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Sample records for membrane thin-film fuel

  1. Scanning transmission X-ray microscopy of nano structured thin film catalysts for proton-exchange-membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Lee, Vincent; Berejnov, Viatcheslav; West, Marcia; Kundu, Sumit; Susac, Darija; Stumper, Jürgen; Atanasoski, Radoslav T.; Debe, Mark; Hitchcock, Adam P.

    2014-10-01

    Scanning transmission X-ray microscopy (STXM) has been applied to characterize nano structured thin film (NSTF) catalysts implemented as electrode materials in proton-exchange-membrane (PEM) fuel cells. STXM is used to study all chemical constituents at various stages in the fabrication process, from the perylene red (PR149) starting material, through the formation of the uncoated perylene whiskers, their coated form with Pt-based catalyst, and toward the NSTF anode fully integrated into the catalyst coated membrane (CCM). CCM samples were examined prior to operational testing and after several different accelerated testing protocols: start-up/shut-down (SU/SD), and reversal tests. It was found that, while the perylene support material is present in the pre-test samples, it was completely absent in the post-test samples. We attribute this loss of perylene material to the presence of cracks in the catalyst combined with intensive hydrogenation processes happening at the anode during operation. Despite the loss of the perylene support, the platinum shells forming the NSTF anode catalyst layer performed well during the tests.

  2. Thin-Film Solid Oxide Fuel Cells

    NASA Technical Reports Server (NTRS)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  3. MEMS-based thin-film fuel cells

    DOEpatents

    Jankowksi, Alan F.; Morse, Jeffrey D.

    2003-10-28

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  4. High performance thin-film composite forward osmosis membrane.

    PubMed

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A; Schiffman, Jessica D; Elimelech, Menachem

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 mum) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m(2-)h(-1), while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution.

  5. Microchannel membrane separation applied to confined thin film desorption

    SciTech Connect

    Thorud, Jonathan D.; Liburdy, James A.; Pence, Deborah V.

    2006-08-15

    The concept of a confined thin film to enhance the desorption process is based on a reduced mass diffusion resistance. A wide thin film is formed into a microchannel by using a porous membrane as one wall of the channel enabling vapor extraction along the flow. Heat added to the channel results in vapor generation and subsequent extraction through the membrane. This experimental study investigates the performance of vapor extraction as a function of confined thin film thickness, pressure difference across the membrane and inlet concentration to the microchannel. In addition, heat added to the system was varied and results are presented in terms of the wall superheat temperature relative to the inlet saturated conditions of the binary fluid. The test section was equipped with a transparent window to observe bubble formation and vapor extraction. Results show that the performance, measured by the vapor release rate, increases for reduced channel thickness, for increased pressure difference across the membrane, and for lower inlet concentration. Results show that lower wall superheat correspond to higher heat transfer coefficients. Trends of Nusselt number and Sherwood number versus both channel Reynolds number and the product of the Reynolds number and Schmidt number are presented. Bubble formation in the channel does not degrade overall performance provided a critical heat flux condition does not occur. (author)

  6. Forward osmosis with a novel thin-film inorganic membrane.

    PubMed

    You, Shijie; Tang, Chuyang; Yu, Chen; Wang, Xiuheng; Zhang, Jinna; Han, Jia; Gan, Yang; Ren, Nanqi

    2013-08-01

    Forward osmosis (FO) represents a new promising membrane technology for liquid separation driven by the osmotic pressure of aqueous solution. Organic polymeric FO membranes are subject to severe internal concentration polarization due to asymmetric membrane structure, and low stability due to inherent chemical composition. To address these limitations, this study focuses on the development of a new kind of thin-film inorganic (TFI) membrane made of microporous silica xerogels immobilized onto a stainless steel mesh (SSM) substrate. The FO performances of the TFI membrane were evaluated upon a lab-scale cell-type FO reactor using deionized water as feed solution and sodium chloride (NaCl) as draw solution. The results demonstrated that the TFI membrane could achieve transmembrane water flux of 60.3 L m(-2) h(-1) driven by 2.0 mol L(-1) NaCl draw solution at ambient temperature. Meanwhile, its specific solute flux, i.e. the solute flux normalized by the water flux (0.19 g L(-1)), was 58.7% lower than that obained for a commercial cellulose triacetate (CTA) membrane (0.46 g L(-1)). The quasi-symmetry thin-film microporous structure of the silica membrane is responsible for low-level internal concentration polarization, and thus enhanced water flux during FO process. Moreover, the TFI membrne demonstrated a substantially improved stability in terms of mechanical strength, and resistance to thermal and chemical stimulation. This study not only provides a new method for fabricating quasi-symmetry thin-film inorganic silica membrane, but also suggests an effective strategy using this alternative membrane to achieve improved FO performances for scale-up applications. PMID:23829428

  7. Numerical and Experimental Dynamic Characteristics of Thin-Film Membranes

    NASA Technical Reports Server (NTRS)

    Young, Leyland G.; Ramanathan, Suresh; Hu, Jia-Zhu; Pai, P. Frank

    2004-01-01

    Presented is a total-Lagrangian displacement-based non-linear finite-element model of thin-film membranes for static and dynamic large-displacement analyses. The membrane theory fully accounts for geometric non-linearities. Fully non-linear static analysis followed by linear modal analysis is performed for an inflated circular cylindrical Kapton membrane tube under different pressures, and for a rectangular membrane under different tension loads at four comers. Finite element results show that shell modes dominate the dynamics of the inflated tube when the inflation pressure is low, and that vibration modes localized along four edges dominate the dynamics of the rectangular membrane. Numerical dynamic characteristics of the two membrane structures were experimentally verified using a Polytec PI PSV-200 scanning laser vibrometer and an EAGLE-500 8-camera motion analysis system.

  8. Automated Lipid Bilayer Membrane Formation Using a Polydimethylsiloxane Thin Film.

    PubMed

    Choi, Sangbaek; Yoon, Sunhee; Ryu, Hyunil; Kim, Sun Min; Jeon, Tae-Joon

    2016-01-01

    An artificial lipid bilayer, or black lipid membrane (BLM), is a powerful tool for studying ion channels and protein interactions, as well as for biosensor applications. However, conventional BLM formation techniques have several drawbacks and they often require specific expertise and laborious processes. In particular, conventional BLMs suffer from low formation success rates and inconsistent membrane formation time. Here, we demonstrate a storable and transportable BLM formation system with controlled thinning-out time and enhanced BLM formation rate by replacing conventionally used films (polytetrafluoroethylene, polyoxymethylene, polystyrene) to polydimethylsiloxane (PDMS). In this experiment, a porous-structured polymer such as PDMS thin film is used. In addition, as opposed to conventionally used solvents with low viscosity, the use of squalene permitted a controlled thinning-out time via slow solvent absorption by PDMS, prolonging membrane lifetime. In addition, by using a mixture of squalene and hexadecane, the freezing point of the lipid solution was increased (~16 °C), in addition, membrane precursors were produced that can be indefinitely stored and readily transported. These membrane precursors have reduced BLM formation time of < 1 hr and achieved a BLM formation rate of ~80%. Moreover, ion channel experiments with gramicidin A demonstrated the feasibility of the membrane system. PMID:27501114

  9. Molecular layer-by-layer assembled thin-film composite membranes for water desalination.

    PubMed

    Gu, Joung-Eun; Lee, Seunghye; Stafford, Christopher M; Lee, Jong Suk; Choi, Wansuk; Kim, Bo-Young; Baek, Kyung-Youl; Chan, Edwin P; Chung, Jun Young; Bang, Joona; Lee, Jung-Hyun

    2013-09-14

    Molecular layer-by-layer (mLbL) assembled thin-film composite membranes fabricated by alternating deposition of reactive monomers on porous supports exhibit both improved salt rejection and enhanced water flux compared to traditional reverse osmosis membranes prepared by interfacial polymerization. Additionally, the well-controlled structures achieved by mLbL deposition further lead to improved antifouling performance.

  10. Novel Organic Membrane-based Thin-film Microsensors for the Determination of Heavy Metal Cations

    PubMed Central

    Arida, Hassan A.; Kloock, Joachim P.; Schöning, Michael J.

    2006-01-01

    A first step towards the fabrication and electrochemical evaluation of thin-film microsensors based on organic PVC membranes for the determination of Hg(II), Cd(II), Pb(II) and Cu(II) ions in solutions has been realised. The membrane-coating mixture used in the preparation of this new type of microsensors is incorporating PVC as supporting matrix, o-nitrophenyloctylether (o-NPOE) as solvent mediator and a recently synthesized Hg[dimethylglyoxime(phene)]2+ and Bis-(4-hydroxyacetophenone)-ethylenediamine as electroactive materials for Hg(II) and Cd(II), respectively. A set of three commercialised ionophores for Cd(II), Pb(II) and Cu(II) has been also used for comparison. Thin-film microsensors based on these membranes showed a Nernstian response of slope (26-30 mV/dec.) for the respective tested cations. The potentiometric response characteristics (linear range, pH range, detection limit and response time) are comparable with those obtained by conventional membranes as well as coated wire electrodes prepared from the same membrane. The realisation of the new organic membrane-based thin-film microsensors overcomes the problem of an insufficient selectivity of solid-state-based thin-film sensors.

  11. Synthesis and Nanofiltration Membrane Performance of Oriented Mesoporous Silica Thin Films on Macroporous Supports.

    PubMed

    Clark Wooten, M Kaitlyn; Koganti, Venkat R; Zhou, Shanshan; Rankin, Stephen E; Knutson, Barbara L

    2016-08-24

    Silica thin films with accessible hexagonal close-packed (HCP) pores have been deposited on macroporous supports to achieve composite nanofiltration membranes. The properties of these pore channels have been characterized through solvent flux and solute diffusion experiments. A chemically neutral surface (provided by a cross-linked layer of P123 copolymer) for silica thin film synthesis on the alumina macroporous support promotes the alignment of HCP channels vertical to the substrate, where the mesopore templating agent is block copolymer P123 (poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)). Vertical pore alignment is achieved for thin films (less than ∼100 nm) on a neutral surface and by sandwiching thicker films (∼240 nm) between two chemically neutral surfaces. Solvent flux through the composite membranes is consistent with accessible 10 nm diameter pores. Size selectivity of the membranes is characterized from the permeability of fluorescently tagged solutes (ranging from 4000 to 70 000 Da), where a size cut off occurs at 69 000 Da for the model protein bovine serum albumin. These permeability studies of the nanofiltration membranes serve to demonstrate solute transport in oriented silica thin film membranes and also highlight their versatility for membrane-based separations. PMID:27479791

  12. Defect-free thin film membranes for H2 separation and isolation.

    SciTech Connect

    Nenoff, Tina Maria; Keller, Jay O.; Welk, Margaret Ellen

    2004-05-01

    There is a great need for robust, defect-free, highly selective molecular sieve (zeolite) thin film membranes for light gas molecule separations in hydrogen fuel production from CH{sub 4} or H{sub 2}O sources. In particular, we are interested in (1) separating and isolating H{sub 2} from H{sub 2}O and CH{sub 4}, CO, CO{sub 2}, O{sub 2}, N{sub 2} gases; (2) water management in PEMs and (3) as a replacement for expensive Pt catalysts needed for PEMs. Current hydrogen separation membranes are based on Pd alloys or on chemically and mechanically unstable organic polymer membranes. The use of molecular sieves brings a stable (chemically and mechanically stable) inorganic matrix to the membrane [1-3]. The crystalline frameworks have 'tunable' pores that are capable of size exclusion separations. The frameworks are made of inorganic oxides (e.g., silicates, aluminosilicates, and phosphates) that bring different charge and electrostatic attraction forces to the separation media. The resultant materials have high separation abilities plus inherent thermal stability over 600 C and chemical stability. Furthermore, the crystallographically defined (<1 {angstrom} deviation) pore sizes and shapes allow for size exclusion of very similarly sized molecules. In contrast, organic polymer membranes are successful based on diffusion separations, not size exclusion. We envision the impact of positive results from this project in the near term with hydrocarbon fuels, and long term with biomass fuels. There is a great need for robust, defect-free, highly selective molecular sieve (zeolite) thin film membranes for light gas molecule separations in hydrogen fuel production from CH{sub 4} or H{sub 2}O sources. They contain an inherent chemical, thermal and mechanical stability not found in conventional membrane materials. Our goal is to utilize those zeolitic qualities in membranes for the separation of light gases, and to eventually partner with industry to commercialize the membranes. To

  13. Laboratory assessment of flexible thin-film membranes as a passive barrier to radon gas diffusion.

    PubMed

    Daoud, W Z; Renken, K J

    2001-05-14

    This paper presents the experimental results of utilizing a flexible thin-film membrane as a passive barrier to radon gas diffusion. Nine commercially available membranes of various compositions and thicknesses were evaluated as retardant to radon gas diffusion. The radon gas concentration ratios across the thin-film membranes alone and in combination with an adjacent concrete sample (effective diffusion coefficient) were measured in a laboratory system with state-of-the-art instrumentation. An 8.89-cm diameter, 10.2-cm thick concrete sample of standard composition (w/c = 0.5 and cement:sand:gravel = 1:2:4) was used to simulate a basement and slab-on-grade foundation typical of Wisconsin. The radon gas transport characteristics of this concrete sample (porosity, permeability and diffusion) are documented. The experimentation has identified two superior flexible thin-film membranes that may be employed as effective barriers to radon gas diffusion. These include: Polyethylene Naphthalate (7.62 x 10(-5) m) and Polyethylene Terephthalate Glycol, PETG (7.62 x 10(-5) and 1.27 x 10(-4) m) which had average diffusion coefficients, D, of 4.10 x 10(-14) and 1.66 x 10(-14) m2 s(-1), respectively. Measurements of the effective membrane/concrete diffusion coefficient yielded a further average reduction in D of 98% for the Polyethylene Naphthalate and 96% for the PETG. Details of the experimental set-ups and procedures are described. The results of this investigation have shown that the application of an effective thin-film membrane adjacent to an intact concrete slab can significantly reduce the diffusion of radon gas entry. Therefore, the employment of a flexible thin-film membrane should be considered as a viable radon reduction technology method for residential new construction.

  14. A novel method to fabricate high permeance, high selectivity thin-film composite membranes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report a thin-film composite (TFC) membrane fabrication method based on transfer of a pre-formed, cured active layer onto a microporous support. This method can be used with supports of relatively high pore size and porosity, thus reducing mass transfer resistance from the support. Ethanol-select...

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  16. A novel thin film solid oxide fuel cell for microscale energy conversion

    SciTech Connect

    Jankowiski, A F; Morse, J D

    1999-05-01

    A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, mainfold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by codeposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting interfacial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thickness on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600--1000 C), thereby rendering this fuel cell system suitable for miniaturization. Scaling towards miniaturization is accomplished by utilizing novel micromaching approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable.

  17. Epitaxial thin films

    DOEpatents

    Hunt, Andrew Tye; Deshpande, Girish; Lin, Wen-Yi; Jan, Tzyy-Jiuan

    2006-04-25

    Epitatial thin films for use as buffer layers for high temperature superconductors, electrolytes in solid oxide fuel cells (SOFC), gas separation membranes or dielectric material in electronic devices, are disclosed. By using CCVD, CACVD or any other suitable deposition process, epitaxial films having pore-free, ideal grain boundaries, and dense structure can be formed. Several different types of materials are disclosed for use as buffer layers in high temperature superconductors. In addition, the use of epitaxial thin films for electrolytes and electrode formation in SOFCs results in densification for pore-free and ideal gain boundary/interface microstructure. Gas separation membranes for the production of oxygen and hydrogen are also disclosed. These semipermeable membranes are formed by high-quality, dense, gas-tight, pinhole free sub-micro scale layers of mixed-conducting oxides on porous ceramic substrates. Epitaxial thin films as dielectric material in capacitors are also taught herein. Capacitors are utilized according to their capacitance values which are dependent on their physical structure and dielectric permittivity. The epitaxial thin films of the current invention form low-loss dielectric layers with extremely high permittivity. This high permittivity allows for the formation of capacitors that can have their capacitance adjusted by applying a DC bias between their electrodes.

  18. Thin-Film Solid Oxide Fuel Cell Based on Doped LaGaO3 Electrolyte

    NASA Astrophysics Data System (ADS)

    Wan, Jen-Hau; Goodenough, John B.

    2003-03-01

    Losses in a solid oxide fuel cell (SOFC) arise from the resistance to O2--ion conduction across the electrolyte and from the rate of reactant dissociative chemisorption and migration across the electrode/electrolyte interfaces. Efforts made to reduce the electrolyte thickness have increased the power density that can be withdrawn from the fuel cell. Whereas a SOFC based on a thin layer of yittria-stablized zirconia (YSZ) as the electrolyte has been under development for several years, a similar thin-electrolyte SOFC with La0.8Sr0.2Ga0.83Mg0.17O2.815 (LSGM) has received little attention. A SOFC with a thin layer of LSGM deposited on a porous YSZ substrate that was subsequently impregnated with Ni has been reported to give a power density of 850 mW/cm2 at 800¢XC with H2 as fuel. In our group, different methods have been used to fabricate a thin LSGM membrane on a composite anode, these methods include screen-printing, colloidal deposition, impregnation, and dry-pressing methods. Because of the reaction between LSGM and a Ni anode during fabrication, a layer of La0.4Ce0.6O1.8 (LDC) must be put between the LSGM electrolyte and a NiO+LDC composite anode. The thin-film SOFC made by screen-printing technique produced an anode-supported fuel cell with a 50 mm thick electrolyte+LDC layer. However because the screen-printing method did not produce an air-tight dense electrolyte membrane, the open-circuit voltage dropped to 0.7V instead of the theoretical 1.1V when running on humid hydrogen as fuel. The power density of this cell reaches 700 mW/cm2 at 850¢XC and 520mW/cm2 at 800¢XC. The dry-pressing method allows co-sintering of anode/electrolyte, which lowers the interfacial overpotentials and guarantees an air-tight, dense electrolyte layer. A SOFC power density of 1400 mW/cm2 at 800¢XC with a 200 mm thick LSGM electrolyte will be compared with the result for a thin-film electrolyte.

  19. Molecular layer-by-layer assembled thin-film composite membranes for water desalination.

    PubMed

    Gu, Joung-Eun; Lee, Seunghye; Stafford, Christopher M; Lee, Jong Suk; Choi, Wansuk; Kim, Bo-Young; Baek, Kyung-Youl; Chan, Edwin P; Chung, Jun Young; Bang, Joona; Lee, Jung-Hyun

    2013-09-14

    Molecular layer-by-layer (mLbL) assembled thin-film composite membranes fabricated by alternating deposition of reactive monomers on porous supports exhibit both improved salt rejection and enhanced water flux compared to traditional reverse osmosis membranes prepared by interfacial polymerization. Additionally, the well-controlled structures achieved by mLbL deposition further lead to improved antifouling performance. PMID:23847127

  20. Nanofiber supported thin-film composite membrane for pressure-retarded osmosis.

    PubMed

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2014-04-01

    Sustainable energy can be harnessed from fluids of differing salinity using a process known as pressure-retarded osmosis (PRO). We address one of the critical challenges of advance PRO by introducing a novel electrospun nanofiber-supported thin-film composite PRO membrane platform. The support was tiered with layers of nanofibers of different diameters to better withstand hydraulic pressure. The membranes successfully withstood an applied hydraulic pressure of 11.5 bar and exhibited performance that would produce an equivalent peak power density near 8.0 W/m(2) under real conditions (using 0.5 M NaCl and deionized water as the draw and feed solutions, respectively). This result shows the immense promise of nanofiber supported thin-film composite membranes for use in PRO.

  1. PEALD YSZ-based bilayer electrolyte for thin film-solid oxide fuel cells.

    PubMed

    Yu, Wonjong; Cho, Gu Young; Hong, Soonwook; Lee, Yeageun; Kim, Young Beom; An, Jihwan; Cha, Suk Won

    2016-10-14

    Yttria-stabilized zirconia (YSZ) thin film electrolyte deposited by plasma enhanced atomic layer deposition (PEALD) was investigated. PEALD YSZ-based bi-layered thin film electrolyte was employed for thin film solid oxide fuel cells on nanoporous anodic aluminum oxide substrates, whose electrochemical performance was compared to the cell with sputtered YSZ-based electrolyte. The cell with PEALD YSZ electrolyte showed higher open circuit voltage (OCV) of 1.0 V and peak power density of 182 mW cm(-2) at 450 °C compared to the one with sputtered YSZ electrolyte(0.88 V(OCV), 70 mW cm(-2)(peak power density)). High OCV and high power density of the cell with PEALD YSZ-based electrolyte is due to the reduction in ohmic and activation losses as well as the gas and electrical current tightness.

  2. PEALD YSZ-based bilayer electrolyte for thin film-solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Yu, Wonjong; Cho, Gu Young; Hong, Soonwook; Lee, Yeageun; Kim, Young Beom; An, Jihwan; Cha, Suk Won

    2016-10-01

    Yttria-stabilized zirconia (YSZ) thin film electrolyte deposited by plasma enhanced atomic layer deposition (PEALD) was investigated. PEALD YSZ-based bi-layered thin film electrolyte was employed for thin film solid oxide fuel cells on nanoporous anodic aluminum oxide substrates, whose electrochemical performance was compared to the cell with sputtered YSZ-based electrolyte. The cell with PEALD YSZ electrolyte showed higher open circuit voltage (OCV) of 1.0 V and peak power density of 182 mW cm-2 at 450 °C compared to the one with sputtered YSZ electrolyte(0.88 V(OCV), 70 mW cm-2(peak power density)). High OCV and high power density of the cell with PEALD YSZ-based electrolyte is due to the reduction in ohmic and activation losses as well as the gas and electrical current tightness.

  3. PEALD YSZ-based bilayer electrolyte for thin film-solid oxide fuel cells.

    PubMed

    Yu, Wonjong; Cho, Gu Young; Hong, Soonwook; Lee, Yeageun; Kim, Young Beom; An, Jihwan; Cha, Suk Won

    2016-10-14

    Yttria-stabilized zirconia (YSZ) thin film electrolyte deposited by plasma enhanced atomic layer deposition (PEALD) was investigated. PEALD YSZ-based bi-layered thin film electrolyte was employed for thin film solid oxide fuel cells on nanoporous anodic aluminum oxide substrates, whose electrochemical performance was compared to the cell with sputtered YSZ-based electrolyte. The cell with PEALD YSZ electrolyte showed higher open circuit voltage (OCV) of 1.0 V and peak power density of 182 mW cm(-2) at 450 °C compared to the one with sputtered YSZ electrolyte(0.88 V(OCV), 70 mW cm(-2)(peak power density)). High OCV and high power density of the cell with PEALD YSZ-based electrolyte is due to the reduction in ohmic and activation losses as well as the gas and electrical current tightness. PMID:27595193

  4. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification.

    PubMed

    Reis, Rackel; Dumée, Ludovic F; Tardy, Blaise L; Dagastine, Raymond; Orbell, John D; Schutz, Jürg A; Duke, Mikel C

    2016-01-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  5. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    PubMed Central

    Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

    2016-01-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties. PMID:27363670

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

    PubMed

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

    2015-07-15

    Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces. PMID:26083007

  7. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    NASA Astrophysics Data System (ADS)

    Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

    2016-07-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  8. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification.

    PubMed

    Reis, Rackel; Dumée, Ludovic F; Tardy, Blaise L; Dagastine, Raymond; Orbell, John D; Schutz, Jürg A; Duke, Mikel C

    2016-01-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties. PMID:27363670

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

    PubMed

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

    2015-07-15

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

  10. A novel thin film solid oxide fuel cell for microscale energy conversion

    SciTech Connect

    Jankowiski, A; Morse, J

    1999-07-21

    A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, manifold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by co-deposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting inter-facial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thicknesses on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600-1000 C), thereby rendering this fuel cell system suitable for miniaturization, Scaling towards miniaturization is accomplished by utilizing novel micromachining approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which are not directly scalable. Methods to synthesize anodes for thin film solid-oxide fuel cells (TFSOFCs) from the electrolyte and a conductive material are developed using photolithographic patterning and physical vapor deposition. The anode layer must enable combination of the reactive gases, be conductive to pass the electric current, and provide mechanical support to the electrolyte and cathode layers. The microstructure and morphology desired for the anode layer should facilitate generation of maximum current density from the fuel cell. For these purposes, the parameters of the

  11. State-of-the-art Thin Film Electrolytes For Solid Oxide Fuel Cells

    SciTech Connect

    Thevuthasan, Suntharampillai; Nandasiri, Manjula I.

    2015-02-19

    State-of-the-Art solid oxide fuel cells (SOFC) are amongst the main candidates for clean energy technology due to their high efficiency, fuel flexibility, low air pollution, and minimal greenhouse gas emission. However, high operational temperature of SOFC is a greater challenge in commercialization these devices for low cost and portable applications. High temperature operation of SOFC degrades its performance with aging, limits the selection of materials for fuel cell components, and increases the fabrication cost. Thus, there have been enormous efforts to improve the properties of existing materials and develop new materials for SOFC components in order to lower the operating temperature of SOFC. Recent advances in thin film technology have also been utilized to develop new materials with improved properties for SOFC. One of the key components in SOFC is the electrolyte and several research groups are working on developing new electrolyte materials. In this chapter, we will discuss the recent advances in thin film SOFC electrolytes. This extensive discussion includes the evolution of doped ceria, doped zirconia, and multilayer hetero-structured thin film electrolytes. The newly developed nanoscale thin films and multi-layer hetero-structures with improved oxygen ionic conductivity will have significant impact on SOFC devices.

  12. Aquatic biofouling prevention by electrically charged nanocomposite polymer thin film membranes.

    PubMed

    de Lannoy, Charles-François; Jassby, David; Gloe, Katie; Gordon, Alexander D; Wiesner, Mark R

    2013-03-19

    Electrically conductive polymer-nanocomposite (ECPNC) tight nanofiltration (NF) thin film membranes were demonstrated to have biofilm-preventing capabilities under extreme bacteria and organic material loadings. A simple route to the creation and application of these polyamide-carbon nanotube thin films is also reported. These thin films were characterized with SEM and TEM as well as FTIR to demonstrate that the carbon nanotubes are embedded within the polyamide and form ester bonds with trimesoyl chloride, one of the monomers of polyamide. These polymer nanocomposite thin film materials boast high electrical conductivity (∼400 S/m), good NaCl rejection (>95%), and high water permeability. To demonstrate these membranes' biofouling capabilities, we designed a cross-flow water filtration vessel with insulated electrical leads connecting the ECPNC membranes to an arbitrary waveform generator. In all experiments, conducted in highly bacterially contaminated LB media, flux tests were run until fluxes decreased by 45 ± 3% over initial flux. Biofilm-induced, nonreversible flux decline was observed in all control experiments and a cross-flow rinse with the feed solution failed to induce flux recovery. In contrast, flux decrease for the ECPNC membranes with an electric potential applied to their surface was only caused by deposition of bacteria rather than bacterial attachment, and flux was fully recoverable following a short rinse with the feed solution and no added cleaning agents. The prevention of biofilm formation on the ECPNC membranes was a long-term effect, did not decrease with use, and was highly reproducible. PMID:23413920

  13. Semipermeable thin-film membranes comprising siloxane, alkoxysilyl and aryloxysilyl oligomers and copolymers

    DOEpatents

    Babcock, W.C.; Friesen, D.T.

    1988-11-01

    Novel semipermeable membranes and thin film composite (TFC) gas separation membranes useful in the separation of oxygen, nitrogen, hydrogen, water vapor, methane, carbon dioxide, hydrogen sulfide, lower hydrocarbons, and other gases are disclosed. The novel semipermeable membranes comprise the polycondensation reaction product of two complementary polyfunctional compounds, each having at least two functional groups that are mutually reactive in a condensation polymerization reaction, and at least one of which is selected from siloxanes, alkoxsilyls and aryloxysilyls. The TFC membrane comprises a microporous polymeric support, the surface of which has the novel semipermeable film formed thereon, preferably by interfacial polymerization.

  14. Semipermeable thin-film membranes comprising siloxane, alkoxysilyl and aryloxysilyl oligomers and copolymers

    DOEpatents

    Babcock, Walter C.; Friesen, Dwayne T.

    1988-01-01

    Novel semiperimeable membranes and thin film composite (TFC) gas separation membranes useful in the separation of oxygen, nitrogen, hydrogen, water vapor, methane, carbon dioxide, hydrogen sulfide, lower hydrocarbons, and other gases are disclosed. The novel semipermeable membranes comprise the polycondensation reaction product of two complementary polyfunctional compounds, each having at least two functional groups that are mutually reactive in a condensation polymerization reaction, and at least one of which is selected from siloxanes, alkoxsilyls and aryloxysilyls. The TFC membrane comprises a microporous polymeric support, the surface of which has the novel semipermeable film formed thereon, preferably by interfacial polymerization.

  15. Separation of Hydrogen Using an Electroless Deposited Thin-Film Palladium-Ceramic Composite Membrane

    SciTech Connect

    Ilias, S.; King, F.G.; Fan, Ting-Fang; Roy, S.

    1996-12-31

    The primary objective of this project was to prepare and characterize a hydrogen permselective palladium-ceramic composite membrane for high temperature gas separations and catalytic membrane reactors. Electroless plating method was used to deposit a thin palladium film on microporous ceramic substrate. The objective of this paper is to discuss the preparation and characterization of a thin-film palladium-ceramic composite membrane for selective separation of hydrogen at elevated temperatures and pressures. In this paper, we also present a model to describe the hydrogen transport through the palladium-ceramic composite membrane in a cocurrent flow configuration.

  16. Simulation of thin film membranes formed by interfacial polymerization.

    PubMed

    Oizerovich-Honig, Rachel; Raim, Vladimir; Srebnik, Simcha

    2010-01-01

    Interfacial polymerization is widely used today for the production of ultrathin films for encapsulation, chemical separations, and desalination. Polyamide films, in particular, are employed in manufacturing of reverse osmosis and nanofiltration membranes. While these materials show excellent salt rejection, they have rather low water permeability, both properties that apparently stem from the rigid cross-linked structure. An increasing amount of experimental research on membranes of different chemistries and membrane characterization suggests the importance of other factors (such as unreacted functional groups and surface roughness) in determining membrane performance. We developed a molecular simulation model to qualitatively study the effects of various synthesis conditions on membrane performance, in terms of its estimated porosity and permeability. The model is of an interfacial aggregation process of two types of functional monomers. Film growth with time and structural characteristics of the final film are compared with predictions of existing theories and experimental observations.

  17. Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.

    PubMed

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2013-02-01

    Engineered osmosis (e.g., forward osmosis, pressure-retarded osmosis, direct osmosis) has emerged as a new platform for applications to water production, sustainable energy, and resource recovery. The lack of an adequately designed membrane has been the major challenge that hinders engineered osmosis (EO) development. In this study, nanotechnology has been integrated with membrane science to build a next generation membrane for engineered osmosis. Specifically, hydrophilic nanofiber, fabricated from different blends of polyacrylonitrile and cellulose acetate via electrospinning, was found to be an effective support for EO thin film composite membranes due to its intrinsically wetted open pore structure with superior interconnectivity. The resulting composite membrane exhibits excellent permselectivity while also showing a reduced resistance to mass transfer that commonly impacts EO processes due to its thin, highly porous nanofiber support layer. Our best membrane exhibited a two to three times enhanced water flux and 90% reduction in salt passage when compared to a standard commercial FO membrane. Furthermore, our membrane exhibited one of the lowest structural parameters reported in the open literature. These results indicate that hydrophilic nanofiber supported thin film composite membranes have the potential to be a next generation membrane for engineered osmosis.

  18. Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.

    PubMed

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2013-02-01

    Engineered osmosis (e.g., forward osmosis, pressure-retarded osmosis, direct osmosis) has emerged as a new platform for applications to water production, sustainable energy, and resource recovery. The lack of an adequately designed membrane has been the major challenge that hinders engineered osmosis (EO) development. In this study, nanotechnology has been integrated with membrane science to build a next generation membrane for engineered osmosis. Specifically, hydrophilic nanofiber, fabricated from different blends of polyacrylonitrile and cellulose acetate via electrospinning, was found to be an effective support for EO thin film composite membranes due to its intrinsically wetted open pore structure with superior interconnectivity. The resulting composite membrane exhibits excellent permselectivity while also showing a reduced resistance to mass transfer that commonly impacts EO processes due to its thin, highly porous nanofiber support layer. Our best membrane exhibited a two to three times enhanced water flux and 90% reduction in salt passage when compared to a standard commercial FO membrane. Furthermore, our membrane exhibited one of the lowest structural parameters reported in the open literature. These results indicate that hydrophilic nanofiber supported thin film composite membranes have the potential to be a next generation membrane for engineered osmosis. PMID:23234259

  19. Resonance-enhanced x-rays in thin films: a structure probe for membranes and surface layers.

    PubMed

    Wang, J; Bedzyk, M J; Caffrey, M

    1992-10-30

    An x-ray resonance effect in an organic thin film on an x-ray reflecting mirror is reported. The resonance effect is the result of interference between reflected and refracted x-rays at the air-organic thin film interface and occurs at incident angles slightly above the critical angle of the film. In excellent agreement with theory, the primary resonant x-ray electric field that is confined in the organic thin film is approximately 20 times as intense as the electric field of the incident beam when measured at a position close to the center of the film. Resonance-enhanced x-rays can be used to characterize the internal structure of Langmuir-Blodgett thin film membranes. This effect may also find use in x-ray-based thin film devices and in the structural analysis of adlayers and surfaces that have thus far proved difficult, if not impossible, to study because of sensitivity limitations.

  20. Deposition of Pd–Ag thin film membranes on ceramic supports for hydrogen purification/separation

    SciTech Connect

    Pereira, A.I.; Pérez, P.; Rodrigues, S.C.; Mendes, A.; Madeira, L.M.

    2015-01-15

    Highlights: • Thin film Pd–Ag membranes have been produced for hydrogen selectivity. • Magnetron sputtering yields Pd–Ag compact films for atomic H diffusion. • The thin film Pd–Ag membranes yielded a selectivity of α (H{sub 2}/N{sub 2}) = 10. - Abstract: Pd–Ag based membranes supported on porous α-Al{sub 2}O{sub 3} (doped with yttria-stabilized zirconia) were studied for hydrogen selective separation. Magnetron sputtering technique was employed for the synthesis of thin film membranes. The hydrogen permeation flux is affected by the membrane columnar structure, which is formed during deposition. From scanning electron microscopy analysis, it was observed that different sputtering deposition pressures lead to distinct columnar structure growth. X-ray diffraction patterns provided evidence of a Pd–Ag solid solution with an average crystallite domain size of 21 nm, whose preferential growth can be altered by the deposition pressure. The gas-permeation results have shown that the Pd–Ag membrane supported on porous α-Al{sub 2}O{sub 3} is selective toward H{sub 2}. For optimized membrane synthesis conditions, the permeance toward N{sub 2} is 0.076 × 10{sup −6} mol m{sup −2} s{sup −1} Pa{sup −1} at room temperature, whereas for a pressure difference of 300 kPa the H{sub 2}-flux is of the order of ca. 0.21 mol m{sup −2} s{sup −1}, which corresponds to a permeance of 0.71 × 10{sup −6} mol m{sup −2} s{sup −1} Pa{sup −1}, yielding a selectivity of α (H{sub 2}/N{sub 2}) = 10. These findings suggest that the membrane has a reasonable capacity to selectively permeate this gas.

  1. A review on polyamide thin film nanocomposite (TFN) membranes: History, applications, challenges and approaches.

    PubMed

    Lau, W J; Gray, Stephen; Matsuura, T; Emadzadeh, D; Chen, J Paul; Ismail, A F

    2015-09-01

    This review focuses on the development of polyamide (PA) thin film nanocomposite (TFN) membranes for various aqueous media-based separation processes such as nanofiltration, reverse osmosis and forward osmosis since the concept of TFN was introduced in year 2007. Although the total number of published TFN articles falls far short of the articles of the well-known thin film composite (TFC) membranes, its growth rate is significant, particularly since 2012. Generally, by incorporating an appropriate amount of nanofiller into a thin selective PA layer of a composite membrane, one could produce TFN membranes with enhanced separation characteristics as compared to the conventional TFC membrane. For certain cases, the resulting TFN membranes demonstrate not only excellent antifouling resistance and/or greater antibacterial effect, but also possibly overcome the trade-off effect between water permeability and solute selectivity. Furthermore, this review attempts to give the readers insights into the difficulties of incorporating inorganic nanomaterials into the organic PA layer whose thickness usually falls in a range of several-hundred nanometers. It is also intended to show new possible approaches to overcome these challenges in TFN membrane fabrication. PMID:26011136

  2. The effective flux through a thin-film composite membrane

    NASA Astrophysics Data System (ADS)

    Bruna, M.; Chapman, S. J.; Ramon, G. Z.

    2015-05-01

    Composite membrane structures, used extensively in separation processes, comprise an ultra-thin selective polymer film cast over a porous support, whose pores partially obstruct transport out of the top film. Here, we model the composite as a finite thickness slab with a periodic array of circular absorbing patches in an otherwise reflective surface and study the effective transport properties of the composite. We obtain an analytical approximation for the effective diffusive flux as a function of the geometrical parameters, namely the film thickness, the support porosity and the pore size. We find a good agreement with full numerical solutions, and that a good effective rate is achievable with a relatively small number of pores.

  3. Reverse osmosis performance of modified polyvinyl alcohol thin-film composite membranes

    SciTech Connect

    Lang, K.; Chowdhury, G.; Matsuura, T.; Sourirajan, S. )

    1994-08-01

    Membrane separation characteristics in the nanofiltration (NF) and reverse osmosis (RO) regions of the filtration spectrum are governed by a complex combination of both steric hindrance and surface force interactions. NF and RO membranes having surface charges show unusual selectivity behavior not predicted on the basis of physical pore size alone. Hence, practical characterizations should employ techniques to gain insight on membrane function. In this work, the separation characteristics of an anionically charged modified polyvinyl alcohol (PVA) thin-film composite membrane under different operating pressures were investigated. A qualitative measurement of the surface force interactions between solutes and membrane polymer was conducted using liquid chromatography technique. An attempt was also made to study the chlorine resistance of the composite membrane.

  4. Synthesis of Pt-Mo-N Thin Film and Catalytic Activity for Fuel Cells

    SciTech Connect

    Miura, Akira; Tague, Michele E.; Gregoire, John M.; Wen, Xiao-Dong; van Dover, R. Bruce; Abruña, Héctor D.; DiSalvo, Francis J.

    2010-05-13

    Pt-Mo-N composition gradient film was synthesized by combining thin-film deposition techniques and subsequent thermal nitridation. A ternary platinum-based nitride, Pt2Mo3N, showed catalytic activities for fuel cell applications and higher electrochemical stability when it was compared with a PtMo alloy with the same Pt:Mo ratio.

  5. 57 Fe Mössbauer probe of spin crossover thin films on a bio-membrane

    NASA Astrophysics Data System (ADS)

    Naik, Anil D.; Garcia, Yann

    2012-03-01

    An illustrious complex [Fe(ptz)6](BF4)2 (ptz = 1-propyl-tetrazole) ( 1) which was produced in the form of submicron crystals and thin film on Allium cepa membrane was probed by 57Fe Mossbauer spectroscopy in order to follow its intrinsic spin crossover. In addition to a weak signal that corresponds to neat SCO compound significant amount of other iron compounds are found that could have morphed from 1 due to specific host-guest interaction on the lipid-bilayer of bio-membrane. Further complimentary information about biogenic role of membrane, was obtained from variable temperature Mossbauer spectroscopy on a ~5% enriched [57Fe(H2O)6](BF4)2 salt on this membrane.

  6. Nanoporous membrane based on block copolymer thin film for protein drug delivery

    NASA Astrophysics Data System (ADS)

    Yang, Seung Yun; Yang, Jeong-A.; Kim, Eung-Sam; Jeon, Gumhye; Oh, Eun Ju; Choi, Kwan Yong; Hahn, Sei Kwang; Kim, Jin Kon

    2010-03-01

    We studied long term and controlled release of protein drugs by using nanoporous membranes with various pore sizes. Nanoporous membrane consists of the separation layer prepared by polystyrene-block-poly(methylmethacrylate) copolymer thin film and conventional microfiltration membrane as a support. We demonstrate a long-term constant in vitro release of bovine serum albumin (BSA)and human growth hormone ) (hGH) without their denaturation up to 2 months. A nearly constant serum concentration of hGH was maintained up to 3 weeks in SD rats. The long-term constant delivery based on this membrane for protein drugs within the therapeutic range can be highly appreciated for the patients with hormone- deficiency.

  7. Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

    PubMed

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes.

  8. Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

    PubMed

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. PMID:23002900

  9. Thin Film Catalyst Layers for Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Witham, C. K.; Chun, W.; Ruiz, R.; Valdez, T. I.; Narayanan, S. R.

    2000-01-01

    One of the primary obstacles to the widespread use of the direct methanol fuel cell (DMFC) is the high cost of the catalyst. Therefore, reducing the catalyst loading well below the current level of 8-12 mg/cm 2 would be important to commercialization. The current methods for preparation of catalyst layers consisting of catalyst, ionomer and sometimes a hydrophobic additive are applied by either painting, spraying, decal transfer or screen printing processes. Sputter deposition is a coating technique widely used in manufacturing and therefore particularly attractive. In this study we have begun to explore sputtering as a method for catalyst deposition. Present experiments focus on Pt-Ru catalyst layers for the anode.

  10. Highly hydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles.

    PubMed

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-09-26

    Thin-film composite polyamide membranes are state-of-the-art materials for membrane-based water purification and desalination processes, which require both high rejection of contaminants and high water permeabilities. However, these membranes are prone to fouling when processing natural waters and wastewaters, because of the inherent surface physicochemical properties of polyamides. The present work demonstrates the fabrication of forward osmosis polyamide membranes with optimized surface properties via facile and scalable functionalization with fine-tuned nanoparticles. Silica nanoparticles are coated with superhydrophilic ligands possessing functional groups that impart stability to the nanoparticles and bind irreversibly to the native carboxyl moieties on the membrane selective layer. The tightly tethered layer of nanoparticles tailors the surface chemistry of the novel composite membrane without altering the morphology or water/solute permeabilities of the membrane selective layer. Surface characterization and interfacial energy analysis confirm that highly hydrophilic and wettable membrane surfaces are successfully attained. Lower intermolecular adhesion forces are measured between the new membrane materials and model organic foulants, indicating the presence of a bound hydration layer at the polyamide membrane surface that creates a barrier for foulant adhesion.

  11. Highly hydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles.

    PubMed

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-09-26

    Thin-film composite polyamide membranes are state-of-the-art materials for membrane-based water purification and desalination processes, which require both high rejection of contaminants and high water permeabilities. However, these membranes are prone to fouling when processing natural waters and wastewaters, because of the inherent surface physicochemical properties of polyamides. The present work demonstrates the fabrication of forward osmosis polyamide membranes with optimized surface properties via facile and scalable functionalization with fine-tuned nanoparticles. Silica nanoparticles are coated with superhydrophilic ligands possessing functional groups that impart stability to the nanoparticles and bind irreversibly to the native carboxyl moieties on the membrane selective layer. The tightly tethered layer of nanoparticles tailors the surface chemistry of the novel composite membrane without altering the morphology or water/solute permeabilities of the membrane selective layer. Surface characterization and interfacial energy analysis confirm that highly hydrophilic and wettable membrane surfaces are successfully attained. Lower intermolecular adhesion forces are measured between the new membrane materials and model organic foulants, indicating the presence of a bound hydration layer at the polyamide membrane surface that creates a barrier for foulant adhesion. PMID:22948042

  12. Biofouling Mitigation in Forward Osmosis Using Graphene Oxide Functionalized Thin-Film Composite Membranes.

    PubMed

    Perreault, François; Jaramillo, Humberto; Xie, Ming; Ude, Mercy; Nghiem, Long D; Elimelech, Menachem

    2016-06-01

    Forward osmosis (FO) is an emerging membrane process with potential applications in the treatment of highly fouling feedwaters. However, biofouling, the adhesion of microorganisms to the membrane and the subsequent formation of biofilms, remains a major limitation since antifouling membrane modifications offer limited protection against biofouling. In this study, we evaluated the use of graphene oxide (GO) for biofouling mitigation in FO. GO functionalization of thin-film composite membranes (GO-TFC) increased the surface hydrophilicity and imparted antimicrobial activity to the membrane without altering its transport properties. After 1 h of contact time, deposition and viability of Pseudomonas aeruginosa cells on GO-TFC were reduced by 36% and 30%, respectively, compared to pristine membranes. When GO-TFC membranes were tested for treatment of an artificial secondary wastewater supplemented with P. aeruginosa, membrane biofouling was reduced by 50% after 24 h of operation. This biofouling resistance is attributed to the reduced accumulation of microbial biomass on GO-TFC compared to pristine membranes. In addition, confocal microscopy demonstrated that cells deposited on the membrane surface are inactivated, resulting in a layer of dead cells on GO-TFC that limit biofilm formation. These findings highlight the potential of GO to be used for biofouling mitigation in FO.

