rifampin-ciprofloxacin were continued for three to six months. At the final follow-up none of the patients had any clinical or laboratory signs of infection. Although this study includes a limited number of patients and relatively short-term follow-up the results indicate that in the presence of orthopaedic implant infection with Staphylococcus epidermidis, modified two-stage exchange arthroplasty using a vancomycin-loaded PMMA spacer and a rifampin-containing antibiotic protocol may be beneficial.

  5. Restored viability and function of dental pulp cells on poly-methylmethacrylate (PMMA)-based dental resin supplemented with N-acetyl cysteine (NAC).

    Science.gov (United States)

    Kojima, N; Yamada, M; Paranjpe, A; Tsukimura, N; Kubo, K; Jewett, A; Ogawa, T

    2008-12-01

    This study examines cytotoxicity of poly-methylmethacrylate (PMMA)-based dental temporary filling resin to dental pulp cells, and the potential amelioration of the toxicity with an anti-oxidant amino-acid, N-acetyl cysteine (NAC). Dental pulp cells extracted from rat maxillary incisors were cultured on the resin material with or without NAC incorporation, or on the polystyrene. The cultures were supplied with osteoblastic media, containing dexamethasone. Forty five percent of cells on the PMMA dental resin were necrotic at 24h after seeding. However, this percentage was reduced to 27% by incorporating NAC in the resin, which was the level equivalent to that in the culture on polystyrene. The culture on the untreated resin was found to be negative for alkaline phosphate (ALP) activity at days 5 and 10 or von Kossa mineralized nodule formation at day 20. In contrast, some areas of the cultures on NAC-incorporated resin substrates were ALP and von Kossa positive. Collagen I and dentin sialoprotein genes were barely expressed in day 7 culture on the untreated resin. However, those genes were expressed in the culture on the resin with NAC. These results suggest that the decreased cell viability and the nearly completely suppressed odontoblast-like cell phenotype of dental pulp cells cultured on PMMA dental resin can be salvaged to a biologically significant degree by the incorporation of NAC in the resin.

  6. Preparation of PLLA/PMMA and PLLA/PS binary blend nanoparticles by incorporation of PLLA in methyl methacrylate or styrene miniemulsion homopolymerization

    Directory of Open Access Journals (Sweden)

    Luana Becker Peres

    2015-02-01

    Full Text Available Miniemulsion homopolymerization reactions of methyl methacrylate (MMA and styrene (STY using poly(L-lactide as co-stabilizer were carried out in order to prepare poly(L-lactide/poly(methyl methacrylate (PLLA/PMMA and poly(L-lactide/polystyrene (PLLA/PS binary blend nanoparticles. The effect of PLLA concentration on methyl methacrylate (MMA and styrene (STY homopolymerization reactions was evaluated. It was found that the incorporation of PLLA resulted on acceleration of MMA and STY homopolymerization reactions and led to a molar mass increase of up to 70% for PS in PLLA/PS blend nanoparticles in relation to those prepared without PLLA, which can be attributed to an increase of reaction loci viscosity (gel effect. PLLA also acted as an efficient co-stabilizer, since it was able to retard diffusional degradation of droplets when no other kind of co-stabilizer was used. Two isolated Tgs were found in both PLLA/PMMA and PLLA/PS blend nanoparticles which can be associated to blend immiscibility. TEM images corroborate these results, suggesting that immiscible PLLA/PMMA and PLLA/PS blend nanoparticles could be formed with two segregated phases and core-shell morphology.

  7. Air-stable solution-processed n-channel organic thin film transistors with polymer-enhanced morphology

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhengran; Shaik, Shoieb; Bi, Sheng; Li, Dawen, E-mail: dawenl@eng.ua.edu [Department of Electrical and Computer Engineering, Center for Materials for Information Technology, The University of Alabama, Tuscaloosa, Alabama 35487 (United States); Chen, Jihua [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2015-05-04

    N,N′-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDIF-CN{sub 2}) is an n-type semiconductor exhibiting high electron mobility and excellent air stability. However, the reported electron mobility based on spin-coated PDIF-CN{sub 2} film is much lower than the value of PDIF-CN{sub 2} single crystals made from vapor phase deposition, indicating significant room for mobility enhancement. In this study, various insulating polymers, including poly(vinyl alcohol), poly(methyl methacrylate) (PMMA), and poly(alpha-methylstyrene) (PαMS), are pre-coated on silicon substrate aiming to enhance the morphology of the PDIF-CN{sub 2} thin film, thereby improving the charge transport and air stability. Atomic force microscopy images reveal that with the pre-deposition of PαMS or PMMA polymers, the morphology of the PDIF-CN{sub 2} polycrystalline films is optimized in semiconducting crystal connectivity, domain size, and surface roughness, which leads to significant improvement of organic thin-film transistor (OTFT) performance. Particularly, an electron mobility of up to 0.55 cm{sup 2}/V s has been achieved from OTFTs based on the PDIF-CN{sub 2} film with the pre-deposition of PαMS polymer.

  8. Investigations on laser printing of microcapacitors using poly (methyl methacrylate) dielectric thin films for organic electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Constantinescu, Catalin, E-mail: constantinescu@lp3.univ-mrs.fr; Rapp, Ludovic, E-mail: rapp@lp3.univ-mrs.fr; Delaporte, Philippe; Alloncle, Anne-Patricia, E-mail: alloncle@lp3.univ-mrs.fr

    2016-06-30

    Graphical abstract: - Highlights: • Laser-induced transfer is used for the printing of multilayered microcapacitors. • The dielectric film is made of PMMA, and the electrodes are made of Ag. • We discuss on the properties of the polymer vs. the LIFT printing. • The structure and electrical properties of the capacitors are emphasized. - Abstract: Thin solid pixels made of Ag/PMMA stacks have been fabricated by laser-induced forward transfer (LIFT), to be tested as thin film microcapacitors in organic electronics applications. The square-shaped laser-printed pixels have a lateral size of ∼350 μm, and the thickness of the dielectric film was varied between 100 and 1500 nm. The pixels were deposited on electrode structures made by LIFT printing of silver nanoparticles ink and paste. Optimal printing conditions led to the fabrication of microcapacitors with typical capacitance in the pF range, tuned by changing the properties of the multilayered structure (e.g. pixel size and/or thickness of the dielectric). Their stability was also investigated over time. We discuss on the morphological and electrical properties of such laser-printed structures, with respect to the impact resistance of the polymer and its suitability for the LIFT process.

  9. On the formation of narrowly polydispersed PMMA by surface initiated polymerization (SIP) from AIBN-coated/intercalated clay nanoparticle platelets.

    Science.gov (United States)

    Fan, Xiaowu; Xia, Chuanjun; Advincula, Rigoberto C

    2005-03-15

    Various free radical surface initiated polymerization (SIP) conditions were investigated on clay nanoparticles coated with monocationic 2,2'-azobisisobutyronitrile (AIBN) type free radical initiators. Interesting differences in the mechanism of polymer nanocomposite product formation and the role of nanoparticle surface bound AIBN initiators were observed on three types of poly(methyl methacrylate) (PMMA) polymerization conditions: bulk, suspension, and solution. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements confirmed the attachment of the initiator on the clay particles without decomposition of the azo group. XRD and transmission electron microscopy (TEM) showed that a well-dispersed structure was accomplished only by bulk and solution SIP. The suspension SIP product consisted of a partially exfoliated structure as shown by XRD and clay particle aggregate formation as shown by TEM. In general, the molecular weights (MWs) of the surface bound polymers were found to be lower than those of the free polymer. Using the same clay loading and initiator concentrations, we observed that relatively higher MW polymers were obtained from suspension and bulk polymerizations in contrast to solution method. However, the most interesting observation is that the surface bound polymers (on all three conditions) showed much narrower polydispersity compared to that of a typical AIBN type free radical polymerization.

  10. Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery.

    Science.gov (United States)

    Chang, Cong; Wei, Hua; Wu, De-Qun; Yang, Bin; Chen, Ni; Cheng, Si-Xue; Zhang, Xian-Zheng; Zhuo, Ren-Xi

    2011-11-28

    Thermo-responsive amphiphilic poly(methyl methacrylate)-b-poly(N-isopropylacrylamide-co-N-acryloxysuccinimide) (PMMA-b-P(NIPAAm-co-NAS)) block copolymer was synthesized by successive RAFT polymerizations. The uncross-linked micelles were facilely prepared by directly dissolving the block copolymer in an aqueous medium, and the shell cross-linked (SCL) micelles were further fabricated by the addition of ethylenediamine as a di-functional cross-linker into the micellar solution. Optical absorption measurements showed that the LCST of uncross-linked and cross-linked micelles was 31.0°C and 40.8°C, respectively. Transmission electron microscopy (TEM) showed that both uncross-linked and cross-linked micelles exhibited well-defined spherical shape in aqueous phase at room temperature, while the SCL micelles were able to retain the spherical shape with relatively smaller dimension even at 40°C due to the cross-linked structure. In vitro drug release study demonstrated a slower and more sustained drug release behavior from the SCL micelles at high temperature as compared with the release profile of uncross-linked micelles, indicating the great potential of SCL micelles developed herein as novel smart carriers for controlled drug release.

  11. Effect of Zn(NO3)2 filler on the dielectric permittivity and electrical modulus of PMMA

    Indian Academy of Sciences (India)

    P Maji; P P Pande; R B Choudhary

    2015-04-01

    Composite films consisting of polymethyl methacrylate (PMMA) and Zn(NO3)2 were developed in the laboratory through the sol casting technique. These films were characterized using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The morphological analysis was carried out by scanning electron microscopy (SEM). These analyses revealed the homogeneous and semi-crystalline behaviour of the films. The dielectric response measurement was conducted in the frequency range from 100 Hz to 5 MHz. The real and imaginary part of the dielectric permittivity decreased with the increase in frequency but increased with temperature. The electrical conductivity measurement showed a plateau-like behaviour in the low-frequency region and dispersion in the high-frequency region. The frequency-dependent electrical modulus obeyed Arrhenius law, and it showed an increase in the dipolar interaction with the temperature due to thermal activation. The activation energy of the film specimen was estimated to be about 0.448 eV. Thus the polymeric composite PMMA–Zn(NO3)2 is one of the appropriate candidate for numerous technical applications such as supercapacitors, high-speed computers and gate dielectric material for organic FETs.