  13. Biofouling Mitigation in Forward Osmosis Using Graphene Oxide Functionalized Thin-Film Composite Membranes.

    PubMed

    Perreault, François; Jaramillo, Humberto; Xie, Ming; Ude, Mercy; Nghiem, Long D; Elimelech, Menachem

    2016-06-01

    Forward osmosis (FO) is an emerging membrane process with potential applications in the treatment of highly fouling feedwaters. However, biofouling, the adhesion of microorganisms to the membrane and the subsequent formation of biofilms, remains a major limitation since antifouling membrane modifications offer limited protection against biofouling. In this study, we evaluated the use of graphene oxide (GO) for biofouling mitigation in FO. GO functionalization of thin-film composite membranes (GO-TFC) increased the surface hydrophilicity and imparted antimicrobial activity to the membrane without altering its transport properties. After 1 h of contact time, deposition and viability of Pseudomonas aeruginosa cells on GO-TFC were reduced by 36% and 30%, respectively, compared to pristine membranes. When GO-TFC membranes were tested for treatment of an artificial secondary wastewater supplemented with P. aeruginosa, membrane biofouling was reduced by 50% after 24 h of operation. This biofouling resistance is attributed to the reduced accumulation of microbial biomass on GO-TFC compared to pristine membranes. In addition, confocal microscopy demonstrated that cells deposited on the membrane surface are inactivated, resulting in a layer of dead cells on GO-TFC that limit biofilm formation. These findings highlight the potential of GO to be used for biofouling mitigation in FO. PMID:27160324

  14. Improving the Performance and Antifouling Properties of Thin-Film Composite Membranes for Water Separation Technologies

    NASA Astrophysics Data System (ADS)

    Tiraferri, Alberto

    Membrane-based water separation processes utilize semi-permeable membranes to retain dissolved solids and contaminants. Deployment of these technologies for desalination and wastewater reuse has the potential to sustainably increase the supply of potable, agricultural, and industrial water. Despite considerable development of semi-permeable membranes in the last decades, several design obstacles hampering their progress have yet to be overcome. Specifically, major membrane improvements are currently sought with respect to their performance and productivity, as well as their resistance to fouling. This dissertation research aims at the advancement of semi-permeable membranes by rational optimization of their design to: (i) understand and improve their transport properties and (ii) reduce fouling by organic molecules and delay biofouling by microorganisms. In particular, thin-film composite polyamide membranes for both reverse osmosis and forward osmosis processes are the main target of the investigation. The structural and physicochemical properties of thin-film composite membranes are both characterized and tailored through implementation of original techniques and novel functionalization protocols. The membrane structure and morphology are rationally modified to enhance the mass transport within the support layer. The influence of fabrication conditions on support layer formation and on its final structure is elucidated. The intricate interrelationship among the performance of the different layers of the composite membrane is highlighted and a new protocol is developed to characterize the transport properties of membranes deployed in forward osmosis processes. Novel approaches to impart targeted properties to the active surface of thin-film composite membranes are also proposed. The functionalization is achieved by exploiting the inherent moieties of the polyamide layer to irreversibly bind nanomaterials with desired properties. An experimental method to determine

  15. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes

    PubMed Central

    Khorshidi, Behnam; Thundat, Thomas; Fleck, Brian A.; Sadrzadeh, Mohtada

    2016-01-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ranging from −20 °C to 50 °C. The physico-chemical and morphological properties of the synthesized membranes were carefully characterized using serval analytical techniques. The results confirmed that the TFC membranes, synthesized at sub-zero temperatures of organic solution, had thinner and smoother PA layer with a greater degree of cross-linking and wettability compared to the PA films prepared at 50 °C. We demonstrated that reducing the temperature of organic solution effectively decreased the thickness of the PA active layer and thus enhanced water permeation through the membranes. The most water permeable membrane was prepared at −20 °C and exhibited nine times higher water flux compared to the membrane synthesized at room temperature. The method proposed in this report can be effectively applied for energy- and cost-efficient development of high performance nanofiltration and reverse osmosis membranes. PMID:26924449

  16. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes

    NASA Astrophysics Data System (ADS)

    Khorshidi, Behnam; Thundat, Thomas; Fleck, Brian A.; Sadrzadeh, Mohtada

    2016-02-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ranging from -20 °C to 50 °C. The physico-chemical and morphological properties of the synthesized membranes were carefully characterized using serval analytical techniques. The results confirmed that the TFC membranes, synthesized at sub-zero temperatures of organic solution, had thinner and smoother PA layer with a greater degree of cross-linking and wettability compared to the PA films prepared at 50 °C. We demonstrated that reducing the temperature of organic solution effectively decreased the thickness of the PA active layer and thus enhanced water permeation through the membranes. The most water permeable membrane was prepared at -20 °C and exhibited nine times higher water flux compared to the membrane synthesized at room temperature. The method proposed in this report can be effectively applied for energy- and cost-efficient development of high performance nanofiltration and reverse osmosis membranes.

  17. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes

    NASA Astrophysics Data System (ADS)

    Khorshidi, Behnam; Thundat, Thomas; Fleck, Brian A.; Sadrzadeh, Mohtada

    2016-02-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ranging from ‑20 °C to 50 °C. The physico-chemical and morphological properties of the synthesized membranes were carefully characterized using serval analytical techniques. The results confirmed that the TFC membranes, synthesized at sub-zero temperatures of organic solution, had thinner and smoother PA layer with a greater degree of cross-linking and wettability compared to the PA films prepared at 50 °C. We demonstrated that reducing the temperature of organic solution effectively decreased the thickness of the PA active layer and thus enhanced water permeation through the membranes. The most water permeable membrane was prepared at ‑20 °C and exhibited nine times higher water flux compared to the membrane synthesized at room temperature. The method proposed in this report can be effectively applied for energy- and cost-efficient development of high performance nanofiltration and reverse osmosis membranes.

  18. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes.

    PubMed

    Khorshidi, Behnam; Thundat, Thomas; Fleck, Brian A; Sadrzadeh, Mohtada

    2016-01-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ranging from -20 °C to 50 °C. The physico-chemical and morphological properties of the synthesized membranes were carefully characterized using serval analytical techniques. The results confirmed that the TFC membranes, synthesized at sub-zero temperatures of organic solution, had thinner and smoother PA layer with a greater degree of cross-linking and wettability compared to the PA films prepared at 50 °C. We demonstrated that reducing the temperature of organic solution effectively decreased the thickness of the PA active layer and thus enhanced water permeation through the membranes. The most water permeable membrane was prepared at -20 °C and exhibited nine times higher water flux compared to the membrane synthesized at room temperature. The method proposed in this report can be effectively applied for energy- and cost-efficient development of high performance nanofiltration and reverse osmosis membranes. PMID:26924449

  19. Surface functionalization of thin-film composite membranes with copper nanoparticles for antimicrobial surface properties.

    PubMed

    Ben-Sasson, Moshe; Zodrow, Katherine R; Genggeng, Qi; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2014-01-01

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed.

  20. Surface functionalization of thin-film composite membranes with copper nanoparticles for antimicrobial surface properties.

    PubMed

    Ben-Sasson, Moshe; Zodrow, Katherine R; Genggeng, Qi; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2014-01-01

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. PMID:24308843

  1. Thin film composite polyamide membrane parameters estimation for phenol-water system by reverse osmosis

    SciTech Connect

    Murthy, Z.V.P.; Gupta, S.K.

    1998-12-01

    A commercial thin film composite polyamide reverse osmosis membrane is used to separate an aqueous phenol-water binary system. The separation data are analyzed using a combined film theory-solution-diffusion (CFSD) model and a combined film theory-Spiegler-Kedem (CFSK) model. In the present investigation a new phenomenon is observed: there exists a maximum in the rejection when it is plotted against the product flux through the membrane. This behavior is explained for both models. An equation for J{sub v,min}, which is the value of the product flux J{sub v} at which the rejection reaches a maximum, is derived from both models. Although the parameters for both models are consistent over the range of operating conditions, the CFSK model is more accurate for the phenol-water system.

  2. Elements Provide a Clue: Nanoscale Characterization of Thin-Film Composite Polyamide Membranes.

    PubMed

    Lu, Xinglin; Nejati, Siamak; Choo, Youngwoo; Osuji, Chinedum O; Ma, Jun; Elimelech, Menachem

    2015-08-12

    In this study, we exploit the nitrogen-sulfur elemental contrast of thin-film composite (TFC) polyamide membranes and present, for the first time, the application of two elemental analysis techniques, scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy (STEM-EDX) and X-ray photoelectron spectroscopy (XPS) C60+ ion-beam sputtering, to elucidate the nanoscale structure and chemical composition of the polyamide-polysulfone interface. Although STEM-EDX elemental mapping depicts the presence of a dense polyamide layer at the interface, it is incapable of resolving the elemental contrast at nanoscale resolution at the interfacial zone. Depth-resolved XPS C60+ ion-beam sputtering enabled nanoscale characterization of the polyamide-polysulfone interface and revealed the presence of a heterogeneous layer that contains both polyamide and polysulfone signatures. Our results have important implications for future studies to elucidate the structure-property-performance relationship of TFC membranes. PMID:26213850

  3. Layered conductive polymer on nylon membrane templates for high performance, thin-film supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Shi, HaoTian Harvey; Naguib, Hani E.

    2016-04-01

    Flexible Thin-film Electrochemical Capacitors (ECs) are emerging technology that plays an important role as energy supply for various electronics system for both present era and the future. Intrinsically conductive polymers (ICPs) are promising pseudo-capacitive materials as they feature both good electrical conductivity and high specific capacitance. This study focuses on the construction and characterization of ultra-high surface area porous electrodes based on coating of nano-sized conductive polymer materials on nylon membrane templates. Herein, a novel nano-engineered electrode material based on nylon membranes was presented, which allows the creation of super-capacitor devices that is capable of delivering competitive performance, while maintaining desirable mechanical characteristics. With the formation of a highly conductive network with the polyaniline nano-layer, the electrical conductivity was also increased dramatically to facilitate the charge transfer process. Cyclic voltammetry and specific capacitance results showed promising application of this type of composite materials for future smart textile applications.

  4. Anti-biofouling Sulfobetaine Polymer Thin Films on Silicon and Silicon Nanopore Membranes.

    PubMed

    Li, Lingyan; Marchant, Roger E; Dubnisheva, Anna; Roy, Shuvo; Fissell, William H

    2011-01-01

    Silicon nanopore membranes (SNM) with monodisperse pore size distributions have potential applications in bioartificial kidneys. A protein resistant thin film coating on the SNM is required to minimize biofouling and, hence, enhance the performance efficiency of SNM. In this work, a zwitterionic polymer, poly(sulfobetaine methacrylate) (polySBMA), was used to coat silicon and SNM substrates via a surface initiated atom transfer radical polymerization method. The polySBMA-coated surfaces were characterized using contact angle goniometry, X-ray photoelectron spectroscopy (XPS), ellipsometry and scanning electron microscopy (SEM). Resistance of the coatings to protein fouling was examined by measurement of fibrinogen adsorption from fibrinogen solution and human plasma on coated silicon surfaces. Results showed that the polySBMA coating suppresses non-specific adsorption of fibrinogen. The protein-repellent property of polySBMA thin film coating is comparable to that of PEG-based coatings. Analysis of the surfaces by XPS indicated that the films remained stable when stored under physiologic conditions over a 4-week period. PMID:20546677

  5. Sustainable Antibiofouling Properties of Thin Film Composite Forward Osmosis Membrane with Rechargeable Silver Nanoparticles Loading.

    PubMed

    Liu, Zhongyun; Hu, Yunxia

    2016-08-24

    Microbial attachment and biofilm formation on filtration membrane can greatly compromise its flux and separation efficiency. Here, a simple and facile approach has been developed to in situ generate silver nanoparticles (Ag NPs) on the thin film composite forward osmosis (TFC FO) membrane for sustainable antibiofouling performances. Mussel-inspired dopamine chemistry was applied to grow polydopamine coating on both surfaces of FO membranes, followed by the generation of Ag NPs upon a simple dip coating in silver nitrate aqueous solution. Furthermore, the Ag NPs deposited membranes had a long-term silver release profile with rechargability for multiple times upon their depletion, and exhibited strong sustainable bactericidal efficacy against Gram-negative bacteria and Gram-positive bacteria. The Ag NPs had a controllable effect on the membrane performances including the water flux and reverse salt flux in the FO test mode. Our practicable antibacterial strategy may apply to other types of filtration membranes with diverse material surfaces and may pave a new way to achieve the sustainable membrane antibiofouling performance on a large scale.

  6. Sustainable Antibiofouling Properties of Thin Film Composite Forward Osmosis Membrane with Rechargeable Silver Nanoparticles Loading.

    PubMed

    Liu, Zhongyun; Hu, Yunxia

    2016-08-24

    Microbial attachment and biofilm formation on filtration membrane can greatly compromise its flux and separation efficiency. Here, a simple and facile approach has been developed to in situ generate silver nanoparticles (Ag NPs) on the thin film composite forward osmosis (TFC FO) membrane for sustainable antibiofouling performances. Mussel-inspired dopamine chemistry was applied to grow polydopamine coating on both surfaces of FO membranes, followed by the generation of Ag NPs upon a simple dip coating in silver nitrate aqueous solution. Furthermore, the Ag NPs deposited membranes had a long-term silver release profile with rechargability for multiple times upon their depletion, and exhibited strong sustainable bactericidal efficacy against Gram-negative bacteria and Gram-positive bacteria. The Ag NPs had a controllable effect on the membrane performances including the water flux and reverse salt flux in the FO test mode. Our practicable antibacterial strategy may apply to other types of filtration membranes with diverse material surfaces and may pave a new way to achieve the sustainable membrane antibiofouling performance on a large scale. PMID:27467542

  7. Solvent resistant thin film composite nanofiltration membrane: Characterization and permeation study

    NASA Astrophysics Data System (ADS)

    Minhas, Fozia T.; Memon, Shahabuddin; Bhanger, M. I.; Iqbal, Nadeem; Mujahid, M.

    2013-10-01

    The present investigation reports the fabrication of thin film composite nanofiltration (TFC-NF) membranes using interfacial polymerization technique for desalination. Ethylene diamine (EDA) and terephthaloyl chloride (TPC) were employed as aqueous and organic phase monomers, respectively to develop polyamide thin layer on the surface of Celgard 2400. The prepared membranes were characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The molecular weight cutoff of TFC-NF membranes was estimated to be below 342 Da using dextrose, sucrose and raffinose solutions. A low cost dead end NF Cell was designed and manufactured domestically to conduct permeation experiments. The effect of different reaction conditions including concentration of monomers, residence time in each monomer and curing temperature on the membrane performance (water flux and MgCl2 rejection) was also studied. The water flux was augmented linearly at higher applied pressure while MgCl2 rejection was remained constant. The obtained water flux and MgCl2 rejection were measured 33 L/m2 h and 90%, respectively at 7 bar applied pressure. Beside this, membrane stability was analyzed, which confirmed the excellent constancy of ethanol and n-hexane fluxes even after an extended period. Hagen-Poiseuille equation was applied to estimate the TFC-NF membrane pore size ∼0.45 nm.

  8. Thin-film Nanofibrous Composite Membranes Containing Cellulose or Chitin Barrier Layers Fabricated by Ionic Liquids

    SciTech Connect

    H Ma; B Hsiao; B Chu

    2011-12-31

    The barrier layer of high-flux ultrafiltration (UF) thin-film nanofibrous composite (TFNC) membranes for purification of wastewater (e.g., bilge water) have been prepared by using cellulose, chitin, and a cellulose-chitin blend, regenerated from an ionic liquid. The structures and properties of regenerated cellulose, chitin, and a cellulose-chitin blend were analyzed with thermogravimetric analysis (TGA) and wide-angle X-ray diffraction (WAXD). The surface morphology, pore size and pore size distribution of TFNC membranes were determined by SEM images and molecular weight cut-off (MWCO) methods. An oil/water emulsion, a model of bilge water, was used as the feed solution, and the permeation flux and rejection ratio of the membranes were investigated. TFNC membranes based on the cellulose-chitin blend exhibited 10 times higher permeation flux when compared with a commercial UF membrane (PAN10, Sepro) with a similar rejection ratio after filtration over a time period of up to 100 h, implying the practical feasibility of such membranes for UF applications.

  9. Fatigue characteristics of polycrystalline silicon thin-film membrane and its dependence on humidity

    NASA Astrophysics Data System (ADS)

    Tanemura, Tomoki; Yamashita, Shuichi; Wado, Hiroyuki; Takeuchi, Yukihiro; Tsuchiya, Toshiyuki; Tabata, Osamu

    2013-03-01

    This paper describes fatigue characteristics of a polycrystalline silicon thin-film membrane under different humidity evaluated by out-of-plane resonant vibration. The membrane, without the surface of sidewalls by patterning of photolithography and etching process, was applied to evaluate fatigue characteristics precisely against the changes in the surrounding humidity owing to narrower deviation in the fatigue lifetime. The membrane has 16 mm square-shaped multilayered films consisting of a 250 or 500 nm thick polysilicon film on silicon dioxide and silicon nitride underlying layers. A circular weight of 12 mm in diameter was placed at the center of the membrane to control the resonant frequency. Stress on the polysilicon film was generated by deforming the membrane oscillating the weight in the out-of-plane direction. The polysilicon film was fractured by fatigue damage accumulation under cyclic stress. The lifetime of the polysilicon membrane extended with lower relative humidity, especially at 5%RH. The results of the fatigue tests were well formulated with Weibull's statistics and Paris’ law. The dependence of fatigue characteristics on humidity has been quantitatively revealed for the first time. The crack growth rate indicated by the fatigue index decreased with the reduction in humidity, whereas the deviation of strength represented by the Weibull modulus was nearly constant against humidity.

  10. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOEpatents

    Jankowski, Alan F.; Makowiecki, Daniel M.; Rambach, Glenn D.; Randich, Erik

    1998-01-01

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

  11. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOEpatents

    Jankowski, Alan F.; Makowiecki, Daniel M.; Rambach, Glenn D.; Randich, Erik

    1999-01-01

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated.

  12. Hybrid deposition of thin film solid oxide fuel cells and electrolyzers

    DOEpatents

    Jankowski, A.F.; Makowiecki, D.M.; Rambach, G.D.; Randich, E.

    1998-05-19

    The use of vapor deposition techniques enables synthesis of the basic components of a solid oxide fuel cell (SOFC); namely, the electrolyte layer, the two electrodes, and the electrolyte-electrode interfaces. Such vapor deposition techniques provide solutions to each of the three critical steps of material synthesis to produce a thin film solid oxide fuel cell (TFSOFC). The electrolyte is formed by reactive deposition of essentially any ion conducting oxide, such as defect free, yttria stabilized zirconia (YSZ) by planar magnetron sputtering. The electrodes are formed from ceramic powders sputter coated with an appropriate metal and sintered to a porous compact. The electrolyte-electrode interface is formed by chemical vapor deposition of zirconia compounds onto the porous electrodes to provide a dense, smooth surface on which to continue the growth of the defect-free electrolyte, whereby a single fuel cell or multiple cells may be fabricated. 8 figs.

  13. Enhanced surface hydrophilicity of thin-film composite membranes for nanofiltration: an experimental and DFT study.

    PubMed

    Lv, Zhiwei; Hu, Jiahui; Zhang, Xuan; Wang, Lianjun

    2015-10-01

    In the current study, thin-film composite (TFC) nanofiltration membranes desirable for water softening were successfully developed through interfacial polymerization using N-(2-hydroxyethyl)ethylenediamine (HEDA) as the amine monomer in the aqueous phase. The hydrophilicity of the membrane surface was greatly enhanced with the introduction of the residual hydroxyl groups during the fabrication process. The TFC membranes possessed a permeate flux of 15.8 L m(-2) h(-1) under 0.6 MPa, with a rejection of 85.9%, 73.8%, and 99.8% for Na2SO4, MgSO4 and Congo red, respectively. The interplays of the solvent, solute and polymer matrix on the separation performance were investigated by means of the solubility parameter study. Moreover, density functional theory was employed to calculate the Fukui function by the Hirshfeld charge, which gave the global and local softness values to predict the reactivity of the atomic sites in the HEDA molecule. The findings of this study support the possible forming mechanism of the barrier layer for the first time. The TFC membrane was found to be stable and displayed good separation ability over a week-long filtration process. The combined results of this work suggest that these HEDA/TMC TFC nanofiltration membranes are promising candidates for various applications, such as desalination and dye removal from wastewater.

  14. Toward Effective Shell Modeling of Wrinkled Thin-Film Membranes Exhibiting Stress Concentrations

    NASA Technical Reports Server (NTRS)

    Tessler, Alexander; Sleight, David W.

    2004-01-01

    Geometrically nonlinear shell finite element analysis has recently been applied to solar-sail membrane problems in order to model the out-of-plane deformations due to structural wrinkling. Whereas certain problems lend themselves to achieving converged nonlinear solutions that compare favorably with experimental observations, solutions to tensioned membranes exhibiting high stress concentrations have been difficult to obtain even with the best nonlinear finite element codes and advanced shell element technology. In this paper, two numerical studies are presented that pave the way to improving the modeling of this class of nonlinear problems. The studies address the issues of mesh refinement and stress-concentration alleviation, and the effects of these modeling strategies on the ability to attain converged nonlinear deformations due to wrinkling. The numerical studies demonstrate that excessive mesh refinement in the regions of stress concentration may be disadvantageous to achieving wrinkled equilibrium states, causing the nonlinear solution to lock in the membrane response mode, while totally discarding the very low-energy bending response that is necessary to cause wrinkling deformation patterns. An element-level, strain-energy density criterion is suggested for facilitating automated, adaptive mesh refinements specifically aimed at the modeling of thin-film membranes undergoing wrinkling deformations.

  15. Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation.

    PubMed

    Bae, Kyuyoung; Kang, Gumin; Cho, Suehyun K; Park, Wounjhang; Kim, Kyoungsik; Padilla, Willie J

    2015-12-14

    Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0-200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400-2,500 nm and the microscale funnel structures lead to average reflection of 7% at 2.5-17 μm. This membrane allows heat localization within the few micrometre-thick layer and continuous water provision through micropores. We efficiently generate water vapour with solar thermal conversion efficiency up to 57% at 20 kW m(-2). This new structure has a variety of applications in solar energy harvesting, thermoplasmonics and related technologies.

  16. Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation.

    PubMed

    Bae, Kyuyoung; Kang, Gumin; Cho, Suehyun K; Park, Wounjhang; Kim, Kyoungsik; Padilla, Willie J

    2015-01-01

    Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0-200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400-2,500 nm and the microscale funnel structures lead to average reflection of 7% at 2.5-17 μm. This membrane allows heat localization within the few micrometre-thick layer and continuous water provision through micropores. We efficiently generate water vapour with solar thermal conversion efficiency up to 57% at 20 kW m(-2). This new structure has a variety of applications in solar energy harvesting, thermoplasmonics and related technologies. PMID:26657535

  17. Flexible thin-film black gold membranes with ultrabroadband plasmonic nanofocusing for efficient solar vapour generation

    PubMed Central

    Bae, Kyuyoung; Kang, Gumin; Cho, Suehyun K.; Park, Wounjhang; Kim, Kyoungsik; Padilla, Willie J.

    2015-01-01

    Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light absorption and high plasmon dissipation loss. Here we demonstrate large area, flexible thin-film black gold membranes, which have multiscale structures of varying metallic nanoscale gaps (0–200 nm) as well as microscale funnel structures. The adiabatic nanofocusing of self-aggregated metallic nanowire bundle arrays produces average absorption of 91% at 400–2,500 nm and the microscale funnel structures lead to average reflection of 7% at 2.5–17 μm. This membrane allows heat localization within the few micrometre-thick layer and continuous water provision through micropores. We efficiently generate water vapour with solar thermal conversion efficiency up to 57% at 20 kW m−2. This new structure has a variety of applications in solar energy harvesting, thermoplasmonics and related technologies. PMID:26657535

  18. Spray Layer-by-Layer Assembled Clay Composite Thin Films as Selective Layers in Reverse Osmosis Membranes.

    PubMed

    Kovacs, Jason R; Liu, Chaoyang; Hammond, Paula T

    2015-06-24

    Spray layer-by-layer assembled thin films containing laponite (LAP) clay exhibit effective salt barrier and water permeability properties when applied as selective layers in reverse osmosis (RO) membranes. Negatively charged LAP platelets were layered with poly(diallyldimethylammonium) (PDAC), poly(allylamine) (PAH), and poly(acrylic acid) (PAA) in bilayer and tetralayer film architectures to generate uniform films on the order of 100 nm thick that bridge a porous poly(ether sulfone) support to form novel RO membranes. Nanostructures were formed of clay layers intercalated in a polymeric matrix that introduced size-exclusion transport mechanisms into the selective layer. Thermal cross-linking of the polymeric matrix was used to increase the mechanical stability of the films and improve salt rejection by constraining swelling during operation. Maximum salt rejection of 89% was observed for the tetralayer film architecture, with an order of magnitude increase in water permeability compared to commercially available TFC-HR membranes. These clay composite thin films could serve as a high-flux alternative to current polymeric RO membranes for wastewater and brackish water treatment as well as potentially for forward osmosis applications. In general, we illustrate that by investigating the composite systems accessed using alternating layer-by-layer assembly in conjunction with complementary covalent cross-linking, it is possible to design thin film membranes with tunable transport properties for water purification applications.

  19. TAPE CALENDERING MANUFACTURING PROCESS FOR MULTILAYER THIN-FILM SOLID OXIDE FUEL CELLS

    SciTech Connect

    Nguyen Minh; Kurt Montgomery

    2004-10-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the Phases I and II under Contract DE-AC26-00NT40705 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Tape Calendering Manufacturing Process For Multilayer Thin-Film Solid Oxide Fuel Cells''. The main objective of this project was to develop the manufacturing process based on tape calendering for multilayer solid oxide fuel cells (SOFC's) using the unitized cell design concept and to demonstrate cell performance under specified operating conditions. Summarized in this report is the development and improvements to multilayer SOFC cells and the unitized cell design. Improvements to the multilayer SOFC cell were made in electrochemical performance, in both the anode and cathode, with cells demonstrating power densities of nearly 0.9 W/cm{sup 2} for 650 C operation and other cell configurations showing greater than 1.0 W/cm{sup 2} at 75% fuel utilization and 800 C. The unitized cell design was matured through design, analysis and development testing to a point that cell operation at greater than 70% fuel utilization was demonstrated at 800 C. The manufacturing process for both the multilayer cell and unitized cell design were assessed and refined, process maps were developed, forming approaches explored, and nondestructive evaluation (NDE) techniques examined.

  20. Thin-film composite pressure retarded osmosis membranes for sustainable power generation from salinity gradients.

    PubMed

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A; Schiffman, Jessica D; Hoover, Laura A; Kim, Yu Chang; Elimelech, Menachem

    2011-05-15

    Pressure retarded osmosis has the potential to produce renewable energy from natural salinity gradients. This work presents the fabrication of thin-film composite membranes customized for high performance in pressure retarded osmosis. We also present the development of a theoretical model to predict the water flux in pressure retarded osmosis, from which we can predict the power density that can be achieved by a membrane. The model is the first to incorporate external concentration polarization, a performance limiting phenomenon that becomes significant for high-performance membranes. The fabricated membranes consist of a selective polyamide layer formed by interfacial polymerization on top of a polysulfone support layer made by phase separation. The highly porous support layer (structural parameter S = 349 μm), which minimizes internal concentration polarization, allows the transport properties of the active layer to be customized to enhance PRO performance. It is shown that a hand-cast membrane that balances permeability and selectivity (A = 5.81 L m(-2) h(-1) bar(-1), B = 0.88 L m(-2) h(-1)) is projected to achieve the highest potential peak power density of 10.0 W/m(2) for a river water feed solution and seawater draw solution. The outstanding performance of this membrane is attributed to the high water permeability of the active layer, coupled with a moderate salt permeability and the ability of the support layer to suppress the undesirable accumulation of leaked salt in the porous support. Membranes with greater selectivity (i.e., lower salt permeability, B = 0.16 L m(-2) h(-1)) suffered from a lower water permeability (A = 1.74 L m(-2) h(-1) bar(-1)) and would yield a lower peak power density of 6.1 W/m(2), while membranes with a higher permeability and lower selectivity (A = 7.55 L m(-2) h(-1) bar(-1), B = 5.45 L m(-2) h(-1)) performed poorly due to severe reverse salt permeation, resulting in a similar projected peak power density of 6.1 W/m(2).

  1. Bench Scale Thin Film Composite Hollow Fiber Membranes for Post-Combustion Carbon Dioxide Capture

    SciTech Connect

    Glaser, Paul; Bhandari, Dhaval; Narang, Kristi; McCloskey, Pat; Singh, Surinder; Ananthasayanam, Balajee; Howson, Paul; Lee, Julia; Wroczynski, Ron; Stewart, Frederick; Orme, Christopher; Klaehn, John; McNally, Joshua; Rownaghi, Ali; Lu, Liu; Koros, William; Goizueta, Roberto; Sethi, Vijay

    2015-04-01

    GE Global Research, Idaho National Laboratory (INL), Georgia Institute of Technology (Georgia Tech), and Western Research Institute (WRI) proposed to develop high performance thin film polymer composite hollow fiber membranes and advanced processes for economical post-combustion carbon dioxide (CO2) capture from pulverized coal flue gas at temperatures typical of existing flue gas cleanup processes. The project sought to develop and then optimize new gas separations membrane systems at the bench scale, including tuning the properties of a novel polyphosphazene polymer in a coating solution and fabricating highly engineered porous hollow fiber supports. The project also sought to define the processes needed to coat the fiber support to manufacture composite hollow fiber membranes with high performance, ultra-thin separation layers. Physical, chemical, and mechanical stability of the materials (individual and composite) towards coal flue gas components was considered via exposure and performance tests. Preliminary design, technoeconomic, and economic feasibility analyses were conducted to evaluate the overall performance and impact of the process on the cost of electricity (COE) for a coal-fired plant including capture technologies. At the onset of the project, Membranes based on coupling a novel selective material polyphosphazene with an engineered hollow fiber support was found to have the potential to capture greater than 90% of the CO2 in flue gas with less than 35% increase in COE, which would achieve the DOE-targeted performance criteria. While lab-scale results for the polyphosphazene materials were very promising, and the material was incorporated into hollow-fiber modules, difficulties were encountered relating to the performance of these membrane systems over time. Performance, as measured by both flux of and selectivity for CO2 over other flue gas constituents was found to deteriorate over time, suggesting a system that was

  2. High-flux Thin-film Nanofibrous Composite Ultrafiltration Membranes Containing Cellulose Barrier Layer

    SciTech Connect

    Ma, H.; Yoon, K; Rong, L; Mao, Y; Mo, Z; Fang, D; Hollander, Z; Gaiteri, J; Hsiao , B; Chu, B

    2010-01-01

    A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNCmembranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNCmembrane was significantly higher (e.g. 10x) than comparable commercial UFmembranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2000 KDa, implying that the nominal pore size of the membrane was less than 50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNCmembranes, while different sources of cellulose

  3. Zeolitic Imidazolate Framework/Graphene Oxide Hybrid Nanosheets Functionalized Thin Film Nanocomposite Membrane for Enhanced Antimicrobial Performance.

    PubMed

    Wang, Jing; Wang, Yuanming; Zhang, Yatao; Uliana, Adam; Zhu, Junyong; Liu, Jindun; Van der Bruggen, Bart

    2016-09-28

    Inspired by the rational design concept, a novel antimicrobial agent zeolitic imidazolate framework-8 (ZIF-8)/graphene oxide (GO) was synthesized and utilized as a novel and efficient bactericidal agent to fabricate antimicrobial thin film nanocomposite (TFN) membranes via interfacial polymerization. The resultant hybrid nanosheets not only integrates the merits of both ZIF-8 and GO but also yields a uniform dispersion of ZIF-8 onto GO nanosheets simultaneously, thus effectively eliminating the agglomeration of ZIF-8 in the active layer of membranes. A ZIF-8/GO thin film nanocomposite (TFN-ZG) membrane with typical water permeability (40.63 L m(-2) h(-1) MPa(-1)) allows for efficient bivalent salt removal (rejections of Na2SO4 and MgSO4 were 100% and 77%, respectively). Furthermore, the synthesized ZIF-8/GO nanocomposites were verified to have an optimal antimicrobial activity (MIC,128 μg/mL) in comparison with ZIF-8 and GO separately, which sufficiently endowed the TFN-ZG membrane with excellent antimicrobial activity (84.3% for TFN-ZG3). Besides, the antimicrobial mechanisms of ZIF-8/GO hybrid nanosheets and TFN-ZG membranes were proposed. ZIF-8/GO functionalized membrane with high antimicrobial activity and salt retention denoted its great potential in water desalination, and we suggest that ZIF-8 based crystal may offer a new pathway for the synthesis of a multifunctional bactericide.

  4. Zeolitic Imidazolate Framework/Graphene Oxide Hybrid Nanosheets Functionalized Thin Film Nanocomposite Membrane for Enhanced Antimicrobial Performance.

    PubMed

    Wang, Jing; Wang, Yuanming; Zhang, Yatao; Uliana, Adam; Zhu, Junyong; Liu, Jindun; Van der Bruggen, Bart

    2016-09-28

    Inspired by the rational design concept, a novel antimicrobial agent zeolitic imidazolate framework-8 (ZIF-8)/graphene oxide (GO) was synthesized and utilized as a novel and efficient bactericidal agent to fabricate antimicrobial thin film nanocomposite (TFN) membranes via interfacial polymerization. The resultant hybrid nanosheets not only integrates the merits of both ZIF-8 and GO but also yields a uniform dispersion of ZIF-8 onto GO nanosheets simultaneously, thus effectively eliminating the agglomeration of ZIF-8 in the active layer of membranes. A ZIF-8/GO thin film nanocomposite (TFN-ZG) membrane with typical water permeability (40.63 L m(-2) h(-1) MPa(-1)) allows for efficient bivalent salt removal (rejections of Na2SO4 and MgSO4 were 100% and 77%, respectively). Furthermore, the synthesized ZIF-8/GO nanocomposites were verified to have an optimal antimicrobial activity (MIC,128 μg/mL) in comparison with ZIF-8 and GO separately, which sufficiently endowed the TFN-ZG membrane with excellent antimicrobial activity (84.3% for TFN-ZG3). Besides, the antimicrobial mechanisms of ZIF-8/GO hybrid nanosheets and TFN-ZG membranes were proposed. ZIF-8/GO functionalized membrane with high antimicrobial activity and salt retention denoted its great potential in water desalination, and we suggest that ZIF-8 based crystal may offer a new pathway for the synthesis of a multifunctional bactericide. PMID:27588551

  5. Thin film photovoltaics

    SciTech Connect

    Zweibel, K; Ullal, H S

    1989-05-01

    Thin films are considered a potentially attractive technological approach to making cost-effective electricity by photovoltaics. Over the last twenty years, many have been investigated and some (cadmium telluride, copper indium diselenide, amorphous silicon) have become leading candidates for future large-scale commercialization. This paper surveys the past development of these key thin films and gives their status and future prospects. In all cases, significant progress toward cost-effective PV electricity has been made. If this progress continues, it appears that thin film PV could provide electricity that is competitive for summer daytime peaking power requirements by the middle of the 1990s; and electricity in a range that is competitive with fossil fuel costs (i.e., 6 cents/kilowatt-hour) should be available from PV around the turn of the century. 22 refs., 9 figs.

  6. Preparation and Characterization of Chitosan Thin Films on Mixed-Matrix Membranes for Complete Removal of Chromium

    PubMed Central

    Nayak, Vignesh; Jyothi, Mannekote Shivanna; Balakrishna, R Geetha; Padaki, Mahesh; Ismail, Ahmad Fauzi

    2015-01-01

    Herein we present a new approach for the complete removal of CrVI species, through reduction of CrVI to CrIII, followed by adsorption of CrIII. Reduction of chromium from water is an important challenge, as CrIV is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSf < PSf/TiO2 < PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of CrVI to CrIII through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced CrIII species are adsorbed onto the CS layer via complexation to give chromium-free water. PMID:26246989

  7. Preparation and Characterization of Chitosan Thin Films on Mixed-Matrix Membranes for Complete Removal of Chromium.

    PubMed

    Nayak, Vignesh; Jyothi, Mannekote Shivanna; Balakrishna, R Geetha; Padaki, Mahesh; Ismail, Ahmad Fauzi

    2015-06-01

    Herein we present a new approach for the complete removal of Cr(VI) species, through reduction of Cr(VI) to Cr(III), followed by adsorption of Cr(III). Reduction of chromium from water is an important challenge, as Cr(IV) is one of the most toxic substances emitted from industrial processes. Chitosan (CS) thin films were developed on plain polysulfone (PSf) and PSf/TiO2 membrane substrates by a temperature-induced technique using polyvinyl alcohol as a binder. Structure property elucidation was carried out by X-ray diffraction, microscopy, spectroscopy, contact angle measurement, and water uptake studies. The increase in hydrophilicity followed the order: PSf < PSf/TiO2 < PSf/TiO2/CS membranes. Use of this thin-film composite membrane for chromium removal was investigated with regards to the effects of light and pH. The observations reveal 100 % reduction of Cr(VI) to Cr(III) through electrons and protons donated from OH and NH2 groups of the CS layer; the reduced Cr(III) species are adsorbed onto the CS layer via complexation to give chromium-free water. PMID:26246989

  8. Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor.

    PubMed

    Khan, Mohiuddin; Danielsen, Steffen; Johansen, Katja; Lorenz, Lindsey; Nelson, Sara; Camper, Anne

    2014-02-01

    Application of environmentally friendly enzymes to remove thin-film composite (TFC) reverse osmosis (RO) membrane biofoulants without changing the physico-chemical properties of the RO surface is a challenging and new concept. Eight enzymes from Novozyme A/S were tested using a commercially available biofouling-resistant TFC polyamide RO membrane (BW30, FilmTech Corporation, Dow Chemical Co.) without filtration in a rotating disk reactor system operated for 58 days. At the end of the operation, the accumulated biofoulants on the TFC RO surfaces were treated with the three best enzymes, Subtilisin protease and lipase; dextranase; and polygalacturonase (PG) based enzymes, at neutral pH (~7) and doses of 50, 100, and 150 ppm. Contact times were 18 and 36 h. Live/dead staining, epifluorescence microscopy measurements, and 5 μm thick cryo-sections of enzyme and physically treated biofouled membranes revealed that Subtilisin protease- and lipase-based enzymes at 100 ppm and 18 h contact time were optimal for removing most of the cells and proteins from the RO surface. Culturable cells inside the biofilm declined by more than five logs even at the lower dose (50 ppm) and shorter incubation period (18 h). Subtilisin protease- and lipase-based enzyme cleaning at 100 ppm and for 18 h contact time restored the hydrophobicity of the TFC RO surface to its virgin condition while physical cleaning alone resulted in a 50° increase in hydrophobicity. Moreover, at this optimum working condition, the Subtilisin protease- and lipase-based enzyme treatment of biofouled RO surface also restored the surface roughness measured with atomic force microscopy and the mass percentage of the chemical compositions on the TFC surface estimated with X-ray photoelectron spectroscopy to its virgin condition. This novel study will encourage the further development and application of enzymes to remove biofoulants on the RO surface without changing its surface properties.

  9. Enzymatic cleaning of biofouled thin-film composite reverse osmosis (RO) membrane operated in a biofilm membrane reactor.

    PubMed

    Khan, Mohiuddin; Danielsen, Steffen; Johansen, Katja; Lorenz, Lindsey; Nelson, Sara; Camper, Anne

    2014-02-01

    Application of environmentally friendly enzymes to remove thin-film composite (TFC) reverse osmosis (RO) membrane biofoulants without changing the physico-chemical properties of the RO surface is a challenging and new concept. Eight enzymes from Novozyme A/S were tested using a commercially available biofouling-resistant TFC polyamide RO membrane (BW30, FilmTech Corporation, Dow Chemical Co.) without filtration in a rotating disk reactor system operated for 58 days. At the end of the operation, the accumulated biofoulants on the TFC RO surfaces were treated with the three best enzymes, Subtilisin protease and lipase; dextranase; and polygalacturonase (PG) based enzymes, at neutral pH (~7) and doses of 50, 100, and 150 ppm. Contact times were 18 and 36 h. Live/dead staining, epifluorescence microscopy measurements, and 5 μm thick cryo-sections of enzyme and physically treated biofouled membranes revealed that Subtilisin protease- and lipase-based enzymes at 100 ppm and 18 h contact time were optimal for removing most of the cells and proteins from the RO surface. Culturable cells inside the biofilm declined by more than five logs even at the lower dose (50 ppm) and shorter incubation period (18 h). Subtilisin protease- and lipase-based enzyme cleaning at 100 ppm and for 18 h contact time restored the hydrophobicity of the TFC RO surface to its virgin condition while physical cleaning alone resulted in a 50° increase in hydrophobicity. Moreover, at this optimum working condition, the Subtilisin protease- and lipase-based enzyme treatment of biofouled RO surface also restored the surface roughness measured with atomic force microscopy and the mass percentage of the chemical compositions on the TFC surface estimated with X-ray photoelectron spectroscopy to its virgin condition. This novel study will encourage the further development and application of enzymes to remove biofoulants on the RO surface without changing its surface properties. PMID:24329165

  10. In situ surface chemical modification of thin-film composite forward osmosis membranes for enhanced organic fouling resistance.

    PubMed

    Lu, Xinglin; Romero-Vargas Castrillón, Santiago; Shaffer, Devin L; Ma, Jun; Elimelech, Menachem

    2013-01-01

    Forward osmosis (FO) is an emerging membrane-based water separation process with potential applications in a host of environmental and industrial processes. Nevertheless, membrane fouling remains a technical obstacle affecting this technology, increasing operating costs and decreasing membrane life. This work presents the first fabrication of an antifouling thin-film composite (TFC) FO membrane by an in situ technique without postfabrication treatment. The membrane was fabricated and modified in situ, grafting Jeffamine, an amine-terminated poly(ethylene glycol) derivative, to dangling acyl chloride surface groups on the nascent polyamide active layer. Surface characterization by contact angle, Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), zeta potential, atomic force microscopy (AFM), and fluorescence microscopy, confirms the presence of Jeffamine on the membrane surface. We demonstrate the improved fouling resistance of the in situ modified membranes through accelerated dynamic fouling FO experiments using a synthetic wastewater feed solution at high concentration (250 mg/L) of alginate, a model macromolecule for the hydrophilic fraction of wastewater effluent organic matter. Our results show a significantly lower flux decline for the in situ modified membranes compared to pristine polyamide (14.3 ± 2.7% vs 2.8 ± 1.4%, respectively). AFM adhesion force measurements between the membrane and a carboxylate-modified latex particle, a surrogate for the organic (alginate) foulant, show weaker foulant-membrane interactions, further confirming the enhanced fouling resistance of the in situ modified membranes. PMID:24066902

  11. In situ surface chemical modification of thin-film composite forward osmosis membranes for enhanced organic fouling resistance.

    PubMed

    Lu, Xinglin; Romero-Vargas Castrillón, Santiago; Shaffer, Devin L; Ma, Jun; Elimelech, Menachem

    2013-01-01

    Forward osmosis (FO) is an emerging membrane-based water separation process with potential applications in a host of environmental and industrial processes. Nevertheless, membrane fouling remains a technical obstacle affecting this technology, increasing operating costs and decreasing membrane life. This work presents the first fabrication of an antifouling thin-film composite (TFC) FO membrane by an in situ technique without postfabrication treatment. The membrane was fabricated and modified in situ, grafting Jeffamine, an amine-terminated poly(ethylene glycol) derivative, to dangling acyl chloride surface groups on the nascent polyamide active layer. Surface characterization by contact angle, Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), zeta potential, atomic force microscopy (AFM), and fluorescence microscopy, confirms the presence of Jeffamine on the membrane surface. We demonstrate the improved fouling resistance of the in situ modified membranes through accelerated dynamic fouling FO experiments using a synthetic wastewater feed solution at high concentration (250 mg/L) of alginate, a model macromolecule for the hydrophilic fraction of wastewater effluent organic matter. Our results show a significantly lower flux decline for the in situ modified membranes compared to pristine polyamide (14.3 ± 2.7% vs 2.8 ± 1.4%, respectively). AFM adhesion force measurements between the membrane and a carboxylate-modified latex particle, a surrogate for the organic (alginate) foulant, show weaker foulant-membrane interactions, further confirming the enhanced fouling resistance of the in situ modified membranes.

  12. In situ formation of silver nanoparticles on thin-film composite reverse osmosis membranes for biofouling mitigation.

    PubMed

    Ben-Sasson, Moshe; Lu, Xinglin; Bar-Zeev, Edo; Zodrow, Katherine R; Nejati, Siamak; Qi, Genggeng; Giannelis, Emmanuel P; Elimelech, Menachem

    2014-10-01

    The potential to incorporate silver nanoparticles (Ag-NPs) as biocides in membranes for water purification has gained much interest in recent years. However, a viable strategy for loading the Ag-NPs on the membrane remains challenging. This paper presents a novel, facile procedure for loading Ag-NPs on thin-film composite (TFC) reverse osmosis membranes. Reaction of silver salt with a reducing agent on the membrane surface resulted in uniform coverage of Ag-NPs, irreversibly bound to the membrane, as confirmed by XPS, TEM, and SEM analyses. Salt selectivity of the membrane as well its surface roughness, hydrophilicity, and zeta potential were not impacted by Ag-NP functionalization, while a slight reduction (up to 17%) in water permeability was observed. The formed Ag-NPs imparted strong antibacterial activity to the membrane, leading to reduction of more than 75% in the number of live bacteria attached to the membrane for three model bacteria strains. In addition, confocal microscopy analyses revealed that Ag-NPs significantly suppressed biofilm formation, with 41% reduction in total biovolume and significant reduction in EPS, dead, and live bacteria on the functionalized membrane. The simplicity of the method, the short reaction time, the ability to load the Ag-NPs on site, and the strong imparted antibacterial activity highlight the potential of this method in real-world RO membrane applications.

  13. Thin Film?

    NASA Astrophysics Data System (ADS)

    Kariper, İ. Afşin

    2014-09-01

    This study focuses on the critical surface tension of lead sulfite (PbSO3) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO3 thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO3 thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension.

  14. Nanoporous thin-film membranes from block-polymers : using self-consistent field theory calculations to guide polymer synthesis.

    SciTech Connect

    Cordaro, Joseph Gabriel

    2010-12-01

    The controlled self-assembly of polymer thin-films into ordered domains has attracted significant academic and industrial interest. Most work has focused on controlling domain size and morphology through modification of the polymer block-lengths, n, and the Flory-Huggins interaction parameter, {chi}. Models, such as Self-Consistent Field Theory (SCFT), have been successful in describing the experimentally observed morphology of phase-separated polymers. We have developed a computational method which uses SCFT calculations as a predictive tool in order to guide our polymer synthesis. Armed with this capability, we have the ability to select {chi} and then search for an ideal value of n such that a desired morphology is the most thermodynamically favorable. This approach enables us to synthesize new block-polymers with the exactly segment lengths that will undergo self-assembly to the desired morphology. As proof-of-principle we have used our model to predict the gyroidal domain for various block lengths using a fixed {chi} value. To validate our computational model, we have synthesized a series of block-copolymers in which only the total molecular length changes. All of these materials have a predicted thermodynamically favorable gyroidal morphology based on the results of our SCFT calculations. Thin-films of these polymers are cast and annealed in order to equilibrate the structure. Final characterization of the polymer thin-film morphology has been performed. The accuracy of our calculations compared to experimental results is discussed. Extension of this predictive ability to tri-block polymer systems and the implications to making functionalizable nanoporous membranes will be discussed.

  15. Comparison of biofouling mechanisms between cellulose triacetate (CTA) and thin-film composite (TFC) polyamide forward osmosis membranes in osmotic membrane bioreactors.

    PubMed

    Wang, Xinhua; Zhao, Yanxiao; Yuan, Bo; Wang, Zhiwei; Li, Xiufen; Ren, Yueping

    2016-02-01

    There are two types of popular forward osmosis (FO) membrane materials applied for researches on FO process, cellulose triacetate (CTA) and thin film composite (TFC) polyamide. However, performance and fouling mechanisms of commercial TFC FO membrane in osmotic membrane bioreactors (OMBRs) are still unknown. In current study, its biofouling behaviors in OMBRs were investigated and further compared to the CTA FO membrane. The results indicated that β-D-glucopyranose polysaccharides and microorganisms accounted for approximately 77% of total biovolume on the CTA FO membrane while β-D-glucopyranose polysaccharides (biovolume ratio of 81.1%) were the only dominant biofoulants on the TFC FO membrane. The analyses on the biofouling structure implied that a tighter biofouling layer with a larger biovolume was formed on the CTA FO membrane. The differences in biofouling behaviors including biofoulants composition and biofouling structure between CTA and TFC FO membranes were attributed to different membrane surface properties. PMID:26700758

  16. Comparison of biofouling mechanisms between cellulose triacetate (CTA) and thin-film composite (TFC) polyamide forward osmosis membranes in osmotic membrane bioreactors.

    PubMed

    Wang, Xinhua; Zhao, Yanxiao; Yuan, Bo; Wang, Zhiwei; Li, Xiufen; Ren, Yueping

    2016-02-01

    There are two types of popular forward osmosis (FO) membrane materials applied for researches on FO process, cellulose triacetate (CTA) and thin film composite (TFC) polyamide. However, performance and fouling mechanisms of commercial TFC FO membrane in osmotic membrane bioreactors (OMBRs) are still unknown. In current study, its biofouling behaviors in OMBRs were investigated and further compared to the CTA FO membrane. The results indicated that β-D-glucopyranose polysaccharides and microorganisms accounted for approximately 77% of total biovolume on the CTA FO membrane while β-D-glucopyranose polysaccharides (biovolume ratio of 81.1%) were the only dominant biofoulants on the TFC FO membrane. The analyses on the biofouling structure implied that a tighter biofouling layer with a larger biovolume was formed on the CTA FO membrane. The differences in biofouling behaviors including biofoulants composition and biofouling structure between CTA and TFC FO membranes were attributed to different membrane surface properties.

  17. In Situ Reduction of Silver by Polydopamine: A Novel Antimicrobial Modification of a Thin-Film Composite Polyamide Membrane.

    PubMed

    Yang, Zhe; Wu, Yichao; Wang, Jianqiang; Cao, Bin; Tang, Chuyang Y

    2016-09-01

    We report a facile method for the antimicrobial modification of a thin-film composite polyamide reverse osmosis (RO) membrane. The membrane surface was first coated with polydopamine (PDA), whose reducing catechol groups subsequently immobilized silver ions in situ to form uniformly dispersed silver nanoparticles (AgNPs) inside the coating layer. Agglomeration of AgNPs was not observed despite a high silver loading of 13.3 ± 0.3 μg/cm(2) (corresponding to a surface coverage of 18.5% by the nanoparticles). Both diffusion inhibition zone tests and colony formation unit tests showed clear antimicrobial effects of the silver loaded membranes on model bacteria Bacillus subtilis and Escherichia coli. Furthermore, the silver immobilized membrane had significantly enhanced salt rejection compared to the control PDA coated membrane, which is attributed to the preferential formation of AgNPs at defect sides within the PDA layer. This self-healing mechanism can be used to prepare antimicrobial RO membranes with improved salt rejection without scarifying the membrane permeability, which provides a new dimension for membrane surface modification. PMID:27479138

  18. Preparation of thin film nanofibrous composite NF membrane based on EDC/NHS modified PAN-AA nanofibrous substrate

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Wang, X.; Hsiao, B. S.

    2016-07-01

    A novel kind of thin-film nanofibrous composite (TFNC) nanofiltration (NF) membranes consisting of a polyamide (PA) barrier layer were successfully fabricated by interfacial polymerization (IFP) based on electrospun double-layer nanofibrous substrates, which have an ultrathin poly (acrylonitrile-co-acrylic acid) (PAN-AA) nanofibrous layer as top layer and a thicker polyacrylonitrile (PAN) nanofiber layer as bottom porous support layer. Immersing PAN/PAN-AA nanofibrous substrates into 1-ethyl-(3-3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) aqueous solution and piperazine (PIP) aqueous solution (0.20 wt%) sequentially for a period of time, the carboxyl groups on PAN-AA nanofibers were activated by carbodiimide and then reacted with the amide groups. The as prepared composite membrane has an integrated structure with high rejection rate (98.0%); high permeate flux (40.4 L/m2h) for MgSO4 aqueous solution (2 g/L).

  19. Influence of silica nanospheres on the separation performance of thin film composite poly(piperazine-amide) nanofiltration membranes

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Wang, Yihua; Song, Jie; Guan, Yipeng; Yu, Hui; Pan, Xianhui; Wu, Feiyang; Zhang, Meng

    2015-01-01

    A novel thin film nanocomposite nanofiltration (TFNN) membrane was fabricated by introducing silica nanospheres (ca. 235 ± 11 nm) in the interfacial polymerization process of trimesoyl chloride (TMC) and piperazine (PIP) over polysulfone (PS) support for investigating the effect of silica nanofiller on the separation performance (i.e., permeability and salt rejection) of conventional thin film composite poly(piperazine-amide) nanofiltration (TFCN) membrane. The physicochemical characterization results show that all of the silica nanospheres are uniformly embedded on the surface of TFNN membrane. The introduction of silica nanospheres improves the hydrophilicity of the TFCN membrane and also causes its isoelectric point shift to a lower pH value. Moreover, the active poly(piperazine-amide) barrier layer of TFNN membrane (60.8 ± 2.3 nm) is thinner than that of the pristine TFCN membrane (72.1 ± 2.5 nm) as a control sample. The separation performance tests reveal that the addition of silica nanospheres can obviously elevate the salt rejection of the pristine TFCN membrane from 87.58 ± 0.15 to 94.81 ± 0.17% under 2000 ppm of MgSO4 solution and 0.5 MPa operating pressure, simultaneously accompanied by the increases of permeate flux from 19.36 ± 0.75 to 22.65 ± 0.68 L/m2 h. Additionally, compared with pristine TFCN membrane, the fabricated TFNN membrane has relatively low salt rejection (43.20 ± 0.27%) in 0.5 MPa operating pressure for 500 ppm of NaCl aqueous solution, which demonstrates that the introduction of silica nanospheres can dramatically promote the divalent-ionic separation selectivity. Furthermore, the experimental results suggest that the nanocomposite TFNN membrane possesses stable filtration performance in the softening process of MgSO4 aqueous solution. The separation performance improvement should be attributed to the optimizations of microstructures and surface features of active barrier layer of TFNN membrane, caused by the addition of silica

  20. Organic fouling of thin-film composite polyamide and cellulose triacetate forward osmosis membranes by oppositely charged macromolecules.

    PubMed

    Gu, Yangshuo; Wang, Yi-Ning; Wei, Jing; Tang, Chuyang Y

    2013-04-01

    Fouling of cellulose triacetate (CTA) and thin-film composite (TFC) forward osmosis (FO) membranes by organic macromolecules were studied using oppositely charged lysozyme (LYS) and alginate (ALG) as model foulants. Flux performance and foulant deposition on membranes were systematically investigated for a submerged membrane system. When an initial flux of 25 L/m(2)h was applied, both flux reduction and foulant mass deposition were severe for feed water containing the mixture of LYS and ALG (e.g., 50% LYS and 50% ALG at a total foulant concentration of 100 mg/L). In comparison, fouling was much milder for feed water containing either LYS or ALG alone. Compared to the CTA FO membrane, the TFC FO membrane showed greater fouling propensity under mild FO fouling conditions due to its much rougher surface. Nevertheless, under severe FO fouling conditions, fouling was dominated by foulant-deposited-foulant interaction and membrane surface properties played a less important role. Furthermore, when the feed water contained both LYS and ALG in sufficient amount, the deposited cake layer foulant composition (i.e., the LYS/ALG mass ratio) was not strongly affected by membrane types (CTA versus TFC) nor testing modes (pressure-driven NF mode versus osmosis-driven FO mode). In contrast, solution chemistry such as pH and calcium concentration had remarkable effect on the cake layer composition due to their effects on foulant-foulant interaction.

  1. Organic fouling of thin-film composite polyamide and cellulose triacetate forward osmosis membranes by oppositely charged macromolecules.

    PubMed

    Gu, Yangshuo; Wang, Yi-Ning; Wei, Jing; Tang, Chuyang Y

    2013-04-01

    Fouling of cellulose triacetate (CTA) and thin-film composite (TFC) forward osmosis (FO) membranes by organic macromolecules were studied using oppositely charged lysozyme (LYS) and alginate (ALG) as model foulants. Flux performance and foulant deposition on membranes were systematically investigated for a submerged membrane system. When an initial flux of 25 L/m(2)h was applied, both flux reduction and foulant mass deposition were severe for feed water containing the mixture of LYS and ALG (e.g., 50% LYS and 50% ALG at a total foulant concentration of 100 mg/L). In comparison, fouling was much milder for feed water containing either LYS or ALG alone. Compared to the CTA FO membrane, the TFC FO membrane showed greater fouling propensity under mild FO fouling conditions due to its much rougher surface. Nevertheless, under severe FO fouling conditions, fouling was dominated by foulant-deposited-foulant interaction and membrane surface properties played a less important role. Furthermore, when the feed water contained both LYS and ALG in sufficient amount, the deposited cake layer foulant composition (i.e., the LYS/ALG mass ratio) was not strongly affected by membrane types (CTA versus TFC) nor testing modes (pressure-driven NF mode versus osmosis-driven FO mode). In contrast, solution chemistry such as pH and calcium concentration had remarkable effect on the cake layer composition due to their effects on foulant-foulant interaction. PMID:23384517

  2. The potential and challenges of thin-film electrolyte and nanostructured electrode for yttria-stabilized zirconia-base anode-supported solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Noh, Ho-Sung; Yoon, Kyung Joong; Kim, Byung-Kook; Je, Hae-June; Lee, Hae-Weon; Lee, Jong-Ho; Son, Ji-Won

    2014-02-01

    Thin-film electrolytes and nanostructured electrodes are essential components for lowering the operation temperature of solid oxide fuel cells (SOFCs); however, reliably implementing thin-film electrolytes and nano-structure electrodes over a realistic SOFC platform, such as a porous anode-support, has been extremely difficult. If these components can be created reliably and reproducibly on porous substrates as anode supports, a more precise assessment of their impact on realistic SOFCs would be possible. In this work, structurally sound thin-film and nano-structured SOFC components consisting of a nano-composite NiO-yttria-stabilized zirconia (YSZ) anode interlayer, a thin YSZ and gadolinia-doped ceria (GDC) bi-layer electrolyte, and a nano-structure lanthanum strontium cobaltite (LSC)-base cathode, are sequentially fabricated on a porous NiO-YSZ anode support using thin-film technology. Using an optimized cell testing setup makes possible a more exact investigation of the potential and challenges of thin-film electrolyte and nanostructured electrode-based anode-supported SOFCs. Peak power densities obtained at 500 °C surpass 500 mW cm-2, which is an unprecedented low-temperature performance for the YSZ-based anode-supported SOFC. It is found that this critical, low-temperature performance for the anode-supported SOFC depends more on the electrode performance than the resistance of the thin-film electrolyte during lower temperature operation.

  3. Development and Characterization of a High Performance Thin-Film Planar Solid-Oxide Fuel Cell Stack

    SciTech Connect

    Chung, B W; Chervin, C N; Haslam, J J; Pham, A; Glass, R S

    2004-04-07

    A planar solid oxide fuel cell (SOFC) was fabricated using a tape-cast Ni/yttria-stabilized zirconia (YSZ) anode support, a YSZ thin film electrolyte, and a composite cathode of YSZ and (La{sub 0.85}Sr{sup 0.14}){sub 0.98}MnO{sub 3} (LSM). Using pure hydrogen as the fuel gas, a three cell stack with a cross-flow design and external manifolds produced peak power densities of 0.85 W/cm{sup 2} and 0.41 W/cm{sup 2} at 800 C and 700 C, respectively. Using wet methane as the fuel gas, the stack produced a peak power density of 0.22 W/cm{sup 2} at 700 C. Individual cells in the stack showed identical current-voltage (I -V) characteristics. Stack lifetime was limited because of degradation of the cells from oxidation products coming from the metallic interconnect used.

  4. Solvothermal synthesis of nanoporous TiO2: the impact on thin-film composite membranes for engineered osmosis application

    NASA Astrophysics Data System (ADS)

    Emadzadeh, D.; Ghanbari, M.; Lau, W. J.; Rahbari-Sisakht, M.; Matsuura, T.; Ismail, A. F.; Kruczek, B.

    2016-08-01

    In the current study, the impact of self-synthesized nanoporous titanium oxide (NT) on the morphology, performance and fouling of a polyamide (PA) thin-film composite (TFC) membrane was investigated when the membrane was applied for engineering osmosis (EO). The nanoporous structure and the spindle-like shape of NT were revealed through transmission electron microscopy (TEM), while the AATPS modification of NT was verified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results of x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) confirmed the presence of modified NT (mNT) in the PA dense active layer of the TFC membrane. The outgrowth of the ‘leaf-like’ structure, upon mNT loading, at the surface of the PA layer was observed by field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The TFC membrane prepared with 0.05 wt% mNT loading in the organic phase showed the water flux of 26.4 l m‑2 h‑1 when tested in the forward osmosis (FO) mode using 0.5M and 10 mM NaCl solution as the draw and feed solution, respectively. Moreover, the TFC-mNT membrane also demonstrated an intensified antifouling property against organic foulant during FO application and it was possible to retrieve the initial water flux almost completely with a simple water-rinsing process.

  5. Solvothermal synthesis of nanoporous TiO2: the impact on thin-film composite membranes for engineered osmosis application

    NASA Astrophysics Data System (ADS)

    Emadzadeh, D.; Ghanbari, M.; Lau, W. J.; Rahbari-Sisakht, M.; Matsuura, T.; Ismail, A. F.; Kruczek, B.

    2016-08-01

    In the current study, the impact of self-synthesized nanoporous titanium oxide (NT) on the morphology, performance and fouling of a polyamide (PA) thin-film composite (TFC) membrane was investigated when the membrane was applied for engineering osmosis (EO). The nanoporous structure and the spindle-like shape of NT were revealed through transmission electron microscopy (TEM), while the AATPS modification of NT was verified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results of x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) confirmed the presence of modified NT (mNT) in the PA dense active layer of the TFC membrane. The outgrowth of the ‘leaf-like’ structure, upon mNT loading, at the surface of the PA layer was observed by field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The TFC membrane prepared with 0.05 wt% mNT loading in the organic phase showed the water flux of 26.4 l m-2 h-1 when tested in the forward osmosis (FO) mode using 0.5M and 10 mM NaCl solution as the draw and feed solution, respectively. Moreover, the TFC-mNT membrane also demonstrated an intensified antifouling property against organic foulant during FO application and it was possible to retrieve the initial water flux almost completely with a simple water-rinsing process.

  6. Solvothermal synthesis of nanoporous TiO2: the impact on thin-film composite membranes for engineered osmosis application.

    PubMed

    Emadzadeh, D; Ghanbari, M; Lau, W J; Rahbari-Sisakht, M; Matsuura, T; Ismail, A F; Kruczek, B

    2016-08-26

    In the current study, the impact of self-synthesized nanoporous titanium oxide (NT) on the morphology, performance and fouling of a polyamide (PA) thin-film composite (TFC) membrane was investigated when the membrane was applied for engineering osmosis (EO). The nanoporous structure and the spindle-like shape of NT were revealed through transmission electron microscopy (TEM), while the AATPS modification of NT was verified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results of x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) confirmed the presence of modified NT (mNT) in the PA dense active layer of the TFC membrane. The outgrowth of the 'leaf-like' structure, upon mNT loading, at the surface of the PA layer was observed by field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The TFC membrane prepared with 0.05 wt% mNT loading in the organic phase showed the water flux of 26.4 l m(-2) h(-1) when tested in the forward osmosis (FO) mode using 0.5M and 10 mM NaCl solution as the draw and feed solution, respectively. Moreover, the TFC-mNT membrane also demonstrated an intensified antifouling property against organic foulant during FO application and it was possible to retrieve the initial water flux almost completely with a simple water-rinsing process. PMID:27405424

  7. Fabrication of Yttria stabilized zirconia thin films on poroussubstrates for fuel cell applications

    SciTech Connect

    Leming, Andres

    2003-06-16

    A process for the deposition of yttria stabilized zirconia (YSZ) films, on porous substrates, has been developed. These films have possible applications as electrolyte membranes in fuel cells. The films were deposited from colloidal suspensions through the vacuum infiltration technique. Films were deposited on both fully sintered and partially sintered substrates. A critical cracking thickness for the films was identified and strategies are presented to overcome this barrier. Green film density was also examined, and a method for improving green density by changing suspension pH and surfactant was developed. A dependence of film density on film thickness was observed, and materials interactions are suggested as a possible cause. Non-shorted YSZ films were obtained on co-fired substrates, and a cathode supported solid oxide fuel cell was constructed and characterized.

  8. Surface nanostructuring of thin film composite membranes via grafting polymerization and incorporation of ZnO nanoparticles

    NASA Astrophysics Data System (ADS)

    Isawi, Heba; El-Sayed, Magdi H.; Feng, Xianshe; Shawky, Hosam; Abdel Mottaleb, Mohamed S.

    2016-11-01

    A new approach for modification of polyamid thin film composite membrane PA(TFC) using synthesized ZnO nanoparticles (ZnO NPs) was shown to enhance the membrane performances for reverse osmosis water desalination. First, active layer of synthesis PA(TFC) membrane was activated with an aqueous solution of free radical graft polymerization of hydrophilic methacrylic acid (MAA) monomer onto the surface of the PA(TFC) membrane resulting PMAA-g-PA(TFC). Second, the PA(TFC) membrane has been developed by incorporation of ZnO NPs into the MAA grafting solution resulting the ZnO NPs modified PMAA-g-PA(TFC) membrane. The surface properties of the synthesized nanoparticles and prepared membranes were investigated using the FTIR, XRD and SEM. Morphology studies demonstrated that ZnO NPs have been successfully incorporated into the active grafting layer over PA(TFC) composite membranes. The zinc leaching from the ZnO NPs modified PMAA-g-PA(TFC) was minimal, as shown by batch tests that indicated stabilization of the ZnO NPs on the membrane surfaces. Compared with the a pure PA(TFC) and PMAA-g-PA(TFC) membranes, the ZnO NPs modified PMAA-g-PA(TFC) was more hydrophilic, with an improved water contact angle (∼50 ± 3°) over the PMAA-g-PA(TFC) (63 ± 2.5°). The ZnO NPs modified PMAA-g-PA(TFC) membrane showed salt rejection of 97% (of the total groundwater salinity), 99% of dissolved bivalent ions (Ca2+, SO42-and Mg2+), and 98% of mono valent ions constituents (Cl- and Na+). In addition, antifouling performance of the membranes was determined using E. coli as a potential foulant. This demonstrates that the ZnO NPs modified PMAA-g-PA(TFC) membrane can significantly improve the membrane performances and was favorable to enhance the selectivity, permeability, water flux, mechanical properties and the bio-antifouling properties of the membranes for water desalination.

  9. Preparation and characterization of thin-film composite membrane with nanowire-modified support for forward osmosis process.

    PubMed

    Low, Ze-Xian; Liu, Qi; Shamsaei, Ezzatollah; Zhang, Xiwang; Wang, Huanting

    2015-01-01

    Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates' properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was used as a substrate for the fabrication of TFC FO membrane, by coating a thin layer of polyamide on top of the substrate. The substrate and the nanowires were characterized by a range of techniques such as SEM, XRD, and contact angle goniometry. The water permeability and molecular weight cut-offs (MWCO) of the substrate; and the FO performance of the TFC membrane were also determined. The Zn2GeO4-modified membrane showed ~45% increase in water permeability and NaCl salt rejection of 80% under RO mode. In FO mode, the ratio of water flux to reverse solute flux was also improved. However, lower FO flux was obtained which could be due to ICP. The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP. This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance. PMID:25803239

  10. Preparation and Characterization of Thin-Film Composite Membrane with Nanowire-Modified Support for Forward Osmosis Process

    PubMed Central

    Low, Ze-Xian; Liu, Qi; Shamsaei, Ezzatollah; Zhang, Xiwang; Wang, Huanting

    2015-01-01

    Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates’ properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was used as a substrate for the fabrication of TFC FO membrane, by coating a thin layer of polyamide on top of the substrate. The substrate and the nanowires were characterized by a range of techniques such as SEM, XRD, and contact angle goniometry. The water permeability and molecular weight cut-offs (MWCO) of the substrate; and the FO performance of the TFC membrane were also determined. The Zn2GeO4-modified membrane showed ~45% increase in water permeability and NaCl salt rejection of 80% under RO mode. In FO mode, the ratio of water flux to reverse solute flux was also improved. However, lower FO flux was obtained which could be due to ICP. The result shows that Zn2GO4 nanowire may be used as a modifier to the substrate to improve the quality of the polyamide layer on the substrate to improve the flux and selectivity, but not as effective in reducing ICP. This work demonstrates that the incorporation of nanomaterials to the membrane substrate may be an alternative approach to improve the formation of polyamide skin layer to achieve better FO performance. PMID:25803239

  11. Ultra-thin film composite mixed matrix membranes incorporating iron(iii)-dopamine nanoparticles for CO2 separation

    NASA Astrophysics Data System (ADS)

    Kim, Jinguk; Fu, Qiang; Scofield, Joel M. P.; Kentish, Sandra E.; Qiao, Greg G.

    2016-04-01

    Iron dopamine nanoparticles (FeDA NPs) are incorporated into a nanoscale thick polyethylene glycol (PEG) matrix for the first time, to form ultra-thin film composite mixed matrix membranes (UTFC-MMMs) via a recently developed continuous assembly of polymers (CAP) nanotechnology. The FeDA NPs are prepared by in situ nano-complexation between Fe3+ and DA and have a particle size that can be varied from 3 to 74 nanometers by adjusting the molar ratio of DA to Fe3+ ion. The cross-linked selective layer with sub 100 nanometer thickness is prepared by atom transfer radical polymerisation of a mixture of PEG macrocross-linkers and FeDA NPs on top of a highly permeable poly(dimethyl siloxane) (PDMS) prelayer, which is spin-coated onto a porous polyacrylonitrile (PAN) substrate. The incorporation of the FeDA NPs within the PEG-based selective layer is confirmed by XPS analysis. The UTFC-MMMs (thickness: ~45 nm) formed present excellent gas separation performance with a CO2 permeance of ~1200 GPU (1 GPU = 10-6 cm3 (STP) cm-2 s-1 cmHg-1) and an enhanced CO2/N2 selectivity of over 35, which is the best performance for UTFC membranes in the reported literature.Iron dopamine nanoparticles (FeDA NPs) are incorporated into a nanoscale thick polyethylene glycol (PEG) matrix for the first time, to form ultra-thin film composite mixed matrix membranes (UTFC-MMMs) via a recently developed continuous assembly of polymers (CAP) nanotechnology. The FeDA NPs are prepared by in situ nano-complexation between Fe3+ and DA and have a particle size that can be varied from 3 to 74 nanometers by adjusting the molar ratio of DA to Fe3+ ion. The cross-linked selective layer with sub 100 nanometer thickness is prepared by atom transfer radical polymerisation of a mixture of PEG macrocross-linkers and FeDA NPs on top of a highly permeable poly(dimethyl siloxane) (PDMS) prelayer, which is spin-coated onto a porous polyacrylonitrile (PAN) substrate. The incorporation of the FeDA NPs within the PEG

  12. Ultra-thin film composite mixed matrix membranes incorporating iron(III)-dopamine nanoparticles for CO2 separation.

    PubMed

    Kim, Jinguk; Fu, Qiang; Scofield, Joel M P; Kentish, Sandra E; Qiao, Greg G

    2016-04-21

    Iron dopamine nanoparticles (FeDA NPs) are incorporated into a nanoscale thick polyethylene glycol (PEG) matrix for the first time, to form ultra-thin film composite mixed matrix membranes (UTFC-MMMs) via a recently developed continuous assembly of polymers (CAP) nanotechnology. The FeDA NPs are prepared by in situ nano-complexation between Fe(3+) and DA and have a particle size that can be varied from 3 to 74 nanometers by adjusting the molar ratio of DA to Fe(3+) ion. The cross-linked selective layer with sub 100 nanometer thickness is prepared by atom transfer radical polymerisation of a mixture of PEG macrocross-linkers and FeDA NPs on top of a highly permeable poly(dimethyl siloxane) (PDMS) prelayer, which is spin-coated onto a porous polyacrylonitrile (PAN) substrate. The incorporation of the FeDA NPs within the PEG-based selective layer is confirmed by XPS analysis. The UTFC-MMMs (thickness: ∼45 nm) formed present excellent gas separation performance with a CO2 permeance of ∼1200 GPU (1 GPU = 10(-6) cm(3) (STP) cm(-2) s(-1) cmHg(-1)) and an enhanced CO2/N2 selectivity of over 35, which is the best performance for UTFC membranes in the reported literature.

  13. Combined photocatalysis and membrane bioreactor for the treatment of feedwater containing thin film transistor-liquid crystal display discharge.

    PubMed

    You, Sheng-Jie; Semblante, Galilee Uy; Chen, Yu-Pu; Chang, Tien-Chin

    2015-01-01

    The nitrogen content of waste water generated by the thin film transistor-liquid crystal display (TFT-LCD) industry is not satisfactorily removed through the conventional aerobic-activated sludge process. In this study, the performance of three reactors – suspended type TiO2 membrane photoreactor (MPR), anoxic/oxic membrane bioreactor (AOMBR), and their combination (MPR-AOMBR) – was evaluated using feedwater containing TFT-LCD discharge. The parameters that maximized monoethanolamine (MEA) removal in the MPR were continuous ultraviolet (UV) irradiation and pH 11. Among the tested loadings, 0.1 g/l of TiO2 promoted MEA removal but degradation rate may further increase with photocatalyst concentration. The nitrified sludge recycle ratio R of the AOMBR was adjusted to 1.5 to minimize the amount of nitrate in the effluent. The AOMBR greatly decreased chemical oxygen demand and MEA, but removed only 32.7% of tetramethyl ammonium hydroxide (TMAH). The MPR was configured as the pre-treatment unit for AOMBR, and the combined MPR-AOMBR has improved TMAH removal by 80.1%. The MPR bolstered performance by decomposing slowly biodegradable compounds, and had no negative effects on denitrification and carbon removal. PMID:25952015

  14. Combined photocatalysis and membrane bioreactor for the treatment of feedwater containing thin film transistor-liquid crystal display discharge.

    PubMed

    You, Sheng-Jie; Semblante, Galilee Uy; Chen, Yu-Pu; Chang, Tien-Chin

    2015-01-01

    The nitrogen content of waste water generated by the thin film transistor-liquid crystal display (TFT-LCD) industry is not satisfactorily removed through the conventional aerobic-activated sludge process. In this study, the performance of three reactors – suspended type TiO2 membrane photoreactor (MPR), anoxic/oxic membrane bioreactor (AOMBR), and their combination (MPR-AOMBR) – was evaluated using feedwater containing TFT-LCD discharge. The parameters that maximized monoethanolamine (MEA) removal in the MPR were continuous ultraviolet (UV) irradiation and pH 11. Among the tested loadings, 0.1 g/l of TiO2 promoted MEA removal but degradation rate may further increase with photocatalyst concentration. The nitrified sludge recycle ratio R of the AOMBR was adjusted to 1.5 to minimize the amount of nitrate in the effluent. The AOMBR greatly decreased chemical oxygen demand and MEA, but removed only 32.7% of tetramethyl ammonium hydroxide (TMAH). The MPR was configured as the pre-treatment unit for AOMBR, and the combined MPR-AOMBR has improved TMAH removal by 80.1%. The MPR bolstered performance by decomposing slowly biodegradable compounds, and had no negative effects on denitrification and carbon removal.

  15. CVD of polymeric thin films: applications in sensors, biotechnology, microelectronics/organic electronics, microfluidics, MEMS, composites and membranes

    NASA Astrophysics Data System (ADS)

    Ozaydin-Ince, Gozde; Coclite, Anna Maria; Gleason, Karen K.

    2012-01-01

    Polymers with their tunable functionalities offer the ability to rationally design micro- and nano-engineered materials. Their synthesis as thin films have significant advantages due to the reduced amounts of materials used, faster processing times and the ability to modify the surface while preserving the structural properties of the bulk. Furthermore, their low cost, ease of fabrication and the ability to be easily integrated into processing lines, make them attractive alternatives to their inorganic thin film counterparts. Chemical vapor deposition (CVD) as a polymer thin-film deposition technique offers a versatile platform for fabrication of a wide range of polymer thin films preserving all the functionalities. Solventless, vapor-phase deposition enable the integration of polymer thin films or nanostructures into micro- and nanodevices for improved performance. In this review, CVD of functional polymer thin films and the polymerization mechanisms are introduced. The properties of the polymer thin films that determine their behavior are discussed and their technological advances and applications are reviewed.

  16. Ion-exchange funneling in thin-film coating modification of heterogeneous electrodialysis membranes.

    PubMed

    Rubinstein, Isaak; Zaltzman, Boris; Pundik, Tamara

    2002-04-01

    Inexpensive highly permselective heterogeneous ion-exchange membranes are prohibitively highly polarizable by a dc current for being used in electrodialysis. According to recent experiments, polarizability of these membranes may be considerably reduced by casting on their surface a thin layer of crosslinked polyelectrolyte, slightly charged with the same sign as the membrane's charge. The present paper is concerned with this effect. Concentration polarization of a permselective heterogeneous ion-exchange membrane by a dc current is determined by geometric factors, such as, the typical size of the ion-permeable "gates" at the membrane surface relative to the separation distance between them and the diffusion layer thickness. The main quantitative characteristic of polarizability of a heterogeneous membrane is its voltage/current curve with its typical saturation at the limiting current, which is lower than that for a homogeneous membrane. In the present study we modify the previously developed two-dimensional model of ionic transport in a diffusion layer at a heterogeneous ion-exchange membrane by including into consideration a homogeneous ion-exchange layer adjacent to the membrane surface. A numerical solution of the respective boundary value problem shows that, indeed, adding even a very thin and weakly charged layer of this kind increases the value of the limiting current, to that of a homogeneous membrane. What differs, for different values of coating parameters, is the form of the voltage/current curves but not the value of the limiting current, namely: the thinner is the coating and the lower the fixed charge density in it, the "slower" is the approach of the limiting current. In order to explain this feature, a simple limiting model of modified membrane is derived from the original two-layer model. In this limiting model, asymptotically valid for a thin coating, solution of the ionic transport equations in it is replaced, via a suitable averaging procedure

  17. Inkjet-Printed Porous Silver Thin Film as a Cathode for a Low-Temperature Solid Oxide Fuel Cell.

    PubMed

    Yu, Chen-Chiang; Baek, Jong Dae; Su, Chun-Hao; Fan, Liangdong; Wei, Jun; Liao, Ying-Chih; Su, Pei-Chen

    2016-04-27

    In this work we report a porous silver thin film cathode that was fabricated by a simple inkjet printing process for low-temperature solid oxide fuel cell applications. The electrochemical performance of the inkjet-printed silver cathode was studied at 300-450 °C and was compared with that of silver cathodes that were fabricated by the typical sputtering method. Inkjet-printed silver cathodes showed lower electrochemical impedance due to their porous structure, which facilitated oxygen gaseous diffusion and oxygen surface adsorption-dissociation reactions. A typical sputtered nanoporous silver cathode became essentially dense after the operation and showed high impedance due to a lack of oxygen supply. The results of long-term fuel cell operation show that the cell with an inkjet-printed cathode had a more stable current output for more than 45 h at 400 °C. A porous silver cathode is required for high fuel cell performance, and the simple inkjet printing technique offers an alternative method of fabrication for such a desirable porous structure with the required thermal-morphological stability.

  18. Inkjet-Printed Porous Silver Thin Film as a Cathode for a Low-Temperature Solid Oxide Fuel Cell.

    PubMed

    Yu, Chen-Chiang; Baek, Jong Dae; Su, Chun-Hao; Fan, Liangdong; Wei, Jun; Liao, Ying-Chih; Su, Pei-Chen

    2016-04-27

    In this work we report a porous silver thin film cathode that was fabricated by a simple inkjet printing process for low-temperature solid oxide fuel cell applications. The electrochemical performance of the inkjet-printed silver cathode was studied at 300-450 °C and was compared with that of silver cathodes that were fabricated by the typical sputtering method. Inkjet-printed silver cathodes showed lower electrochemical impedance due to their porous structure, which facilitated oxygen gaseous diffusion and oxygen surface adsorption-dissociation reactions. A typical sputtered nanoporous silver cathode became essentially dense after the operation and showed high impedance due to a lack of oxygen supply. The results of long-term fuel cell operation show that the cell with an inkjet-printed cathode had a more stable current output for more than 45 h at 400 °C. A porous silver cathode is required for high fuel cell performance, and the simple inkjet printing technique offers an alternative method of fabrication for such a desirable porous structure with the required thermal-morphological stability. PMID:27045453

  19. Scalable nanostructured membranes for solid-oxide fuel cells.

    PubMed

    Tsuchiya, Masaru; Lai, Bo-Kuai; Ramanathan, Shriram

    2011-05-01

    The use of oxide fuel cells and other solid-state ionic devices in energy applications is limited by their requirement for elevated operating temperatures, typically above 800°C (ref. 1). Thin-film membranes allow low-temperature operation by reducing the ohmic resistance of the electrolytes. However, although proof-of-concept thin-film devices have been demonstrated, scaling up remains a significant challenge because large-area membranes less than ~ 100 nm thick are susceptible to mechanical failure. Here, we report that nanoscale yttria-stabilized zirconia membranes with lateral dimensions on the scale of millimetres or centimetres can be made thermomechanically stable by depositing metallic grids on them to function as mechanical supports. We combine such a membrane with a nanostructured dense oxide cathode to make a thin-film solid-oxide fuel cell that can achieve a power density of 155 mW cm⁻² at 510 °C. We also report a total power output of more than 20 mW from a single fuel-cell chip. Our large-area membranes could also be relevant to electrochemical energy applications such as gas separation, hydrogen production and permeation membranes.

  20. Scalable nanostructured membranes for solid-oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Masaru; Lai, Bo-Kuai; Ramanathan, Shriram

    2011-05-01

    The use of oxide fuel cells and other solid-state ionic devices in energy applications is limited by their requirement for elevated operating temperatures, typically above 800 °C (ref. 1). Thin-film membranes allow low-temperature operation by reducing the ohmic resistance of the electrolytes. However, although proof-of-concept thin-film devices have been demonstrated, scaling up remains a significant challenge because large-area membranes less than ~100 nm thick are susceptible to mechanical failure. Here, we report that nanoscale yttria-stabilized zirconia membranes with lateral dimensions on the scale of millimetres or centimetres can be made thermomechanically stable by depositing metallic grids on them to function as mechanical supports. We combine such a membrane with a nanostructured dense oxide cathode to make a thin-film solid-oxide fuel cell that can achieve a power density of 155 mW cm-2 at 510 °C. We also report a total power output of more than 20 mW from a single fuel-cell chip. Our large-area membranes could also be relevant to electrochemical energy applications such as gas separation, hydrogen production and permeation membranes.

  1. Thin films and assemblies of photosensitive membrane proteins and colloidal nanocrystals for engineering of hybrid materials with advanced properties.

    PubMed

    Zaitsev, Sergei Yu; Solovyeva, Daria O; Nabiev, Igor

    2012-11-15

    The development and study of nano-bio hybrid materials engineered from membrane proteins (the key functional elements of various biomembranes) and nanoheterostructures (inorganic colloidal nanoparticles, transparent electrodes, and films) is a rapidly growing field at the interface of materials and life sciences. The mainspring of the development of bioinspired materials and devices is the fact that biological evolution has solved many problems similar to those that humans are attempting to solve in the field of light-harvesting and energy-transferring inorganic compounds. Along this way, bioelectronics and biophotonics have shown considerable promise. A number of proteins have been explored in terms of bioelectronic device applications, but bacteriorhodopsin (bR, a photosensitive membrane protein from purple membranes of the bacterium Halobacterium salinarum) and bacterial photosynthetic reaction centres have received the most attention. The energy harvesting in plants has a maximum efficiency of 5%, whereas bR, in the absence of a specific light-harvesting system, allows bacteria to utilize only 0.1-0.5% of the solar light. Recent nano-bioengineering approaches employing colloidal semiconductor and metal nanoparticles conjugated with biosystems permit the enhancement of the light-harvesting capacity of photosensitive proteins, thus providing a strong impetus to protein-based device optimisation. Fabrication of ultrathin and highly oriented films from biological membranes and photosensitive proteins is the key task for prospective bioelectronic and biophotonic applications. In this review, the main advances in techniques of preparation of such films are analyzed. Comparison of the techniques for obtaining thin films leads to the conclusion that the homogeneity and orientation of biomembrane fragments or proteins in these films depend on the method of their fabrication and increase in the following order: electrophoretic sedimentation < Langmuir-Blodgett and

  2. Geometrically Nonlinear Shell Analysis of Wrinkled Thin-Film Membranes with Stress Concentrations

    NASA Technical Reports Server (NTRS)

    Tessler, Alexander; Sleight, David W.

    2006-01-01

    Geometrically nonlinear shell finite element analysis has recently been applied to solar-sail membrane problems in order to model the out-of-plane deformations due to structural wrinkling. Whereas certain problems lend themselves to achieving converged nonlinear solutions that compare favorably with experimental observations, solutions to tensioned membranes exhibiting high stress concentrations have been difficult to obtain even with the best nonlinear finite element codes and advanced shell element technology. In this paper, two numerical studies are presented that pave the way to improving the modeling of this class of nonlinear problems. The studies address the issues of mesh refinement and stress-concentration alleviation, and the effects of these modeling strategies on the ability to attain converged nonlinear deformations due to wrinkling. The numerical studies demonstrate that excessive mesh refinement in the regions of stress concentration may be disadvantageous to achieving wrinkled equilibrium states, causing the nonlinear solution to lock in the membrane response mode, while totally discarding the very low-energy bending response that is necessary to cause wrinkling deformation patterns.

  3. Development of thin-film composite forward osmosis hollow fiber membranes using direct sulfonated polyphenylenesulfone (sPPSU) as membrane substrates.