  12. Investigation on the Mechanism and Failure Mode of Laser Transmission Spot Welding Using PMMA Material for the Automotive Industry.

    Science.gov (United States)

    Wang, Xiao; Liu, Baoguang; Liu, Wei; Zhong, Xuejiao; Jiang, Yingjie; Liu, Huixia

    2017-01-01

    To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA) is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s) and type II (pulse frequency and the duration is 5 Hz, 3 s)) to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results.

  13. Morphological Study on Room-Temperature-Cured PMMA-Grafted Natural Rubber-Toughened Epoxy/Layered Silicate Nanocomposite

    Directory of Open Access Journals (Sweden)

    N. Y. Yuhana

    2012-01-01

    Full Text Available A morphological study was conducted on ternary systems containing epoxy, PMMA-grafted natural rubber, and organic chemically modified montmorillonite (Cloisite 30B. Optical microscopy, transmission electron microscopy (TEM, scanning electron microscopy (SEM, energy dispersive X-ray (EDX, and wide-angle X-ray diffraction (WAXD analysis were used. The following four materials were prepared at room temperature: cured unmodified epoxy, cured toughened epoxy, cured unmodified epoxy/Cloisite 30B nanocomposites, and cured toughened epoxy/Cloisite 30B nanocomposites. Mixing process was performed by mechanical stirring. Poly(etheramine was used as the curing agent. The detailed TEM images revealed co-continuous and dispersed spherical rubber in the epoxy-rubber blend, suggesting a new proposed mechanism of phase separation. High-magnification TEM analysis showed good interactions between rubber and Cloisite 30B in the ternary system. Also, it was found that rubber particles could enhance the separation of silicates layers. Both XRD and TEM analyses confirmed that the intercalation of Cloisite 30B was achieved. No distinct exfoliated silicates were observed by TEM. Aggregates of layered silicates (tactoids were observed by SEM and EDX, in addition to TEM at low magnification. EDX analysis confirmed the presence of organic and inorganic elements in the binary and ternary epoxy systems containing Cloisite 30B.

  14. Low Density Nanocellular Polymers Based on PMMA Produced by Gas Dissolution Foaming: Fabrication and Cellular Structure Characterization

    Directory of Open Access Journals (Sweden)

    Judith Martín-de León

    2016-07-01

    Full Text Available This paper describes the processing conditions needed to produce low density nanocellular polymers based on polymethylmethacrylate (PMMA with relative densities between 0.45 and 0.25, cell sizes between 200 and 250 nm and cell densities higher than 1014 cells/cm3. To produce these nanocellular polymers, the foaming parameters of the gas dissolution foaming technique using CO2 as blowing agent have been optimized. Taking into account previous works, the amount of CO2 uptake was maintained constant (31% by weight for all the materials. Foaming parameters were modified between 40 °C and 110 °C for the foaming temperature and from 1 to 5 min for the foaming time. Foaming temperatures in the range of 80 to 100 °C and foaming times of 2 min allow for production of nanocellular polymers with relative densities as low as 0.25. Cellular structure has been studied in-depth to obtain the processing-cellular structure relationship. In addition, it has been proved that the glass transition temperature depends on the cellular structure. This effect is associated with a confinement of the polymer in the cell walls, and is one of the key reasons for the improved properties of nanocellular polymers.

  15. Investigation on the Mechanism and Failure Mode of Laser Transmission Spot Welding Using PMMA Material for the Automotive Industry

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    2017-01-01

    Full Text Available To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s and type II (pulse frequency and the duration is 5 Hz, 3 s to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results.

  16. CO(2)-laser micromachining and back-end processing for rapid production of PMMA-based microfluidic systems.

    Science.gov (United States)

    Klank, Henning; Kutter, Jorg P; Geschke, Oliver

    2002-11-01

    In this article, we focus on the enormous potential of a CO(2)-laser system for rapidly producing polymer microfluidic structures. The dependence was assessed of the depth and width of laser-cut channels on the laser beam power and on the number of passes of the beam along the same channel. In the experiments the laser beam power was varied between 0 and 40 W and the passes were varied in the range of 1 to 7 times. Typical channel depths were between 100 and 300 microm, while the channels were typically 250 microm wide. The narrowest produced channel was 85 microm wide. Several bonding methods for microstructured PMMA [poly(methyl methacrylate)] parts were investigated, such as solvent-assisted glueing, melting, laminating and surface activation using a plasma asher. A solvent-assisted thermal bonding method proved to be the most time-efficient one. Using laser micromachining together with bonding, a three-layer polymer microstructure with included optical fibers was fabricated within two days. The use of CO(2)-laser systems to produce microfluidic systems has not been published before. These systems provide a cost effective alternative to UV-laser systems and they are especially useful in microfluidic prototyping due to the very short cycle time of production.

  17. Linear energy transfer and track pattern recognition of secondary radiation generated in hadron therapy beam in a PMMA target

    Science.gov (United States)

    Opalka, L.; Granja, C.; Hartmann, B.; Jakubek, J.; Jaekel, O.; Martisikova, M.; Pospisil, S.; Solc, J.

    2013-02-01

    Hadron therapy uses ion beams for irradiation of cancerous tissue taking advantage of the highly localized dose deposition in the target tumor. For a correct estimation of dose deposited in tissue surrounding the target it is necessary to consider also the contribution of energetic secondary radiation generated by primary ions. It was already experimentally demonstrated that this contribution can be measured using the semiconductor pixel detector Timepix (256 × 256 pixels with 55 μm pitch) visualizing traces of secondary particles. The resolving power of the detector enables the differentiation of traces of different types of particles. In this work we studied the possibilities of determination of different types of secondary particles in correlation with their flight direction. Such identification allows correct assignment of dose for each type of particle. The distribution of secondary particles was compared to Monte Carlo simulations. Measurements were performed with a PMMA target irradiated with a therapeutic carbon beam at the Heidelberg Ion-Beam Therapy Center (HIT).

  18. Improvement of a block co-polymer (PS-b-PMMA)-masked silicon etch profile using a neutral beam

    Science.gov (United States)

    Yun, Deokhyun; Park, Jinwoo; Kim, Hwasung; Mun, Jeongho; Kim, Sangouk; Kim, Kyongnam; Yeom, Geunyoung

    2016-09-01

    Bottom-up block copolymer (BCP) lithography mediated by self-assembly of polystyrene (PS)/poly-methyl methacrylate (PMMA) is widely used as an alternative patterning method for various deep nanoscale devices, such as optical devices and transistors, replacing conventional top-down photolithography. However, the nanoscale BCP mask features formed on the substrates after direct self-assembly of BCP tend to be easily damaged during exposure to the following plasma processing. In this study, silicon masked with a nanoscale BCP mask (PS) was etched by irradiating with a Cl2/Ar neutral beam in addition to a Cl2/Ar ion beam, and the effect of a Cl2/Ar neutral beam instead of a Cl2/Ar ion beam on damage to the PS mask and the silicon etch characteristics of nanodevices was investigated. The results show that the use of a neutral beam instead of an ion beam decreased degradation of the BCP mask during etching; therefore, a more anisotropic silicon etch profile in addition to improved etch selectivity of silicon compared to the BCP mask was observed. Moreover, by using the neutral beam, the sidewall roughness and sidewall angle also improved due to the decreased surface charge and reduced damage to the nanoscale PS mask resulting from use of a highly directional radical beam instead of a conventional ion-based beam.

  19. A low voltage and small hysteresis C60 thin film transistor*

    Institute of Scientific and Technical Information of China (English)

    Zhou Jianlin; Chen Rengang

    2011-01-01

    Organic thin film transistors with C60 as an n-type semiconductor have been fabricated. A tantalum pentoxide (Ta2O5)/poly-methylmethacrylate (PMMA) double-layer structured gate dielectric was used. The Ta2O5 layer was prepared by using a simple solution-based and economical anodization technique. Our results demonstrate that double gate insulators can combine the advantage of Ta2O5 with high dielectric constant and polymer insulator for a better interface with the organic semiconductor. The performance of the device can be improved obviously with double gate insulators, compared to that obtained by using a single Ta2O5 or PMMA insulator. Then, a good performance n-type OTFT, which can work at 10 V with mobility, threshold voltage and on/off current ratio of,respectively, 0.26 cm2/(V·s), 3.2 V and 8.31 × 104, was obtained. Moreover, such an OTFT shows a negligible “hysteresis effect” contributing to the hydroxyl-free insulator surface.

  20. SEMICONDUCTOR DEVICES Low voltage copper phthalocyanine organic thin film transistors with a polymer layer as the gate insulator

    Science.gov (United States)

    Xueqiang, Liu; Weihong, Bi; Tong, Zhang

    2010-12-01

    Low voltage organic thin film transistors (OTFTs) were created using polymethyl-methacrylate-co g-lyciclyl-methacrylate (PMMA-GMA) as the gate dielectric. The OTFTs performed acceptably at supply voltages of about 10 V. From a densely packed copolymer brush, a leakage current as low as 2 × 10-8 A/cm2 was obtained. From the measured capacitance—insulator frequency characteristics, a dielectric constant in the range 3.9-5.0 was obtained. By controlling the thickness of the gate dielectric, the threshold voltage was reduced from -3.5 to -2.0 V. The copper phthalocyanine (CuPc) based organic thin film transistor could be operated at low voltage and 1.2 × 10-3 cm2/(V·s) mobility.