    PubMed

    Zhong, Peishan; Fu, Xiuzhu; Chung, Tai-Shung; Weber, Martin; Maletzko, Christian

    2013-07-01

    This study investigates a new approach to fabricate thin-film composite (TFC) hollow fiber membranes via interfacial polymerization for forward osmosis (FO) applications. Different degrees of sulfonation of polyphenylenesulfone (PPSU) were adopted as membrane substrates to investigate their impact on water flux. It has been established that the degree of sulfonation plays a role in both creating a macrovoid-free structure and inducing hydrophilicity to bring about higher water fluxes. The fabricated membranes exhibit extremely high water fluxes of 30.6 and 82.0 LMH against a pure water feed using 2.0 M NaCl as the draw solution tested under FO and pressure retarded osmosis (PRO) modes, respectively, while maintaining low salt reverse fluxes below 12.7 gMH. The structural parameter (S) displays remarkable decreases of up to 4.5 times as the membrane substrate is switched from a nonsulfonated to sulfonated one. In addition, the newly developed TFC-FO membranes containing 1.5 mol % sPPSU in the substrate achieves a water flux of 22 LMH in seawater desalination using a 3.5 wt % NaCl model solution and 2.0 M NaCl as the draw solution under the PRO mode. To the best of our knowledge, this value is the highest ever reported for seawater desalination using flat and hollow fiber FO membranes. The use of sulfonated materials in the FO process opens up a frontier for sustainable and efficient production of potable water.

  4. Pyrolyzed thin film carbon

    NASA Technical Reports Server (NTRS)

    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.

  5. Selective inorganic thin films

    SciTech Connect

    Phillips, M.L.F.; Weisenbach, L.A.; Anderson, M.T.

    1995-05-01

    This project is developing inorganic thin films as membranes for gas separation applications, and as discriminating coatings for liquid-phase chemical sensors. Our goal is to synthesize these coatings with tailored porosity and surface chemistry on porous substrates and on acoustic and optical sensors. Molecular sieve films offer the possibility of performing separations involving hydrogen, air, and natural gas constituents at elevated temperatures with very high separation factors. We are focusing on improving permeability and molecular sieve properties of crystalline zeolitic membranes made by hydrothermally reacting layered multicomponent sol-gel films deposited on mesoporous substrates. We also used acoustic plate mode (APM) oscillator and surface plasmon resonance (SPR) sensor elements as substrates for sol-gel films, and have both used these modified sensors to determine physical properties of the films and have determined the sensitivity and selectivity of these sensors to aqueous chemical species.

  6. Laser ablation for membrane processing of AlGaN/GaN- and micro structured ferroelectric thin film MEMS and SiC pressure sensors for extreme conditions

    NASA Astrophysics Data System (ADS)

    Zehetner, J.; Vanko, G.; Dzuba, J.; Ryger, I.; Lalinsky, T.; Benkler, Manuel; Lucki, Michal

    2015-05-01

    AlGaN/GaN based high electron mobility transistors (HEMTs), Schottky diodes and/or resistors have been presented as sensing devices for mechanical or chemical sensors operating in extreme conditions. In addition we investigate ferroelectric thin films for integration into micro-electro-mechanical-systems (MEMS). Creation of appropriate diaphragms and/or cantilevers out of SiC is necessary for further improvement of sensing properties of such MEMS sensors. For example sensitivity of the AlGaN/GaN based MEMS pressure sensor can be modified by membrane thickness. We demonstrated that a 4H-SiC 80μm thick diaphragms can be fabricated much faster with laser ablation than by electrochemical, photochemical or reactive ion etching (RIE). We were able to verify the feasibility of this process by fabrication of micromechanical membrane structures also in bulk 3C-SiC, borosilicate glass, sapphire and Al2O3 ceramic substrates by femtosecond laser (520nm) ablation. On a 350μm thick 4H-SiC substrate we produced an array of 275μm deep and 1000μm to 3000μm of diameter blind holes without damaging the 2μm AlN layer at the back side. In addition we investigated ferroelectric thin films as they can be deposited and micro-patterned by a direct UV-lithography method after the ablation process for a specific membrane design. The risk to harm or damage the function of thin films was eliminated by that means. Some defects in the ablated membranes are also affected by the polarisation of the laser light. Ripple structures oriented perpendicular to the laser polarisation promote creation of pin holes which would perforate a thin membrane. We developed an ablation technique strongly inhibiting formation of ripples and pin poles.

  7. Growth dynamics, charge density, and structure of polyamide thin-film composite membranes

    NASA Astrophysics Data System (ADS)

    Matthews, Tamlin

    between 0.1 g/L TMC and 10 g/L TMC. The near-surface charge density also increases with increasing TMC concentration. Charge density was determined in the bulk RBS on membranes at varying pH between 3.5 and 10.5. These membranes show a good fit to a two pKa system, except the highest TMC concentration studied of 5 g/L which followed a one pKa system. Fitting the pH data using the pKa system shows that the total concentration of carboxylic acid groups decreases from 0.42 to 0.20 M with increasing MPD concentration. The decreasing carboxylic acid content is due to a higher concentration of MPD monomers. The total concentration of carboxylic acid groups increases with from 0.05 to 0.51 M with increasing TMC concentration. The concentration of TMC has a large effect on the charge density with the highest pH of 10.5 resulting in the highest measured charge density for each concentration increasing from 0.04 M to 0.55 M for 0.1 g/L to 5 g/L TMC. Grazing incidence small- and wide-angle X-ray scattering (GISAXS and GIWAXS) were successfully used to study the supported polysulfone ultrafiltration membrane and polyamide on polysulfone reverse osmosis membrane. Linear regions in GISAXS of I(Q) alpha Q-3.7 for polysulfone and Q -3.6 for polyamide on polysulfone were observed, which correspond to the Porod regime for smooth internal polymer interface sizes between 392.7 nm < d < 523.6 nm. The size of the interface is larger for higher incidence angles, which penetrate deeper into the porous structure of polysulfone. (Abstract shortened by UMI.).

  8. Novel approaches for fabrication of thin film layers for solid oxide electrolyte fuel cells

    NASA Technical Reports Server (NTRS)

    Murugesamoorthi, K. A.; Srinivasan, S.; Cocke, D. L.; Appleby, A. J.

    1990-01-01

    The main objectives of the SOFC (solid oxide fuel cell) project are to (1) identify viable and cost-effective techniques to prepare cell components for stable MSOFCs (monolithic SOFCs); (2) fabricate half and single cells; and (3) evaluate their performances. The approach used to fabricate stable MSOFCs is as follows: (1) the electrolyte layer is prepared in the form of a honeycomb structure by alloy oxidation and other cell components are deposited on it; (2) the electrolyte and anode layers are deposited on the cathode layer, which has a porous, honeycomb structure; and (3) the electrolyte and cathode layers are deposited on the anode layer. The current status of the project is reported.

  9. Atomic Layer Deposited Thin Films for Dielectrics, Semiconductor Passivation, and Solid Oxide Fuel Cells

    NASA Astrophysics Data System (ADS)

    Xu, Runshen

    Atomic layer deposition (ALD) utilizes sequential precursor gas pulses to deposit one monolayer or sub-monolayer of material per cycle based on its self-limiting surface reaction, which offers advantages, such as precise thickness control, thickness uniformity, and conformality. ALD is a powerful means of fabricating nanoscale features in future nanoelectronics, such as contemporary sub-45 nm metal-oxide-semiconductor field effect transistors, photovoltaic cells, near- and far-infrared detectors, and intermediate temperature solid oxide fuel cells. High dielectric constant, kappa, materials have been recognized to be promising candidates to replace traditional SiO2 and SiON, because they enable good scalability of sub-45 nm MOSFET (metal-oxide-semiconductor field-effect transistor) without inducing additional power consumption and heat dissipation. In addition to high dielectric constant, high-kappa materials must meet a number of other requirements, such as low leakage current, high mobility, good thermal and structure stability with Si to withstand high-temperature source-drain activation annealing. In this thesis, atomic layer deposited Er2O3 doped TiO2 is studied and proposed as a thermally stable amorphous high-kappa dielectric on Si substrate. The stabilization of TiO2 in its amorphous state is found to achieve a high permittivity of 36, a hysteresis voltage of less than 10 mV, and a low leakage current density of 10-8 A/cm-2 at -1 MV/cm. In III-V semiconductors, issues including unsatisfied dangling bonds and native oxides often result in inferior surface quality that yields non-negligible leakage currents and degrades the long-term performance of devices. The traditional means for passivating the surface of III-V semiconductors are based on the use of sulfide solutions; however, that only offers good protection against oxidation for a short-term (i.e., one day). In this work, in order to improve the chemical passivation efficacy of III-V semiconductors

  10. Zeolite thin films: from computer chips to space stations.

    PubMed

    Lew, Christopher M; Cai, Rui; Yan, Yushan

    2010-02-16

    more recent work on polycrystalline zeolite thin films as promising biocompatible coatings and environmentally benign wear-resistant and antifouling coatings. When zeolites are incorporated into polymer thin films in the form of nanocrystals, we also show that the resultant composite membranes can significantly improve the performance of reverse osmosis membranes for sea water desalination and proton exchange membrane fuel cells. These diverse applications of zeolites have the potential to initiate new industries while revolutionizing existing ones with a potential economic impact that could extend into the hundreds of billions of dollars. We have licensed several of these inventions to companies with millions of dollars invested in their commercial development. We expect that other related technologies will be licensed in the near future. PMID:20158246

  11. Zeolite thin films: from computer chips to space stations.

    PubMed

    Lew, Christopher M; Cai, Rui; Yan, Yushan

    2010-02-16

    more recent work on polycrystalline zeolite thin films as promising biocompatible coatings and environmentally benign wear-resistant and antifouling coatings. When zeolites are incorporated into polymer thin films in the form of nanocrystals, we also show that the resultant composite membranes can significantly improve the performance of reverse osmosis membranes for sea water desalination and proton exchange membrane fuel cells. These diverse applications of zeolites have the potential to initiate new industries while revolutionizing existing ones with a potential economic impact that could extend into the hundreds of billions of dollars. We have licensed several of these inventions to companies with millions of dollars invested in their commercial development. We expect that other related technologies will be licensed in the near future.

  12. Highly robust thin-film composite pressure retarded osmosis (PRO) hollow fiber membranes with high power densities for renewable salinity-gradient energy generation.

    PubMed

    Han, Gang; Wang, Peng; Chung, Tai-Shung

    2013-07-16

    The practical application of pressure retarded osmosis (PRO) technology for renewable blue energy (i.e., osmotic power generation) from salinity gradient is being hindered by the absence of effective membranes. Compared to flat-sheet membranes, membranes with a hollow fiber configuration are of great interest due to their high packing density and spacer-free module fabrication. However, the development of PRO hollow fiber membranes is still in its infancy. This study aims to open up new perspectives and design strategies to molecularly construct highly robust thin film composite (TFC) PRO hollow fiber membranes with high power densities. The newly developed TFC PRO membranes consist of a selective polyamide skin formed on the lumen side of well-constructed Matrimid hollow fiber supports via interfacial polymerization. For the first time, laboratory PRO power generation tests demonstrate that the newly developed PRO hollow fiber membranes can withstand trans-membrane pressures up to 16 bar and exhibit a peak power density as high as 14 W/m(2) using seawater brine (1.0 M NaCl) as the draw solution and deionized water as the feed. We believe that the developed TFC PRO hollow fiber membranes have great potential for osmotic power harvesting.

  13. Highly robust thin-film composite pressure retarded osmosis (PRO) hollow fiber membranes with high power densities for renewable salinity-gradient energy generation.

    PubMed

    Han, Gang; Wang, Peng; Chung, Tai-Shung

    2013-07-16

    The practical application of pressure retarded osmosis (PRO) technology for renewable blue energy (i.e., osmotic power generation) from salinity gradient is being hindered by the absence of effective membranes. Compared to flat-sheet membranes, membranes with a hollow fiber configuration are of great interest due to their high packing density and spacer-free module fabrication. However, the development of PRO hollow fiber membranes is still in its infancy. This study aims to open up new perspectives and design strategies to molecularly construct highly robust thin film composite (TFC) PRO hollow fiber membranes with high power densities. The newly developed TFC PRO membranes consist of a selective polyamide skin formed on the lumen side of well-constructed Matrimid hollow fiber supports via interfacial polymerization. For the first time, laboratory PRO power generation tests demonstrate that the newly developed PRO hollow fiber membranes can withstand trans-membrane pressures up to 16 bar and exhibit a peak power density as high as 14 W/m(2) using seawater brine (1.0 M NaCl) as the draw solution and deionized water as the feed. We believe that the developed TFC PRO hollow fiber membranes have great potential for osmotic power harvesting. PMID:23772898

  14. Controlled Architecture of Dual-Functional Block Copolymer Brushes on Thin-Film Composite Membranes for Integrated "Defending" and "Attacking" Strategies against Biofouling.

    PubMed

    Ye, Gang; Lee, Jongho; Perreault, François; Elimelech, Menachem

    2015-10-21

    We report a new macromolecular architecture of dual functional block copolymer brushes on commercial thin-film composite (TFC) membranes for integrated "defending" and "attacking" strategies against biofouling. Mussel-inspired catechol chemistry is used for a convenient immobilization of initiator molecules to the membrane surface with the aid of polydopamine (PDA). Zwitterionic polymer brushes with strong hydration capacity and quaternary ammonium salt (QAS) polymer brushes with bactericidal ability are sequentially grafted on TFC membranes via activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP), an environmentally benign and controlled polymerization method. Measurement of membrane intrinsic transport properties in reverse osmosis experiments shows that the modified TFC membrane maintains the same water permeability and salt selectivity as the pristine TFC membrane. Chemical force microscopy and protein/bacterial adhesion studies are carried out for a comprehensive evaluation of the biofouling resistance and antimicrobial ability, demonstrating low biofouling propensity and excellent bacterial inactivation for the modified TFC membrane. We conclude that this polymer architecture, with complementary "defending" and "attacking" capabilities, can effectively prevent the attachment of biofoulants and formation of biofilms and thereby significantly mitigate biofouling on TFC membranes. PMID:26378606

  15. Controlled Architecture of Dual-Functional Block Copolymer Brushes on Thin-Film Composite Membranes for Integrated "Defending" and "Attacking" Strategies against Biofouling.

    PubMed

    Ye, Gang; Lee, Jongho; Perreault, François; Elimelech, Menachem

    2015-10-21

    We report a new macromolecular architecture of dual functional block copolymer brushes on commercial thin-film composite (TFC) membranes for integrated "defending" and "attacking" strategies against biofouling. Mussel-inspired catechol chemistry is used for a convenient immobilization of initiator molecules to the membrane surface with the aid of polydopamine (PDA). Zwitterionic polymer brushes with strong hydration capacity and quaternary ammonium salt (QAS) polymer brushes with bactericidal ability are sequentially grafted on TFC membranes via activators regenerated by electron transfer-atom transfer radical polymerization (ARGET-ATRP), an environmentally benign and controlled polymerization method. Measurement of membrane intrinsic transport properties in reverse osmosis experiments shows that the modified TFC membrane maintains the same water permeability and salt selectivity as the pristine TFC membrane. Chemical force microscopy and protein/bacterial adhesion studies are carried out for a comprehensive evaluation of the biofouling resistance and antimicrobial ability, demonstrating low biofouling propensity and excellent bacterial inactivation for the modified TFC membrane. We conclude that this polymer architecture, with complementary "defending" and "attacking" capabilities, can effectively prevent the attachment of biofoulants and formation of biofilms and thereby significantly mitigate biofouling on TFC membranes.

  16. Cobalt-free polycrystalline Ba0.95La0.05FeO3-δ thin films as cathodes for intermediate-temperature solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Chen, Dengjie; Chen, Chi; Dong, Feifei; Shao, Zongping; Ciucci, Francesco

    2014-03-01

    Ba0.95La0.05FeO3-δ (BLF) thin films as electrodes for intermediate-temperature solid oxide fuel cells are prepared on single-crystal yttria-stabilized zirconia (YSZ) substrates by pulsed laser deposition. The phase structure, surface morphology and roughness of the BLF thin films are characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy. X-ray photoelectron spectroscopy is used to analyze the compositions of the deposited thin film and the chemical state of transition metal. The dense thin film exhibits a polycrystalline perovskite structure with a low surface roughness and a high oxygen vacancy concentration on the surface. Ag (paste or strip) and Au (strip) are applied on both surfaces of the symmetric cells as current collectors to evaluate electrochemical performance of the thin films. The electrode polarization resistances of the symmetric cells are found to be lower than those of most cobalt-free thin-film electrodes, e.g., 0.437 Ω cm2 at 700 °C and 0.21 atm. The oxygen reduction reaction mechanism of the BLF cathode in symmetric cells is studied by electrochemical impedance spectroscopy thanks to the equivalent fitting analysis. Both the oxygen surface exchange reaction and charge transfer are shown to determine the overall oxygen reduction reaction.

  17. Preparation and pre-characterization of epoxidized natural rubber (ENR) / poly(vinylidene fluoride) (PVDF) (ENR/PVDF) thin film composite membrane

    NASA Astrophysics Data System (ADS)

    Mod, Norliyana; Othaman, Rizafizah

    2015-09-01

    Epoxidised Natural Rubber (ENR) / Poly (Vinylidene Fluoride) (PVDF) (ENR/PVDF) (60:40 wt%) thin film composite membrane was prepared by using solution casting technique. The focuses of this paper are to prepare ENR/PVDF membrane with ratio of ENR to PVDF 60:40 wt%, and to study the effectiveness of treating Palm Oil Mill Effluent (POME) using the membrane. The prepared membrane was analyzed using optical microscope and the treatment of POME was investigated using dead-end stirred cell. Treated and untreated POME was analyzed to test the percentage of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) removal. Optical microscope micrographs showed that the surface of the membrane was slightly uneven. The rate of flux which passed through the membrane was 0.60 L/hm2. Both BOD and COD decreased by 23.6 % and 49.32 % respectively, after single treatment. This showed that the membrane can be used for POME treatment. The value of BOD and COD removal can be increased by recycling the treated POME for more than two cycles, which will be further studied by authors.

  18. Thin film hydrogen sensor

    DOEpatents

    Cheng, Y.T.; Poli, A.A.; Meltser, M.A.

    1999-03-23

    A thin film hydrogen sensor includes a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end. 5 figs.

  19. Thin film hydrogen sensor

    DOEpatents

    Cheng, Yang-Tse; Poli, Andrea A.; Meltser, Mark Alexander

    1999-01-01

    A thin film hydrogen sensor, includes: a substantially flat ceramic substrate with first and second planar sides and a first substrate end opposite a second substrate end; a thin film temperature responsive resistor on the first planar side of the substrate proximate to the first substrate end; a thin film hydrogen responsive metal resistor on the first planar side of the substrate proximate to the fist substrate end and proximate to the temperature responsive resistor; and a heater on the second planar side of the substrate proximate to the first end.

  20. Biomimetic thin film synthesis

    SciTech Connect

    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.

  1. Composite fuel cell membranes

    DOEpatents

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  2. Composite fuel cell membranes

    DOEpatents

    Plowman, K.R.; Rehg, T.J.; Davis, L.W.; Carl, W.P.; Cisar, A.J.; Eastland, C.S.

    1997-08-05

    A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  3. Development of advanced catalytic layer based on vertically aligned conductive polymer arrays for thin-film fuel cell electrodes

    NASA Astrophysics Data System (ADS)

    Jiang, Shangfeng; Yi, Baolian; Cao, Longsheng; Song, Wei; Zhao, Qing; Yu, Hongmei; Shao, Zhigang

    2016-10-01

    The degradation of carbon supports significantly influences the performance of proton exchange membrane fuel cells (PEMFCs), particularly in the cathode, which must be overcome for the wide application of fuel cells. In this study, advanced catalytic layer with electronic conductive polymer-polypyrrole (PPy) nanowire as ordered catalyst supports for PEMFCs is prepared. A platinum-palladium (PtPd) catalyst thin layer with whiskerette shapes forms along the long axis of the PPy nanowires. The resulting arrays are hot-pressed on both sides of a Nafion® membrane to construct a membrane electrode assembly (without additional ionomer). The ordered thin catalyst layer (approximately 1.1 μm) is applied in a single cell as the anode and the cathode without additional Nafion® ionomer. The single cell yields a maximum performance of 762.1 mW cm-2 with a low Pt loading (0.241 mg Pt cm-2, anode + cathode). The advanced catalyst layer indicates better mass transfer in high current density than that of commercial Pt/C-based electrode. The mass activity is 1.08-fold greater than that of DOE 2017 target. Thus, the as-prepared electrodes have the potential for application in fuel cells.

  4. High performance thin-film composite forward osmosis hollow fiber membranes with macrovoid-free and highly porous structure for sustainable water production.

    PubMed

    Sukitpaneenit, Panu; Chung, Tai-Shung

    2012-07-01

    The development of high-performance and well-constructed thin-film composite (TFC) hollow fiber membranes for forward osmosis (FO) applications is presented in this study. The newly developed membranes consist of a functional selective polyamide layer formed by highly reproducible interfacial polymerization on a polyethersulfone (PES) hollow fiber support. Using dual-layer coextrusion technology to design and effectively control the phase inversion during membrane formation, the support was designed to possess desirable macrovoid-free and fully sponge-like morphology. Such morphology not only provides excellent membrane strength, but it has been proven to minimize internal concentration polarization in a FO process, thus leading to the water flux enhancement. The fabricated membranes exhibited relatively high water fluxes of 32-34 LMH and up to 57-65 LMH against a pure water feed using 2 M NaCl as the draw solution tested under the FO and pressure retarded osmosis (PRO) modes, respectively, while consistently maintaining relatively low salt leakages below 13 gMH for all cases. With model seawater solution as the feed, the membranes could display a high water flux up to 15-18 LMH, which is comparable to the best value reported for seawater desalination applications.

  5. High performance thin-film composite forward osmosis hollow fiber membranes with macrovoid-free and highly porous structure for sustainable water production.

    PubMed

    Sukitpaneenit, Panu; Chung, Tai-Shung

    2012-07-01

    The development of high-performance and well-constructed thin-film composite (TFC) hollow fiber membranes for forward osmosis (FO) applications is presented in this study. The newly developed membranes consist of a functional selective polyamide layer formed by highly reproducible interfacial polymerization on a polyethersulfone (PES) hollow fiber support. Using dual-layer coextrusion technology to design and effectively control the phase inversion during membrane formation, the support was designed to possess desirable macrovoid-free and fully sponge-like morphology. Such morphology not only provides excellent membrane strength, but it has been proven to minimize internal concentration polarization in a FO process, thus leading to the water flux enhancement. The fabricated membranes exhibited relatively high water fluxes of 32-34 LMH and up to 57-65 LMH against a pure water feed using 2 M NaCl as the draw solution tested under the FO and pressure retarded osmosis (PRO) modes, respectively, while consistently maintaining relatively low salt leakages below 13 gMH for all cases. With model seawater solution as the feed, the membranes could display a high water flux up to 15-18 LMH, which is comparable to the best value reported for seawater desalination applications. PMID:22663085

  6. Ceramic Composite Thin Films

    NASA Technical Reports Server (NTRS)

    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.

  7. Influence of active layer and support layer surface structures on organic fouling propensity of thin-film composite forward osmosis membranes.

    PubMed

    Lu, Xinglin; Arias Chavez, Laura H; Romero-Vargas Castrillón, Santiago; Ma, Jun; Elimelech, Menachem

    2015-02-01

    In this study, we investigate the influence of surface structure on the fouling propensity of thin-film composite (TFC) forward osmosis (FO) membranes. Specifically, we compare membranes fabricated through identical procedures except for the use of different solvents (dimethylformamide, DMF and N-methyl-2-pyrrolidinone, NMP) during phase separation. FO fouling experiments were carried out with a feed solution containing a model organic foulant. The TFC membranes fabricated using NMP (NMP-TFC) had significantly less flux decline (7.47 ± 0.15%) when compared to the membranes fabricated using DMF (DMF-TFC, 12.70 ± 2.62% flux decline). Water flux was also more easily recovered through physical cleaning for the NMP-TFC membrane. To determine the fundamental cause of these differences in fouling propensity, the active and support layers of the membranes were extensively characterized for physical and chemical characteristics relevant to fouling behavior. Polyamide surface roughness was found to dominate all other investigated factors in determining the fouling propensities of our membranes relative to each other. The high roughness polyamide surface of the DMF-TFC membrane was also rich in larger leaf-like structures, whereas the lower roughness NMP-TFC membrane polyamide layer contained more nodular and smaller features. The support layers of the two membrane types were also characterized for their morphological properties, and the relation between support layer surface structure and polyamide active layer formation was discussed. Taken together, our findings indicate that support layer structure has a significant impact on the fouling propensity of the active layer, and this impact should be considered in the design of support layer structures for TFC membranes.

  8. Influence of active layer and support layer surface structures on organic fouling propensity of thin-film composite forward osmosis membranes.

    PubMed

    Lu, Xinglin; Arias Chavez, Laura H; Romero-Vargas Castrillón, Santiago; Ma, Jun; Elimelech, Menachem

    2015-02-01

    In this study, we investigate the influence of surface structure on the fouling propensity of thin-film composite (TFC) forward osmosis (FO) membranes. Specifically, we compare membranes fabricated through identical procedures except for the use of different solvents (dimethylformamide, DMF and N-methyl-2-pyrrolidinone, NMP) during phase separation. FO fouling experiments were carried out with a feed solution containing a model organic foulant. The TFC membranes fabricated using NMP (NMP-TFC) had significantly less flux decline (7.47 ± 0.15%) when compared to the membranes fabricated using DMF (DMF-TFC, 12.70 ± 2.62% flux decline). Water flux was also more easily recovered through physical cleaning for the NMP-TFC membrane. To determine the fundamental cause of these differences in fouling propensity, the active and support layers of the membranes were extensively characterized for physical and chemical characteristics relevant to fouling behavior. Polyamide surface roughness was found to dominate all other investigated factors in determining the fouling propensities of our membranes relative to each other. The high roughness polyamide surface of the DMF-TFC membrane was also rich in larger leaf-like structures, whereas the lower roughness NMP-TFC membrane polyamide layer contained more nodular and smaller features. The support layers of the two membrane types were also characterized for their morphological properties, and the relation between support layer surface structure and polyamide active layer formation was discussed. Taken together, our findings indicate that support layer structure has a significant impact on the fouling propensity of the active layer, and this impact should be considered in the design of support layer structures for TFC membranes. PMID:25564877

  9. Multifunctional thin film surface

    DOEpatents

    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.

  10. Plasma Spray Physical Vapor Deposition of La1- x Sr x Co y Fe1- y O3-δ Thin-Film Oxygen Transport Membrane on Porous Metallic Supports

    NASA Astrophysics Data System (ADS)

    Jarligo, Maria Ophelia; Mauer, Georg; Bram, Martin; Baumann, Stefan; Vaßen, Robert

    2014-01-01

    Plasma spray physical vapor deposition (PS-PVD) is a very promising route to manufacture ceramic coatings, combining the efficiency of thermal spray processes and characteristic features of thin PVD coatings. Recently, this technique has been investigated to effectively deposit dense thin films of perovskites particularly with the composition of La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) for application in gas separation membranes. Furthermore, asymmetric type of membranes with porous metallic supports has also attracted research attention due to the advantage of good mechanical properties suitable for use at high temperatures and high permeation rates. In this work, both approaches are combined to manufacture oxygen transport membranes made of gastight LSCF thin film by PS-PVD on porous NiCoCrAlY metallic supports. The deposition of homogenous dense thin film is challenged by the tendency of LSCF to decompose during thermal spray processes, irregular surface profile of the porous metallic substrate and crack and pore-formation in typical ceramic thermal spray coatings. Microstructure formation and coating build-up during PS-PVD as well as the annealing behavior at different temperatures of LSCF thin films were investigated. Finally, measurements of leak rates and oxygen permeation rates at elevated temperatures show promising results for the optimized membranes.

  11. High-Performance Protonic Ceramic Fuel Cells with Thin-Film Yttrium-Doped Barium Cerate-Zirconate Electrolytes on Compositionally Gradient Anodes.

    PubMed

    Bae, Kiho; Lee, Sewook; Jang, Dong Young; Kim, Hyun Joong; Lee, Hunhyeong; Shin, Dongwook; Son, Ji-Won; Shim, Joon Hyung

    2016-04-13

    In this study, we used a compositionally gradient anode functional layer (AFL) consisting of Ni-BaCe(0.5)Zr(0.35)Y(0.15)O(3-δ) (BCZY) with increasing BCZY contents toward the electrolyte-anode interface for high-performance protonic ceramic fuel cells. It is identified that conventional homogeneous AFLs fail to stably accommodate a thin film of BCZY electrolyte. In contrast, a dense 2 μm thick BCZY electrolyte was successfully deposited onto the proposed gradient AFL with improved adhesion. A fuel cell containing this thin electrolyte showed a promising maximum peak power density of 635 mW cm(-2) at 600 °C, with an open-circuit voltage of over 1 V. Impedance analysis confirmed that minimizing the electrolyte thickness is essential for achieving a high power output, suggesting that the anode structure is important in stably accommodating thin electrolytes.

  12. Impact of nanostructured anode on low-temperature performance of thin-film-based anode-supported solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Park, Jung Hoon; Han, Seung Min; Yoon, Kyung Joong; Kim, Hyoungchul; Hong, Jongsup; Kim, Byung-Kook; Lee, Jong-Ho; Son, Ji-Won

    2016-05-01

    The impact of a nanostructured Ni-yttria-stabilized zirconia (Ni-YSZ) anode on low-temperature solid oxide fuel cell (LT-SOFC) performance is investigated. By modifying processing techniques for the anode support, anode-supported SOFCs based on thin-film (∼1 μm) electrolytes (TF-SOFCs) with and without the nanostructured Ni-YSZ (grain size ∼100 nm) anode are fabricated and a direct comparison of the TF-SOFCs to reveal the role of the nanostructured anode at low temperature is made. The cell performance of the nanostructured Ni-YSZ anode significantly increases as compared to that of the cell without it, especially at low temperatures (500 °C). The electrochemical analyses confirm that increasing the triple-phase boundary (TPB) density near the electrolyte and anode interface by the particle-size reduction of the anode increases the number of sites available for charge transfer. Thus, the nanostructured anode not only secures the structural integrity of the thin-film components over it, it is also essential for lowering the operating temperature of the TF-SOFC. Although it is widely considered that the cathode is the main factor that determines the performance of LT-SOFCs, this study directly proves that anode performance also significantly affects the low-temperature performance.

  13. Acetone-activated polyimide electrospun nanofiber membrane for thin-film microextraction and thermal desorption-gas chromatography-mass spectrometric analysis of phenols in environmental water.

    PubMed

    Li, Shenghong; Wu, Dapeng; Yan, Xiaohui; Guan, Yafeng

    2015-09-11

    In this work, a polyimide nanofiber membrane was electrospun and applied as sorbent for thin film microextraction (TFME). After TFME of phenols in water samples, direct thermal desorption of the sorbent at 300°C followed by gas chromatography-mass spectrometric (TD-GC-MS) analysis was carried out. The extraction efficiency of TFME was enhanced by 6-12 times for phenols after activation with acetone. The positive effect of acetone activation was correlated to the increased hydrophilicity of the membrane. Extraction parameters, including mass of nanofiber membrane, pH value, NaCl concentration and extraction time, were optimized. Under optimal conditions, the LODs and LOQs for analysis of phenols in spiked purified water were 0.0006-0.008 and 0.002-0.025μgL(-1), respectively. The linearity range was more than two orders of magnitude (R>0.99). The RSDs of intra-batch and inter-batch were 4.3-7.4% and 2.7-10.6% (n=3). Finally the method was applied to real samples, including tap water, sea water, and waste water. These results indicate that the polyimide nanofiber membrane is a promising candidate as TFME sorbent for determination of polar analytes in water samples coupled with TD-GC-MS.

  14. Sustainable Process for the Preparation of High-Performance Thin-Film Composite Membranes using Ionic Liquids as the Reaction Medium.

    PubMed

    Mariën, Hanne; Bellings, Lotte; Hermans, Sanne; Vankelecom, Ivo F J

    2016-05-23

    A new form of interfacial polymerization to synthesize thin-film composite membranes realizes a more sustainable membrane preparation and improved nanofiltration performance. By introducing an ionic liquid (IL) as the organic reaction phase, the extremely different physicochemical properties to those of commonly used organic solvents influenced the top-layer formation in several beneficial ways. In addition to the elimination of hazardous solvents in the preparation, the m-phenylenediamine (MPD) concentration could be reduced 20-fold, and the use of surfactants and catalysts became redundant. Together with the more complete recycling of the organic phase in the water/IL system, these factors resulted in a 50 % decrease in the mass intensity of the top-layer formation. Moreover, a much thinner top layer with a high ethanol permeance of 0.61 L m(-2)  h(-1)  bar(-1) [99 % Rose Bengal (RB, 1017 Da) retention; 1 bar=0.1 MPa] was formed without the use of any additives. This EtOH permeance is 555 and 161 % higher than that for the conventional interfacial polymerization (without and with additives, respectively). In reverse osmosis, high NaCl retentions of 97 % could be obtained. Finally, the remarkable decrease in the membrane surface roughness indicates the potential for reduced fouling with this new type of membrane. PMID:27116588

  15. O2-binding albumin thin films: solid membranes of poly(ethylene glycol)-conjugated human serum albumin incorporating iron porphyrin.

    PubMed

    Nakagawa, Akito; Komatsu, Teruyuki; Huang, Yubin; Lu, Gang; Tsuchida, Eishun

    2007-01-01

    Poly(ethylene glycol) (PEG)-conjugated human serum albumin (HSA) incorporating the tetrakis(alpha,alpha,alpha,alpha-o-amidophenyl)porphinatoiron(II) derivative (FeP) [PEG(HSA-FeP)] is a unique plasma protein-based O2 carrier as a red blood cell substitute. The aqueous solution of PEG(HSA-FeP) [mw of PEG: 2-kDa (PEG2) or 5-kDa (PEG5)] was evaporated on a glass surface to produce a red-colored solid membrane. Scanning electron microscopy observations revealed that the PEG2(HSA-FeP) membrane consisted of two parts: (i) a surface layer made of a fibrous component (10 microm thickness), and (ii) a bottom layer of an amorphous phase (5 microm thickness). The condensed solution provided a thick membrane (70 microm), which also has the amorphous bottom layer. On the other hand, the PEG5(HSA-FeP) produced homogeneous membrane made of the fibrous component. The FeP active sites in the solid membrane formed very stable O2-adduct complexes at 37 degrees C with a half-lifetime of 40 h. The O2-binding affinity of the PEG2(HSA-FeP) membrane (P1/2 = 40 Torr, 25 degrees C) was 4-fold lower than that in aqueous solution, which is kinetically due to the low association rate constant. The membrane was soluble again in water and organic solvents (ethanol and chloroform) without deformation of the secondary structure of the protein. The addition of hyaluronic acid gave a free-standing flexible thin film, and it can also bind and release O2 as well. These O2-carrying albumin membranes with a micrometer-thickness would be of significant medical importance for a variety of clinical treatments.

  16. Piezoelectric thin films and their applications for electronics

    NASA Astrophysics Data System (ADS)

    Yoshino, Yukio

    2009-03-01

    ZnO and AlN piezoelectric thin films have been studied for applications in bulk acoustic wave (BAW) resonator. This article introduces methods of forming ZnO and AlN piezoelectric thin films by radio frequency sputtering and applications of BAW resonators considering the relationship between the crystallinity of piezoelectric thin films and the characteristics of the BAW resonators. Using ZnO thin films, BAW resonators were fabricated for a contour mode at 3.58 MHz and thickness modes from 200 MHz to 5 GHz. The ZnO thin films were combined with various materials, substrates, and thin films to minimize the temperature coefficient of frequency (TCF). The minimum TCF of BAW resonators was approximately 2 ppm/°C in the range -20 to 80 °C. The electromechanical coupling coefficient (k2) in a 1.9 GHz BAW resonator was 6.9%. Using AlN thin films, 5-20 GHz BAW resonators with an ultrathin membrane were realized. The membrane thickness of a 20 GHz BAW resonator was about 200 nm, k2 was 6.1%, and the quality factor (Q) was about 280. Q decreased with increasing resonant frequency. The value of k2 is almost the same for 5-20 GHz resonators. This result could be obtained by improving the thickness uniformity, by controlling internal stress of thin films, and by controlling the crystallinity of AlN piezoelectric thin film.

  17. Thin-film microelectric arrays for amperometric enzyme biosensors with electrochemically synthesized glucose oxidase-polyaniline membrane

    NASA Astrophysics Data System (ADS)

    Dzyadevich, Sergei V.; Rossokhaty, Victor K.; Shram, Nataly; Shul'ga, Alexander A.; Soldatkin, Alexey P.; Strikha, Vitaly I.

    1994-10-01

    An amperometric glucose biosensor was fabricated by the electrochemical polymerization of aniline onto a gold electrodes in presence of glucose oxidase in phosphate buffer solution, pH 7.0. Aniline is easily polymerized forming a thin film, which adheres tightly on the electrodes surface. During the electropolymerization process the enzyme was entrapped into the polyaniline film being able to catalyze the hydrolysis of glucose. The experiments were performed to determine the optimal condition for polyaniline-glucose oxidase film preparation. Glucose can be determined by the biosensor in the concentration range 10-4 M to 2 X 10-2 M. The linearity of the biosensor response was observed from 2 X 10-4 M to 6 X 10-3 M glucose, which demonstrated that the internal diffusion of substrates and products of reaction through the polyaniline layer to the electrodes surface was the main limiting factor controlling the response value. The method of electropolymerization was found to have several advantage in comparison with other approaches especially for further mass manufacturing of the biosensors.

  18. Thin film temperature sensor

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.

    1980-01-01

    Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

  19. Thin film ceramic thermocouples

    NASA Technical Reports Server (NTRS)

    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.

  20. Thin films for material engineering

    NASA Astrophysics Data System (ADS)

    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.

  1. Thin film solar cell workshop

    NASA Technical Reports Server (NTRS)

    Armstrong, Joe; Jeffrey, Frank

    1993-01-01

    A summation of responses to questions posed to the thin-film solar cell workshop and the ensuing discussion is provided. Participants in the workshop included photovoltaic manufacturers (both thin film and crystalline), cell performance investigators, and consumers.

  2. NMR characterization of thin films

    DOEpatents

    Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2010-06-15

    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.

  3. NMR characterization of thin films

    DOEpatents

    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.

  4. Thin film photovoltaic cell

    DOEpatents

    Meakin, John D.; Bragagnolo, Julio

    1982-01-01

    A thin film photovoltaic cell having a transparent electrical contact and an opaque electrical contact with a pair of semiconductors therebetween includes utilizing one of the electrical contacts as a substrate and wherein the inner surface thereof is modified by microroughening while being macro-planar.

  5. Fuel cell membrane humidification

    DOEpatents

    Wilson, Mahlon S.

    1999-01-01

    A polymer electrolyte membrane fuel cell assembly has an anode side and a cathode side separated by the membrane and generating electrical current by electrochemical reactions between a fuel gas and an oxidant. The anode side comprises a hydrophobic gas diffusion backing contacting one side of the membrane and having hydrophilic areas therein for providing liquid water directly to the one side of the membrane through the hydrophilic areas of the gas diffusion backing. In a preferred embodiment, the hydrophilic areas of the gas diffusion backing are formed by sewing a hydrophilic thread through the backing. Liquid water is distributed over the gas diffusion backing in distribution channels that are separate from the fuel distribution channels.

  6. Simulated Thin-Film Growth and Imaging

    NASA Astrophysics Data System (ADS)

    Schillaci, Michael

    2001-06-01

    Thin-films have become the cornerstone of the electronics, telecommunications, and broadband markets. A list of potential products includes: computer boards and chips, satellites, cell phones, fuel cells, superconductors, flat panel displays, optical waveguides, building and automotive windows, food and beverage plastic containers, metal foils, pipe plating, vision ware, manufacturing equipment and turbine engines. For all of these reasons a basic understanding of the physical processes involved in both growing and imaging thin-films can provide a wonderful research project for advanced undergraduate and first-year graduate students. After producing rudimentary two- and three-dimensional thin-film models incorporating ballsitic deposition and nearest neighbor Coulomb-type interactions, the QM tunneling equations are used to produce simulated scanning tunneling microscope (SSTM) images of the films. A discussion of computational platforms, languages, and software packages that may be used to accomplish similar results is also given.

  7. Microbial fuel cells and osmotic membrane bioreactors have mutual benefits for wastewater treatment and energy production.

    PubMed

    Hou, Dianxun; Lu, Lu; Ren, Zhiyong Jason

    2016-07-01

    This study demonstrates that microbial fuel cells (MFCs) and osmotic membrane bioreactors (OMBRs) can be mutually beneficial when integrated together for wastewater treatment. When connecting MFCs with OMBRs, the solute buildup increased conductivity and buffer capacity, which greatly increased MFC power density from 3 W/m(3) up to 11.5 W/m(3). In turn, the MFCs conditioned and reduced sludge production and therefore reduced forward osmosis (FO) membrane fouling. The MFC-OMBR equipped with new thin-film composite (TFC) membrane showed excellent organic (>95%) and phosphorus removal (>99%) and therefore maintained effluent sCOD below 20 mg/L. However, the nitrogen removal was limited due to the negative surface charge of the thin-film composite membrane and solution chemistry, which led to higher flux of ammonium toward the OMBR draw solution. Further studies are needed to improve nitrogen removal, reduce fouling, and optimize system integration. PMID:27105032

  8. Thin-film optical initiator

    DOEpatents

    Erickson, Kenneth L.

    2001-01-01

    A thin-film optical initiator having an inert, transparent substrate, a reactive thin film, which can be either an explosive or a pyrotechnic, and a reflective thin film. The resultant thin-film optical initiator system also comprises a fiber-optic cable connected to a low-energy laser source, an output charge, and an initiator housing. The reactive thin film, which may contain very thin embedded layers or be a co-deposit of a light-absorbing material such as carbon, absorbs the incident laser light, is volumetrically heated, and explodes against the output charge, imparting about 5 to 20 times more energy than in the incident laser pulse.

  9. [Spectral emissivity of thin films].

    PubMed

    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.

  10. A novel positively charged membrane based on polyamide thin-film composite made by cross-linking for nanofiltration.

    PubMed

    Akbari, Ahmad; Fakharshakeri, Zahra; Mojallali Rostami, Sayed Majid

    2016-01-01

    In this paper, a novel positively charged membrane was prepared through interfacial polymerization technique between polyethyleneimine in aqueous phase and trimesoyl chloride in organic phase. Next, cross-linking of polyamide (PA) layer using ρ-xylylene dichloride (XDC) and glutaraldehyde (GA) was studied. The influences of cross-linking concentrations on the separation and permeation performance of membrane were also investigated. Membranes were characterized in terms of their chemical structure, the cross-sectional and surface morphologies, contact angles, molecular weight cut-off (MWCO) and effect of pH feed solution. The salt rejection sequence of CaCl2 >NaCl > Na2SO4 showed a positive charge at the membrane surface after cross-linking reaction. The MWCO of primary PA membrane decreased from 1,135 to 775 and 885 Da for XDC and GA, respectively. XDC membrane shows highest CaCl2 divalent cationic rejection (95.5%) and lowest water flux (21.1 L/m(2).h). This study illustrates a promising method for fabrication of positively charged membrane in cation separation. PMID:26901720

  11. Thin film superconductor magnetic bearings

    DOEpatents

    Weinberger, Bernard R.

    1995-12-26

    A superconductor magnetic bearing includes a shaft (10) that is subject to a load (L) and rotatable around an axis of rotation, a magnet (12) mounted to the shaft, and a stator (14) in proximity to the shaft. The stator (14) has a superconductor thin film assembly (16) positioned to interact with the magnet (12) to produce a levitation force on the shaft (10) that supports the load (L). The thin film assembly (16) includes at least two superconductor thin films (18) and at least one substrate (20). Each thin film (18) is positioned on a substrate (20) and all the thin films are positioned such that an applied magnetic field from the magnet (12) passes through all the thin films. A similar bearing in which the thin film assembly (16) is mounted on the shaft (10) and the magnet (12) is part of the stator (14) also can be constructed.