  1. Investigations on laser printing of microcapacitors using poly (methyl methacrylate) dielectric thin films for organic electronics applications

    Science.gov (United States)

    Constantinescu, Catalin; Rapp, Ludovic; Delaporte, Philippe; Alloncle, Anne-Patricia

    2016-06-01

    Thin solid pixels made of Ag/PMMA stacks have been fabricated by laser-induced forward transfer (LIFT), to be tested as thin film microcapacitors in organic electronics applications. The square-shaped laser-printed pixels have a lateral size of ∼350 μm, and the thickness of the dielectric film was varied between 100 and 1500 nm. The pixels were deposited on electrode structures made by LIFT printing of silver nanoparticles ink and paste. Optimal printing conditions led to the fabrication of microcapacitors with typical capacitance in the pF range, tuned by changing the properties of the multilayered structure (e.g. pixel size and/or thickness of the dielectric). Their stability was also investigated over time. We discuss on the morphological and electrical properties of such laser-printed structures, with respect to the impact resistance of the polymer and its suitability for the LIFT process.

  2. Metal-enhanced fluorescence of mixed coumarin dyes by silver and gold nanoparticles: Towards plasmonic thin-film luminescent solar concentrator

    Energy Technology Data Exchange (ETDEWEB)

    El-Bashir, S.M., E-mail: elbashireg@yahoo.com [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia); Department of Physics Faculty of Science, Benha University (Egypt); Barakat, F.M.; AlSalhi, M.S. [Department of Physics and Astronomy, Science College, King Saud University, Riyadh, KSA (Saudi Arabia)

    2013-11-15

    Poly(methyl methacrylate) (PMMA) nanocomposite films doped with mixed coumarin dyestuffs and noble metal nanoparticles (60 nm silver and 100 nm gold) were prepared by spin coating technique. The effect of silver and gold nanoparticles on the film properties was studied by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–vis absorption and fluorescence spectroscopy measurements. DSC measurements indicated the increase of the glass transition temperature of the films by increasing nanogold concentration, recommending their promising thermal stability towards hot climates. It was found that the fluorescence signals of the mixed coumarin dyes were amplified by 5.4 and 7.15 folds as a result of metal enhanced fluorescence (MEF). The research outcomes offered a potential application of these films in solar energy conversion by plasmonic thin film luminescent solar concentrator (PTLSC). -- Graphical abstract: Plasmonic thin film luminescent solar concentrators. Highlights: • Metal enhanced fluorescence was achieved for mixed coumarin dyes doped in PMMA nanocomposite films. • The amplification of the fluorescence signals is dependent on the concentration of silver and gold nanoparticles. • These films is considered as potential candidates for plasmonic thin film luminescent solar concentrators (PTLSCs)

  3. Photocontrol over the disorder-to-order transition in thin films of polystyrene-block-poly(methyl methacrylate) block copolymers containing photodimerizable anthracene functionality.

    Science.gov (United States)

    Chen, Wei; Wang, Jia-Yu; Zhao, Wei; Li, Le; Wei, Xinyu; Balazs, Anna C; Matyjaszewski, Krzysztof; Russell, Thomas P

    2011-11-02

    Reversible photocontrol over the ordering transition of block copolymers (BCPs) from a disordered state to an ordered state, namely the disorder-to-order transition (DOT), can be used to create long-range ordered nanostructures in self-assembled BCPs over macroscopic distances by photocombing, similar to the classic zone refining used to produce highly pure, large single crystals. Here, we have designed and synthesized an anthracene-functionalized tri-BCP containing deuterated polystyrene (d(8)-PS) and poly(methyl methacrylate) (PMMA) blocks, as well as a short middle block of poly(2-hydroxyethyl methacrylates) (PHEMA) that is randomly functionalized by anthracene. This tri-BCP maintains the order-to-disorder transition-type phase behavior of its parent d(8)-PS-b-PMMA di-BCPs. Under 365 nm UV irradiation, the junction between d(8)-PS and PMMA blocks is photocoupled through the anthracene photodimers, leading to a significant increase in the total molecular weight of the tri-BCP. As a consequence, when the tri-BCP is phase-mixed but close to the boundary of the ordering transition, it undergoes the DOT, as evidenced by small-angle neutron scattering and transmission electron microscopy. The tri-BCP could be reversibly brought through the DOT in thin films by taking advantage of photodimerization and thermal dissociation of anthracene. Currently, anthracene-functionalized d(8)-PS-b-PMMA BCP is one of the most promising candidates for the photocombing process to promote long-range laterally ordered nanostructures over macroscopic distances in a noninvasive manner.

  4. Indium oxide thin film based ammonia gas and ethanol vapour sensor

    Indian Academy of Sciences (India)

    K K Makhija; Arabinda Ray; R M Patel; U B Trivedi; H N Kapse

    2005-02-01

    A sensor for ammonia gas and ethanol vapour has been fabricated using indium oxide thin film as sensing layer and indium tin oxide thin film encapsulated in poly(methyl methacrylate) (PMMA) as a miniature heater. For the fabrication of miniature heater indium tin oxide thin film was grown on special high temperature corning glass substrate by flash evaporation method. Gold was deposited on the film using thermal evaporation technique under high vacuum. The film was then annealed at 700 K for an hour. The thermocouple attached on sensing surface measures the appropriate operating temperature. The thin film gas sensor for ammonia was operated at different concentrations in the temperature range 323–493 K. At 473 K the sensitivity of the sensor was found to be saturate. The detrimental effect of humidity on ammonia sensing is removed by intermittent periodic heating of the sensor at the two temperatures 323K and 448 K, respectively. The indium oxide ethanol vapour sensor operated at fixed concentration of 400 ppm in the temperature range 293–393 K. Above 373 K, the sensor conductance was found to be saturate. With various thicknesses from 150–300 nm of indium oxide sensor there was no variation in the sensitivity measurements of ethanol vapour. The block diagram of circuits for detecting the ammonia gas and ethanol vapour has been included in this paper.

  5. 'Active' Thin Sections

    NARCIS (Netherlands)

    De Rooij, M.R.; Bijen, J.M.J.M.

    1999-01-01

    Optical microscopy using thin sections has become more and more important over the last decade to study concrete. Unfortunately, this technique is not capable of studying actually hydrating cement paste. At Delft University of Technology a new technique has been developed using 'active' thin section

  6. Thin Film & Deposition Systems (Windows)

    Data.gov (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  7. Thin Film & Deposition Systems (Windows)

    Data.gov (United States)

    Federal Laboratory Consortium — Coating Lab: Contains chambers for growing thin film window coatings. Plasma Applications Coating Lab: Contains chambers for growing thin film window coatings. Solar...

  8. Fabrication of the flexible nanogenerator from BTO nanopowders on graphene coated PMMA substrates by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Sankar Ganesh, R. [Department of Physics and Nanotechnology, SRM University, Kattankullathur, Chennai, 603203, Tamil Nadu (India); Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8011 (Japan); Sharma, Sanjeev K., E-mail: sksharma@dongguk.edu [Department of Semiconductor Science, Dongguk University-Seoul, Jung-gu, Seoul, 04620 (Korea, Republic of); Abinnas, N. [Department of Physics and Nanotechnology, SRM University, Kattankullathur, Chennai, 603203, Tamil Nadu (India); Durgadevi, E. [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8011 (Japan); Raji, P. [Department of Physics, Mepco Schlenk Engineering College, Sivakasi, 626 005, Tamil Nadu (India); Ponnusamy, S., E-mail: suruponnus@gmail.com [Department of Physics and Nanotechnology, SRM University, Kattankullathur, Chennai, 603203, Tamil Nadu (India); Muthamizhchelvan, C. [Department of Physics and Nanotechnology, SRM University, Kattankullathur, Chennai, 603203, Tamil Nadu (India); Hayakawa, Y. [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8011 (Japan); Kim, Deuk Young [Department of Semiconductor Science, Dongguk University-Seoul, Jung-gu, Seoul, 04620 (Korea, Republic of)

    2017-05-01

    Nanostructured bismuth titanate (Bi{sub 4}Ti{sub 3}O{sub 12}) or BTO powders were synthesized by the combustion method. The crystalline phase of BTO nanopowders was evaluated from X-ray diffraction (XRD) and further confirmed by selected area electron diffraction (SAED) pattern. The SEM and TEM micrographic images clearly showed the nanosheets like morphology of BTO nanopowder. The EDS spectrum of BTO nanopowder showed the elemental peaks of O, Bi and Ti at 0.53 keV, 2.41 keV and 4.49 keV, respectively. FTIR band peaks were observed at 815 and 595 cm{sup -1} corresponding to the stretching vibrations of Bi-O and Ti-O. The red shift in optical absorption of BTO was observed and the bandgap decreased from 3.18 to 3.08 eV as the calcined temperature increased from 600 to 800 °C. The sandwich structure, called the nanogenerator, Graphene/BTO-PDMS/Graphene (G/BTO/G), was fabricated on graphene coated polymethyl methacrylate (PMMA) substrates, which produced a peak voltage (10 mV) by applying the pressure from human's finger. The switching mechanism of BTO nanosheets was observed to be dependent on the polarity and intrinsic dipole formation. - Highlights: • Bi{sub 4}Ti{sub 3}O{sub 12} (BTO) nanosheets synthesized from a simple combustion method. • SEM & TEM images confirmed the nanosheets structure with a hexagonal shape. • XRD and SAED pattern of BTO nanosheets confirmed the orthorhombic crystal structure. • Flexible G/BTO/G nanogenerator fabricated by sol-gel method. • Peak voltage was observed to be 10 mV by applying pressure from human's finger.

  9. A novel methodology based on contact angle hysteresis approach for surface changes monitoring in model PMMA-Corega Tabs system

    Science.gov (United States)

    Pogorzelski, Stanisław J.; Berezowski, Zdzisław; Rochowski, Paweł; Szurkowski, Janusz

    2012-02-01

    The aim of the paper is to propose a quantitative description of dental surface modifications, resulting from application of Corega and oral cavity liquids, with several surface parameters derived from liquid/solid contact angle measurements. In particular, to predict the long-term effectiveness of denture cleansers in prosthetics, it is necessary to determine surface wettability variations for model dental materials/probe liquid systems related to the contamination effect caused by substances found in the oral cavity. A novel simple low-cost methodology, based on liquid drop contact angle hysteresis CAH approach developed by Chibowski, was adopted to trace solid surface free energy changes in the model PMMA-Corega Tabs interfacial layer. Contact angle and its hysteresis were studied with a sessile drop-inclined plate method in contact with a cleanser (Corega Tabs) and model liquids found in the oral cavity. The apparent solid surface free energy, adsorptive film pressure, work of adhesion and spreading were derived from contact angle hysteresis data for both model solid surfaces (reference) and samples affected by different reactive liquids for a certain time. A time-dependent surface wettability changes of dentures were expressed quantitatively in terms of the corresponding variations of the surface energy parameters which turned out to be unequivocally related to the cleanser exposure time and polarity of the liquids applied to the dental material. The novel methodology appeared to be a useful tool for long term surface characterization of dental materials treated with surfactants-containing liquids capable of forming adhesive layers. The time of optimal use and effectiveness of cleansers are also reflected dynamically in the corresponding variations of the surface wettability parameters. Further studies on a large group of dental surface-probe liquid systems are required to specify the role played by other important factors (liquid polarity, pH and temperature).

  10. Effects of Ti, PMMA, UHMWPE, and Co-Cr wear particles on differentiation and functions of bone marrow stromal cells.

    Science.gov (United States)

    Jiang, Yunpeng; Jia, Tanghong; Gong, Weiming; Wooley, Paul H; Yang, Shang-You

    2013-10-01

    This study investigates the roles of orthopedic biomaterial particles [Ti-alloy, poly(methyl methacrylate) (PMMA), ultrahigh-molecular-weight polyethylene (UHMWPE), Co-Cr alloy] on the differentiation and functions of bone marrow stromal cells (BMSCs). Cells were isolated from femurs of BALB/c mice and cultured in complete osteoblast-induction medium in presence of micron-sized biomaterial particles at various doses. 3-(4,5)-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and lactate dehydrogenase assay were performed for cell proliferation and cytotoxicity. Differentiation and function of osteoblasts were evaluated by alkaline phosphatase (ALP), osteocalcin, RANKL, OSX, and Runx2 expressions. Murine interleukin-1 (IL-1), IL-6, and tumor necrosis factor-α in culture media were determined by enzyme-linked immunosorbent assay. Challenge with low doses of Ti, UHMWPE, or Co-Cr particles markedly promoted the bone marrow cell proliferation while high dose of Co-Cr significantly inhibited cell growth (p UHMWPE particles (0.63 mg/mL) exhibited strong ALP activity, whereas Ti and Co-Cr groups showed minimal effects (p UHMWPE and Ti particles also promoted higher expression of proinflammatory cytokines. Real-time polymerase chain reaction data suggested that cells treated with low dose (0.5 mg/mL) particles resulted in distinctly diminished RANKL expression compared to those exposed to high concentrated (3 mg/mL) particles. In conclusion, various types of wear debris particles behaved differently in the differentiation, maturation, and functions of osteogenic cells; and the particulate debris-interacted BMSCs may play an important role in the pathogenesis and process of the debris-associated aseptic prosthetic loosening.

  11. Preparation and characteristics of flexible all-organic thin-film field-effect transistor

    Institute of Scientific and Technical Information of China (English)

    QIU Yong; HU Yuanchuan; Dong Guifang; WANG Liduo; Xie Junfeng; MA Yaning

    2003-01-01

    All-organic thin-film field-effect transistor was prepared on flexible poly(ethylene-terephthalate) (PET) substrate. Poly(methyl-methacrylate) (PMMA) and pentacene are used as a dielectric layer and a semiconductor layer, respectively. The hole mobility of the transistor can reach 2.10×10-2 cm2/Vs, and the on/off current ratio was larger than 105. The performances of the transistor, when the substrate is cured under different radius, were also measured. It was found that the device performance did not change when the curly direction was vertical to the channel length direction and when the curly direction was parallel to the channel length direction with 3.67 cm curvature radius, the mobility of the device increased by more than 20% and the on/off ratio decreased more than one order.

  12. Biomimetic thin film synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Graff, G.L.; Campbell, A.A.; Gordon, N.R.

    1995-05-01

    The purpose of this program is to develop a new process for forming thin film coatings and to demonstrate that the biomimetic thin film technology developed at PNL is useful for industrial applications. In the biomimetic process, mineral deposition from aqueous solution is controlled by organic functional groups attached to the underlying substrate surface. The coatings process is simple, benign, inexpensive, energy efficient, and particularly suited for temperature sensitive substrate materials (such as polymers). In addition, biomimetic thin films can be deposited uniformly on complex shaped and porous substrates providing a unique capability over more traditional line-of-sight methods.

  13. Thin film device applications

    CERN Document Server

    Kaur, Inderjeet

    1983-01-01

    Two-dimensional materials created ab initio by the process of condensation of atoms, molecules, or ions, called thin films, have unique properties significantly different from the corresponding bulk materials as a result of their physical dimensions, geometry, nonequilibrium microstructure, and metallurgy. Further, these characteristic features of thin films can be drasti­ cally modified and tailored to obtain the desired and required physical characteristics. These features form the basis of development of a host of extraordinary active and passive thin film device applications in the last two decades. On the one extreme, these applications are in the submicron dimensions in such areas as very large scale integration (VLSI), Josephson junction quantum interference devices, magnetic bubbles, and integrated optics. On the other extreme, large-area thin films are being used as selective coatings for solar thermal conversion, solar cells for photovoltaic conver­ sion, and protection and passivating layers. Ind...

  14. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  15. Thin Solid Oxide Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material, at least one metal and a catalyst...... material, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same. The present invention also relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous...... cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material and a catalyst material, wherein the electrolyte material is doper zirconia, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same...

  16. Thin Solid Oxide Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material, at least one metal and a catalyst...... material, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same. The present invention also relates to a thin and in principle unsupported solid oxide cell, comprising at least a porous anode layer, an electrolyte layer and a porous...... cathode layer, wherein the anode layer and the cathode layer comprise an electrolyte material and a catalyst material, wherein the electrolyte material is doper zirconia, and wherein the overall thickness of the thin reversible cell is about 150 [mu]m or less, and to a method for producing same...

  17. Multifunctional thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Brozik, Susan M.; Harper, Jason C.; Polsky, Ronen; Wheeler, David R.; Arango, Dulce C.; Dirk, Shawn M.

    2015-10-13

    A thin film with multiple binding functionality can be prepared on an electrode surface via consecutive electroreduction of two or more aryl-onium salts with different functional groups. This versatile and simple method for forming multifunctional surfaces provides an effective means for immobilization of diverse molecules at close proximities. The multifunctional thin film has applications in bioelectronics, molecular electronics, clinical diagnostics, and chemical and biological sensing.

  18. Valve-less Micropump Development of the Polymer PMMA Material%聚合物PMMA材料的无阀微泵研制

    Institute of Scientific and Technical Information of China (English)

    蒋希赟

    2015-01-01

    The valve-less micro pump is often used to directly control micro pump flow, and it avoids the micro pump failure caused by the instability of the valve. This paper described the method of making a microfluidic devices micro pump with polymer PMMA material, put forward some methods of microfluidic manufacturing process and chose the suitable PMMA micro pump manufacturing method, then conducted the valve-less micro pump production and testing, and made flow rate and back pressure test of the micro pump produced with PMMA material, finally combined the developed valve-less micro pump and the integrated free-flow electrophoresis chip to test the its function effect.%无阀微泵经常被使用是为了直接控制微泵的流量,它避免了阀片的不稳定性引起的微泵失效。文章叙述了以聚合物PMMA为材料来制作微流体器件微泵,给出微流体制作工艺的几种方法并从中选出适合于PMMA微泵制作方法,然后进行无阀微泵制作与测试,并对用PMMA材料制作的微泵进行了流量和背压的测试,最后把所研制的无阀微泵与集成化自由流电泳芯片结合测试其功能效果。

  19. Computerized thermal characterization tool (CT)2 for complete thermodynamic coefficients mapping at the wavelength of 10.6 microm: a PMMA case report.

    Science.gov (United States)

    Canestri, Franco

    2009-08-01

    This paper details a proposed clinical identification tool, the Computerized Thermal Characterization Tool or (CT)(2), designed to precisely quantify and forecast the ablation capabilities of a CO(2) laser beam and to optimize its usage when human tissue is exposed to 10.6 microm wavelength radiation. As seen in other studies by the same author, the correct identification of the optical absorption of polymethylmethacrylate (PMMA) allows isolating other key time-dependent coefficients, all described qualitatively rather than quantitatively in the literature, with better accuracy. Tests on other biological media were performed and reported as potential contribution for minimally invasive surgical procedures. The laser in use was configured in different combinations amongst the following parameters: transverse electromagnetic modes (TEM(22)), output power, exposure times, and focal lengths. Several PMMA blocks (1 cm x 4 cm x 4 cm) were exposed to the continuous wave radiation of three commercially available CO(2) medical laser devices with a TEM(11) beam profile. The data were used in a computerized simulation to test a priori the thermal behavior of biological media exposed to a CO(2) laser beam. Interestingly, this behavior could be reproduced on a variety of biological and nonbiological media. Threshold injury conditions were reached for the myocardium at 786 W/cm(2) per pulse, for the aorta at 519 W/cm(2) per pulse, and for the PMMA samples at 393 W/cm(2) per pulse. These values can be used as reference for both minimally invasive surgery and for transmyocardial laser revascularization protocols, combined with the proposed (CT)(2). Further investigations are needed to completely validate the potential clinical utilization.