  12. In situ redox speciation analysis of chromium in water by diffusive gradients in thin films using a DE81 anion exchange membrane.

    PubMed

    Suárez, Carlos A; de Simone, Thays V; Menegário, Amauri A; Rolisola, Ana M C M; Luko, Karen S; Gastmans, Didier; da Conceição, Fabiano T; Kiang, Chang H

    2016-07-01

    A method for the in situ redox speciation analysis of chromium in water by the diffusive gradients in thin films (DGT) technique using a DE81 anion exchange membrane was successfully developed. For the selective uptake of Cr(VI), a DGT device containing an anion exchange membrane DE81 (cellulose acetate chromatographic paper) was used (DE81-DGT), while selective uptake of Cr(III) was carried out using DGT devices containing the Chelex-100 resin (Chelex-100-DGT). A correlation coefficient of 0.993 was obtained for the linearity of the immersion curves (mass versus time) using DE81-DGT. The diffusion coefficient values for Cr(VI) through the agarose diffusive layer were equal to 4.89±0.5×10(-6)cm(2)s(-1) and 3.95±0.02×10(-6)cm(2)s(-1) (T=23±1°C, I=0.03molL(-1) NaNO3) were obtained by using diffusion cell and immersion curves, respectively. The retention of Cr(VI) by the DE81 membrane in a synthetic sample and river water was not affected by the pH over a wide range 4-9). Recoveries of Cr(VI) between 90% and 120% from solutions of ionic strength ranging from 0.01 to 0. 5molL(-1) NaNO3 were achieved. Finally, the redox speciation analysis of Cr(III) and Cr(VI) in spiked river water and synthetic samples was performed with recoveries greater than 80% and 87% by using Chelex-100-DGT and DE81-DGT devices, respectively. Those results were in excellent agreement with the diphenylcarbazide spectrophotometric method. PMID:27154678

  13. Biomimetic thin film deposition

    SciTech Connect

    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.

  14. Advanced thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Kreider, K. G.; Semancik, S.; Olson, C.

    1984-01-01

    The fabrication, materials characterization, and performance of thin film platinum rhodium thermocouples on gas turbine alloys was investigated. The materials chosen for the study were the turbine blade alloy systems MAR M200+Hf with NiCoCrAlY and FeCrAlY coatings, and vane alloy systems MAR M509 with FeCrAlY. Research was focussed on making improvements in the problem areas of coating substrate stability, adhesion, and insulation reliability and durability. Diffusion profiles between the substrate and coating with and without barrier coatings of Al2O3 are reported. The relationships between fabrication parameters of thermal oxidation and sputtering of the insulator and its characterization and performance are described. The best thin film thermocouples were fabricated with the NiCoCrAlY coatings which were thermally oxidized and sputter coated with Al2O3.

  15. Development of a Carbon Mesh Supported Thin Film Microextraction Membrane As a Means to Lower the Detection Limits of Benchtop and Portable GC/MS Instrumentation.

    PubMed

    Grandy, Jonathan J; Boyacı, Ezel; Pawliszyn, Janusz

    2016-02-01

    In this work, a durable and easy to handle thin film microextraction (TFME) device is reported. The membrane is comprised of poly(divinylbenzene) (DVB) resin particles suspended in a high-density polydimethylsiloxane (PDMS) glue, which is spread onto a carbon fiber mesh. The currently presented membrane was shown to exhibit a substantially lesser amount of siloxane bleed during thermal desorption, while providing a statistically similar extraction efficiency toward a broad spectrum of analytes varying in polarity when compared to an unsupported DVB/PDMS membrane of similar shape and size which was prepared with previously published methods. With the use of hand-portable GC-TMS instrumentation, membranes cut with dimensions 40 mm long by 4.85 mm wide and 40 ± 5 μm thick (per side) were shown to extract 21.2, 19.8, 18.5, 18,4, 26.8, and 23.7 times the amount of 2,4 dichlorophenol, 2,4,6 trichlorophenol, phorate D10, fonofos, chloropyrifos, and parathion, respectively, within 15 min from a 10 ppb aqueous solution as compared to a 65 μm DVB/PDMS solid phase microextraction (SPME) fiber. A portable high volume desorption module prototype was also evaluated and shown to be appropriate for the desorption of analytes with a volatility equal to or lesser than benzene when employed in conjunction with TFME membranes. Indeed, the coupling of these TFME devices to hand-portable gas chromatography toroidial ion trap mass spectrometry (GC-TMS) instrumentation was shown to push detection limits for these pesticides down to the hundreds of ppt levels, nearing that which can be achieved with benchtop instrumentation. Where these membranes can also be coupled to benchtop instrumentation it is reasonable to assume that detection limits could be pushed down even further. As a final proof of the concept, the first ever, entirely on-site TFME-GC-TMS analysis was performed at a construction impacted lake. Results had indicated the presence of contaminants such as toluene, ethylbenzene

  16. Tailored adhesion behavior of polyelectrolyte thin films deposited on plasma-treated poly(dimethylsiloxane) for functionalized membranes

    NASA Astrophysics Data System (ADS)

    Bassil, Joelle; Alem, Halima; Henrion, Gérard; Roizard, Denis

    2016-04-01

    Completely homogenous films formed via the layer-by-layer assembly of poly(diallyldimethylammonium chloride) (PDADMAC) and the poly(styrene sulfonate) were successfully obtained on plasma-treated poly(dimethylsiloxane) (PDMS) substrates. To modify the hydrophobicity of the PDMS surface, a cold plasma treatment was previously applied to the membrane, which led to the creation of hydrophilic groups on the surface of the membrane. PDMS wettability and surface morphology were successfully correlated with the plasma parameters. A combination of contact angle measurements, scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis was used to demonstrate that homogeneous and hydrophilic surfaces could be achieved on PDMS cold-plasma-treated membranes. The stability of the assembled PEL layer on the PDMS was evaluated using a combination of pull-off testing and X-ray photoelectron spectroscopy (XPS), which confirmed the relevance of a plasma pre-treatment as the adhesion of the polyelectrolyte multilayers was greatly enhanced when the deposition was completed on an activated PDMS surface at 80 W for 5 min.

  17. Carbon thin film thermometry

    NASA Technical Reports Server (NTRS)

    Collier, R. S.; Sparks, L. L.; Strobridge, T. R.

    1973-01-01

    The work concerning carbon thin film thermometry is reported. Optimum film deposition parameters were sought on an empirical basis for maximum stability of the films. One hundred films were fabricated for use at the Marshall Space Flight Center; 10 of these films were given a precise quasi-continuous calibration of temperature vs. resistance with 22 intervals between 5 and 80 K using primary platinum and germanium thermometers. Sensitivity curves were established and the remaining 90 films were given a three point calibration and fitted to the established sensitivity curves. Hydrogen gas-liquid discrimination set points are given for each film.

  18. Thin film hydrogen sensor

    DOEpatents

    Lauf, Robert J.; Hoffheins, Barbara S.; Fleming, Pamela H.

    1994-01-01

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed.

  19. Thin film photovoltaic device

    DOEpatents

    Catalano, Anthony W.; Bhushan, Manjul

    1982-01-01

    A thin film photovoltaic solar cell which utilizes a zinc phosphide semiconductor is of the homojunction type comprising an n-type conductivity region forming an electrical junction with a p-type region, both regions consisting essentially of the same semiconductor material. The n-type region is formed by treating zinc phosphide with an extrinsic dopant such as magnesium. The semiconductor is formed on a multilayer substrate which acts as an opaque contact. Various transparent contacts may be used, including a thin metal film of the same chemical composition as the n-type dopant or conductive oxides or metal grids.

  20. Thin film magnetism

    SciTech Connect

    Bader, S.D. )

    1990-06-01

    New developments in thin-film magnetism are reviewed with an emphasis on the ultrathin regime. The scope includes relatively simple metallic systems in overlayer, sandwich, and superlattice configurations. Sample fabrication, characterization, and magnetic measurement techniques are outlined by highlighting some of the more modern experimental innovations. Current issues and advances that demonstrate the symbiotic relationship between experiment and theory are then examined, including the surface magnetic anisotropy, the two-dimensional critical behavior, the creation of metastable phases via epitaxy, and phenomena associated with coupled magnetic layers. The review ends with a brief account of the impact of the various contemporary developments on the applications area.

  1. Nonlinear optical microscopy for imaging thin films and surfaces

    SciTech Connect

    Smilowitz, L.B.; McBranch, D.W.; Robinson, J.M.

    1995-03-01

    We have used the inherent surface sensitivity of second harmonic generation to develop an instrument for nonlinear optical microscopy of surfaces and interfaces. We have demonstrated the use of several nonlinear optical responses for imaging thin films. The second harmonic response of a thin film of C{sub 60} has been used to image patterned films. Two photon absorption light induced fluorescence has been used to image patterned thin films of Rhodamine 6G. Applications of nonlinear optical microscopy include the imaging of charge injection and photoinduced charge transfer between layers in semiconductor heterojunction devices as well as across membranes in biological systems.

  2. Thin film mechanics

    NASA Astrophysics Data System (ADS)

    Cooper, Ryan C.

    This doctoral thesis details the methods of determining mechanical properties of two classes of novel thin films suspended two-dimensional crystals and electron beam irradiated microfilms of polydimethylsiloxane (PDMS). Thin films are used in a variety of surface coatings to alter the opto-electronic properties or increase the wear or corrosion resistance and are ideal for micro- and nanoelectromechanical system fabrication. One of the challenges in fabricating thin films is the introduction of strains which can arise due to application techniques, geometrical conformation, or other spurious conditions. Chapters 2-4 focus on two dimensional materials. This is the intrinsic limit of thin films-being constrained to one atomic or molecular unit of thickness. These materials have mechanical, electrical, and optical properties ideal for micro- and nanoelectromechanical systems with truly novel device functionality. As such, the breadth of applications that can benefit from a treatise on two dimensional film mechanics is reason enough for exploration. This study explores the anomylously high strength of two dimensional materials. Furthermore, this work also aims to bridge four main gaps in the understanding of material science: bridging the gap between ab initio calculations and finite element analysis, bridging the gap between ab initio calculations and experimental results, nanoscale to microscale, and microscale to mesoscale. A nonlinear elasticity model is used to determine the necessary elastic constants to define the strain-energy density function for finite strain. Then, ab initio calculations-density functional theory-is used to calculate the nonlinear elastic response. Chapter 2 focuses on validating this methodology with atomic force microscope nanoindentation on molybdenum disulfide. Chapter 3 explores the convergence criteria of three density functional theory solvers to further verify the numerical calculations. Chapter 4 then uses this model to investigate

  3. Thin films: Past, present, future

    SciTech Connect

    Zweibel, K

    1995-04-01

    This report describes the characteristics of the thin film photovoltaic modules necessary for an acceptable rate of return for rural areas and underdeveloped countries. The topics of the paper include a development of goals of cost and performance for an acceptable PV system, a review of current technologies for meeting these goals, issues and opportunities in thin film technologies.

  4. Thin film ion conducting coating

    DOEpatents

    Goldner, Ronald B.; Haas, Terry; Wong, Kwok-Keung; Seward, George

    1989-01-01

    Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

  5. Polyimide Aerogel Thin Films

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann; Guo, Haiquan

    2012-01-01

    Polyimide aerogels have been crosslinked through multifunctional amines. This invention builds on "Polyimide Aerogels With Three-Dimensional Cross-Linked Structure," and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form. Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cubic cm. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 sq m/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the cross-linked polyimide aerogels have higher modulus than polymer-reinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.

  6. Thin film interconnect processes

    NASA Astrophysics Data System (ADS)

    Malik, Farid

    Interconnects and associated photolithography and etching processes play a dominant role in the feature shrinkage of electronic devices. Most interconnects are fabricated by use of thin film processing techniques. Planarization of dielectrics and novel metal deposition methods are the focus of current investigations. Spin-on glass, polyimides, etch-back, bias-sputtered quartz, and plasma-enhanced conformal films are being used to obtain planarized dielectrics over which metal films can be reliably deposited. Recent trends have been towards chemical vapor depositions of metals and refractory metal silicides. Interconnects of the future will be used in conjunction with planarized dielectric layers. Reliability of devices will depend to a large extent on the quality of the interconnects.

  7. Ferromagnetic thin films

    DOEpatents

    Krishnan, Kannan M.

    1994-01-01

    A ferromagnetic .delta.-Mn.sub.1-x Ga.sub.x thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of .delta.-Mn.sub.1-x Ga.sub.x overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of .delta.-Mn.sub.1-x Ga.sub.x and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4 .+-.0.05.

  8. Ferromagnetic thin films

    DOEpatents

    Krishnan, K.M.

    1994-12-20

    A ferromagnetic [delta]-Mn[sub 1[minus]x]Ga[sub x] thin film having perpendicular anisotropy is described which comprises: (a) a GaAs substrate, (b) a layer of undoped GaAs overlying said substrate and bonded thereto having a thickness ranging from about 50 to about 100 nanometers, (c) a layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] overlying said layer of undoped GaAs and bonded thereto having a thickness ranging from about 20 to about 30 nanometers, and (d) a layer of GaAs overlying said layer of [delta]-Mn[sub 1[minus]x]Ga[sub x] and bonded thereto having a thickness ranging from about 2 to about 5 nanometers, wherein x is 0.4[+-]0.05. 7 figures.

  9. Thin film hydrogen sensor

    DOEpatents

    Lauf, R.J.; Hoffheins, B.S.; Fleming, P.H.

    1994-11-22

    A hydrogen sensor element comprises an essentially inert, electrically-insulating substrate having a thin-film metallization deposited thereon which forms at least two resistors on the substrate. The metallization comprises a layer of Pd or a Pd alloy for sensing hydrogen and an underlying intermediate metal layer for providing enhanced adhesion of the metallization to the substrate. An essentially inert, electrically insulating, hydrogen impermeable passivation layer covers at least one of the resistors, and at least one of the resistors is left uncovered. The difference in electrical resistances of the covered resistor and the uncovered resistor is related to hydrogen concentration in a gas to which the sensor element is exposed. 6 figs.

  10. Membrane and MEA Development in Polymer Electrolyte Fuel Cells

    NASA Astrophysics Data System (ADS)

    Trogadas, Panagiotis; Ramani, Vijay

    The polymer electrolyte fuel cell (PEFC) is based on Nafion polymer membranes operating at a temperature of 80°C. The main characteristics (structure and properties) and problems of Nafion-based PEFC technology are discussed. The primary drawbacks of Nafion membranes are poor conductivity at low relative humidities (and consequently at temperatures >100°C and ambient pressure) and large crossover of methanol in direct methanol fuel cell (DMFC) applications. These drawbacks have prompted an extensive effort to improve the properties of Nafion and identify alternate materials to replace Nafion. Polymer electrolyte membranes (PEMs) are classified in modified Nafion, membranes based on functionalized non-fluorinated backbones and acid-base polymer systems. Perhaps the most widely employed approach is the addition of inorganic additives to Nafion membranes to yield organic/inorganic composite membranes. Four major types of inorganic additives that have been studied (zirconium phosphates, heteropolyacids, metal hydrogen sulfates, and metal oxides) are reviewed in the following. DMFC and H2/O2 (air) cells based on modified Nafion membranes have been successfully operated at temperatures up to 120°C under ambient pressure and up to 150°C under 3-5 atm. Membranes based on functionalized non-fluorinated backbones are potentially promising for high-temperature operation. High conductivities have been obtained at temperatures up to 180°C. The final category of polymeric PEMs comprises non-functionalized polymers with basic character doped with proton-conducting acids such as phosphoric acid. The advanced features include high CO tolerance and thermal management. The advances made in the fabrication of electrodes for PEM fuel cells from the PTFE-bound catalyst layers of almost 20 years ago to the present technology are briefly discussed. There are two widely employed electrode designs: (1) PTFE-bound, and (2) thin-film electrodes. Emerging methods include those featuring

  11. Nonlinear optical thin films

    NASA Technical Reports Server (NTRS)

    Leslie, Thomas M.

    1993-01-01

    A focused approach to development and evaluation of organic polymer films for use in optoelectronics is presented. The issues and challenges that are addressed include: (1) material synthesis, purification, and the tailoring of the material properties; (2) deposition of uniform thin films by a variety of methods; (3) characterization of material physical properties (thermal, electrical, optical, and electro-optical); and (4) device fabrication and testing. Photonic materials, devices, and systems were identified as critical technology areas by the Department of Commerce and the Department of Defense. This approach offers strong integration of basic material issues through engineering applications by the development of materials that can be exploited as the active unit in a variety of polymeric thin film devices. Improved materials were developed with unprecedented purity and stability. The absorptive properties can be tailored and controlled to provide significant improvement in propagation losses and nonlinear performance. Furthermore, the materials were incorporated into polymers that are highly compatible with fabrication and patterning processes for integrated optical devices and circuits. By simultaneously addressing the issues of materials development and characterization, keeping device design and fabrication in mind, many obstacles were overcome for implementation of these polymeric materials and devices into systems. We intend to considerably improve the upper use temperature, poling stability, and compatibility with silicon based devices. The principal device application that was targeted is a linear electro-optic modulation etalon. Organic polymers need to be properly designed and coupled with existing integrated circuit technology to create new photonic devices for optical communication, image processing, other laser applications such as harmonic generation, and eventually optical computing. The progression from microscopic sample to a suitable film

  12. Evaluation of performance and microbial ecology of sequencing batch reactor and membrane bioreactor treating thin-film transistor liquid crystal display wastewater.

    PubMed

    Wu, Y J; Whang, L M; Huang, S J; Yang, Y F; Lei, C N; Cheng, S S

    2008-01-01

    In Taiwan, a substantial amount of thin-film transistor liquid crystal display (TFT-LCD) wastewater is produced daily due to an increasing production of the opto-electronic industry in recent years. The main components of TFT-LCD wastewater include dimethyl sulphoxide (DMSO), monoethanolamine (MEA), and tetra-methyl ammonium hydroxide (TMAH), which are recognized as non-or slow-biodegradable organic compounds and limited information is available regarding their biological treatablility. This study was conducted to evaluate the long-term performance of two bioreactors, anaerobic-aerobic (A/O) sequencing batch reactor (SBR) and aerobic membrane bioreactor (MBR), treating synthetic TFT-LCD wastewater containing DMSO, MEA, and TMAH with different loadings. For the A/O SBR, the influent wastewater was composed of 800 mg MEA/L, 430 mg DMSO/L, and 90 mg TMAH/L, respectively. After reaching steady-state, SBR was able to achieve more than 99% degradation efficiencies for the three compounds examined. For the case of aerobic MBR, the influent wastewater was composed of 550 mg MEA/L, 270 mg DMSO/L, and 330 mg TMAH/L, respectively, and degradation efficiencies for the three compounds achieved more than 99%. Although both different reactors shared similar and satisfactory degradation efficiencies for DMSO, MEA, and TMAH, the microbial ecology of these two reactors, as elucidated with molecular methods, was apparently different. The 16S rDNA-based cloning/sequencing results indicated that the dominant sequences retrieved from the aerobic MBR, including Hyphomicrobium denitrificans, Hyphomicrobium zavarzinii, Rhodobacter sp., and Methyloversatilis universalis, showed a clear linkage to their physiological properties of DMSO and TMAH degradation. On the other hand, Zoogloea sp., Chlorobium chlorochromatii, Agricultural soil bacterium, and Flavosolibacter ginsengiterrae were proliferated in the A/O SBR Run1, while Thiobacillus sp., Nitrosomonas sp., Thauera aromatica and Azoarcus

  13. Method for making surfactant-templated thin films

    DOEpatents

    Brinker, C. Jeffrey; Lu, Yunfeng; Fan, Hongyou

    2002-01-01

    An evaporation-induced self-assembly method to prepare a porous, surfactant-templated, thin film by mixing a silica sol, a solvent, a surfactant, and an interstitial compound, evaporating a portion of the solvent to form a liquid, crystalline thin film mesophase material, and then removal of the surfactant template. Coating onto a substrate produces a thin film with the interstitial compound either covalently bonded to the internal surfaces of the ordered or disordered mesostructure framework or physically entrapped within the ordered or disordered mesostructured framework. Particles can be formed by aerosol processing or spray drying rather than coating onto a substrate. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.

  14. Method for making surfactant-templated thin films

    DOEpatents

    Brinker, C. Jeffrey; Lu, Yunfeng; Fan, Hong You

    2010-08-31

    An evaporation-induced self-assembly method to prepare a porous, surfactant-templated, thin film by mixing a silica sol, a solvent, a surfactant, and an interstitial compound, evaporating a portion of the solvent to form a liquid, crystalline thin film mesophase material, and then removal of the surfactant template. Coating onto a substrate produces a thin film with the interstitial compound either covalently bonded to the internal surfaces of the ordered or disordered mesostructure framework or physically entrapped within the ordered or disordered mesostructured framework. Particles can be formed by aerosol processing or spray drying rather than coating onto a substrate. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.

  15. Host thin films incorporating nanoparticles

    NASA Astrophysics Data System (ADS)

    Qureshi, Uzma

    The focus of this research project was the investigation of the functional properties of thin films that incorporate a secondary nanoparticulate phase. In particular to assess if the secondary nanoparticulate material enhanced a functional property of the coating on glass. In order to achieve this, new thin film deposition methods were developed, namely use of nanopowder precursors, an aerosol assisted transport technique and an aerosol into atmospheric pressure chemical vapour deposition system. Aerosol assisted chemical vapour deposition (AACVD) was used to deposit 8 series of thin films on glass. Five different nanoparticles silver, gold, ceria, tungsten oxide and zinc oxide were tested and shown to successfully deposit thin films incorporating nanoparticles within a host matrix. Silver nanoparticles were synthesised and doped within a titania film by AACVD. This improved solar control properties. A unique aerosol assisted chemical vapour deposition (AACVD) into atmospheric pressure chemical vapour deposition (APCVD) system was used to deposit films of Au nanoparticles and thin films of gold nanoparticles incorporated within a host titania matrix. Incorporation of high refractive index contrast metal oxide particles within a host film altered the film colour. The key goal was to test the potential of nanopowder forms and transfer the suspended nanopowder via an aerosol to a substrate in order to deposit a thin film. Discrete tungsten oxide nanoparticles or ceria nanoparticles within a titanium dioxide thin film enhanced the self-cleaning and photo-induced super-hydrophilicity. The nanopowder precursor study was extended by deposition of zinc oxide thin films incorporating Au nanoparticles and also ZnO films deposited from a ZnO nanopowder precursor. Incorporation of Au nanoparticles within a VO: host matrix improved the thermochromic response, optical and colour properties. Composite VC/TiC and Au nanoparticle/V02/Ti02 thin films displayed three useful

  16. MOF thin films: existing and future applications.

    PubMed

    Shekhah, O; Liu, J; Fischer, R A; Wöll, Ch

    2011-02-01

    The applications and potentials of thin film coatings of metal-organic frameworks (MOFs) supported on various substrates are discussed in this critical review. Because the demand for fabricating such porous coatings is rather obvious, in the past years several synthesis schemes have been developed for the preparation of thin porous MOF films. Interestingly, although this is an emerging field seeing a rapid development a number of different applications on MOF films were either already demonstrated or have been proposed. This review focuses on the fabrication of continuous, thin porous films, either supported on solid substrates or as free-standing membranes. The availability of such two-dimensional types of porous coatings opened the door for a number of new perspectives for functionalizing surfaces. Also for the porous materials themselves, the availability of a solid support to which the MOF-films are rigidly (in a mechanical sense) anchored provides access to applications not available for the typical MOF powders with particle sizes of a few μm. We will also address some of the potential and applications of thin films in different fields like luminescence, QCM-based sensors, optoelectronics, gas separation and catalysis. A separate chapter has been devoted to the delamination of MOF thin films and discusses the potential to use them as free-standing membranes or as nano-containers. The review also demonstrates the possibility of using MOF thin films as model systems for detailed studies on MOF-related phenomena, e.g. adsorption and diffusion of small molecules into MOFs as well as the formation mechanism of MOFs (101 references).

  17. Thin-film Sensors for Space Propulsion Technology

    NASA Technical Reports Server (NTRS)

    Kim, W. S.; Englund, D. R.

    1985-01-01

    SSME components such as the turbine blades of the high pressure fuel turbopump are subjected to rapid and extreme thermal transients that contribute to blade cracking and subsequent failure. The objective was to develop thin film sensors for SSME components. The technology established for aircraft gas turbine engines was adopted to the materials and environment encountered in the SSME. Specific goals are to expand the existing thin film sensor technology, to continue developing improved sensor processing techniques, and to test the durability of aircraft gas turbine engine technology in the SSME environment. A thin film sensor laboratory is being installed in a refurbished clean room, and new sputtering and photoresist exposure equipment is being acquired. Existing thin film thermocouple technology in an SSME environment are being tested. Various coatings and their insulating films are being investigated for use in sensor development.

  18. Interference Colors in Thin Films.

    ERIC Educational Resources Information Center

    Armstrong, H. L.

    1979-01-01

    Explains interference colors in thin films as being due to the removal, or considerable reduction, of a certain color by destructive inteference that results in the complementary color being seen. (GA)

  19. Chiral atomically thin films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm–1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  20. Thin film composite actuators

    NASA Astrophysics Data System (ADS)

    Su, Quanmin; Kim, Taesung; Zheng, Yun; Wuttig, Manfred R.

    1995-05-01

    The mechanical properties of Ni50Ti50 deposited on Si substrates were studied focussing on the interaction of the film and substrate. This interaction determines the transformation characteristics through interface accommodation and mechanical constraints exerted by the substrate stiffness. Substrate stiffness, controlled by the film/substrate thickness ratio, was found to have a substantial influence on the output energy of the film/substrate composite. A switch type composite based on this knowledge was fabricated and tested. The thermo-mechanical properties of Terfenol-D thin films deposited on Si substrates were studied by static and dynamic measurements of film/substrate composite cantilevers. The Curie transition, (Delta) E effect and mechanical damping of the film were measured simultaneously. The stress in the film was controlled by annealing below the recrystallization temperature and determined to vary from -500 MPa, compression, in as deposited films to +480 MPa, tension, in annealed films. The Curie temperature shifts from 80 degree(s)C to 140 degree(s)C as the tension increases while the structure of the film remains amorphous. The stress change induced by annealing also drastically effects the film's damping characteristics. The (Delta) E effect of the amorphous material, about 20%, was used to estimate the magnetostriction, (lambda) s approximately equals 4 (DOT) 10-3.

  1. Chiral atomically thin films

    NASA Astrophysics Data System (ADS)

    Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong

    2016-06-01

    Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.

  2. Polycrystalline thin film photovoltaic technology

    SciTech Connect

    Ullal, H.S.; Zweibel, K.; Mitchell, R.L.; Noufi, R.

    1991-03-01

    Low-cost, high-efficiency thin-film modules are an exciting photovoltaic technology option for generating cost-effective electricity in 1995 and beyond. In this paper we review the significant technical progress made in the following thin films: copper indium diselenide, cadmium telluride, and polycrystalline thin silicon films. Also, the recent US DOE/SERI initiative to commercialize these emerging technologies is discussed. 6 refs., 9 figs.

  3. Nanostructured Thin Film Polymer Devices for Constant-Rate Protein Delivery

    PubMed Central

    Bernards, Daniel A.; Lance, Kevin D.; Ciaccio, Natalie A.; Desai, Tejal A.

    2012-01-01

    Herein long-term delivery of proteins from biodegradable thin film devices is demonstrated, where a nanostructured polymer membrane controls release. Protein was sealed between two poly(caprolactone) films, which generated the thin film devices. Protein release for 210 days was shown in vitro, and stable activity was established through 70 days with a model protein. These thin film devices present a promising delivery platform for biologic therapeutics, particularly for application in constrained spaces. PMID:22985294

  4. Thin film cell development workshop report

    NASA Technical Reports Server (NTRS)

    Woodyard, James R.

    1991-01-01

    The Thin Film Development Workshop provided an opportunity for those interested in space applications of thin film cells to debate several topics. The unique characteristics of thin film cells as well as a number of other issues were covered during the discussions. The potential of thin film cells, key research and development issues, manufacturing issues, radiation damage, substrates, and space qualification of thin film cells were discussed.

  5. Nanoscale Thin Film Electrolytes for Clean Energy Applications

    SciTech Connect

    Nandasiri, Manjula I.; Sanghavi, Rahul P.; Kuchibhatla, Satyanarayana V N T; Thevuthasan, Suntharampillai

    2012-02-01

    Ceria and zirconia based systems can be used as electrolytes to develop solid oxide fuel cells for clean energy production and to prevent air pollution by developing efficient, reliable oxygen sensors. In this study, we have used oxygen plasma assisted molecular beam epitaxy (OPA-MBE) to grow samaria doped ceria (SDC), to understand the role of dopant concentration and geometry of the films towards the ionic conduction in these thin films. We have also discussed the Gd doped CeO2 (GDC) and Gd stabilized ZrO2 (GSZ) multi-layer thin films to investigate the effect of interfacial phenomena on the ionic conductivity of these hetero-structures. We found the optimum concentration to be 15 mol % SmO1.5, for achieving lowest electrical resistance in SDC thin films. The electrical resistance decreases with the increase in film thickness up to 200 nm. The results demonstrate the usefulness of this study towards establishing an optimum dopant concentration and choosing an appropriate thin film thickness to ameliorate the conductance of the SDC material system. Furthermore, we have explored the conductivity of highly oriented GDC and GSZ multi-layer thin films, wherein the conductivity increased with an increase in the number of layers. The extended defects and lattice strain near the interfaces increase the density of oxygen vacancies, which leads to enhanced ionic conductivity in multi-layer thin films.

  6. Mesoporous silica as a membrane for ultra-thin implantable direct glucose fuel cells.

    PubMed

    Sharma, Tushar; Hu, Ye; Stoller, Meryl; Feldman, Marc; Ruoff, Rodney S; Ferrari, Mauro; Zhang, Xiaojing

    2011-07-21

    The design, fabrication and characterization of an inorganic catalyst based direct glucose fuel cell using mesoporous silica coating as a functional membrane is reported. The desired use of mesoporous silica based direct glucose fuel cell is for a blood vessel implantable device. Blood vessel implantable direct glucose fuel cells have access to higher continuous glucose concentrations. However, reduction in the implant thickness is required for application in the venous system as part of a stent. We report development of an implantable device with a platinum thin-film (thickness: 25 nm) deposited on silicon substrate (500 μm) to serve as the anode, and graphene pressed on a stainless steel mesh (175 μm) to serve as the cathode. Control experiments involved the use of a surfactant-coated polypropylene membrane (50 μm) with activated carbon (198 μm) electrodes. We demonstrate that a mesoporous silica thin film (270 nm) is capable of replacing the conventional polymer based membranes with an improvement in the power generated over conventional direct glucose fuel cells. PMID:21637881

  7. Fuel cell with ionization membrane

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T. (Inventor)

    2007-01-01

    A fuel cell is disclosed comprising an ionization membrane having at least one area through which gas is passed, and which ionizes the gas passing therethrough, and a cathode for receiving the ions generated by the ionization membrane. The ionization membrane may include one or more openings in the membrane with electrodes that are located closer than a mean free path of molecules within the gas to be ionized. Methods of manufacture are also provided.

  8. Selective inorganic thin films

    SciTech Connect

    Phillips, M.L.F.; Pohl, P.I.; Brinker, C.J.

    1997-04-01

    Separating light gases using membranes is a technology area for which there exists opportunities for significant energy savings. Examples of industrial needs for gas separation include hydrogen recovery, natural gas purification, and dehydration. A membrane capable of separating H{sub 2} from other gases at high temperatures could recover hydrogen from refinery waste streams, and facilitate catalytic dehydrogenation and the water gas shift (CO + H{sub 2}O {yields} H{sub 2} + CO{sub 2}) reaction. Natural gas purification requires separating CH{sub 4} from mixtures with CO{sub 2}, H{sub 2}S, H{sub 2}O, and higher alkanes. A dehydrating membrane would remove water vapor from gas streams in which water is a byproduct or a contaminant, such as refrigeration systems. Molecular sieve films offer the possibility of performing separations involving hydrogen, natural gas constituents, and water vapor at elevated temperatures with very high separation factors. It is in applications such as these that the authors expect inorganic molecular sieve membranes to compete most effectively with current gas separation technologies. Cryogenic separations are very energy intensive. Polymer membranes do not have the thermal stability appropriate for high temperature hydrogen recovery, and tend to swell in the presence of hydrocarbon natural gas constituents. The authors goal is to develop a family of microporous oxide films that offer permeability and selectivity exceeding those of polymer membranes, allowing gas membranes to compete with cryogenic and adsorption technologies for large-scale gas separation applications.

  9. Semiconductor-nanocrystal/conjugated polymer thin films

    DOEpatents

    Alivisatos, A. Paul; Dittmer, Janke J.; Huynh, Wendy U.; Milliron, Delia

    2010-08-17

    The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

  10. Semiconductor-nanocrystal/conjugated polymer thin films

    DOEpatents

    Alivisatos, A. Paul; Dittmer, Janke J.; Huynh, Wendy U.; Milliron, Delia

    2014-06-17

    The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

  11. Thin film-coated polymer webs

    DOEpatents

    Wenz, Robert P.; Weber, Michael F.; Arudi, Ravindra L.

    1992-02-04

    The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

  12. Low work function, stable thin films

    DOEpatents

    Dinh, Long N.; McLean, II, William; Balooch, Mehdi; Fehring, Jr., Edward J.; Schildbach, Marcus A.

    2000-01-01

    Generation of low work function, stable compound thin films by laser ablation. Compound thin films with low work function can be synthesized by simultaneously laser ablating silicon, for example, and thermal evaporating an alkali metal into an oxygen environment. For example, the compound thin film may be composed of Si/Cs/O. The work functions of the thin films can be varied by changing the silicon/alkali metal/oxygen ratio. Low work functions of the compound thin films deposited on silicon substrates were confirmed by ultraviolet photoelectron spectroscopy (UPS). The compound thin films are stable up to 500.degree. C. as measured by x-ray photoelectron spectroscopy (XPS). Tests have established that for certain chemical compositions and annealing temperatures of the compound thin films, negative electron affinity (NEA) was detected. The low work function, stable compound thin films can be utilized in solar cells, field emission flat panel displays, electron guns, and cold cathode electron guns.

  13. Thin film atomic hydrogen detectors

    NASA Technical Reports Server (NTRS)

    Gruber, C. L.

    1977-01-01

    Thin film and bead thermistor atomic surface recombination hydrogen detectors were investigated both experimentally and theoretically. Devices were constructed on a thin Mylar film substrate. Using suitable Wheatstone bridge techniques sensitivities of 80 microvolts/2x10 to the 13th power atoms/sec are attainable with response time constants on the order of 5 seconds.

  14. Thin film polymeric gel electrolytes

    DOEpatents

    Derzon, Dora K.; Arnold, Jr., Charles; Delnick, Frank M.

    1996-01-01

    Novel hybrid thin film electrolyte, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities .apprxeq.10.sup.-3 .OMEGA..sup.-1 cm.sup.-1 are useful as electrolytes for rechargeable lithium batteries.

  15. Hybrid thin-film amplifier

    NASA Technical Reports Server (NTRS)

    Cleveland, G.

    1977-01-01

    Miniature amplifier for bioelectronic instrumentation consumes only about 100 mW and has frequency response flat to within 0.5 dB from 0.14 to 450 Hz. Device consists of five thin film substrates, which contain eight operational amplifiers and seven field-effect transistor dice.

  16. Thin film polymeric gel electrolytes

    DOEpatents

    Derzon, D.K.; Arnold, C. Jr.; Delnick, F.M.

    1996-12-31

    Novel hybrid thin film electrolytes, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities {approx_equal}10{sup {minus}3}{Omega}{sup {minus}1} cm{sup {minus}1} are useful as electrolytes for rechargeable lithium batteries. 1 fig.

  17. Polycrystalline-thin-film thermophotovoltaic cells

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.

    1996-02-01

    Thermophotovoltaic (TPV) cells convert thermal energy to electricity. Modularity, portability, silent operation, absence of moving parts, reduced air pollution, rapid start-up, high power densities, potentially high conversion efficiencies, choice of a wide range of heat sources employing fossil fuels, biomass, and even solar radiation are key advantages of TPV cells in comparison with fuel cells, thermionic and thermoelectric convertors, and heat engines. The potential applications of TPV systems include: remote electricity supplies, transportation, co-generation, electric-grid independent appliances, and space, aerospace, and military power applications. The range of bandgaps for achieving high conversion efficiencies using low temperature (1000-2000 K) black-body or selective radiators is in the 0.5-0.75 eV range. Present high efficiency convertors are based on single crystalline materials such as In1-xGaxAs, GaSb, and Ga1-xInxSb. Several polycrystalline thin films such as Hg1-xCdxTe, Sn1-xCd2xTe2, and Pb1-xCdxTe, etc., have great potential for economic large-scale applications. A small fraction of the high concentration of charge carriers generated at high fluences effectively saturates the large density of defects in polycrystalline thin films. Photovoltaic conversion efficiencies of polycrystalline thin films and PV solar cells are comparable to single crystalline Si solar cells, e.g., 17.1% for CuIn1-xGaxSe2 and 15.8% for CdTe. The best recombination-state density Nt is in the range of 10-15-10-16 cm-3 acceptable for TPV applications. Higher efficiencies may be achieved because of the higher fluences, possibility of bandgap tailoring, and use of selective emitters such as rare earth oxides (erbia, holmia, yttria) and rare earth-yttrium aluminium garnets. As compared to higher bandgap semiconductors such as CdTe, it is easier to dope the lower bandgap semiconductors. TPV cell development can benefit from the more mature PV solar cell and opto

  18. Polycaprolactone thin films for retinal tissue engineering and drug delivery

    NASA Astrophysics Data System (ADS)

    Steedman, Mark Rory

    This dissertation focuses on the development of polycaprolactone thin films for retinal tissue engineering and drug delivery. We combined these thin films with techniques such as micro and nanofabrication to develop treatments for age-related macular degeneration (AMD), a disease that leads to the death of rod and cone photoreceptors. Current treatments are only able to slow or limit the progression of the disease, and photoreceptors cannot be regenerated or replaced by the body once lost. The first experiments presented focus on a potential treatment for AMD after photoreceptor death has occurred. We developed a polymer thin film scaffold technology to deliver retinal progenitor cells (RPCs) to the affected area of the eye. Earlier research showed that RPCs destined to become photoreceptors are capable of incorporating into a degenerated retina. In our experiments, we showed that RPC attachment to a micro-welled polycaprolactone (PCL) thin film surface enhanced the differentiation of these cells toward a photoreceptor fate. We then used our PCL thin films to develop a drug delivery device capable of sustained therapeutic release over a multi-month period that would maintain an effective concentration of the drug in the eye and eliminate the need for repeated intraocular injections. We first investigated the biocompatibility of PCL in the rabbit eye. We injected PCL thin films into the anterior chamber or vitreous cavity of rabbit eyes and monitored the animals for up to 6 months. We found that PCL thin films were well tolerated in the rabbit eye, showing no signs of chronic inflammation due to the implant. We then developed a multilayered thin film device containing a microporous membrane. We loaded these devices with lyophilized proteins and quantified drug elution for 10 weeks, finding that both bovine serum albumin and immunoglobulin G elute from these devices with zero order release kinetics. These experiments demonstrate that PCL is an extremely useful

  19. Slurry spin coating of thin film yttria stabilized zirconia/gadolinia doped ceria bi-layer electrolytes for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Kim, Hyun Joong; Kim, Manjin; Neoh, Ke Chean; Han, Gwon Deok; Bae, Kiho; Shin, Jong Mok; Kim, Gyu-Tae; Shim, Joon Hyung

    2016-09-01

    Thin ceramic bi-layered membrane comprising yttria-stabilized zirconia (YSZ) and gadolinia-doped ceria (GDC) is fabricated by the cost-effective slurry spin coating technique, and it is evaluated as an electrolyte of solid oxide fuel cells (SOFCs). It is demonstrated that the slurry spin coating method is capable of fabricating porous ceramic films by adjusting the content of ethyl-cellulose binders in the source slurry. The porous GDC layer deposited by spin coating under an optimal condition functions satisfactorily as a cathode-electrolyte interlayer in the test SOFC stack. A 2-μm-thick electrolyte membrane of the spin-coated YSZ/GDC bi-layer is successfully deposited as a dense and stable film directly on a porous NiO-YSZ anode support without any interlayers, and the SOFC produces power output over 200 mW cm-2 at 600 °C, with an open circuit voltage close to 1 V. Electrochemical impedance spectra analysis is conducted to evaluate the performance of the fuel cell components in relation with the microstructure of the spin-coated layers.

  20. Thin films and uses

    DOEpatents

    Baskaran, Suresh; Graff, Gordon L.; Song, Lin

    1998-01-01

    The invention provides a method for synthesizing a titanium oxide-containing film comprising the following steps: (a) preparing an aqueous solution of a titanium chelate with a titanium molarity in the range of 0.01M to 0.6M. (b) immersing a substrate in the prepared solution, (c) decomposing the titanium chelate to deposit a film on the substrate. The titanium chelate maybe decomposed acid, base, temperature or other means. A preferred method provides for the deposit of adherent titanium oxide films from C2 to C5 hydroxy carboxylic acids. In another aspect the invention is a novel article of manufacture having a titanium coating which protects the substrate against ultraviolet damage. In another aspect the invention provides novel semipermeable gas separation membranes, and a method for producing them.

  1. Flexible thin film magnetoimpedance sensors

    NASA Astrophysics Data System (ADS)

    Kurlyandskaya, G. V.; Fernández, E.; Svalov, A.; Burgoa Beitia, A.; García-Arribas, A.; Larrañaga, A.

    2016-10-01

    Magnetically soft thin film deposited onto polymer substrates is an attractive option for flexible electronics including magnetoimpedance (MI) applications. MI FeNi/Ti based thin film sensitive elements were designed and prepared using the sputtering technique by deposition onto rigid and flexible substrates at different deposition rates. Their structure, magnetic properties and MI were comparatively analyzed. The main structural features were sufficiently accurately reproduced in the case of deposition onto cyclo olefine polymer substrates compared to glass substrates for the same conditions. Although for the best condition (28 nm/min rate) of the deposition onto polymer a significant reduction of the MI field sensitivity was found satisfactory for sensor applications sensitivity: 45%/Oe was obtained for a frequency of 60 MHz.

  2. Thin film concentrator panel development

    NASA Technical Reports Server (NTRS)

    Zimmerman, D. K.

    1982-01-01

    The development and testing of a rigid panel concept that utilizes a thin film reflective surface for application to a low-cost point-focusing solar concentrator is discussed. It is shown that a thin film reflective surface is acceptable for use on solar concentrators, including 1500 F applications. Additionally, it is shown that a formed steel sheet substrate is a good choice for concentrator panels. The panel has good optical properties, acceptable forming tolerances, environmentally resistant substrate and stiffeners, and adaptability to low to mass production rates. Computer simulations of the concentrator optics were run using the selected reflector panel design. Experimentally determined values for reflector surface specularity and reflectivity along with dimensional data were used in the analysis. The simulations provided intercept factor and net energy into the aperture as a function of aperture size for different surface errors and pointing errors. Point source and Sun source optical tests were also performed.

  3. Ruthenium-Platinum Thin Film Analysis Using Grazing Incidence X-ray Diffraction

    SciTech Connect

    Jones, L.

    2004-09-03

    Ruthenium (Ru, Z = 44) is a Platinum Group Metal that has a standard hexagonal close packed (HCP) crystalline structure. Platinum (Pt, Z = 78) has a face-centered cubic (FCC) crystalline structure. When these metals are co-sputtered onto a silicon substrate, creating a few nm-thin film, they form an alloy with a combination of HCP and FCC structure. Direct methanol fuel cells rely on an anode catalyst to draw hydrogen from liquid methanol. Highly efficient fuel cells based on polymer electrolyte catalysts, known as proton-exchange membrane fuel cells, have been developed, but require large amounts of a costly platinum catalyst. Thin-film nanostructure bimetallic alloys have been produced to reduce the amount of expensive Platinum needed for catalysis, and also to improve the electrochemical properties of the catalyst. Supported RuPt particles have been shown to have superior activity as anode catalysts for methanol electro-oxidation and demonstrate an improvement in resistance to poisoning in comparison to unalloyed Pt. The percentage of Ruthenium in a RuPt thin film and the process by which the alloy is produced will dictate the crystalline structure, and thus the electrochemical properties of the film. Pure Ruthenium, Pure Platinum, and eight intermediate samples at differing percent composition of Ruthenium were characterized by their X-ray diffraction patterns. The incident beam is from the Stanford Synchrotron Radiation Laboratory beam and operates at approximately a 1.4 Angstrom wavelength. The results show that 0% Ru through 46.17% Ru exhibit a majority FCC structure, 56.07% Ru and 60.61% Ru are mixed phase, and from 67.03% Ru through 100% Ru, the samples exhibit a HCP structure.

  4. Thin-Film Power Transformers

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.

    1995-01-01

    Transformer core made of thin layers of insulating material interspersed with thin layers of ferromagnetic material. Flux-linking conductors made of thinner nonferromagnetic-conductor/insulator multilayers wrapped around core. Transformers have geometric features finer than those of transformers made in customary way by machining and mechanical pressing. In addition, some thin-film materials exhibit magnetic-flux-carrying capabilities superior to those of customary bulk transformer materials. Suitable for low-cost, high-yield mass production.

  5. Thin-film metal hydrides.

    PubMed

    Remhof, Arndt; Borgschulte, Andreas

    2008-12-01

    The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis.

  6. Advances in Thin Film Thermocouple Durability Under High Temperature and Pressure Testing Conditions

    NASA Technical Reports Server (NTRS)

    Martin, Lisa C.; Fralick, Gustave C.; Taylor, Keith F.

    1999-01-01

    Thin film thermocouples for measuring material surface temperature have been previously demonstrated on several material systems and in various hostile test environments. A well-developed thin film fabrication procedure utilizing shadow masking for patterning the sensors elements had produced thin films with sufficient durability for applications in high temperature and pressure environments that exist in air-breathing and hydrogen-fueled burner rig and engine test facilities. However, while shadow masking had been a reliable method for specimens with flat and gently curved surfaces, it had not been consistently reliable for use on test components with sharp contours. This work reports on the feasibility of utilizing photolithography processing for patterning thin film thermocouples. Because this patterning process required changes in the thin film deposition process from that developed for shadow masking, the effect of these changes on thin film adherence during burner rig testing was evaluated. In addition to the results of changing the patterning method, the effects on thin film adherence of other processes used in the thin film fabrication procedure is also presented.

  7. Characterization of the mechanical properties of freestanding platinum thin films

    NASA Astrophysics Data System (ADS)

    Abbas, Khawar

    Many MEMS devices utilize nanocrystalline thin metallic films as mechanical structures, in particular, micro switching devices where these films are used as Ohmic contacts. But the elastic and plastic properties of these thin films (thickness < 1mum) are significantly different from those of the bulk material. At these scales the volume fraction of material defects such as: grain boundaries, dislocations and interstitials become quite significant and become a chief contributor to the physical and mechanical material properties. In order to effectively design MEMS devices it is important that these material properties are explored and mechanical behavior of the structure they form be characterized. Popular thin film materials used in MEMS devices are Aluminum (Al), Copper (Cu), Nickel (Ni) and Gold (Au). Platinum has traditionally gained acceptance into the MEMS industry because of its chemical inertness and high temperature stability. However the mechanical properties of platinum remains the least exploited. Platinum has a high Young's Modulus (164 GPa, for bulk) and high melting temperature (1768 °C) and therefore can be used as a 'thin film' structure (cantilever, a bridge or a membrane) in high temperature environments with high resistance to mechanical failure. The physical size of these thin film structure make it very difficult to handle them and employ traditional mechanical testing methodologies and techniques and therefore require custom test platforms. One such recently developed platform is presented in this dissertation. The test platform is comprised of a microfabricated cascaded thermal actuator system and test specimen. The cascaded thermal actuator system is capable of providing tens of microns of displacement and tens of milli-Newton forces simultaneously while applying a relatively low temperature gradient across the test specimen. The dimensions of the platform make its use possible in both the SEM/TEM environments and on a probe station under

  8. Corrugated Membrane Fuel Cell Structures

    SciTech Connect

    Grot, Stephen

    2013-09-30

    One of the most challenging aspects of traditional PEM fuel cell stacks is the difficulty achieving the platinum catalyst utilization target of 0.2 gPt/kWe set forth by the DOE. Good catalyst utilization can be achieved with state-of-the-art catalyst coated membranes (CCM) when low catalyst loadings (<0.3 mg/cm2) are used at a low current. However, when low platinum loadings are used, the peak power density is lower than conventional loadings, requiring a larger total active area and a larger bipolar plate. This results in a lower overall stack power density not meeting the DOE target. By corrugating the fuel cell membrane electrode structure, Ion Power?s goal is to realize both the Pt utilization targets as well as the power density targets of the DOE. This will be achieved by demonstrating a fuel cell single cell (50 cm2) with a twofold increase in the membrane active area over the geometric area of the cell by corrugating the MEA structure. The corrugating structure must be able to demonstrate the target properties of < 10 mOhm-cm2 electrical resistance at > 20 psi compressive strength over the active area, in combination with offering at least 80% of power density that can be achieved by using the same MEA in a flat plate structure. Corrugated membrane fuel cell structures also have the potential to meet DOE power density targets by essentially packaging more membrane area into the same fuel cell volume as compared to conventional stack constructions.

  9. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUELS PLANTS

    SciTech Connect

    Shane E. Roark; Anthony F. Sammells; Richard Mackay; Stewart Schesnack; Scott Morrison; Thomas A. Zirbel; Thomas F. Barton; Sara L. Rolfe; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-07-31

    Eltron Research Inc. and team members CoorsTek, Sued Chemie, and Argonne National Laboratory are developing an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. This project was motivated by the National Energy Technology Laboratory (NETL) Vision 21 initiative, which seeks to economically eliminate environmental concerns associated with the use of fossil fuels. Currently, this project is focusing on four basic categories of dense membranes: (1) mixed conducting ceramic/ceramic composites, (2) mixed conducting ceramic/metal (cermet) composites, (3) cermets with hydrogen permeable metals, and (4) layered composites containing hydrogen permeable alloys. Ultimately, these materials must enable hydrogen separation at practical rates under ambient and high-pressure conditions, without deactivation in the presence of feedstream components such as carbon dioxide, water, and sulfur. This report presents hydrogen permeation data during long term tests and tests at high pressure in addition to progress with cermet, ceramic/ceramic, and thin film membranes.

  10. Method of producing amorphous thin films

    DOEpatents

    Brusasco, Raymond M.

    1992-01-01

    Disclosed is a method of producing thin films by sintering which comprises: a. coating a substrate with a thin film of an inorganic glass forming parulate material possessing the capability of being sintered, and b. irridiating said thin film of said particulate material with a laser beam of sufficient power to cause sintering of said material below the temperature of liquidus thereof. Also disclosed is the article produced by the method claimed.

  11. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  12. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    Marshall Space Flight Center (MSFC) is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using Electron Cyclotron Resonance Chemical Vapor Deposition (ECRCVD) to deposit hard thin film on stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  13. Beryllium thin films for resistor applications

    NASA Technical Reports Server (NTRS)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  14. Thin film buried anode battery

    DOEpatents

    Lee, Se-Hee; Tracy, C. Edwin; Liu, Ping

    2009-12-15

    A reverse configuration, lithium thin film battery (300) having a buried lithium anode layer (305) and process for making the same. The present invention is formed from a precursor composite structure (200) made by depositing electrolyte layer (204) onto substrate (201), followed by sequential depositions of cathode layer (203) and current collector (202) on the electrolyte layer. The precursor is subjected to an activation step, wherein a buried lithium anode layer (305) is formed via electroplating a lithium anode layer at the interface of substrate (201) and electrolyte film (204). The electroplating is accomplished by applying a current between anode current collector (201) and cathode current collector (202).

  15. Thin film solar energy collector

    DOEpatents

    Aykan, Kamran; Farrauto, Robert J.; Jefferson, Clinton F.; Lanam, Richard D.

    1983-11-22

    A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

  16. Post-annealing of thin-film yttria stabilized zirconia electrolytes for anode-supported low-temperature solid oxide fuel cells.

    PubMed

    Bae, Jiwoong; Chang, Ikwhang; Kang, Sungmin; Hong, Soonwook; Cha, Suk Won; Kim, Young Beom

    2014-12-01

    The effects of a post-annealing treatment on the performance of low-temperature solid oxide fuel cells (LT-SOFCs) were investigated. Nickel oxide-samarium doped ceria (NiO-SDC) anodes and yttria stabilized zirconia (YSZ) electrolytes were deposited on anodized aluminum oxide (AAO) membranes by RF sputtering and DC reactive sputtering, respectively. The half-cell of YSZ/NiO-SDC was then heat-treated at 600 degrees C for 10 h, and a porous platinum (Pt) cathode was deposited on the annealed YSZ/NiO-SDC structure by DC magnetron sputtering. Electrochemical impedance spectroscopy (EIS) analysis revealed a significant decrease in the ohmic resistance and a slight increase in the cathodic impedance. Such a result may be attributed to the increased grain size and enhanced crystallinity of the YSZ electrolyte after the heat treatment. The maximum power density observed for the heat-treated cell was 35 mW/cm2 at 450 degrees C, more than three times higher than the 10 mW/cm2 value obtained for the as-deposited cell.

  17. Spray- and spin-assisted layer-by-layer assembly of copper nanoparticles on thin-film composite reverse osmosis membrane for biofouling mitigation.

    PubMed

    Ma, Wen; Soroush, Adel; Van Anh Luong, Tran; Brennan, Gregory; Rahaman, Md Saifur; Asadishad, Bahareh; Tufenkji, Nathalie

    2016-08-01

    Copper nanoparticles (CuNPs) have long been considered as highly effective biocides; however, the lack of suitable methods for loading CuNPs onto polymeric membranes is recognized as being one of the primary reasons for the limited research concerning their application in membrane industries. A highly efficient spray- and spin-assisted layer-by-layer (SSLbL) method was developed to functionalize the TFC polyamide RO membranes with controllable loading of CuNPs for biofouling control. The SSLbL method was able to produce a uniform bilayer of polyethyleneimine-coated CuNPs and poly(acrylic) acid in less than 1 min, which is far more efficient than the traditional dipping approach (25-60 min). The successful loading of CuNPs onto the membrane surface was confirmed by XPS analysis. Increasing the number of bilayers from 2 to 10 led to an increased quantity of CuNPs on the membrane surface, from 1.75 to 23.7 μg cm(-2). Multi-layer coating exhibited minor impact on the membrane water permeation flux (13.3% reduction) while retaining the original salt rejection ability. Both static bacterial inactivation and cross-flow filtration tests demonstrated that CuNPs could significantly improve anti-biofouling property of a polyamide membrane and effectively inhibit the permeate flux reduction caused by bacterial deposition on the membrane surface. Once depleted, CuNPs can also be potentially regenerated on the membrane surface via the same SSLbL method.

  18. Spray- and spin-assisted layer-by-layer assembly of copper nanoparticles on thin-film composite reverse osmosis membrane for biofouling mitigation.

    PubMed

    Ma, Wen; Soroush, Adel; Van Anh Luong, Tran; Brennan, Gregory; Rahaman, Md Saifur; Asadishad, Bahareh; Tufenkji, Nathalie

    2016-08-01

    Copper nanoparticles (CuNPs) have long been considered as highly effective biocides; however, the lack of suitable methods for loading CuNPs onto polymeric membranes is recognized as being one of the primary reasons for the limited research concerning their application in membrane industries. A highly efficient spray- and spin-assisted layer-by-layer (SSLbL) method was developed to functionalize the TFC polyamide RO membranes with controllable loading of CuNPs for biofouling control. The SSLbL method was able to produce a uniform bilayer of polyethyleneimine-coated CuNPs and poly(acrylic) acid in less than 1 min, which is far more efficient than the traditional dipping approach (25-60 min). The successful loading of CuNPs onto the membrane surface was confirmed by XPS analysis. Increasing the number of bilayers from 2 to 10 led to an increased quantity of CuNPs on the membrane surface, from 1.75 to 23.7 μg cm(-2). Multi-layer coating exhibited minor impact on the membrane water permeation flux (13.3% reduction) while retaining the original salt rejection ability. Both static bacterial inactivation and cross-flow filtration tests demonstrated that CuNPs could significantly improve anti-biofouling property of a polyamide membrane and effectively inhibit the permeate flux reduction caused by bacterial deposition on the membrane surface. Once depleted, CuNPs can also be potentially regenerated on the membrane surface via the same SSLbL method. PMID:27161885

  19. Impact of food to microorganism (F/M) ratio and colloidal chemical oxygen demand on nitrification performance of a full-scale membrane bioreactor treating thin film transistor liquid crystal display wastewater.

    PubMed

    Wu, Yi-Ju; Whang, Liang-Ming; Chang, Ming-Yu; Fukushima, Toshikazu; Lee, Ya-Chin; Cheng, Sheng-Shung; Hsu, Shu-Fu; Chang, Cheng-Huey; Shen, Wason; Yang, Charn-Yi; Fu, Ryan; Tsai, Tsair-Yuan

    2013-08-01

    This study investigated impact of food to microorganism (F/M) ratio and colloidal chemical oxygen demand (COD) on nitrification performance in one full-scale membrane bioreactor (MBR) treating monoethanolamine (MEA)/dimethyl sulfoxide (DMSO)-containing thin film transistor liquid crystal display (TFT-LCD) wastewater. Poor nitrification was observed under high organic loading and high colloidal COD conditions, suggesting that high F/M ratio and colloidal COD situations should be avoided to minimize their negative impacts on nitrification. According to the nonmetric multidimensional scaling (NMS) statistical analyses on terminal restriction fragment length polymorphism (T-RFLP) results of ammonia monooxygenase (amoA) gene, the occurrence of Nitrosomonas oligotropha-like ammonia oxidizing bacteria (AOB) was positively related to successful nitrification in the MBR systems, while Nitrosomonas europaea-like AOB was positively linked to nitrification rate, which can be attributed to the high influent total nitrogen condition. Furthermore, Nitrobacter- and Nitrospira-like nitrite oxidizing bacteria (NOB) were both abundant in the MBR systems, but the continuously low nitrite environment is likely to promote the growth of Nitrospira-like NOB.

  20. Laser deposition of SmCo thin film and coating on different substrates

    NASA Astrophysics Data System (ADS)

    Allocca, L.; Bonavolontà, C.; Giardini, A.; Lopizzo, T.; Morone, A.; Valentino, M.; Verrastro, M. F.; Viggiano, V.

    2008-10-01

    Thin films and coatings of permanent magnetic materials are very important for different electronic and micromechanical applications. This paper deals with the fabrication, using pulsed laser deposition (PLD) technique, of good quality magnetic SmCo thin films on polycarbonate, steel, silicon and amorphous quartz substrates, for low cost electronic applications like radio frequency identification (RFID) antennas and electromechanical devices for fuel feeding control in the automotive. X-ray fluorescence and magnetic scanning measurements using giant magneto-resistive (GMR) sensors have been performed to study the functional magnetic properties of the deposited thin films.

  1. Thin-Film Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Lowe, Roland A.

    1993-01-01

    Direct conversion of thermal energy into electrical energy using a photovoltaic cell is called thermophotovoltaic energy conversion. One way to make this an efficient process is to have the thermal energy source be an efficient selective emitter of radiation. The emission must be near the band-gap energy of the photovoltaic cell. One possible method to achieve an efficient selective emitter is the use of a thin film of rare-earth oxides. The determination of the efficiency of such an emitter requires analysis of the spectral emittance of the thin film including scattering and reflectance at the vacuum-film and film-substrate interfaces. Emitter efficiencies (power emitted in emission band/total emitted power) in the range 0.35-0.7 are predicted. There is an optimum optical depth to obtain maximum efficiency. High emitter efficiencies are attained only for low (less than 0.05) substrate emittance values, both with and without scattering. The low substrate emittance required for high efficiency limits the choice of substrate materials to highly reflective metals or high-transmission materials such as sapphire.

  2. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect

    Shane E. Roark; Tony F. Sammells; Adam Calihman; Andy Girard; Pamela M. Van Calcar; Richard Mackay; Tom Barton; Sara Rolfe

    2001-01-30

    membranes of this thickness. The sintered membranes were greater than 95% dense, but the phase purity decreased with increasing dopant concentration. The quantity of dopant incorporated into the perovskite phase was roughly constant, with excess dopant forming an additional phase. Composite materials with distinct ceramic and metallic phases, and thin film perovskites (100 {micro}m) also were successfully prepared, but have not yet been tested for hydrogen transport. Finally, porous platinum was identified as a excellent catalyst for evaluation of membrane materials, however, lower cost nickel catalyst systems are being developed.

  3. Thin films of mixed metal compounds

    DOEpatents

    Mickelsen, Reid A.; Chen, Wen S.

    1985-01-01

    A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

  4. Design of aromatic thermosetting copolyester compositions and blends for thin film applications

    NASA Astrophysics Data System (ADS)

    Xu, Kun

    performance polymers. To our knowledge, all other studies on this phenomenon have been limited to model polymers. In the second approach, a hyperbranched copoly(imide-ester) (HBPIE) has been synthesized and characterized. Most interestingly, the HBPIE has a surface area of 83 m2/g, due to their intrinsic and stable microporosity (pore size 12.7 A). Further, HBPIE thin films displays an intermediate dielectric constant (3.6) and high dielectric breakdown strength (330 V/mum). HBPIE thin films could find potential application as reverse osmosis membranes or dielectric thin films in capacitors.

  5. Nanoscale Thermoelectrics: A Study of the Absolute Seebeck Coefficient of Thin Films

    NASA Astrophysics Data System (ADS)

    Mason, Sarah J.

    The worlds demand for energy is ever increasing. Likewise, the environmental impact of climate change due generating that energy through combustion of fossil fuels is increasingly alarming. Due to these factors new sources of renewable energies are constantly being sought out. Thermoelectric devices have the ability to generate clean, renewable, energy out of waste heat. However promising that is, their inefficiency severely inhibits applicability and practical use. The usefulness of a thermoelectric material increases with the dimensionless quantity, ZT, which depends on the Seebeck coefficient and electrical and thermal conductivity. These characteristic material parameters have interdependent energy transport contributions that classically prohibit the optimization of one with out the detriment of another. Encouraging advancements of ZT have occurred in the past ten years due to the decoupling of the thermal and electrical conductivity. Further advancements are necessary in order to produce applicable devices. One auspicious way of decoupling or tuning energy transport properties, is through size reduction to the nanoscale. However, with reduced dimensions come complications in measuring material properties. Measurements of properties such as the Seebeck coefficient, S, are primarily contingent upon the measurement apparatus. The Seebeck coefficient is defined as the amount of voltage generated by a thermal gradient. Measuring a thermally generated voltage by traditional methods gives, the voltage measured as a linear function of the Seebeck coefficient of the leads and of the material being tested divided by the applied thermal gradient. If accurate values of the Seebeck coefficients of the leads are available, simple subtraction provides the answer. This is rarely the case in nanoscale measurement devices with leads exclusively made from thin film materials that do not have well known bulk-like thermopower values. We have developed a technique to directly

  6. Phosphorus-doped glass proton exchange membranes for low temperature direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Prakash, Shruti; Mustain, William E.; Park, SeongHo; Kohl, Paul A.

    Phosphorus-doped silicon dioxide thin films were used as ion exchange membranes in low temperature proton exchange membrane fuel cells. Phosphorus-doped silicon dioxide glass (PSG) was deposited via plasma-enhanced chemical vapor deposition (PECVD). The plasma deposition of PSG films allows for low temperature fabrication that is compatible with current microelectronic industrial processing. SiH 4, PH 3 and N 2O were used as the reactant gases. The effect of plasma deposition parameters, substrate temperature, RF power, and chamber pressure, on the ionic conductivity of the PSG films is elucidated. PSG conductivities as high as 2.54 × 10 -4 S cm -1 were realized, which is 250 times higher than the conductivity of pure SiO 2 films (1 × 10 -6 S cm -1) under identical deposition conditions. The higher conductivity films were deposited at low temperature, moderate pressure, limited reactant gas flow rate, and high RF power.

  7. A monolithic thin film electrochromic window

    SciTech Connect

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K.; Wei, G.; Yu, P.C.

    1991-12-31

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors` institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  8. A monolithic thin film electrochromic window

    SciTech Connect

    Goldner, R.B.; Arntz, F.O.; Berera, G.; Haas, T.E.; Wong, K.K. . Electro-Optics Technology Center); Wei, G. ); Yu, P.C. )

    1991-01-01

    Three closely related thin film solid state ionic devices that are potentially important for applications are: electrochromic smart windows, high energy density thin film rechargeable batteries, and thin film electrochemical sensors. Each usually has at least on mixed ion/electron conductor, an electron-blocking ion conductor, and an ion-blocking electron conductor, and many of the technical issues associated with thin film solid state ionics are common to all three devices. Since the electrochromic window has the added technical requirement of electrically-controlled optical modulation, (over the solar spectrum), and since research at the authors' institution has focused primarily on the window structure, this paper will address the electrochromic window, and particularly a monolithic variable reflectivity electrochromic window, as an illustrative example of some of the challenges and opportunities that are confronting the thin film solid state ionics community. 33 refs.

  9. Zinc oxide thin film acoustic sensor

    SciTech Connect

    Mohammed, Ali Jasim; Salih, Wafaa Mahdi; Hassan, Marwa Abdul Muhsien; Nusseif, Asmaa Deiaa; Kadhum, Haider Abdullah; Mansour, Hazim Louis

    2013-12-16

    This paper reports the implementation of (750 nm) thickness of Zinc Oxide (ZnO) thin film for the piezoelectric pressure sensors. The film was prepared and deposited employing the spray pyrolysis technique. XRD results show that the growth preferred orientation is the (002) plane. A polycrystalline thin film (close to mono crystallite like) was obtained. Depending on the Scanning Electron Microscopy photogram, the film homogeneity and thickness were shown. The resonance frequency measured (about 19 kHz) and the damping coefficient was calculated and its value was found to be about (2.5538), the thin film be haves as homogeneous for under and over damped. The thin film pressure sensing was approximately exponentially related with frequency, the thin film was observed to has a good response for mechanical stresses also it is a good material for the piezoelectric properties.

  10. Structurally-driven Enhancement of Thermoelectric Properties within Poly(3,4-ethylenedioxythiophene) thin Films

    NASA Astrophysics Data System (ADS)

    Petsagkourakis, Ioannis; Pavlopoulou, Eleni; Portale, Giuseppe; Kuropatwa, Bryan A.; Dilhaire, Stefan; Fleury, Guillaume; Hadziioannou, Georges

    2016-07-01

    Due to the rising need for clean energy, thermoelectricity has raised as a potential alternative to reduce dependence on fossil fuels. Specifically, thermoelectric devices based on polymers could offer an efficient path for near-room temperature energy harvesters. Thus, control over thermoelectric properties of conducting polymers is crucial and, herein, the structural, electrical and thermoelectric properties of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films doped with p-toluenesulfonate (Tos) molecules were investigated with regards to thin film processing. PEDOT:Tos thin films were prepared by in-situ polymerization of (3,4-ethylenedioxythiophene) monomers in presence of iron(III) p-toluenesulfonate with different co-solvents in order to tune the film structure. While the Seebeck coefficient remained constant, a large improvement in the electrical conductivity was observed for thin films processed with high boiling point additives. The increase of electrical conductivity was found to be solely in-plane mobility-driven. Probing the thin film structure by Grazing Incidence Wide Angle X-ray Scattering has shown that this behavior is dictated by the structural properties of the PEDOT:Tos films; specifically by the thin film crystallinity combined to the preferential edge-on orientation of the PEDOT crystallites. Consequentially enhancement of the power factor from 25 to 78.5 μW/mK2 has been readily obtained for PEDOT:Tos thin films following this methodology.

  11. Structurally-driven Enhancement of Thermoelectric Properties within Poly(3,4-ethylenedioxythiophene) thin Films

    PubMed Central

    Petsagkourakis, Ioannis; Pavlopoulou, Eleni; Portale, Giuseppe; Kuropatwa, Bryan A.; Dilhaire, Stefan; Fleury, Guillaume; Hadziioannou, Georges

    2016-01-01

    Due to the rising need for clean energy, thermoelectricity has raised as a potential alternative to reduce dependence on fossil fuels. Specifically, thermoelectric devices based on polymers could offer an efficient path for near-room temperature energy harvesters. Thus, control over thermoelectric properties of conducting polymers is crucial and, herein, the structural, electrical and thermoelectric properties of poly(3,4-ethylenedioxythiophene) (PEDOT) thin films doped with p-toluenesulfonate (Tos) molecules were investigated with regards to thin film processing. PEDOT:Tos thin films were prepared by in-situ polymerization of (3,4-ethylenedioxythiophene) monomers in presence of iron(III) p-toluenesulfonate with different co-solvents in order to tune the film structure. While the Seebeck coefficient remained constant, a large improvement in the electrical conductivity was observed for thin films processed with high boiling point additives. The increase of electrical conductivity was found to be solely in-plane mobility-driven. Probing the thin film structure by Grazing Incidence Wide Angle X-ray Scattering has shown that this behavior is dictated by the structural properties of the PEDOT:Tos films; specifically by the thin film crystallinity combined to the preferential edge-on orientation of the PEDOT crystallites. Consequentially enhancement of the power factor from 25 to 78.5 μW/mK2 has been readily obtained for PEDOT:Tos thin films following this methodology. PMID:27470637

  12. Manufacturing polymer thin films in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Vera, Ivan

    1987-01-01

    This project represents Venezuela's first scientific experiment in space. The apparatus for the automatic casting of two polymer thin films will be contained in NASA's Payload No. G-559 of the Get Away Special program for a future orbital space flight in the U.S. Space Shuttle. Semi-permeable polymer membranes have important applications in a variety of fields, such as medicine, energy, and pharmaceuticals and in general fluid separation processes, such as reverse osmosis, ultrafiltration, and electrodialysis. The casting of semi-permeable membranes in space will help to identify the roles of convection in determining the structure of these membranes.

  13. Thin film bioreactors in space.

    PubMed

    Hughes-Fulford, M; Scheld, H W

    1989-01-01

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers us an opportunity to learn more about basic biological systems with one important variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would enable us to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  14. Thin film bioreactors in space

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.; Scheld, H. W.

    1989-01-01

    Studies from the Skylab, SL-3 and D-1 missions have demonstrated that biological organisms grown in microgravity have changes in basic cellular functions such as DNA, mRNA and protein synthesis, cytoskeleton synthesis, glucose utilization, and cellular differentiation. Since microgravity could affect prokaryotic and eukaryotic cells at a subcellular and molecular level, space offers an opportunity to learn more about basic biological systems with one inmportant variable removed. The thin film bioreactor will facilitate the handling of fluids in microgravity, under constant temperature and will allow multiple samples of cells to be grown with variable conditions. Studies on cell cultures grown in microgravity would make it possible to identify and quantify changes in basic biological function in microgravity which are needed to develop new applications of orbital research and future biotechnology.

  15. BDS thin film damage competition

    SciTech Connect

    Stolz, C J; Thomas, M D; Griffin, A J

    2008-10-24

    A laser damage competition was held at the 2008 Boulder Damage Symposium in order to determine the current status of thin film laser resistance within the private, academic, and government sectors. This damage competition allows a direct comparison of the current state-of-the-art of high laser resistance coatings since they are all tested using the same damage test setup and the same protocol. A normal incidence high reflector multilayer coating was selected at a wavelength of 1064 nm. The substrates were provided by the submitters. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials, and layer count will also be shared.

  16. Wrinkle motifs in thin films

    PubMed Central

    Budrikis, Zoe; Sellerio, Alessandro L.; Bertalan, Zsolt; Zapperi, Stefano

    2015-01-01

    On length scales from nanometres to metres, partial adhesion of thin films with substrates generates a fascinating variety of patterns, such as ‘telephone cord’ buckles, wrinkles, and labyrinth domains. Although these patterns are part of everyday experience and are important in industry, they are not completely understood. Here, we report simulation studies of a previously-overlooked phenomenon in which pairs of wrinkles form avoiding pairs, focusing on the case of graphene over patterned substrates. By nucleating and growing wrinkles in a controlled way, we characterize how their morphology is determined by stress fields in the sheet and friction with the substrate. Our simulations uncover the generic behaviour of avoiding wrinkle pairs that should be valid at all scales. PMID:25758174

  17. Wrinkle motifs in thin films

    NASA Astrophysics Data System (ADS)

    Budrikis, Zoe; Sellerio, Alessandro L.; Bertalan, Zsolt; Zapperi, Stefano

    2015-03-01

    On length scales from nanometres to metres, partial adhesion of thin films with substrates generates a fascinating variety of patterns, such as `telephone cord' buckles, wrinkles, and labyrinth domains. Although these patterns are part of everyday experience and are important in industry, they are not completely understood. Here, we report simulation studies of a previously-overlooked phenomenon in which pairs of wrinkles form avoiding pairs, focusing on the case of graphene over patterned substrates. By nucleating and growing wrinkles in a controlled way, we characterize how their morphology is determined by stress fields in the sheet and friction with the substrate. Our simulations uncover the generic behaviour of avoiding wrinkle pairs that should be valid at all scales.

  18. Amide Link Scission in the Polyamide Active Layers of Thin-Film Composite Membranes upon Exposure to Free Chlorine: Kinetics and Mechanisms.

    PubMed

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2015-10-20

    The volume-averaged amide link scission in the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine was quantified at a variety of free chlorine exposure times, concentrations, and pH and rinsing conditions. The results showed that (i) hydroxyl ions are needed for scission to occur, (ii) hydroxide-induced amide link scission is a strong function of exposure to hypochlorous acid, (iii) the ratio between amide links broken and chlorine atoms taken up increased with the chlorination pH and reached a maximum of ∼25%, (iv) polyamide disintegration occurs when high free chlorine concentrations, alkaline conditions, and high exposure times are combined, (v) amide link scission promotes further chlorine uptake, and (vi) scission at the membrane surface is unrepresentative of volume-averaged scission in the active layer. Our observations are consistent with previously proposed mechanisms describing amide link scission as a result of the hydrolysis of the N-chlorinated amidic N-C bond due to nucleophilic attack by hydroxyl ions. This study increases the understanding of the physicochemical changes that could occur for membranes in treatment plants using chlorine as an upstream disinfectant and the extent and rate at which those changes would occur. PMID:26394532

  19. Amide Link Scission in the Polyamide Active Layers of Thin-Film Composite Membranes upon Exposure to Free Chlorine: Kinetics and Mechanisms.

    PubMed

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2015-10-20

    The volume-averaged amide link scission in the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine was quantified at a variety of free chlorine exposure times, concentrations, and pH and rinsing conditions. The results showed that (i) hydroxyl ions are needed for scission to occur, (ii) hydroxide-induced amide link scission is a strong function of exposure to hypochlorous acid, (iii) the ratio between amide links broken and chlorine atoms taken up increased with the chlorination pH and reached a maximum of ∼25%, (iv) polyamide disintegration occurs when high free chlorine concentrations, alkaline conditions, and high exposure times are combined, (v) amide link scission promotes further chlorine uptake, and (vi) scission at the membrane surface is unrepresentative of volume-averaged scission in the active layer. Our observations are consistent with previously proposed mechanisms describing amide link scission as a result of the hydrolysis of the N-chlorinated amidic N-C bond due to nucleophilic attack by hydroxyl ions. This study increases the understanding of the physicochemical changes that could occur for membranes in treatment plants using chlorine as an upstream disinfectant and the extent and rate at which those changes would occur.

  20. Thin films under chemical stress

    SciTech Connect

    Not Available

    1991-01-01

    The goal of work on this project has been develop a set of experimental tools to allow investigators interested in transport, binding, and segregation phenomena in composite thin film structures to study these phenomena in situ. Work to-date has focuses on combining novel spatially-directed optical excitation phenomena, e.g. waveguide eigenmodes in thin dielectric slabs, surface plasmon excitations at metal-dielectric interfaces, with standard spectroscopies to understand dynamic processes in thin films and at interfaces. There have been two main scientific thrusts in the work and an additional technical project. In one thrust we have sought to develop experimental tools which will allow us to understand the chemical and physical changes which take place when thin polymer films are placed under chemical stress. In principle this stress may occur because the film is being swelled by a penetrant entrained in solvent, because interfacial reactions are occurring at one or more boundaries within the film structure, or because some component of the film is responding to an external stimulus (e.g. pH, temperature, electric field, or radiation). However all work to-date has focused on obtaining a clearer understanding penetrant transport phenomena. The other thrust has addressed the kinetics of adsorption of model n-alkanoic acids from organic solvents. Both of these thrusts are important within the context of our long-term goal of understanding the behavior of composite structures, composed of thin organic polymer films interspersed with Langmuir-Blodgett (LB) and self-assembled monolayers. In addition there has been a good deal of work to develop the local technical capability to fabricate grating couplers for optical waveguide excitation. This work, which is subsidiary to the main scientific goals of the project, has been successfully completed and will be detailed as well. 41 refs., 10 figs.

  1. Operando and in situ X-ray spectroscopies of degradation in La0.6Sr0.4Co0.2Fe0.8O(3-δ) thin film cathodes in fuel cells.

    PubMed

    Lai, Samson Y; Ding, Dong; Liu, Mingfei; Liu, Meilin; Alamgir, Faisal M

    2014-11-01

    Information from ex situ characterization can fall short in describing complex materials systems simultaneously exposed to multiple external stimuli. Operando X-ray absorption spectroscopy (XAS) was used to probe the local atomistic and electronic structure of specific elements in a La0.6Sr0.4Co0.2Fe0.8O(3-δ) (LSCF) thin film cathode exposed to air contaminated with H2O and CO2 under operating conditions. While impedance spectroscopy showed that the polarization resistance of the LSCF cathode increased upon exposure to both contaminants at 750 °C, XAS near-edge and extended fine structure showed that the degree of oxidation for Fe and Co decreases with increasing temperature. Synchrotron-based X-ray photoelectron spectroscopy tracked the formation and removal of a carbonate species, a Co phase, and different oxygen moieties as functions of temperature and gas. The combined information provides insight into the fundamental mechanism by which H2O and CO2 cause degradation in the cathode of solid oxide fuel cells. PMID:25205041

  2. Influence of a platinum functional layer on a Ni-Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} anode for thin-film solid oxide fuel cells

    SciTech Connect

    Kang, Sungmin; Cha, Suk Won E-mail: swcha@snu.ac.kr; Chang, Ikwhang; Kim, Young-Beom E-mail: swcha@snu.ac.kr

    2015-09-15

    A Pt functional layer was deposited between a Ni-Ce{sub 0.9}Gd{sub 0.1}O{sub 1.95} (50 wt. % Ni) anode and an 8 mol. % yttria-stabilized zirconia electrolyte in order to enhance the performance of a thin film solid oxide fuel cell. By inserting this ultrathin functional layer, the ohmic impedance of the single cell was significantly reduced, and the maximum power density was increased by a factor of ∼1.55. However, excessive deposition of the Pt functional layer caused ionic conduction pathway blocking between the yttria-stabilized zirconia and Ni-Gd{sub 0.1}Ce{sub 0.9}O{sub 1.95} (Ni-GDC), deactivating the Ni-GDC as a mixed ionic and electronic conducting anode. As a result, both the ohmic impedance and anodic faradaic impedance were increased after introduction of excessive Pt functional layer, and the maximum power density was also reduced.

  3. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect

    Shane E. Roark; Anthony F. Sammells; Richard Mackay; Stewart R. Schesnack; Scott R. Morrison; Thomas F. Barton; Sara L. Rolfe; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Aaron L. Wagner; Jon P. Wagner

    2003-10-30

    -months of continuous operation, and permeation results as a function of operating conditions at high pressure for layered composite membranes. Additional progress with cermet and thin film membranes also is presented.

  4. Fuel-Cell Structure Prevents Membrane Drying

    NASA Technical Reports Server (NTRS)

    Mcelroy, J.

    1986-01-01

    Embossed plates direct flows of reactants and coolant. Membrane-type fuel-cell battery has improved reactant flow and heat removal. Compact, lightweight battery produces high current and power without drying of membranes.

  5. Method for making surfactant-templated, high-porosity thin films

    DOEpatents

    Brinker, C. Jeffrey; Lu, Yunfeng; Fan, Hongyou

    2001-01-01

    An evaporation-induced self-assembly method to prepare a surfactant-templated thin film by mixing a silica sol, a surfactant, and a hydrophobic polymer and then evaporating a portion of the solvent during coating onto a substrate and then heating to form a liquid-phase, thin film material with a porosity greater than approximately 50 percent. The high porosity thin films can have dielectric constants less than 2 to be suitable for applications requiring low-dielectric constants. An interstitial compound can be added to the mixture, with the interstitial compound either covalently bonded to the pores or physically entrapped within the porous structure. The selection of the interstitial compound provides a means for developing thin films for applications including membranes, sensors, low dielectric constant films, photonic materials and optical hosts.

  6. High-Temperature, Thin-Film Ceramic Thermocouples Developed

    NASA Technical Reports Server (NTRS)

    Sayir, Ali; Blaha, Charles A.; Gonzalez, Jose M.

    2005-01-01

    To enable long-duration, more distant human and robotic missions for the Vision for Space Exploration, as well as safer, lighter, quieter, and more fuel efficient vehicles for aeronautics and space transportation, NASA is developing instrumentation and material technologies. The high-temperature capabilities of thin-film ceramic thermocouples are being explored at the NASA Glenn Research Center by the Sensors and Electronics Branch and the Ceramics Branch in partnership with Case Western Reserve University (CWRU). Glenn s Sensors and Electronics Branch is developing thin-film sensors for surface measurement of strain, temperature, heat flux, and surface flow in propulsion system research. Glenn s Ceramics Branch, in conjunction with CWRU, is developing structural and functional ceramic technology for aeropropulsion and space propulsion.

  7. In-membrane micro fuel cell

    DOEpatents

    Omosebi, Ayokunle; Besser, Ronald

    2016-09-06

    An in-membrane micro fuel cell comprises an electrically-insulating membrane that is permissive to the flow of cations, such as protons, and a pair of electrodes deposited on channels formed in the membrane. The channels are arranged as conduits for fluids, and define a membrane ridge between the channels. The electrodes are porous and include catalysts for promoting the liberation of a proton and an electron from a chemical species and/or or the recombination of a proton and an electron with a chemical specie. The fuel cell may be provided a biosensor, an electrochemical sensor, a microfluidic device, or other microscale devices fabricated in the fuel cell membrane.

  8. Macro stress mapping on thin film buckling

    SciTech Connect

    Goudeau, P.; Villain, P.; Renault, P.-O.; Tamura, N.; Celestre, R.S.; Padmore, H.A.

    2002-11-06

    Thin films deposited by Physical Vapour Deposition techniques on substrates generally exhibit large residual stresses which may be responsible of thin film buckling in the case of compressive stresses. Since the 80's, a lot of theoretical work has been done to develop mechanical models but only a few experimental work has been done on this subject to support these theoretical approaches and nothing concerning local stress measurement mainly because of the small dimension of the buckling (few 10th mm). This paper deals with the application of micro beam X-ray diffraction available on synchrotron radiation sources for stress mapping analysis of gold thin film buckling.

  9. Structural characterization of thin film photonic crystals

    SciTech Connect

    Subramania, G.; Biswas, R.; Constant, K.; Sigalas, M. M.; Ho, K. M.

    2001-06-15

    We quantitatively analyze the structure of thin film inverse-opal photonic crystals composed of ordered arrays of air pores in a background of titania. Ordering of the sphere template and introduction of the titania background were performed simultaneously in the thin film photonic crystals. Nondestructive optical measurements of backfilling with high refractive index liquids, angle-resolved reflectivity, and optical spectroscopy were combined with band-structure calculations. The analysis reveals a thin film photonic crystal structure with a very high filling fraction (92{endash}94%) of air and a substantial compression along the c axis ({similar_to}22{endash}25%).

  10. Surface roughness evolution of nanocomposite thin films

    SciTech Connect

    Turkin, A. A.; Pei, Y. T.; Shaha, K. P.; Chen, C. Q.; Vainshtein, D. I.; Hosson, J. Th. M. de

    2009-01-01

    An analysis of dynamic roughening and smoothening mechanisms of thin films grown with pulsed-dc magnetron sputtering is presented. The roughness evolution has been described by a linear stochastic equation, which contains the second- and fourth-order gradient terms. Dynamic smoothening of the growing interface is explained by ballistic effects resulting from impingements of ions to the growing thin film. These ballistic effects are sensitive to the flux and energy of impinging ions. The predictions of the model are compared with experimental data, and it is concluded that the thin film roughness can be further controlled by adjusting waveform, frequency, and width of dc pulses.

  11. Microstructural characterization of a thin film ZrN diffusion barrier in an As-fabricated U-7Mo/Al matrix dispersion fuel plate

    NASA Astrophysics Data System (ADS)

    Keiser, Dennis D.; Perez, Emmanuel; Wiencek, Tom; Leenaers, Ann; Van den Berghe, Sven

    2015-03-01

    The United States High Performance Research Reactor Fuel Development program is developing low enriched uranium fuels for application in research and test reactors. One concept utilizes U-7 wt.% Mo (U-7Mo) fuel particles dispersed in Al matrix, where the fuel particles are coated with a 1 μm-thick ZrN coating. The ZrN serves as a diffusion barrier to eliminate a deleterious reaction that can occur between U-7Mo and Al when a dispersion fuel is irradiated under aggressive reactor conditions. To investigate the final microstructure of a physically-vapor-deposited ZrN coating in a dispersion fuel plate after it was fabricated using a rolling process, characterization samples were taken from a fuel plate that was fabricated at 500 °C using ZrN-coated U-7Mo particles, Al matrix and AA6061 cladding. Scanning electron and transmission electron microscopy analysis were performed. Data from these analyses will be used to support future microstructural examinations of irradiated fuel plates, in terms of understanding the effects of irradiation on the ZrN microstructure, and to determine the role of diffusion barrier microstructure in eliminating fuel/matrix interactions during irradiation. The as-fabricated coating was determined to be cubic-ZrN (cF8) phase. It exhibited a columnar microstructure comprised of nanometer-sized grains and a region of relatively high porosity, mainly near the Al matrix. Small impurity-containing phases were observed at the U-7Mo/ZrN interface, and no interaction zone was observed at the ZrN/Al interface. The bonding between the U-7Mo and ZrN appeared to be mechanical in nature. A relatively high level of oxygen was observed in the ZrN coating, extending from the Al matrix in the ZrN coating in decreasing concentration. The above microstructural characteristics are discussed in terms of what may be most optimal for a diffusion barrier in a dispersion fuel plate application.