  20. Differences in antibacterial activity of PMMA/TiO2/Ag nanocomposite on individual dominant bacterial isolates from packaged drinking water, and their consortium under UVC and dark conditions

    Science.gov (United States)

    Natarajan, Saravanan; Kumari, Jyoti; Lakshmi, D. Shanthana; Mathur, Ankita; Bhuvaneshwari, M.; Parashar, Abhinav; Pulimi, Mrudula; Chandrasekaran, N.; Mukherjee, Amitava

    2016-01-01

    Nanocomposites of polymethyl-methacrylate (PMMA) have gained high attention owing to their extensive applications as antibacterial agents. The antibacterial activities of Ag and TiO2 nanoparticles are well established. This study intended to differentiate the antibacterial activities exhibited by PMMA/TiO2/Ag nanocomposite, towards bacterial consortium and single dominant bacterial isolates from packaged drinking water. A silver nanoparticle dose-dependent decline in cell viability of consortium and individual isolates was compared under UVC and dark conditions to evaluate the antibacterial activity of the nanocomposite. To corroborate with the viability results, oxidative stress & cell permeability was also assessed under similar conditions. Surface characterization of PMMA/TiO2/Ag nanocomposite was performed by FTIR, AFM, and SEM analyses after interaction with the bacteria. The PMMA/TiO2/Ag nanocomposite showed enhanced antibacterial activity against single bacterial isolate compared to the consortium. The outcomes from the study with PMMA/TiO2/Ag nanocomposite necessitate relooking at the test design for assessment of antibacterial effects in real conditions incorporating the impact on the consortium of microorganisms instead of individual strains.

  1. Synthesis of hydroximic acid functionalized PMMA/AM/HOA resin and its adsorbability for Hg2+ and Cd2+%羟肟酸功能化PMMA/AM/HOA的合成及对Hg2+和Cd2+的吸附性能

    Institute of Scientific and Technical Information of China (English)

    孙林; 刘春萍; 马松梅; 孙豪展; 陈秋

    2016-01-01

    用悬浮聚合法合成了甲基丙烯酸甲酯(MMA)与丙烯酰胺(AM)的共聚物PMMA/AM,再经羟胺改性制备了含羟肟酸功能基的改性PMMA/AM/HOA树脂.通过红外光谱(FTIR)和热重分析(TG)对PMMA/AM/HOA树脂的结构和稳定性进行了表征.以PMMA/AM/HOA为吸附剂,考察了温度、吸附时间、pH值和金属离子浓度等条件对Hg2+、Cd2+两种金属离子吸附性能的影响.结果表明,改性树脂对Hg2+、Cd2+具有良好的吸附能力,其实验吸附量分别为0.822和0.384 mmol·g-1.改性树脂对Hg2+和Cd2+的吸附过程符合拟二级动力学方程,25℃时其二级动力学吸附速率常数分别为5.301×10-2和3.582×10-2g·(mmol·min)-1;改性树脂对Hg2+和Cd2+的吸附量随温度的升高有所增大,吸附过程符合Langmuir和Freundlich吸附等温式.

  2. Fabricación y caracterización de espumas poliméricas en base polimetilmetacrilato (PMMA): del rango micro al nanométrico

    OpenAIRE

    Martín Cid, Andrés

    2014-01-01

    Este estudio está enfocado en la producción de espumas microcelulares y nanocelulares a partir de polimetilmetacrilato (PMMA) puro y en el análisis de la estructura y de algunas propiedades físicas de las espumas fabricadas. Estos materiales celulares han sido producidos mediante el proceso de solid state foaming utilizando CO2 como agente espumante físico. Con este propósito, se han producido varias espumas microcelulares y nanocelulares utilizando diferentes presiones entre 10-30 MPa a t...

  3. Design and Fabrication of a PMMA Microfluidic Detection Chip%PMMA微流控检测芯片的设计与制作

    Institute of Scientific and Technical Information of China (English)

    唐飞; 王晓浩; 杨波

    2009-01-01

    设计并制作了一种PMMA(polymethyl methacrylate)材料的微流控检测芯片,将外界气体驱动液体用于实际水样的分析和检测.利用精密加工的方法加工出芯片的整体尺寸为86 mm×60 mm×4.5 mm.采用溶胶-凝胶的改性方法对微通道管路进行亲水处理,正硅酸乙酯的水解缩合生成了一层溶胶-凝胶覆盖在PMMA表面,从而大大提高了亲水性.在室温下对芯片进行键合,溶剂为二氯乙烷和无水乙醇按1:1混合的混合液.该方法避免了微通道的坍塌,有效防止了堵塞.实验证明,芯片接触紧密,且冲击强度能够满足要求.同时,芯片上集成了多个阀.阀膜选用0.5 mm厚的硅胶膜,采用硅橡胶做黏合剂.%A microfluidic detection chip with polymethyl methacrylate(PMMA) was designed and fabricated in this paper to analyze and detect water sample which, as liquid, was driven by external gas. The dimension of the chip is 86 mm×60 mm×4.5 mm, fabricated by the method of precision machining. By a kind of sol-gel method, the hydrolytic condensation reaction of ethyl silicate enables a layer of sol-gel to cover on PMMA surface so that the hydrophilic property in micro tube is improved remarkably. The chip was bonded at room temperature by the solvent bonding method with the solvent of dichloroethane-alcohol mixed in proportion of 1 : 1. Collapse and blockage of the micro tube were avoided, in addition, no leakage was found yet. Experimental results prove the chip's contact compact enough to enable the impact strength to meet the requirement. Meanwhile, several valves are integrated on the chip. Silica gel membrane with 0.5 mm in thickness used for the valve membrane is bonded together with the PMMA using silicone rubber.

  4. ITSTUDIES ON THE EFFECT OF UREA ON THE COMPATIBILITY OF PMMA/PVC MIXTURES IN DMF BY A DILUTE- SOLUTION VISCOMETRY METHOD

    Institute of Scientific and Technical Information of China (English)

    Rajai Baraka; Jamil K.J. Salem; Hani Hilles; Omar Melad

    2002-01-01

    The interaction between poly(methymethacrylate) (PMMA) and poly(vinyl chloride) (PVC) has been studied in dilute urea solutions of dimethylformamide (DMF) at 28℃ using a dilute solution viscometry method. The results show that the polymer mixtures are compatible in DMF solution in the absence of urea. The influence of urea addition on the degree of compatibility of the polymer mixtures has been studied in terms of the compatibility parameters (Abm and A[r]m). It was found that the compatibility of the polymer mixtures is decreased with increasing urea addition, passing through a minimum at 0.5 M urea.

  5. On near-free-surface dynamics of thin polymer films

    Science.gov (United States)

    Qi, Dongping

    In the present studies of four projects we developed several novel techniques to investigate near-free-surface dynamics of thin polymer films. In the first project, we studied the dynamical properties of the first 2-3 nm region of glassy isotactic poly (methyl methacrylate) (i-PMMA) films by means of the nano surface hole relaxation technique. We found that for the measured surface relaxation times there is a strong substrate property dependence, which can propagate into i-PMMA films for a distance of more than 100nm. An unexpected molecular weight (Mw) dependence of the near surface relaxation time is found for thick i-PMMA films, which, together with the finding that the free surface could be assigned a local surface glass transition temperature of ˜40K below bulk T g, indicates a viscous liquid regime while the rest of the underneath bulk part is in the glassy state. In the second project, the nano gold sphere embedding technique was used to study the nearfree-surface dynamics of polystyrene (PS) films within wide temperature and time windows. Three sections of measurements are conducted in this project. In the first section, we studied the Mw dependence of the near-free-surface dynamics of PS films and found that at temperatures above bulk Tg there exists a Mw dependence which can be explained using the Rouse dynamics for melt polymers. However, at a temperature of 16K below bulk T g no w M dependence is discernible, which is in contrast to that for i-PMMA films where even at a temperature of ˜36K below bulk Tg a Mw dependence of the near free surface dynamics is still observed. In the second section of this work, we studied the nano gold sphere embedding behavior within a wide temperature and time window, and for the first time the depth dependence of the near-free-surface dynamics with the nanometer scale resolution was observed. By an embedding-model-free data analysis the results show that when the measurement temperature is above a temperature of ˜378K

  6. Processing and performance of organic insulators as a gate layer in organic thin film transistors fabricated on polyethylene terephthalate substrate

    Indian Academy of Sciences (India)

    Saumen Mandal; Monica Katiyar

    2013-08-01

    Fabrication of organic thin film transistor (OTFT) on flexible substrates is a challenge, because of its low softening temperature, high roughness and flexible nature. Although several organic dielectrics have been used as gate insulator, it is difficult to choose one in absence of a comparative study covering processing of dielectric layer on polyethylene terephthalate (PET), characterization of dielectric property, pentacene film morphology and OTFT characterization. Here, we present the processing and performance of three organic dielectrics, poly(4-vinylphenol) (PVPh), polyvinyl alcohol (PVA) and poly(methylmethacrylate) (PMMA), as a gate layer in pentacene-based organic thin film transistor on PET substrate. We have used thermogravimetric analysis of organic dielectric solution to determine annealing temperature for spin-coated films of these dielectrics. Comparison of the leakage currents for the three dielectrics shows PVA exhibiting lowest leakage (in the voltage range of −30 to +30 V). This is partly because solvent is completely eliminated in the case of PVA as observed by differential thermogravimetric analysis (DTGA). We propose that DTGA can be a useful tool to optimize processing of dielectric layers. From organic thin film transistor point of view, crystal structure, morphology and surface roughness of pentacene film on all the dielectric layers were studied using X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM).We observe pyramidal pentacene on PVPh whereas commonly observed dendritic pentacene on PMMA and PVA surface. Pentacene morphology development is discussed in terms of surface roughness, surface energy and molecular nature of the dielectric layer.

  7. Comment on "Observation of mutual diffusion of macromolecules in PS/PMMA binary films by confocal Raman microscopy" by C. Hu, X. Chen, J. Chen, W. Zhang and M. Q. Zhang, Soft Matter, 2012, 8, 4780.

    Science.gov (United States)

    Tomba, J Pablo

    2016-05-18

    A paper by Hu et al. (Soft Matter, 2012, 8, 4780) reports on the use of confocal Raman microscopy to resolve mutual diffusion between polystyrene (PS) and poly(methyl methacrylate) (PMMA). In-depth optical sectioning is employed to measure the diffusive broadening of the originally planar PS-PMMA interface, from which tracer and mutual diffusion coefficients and values for the PS-PMMA thermodynamic interaction parameter are extracted. Here, a reinterpretation of Hu's data that leads to a completely different scenario is presented, as apparent diffusive broadening can be mostly attributed to optical distortions inherent to the probe methodology. It also explains the lack of consistency of kinetic and thermodynamic parameters obtained by the authors from their diffusion analysis in comparison with earlier published data on this system. Overall, it highlights the importance of carrying out appropriate data analysis when confocal Raman microscopy is applied in dry depth-profiling investigations.