  12. Microstructural characterization of a thin film ZrN diffusion barrier in an As-fabricated U–7Mo/Al matrix dispersion fuel plate

    SciTech Connect

    Keiser, Dennis D.; Perez, Emmanuel; Wiencek, Tom; Leenaers, Ann; Van den Berghe, Sven

    2015-03-01

    The United States High Performance Research Reactor Fuel Development program is developing low enriched uranium fuels for application in research and test reactors. One concept utilizes U–7 wt.% Mo (U–7Mo) fuel particles dispersed in Al matrix, where the fuel particles are coated with a 1 μm-thick ZrN coating. The ZrN serves as a diffusion barrier to eliminate a deleterious reaction that can occur between U–7Mo and Al when a dispersion fuel is irradiated under aggressive reactor conditions. To investigate the final microstructure of a physically-vapor-deposited ZrN coating in a dispersion fuel plate after it was fabricated using a rolling process, characterization samples were taken from a fuel plate that was fabricated at 500 °C using ZrN-coated U–7Mo particles, Al matrix and AA6061 cladding. Scanning electron and transmission electron microscopy analysis were performed. Data from these analyses will be used to support future microstructural examinations of irradiated fuel plates, in terms of understanding the effects of irradiation on the ZrN microstructure, and to determine the role of diffusion barrier microstructure in eliminating fuel/matrix interactions during irradiation. The as-fabricated coating was determined to be cubic-ZrN (cF8) phase. It exhibited a columnar microstructure comprised of nanometer-sized grains and a region of relatively high porosity, mainly near the Al matrix. Small impurity-containing phases were observed at the U–7Mo/ZrN interface, and no interaction zone was observed at the ZrN/Al interface. The bonding between the U–7Mo and ZrN appeared to be mechanical in nature. A relatively high level of oxygen was observed in the ZrN coating, extending from the Al matrix in the ZrN coating in decreasing concentration. The above microstructural characteristics are discussed in terms of what may be most optimal for a diffusion barrier in a dispersion fuel plate application.

  13. Strategies to Produce Efficient Electrocatalysts and Improve Electrode Designs for Proton Exchange Membrane Fuel Cells

    NASA Astrophysics Data System (ADS)

    Burk, Jonathan James

    Proton exchange membrane (PEM) fuel cells are electrochemical devices that convert chemical energy to electrical energy. These devices are attractive alternative power sources due to their compact designs, high efficiencies, low emissions, and low noise but have issues with high cost and low durability. In this thesis, electrochemical and thin-film methods were used to understand the limitations of the electrocatalyst in PEM fuel cells and address the issues that limit PEM fuel cell commercialization. The electrochemical deposition of Pt from a novel plating solution was used to control the proximity of fuel cell electrocatalysts. We found that optimized pulse potential deposition parameters produced a large density of nanoparticles with narrow size distribution (1.36 +/- 0.36 nm) on amorphous carbon supports. This resulted in thin catalyst layers (< 8 microm thick) that contained 93 % less Pt that performed similar to and greater than commercial fuel cells. In addition, pulse potential deposition was used to produce functioning PEM fuel cells by using the Nafion membrane as a template to selectively localize Pt in the three-phase reaction zone. The fuel cell performance of these devices had Pt loadings down to 11 microg cm--2 with a maximum power density of 213 mW cm--2. The catalyst layer was redesigned to improve conventional catalyst layer designs that limited MEA durability. A spin cast thin-film method was developed to produce smoother electrode surfaces that lead to lower resistance, isotropic conductivity, and increased contact area to the Nafion membrane. These fuel cells produced higher power and were resistant to electrode delamination. The catalyst activity and stability was improved by redesigning the support structure via constant potential electrolysis of 4-aminomethylpyridine on carbon electrodes. The Pt nanoparticles that were electrodeposited on carbon electrodes functionalized with 4-aminomethylpyridine had improved size and dispersion compared

  14. Polymer electrolyte membrane assembly for fuel cells

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Kindler, Andrew (Inventor); Yavrouian, Andre (Inventor); Halpert, Gerald (Inventor)

    2002-01-01

    An electrolyte membrane for use in a fuel cell can contain sulfonated polyphenylether sulfones. The membrane can contain a first sulfonated polyphenylether sulfone and a second sulfonated polyphenylether sulfone, wherein the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone have equivalent weights greater than about 560, and the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone also have different equivalent weights. Also, a membrane for use in a fuel cell can contain a sulfonated polyphenylether sulfone and an unsulfonated polyphenylether sulfone. Methods for manufacturing a membrane electrode assemblies for use in fuel cells can include roughening a membrane surface. Electrodes and methods for fabricating such electrodes for use in a chemical fuel cell can include sintering an electrode. Such membranes and electrodes can be assembled into chemical fuel cells.

  15. Polymer electrolyte membrane assembly for fuel cells

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Kindler, Andrew (Inventor); Yavrouian, Andre (Inventor); Halpert, Gerald (Inventor)

    2000-01-01

    An electrolyte membrane for use in a fuel cell can contain sulfonated polyphenylether sulfones. The membrane can contain a first sulfonated polyphenylether sulfone and a second sulfonated polyphenylether sulfone, wherein the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone have equivalent weights greater than about 560, and the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone also have different equivalent weights. Also, a membrane for use in a fuel cell can contain a sulfonated polyphenylether sulfone and an unsulfonated polyphenylether sulfone. Methods for manufacturing a membrane electrode assemblies for use in fuel cells can include roughening a membrane surface. Electrodes and methods for fabricating such electrodes for use in a chemical fuel cell can include sintering an electrode. Such membranes and electrodes can be assembled into chemical fuel cells.

  16. Bulk chlorine uptake by polyamide active layers of thin-film composite membranes upon exposure to free chlorine-kinetics, mechanisms, and modeling.

    PubMed

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2014-01-01

    We studied the volume-averaged chlorine (Cl) uptake into the bulk region of the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine. Volume-averaged measurements were obtained using Rutherford backscattering spectrometry with samples prepared at a range of free chlorine concentrations, exposure times, and mixing, rinsing, and pH conditions. Our volume-averaged measurements complement previous studies that have quantified Cl uptake at the active layer surface (top ≈ 7 nm) and advance the mechanistic understanding of Cl uptake by aromatic polyamide active layers. Our results show that surface Cl uptake is representative of and underestimates volume-averaged Cl uptake under acidic conditions and alkaline conditions, respectively. Our results also support that (i) under acidic conditions, N-chlorination followed by Orton rearrangement is the dominant Cl uptake mechanism with N-chlorination as the rate-limiting step; (ii) under alkaline conditions, N-chlorination and dechlorination of N-chlorinated amide links by hydroxyl ion are the two dominant processes; and (iii) under neutral pH conditions, the rates of N-chlorination and Orton rearrangement are comparable. We propose a kinetic model that satisfactorily describes Cl uptake under acidic and alkaline conditions, with the largest discrepancies between model and experiment occurring under alkaline conditions at relatively high chlorine exposures.

  17. Bulk chlorine uptake by polyamide active layers of thin-film composite membranes upon exposure to free chlorine-kinetics, mechanisms, and modeling.

    PubMed

    Powell, Joshua; Luh, Jeanne; Coronell, Orlando

    2014-01-01

    We studied the volume-averaged chlorine (Cl) uptake into the bulk region of the aromatic polyamide active layer of a reverse osmosis membrane upon exposure to free chlorine. Volume-averaged measurements were obtained using Rutherford backscattering spectrometry with samples prepared at a range of free chlorine concentrations, exposure times, and mixing, rinsing, and pH conditions. Our volume-averaged measurements complement previous studies that have quantified Cl uptake at the active layer surface (top ≈ 7 nm) and advance the mechanistic understanding of Cl uptake by aromatic polyamide active layers. Our results show that surface Cl uptake is representative of and underestimates volume-averaged Cl uptake under acidic conditions and alkaline conditions, respectively. Our results also support that (i) under acidic conditions, N-chlorination followed by Orton rearrangement is the dominant Cl uptake mechanism with N-chlorination as the rate-limiting step; (ii) under alkaline conditions, N-chlorination and dechlorination of N-chlorinated amide links by hydroxyl ion are the two dominant processes; and (iii) under neutral pH conditions, the rates of N-chlorination and Orton rearrangement are comparable. We propose a kinetic model that satisfactorily describes Cl uptake under acidic and alkaline conditions, with the largest discrepancies between model and experiment occurring under alkaline conditions at relatively high chlorine exposures. PMID:24506252

  18. Thin film battery/fuel cell power generating system. Final report of the continuation contract (Tasks 1-4), April 1, 1978-March 31, 1980

    SciTech Connect

    Not Available

    1980-06-30

    Research on the design, development, and testing of a high-temperature solid electrolyte (HTSOE) fuel cell is described in detail. Task 1 involves the development and refinement of fabrication processes for the porous support tube, fuel electrode, solid electrolyte, air electrode, and interconnection. Task 2 includes the life testing of cell components and the stack; task 3 involves the stack performance evaluation; task 4 includes demonstrating the reproducibility of 10 watt stacks. A cost, design and benefit study to evaluate the nature and worth of an industrial cogeneration application of the HTSOE fuel cell is underway. Here, promisng applications are now being considered, from which a single application has been selected as a basis for the study - an integrated aluminum production facility. (WHK)

  19. Diamond/AlN Thin Films for Optical Applications

    SciTech Connect

    Knoebber, F.; Bludau, O.; Williams, O. A.; Sah, R. E.; Kirste, L.; Baeumler, M.; Nebel, C. E.; Ambacher, O.; Cimalla, V.; Lebedev, V.; Leopold, S.; Paetz, D.

    2010-11-01

    In this work we report on membranes made of nanocrystalline diamond (NCD) and AlN for the use in tunable micro-optics. For the growth of the AlN and NCD thin films, magnetron sputtering and chemical vapor deposition techniques have been used, respectively. A chemical-mechanical polishing process of NCD layers has been introduced, which is crucial for the growth of c-oriented, fiber textured AlN films. AlN layers deposited on as grown and polished nanocrystalline diamond along with free standing membranes have been compared by studying microstructure, surface morphology, piezoelectrical response as well as optical properties.

  20. Permanent laser conditioning of thin film optical materials

    DOEpatents

    Wolfe, C.R.; Kozlowski, M.R.; Campbell, J.H.; Staggs, M.; Rainer, F.

    1995-12-05

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold. 9 figs.

  1. Permanent laser conditioning of thin film optical materials

    DOEpatents

    Wolfe, C. Robert; Kozlowski, Mark R.; Campbell, John H.; Staggs, Michael; Rainer, Frank

    1995-01-01

    The invention comprises a method for producing optical thin films with a high laser damage threshold and the resulting thin films. The laser damage threshold of the thin films is permanently increased by irradiating the thin films with a fluence below an unconditioned laser damage threshold.

  2. Thin films for geothermal sensing: Final report

    SciTech Connect

    Not Available

    1987-09-01

    The report discusses progress in three components of the geothermal measurement problem: (1) developing appropriate chemically sensitive thin films; (2) discovering suitably rugged and effective encapsulation schemes; and (3) conducting high temperature, in-situ electrochemical measurements. (ACR)

  3. Magnetostrictive thin films for microwave spintronics

    PubMed Central

    Parkes, D. E.; Shelford, L. R.; Wadley, P.; Holý, V.; Wang, M.; Hindmarch, A. T.; van der Laan, G.; Campion, R. P.; Edmonds, K. W.; Cavill, S. A.; Rushforth, A. W.

    2013-01-01

    Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. Such devices require thin ferromagnetic films with large magnetostriction and narrow microwave resonance linewidths. Both properties are often degraded, compared to bulk materials, due to structural imperfections and interface effects in the thin films. We report the development of epitaxial thin films of Galfenol (Fe81Ga19) with magnetostriction as large as the best reported values for bulk material. This allows the magnetic anisotropy and microwave resonant frequency to be tuned by voltage-induced strain, with a larger magnetoelectric response and a narrower linewidth than any previously reported Galfenol thin films. The combination of these properties make epitaxial thin films excellent candidates for developing tunable devices for magnetic information storage, processing and microwave communications. PMID:23860685

  4. Magnetostrictive thin films for microwave spintronics.

    PubMed

    Parkes, D E; Shelford, L R; Wadley, P; Holý, V; Wang, M; Hindmarch, A T; van der Laan, G; Campion, R P; Edmonds, K W; Cavill, S A; Rushforth, A W

    2013-01-01

    Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. Such devices require thin ferromagnetic films with large magnetostriction and narrow microwave resonance linewidths. Both properties are often degraded, compared to bulk materials, due to structural imperfections and interface effects in the thin films. We report the development of epitaxial thin films of Galfenol (Fe81Ga19) with magnetostriction as large as the best reported values for bulk material. This allows the magnetic anisotropy and microwave resonant frequency to be tuned by voltage-induced strain, with a larger magnetoelectric response and a narrower linewidth than any previously reported Galfenol thin films. The combination of these properties make epitaxial thin films excellent candidates for developing tunable devices for magnetic information storage, processing and microwave communications.

  5. Thermally tunable ferroelectric thin film photonic crystals.

    SciTech Connect

    Lin, P. T.; Wessels, B. W.; Imre, A.; Ocola, L. E.; Northwestern Univ.

    2008-01-01

    Thermally tunable PhCs are fabricated from ferroelectric thin films. Photonic band structure and temperature dependent diffraction are calculated by FDTD. 50% intensity modulation is demonstrated experimentally. This device has potential in active ultra-compact optical circuits.

  6. Thin film production method and apparatus

    DOEpatents

    Loutfy, Raouf O.; Moravsky, Alexander P.; Hassen, Charles N.

    2010-08-10

    A method for forming a thin film material which comprises depositing solid particles from a flowing suspension or aerosol onto a filter and next adhering the solid particles to a second substrate using an adhesive.

  7. Thin film solar cell module

    SciTech Connect

    Gay, R.R.

    1987-01-20

    A thin film solar cell module is described comprising a first solar cell panel containing an array of solar cells consisting of a TFS semiconductor sandwiched between a transparent conductive zinc oxide layer and a transparent conductive layer selected from the group consisting of tin oxide, indium tin oxide, and zinc oxide deposited upon a transparent superstrate, and a second solar cell panel containing an array of solar cells consisting of a CIS semiconductor layer sandwiched between a zinc oxide semiconductor layer and a conductive metal layer deposited upon an insulating substrate. The zinc oxide semiconductor layer contains a first relatively thin layer of high resistivity zinc oxide adjacent the CIS semiconductor and a second relatively thick layer of low resistivity zinc oxide overlying the high resistivity zinc oxide layer. The transparent conductive zinc oxide layer of the first panel faces the low resistivity zinc oxide layer of the second panel, the first and second panels being positioned optically in series and separated by a transparent insulating layer.

  8. VUV thin films, chapter 7

    NASA Technical Reports Server (NTRS)

    Zukic, Muamer; Torr, Douglas G.

    1993-01-01

    The application of thin film technology to the vacuum ultraviolet (VUV) wavelength region from 120 nm to 230 nm has not been fully exploited in the past because of absorption effects which complicate the accurate determination of the optical functions of dielectric materials. The problem therefore reduces to that of determining the real and imaginary parts of a complex optical function, namely the frequency dependent refractive index n and extinction coefficient k. We discuss techniques for the inverse retrieval of n and k for dielectric materials at VUV wavelengths from measurements of their reflectance and transmittance. Suitable substrate and film materials are identified for application in the VUV. Such applications include coatings for the fabrication of narrow and broadband filters and beamsplitters. The availability of such devices open the VUV regime to high resolution photometry, interferometry and polarimetry both for space based and laboratory applications. This chapter deals with the optics of absorbing multilayers, the determination of the optical functions for several useful materials, and the design of VUV multilayer stacks as applied to the design of narrow and broadband reflection and transmission filters and beamsplitters. Experimental techniques are discussed briefly, and several examples of the optical functions derived for selected materials are presented.

  9. Flush Mounting Of Thin-Film Sensors

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1992-01-01

    Technique developed for mounting thin-film sensors flush with surfaces like aerodynamic surfaces of aircraft, which often have compound curvatures. Sensor mounted in recess by use of vacuum pad and materials selected for specific application. Technique involves use of materials tailored to thermal properties of substrate in which sensor mounted. Together with customized materials, enables flush mounting of thin-film sensors in most situations in which recesses for sensors provided. Useful in both aircraft and automotive industries.

  10. Thin-film microelectronic wearable body sensors.

    PubMed

    Neuman, Michael R

    2015-01-01

    This review of various applications of well-established thin-film processing techniques to wearable body sensors gives examples of work done in the author's laboratory over many years. Sensors for the vital signs of body temperature, electrocardiogram, heart rate, breathing pattern and breathing rate are presented along with other applications. Thin-film based sensors have the advantage of small size, high surface area to mass ratio, flexibility, capability for batch production, and compatibility with other microelectronic technologies.

  11. Epitaxial thin film growth in outer space

    NASA Technical Reports Server (NTRS)

    Ignatiev, Alex; Chu, C. W.

    1988-01-01

    A new concept for materials processing in space exploits the ultravacuum component of space for thin-film epitaxial growth. The unique LEO space environment is expected to yield 10-ftorr or better pressures, semiinfinite pumping speeds, and large ultravacuum volume (about 100 cu m) without walls. These space ultravacuum properties promise major improvement in the quality, unique nature, and throughput of epitaxially grown materials, including semiconductors, magnetic materials, and thin-film high-temperature superconductors.

  12. Thin-film reliability and engineering overview

    NASA Technical Reports Server (NTRS)

    Ross, R. G., Jr.

    1984-01-01

    The reliability and engineering technology base required for thin film solar energy conversions modules is discussed. The emphasis is on the integration of amorphous silicon cells into power modules. The effort is being coordinated with SERI's thin film cell research activities as part of DOE's Amorphous Silicon Program. Program concentration is on temperature humidity reliability research, glass breaking strength research, point defect system analysis, hot spot heating assessment, and electrical measurements technology.

  13. Thin film composition with biological substance and method of making

    DOEpatents

    Campbell, Allison A.; Song, Lin

    1999-01-01

    The invention provides a thin-film composition comprising an underlying substrate of a first material including a plurality of attachment sites; a plurality of functional groups chemically attached to the attachment sites of the underlying substrate; and a thin film of a second material deposited onto the attachment sites of the underlying substrate, and a biologically active substance deposited with the thin-film. Preferably the functional groups are attached to a self assembling monolayer attached to the underlying substrate. Preferred functional groups attached to the underlying substrate are chosen from the group consisting of carboxylates, sulfonates, phosphates, optionally substituted, linear or cyclo, alkyl, alkene, alkyne, aryl, alkylaryl, amine, hydroxyl, thiol, silyl, phosphoryl, cyano, metallocenyl, carbonyl, and polyphosphate. Preferred materials for the underlying substrate are selected from the group consisting of a metal, a metal alloy, a plastic, a polymer, a proteic film, a membrane, a glass or a ceramic. The second material is selected from the group consisting of inorganic crystalline structures, inorganic amorphus structures, organic crystalline structures, and organic amorphus structures. Preferred second materials are phosphates, especially calcium phosphates and most particularly calcium apatite. The biologically active molecule is a protein, peptide, DNA segment, RNA segment, nucleotide, polynucleotide, nucleoside, antibiotic, antimicrobal, radioisotope, chelated radioisotope, chelated metal, metal salt, anti-inflamatory, steriod, nonsteriod anti-inflammatory, analgesic, antihistamine, receptor binding agent, or chemotherapeutic agent, or other biologically active material. Preferably the biologically active molecule is an osteogenic factor the compositions listed above.

  14. Fuel cell and membrane therefore

    DOEpatents

    Aindow, Tai-Tsui

    2016-08-09

    A fuel cell includes first and second flow field plates, and an anode electrode and a cathode electrode between the flow field plates. A polymer electrolyte membrane (PEM) is arranged between the electrodes. At least one of the flow field plates influences, at least in part, an in-plane anisotropic physical condition of the PEM that varies in magnitude between a high value direction and a low value direction. The PEM has an in-plane physical property that varies in magnitude between a high value direction and a low value direction. The PEM is oriented with its high value direction substantially aligned with the high value direction of the flow field plate.

  15. Printable CIGS thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fan, Xiaojuan

    2013-03-01

    Among the various thin film solar cells in the market, CuInGaSe thin film solar cells have been considered as the most promising alternatives to crystalline silicon solar cells because of their high photo-electricity conversion efficiency, reliability, and stability. However, many fabrication methods of CIGS thin film are based on vacuum processes such as evaporation and sputtering techniques which are not cost efficient. This work develops a solution method using paste or ink liquid spin-coated on glass that would be competitive to conventional ways in terms of cost effective, non-vacuum needed, and quick processing. A mixture precursor was prepared by dissolving appropriate amounts of composition chemicals. After the mixture solution was cooled, a viscous paste was prepared and ready for spin-coating process. A slight bluish CIG thin film on substrate was then put in a tube furnace with evaporation of metal Se followed by depositing CdS layer and ZnO nanoparticle thin film coating to complete a solar cell fabrication. Structure, absorption spectrum, and photo-electricity conversion efficiency for the as-grown CIGS thin film solar cell are under study.

  16. Research on Advanced Thin Film Batteries

    SciTech Connect

    Goldner, Ronald B.

    2003-11-24

    During the past 7 years, the Tufts group has been carrying out research on advanced thin film batteries composed of a thin film LiCo02 cathode (positive electrode), a thin film LiPON (lithium phosphorous oxynitride) solid electrolyte, and a thin film graphitic carbon anode (negative electrode), under grant DE FG02-95ER14578. Prior to 1997, the research had been using an rfsputter deposition process for LiCoOi and LiPON and an electron beam evaporation or a controlled anode arc evaporation method for depositing the carbon layer. The pre-1997 work led to the deposition of a single layer cell that was successfully cycled for more than 400 times [1,2] and the research also led to the deposition of a monolithic double-cell 7 volt battery that was cycled for more than 15 times [3]. Since 1997, the research has been concerned primarily with developing a research-worthy and, possibly, a production-worthy, thin film deposition process, termed IBAD (ion beam assisted deposition) for depositing each ofthe electrodes and the electrolyte of a completely inorganic solid thin film battery. The main focus has been on depositing three materials - graphitic carbon as the negative electrode (anode), lithium cobalt oxide (nominally LiCoCb) as the positive electrode (cathode), and lithium phosphorus oxynitride (LiPON) as the electrolyte. Since 1998, carbon, LiCoOa, and LiPON films have been deposited using the IBAD process with the following results.

  17. Carbon Nanotube Thin-Film Antennas.

    PubMed

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of <10 ohm/sq is needed to achieve a 10 dB return loss in the unbalanced antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed. PMID:27454334

  18. Carbon Nanotube Thin-Film Antennas.

    PubMed

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of <10 ohm/sq is needed to achieve a 10 dB return loss in the unbalanced antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

  19. Printable CIGS thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fan, Xiaojuan

    2014-03-01

    Among the various thin film solar cells in the market, CuInGaSe thin film cells have been considered as the most promising alternatives to silicon solar cells because of their high photo-electricity efficiency, reliability, and stability. However, many fabrication of CIGS thin film are based on vacuum processes such as evaporation sputtering techniques which are not cost efficient. This work develops a method using paste or ink liquid spin-coated on glass that would be to conventional ways in terms of cost effective, non-vacuum needed, quick processing. A mixture precursor was prepared by dissolving appropriate amounts of chemicals. After the mixture solution was cooled, a viscous paste prepared and ready for spin-coating process. A slight bluish CIG thin film substrate was then put in a tube furnace with evaporation of metal Se by depositing CdS layer and ZnO nanoparticle thin film coating to a solar cell fabrication. Structure, absorption spectrum, and photo-conversion efficiency for the as-grown CIGS thin film solar cell under study.

  20. YSZ thin films with minimized grain boundary resistivity.

    PubMed

    Mills, Edmund M; Kleine-Boymann, Matthias; Janek, Juergen; Yang, Hao; Browning, Nigel D; Takamura, Yayoi; Kim, Sangtae

    2016-04-21

    In recent years, interface engineering of solid electrolytes has been explored to increase their ionic conductivity and improve the performance of solid oxide fuel cells and other electrochemical power sources. It has been observed that the ionic conductivity of epitaxially grown thin films of some electrolytes is dramatically enhanced, which is often attributed to effects (e.g. strain-induced mobility changes) at the heterophase boundary with the substrate. Still largely unexplored is the possibility of manipulation of grain boundary resistivity in polycrystalline solid electrolyte films, clearly a limiting factor in their ionic conductivity. Here we report that the ionic conductivity of yttria stabilized zirconia thin films with nano-columnar grains grown on a MgO substrate nearly reaches that of the corresponding single crystal when the thickness of the films becomes less than roughly 8 nm (smaller by a factor of three at 500 °C). Using impedance spectroscopy, the grain boundary resistivity was probed as a function of film thickness. The resistivity of the grain boundaries near the film-substrate interface and film surface (within 4 nm of each) was almost entirely eliminated. This minimization of grain boundary resistivity is attributed to Mg(2+) diffusion from the MgO substrate into the YSZ grain boundaries, which is supported by time of flight secondary ion mass spectroscopy measurements. We suggest grain boundary "design" as an attractive method to obtain highly conductive solid electrolyte thin films.

  1. ADVANCED HYDROGEN TRANSPORT MEMBRANES FOR VISION 21 FOSSIL FUEL PLANTS

    SciTech Connect

    Carl R. Evenson; Anthony F. Sammells; Richard Mackay; Scott R. Morrison; Sara L. Rolfe; Richard Blair; U. Balachandran; Richard N. Kleiner; James E. Stephan; Frank E. Anderson; Chandra Ratnasamy; Jon P. Wagner; Clive Brereton; Warren Wolfs

    2004-04-26

    During this quarter, work was focused on testing layered composite membranes under varying feed stream flow rates at high pressure. By optimizing conditions, H{sub 2} permeation rates in excess of 400 mL {center_dot} min{sup -1} {center_dot} cm{sup -2} at 440 C were measured. Membrane stability was characterized by repeated thermal and pressure cycling. The effect of cermet grain size on permeation was determined. Finally, progress is summarized on thin film cermet fabrication, catalyst development, and H{sub 2} separation unit scale up.

  2. Conditioning effects on La1-xSrxMnO3-Yttria stabilized Zirconia electrodes for thin-film solid oxide fuel cells

    SciTech Connect

    Lee, You-Kee; Kim, Jung-Yeul; Lee, Young-Ki; Kim, Insoo; Moon, Hee-Soo; Park, Jong-Wan; Jacobson, Craig P.; Visco, Steven J.

    2002-12-06

    Composite cathodes of 50/50 vol percent LSM-YSZ (La1-xSrxMnO3-yttria stabilized zirconia) were deposited onto dense YSZ electrolytes by a colloidal deposition technique. The cathode characteristics were then examined by scanning electron microscopy (SEM) and studied by an impedance spectroscopy (IS). Conditioning effects of the LSM-YSZ cathodes were seen, and remedies for these effects were proposed for improving the performance of a solid oxide fuel cell (SOFC). LSM surface contamination and modification, cathode bonding to the YSZ electrolyte, changing Pt electrode and bonding paste, and curvature of sintered YSZ electrolytes led to some changes in microstructure and variability in cell performances.

  3. Proton Exchange Membranes for Fuel Cells

    SciTech Connect

    Devanathan, Ramaswami

    2010-11-01

    Proton exchange membrane, also known as polymer electrolyte membrane, fuel cells (PEMFCs) offer the promise of efficient conversion of chemical energy of fuel, such as hydrogen or methanol, into electricity with minimal pollution. Their widespread use to power zero-emission automobiles as part of a hydrogen economy can contribute to enhanced energy security and reduction in greenhouse gas emissions. However, the commercial viability of PEMFC technology is hindered by high cost associated with the membrane electrode assembly (MEA) and poor membrane durability under prolonged operation at elevated temperature. Membranes for automotive fuel cell applications need to perform well over a period comparable to the life of an automotive engine and under heavy load cycling including start-stop cycling under sub-freezing conditions. The combination of elevated temperature, changes in humidity levels, physical stresses and harsh chemical environment contribute to membrane degradation. Perfluorinated sulfonic acid (PFSA)-based membranes, such as Nafion®, have been the mainstay of PEMFC technology. Their limitations, in terms of cost and poor conductivity at low hydration, have led to continuing research into membranes that have good proton conductivity at elevated temperatures above 120 °C and under low humidity conditions. Such membranes have the potential to avoid catalyst poisoning, simplify fuel cell design and reduce the cost of fuel cells. Hydrocarbon-based membranes are being developed as alternatives to PFSA membranes, but concerns about chemical and mechanical stability and durability remain. Novel anhydrous membranes based on polymer gels infused with protic ionic liquids have also been recently proposed, but considerable fundamental research is needed to understand proton transport in novel membranes and evaluate durability under fuel cell operating conditions. In order to advance this promising technology, it is essential to rationally design the next generation

  4. Micromotors using magnetostrictive thin films

    NASA Astrophysics Data System (ADS)

    Claeyssen, Frank; Le Letty, Ronan; Barillot, Francois; Betz, Jochen; MacKay, Ken; Givord, Dominique; Bouchilloux, Philippe

    1998-07-01

    This study deals with a micromotor based on the use of magnetostrictive thin films. This motor belongs to the category of the Standing Wave Ultrasonic Motors. The active part of the motor is the rotor, which is a 100 micrometers thick ring vibrating in a flexural mode. Teeth (300 micrometers high) are placed on special positions of the rotor and produce an oblique motion which can induce the relative motion of any object in contact with them. The magnetic excitation field is radial and uses the transverse coupling of the 4 micrometers thick magnetostrictive film. The film, deposited by sputtering on the ring, consists of layers of different rare-earth/iron alloys and was developed during a European Brite-Euram project. The finite element technique was used in order to design a prototype of the motor and to optimize the active rotor and the energizer coil. The prototype we built delivered a speed of 30 turns per minute with a torque of 2 (mu) N.m (without prestress applied on the rotor). Our experimental results show that the performance of this motor could easily be increased by a factor of 5. The main advantage of this motor is the fact that it is remotely powered and controlled. The excitation coil, which provides both power and control, can be placed away from the active rotor. Moreover, the rotor is completely wireless and is not connected to its support or to any other part. It is interesting to note that it would not be possible to build this type of motor using piezoelectric technology. Medical applications of magnetostrictive micromotors could be found for internal microdistributors of medication (the coil staying outside the body). Other applications include remote control micropositioning, micropositioning of optical components, and for the actuation of systems such as valves, electrical switches, and relays.

  5. Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films

    DOEpatents

    Brinker, Charles Jeffrey; Prakash, Sai Sivasankaran

    1999-01-01

    A method for preparing aerogel thin films by an ambient-pressure, continuous process. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

  6. Thin film porous membranes for catalytic sensors

    SciTech Connect

    Hughes, R.C.; Boyle, T.J.; Gardner, T.J.

    1997-06-01

    This paper reports on new and surprising experimental data for catalytic film gas sensing resistors coated with nanoporous sol-gel films to impart selectivity and durability to the sensor structure. This work is the result of attempts to build selectivity and reactivity to the surface of a sensor by modifying it with a series of sol-gel layers. The initial sol-gel SiO{sub 2} layer applied to the sensor surprisingly showed enhanced O{sub 2} interaction with H{sub 2} and reduced susceptibility to poisons such as H{sub 2}S.

  7. Fuel cell ion-exchange membrane investigation

    NASA Technical Reports Server (NTRS)

    Toy, M. S.

    1972-01-01

    The present deficiencies in the fluorocarbon sulfonic acid membrane used as the solid polymer electrolyte in the H2/O2 fuel cell are studied. Considered are: Adhesives selection, elastomeric formulations, scavenger exploration, and membrane characterization. The significant data are interpreted and recommendations are given for both short and long range further investigations in two of the four major areas: membrane adhesives and membrane stabilization.

  8. Fuel cell membranes and crossover prevention

    DOEpatents

    Masel, Richard I.; York, Cynthia A.; Waszczuk, Piotr; Wieckowski, Andrzej

    2009-08-04

    A membrane electrode assembly for use with a direct organic fuel cell containing a formic acid fuel includes a solid polymer electrolyte having first and second surfaces, an anode on the first surface and a cathode on the second surface and electrically linked to the anode. The solid polymer electrolyte has a thickness t:.gtoreq..times..times..times..times. ##EQU00001## where C.sub.f is the formic acid fuel concentration over the anode, D.sub.f is the effective diffusivity of the fuel in the solid polymer electrolyte, K.sub.f is the equilibrium constant for partition coefficient for the fuel into the solid polymer electrolyte membrane, I is Faraday's constant n.sub.f is the number of electrons released when 1 molecule of the fuel is oxidized, and j.sub.f.sup.c is an empirically determined crossover rate of fuel above which the fuel cell does not operate.

  9. Proton-conducting Micro-solid Oxide Fuel Cells with Improved Cathode Reactions by a Nanoscale Thin Film Gadolinium-doped Ceria Interlayer

    PubMed Central

    Li, Yong; Wang, Shijie; Su, Pei-Chen

    2016-01-01

    An 8 nm-thick gadolinium-doped ceria (GDC) layer was inserted as a cathodic interlayer between the nanoscale proton-conducting yttrium-doped barium zirconate (BZY) electrolyte and the porous platinum cathode of a micro-solid oxide fuel cell (μ-SOFC), which has effectively improved the cathode reaction kinetics and rendered high cell power density. The addition of the GDC interlayer significantly reduced the cathodic activation loss and increased the peak power density of the μ-SOFC by 33% at 400 °C. The peak power density reached 445 mW/cm2 at 425 °C, which is the highest among the reported μ-SOFCs using proton-conducting electrolytes. The impressive performance was attributed to the mixed protonic and oxygen ionic conducting properties of the nano-granular GDC, and also to the high densities of grain boundaries and lattice defects in GDC interlayer that favored the oxygen incorporation and transportation during the oxygen reduction reaction (ORR) and the water evolution reaction at cathode. PMID:26928192

  10. Proton-conducting Micro-solid Oxide Fuel Cells with Improved Cathode Reactions by a Nanoscale Thin Film Gadolinium-doped Ceria Interlayer

    NASA Astrophysics Data System (ADS)

    Li, Yong; Wang, Shijie; Su, Pei-Chen

    2016-02-01

    An 8 nm-thick gadolinium-doped ceria (GDC) layer was inserted as a cathodic interlayer between the nanoscale proton-conducting yttrium-doped barium zirconate (BZY) electrolyte and the porous platinum cathode of a micro-solid oxide fuel cell (μ-SOFC), which has effectively improved the cathode reaction kinetics and rendered high cell power density. The addition of the GDC interlayer significantly reduced the cathodic activation loss and increased the peak power density of the μ-SOFC by 33% at 400 °C. The peak power density reached 445 mW/cm2 at 425 °C, which is the highest among the reported μ-SOFCs using proton-conducting electrolytes. The impressive performance was attributed to the mixed protonic and oxygen ionic conducting properties of the nano-granular GDC, and also to the high densities of grain boundaries and lattice defects in GDC interlayer that favored the oxygen incorporation and transportation during the oxygen reduction reaction (ORR) and the water evolution reaction at cathode.

  11. Thin film absorber for a solar collector

    DOEpatents

    Wilhelm, William G.

    1985-01-01

    This invention pertains to energy absorbers for solar collectors, and more particularly to high performance thin film absorbers. The solar collectors comprising the absorber of this invention overcome several problems seen in current systems, such as excessive hardware, high cost and unreliability. In the preferred form, the apparatus features a substantially rigid planar frame with a thin film window bonded to one planar side of the frame. An absorber in accordance with the present invention is comprised of two thin film layers that are sealed perimetrically. In a preferred embodiment, thin film layers are formed from a metal/plastic laminate. The layers define a fluid-tight planar envelope of large surface area to volume through which a heat transfer fluid flows. The absorber is bonded to the other planar side of the frame. The thin film construction of the absorber assures substantially full envelope wetting and thus good efficiency. The window and absorber films stress the frame adding to the overall strength of the collector.

  12. Ferromagnetic properties of fcc Gd thin films

    SciTech Connect

    Bertelli, T. P. Passamani, E. C.; Larica, C.; Nascimento, V. P.; Takeuchi, A. Y.

    2015-05-28

    Magnetic properties of sputtered Gd thin films grown on Si (100) substrates kept at two different temperatures were investigated using X-ray diffraction, ac magnetic susceptibility, and dc magnetization measurements. The obtained Gd thin films have a mixture of hcp and fcc structures, but with their fractions depending on the substrate temperature T{sub S} and film thickness x. Gd fcc samples were obtained when T{sub S} = 763 K and x = 10 nm, while the hcp structure was stabilized for lower T{sub S} (300 K) and thicker film (20 nm). The fcc structure is formed on the Ta buffer layer, while the hcp phase grows on the fcc Gd layer as a consequence of the lattice relaxation process. Spin reorientation phenomenon, commonly found in bulk Gd species, was also observed in the hcp Gd thin film. This phenomenon is assumed to cause the magnetization anomalous increase observed below 50 K in stressed Gd films. Magnetic properties of fcc Gd thin films are: Curie temperature above 300 K, saturation magnetization value of about 175 emu/cm{sup 3}, and coercive field of about 100 Oe at 300 K; features that allow us to classify Gd thin films, with fcc structure, as a soft ferromagnetic material.

  13. Thin film dielectric composite materials

    DOEpatents

    Jia, Quanxi; Gibbons, Brady J.; Findikoglu, Alp T.; Park, Bae Ho

    2002-01-01

    A dielectric composite material comprising at least two crystal phases of different components with TiO.sub.2 as a first component and a material selected from the group consisting of Ba.sub.1-x Sr.sub.x TiO.sub.3 where x is from 0.3 to 0.7, Pb.sub.1-x Ca.sub.x TiO.sub.3 where x is from 0.4 to 0.7, Sr.sub.1-x Pb.sub.x TiO.sub.3 where x is from 0.2 to 0.4, Ba.sub.1-x Cd.sub.x TiO.sub.3 where x is from 0.02 to 0.1, BaTi.sub.1-x Zr.sub.x O.sub.3 where x is from 0.2 to 0.3, BaTi.sub.1-x Sn.sub.x O.sub.3 where x is from 0.15 to 0.3, BaTi.sub.1-x Hf.sub.x O.sub.3 where x is from 0.24 to 0.3, Pb.sub.1-1.3x La.sub.x TiO.sub.3+0.2x where x is from 0.23 to 0.3, (BaTiO.sub.3).sub.x (PbFeo.sub.0.5 Nb.sub.0.5 O.sub.3).sub.1-x where x is from 0.75 to 0.9, (PbTiO.sub.3).sub.- (PbCo.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.1 to 0.45, (PbTiO.sub.3).sub.x (PbMg.sub.0.5 W.sub.0.5 O.sub.3).sub.1-x where x is from 0.2 to 0.4, and (PbTiO.sub.3).sub.x (PbFe.sub.0.5 Ta.sub.0.5 O.sub.3).sub.1-x where x is from 0 to 0.2, as the second component is described. The dielectric composite material can be formed as a thin film upon suitable substrates.

  14. Method for synthesizing thin film electrodes

    DOEpatents

    Boyle, Timothy J.

    2007-03-13

    A method for making a thin-film electrode, either an anode or a cathode, by preparing a precursor solution using an alkoxide reactant, depositing multiple thin film layers with each layer approximately 500 1000 .ANG. in thickness, and heating the layers to above 600.degree. C. to achieve a material with electrochemical properties suitable for use in a thin film battery. The preparation of the anode precursor solution uses Sn(OCH.sub.2C(CH.sub.3).sub.3).sub.2 dissolved in a solvent in the presence of HO.sub.2CCH.sub.3 and the cathode precursor solution is formed by dissolving a mixture of (Li(OCH.sub.2C(CH.sub.3).sub.3)).sub.8 and Co(O.sub.2CCH.sub.3).H.sub.2O in at least one polar solvent.

  15. Thin Film Transistors On Plastic Substrates

    DOEpatents

    Carey, Paul G.; Smith, Patrick M.; Sigmon, Thomas W.; Aceves, Randy C.

    2004-01-20

    A process for formation of thin film transistors (TFTs) on plastic substrates replaces standard thin film transistor fabrication techniques, and uses sufficiently lower processing temperatures so that inexpensive plastic substrates may be used in place of standard glass, quartz, and silicon wafer-based substrates. The silicon based thin film transistor produced by the process includes a low temperature substrate incapable of withstanding sustained processing temperatures greater than about 250.degree. C., an insulating layer on the substrate, a layer of silicon on the insulating layer having sections of doped silicon, undoped silicon, and poly-silicon, a gate dielectric layer on the layer of silicon, a layer of gate metal on the dielectric layer, a layer of oxide on sections of the layer of silicon and the layer of gate metal, and metal contacts on sections of the layer of silicon and layer of gate metal defining source, gate, and drain contacts, and interconnects.

  16. Thin film ferroelectric electro-optic memory

    NASA Technical Reports Server (NTRS)

    Thakoor, Sarita (Inventor); Thakoor, Anilkumar P. (Inventor)

    1993-01-01

    An electrically programmable, optically readable data or memory cell is configured from a thin film of ferroelectric material, such as PZT, sandwiched between a transparent top electrode and a bottom electrode. The output photoresponse, which may be a photocurrent or photo-emf, is a function of the product of the remanent polarization from a previously applied polarization voltage and the incident light intensity. The cell is useful for analog and digital data storage as well as opto-electric computing. The optical read operation is non-destructive of the remanent polarization. The cell provides a method for computing the product of stored data and incident optical data by applying an electrical signal to store data by polarizing the thin film ferroelectric material, and then applying an intensity modulated optical signal incident onto the thin film material to generate a photoresponse therein related to the product of the electrical and optical signals.

  17. Magnetoelectric thin film composites with interdigital electrodes

    NASA Astrophysics Data System (ADS)

    Piorra, A.; Jahns, R.; Teliban, I.; Gugat, J. L.; Gerken, M.; Knöchel, R.; Quandt, E.

    2013-07-01

    Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.

  18. Mesoscale morphologies in polymer thin films.

    SciTech Connect

    Ramanathan, M.; Darling, S. B.

    2011-06-01

    In the midst of an exciting era of polymer nanoscience, where the development of materials and understanding of properties at the nanoscale remain a major R&D endeavor, there are several exciting phenomena that have been reported at the mesoscale (approximately an order of magnitude larger than the nanoscale). In this review article, we focus on mesoscale morphologies in polymer thin films from the viewpoint of origination of structure formation, structure development and the interaction forces that govern these morphologies. Mesoscale morphologies, including dendrites, holes, spherulites, fractals and honeycomb structures have been observed in thin films of homopolymer, copolymer, blends and composites. Following a largely phenomenological level of description, we review the kinetic and thermodynamic aspects of mesostructure formation outlining some of the key mechanisms at play. We also discuss various strategies to direct, limit, or inhibit the appearance of mesostructures in polymer thin films as well as an outlook toward potential areas of growth in this field of research.

  19. Tungsten-doped thin film materials

    DOEpatents

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  20. Vibration welding system with thin film sensor

    DOEpatents

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

    2014-03-18

    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  1. AES analysis of barium fluoride thin films

    NASA Astrophysics Data System (ADS)

    Kashin, G. N.; Makhnjuk, V. I.; Rumjantseva, S. M.; Shchekochihin, Ju. M.

    1993-06-01

    AES analysis of thin films of metal fluorides is a difficult problem due to charging and decomposition of such films under electron bombardment. We have developed a simple algorithm for a reliable quantitative AES analysis of metal fluoride thin films (BaF 2 in our work). The relative AES sensitivity factors for barium and fluorine were determined from BaF 2 single-crystal samples. We have investigated the dependence of composition and stability of barium fluoride films on the substrate temperature during film growth. We found that the instability of BaF 2 films grown on GaAs substrates at high temperatures (> 525°C) is due to a loss of fluorine. Our results show that, under the optimal electron exposure conditions, AES can be used for a quantitative analysis of metal fluoride thin films.

  2. Thin film silicon photovoltaic module performance assessment

    NASA Astrophysics Data System (ADS)

    Jennings, Christina

    1987-06-01

    This report evaluates the performance through December, 1986 of 15 commercially-available thin film silicon-hydrogen alloy PV modules manufactured by ARCO Solar, Chronar, ECD/Sovonics, and Solarex. Advances in the technology are indicated by the performance improvements associated with each generation of thin film silicon-hydrogen alloy PV modules introduced to the commercial market. Mounted at a 30 degree tilt facing due south, all of the thin film PV modules under evaluation have experienced decreased efficiency and fill factor on initial sun exposure. Midday efficiency tends to be highest during the summer and lowest during the winter. The seasonal change in midday air mass from 1.0 during the summer to 1.4 during the winter is among the factors that counteract the temperature effects and cause lowered efficiency and fill factor values during the winter.