  8. Solid-phase extraction and purification of membrane proteins using a UV-modified PMMA microfluidic bioaffinity μSPE device.

    Science.gov (United States)

    Battle, Katrina N; Jackson, Joshua M; Witek, Małgorzata A; Hupert, Mateusz L; Hunsucker, Sally A; Armistead, Paul M; Soper, Steven A

    2014-03-21

    We present a novel microfluidic solid-phase extraction (μSPE) device for the affinity enrichment of biotinylated membrane proteins from whole cell lysates. The device offers features that address challenges currently associated with the extraction and purification of membrane proteins from whole cell lysates, including the ability to release the enriched membrane protein fraction from the extraction surface so that they are available for downstream processing. The extraction bed was fabricated in PMMA using hot embossing and was comprised of 3600 micropillars. Activation of the PMMA micropillars by UV/O3 treatment permitted generation of surface-confined carboxylic acid groups and the covalent attachment of NeutrAvidin onto the μSPE device surfaces, which was used to affinity select biotinylated MCF-7 membrane proteins directly from whole cell lysates. The inclusion of a disulfide linker within the biotin moiety permitted release of the isolated membrane proteins via DTT incubation. Very low levels (∼20 fmol) of membrane proteins could be isolated and recovered with ∼89% efficiency with a bed capacity of 1.7 pmol. Western blotting indicated no traces of cytosolic proteins in the membrane protein fraction as compared to significant contamination using a commercial detergent-based method. We highlight future avenues for enhanced extraction efficiency and increased dynamic range of the μSPE device using computational simulations of different micropillar geometries to guide future device designs.

  9. Effect of the Scattering Radiation in Air and Two Type of Slap Phantom between PMMA and the ISO Water Phantom for Personal Dosimeters Calibration

    Science.gov (United States)

    Kamwang, N.; Rungseesumran, T.; Saengchantr, D.; Monthonwattana, S.; Pungkun, V.

    2017-06-01

    The calibration of personal dosimeter to determine the quantities of the personal dose equivalent, Hp(d), is required to be placed on a suitable phantom in order to provide a reasonable approximation to the radiation backscattering properties as equivalent as part of body. The dosimeter which is worn on the trunk usually calibrated with slap phantom which recommended in ICRU 47 with dimension of 30 cm (w) x 30 cm (h) x 15 cm (t) PMMA slab phantom to achieve uniformity in calibration procedures, on the other hand the International Organization for Standardization (ISO), ISO 4037-3, proposed the ISO water slap phantom, with PMMA walls, same dimension but different wall thickness (front wall 2.5 mm and other side wall 10 mm thick) and fill with water. However, some laboratories are still calibrating a personal dosimeter in air in term of ambient dose equivalent, H*(d). This research study the effect of the scattering radiation in two type of those slap phantoms and in air, to calibrate two type of OSL (XA and LA) and electronic personal dosimeters. The X-ray and Cs-137 radiation field with the energy range from 33 to 662 keV were used. The results of this study will be discussed.

  10. The effect of di-(-2-ethyl hexyl phthalate (Dehp as plasticizer on the thermal and mechanical properties of pvc/pmma blends

    Directory of Open Access Journals (Sweden)

    Kamira Aouachria

    2014-08-01

    Full Text Available Plasticizers play a key role in the formulation of polymers and in determining their physical properties and processability. This study examines the effect of di(2-ethyl hexylphthalate (DEHP as plasticizer on the thermal and mechanical properties of PVC/PMMA blends. For that purpose, blends of variable composition, from 0 to 100 wt%, were prepared in the presence (15, 30 and 50 wt % and in the absence of di(2-ethyl hexylphthalate. The thermal degradation of the blends was investigated by thermogravimetric analysis (TGA in an atmosphere of synthetic air in the temperature range of 50-550°C. The variation of the mechanical properties, such as tensile behavior, hardness and impact resistance, were investigated for all blend compositions. The effect of the plasticizer on the same properties was considered. The results obtained show that a range of properties can be generated according to the blend compositions. Therefore, the addition of PMMA to the blends stabilized PVC, for the initial thermal degradation, and the addition of the plasticizer caused a decrease of stress at break and Young modulus.

  11. Mixed Convection Blowoff Limits as a Function of Oxygen Concentration and Upward Forced Stretch Rate for Burning Pmma Rods of Various Sizes

    Science.gov (United States)

    Marcum, Jeremy W.; Ferkul, Paul V.; Olson, Sandra L.

    2017-01-01

    Normal gravity flame blowoff limits in an axisymmetric pmma rod geometry in upward axial stagnation flow are compared with microgravity Burning and Suppression of Solids II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (pmma) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18 by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity upward flame spread test method which extrapolates the linear blowoff boundary to the zero stretch limit to resolve microgravity flammability limits, something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

  12. The growth of ubiquitous ZnO rods on PMMA-coated substrate by solution-immersion method at different annealing temperatures

    Science.gov (United States)

    Aadila, A.; Asib, N. A. M.; Afaah, A. N.; Husairi, F. S.; Mohamed, R.; Rusop, M.; Khusaimi, Z.

    2016-07-01

    In this work, solution-immersion method was used to grow ZnO rods on PMMA-coated substrate. For this purpose, 0.15 M of zinc nitrate hexahydrate (Zn(NO3)2.6H2O) and hexamethylenetetramine (C6H12N4) were used to growth of ZnO films at different annealing temperatures (room temperature, 80, 100, 120 and 140 °C). The morphology of the films was investigated by Scanning Electron Microscope (SEM) and optical properties were studied by Ultraviolet (UV-Vis) Spectroscopy. SEM analysis showed ubiquitous growth of ZnO rods that became better aligned and more closely-packed as the annealing temperature increased. As the annealing temperature exceeds 100 °C, the rods tend to merge to adjacent particles and the UV absorption decreased for the sample at higher temperatures (120 °C and 140 °C). Good absorption and better orientation of ZnO was obtained for the sample annealed at 100 °C due to the film possess better distribution and these improved orientation of particles caused the light to be effectively scattered on the sample. Both surface morphology and UV was significantly affected by the change in annealing temperatures thus thermal effect played a dominant role in shaping and improving the orientation of ZnO rods on PMMA-coated and its UV absorption.

  13. Decomposition behavior of PMMA in MIM succession thermal debinding%PMMA在MlM后续热脱脂过程中的分解行为

    Institute of Scientific and Technical Information of China (English)

    李松林; 曲选辉; 李益民; 黄伯云

    2001-01-01

    金属粉末注射成形(MIM)粘结剂中高分子物质的分解和排除是一个较缓慢的过程,对这一过程进行理论研究,有助于指导粘结剂的设计和脱脂过程优化.为此,当Fe-2Ni粉末的注射成形坯经充分溶剂脱脂后,用热重法对坯块中的PMMA的热分解行为进行了理论研究和实验验证.假设进行一级反应,根据各种升温速率的热重计算结果,得到了喂料中PMMA热分解反应速率的理论计算表达式:In(1-α)=1.33×109t·exp(-1 479/T);对厚度为6.37rm的注射坯充分溶剂脱脂后,验证了坯块中PMMA分解速率,发现在350℃和400℃时等温脱脂的速率与理论值较接近,但低于理论值;经过优化,对6.37 mm厚的注射坯,采取5~10℃/min的升温速度升温,可在2 h内完成热脱脂过程.%Thermal degradation of polymer substances in metal injection molding feedstock is a time-consuming step.Theoretical investigation of this process will be helpful for binder design and debinding scheme modification. In this pa-per, feedstock containing polymethyl methacrylate(PMMA) is molded and completely solvent-debinded, and thermal deg-radation of PMMA in the partly debinded part is theoretically calculated and tested by experiments. First, thermogravity(TG) measurement is used to compare degradation of pure PMMA and PMMA in the partly debinded part. PMMA degra-dation rate in the brown sample is obtained out of TG test and one-order reaction hypothesis. The rate can be expressedas: In(1 - α) = 1.33 × 109 t·exp( - 1 479/T). And then, 6.37 mm thick sample is adopted to get the actual debindingtime. It is found that the debinding rates of the samples at 350 ℃ and 400 ℃ are close to the theoretical calculation val-ues. When heating at a rate of 5 ~ 10 ℃/min for the 6.37 mm sample, the debinding process is completed within 2 h.

  14. Thin film ceramic thermocouples

    Science.gov (United States)

    Gregory, Otto (Inventor); Fralick, Gustave (Inventor); Wrbanek, John (Inventor); You, Tao (Inventor)

    2011-01-01

    A thin film ceramic thermocouple (10) having two ceramic thermocouple (12, 14) that are in contact with each other in at least on point to form a junction, and wherein each element was prepared in a different oxygen/nitrogen/argon plasma. Since each element is prepared under different plasma conditions, they have different electrical conductivity and different charge carrier concentration. The thin film thermocouple (10) can be transparent. A versatile ceramic sensor system having an RTD heat flux sensor can be combined with a thermocouple and a strain sensor to yield a multifunctional ceramic sensor array. The transparent ceramic temperature sensor that could ultimately be used for calibration of optical sensors.

  15. Biomimetic thin film deposition

    Science.gov (United States)

    Rieke, P. C.; Campbell, A. A.; Tarasevich, B. J.; Fryxell, G. E.; Bentjen, S. B.

    1991-04-01

    Surfaces derivatized with organic functional groups were used to promote the deposition of thin films of inorganic minerals. These derivatized surfaces were designed to mimic the nucleation proteins that control mineral deposition during formation of bone, shell, and other hard tissues in living organisms. By the use of derivatized substrates control was obtained over the phase of mineral deposited, the orientation of the crystal lattice and the location of deposition. These features are of considerable importance in many technically important thin films, coatings, and composite materials. Methods of derivatizing surfaces are considered and examples of controlled mineral deposition are presented.

  16. Galactic Thin Disk

    NARCIS (Netherlands)

    van der Kruit, P.; Murdin, P.; Murdin, Paul

    2000-01-01

    Of the components of our MILKY WAY GALAXY, the thin disk is the most prominent part to our eyes. It manifests itself as the band of faint light that we see encircling the whole sky. Except for the bulge in the direction of the center of our Galaxy, the stars that make up the Milky Way as we see it

  17. Zapping thin film transistors

    NARCIS (Netherlands)

    Golo-Tosic, N.; Kuper, F.G.; Mouthaan, A.J.

    2002-01-01

    It was expected that hydrogenated amorphous silicon thin film transistors (alpha-Si:H TFTs) behave similarly to crystalline silicon transistors under electrostatic discharge (ESD) stress. It will be disproved in this paper. This knowledge is necessary in the design of the transistors used in a ESD

  18. Thin Lens Ray Tracing.

    Science.gov (United States)

    Gatland, Ian R.

    2002-01-01

    Proposes a ray tracing approach to thin lens analysis based on a vector form of Snell's law for paraxial rays as an alternative to the usual approach in introductory physics courses. The ray tracing approach accommodates skew rays and thus provides a complete analysis. (Author/KHR)

  19. Thin Wall Iron Castings

    Energy Technology Data Exchange (ETDEWEB)

    J.F. Cuttino; D.M. Stefanescu; T.S. Piwonka

    2001-10-31

    Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

  20. Thin supported silica membranes

    NARCIS (Netherlands)

    Zivkovic, Tijana

    2007-01-01

    This thesis discusses several transport-related aspects relevant for the application of thin supported silica membranes for gas separation and nanofiltration. The influence of support geometry on overall membrane performance is investigated. Planar (i.e., flat plate), tubular, and multichannel suppo

  1. Comparison of PMMA, foldable silicone and foldable acrylic hydrophobic intraocular lenses in combined phacoemulsification and trabeculectomy Comparação entre lentes intra-oculares de PMMA, lentes dobráveis de silicone e lentes acrílicas hidrofóbicas dobráveis em cirurgias combinadas de facoemulsificação e trabeculectomia

    Directory of Open Access Journals (Sweden)

    Ernani Serpa Junior

    2005-02-01

    Full Text Available PURPOSE: To compare the postoperative results of phacotrabeculectomy with implantation of PMMA, foldable silicone or foldable hydrofobic acrylic intraocular lens (IOL. SETTING: Glaucoma unit, The Royal Liverpool University Hospital, Liverpool, United Kingdom. METHODS: We studied a total of 124 eyes of three consecutive groups of patients with glaucoma and cataract that underwent phacotrabeculectomy with implantation of a PMMA (30 eyes, a foldable silicone (57 eyes or a foldable acrylic (37 eyes IOL. Postoperative Snellen visual acuity and intraocular pressure (IOP, and early and late complications were assessed. All data were analyzed by means of c² test, Fisher's exact test, ANOVA/MANOVA tests or a combination whenever appropriate. RESULTS: In all three groups the early and late mean postoperative IOPs were significantly lower than the preoperative ones (p25 mmHg and hypotony (IOPOBJETIVO: Comparar os resultados pós-operatórios de facotrabeculectomias com implante de lentes intra-oculares de PMMA, dobráveis de silicone e acrílicas hidrofóbicas dobráveis. MÉTODOS: Estudo comparativo retrospectivo, realizado no Departamento de Glaucoma da "St. Paul's Eye Unit - The Royal Liverpool University Hospital", em Liverpool, Inglaterra, onde foram estudados um total de 124 olhos de três grupos consecutivos de pacientes com glaucoma e catarata que foram submetidos à cirurgia de facotrabeculectomia com implante de lentes intra-oculares (LIO de PMMA (30 olhos, dobráveis de silicone (57 olhos e acrílicas hidrofóbicas dobráveis (37 olhos. Foram registradas a visão e pressão intra-ocular (PIO pré e pós-operatória, assim como as complicações pós-operatórias precoces e tardias. Todos os dados foram analisados utilizando-se o teste c², teste exato de Fisher, teste de ANOVA/MANOVA ou uma combinação deles quando necessário. RESULTADOS: Nos três grupos as PIOs pós-operatórias precoces e tardias foram significativamente inferiores

  2. Buckle Driven Delamination in Thin Hard Film Compliant Substrate Systems

    Directory of Open Access Journals (Sweden)

    Bahr D.F.

    2010-06-01

    Full Text Available Deformation and fracture of thin films on compliant substrates are key factors constraining the performance of emerging flexible substrate devices. [1-3] These systems often contain layers of thin polymer, ceramic and metallic films and stretchable interconnects where differing properties induce high normal and shear stresses. [4] As long as the films remain bonded to the substrates, they may deform far beyond their freestanding form. Once debonded, substrate constraint disappears leading to film failure. [3] Experimentally it is very difficult to measure properties in these systems at sub-micron and nanoscales. Theoretically it is very difficult to determine the contributions from the films, interfaces, and substrates. As a result our understanding of deformation and fracture behavior in compliant substrate systems is limited. This motivated a study of buckle driven delamination of thin hard tungsten films on pure PMMA substrates. The films were sputter deposited to thicknesses of 100 nm, 200 nm, and 400 nm with a residual compressive stress of 1.7 GPa. An aluminum oxide interlayer was added on several samples to alter interfacial composition. Buckles formed spontaneously on the PMMA substrates following film deposition. On films without the aluminum oxide interlayer, an extensive network of small telephone cord buckles formed following deposition, interspersed with regions of larger telephone cord buckles. (Figure 1 On films with an aluminum oxide interlayer, telephone cord buckles formed creating a uniform widely spaced pattern. Through-substrate optical observations revealed matching buckle patterns along the film-substrate interface indicating that delamination occurred for large and small buckles with and without an interlayer. The coexistence of large and small buckles on the same substrate led to two distinct behaviors as shown in Figure 2 where normalized buckle heights are plotted against normalized film stress. The behaviors deviate

  3. Buckle Driven Delamination in Thin Hard Film Compliant Substrate Systems

    Science.gov (United States)

    Moody, N. R.; Reedy, E. D.; Corona, E.; Adams, D. P.; Kennedy, M. S.; Cordill, M. J.; Bahr, D. F.

    2010-06-01

    Deformation and fracture of thin films on compliant substrates are key factors constraining the performance of emerging flexible substrate devices. [1-3] These systems often contain layers of thin polymer, ceramic and metallic films and stretchable interconnects where differing properties induce high normal and shear stresses. [4] As long as the films remain bonded to the substrates, they may deform far beyond their freestanding form. Once debonded, substrate constraint disappears leading to film failure. [3] Experimentally it is very difficult to measure properties in these systems at sub-micron and nanoscales. Theoretically it is very difficult to determine the contributions from the films, interfaces, and substrates. As a result our understanding of deformation and fracture behavior in compliant substrate systems is limited. This motivated a study of buckle driven delamination of thin hard tungsten films on pure PMMA substrates. The films were sputter deposited to thicknesses of 100 nm, 200 nm, and 400 nm with a residual compressive stress of 1.7 GPa. An aluminum oxide interlayer was added on several samples to alter interfacial composition. Buckles formed spontaneously on the PMMA substrates following film deposition. On films without the aluminum oxide interlayer, an extensive network of small telephone cord buckles formed following deposition, interspersed with regions of larger telephone cord buckles. (Figure 1) On films with an aluminum oxide interlayer, telephone cord buckles formed creating a uniform widely spaced pattern. Through-substrate optical observations revealed matching buckle patterns along the film-substrate interface indicating that delamination occurred for large and small buckles with and without an interlayer. The coexistence of large and small buckles on the same substrate led to two distinct behaviors as shown in Figure 2 where normalized buckle heights are plotted against normalized film stress. The behaviors deviate significantly from

  4. Modern Thin-Layer Chromatography.

    Science.gov (United States)

    Poole, Colin F.; Poole, Salwa K.

    1989-01-01

    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  5. Thin film metal-oxides

    CERN Document Server

    Ramanathan, Shriram

    2009-01-01

    Presents an account of the fundamental structure-property relations in oxide thin films. This title discusses the functional properties of thin film oxides in the context of applications in the electronics and renewable energy technologies.

  6. Modern Thin-Layer Chromatography.

    Science.gov (United States)

    Poole, Colin F.; Poole, Salwa K.

    1989-01-01

    Some of the important modern developments of thin-layer chromatography are introduced. Discussed are the theory and instrumentation of thin-layer chromatography including multidimensional and multimodal techniques. Lists 53 references. (CW)

  7. Thin films for material engineering

    Science.gov (United States)

    Wasa, Kiyotaka

    2016-07-01

    Thin films are defined as two-dimensional materials formed by condensing one by one atomic/molecular/ionic species of matter in contrast to bulk three-dimensional sintered ceramics. They are grown through atomic collisional chemical reaction on a substrate surface. Thin film growth processes are fascinating for developing innovative exotic materials. On the basis of my long research on sputtering deposition, this paper firstly describes the kinetic energy effect of sputtered adatoms on thin film growth and discusses on a possibility of room-temperature growth of cubic diamond crystallites and the perovskite thin films of binary compound PbTiO3. Secondly, high-performance sputtered ferroelectric thin films with extraordinary excellent crystallinity compatible with MBE deposited thin films are described in relation to a possible application for thin-film MEMS. Finally, the present thin-film technologies are discussed in terms of a future material science and engineering.

  8. Rare Earth Oxide Thin Films

    CERN Document Server

    Fanciulli, Marco

    2007-01-01

    Thin rare earth (RE) oxide films are emerging materials for microelectronic, nanoelectronic, and spintronic applications. The state-of-the-art of thin film deposition techniques as well as the structural, physical, chemical, and electrical properties of thin RE oxide films and of their interface with semiconducting substrates are discussed. The aim is to identify proper methodologies for the development of RE oxides thin films and to evaluate their effectiveness as innovative materials in different applications.

  9. NMR characterization of thin films

    Science.gov (United States)

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2008-11-25

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  10. 通过RAFT聚合制备经GMA偶联的PMMA/TiO2杂化纳米复合物%Preparation of PMMA/TiO2 hybrid nanocomposites via RAFT process with glycidyl methacrylate as coupling agent

    Institute of Scientific and Technical Information of China (English)

    胡伟; 任冠杰; 张见玲; 郭徐燕; 刘桂廷; 冉蓉

    2011-01-01

    The surface of titania (TiO2) nanoparticles is modified by a functional agent glycidyl methacrylate (GMA) to form GMA modified TiO2 particles. The reversible addition-fragmentation chain transfer ( RAFT) polymerization of methyl methacrylate (MM A) and GMA modified TiO2 is initiated by 2,2'-azobis( isobutyronitrile) (AIBN) in the presence of the RAFT agent S-l-dodecyl-S'-( a,a'-dimethyl-a"-acetic acid)trithiocarbonate (DDACT). PMMA is grafted "through" the surface of the GMA modified TiO2 nanoparticles. The results show that the amount of PMMA grafted onto the surface of TiO2 increases with the polymerization time and the aggregation of TiO2 nanoparticles is greatly reduced.%利用表面修饰法合成了常用单体甲基丙烯酸缩水甘油酯(GMA)修饰的TiO2纳米粒子.以甲基丙烯酸甲酯(MMA)为单体,S-1-十二烷基-S'-(α,α'-二甲基-α"-乙酸)三硫代碳酸酯(DDACT)为RAFT试剂,在纳米TiO2表面进行可逆加成-断裂链转移(RAFT)接枝聚合,PMMA"经表面接枝到(grafting through)"改性后的纳米TiO2表面.结果表明,随聚合时间的增加,纳米TiO2表面接枝聚合物PMMA的量增加,颗粒的团聚得到明显减缓.

  11. Application of optical 3D measurement on thin film buckling to estimate interfacial toughness

    Science.gov (United States)

    Jia, H. K.; Wang, S. B.; Li, L. A.; Wang, Z. Y.; Goudeau, P.

    2014-03-01

    The shape-from-focus (SFF) method has been widely studied as a passive depth recovery and 3D reconstruction method for digital images. An important step in SFF is the calculation of the focus level for different points in an image by using a focus measure. In this work, an image entropy-based focus measure is introduced into the SFF method to measure the 3D buckling morphology of an aluminum film on a polymethylmethacrylate (PMMA) substrate at a micro scale. Spontaneous film wrinkles and telephone-cord wrinkles are investigated after the deposition of a 300 nm thick aluminum film onto the PMMA substrate. Spontaneous buckling is driven by the highly compressive stress generated in the Al film during the deposition process. The interfacial toughness between metal films and substrates is an important parameter for the reliability of the film/substrate system. The height profiles of different sections across the telephone-cord wrinkle can be considered a straight-sided model with uniform width and height or a pinned circular model that has a delamination region characterized by a sequence of connected sectors. Furthermore, the telephone-cord geometry of the thin film can be used to calculate interfacial toughness. The instability of the finite element model is introduced to fit the buckling morphology obtained by SFF. The interfacial toughness is determined to be 0.203 J/m2 at a 70.4° phase angle from the straight-sided model and 0.105 J/m2 at 76.9° from the pinned circular model.

  12. [Spectral emissivity of thin films].

    Science.gov (United States)

    Zhong, D

    2001-02-01

    In this paper, the contribution of multiple reflections in thin film to the spectral emissivity of thin films of low absorption is discussed. The expression of emissivity of thin films derived here is related to the thin film thickness d and the optical constants n(lambda) and k(lambda). It is shown that in the special case d-->infinity the emissivity of thin films is equivalent to that of the bulk material. Realistic numerical and more precise general numerical results for the dependence of the emissivity on d, n(lambda) and k(lambda) are given.

  13. Experimental Research on PMMA POF under Irradiation%PMMA塑料光纤辐照特性的实验研究

    Institute of Scientific and Technical Information of China (English)

    陈秀锦; 李荣玉; 李潮奕; 王帅

    2009-01-01

    理论分析了聚甲基丙烯酸甲酯(PMMA)塑料光纤受辐照后物理与化学性能的变化,并对2组塑料光纤样品进行了辐照前后光谱特性的研究及对比实验.分析了包层掺有PbO及纤芯材料特别提纯的塑料光纤以及一般塑料光纤的耐辐照特性和光谱恢复特性,发现纤芯的纯度及外包层的材料对塑料光纤的耐辐照特性具有很大的影响,这为耐辐照塑料光纤的研制提供了依据.

  14. Fluorescence-based Sensing of 2,4,6-Trinitrotoluene (TNT Using a Multi-channeled Poly(methyl methacrylate (PMMA Microimmunosensor

    Directory of Open Access Journals (Sweden)

    Anne W. Kusterbeck

    2010-01-01

    Full Text Available Fluorescence immunoassays employing monoclonal antibodies directed against the explosive 2,4,6-trinitrotoluene (TNT were conducted in a multi-channel microimmunosensor. The multi-channel microimmunosensor was prepared in poly (methyl methacrylate (PMMA via hot embossing from a brass molding tool. The multi-channeled microfluidic device was sol-gel coated to generate a siloxane surface that provided a scaffold for antibody immobilization. AlexaFluor-cadaverine-trinitrobenzene (AlexaFluor-Cad-TNB was used as the reporter molecule in a displacement immunoassay. The limit of detection was 1-10 ng/mL (ppb with a linear dynamic range that covered three orders of magnitude. In addition, antibody crossreactivity was investigated using hexahydro-1,3,5-triazine (RDX, HMX, 2,4-dinitrotoluene (DNT, 4-nitrotoluene (4-NT and 2-amino-4,6-DNT.

  15. Influence of the Ce:YAG Amount on Structure and Optical Properties of Ce:YAG-PMMA Composites for White LED

    Science.gov (United States)

    Armetta, Francesco; Sibeko, Motshabi A.; Luyt, Adriaan S.; Chillura Martino, Delia F.; Spinella, Alberto; Saladino, Maria Luisa

    2016-09-01

    Ce:YAG-poly(methyl methacrylate) (PMMA) composites were prepared by using a melt compounding method, adding several amounts of Ce:YAG in the range 0.1-5 wt. %. The optical properties of the obtained composites and of the composites combined with a blue LED were measured to investigate the effect of the amount of Ce:YAG on the resulting emitted light in view of possible application in white LED manufacture. An increase in Ce:YAG amount caused an increase in the emission and a shift of 15 nm, influencing the white LED performance. The structure and morphology of the composites were studied. The results show that the interaction between the two components, observed by using solid state NMR experiments, are the responsible for the observed shift.

  16. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  17. Thin film superfluid optomechanics

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sachkou, Yauhen; He, Xin; Bowen, Warwick P

    2016-01-01

    Excitations in superfluid helium represent attractive mechanical degrees of freedom for cavity optomechanics schemes. Here we numerically and analytically investigate the properties of optomechanical resonators formed by thin films of superfluid $^4$He covering micrometer-scale whispering gallery mode cavities. We predict that through proper optimization of the interaction between film and optical field, large optomechanical coupling rates $g_0>2\\pi \\times 100$ kHz and single photon cooperativities $C_0>10$ are achievable. Our analytical model reveals the unconventional behaviour of these thin films, such as thicker and heavier films exhibiting smaller effective mass and larger zero point motion. The optomechanical system outlined here provides access to unusual regimes such as $g_0>\\Omega_M$ and opens the prospect of laser cooling a liquid into its quantum ground state.

  18. Hardness evaluation of PMMA reinforced with two different calcinations temperatures of ZrO2-Al2O3-SiO2 filler system

    Science.gov (United States)

    Hasratiningsih, Z.; Takarini, V.; Cahyanto, A.; Faza, Y.; Asri, L. A. T. W.; Purwasasmita, B. S.

    2017-02-01

    Polymethyl methacrylate (PMMA) is one of the materials used for the temporary crown while making fixed partial dentures. Unfortunately, it has low mechanical properties. This study aim’s to improve PMMA hardness by adding ZrO2-Al2O3-SiO2 filler system in two different calcination temperatures. Thirty-two disc form samples with 8mm diameter x 3mm thickness were made from two category-filler based that had been previously evaluated using Scanning Electron Microscope (SEM). Each category was divided into six groups of three respectively from a controlled and different concentrations of 7(A), 9(B), 11(C), 13(D), and 15(E) weight % of reinforced filler system, then tested with Vickers Hardness Tester. Filler particles that calcined at 550° can increase to 700° consist of fine crystalline and amorphous phases; however, the sample shows the highest hardness about 20,19 VHN even though the increase is only 7,5% compared to control. Meanwhile, the sample that calcined at 700°C exhibiting the highest hardness about 15,66 VHN corresponds to sample D, it has increased 25% compared to the control. This is correlated with microstructure result that has more growth crystalline particles. The results were analyzed by ANOVA which determined were not statistically significantly different (p<0.05). Therefore, it can be concluded that the 13% reinforced ZrO2-Al2O3-SiO2 filler system calcined at 700°C shows the highest hardness increase compare to calcination temperature 550-700°C. Although it is not significantly different.

  19. Thin film processes

    CERN Document Server

    Vossen, John L

    1978-01-01

    Remarkable advances have been made in recent years in the science and technology of thin film processes for deposition and etching. It is the purpose of this book to bring together tutorial reviews of selected filmdeposition and etching processes from a process viewpoint. Emphasis is placed on the practical use of the processes to provide working guidelines for their implementation, a guide to the literature, and an overview of each process.

  20. Thin, Lightweight Solar Cell

    Science.gov (United States)

    Brandhorst, Henry W., Jr.; Weinberg, Irving

    1991-01-01

    Improved design for thin, lightweight solar photovoltaic cells with front contacts reduces degradation of electrical output under exposure to energetic charged particles (protons and electrons). Increases ability of cells to maintain structural integrity under exposure to ultraviolet radiation by eliminating ultraviolet-degradable adhesives used to retain cover glasses. Interdigitated front contacts and front junctions formed on semiconductor substrate. Mating contacts formed on back surface of cover glass. Cover glass and substrate electrostatically bonded together.