  3. Microscale damping using thin film active materials

    NASA Astrophysics Data System (ADS)

    Kerrigan, Catherine A.; Ho, Ken K.; Mohanchandra, K. P.; Carman, Gregory P.

    2007-04-01

    This paper focuses on understanding and developing a new approach to dampen MEMS structures using both experiments and analytical techniques. Thin film Nitinol and thin film Terfenol-D are evaluated as a damping solution to the micro scale damping problem. Stress induced twin boundary motion in Nitinol is used to passively dampen potentially damaging vibrations. Magnetic domain wall motion is used to passively dampen vibration in Terfenol-D. The thin films of Nitinol, Nitinol/Silicon laminates and Nitinol/Terfenol-D/Nickel laminates have been produced using a sputter deposition process and damping properties have been evaluated. Dynamic testing shows substantial damping (tan δ) measurable in each case. Nitinol film samples were tested in the Differential Scanning Calorimetry (DSC) to determine phase transformation temperatures. The twin boundary mechanism by which energy absorption occurs is present at all points below the Austenite start temperature (approximately 69°C in our film) and therefore allows damping at cold temperatures where traditional materials fail. Thin film in the NiTi/Si laminate was found to produce substantially higher damping (tan δ = 0.28) due to the change in loading condition. The NiTi/Si laminate sample was tested in bending allowing the twin boundaries to be reset by cyclic tensile and compressive loads. The thin film Terfenol-D in the Nitinol/Terfenol-D/Nickel laminate was shown to produce large damping (tan δ = 0.2). In addition to fabricating and testing, an analytical model of a heterogeneous layered thin film damping material was developed and compared to experimental work.

  4. Insect thin films as solar collectors.

    PubMed

    Heilman, B D; Miaoulis, L N

    1994-10-01

    A numerical method for simulation of microscale radiation effects in insect thin-film structures is described. Accounting for solar beam and diffuse radiation, the model calculates the reflectivity and emissivity of such structures. A case study examines microscale radiation effects in butterfuly wings, and results reveal a new function of these multilayer thin films: thermal regulation. For film thicknesses of the order of 0.10 µm, solar absorption levels vary by as much as 25% with small changes in film thickness; for certain existing structures, absorption levels reach 96%., This is attributed to the spectral distribution of the reflected radiation, which consists of a singular reflectance peak within the solar spectrum.

  5. Emittance Theory for Thin Film Selective Emitter

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Lowe, Roland A.; Good, Brian S.

    1994-01-01

    Thin films of high temperature garnet materials such as yttrium aluminum garnet (YAG) doped with rare earths are currently being investigated as selective emitters. This paper presents a radiative transfer analysis of the thin film emitter. From this analysis the emitter efficiency and power density are calculated. Results based on measured extinction coefficients for erbium-YAG and holmium-YAG are presented. These results indicated that emitter efficiencies of 50 percent and power densities of several watts/sq cm are attainable at moderate temperatures (less than 1750 K).

  6. Thin film photovoltaics -- Strategy of Eurec Agency

    SciTech Connect

    Bloss, W.H.

    1994-12-31

    European activities in the field of thin film photovoltaics are coordinated in a network by Eurec Agency (European Renewable Energy Centres Agency). Main emphasis lies in the development of an appropriate production technology of CIS and CdTe based photovoltaic modules in an industrial scale. These efforts are supported by a research program on relevant materials, structures and processes for thin film photovoltaics. Substantial progress has been achieved during the last years which opens new perspectives for future trends. Joint efforts in research and development based on CIS are coordinated by the network EUROCIS. A screening program on natural minerals with relevance to photovoltaic performance provides the basis for further strategic steps.

  7. Feasibility Study of Thin Film Thermocouple Piles

    NASA Technical Reports Server (NTRS)

    Sisk, R. C.

    2001-01-01

    Historically, thermopile detectors, generators, and refrigerators based on bulk materials have been used to measure temperature, generate power for spacecraft, and cool sensors for scientific investigations. New potential uses of small, low-power, thin film thermopiles are in the area of microelectromechanical systems since power requirements decrease as electrical and mechanical machines shrink in size. In this research activity, thin film thermopile devices are fabricated utilizing radio frequency sputter coating and photoresist lift-off techniques. Electrical characterizations are performed on two designs in order to investigate the feasibility of generating small amounts of power, utilizing any available waste heat as the energy source.

  8. Micro-sensor thin-film anemometer

    NASA Technical Reports Server (NTRS)

    Sheplak, Mark (Inventor); McGinley, Catherine B. (Inventor); Spina, Eric F. (Inventor); Stephens, Ralph M. (Inventor); Hopson, Jr., Purnell (Inventor); Cruz, Vincent B. (Inventor)

    1996-01-01

    A device for measuring turbulence in high-speed flows is provided which includes a micro-sensor thin-film probe. The probe is formed from a single crystal of aluminum oxide having a 14.degree. half-wedge shaped portion. The tip of the half-wedge is rounded and has a thin-film sensor attached along the stagnation line. The bottom surface of the half-wedge is tilted upward to relieve shock induced disturbances created by the curved tip of the half-wedge. The sensor is applied using a microphotolithography technique.

  9. Borocarbide thin films and tunneling measurements.

    SciTech Connect

    Iavarone, M.; Andreone, A.; Cassinese, A.; Dicapual, R.; giannil, L.; Vagliol, R.; DeWilde, Y.; Crabtree, G. W.

    2000-06-15

    The results obtained by their group in thin film fabrication and STM tunneling on superconducting borocarbides YNi{sub 2}B{sub 2}C have been be briefly reviewed. Results concerning the microwave surface impedance and the S/N planar junctions on LuNi{sub 2}B{sub 2}C thin films have been also presented and analyzed. These new data unambiguously confirm the full BCS nature of the superconducting gap in borocarbides and the absence of significant pair-breaking effects in LuNi{sub 2}B{sub 2}C.

  10. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

    Dudney, N. J.; Bates, J. B.; Lubben, D.

    1995-06-01

    Thin film rechargeable lithium batteries using ceramic electrolyte and cathode materials have been fabricated by physical deposition techniques. The lithium phosphorous oxynitride electrolyte has exceptional electrochemical stability and a good lithium conductivity. The lithium insertion reaction of several different intercalation materials, amorphous V{sub 2}O{sub 5}, amorphous LiMn{sub 2}O{sub 4}, and crystalline LiMn{sub 2}O{sub 4} films, have been investigated using the completed cathode/electrolyte/lithium thin film battery.

  11. Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

    SciTech Connect

    Carl R. Evenson; Shane E. Roark

    2006-03-31

    The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative.

  12. Silver Nanoparticle Enhanced Freestanding Thin-Film Silicon Solar Cells

    NASA Astrophysics Data System (ADS)

    Winans, Joshua David

    As the supply of fossil fuels diminishes in quantity the demand for alternative energy sources will consistently increase. Solar cells are an environmentally friendly and proven technology that suffer in sales due to a large upfront cost. In order to help facilitate the transition from fossil fuels to photovoltaics, module costs must be reduced to prices well below $1/Watt. Thin-film solar cells are more affordable because of the reduced materials costs, but lower in efficiency because less light is absorbed before passing through the cell. Silver nanoparticles placed at the front surface of the solar cell absorb and reradiate the energy of the light in ways such that more of the light ends being captured by the silicon. Silver nanoparticles can do this because they have free electron clouds that can take on the energy of an incident photon through collective action. This bulk action of the electrons is called a plasmon. This work begins by discussing the economics driving the need for reduced material use, and the pros and cons of taking this step. Next, the fundamental theory of light-matter interaction is briefly described followed by an introduction to the study of plasmonics. Following that we discuss a traditional method of silver nanoparticle formation and the initial experimental studies of their effects on the ability of thin-film silicon to absorb light. Then, Finite-Difference Time-Domain simulation software is used to simulate the effects of nanoparticle morphology and size on the scattering of light at the surface of the thin-film.

  13. Proton conducting membrane for fuel cells

    DOEpatents

    Colombo, Daniel G.; Krumpelt, Michael; Myers, Deborah J.; Kopasz, John P.

    2007-03-27

    An ion conducting membrane comprising dendrimeric polymers covalently linked into a network structure. The dendrimeric polymers have acid functional terminal groups and may be covalently linked via linking compounds, cross-coupling reactions, or copolymerization reactions. The ion conducting membranes may be produced by various methods and used in fuel cells.

  14. Proton conducting membrane for fuel cells

    DOEpatents

    Colombo, Daniel G.; Krumpelt, Michael; Myers, Deborah J.; Kopasz, John P.

    2005-12-20

    An ion conducting membrane comprising dendrimeric polymers covalently linked into a network structure. The dendrimeric polymers have acid functional terminal groups and may be covalently linked via linking compounds, cross-coupling reactions, or copolymerization reactions. The ion conducting membranes may be produced by various methods and used in fuel cells.

  15. Patterns and conformations in molecularly thin films

    NASA Astrophysics Data System (ADS)

    Basnet, Prem B.

    Molecularly thin films have been a subject of great interest for the last several years because of their large variety of industrial applications ranging from micro-electronics to bio-medicine. Additionally, molecularly thin films can be used as good models for biomembrane and other systems where surfaces are critical. Many different kinds of molecules can make stable films. My research has considered three such molecules: a polymerizable phospholipid, a bent-core molecules, and a polymer. One common theme of these three molecules is chirality. The phospolipid molecules studied here are strongly chiral, which can be due to intrinsically chiral centers on the molecules and also due to chiral conformations. We find that these molecules give rise to chiral patterns. Bent-core molecules are not intrinsically chiral, but individual molecules and groups of molecules can show chiral structures, which can be changed by surface interactions. One major, unconfirmed hypothesis for the polymer conformation at surface is that it forms helices, which would be chiral. Most experiments were carried out at the air/water interface, in what are called Langmuir films. Our major tools for studying these films are Brewster Angle Microscopy (BAM) coupled with the thermodynamic information that can be deduced from surface pressure isotherms. Phospholipids are one of the important constituents of liposomes -- a spherical vesicle com-posed of a bilayer membrane, typically composed of a phospholipid and cholesterol bilayer. The application of liposomes in drug delivery is well-known. Crumpling of vesicles of polymerizable phospholipids has been observed. With BAM, on Langmuir films of such phospholipids, we see novel spiral/target patterns during compression. We have found that both the patterns and the critical pressure at which they formed depend on temperature (below the transition to a i¬‘uid layer). Bent-core liquid crystals, sometimes knows as banana liquid crystals, have drawn

  16. The role of strain and structure on oxygen ion conduction in nanoscale zirconia and ceria thin films

    NASA Astrophysics Data System (ADS)

    Jiang, Jun

    Solid oxide fuel cells (SOFCs), an all solid-state energy conversion device, are promising for their high efficiency and materials stability. The solid oxide electrolytes are a key component that must provide high ionic conductivity, which is especially challenging for intermediate temperature SOFCs operating between 500 °C - 700 °C. Doped zirconia and ceria are the most common solid electrolyte materials. Recent reports have suggested that nanoscale ytrria stabilized zirconia (YSZ) thin films may provide better performance in this regard. However, the mechanism behind the increased conductivity of nanoscale thin films is still unclear and the reported experimental results are controversial. In the thesis presented here, the effects of mechanical strain and microstructure on the ionic conductivity have been investigated in ultrathin zirconia- and ceria-based thin films. Reactive RF co-sputtering with metal targets was used to prepare zirconia and ceria based thin films for high purity, modulated composition and thickness. The films were as thin as 10-20 atomic layers thick. X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy were the main tools to investigate the composition, crystal orientation and microstructure of these sputtered thin films. Microscale interdigitated Pt electrodes were prepared through a lift-off process using photolithography. The electrochemical properties of these sputtered doped zirconia and ceria thin films were investigated using impedance spectroscopy. YSZ thin films deposited on MgO (111) and, especially, MgO (100) showed highly variable crystal orientations, while MgO (110) offered much more stable growth. Regardless of whether the growth was epitaxial or highly disordered polycrystalline, 50 nm thick YSZ thin films on MgO (100), (110), and (111) substrates exhibited similar conductivity with YSZ single crystal. While decreasing the thickness further to 12 nm, the conductivities of YSZ thin films

  17. Dynamical SCFT Simulations of Solvent Annealed Thin Films

    NASA Astrophysics Data System (ADS)

    Paradiso, Sean; Delaney, Kris; Ceniceros, Hector; Garcia-Cervera, Carlos; Fredrickson, Glenn

    2014-03-01

    Block copolymer thin films are ideal candidates for a broad range of technologies including rejection layers for ultrafiltration membranes, proton-exchange membranes in solar cells, optically active coatings, and lithographic masks for bit patterning storage media. Optimizing the performance of these materials often hinges on tuning the orientation and long-range order of the film's internal nanostructure. In response, solvent annealing techniques have been developed for their promise to afford additional flexibility in tuning thin film morphology, but pronounced processing history dependence and a dizzying parameter space have resulted in slow progress towards developing clear design rules for solvent annealing systems. In this talk, we will report recent theoretical progress in understanding the self assembly dynamics relevant to solvent-annealed and solution-cast block copolymer films. Emphasis will be placed on evaporation-induced ordering trends in both the slow and fast drying regimes for cylinder-forming block copolymers from initially ordered and disordered films, along with the role solvent selectivity plays in the ordering dynamics.

  18. Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films

    SciTech Connect

    Hellman, Frances

    1998-10-03

    OAK B204 Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films. The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and hTi-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials.

  19. Thermal and electrical transport in ferromagnetic metal thin films

    NASA Astrophysics Data System (ADS)

    Avery, Azure D.

    The recent emergence of spin caloritronics has focused considerable attention on the interplay between spin, charge, and temperature gradients in magnetic materials. A reliable and energy efficient method for generating pure spin currents would signify an important step toward future spin-based nano-electronics that may offer lower power consumption and greater processing capabilities. To develop new technology using thermoelectric effects in magnetic thin films, it is essential to understand thermal and electrical transport through these films. One possible source of pure spin currents is the so-called spin Seebeck effect (SSE) in which a thermal gradient (▿T) applied to a ferromagnet is thought to produce a pure spin current detectable by measuring a transverse voltage (VT) generated by the inverse spin Hall effect. However, recent work on spin-dependent transport in thin film nanostructures supported by bulk substrates has underscored the difficulty in understanding ▿T in these systems due to uncertainty in the direction of the applied ▿T through a substrate with a thermal conductance several orders of magnitude larger than the sample conductance. These results suggest that early SSE experiments may have been strongly affected by other effects such as the anomalous Nernst effect. They may also have been affected by thermoelectric effects generated from planar thermal gradients such as the planar Nernst effect which develops a VT in a film with a planar ▿T and magnetization. In this dissertation, I introduce the concepts of thermal conductivity, the Wiedemann-Franz law, and thermoelectric effects including the Seebeck effect, the Peltier effect, and the planar Nernst effect (PNE). Next, I describe our experimental method for measuring thermal and electrical transport in non magnetic and ferromagnetic metallic thin films using suspended Si-N membrane structures. Our membrane method reduces the background thermal conductance contribution by 5 orders of

  20. Chemical degradation mechanisms of membranes for alkaline membrane fuel cells

    SciTech Connect

    Choe, Yoong-Kee; Henson, Neil J.; Kim, Yu Seung

    2015-12-31

    Chemical degradation mechanisms of membranes for alkaline membrane fuel cells have been investigated using density functional theory (DFT). We have elucidated that the aryl-ether moiety of membranes is one of the weakest site against attack of hydroxide ions. The results of DFT calculations for hydroxide initiated aryl-ether cleavage indicated that the aryl-ether cleavage occurred prior to degradation of cationic functional group. Such a weak nature of the aryl-ether group arises from the electron deficiency of the aryl group as well as the low bond dissociation energy. The DFT results suggests that removal of the aryl-ether group in the membrane should enhance the stability of membranes under alkaline conditions. In fact, an ether fee poly(phenylene) membrane exhibits excellent stability against the attack from hydroxide ions.

  1. Measuring stiffness and residual stress of thin films by contact resonance atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ma, Chengfu; Chen, Yuhang; Chen, Jianfeng; Chu, Jiaru

    2016-11-01

    A method based on contact resonance atomic force microscopy (AFM) was proposed to determine the mechanical properties of thin films. By analyzing the contact resonance frequencies of an AFM probe while the tip was in contact with the sample, the stiffness and residual stress of a freestanding circular SiN x membrane were evaluated quantitatively. The obtained magnitude of residual stress was in reasonable agreement with that determined by wafer curvature measurement. The method was verified to have much better mechanical sensitivity than the popular AFM bending test method. Its promising application to fast, nondestructive mechanical mapping of thin-film-type structures at the nanoscale was also demonstrated.

  2. Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride – Technology and piezoelectric properties

    SciTech Connect

    Stoeckel, C. Kaufmann, C.; Hahn, R.; Schulze, R.; Billep, D.; Gessner, T.

    2014-07-21

    Pulsed DC magnetron sputtered aluminum nitride (AlN) thin films are prepared on several seed layers and at different sputtering conditions. The piezoelectric c-axis (002) orientation of the AlN is analyzed with X-ray diffraction method. The transverse piezoelectric coefficient d{sub 31} is determined with a Laser-Doppler-Vibrometer at cantilevers and membranes by analytical calculations and finite element method. Additionally, thin film AlN on bulk silicon is used to characterize the longitudinal piezoelectric charge coefficient d{sub 33}.

  3. Pulsed DC magnetron sputtered piezoelectric thin film aluminum nitride - Technology and piezoelectric properties

    NASA Astrophysics Data System (ADS)

    Stoeckel, C.; Kaufmann, C.; Hahn, R.; Schulze, R.; Billep, D.; Gessner, T.

    2014-07-01

    Pulsed DC magnetron sputtered aluminum nitride (AlN) thin films are prepared on several seed layers and at different sputtering conditions. The piezoelectric c-axis (002) orientation of the AlN is analyzed with X-ray diffraction method. The transverse piezoelectric coefficient d31 is determined with a Laser-Doppler-Vibrometer at cantilevers and membranes by analytical calculations and finite element method. Additionally, thin film AlN on bulk silicon is used to characterize the longitudinal piezoelectric charge coefficient d33.

  4. Flexoelectricity in barium strontium titanate thin film

    SciTech Connect

    Kwon, Seol Ryung; Huang, Wenbin; Yuan, Fuh-Gwo; Jiang, Xiaoning; Shu, Longlong; Maria, Jon-Paul

    2014-10-06

    Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.

  5. Thin film hydrous metal oxide catalysts

    DOEpatents

    Dosch, Robert G.; Stephens, Howard P.

    1995-01-01

    Thin film (<100 nm) hydrous metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

  6. Semiconductor cooling by thin-film thermocouples

    NASA Technical Reports Server (NTRS)

    Tick, P. A.; Vilcans, J.

    1970-01-01

    Thin-film, metal alloy thermocouple junctions do not rectify, change circuit impedance only slightly, and require very little increase in space. Although they are less efficient cooling devices than semiconductor junctions, they may be applied to assist conventional cooling techniques for electronic devices.

  7. US polycrystalline thin film solar cells program

    SciTech Connect

    Ullal, H S; Zweibel, K; Mitchell, R L

    1989-11-01

    The Polycrystalline Thin Film Solar Cells Program, part of the United States National Photovoltaic Program, performs R D on copper indium diselenide and cadmium telluride thin films. The objective of the Program is to support research to develop cells and modules that meet the US Department of Energy's long-term goals by achieving high efficiencies (15%-20%), low-cost ($50/m{sup 2}), and long-time reliability (30 years). The importance of work in this area is due to the fact that the polycrystalline thin-film CuInSe{sub 2} and CdTe solar cells and modules have made rapid advances. They have become the leading thin films for PV in terms of efficiency and stability. The US Department of Energy has increased its funding through an initiative through the Solar Energy Research Institute in CuInSe{sub 2} and CdTe with subcontracts to start in Spring 1990. 23 refs., 5 figs.

  8. Thin-Film Nanocapacitor and Its Characterization

    ERIC Educational Resources Information Center

    Hunter, David N.; Pickering, Shawn L.; Jia, Dongdong

    2007-01-01

    An undergraduate thin-film nanotechnology laboratory was designed. Nanocapacitors were fabricated on silicon substrates by sputter deposition. A mask was designed to form the shape of the capacitor and its electrodes. Thin metal layers of Au with a 80 nm thickness were deposited and used as two infinitely large parallel plates for a capacitor.…

  9. Bimodal swelling responses in microgel thin films.

    PubMed

    Sorrell, Courtney D; Lyon, L Andrew

    2007-04-26

    A series of studies on microgel thin films is described, wherein quartz crystal microgravimetry (QCM), surface plasmon resonance (SPR), and atomic force microscopy (AFM) have been used to probe the properties of microstructured polymer thin films as a function of film architecture and solution pH. Thin films composed of pNIPAm-co-AAc microgels were constructed by using spin-coating layer-by-layer (scLbL) assembly with poly(allylamine hydrochloride) (PAH) as a polycationic "glue". Our findings suggest that the interaction between the negatively charged microgels and the positively charged PAH has a significant impact on the pH responsivity of the film. These effects are observable in both the optical and mechanical behaviors of the films. The most significant changes in behavior are observed when the motional resistance of a quartz oscillator is monitored via QCM experiments. Slight changes to the film architecture and alternating the pH of the environment significantly changes the QCM and SPR responses, suggesting a pH-dependent swelling that is dependent on both particle swelling and polyelectrolyte de-complexation. Together, these studies allow for a deeper understanding of the morphological changes that take place in environmentally responsive microgel-based thin films. PMID:17407344

  10. Rechargeable Thin-film Lithium Batteries

    DOE R&D Accomplishments Database

    Bates, J. B.; Gruzalski, G. R.; Dudney, N. J.; Luck, C. F.; Yu, Xiaohua

    1993-08-01

    Rechargeable thin film batteries consisting of lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have recently been developed. The batteries, which are typically less than 6 {mu}m thick, can be fabricated to any specified size, large or small, onto a variety of substrates including ceramics, semiconductors, and plastics. The cells that have been investigated include Li TiS{sub 2}, Li V{sub 2}O{sub 5}, and Li Li{sub x}Mn{sub 2}O{sub 4}, with open circuit voltages at full charge of about 2.5, 3.6, and 4.2, respectively. The development of these batteries would not have been possible without the discovery of a new thin film lithium electrolyte, lithium phosphorus oxynitride, that is stable in contact with metallic lithium at these potentials. Deposited by rf magnetron sputtering of Li{sub 3}PO{sub 4} in N{sub 2}, this material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25{degrees}C of 2 {mu}S/cm. The maximum practical current density obtained from the thin film cells is limited to about 100 {mu}A/cm{sup 2} due to a low diffusivity of Li{sup +} ions in the cathodes. In this work, the authors present a short review of their work on rechargeable thin film lithium batteries.

  11. UV absorption control of thin film growth

    DOEpatents

    Biefeld, Robert M.; Hebner, Gregory A.; Killeen, Kevin P.; Zuhoski, Steven P.

    1991-01-01

    A system for monitoring and controlling the rate of growth of thin films in an atmosphere of reactant gases measures the UV absorbance of the atmosphere and calculates the partial pressure of the gases. The flow of reactant gases is controlled in response to the partial pressure.

  12. Growth induced magnetic anisotropy in crystalline and amorphous thin films

    SciTech Connect

    Hellman, F.

    1998-07-20

    The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and Ni-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials. A brief summary of work done in each area is given.

  13. Preparation of microstructure-controllable superhydrophobic polytetrafluoroethylene porous thin film by vacuum thermal-evaporation

    NASA Astrophysics Data System (ADS)

    Yi, Na; Bao, Shanhu; Zhou, Huaijuan; Xin, Yunchuan; Huang, Aibin; Ma, Yining; Li, Rong; Jin, Ping

    2016-09-01

    The three-dimensional porous network polytetrafluoroethylene (PTFE) thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologies by adjusting the evaporation temperature and the corresponding contact angle ranging from 133° to 155°. Further analyses of surface chemical composition and morphology by FTIR and FE-SEM revealed that the origin of hydrophobicity for the PTFE thin films could be ascribed to the fluorine-containing groups and the surface morphologies, indicating that abundant -CF2 groups and network structures with appropriate pore sizes played a vital role in superhydrophobicity. By characterization of UV-Vis, the films also showed high transmittance and antireflection effect. The films prepared by this simple method have potential applications such as waterproof membrane and self-cleaning coating.

  14. Research and development of proton-exchange membrane (PEM) fuel cell system for transportation applications. Phase I final report

    SciTech Connect

    1996-01-01

    Objective during Phase I was to develop a methanol-fueled 10-kW fuel cell power source and evaluate its feasibility for transportation applications. This report documents research on component (fuel cell stack, fuel processor, power source ancillaries and system sensors) development and the 10-kW power source system integration and test. The conceptual design study for a PEM fuel cell powered vehicle was documented in an earlier report (DOE/CH/10435-01) and is summarized herein. Major achievements in the program include development of advanced membrane and thin-film low Pt-loaded electrode assemblies that in reference cell testing with reformate-air reactants yielded performance exceeding the program target (0.7 V at 1000 amps/ft{sup 2}); identification of oxidation catalysts and operating conditions that routinely result in very low CO levels ({le} 10 ppm) in the fuel processor reformate, thus avoiding degradation of the fuel cell stack performance; and successful integrated operation of a 10-kW fuel cell stack on reformate from the fuel processor.

  15. Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures

    SciTech Connect

    Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M. ); Schultz, J.A. ); Schmidt, H.K. ); Chang, R.P.H. . Dept. of Materials Science)

    1992-01-01

    Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 [Angstrom]), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 [Angstrom] of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

  16. Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures

    SciTech Connect

    Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M.; Schultz, J.A.; Schmidt, H.K.; Chang, R.P.H.

    1992-11-01

    Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 {Angstrom}), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 {Angstrom} of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

  17. High index glass thin film processing for photonics and photovoltaic (PV) applications

    NASA Astrophysics Data System (ADS)

    Ogbuu, Okechukwu Anthony

    To favorably compete with fossil-fuel technology, the greatest challenge for thin film solar-cells is to improve efficiency and reduce material cost. Thickness scaling to thin film reduces material cost but affects the light absorption in the cells; therefore a concept that traps incident photons and increases its optical path length is needed to boost absorption in thin film solar cells. One approach is the integration of low symmetric gratings (LSG), using high index material, on either the front-side or backside of 30 um thin c-Si cells. In this study, Multicomponent TeO2--Bi2O 3--ZnO (TBZ) glass thin films were prepared using RF magnetron sputtering under different oxygen flow rates. The influences of oxygen flow rate on the structural and optical properties of the resulting thin films were investigated. The structural origin of the optical property variation was studied using X-ray diffraction, X-ray photoelectron spectroscopy, Raman Spectroscopy, and transmission electron microscopy. The results indicate that TBZ glass thin film is a suitable material for front side LSG material photovoltaic and photonics applications due to their amorphous nature, high refractive index (n > 2), broad band optical transparency window, low processing temperature. We developed a simple maskless method to pattern sputtered tellurite based glass thin films using unconventional agarose hydrogel mediated wet etching. Conventional wet etching process, while claiming low cost and high throughput, suffers from reproducibility and pattern fidelity issues due to the isotropic nature of wet chemical etching when applied to glasses and polymers. This method overcomes these challenges by using an agarose hydrogel stamp to mediate a conformal etching process. In our maskless method, agarose hydrogel stamps are patterned following a standard soft lithography and replica molding process from micropatterned masters and soaked in a chemical etchant. The micro-scale features on the stamp are

  18. Electrodeposited CuInSe{sub 2} thin film devices

    SciTech Connect

    Raffaelle, R.P.; Mantovani, J.G.; Friedfeld, R.B.; Bailey, S.G.; Hubbard, S.M.

    1997-12-31

    The authors have been investigating the electrochemical deposition of thin films and junctions based on copper indium diselenide (CIS). CIS is considered to be one of the best absorber materials for use in polycrystalline thin film photovoltaic solar cells. Electrodeposition is a simple and inexpensive method for producing thin-film CIS. The authors have produced both p and n type CIS thin films, as well as a CIS pn junction electrodeposited from a single aqueous solution. Optical bandgaps were determined for these thin films using transmission spectroscopy. Current versus voltage characteristics were measured for Schottky barriers on the individual films and for the pn junction.

  19. Thin film bismuth iron oxides useful for piezoelectric devices

    DOEpatents

    Zeches, Robert J.; Martin, Lane W.; Ramesh, Ramamoorthy

    2016-05-31

    The present invention provides for a composition comprising a thin film of BiFeO.sub.3 having a thickness ranging from 20 nm to 300 nm, a first electrode in contact with the BiFeO.sub.3 thin film, and a second electrode in contact with the BiFeO.sub.3 thin film; wherein the first and second electrodes are in electrical communication. The composition is free or essentially free of lead (Pb). The BFO thin film is has the piezoelectric property of changing its volume and/or shape when an electric field is applied to the BFO thin film.

  20. Advanced membrane electrode assemblies for fuel cells

    SciTech Connect

    Kim, Yu Seung; Pivovar, Bryan S

    2014-02-25

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  1. Advanced membrane electrode assemblies for fuel cells

    DOEpatents

    Kim, Yu Seung; Pivovar, Bryan S.

    2012-07-24

    A method of preparing advanced membrane electrode assemblies (MEA) for use in fuel cells. A base polymer is selected for a base membrane. An electrode composition is selected to optimize properties exhibited by the membrane electrode assembly based on the selection of the base polymer. A property-tuning coating layer composition is selected based on compatibility with the base polymer and the electrode composition. A solvent is selected based on the interaction of the solvent with the base polymer and the property-tuning coating layer composition. The MEA is assembled by preparing the base membrane and then applying the property-tuning coating layer to form a composite membrane. Finally, a catalyst is applied to the composite membrane.

  2. Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

    NASA Astrophysics Data System (ADS)

    Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

    2016-06-01

    We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ~ 4.1 Å), and low electrical resistivity (4.2 × 10-4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained "on/off" current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 × 107, 0.43 V/decade, 0.7 V, and 2.1 cm2/V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs.

  3. Hydrogen ion diffusion coefficient of silicon nitride thin films

    NASA Astrophysics Data System (ADS)

    Yu, George T.; Yen, S. K.

    2002-12-01

    Hydrogen ion diffusion in silicon nitride thin film is of significant interest because of its importance in barrier, sensor and catalytic coating applications. In this study, a novel method based on potential-pH response measurement was used to determine hydrogen ion diffusion in silicon nitride thin films. Hydrogen ion diffusion coefficient in silicon nitride films obtained from this method was 1×10 -19 cm 2/s. A potential-pH response drift was observed and is believed to be due to the presence of a hydrated layer affecting the hydrogen ion diffusion onto the nitride film of the Si 3N 4-gate hydrogen ion-sensitive field effect transistors (ISFETs). The unique feature of the potential-pH response method is its relatively simple experimental procedure, which eliminates complications arising from surface-related effects and/or presence of hydrogen traps in membrane, such as those found in the conventional permeation method. The method also offers a considerable test time reduction, with the experiment being completed in 10 h as compared to the conventional electrochemical permeation method which takes as long as 5 days.

  4. Peltier cooling and onsager reciprocity in ferromagnetic thin films.

    PubMed

    Avery, A D; Zink, B L

    2013-09-20

    We present direct measurements of the Peltier effect as a function of temperature from 77 to 325 K in Ni, Ni(80)Fe(20), and Fe thin films made using a suspended Si-N membrane structure. Measurement of the Seebeck effect in the same films allows us to directly test predictions of Onsager reciprocity between the Peltier and Seebeck effects. The Peltier coefficient Π is negative for both Ni and Ni(80)Fe(20) films and positive for the Fe film. The Fe film also exhibits a peak associated with the magnon drag Peltier effect. The observation of magnon drag in the Fe film verifies that the coupling between the phonon, magnon, and electron systems in the film is the same whether driven by heat current or charge current. The excellent agreement between Π values predicted using the experimentally determined Seebeck coefficient for these films and measured values offers direct experimental confirmation of the Onsager reciprocity between these thermoelectric effects in ferromagnetic thin films near room temperature.

  5. Doping in zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Yang, Zheng

    Doping in zinc oxide (ZnO) thin films is discussed in this dissertation. The optimizations of undoped ZnO thin film growth using molecular-beam epitaxy (MBE) are discussed. The effect of the oxygen ECR plasma power on the growth rate, structural, electrical, and optical properties of the ZnO thin films were studied. It was found that larger ECR power leads to higher growth rate, better crystallinity, lower electron carrier concentration, larger resistivity, and smaller density of non-radiative luminescence centers in the ZnO thin films. Low-temperature photoluminescence (PL) measurements were carried out in undoped and Ga-doped ZnO thin films grown by molecular-beam epitaxy. As the carrier concentration increases from 1.8 x 1018 to 1.8 x 1020 cm-3, the dominant PL line at 9 K changes from I1 (3.368--3.371 eV), to IDA (3.317--3.321 eV), and finally to I8 (3.359 eV). The dominance of I1, due to ionized-donor bound excitons, is unexpected in n-type samples, but is shown to be consistent with the temperature-dependent Hall fitting results. We also show that IDA has characteristics of a donor-acceptor-pair transition, and use a detailed, quantitative analysis to argue that it arises from GaZn donors paired with Zn-vacancy (VZn) acceptors. In this analysis, the GaZn0/+ energy is well-known from two-electron satellite transitions, and the VZn0/- energy is taken from a recent theoretical calculation. Typical behaviors of Sb-doped p-type ZnO are presented. The Sb doping mechanisms and preference in ZnO are discussed. Diluted magnetic semiconducting ZnO:Co thin films with above room-temperature TC were prepared. Transmission electron microscopy and x-ray diffraction studies indicate the ZnO:Co thin films are free of secondary phases. The magnetization of the ZnO:Co thin films shows a free electron carrier concentration dependence, which increases dramatically when the free electron carrier concentration exceeds ˜1019 cm -3, indicating a carrier-mediated mechanism for

  6. Issue and challenges facing rechargeable thin film lithium batteries

    SciTech Connect

    Patil, Arun; Patil, Vaishali; Shin, Dong Wook; Choi, Ji-Won; Paik, Dong-Soo; Yoon, Seok-Jin

    2008-08-04

    New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. Technological improvements in rechargeable solid-state batteries are being driven by an ever-increasing demand for portable electronic devices. Lithium batteries are the systems of choice, offering high energy density, flexible, lightweight design and longer lifespan than comparable battery technologies. We present a brief historical review of the development of lithium-based thin film rechargeable batteries highlight ongoing research strategies and discuss the challenges that remain regarding the discovery of nanomaterials as electrolytes and electrodes for lithium batteries also this article describes the possible evolution of lithium technology and evaluates the expected improvements, arising from new materials to cell technology. New active materials under investigation and electrode process improvements may allow an ultimate final energy density of more than 500 Wh/L and 200 Wh/kg, in the next 5-6 years, while maintaining sufficient power densities. A new rechargeable battery technology cannot be foreseen today that surpasses this. This report will provide key performance results for thin film batteries and highlight recent advances in their development.

  7. Influence of Substrate on PFSA Thin-Film Morphology

    NASA Astrophysics Data System (ADS)

    Dudenas, Peter; Kusoglu, Ahmet; Venkatakrishnan, Singanallur; Hexemer, Alexander; Weber, Adam

    Perfluorosulfonic-acid (PFSA) ionomers are the most commonly used electrolyte for polymer-electrolyte fuel cells (PEFCs) due to their high conductivity and good electrochemical and thermo-mechanical stability. A PFSA's chemical structure is comprised of a polytetrafluoroethylene (PTFE) backbone that provides mechanical and chemical stability, and randomly placed tethered perfluoroether side chains terminated with sulfonic-acid groups, which impart its remarkable proton-conduction capabilities. Controlled by substrate/film interactions, long-range structural order in PFSAs change when confined to thin films (<200 nm), as does its transport and mechanical properties. The nature of change is substrate dependent, where stronger interactions create a more dramatic change in properties. In this talk, grazing-incidence c-Ray scattering (GIXS) is used to demonstrate induced structural order on metallic substrates, which is not present on other substrates like silicon and carbon. The higher degree of ordering is correlated with measured changes in mechanical properties for the thin films. Scattering data is also modeled using the recently released program high-performance GISAXS (HipGISAXS), to estimate the size and distribution of the ordered domains. -/a

  8. Polycrystalline thin films FY 1992 project report

    SciTech Connect

    Zweibel, K.

    1993-01-01

    This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting ``next-generation`` options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called ``government/industry partnerships``) that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

  9. Polycrystalline thin films FY 1992 project report

    SciTech Connect

    Zweibel, K.

    1993-01-01

    This report summarizes the activities and results of the Polycrystalline Thin Film Project during FY 1992. The purpose of the DOE/NREL PV (photovoltaic) Program is to facilitate the development of PV that can be used on a large enough scale to produce a significant amount of energy in the US and worldwide. The PV technologies under the Polycrystalline Thin Film project are among the most exciting next-generation'' options for achieving this goal. Over the last 15 years, cell-level progress has been steady, with laboratory cell efficiencies reaching levels of 15 to 16%. This progress, combined with potentially inexpensive manufacturing methods, has attracted significant commercial interest from US and international companies. The NREL/DOE program is designed to support the efforts of US companies through cost-shared subcontracts (called government/industry partnerships'') that we manage and fund and through collaborative technology development work among industry, universities, and our laboratory.

  10. Multiferroic oxide thin films and heterostructures

    NASA Astrophysics Data System (ADS)

    Lu, Chengliang; Hu, Weijin; Tian, Yufeng; Wu, Tom

    2015-06-01

    Multiferroic materials promise a tantalizing perspective of novel applications in next-generation electronic, memory, and energy harvesting technologies, and at the same time they also represent a grand scientific challenge on understanding complex solid state systems with strong correlations between multiple degrees of freedom. In this review, we highlight the opportunities and obstacles in growing multiferroic thin films with chemical and structural integrity and integrating them in functional devices. Besides the magnetoelectric effect, multiferroics exhibit excellent resistant switching and photovoltaic properties, and there are plenty opportunities for them to integrate with other ferromagnetic and superconducting materials. The challenges include, but not limited, defect-related leakage in thin films, weak magnetism, and poor control on interface coupling. Although our focuses are Bi-based perovskites and rare earth manganites, the insights are also applicable to other multiferroic materials. We will also review some examples of multiferroic applications in spintronics, memory, and photovoltaic devices.

  11. Thin film photovoltaic panel and method

    DOEpatents

    Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

    1991-06-11

    A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

  12. Mesoscopically structured nanocrystalline metal oxide thin films

    NASA Astrophysics Data System (ADS)

    Carretero-Genevrier, Adrian; Drisko, Glenna L.; Grosso, David; Boissiere, Cédric; Sanchez, Clement

    2014-11-01

    This review describes the main successful strategies that are used to grow mesostructured nanocrystalline metal oxide and SiO2 films via deposition of sol-gel derived solutions. In addition to the typical physicochemical forces to be considered during crystallization, mesoporous thin films are also affected by the substrate-film relationship and the mesostructure. The substrate can influence the crystallization temperature and the obtained crystallographic orientation due to the interfacial energies and the lattice mismatch. The mesostructure can influence the crystallite orientation, and affects nucleation and growth behavior due to the wall thickness and pore curvature. Three main methods are presented and discussed: templated mesoporosity followed by thermally induced crystallization, mesostructuration of already crystallized metal oxide nanobuilding units and substrate-directed crystallization with an emphasis on very recent results concerning epitaxially grown piezoelectric structured α-quartz films via crystallization of amorphous structured SiO2 thin films.

  13. Induced electronic anisotropy in bismuth thin films

    SciTech Connect

    Liao, Albert D.; Yao, Mengliang; Opeil, Cyril; Katmis, Ferhat; Moodera, Jagadeesh S.; Li, Mingda; Tang, Shuang; Dresselhaus, Mildred S.

    2014-08-11

    We use magneto-resistance measurements to investigate the effect of texturing in polycrystalline bismuth thin films. Electrical current in bismuth films with texturing such that all grains are oriented with the trigonal axis normal to the film plane is found to flow in an isotropic manner. By contrast, bismuth films with no texture such that not all grains have the same crystallographic orientation exhibit anisotropic current flow, giving rise to preferential current flow pathways in each grain depending on its orientation. Extraction of the mobility and the phase coherence length in both types of films indicates that carrier scattering is not responsible for the observed anisotropic conduction. Evidence from control experiments on antimony thin films suggests that the anisotropy is a result of bismuth's large electron effective mass anisotropy.

  14. Generalized Ellipsometry on Ferromagnetic Sculptured Thin Films.

    NASA Astrophysics Data System (ADS)

    Schmidt, Daniel; Hofmann, Tino; Mok, Kah; Schmidt, Heidemarie; Skomski, Ralf; Schubert, Eva; Schubert, Mathias

    2011-03-01

    We present and discuss generalized ellipsometry and generalized vector-magneto-optic ellipsometry investigations on cobalt nanostructured thin films with slanted, highly-spatially coherent, columnar arrangement. The samples were prepared by glancing angle deposition. The thin films are highly transparent and reveal strong form-induced birefringence. We observe giant Kerr rotation in the visible spectral region, tunable by choice of the nanostructure geometry. Spatial magnetization orientation hysteresis and magnetization magnitude hysteresis properties are studied using a 3-dimensional Helmholtz coil arrangement allowing for arbitrary magnetic field direction at the sample position for field strengths up to 0.4 Tesla. Analysis of data obtained within this novel vector-magneto-optic setup reveals magnetization anisotropy of the Co slanted nanocolumns supported by mean-field theory modeling.

  15. Techniques for Connecting Superconducting Thin Films

    NASA Technical Reports Server (NTRS)

    Mester, John; Gwo, Dz-Hung

    2006-01-01

    Several improved techniques for connecting superconducting thin films on substrates have been developed. The techniques afford some versatility for tailoring the electronic and mechanical characteristics of junctions between superconductors in experimental electronic devices. The techniques are particularly useful for making superconducting or alternatively normally conductive junctions (e.g., Josephson junctions) between patterned superconducting thin films in order to exploit electron quantum-tunneling effects. The techniques are applicable to both low-Tc and high-Tc superconductors (where Tc represents the superconducting- transition temperature of a given material), offering different advantages for each. Most low-Tc superconductors are metallic, and heretofore, connections among them have been made by spot welding. Most high-Tc superconductors are nonmetallic and cannot be spot welded. These techniques offer alternatives to spot welding of most low-Tc superconductors and additional solutions to problems of connecting most high-Tc superconductors.

  16. Dynamics of Polymer Thin Film Mixtures

    NASA Astrophysics Data System (ADS)

    Besancon, Brian M.; Green, Peter F.; Soles, Christopher L.

    2006-03-01

    We examined the influence of film thickness and composition on the glass transition temperature (Tg) and mean square atomic displacements (MSD) of thin film mixtures of deuterated polystyrene (dPS) and tetramethyl bisphenol-A polycarbonate (TMPC) on Si/SiOx substrates using incoherent elastic neutron scattering (ICNS). The onset of dissipative motions, such as those associated with the glass transition and sub-Tg relaxations, are manifested as ``kinks'' in the curve of elastic intensity (or MSD) versus temperature. From the relevant kinks, the Tg was determined as a function of composition and of film thickness. The dependence of the Tg on film thickness exhibited qualitatively similar trends, at a given composition, as determined by the ICNS and ellipsometry measurements. However, with increasing PS content, the values of Tg measured by INS were consistently larger then those measured by ellipsometry. These results are examined in light of existing models on the thin film glass transition and component blend dynamics.

  17. Thin film strain gage development program

    NASA Technical Reports Server (NTRS)

    Grant, H. P.; Przybyszewski, J. S.; Anderson, W. L.; Claing, R. G.

    1983-01-01

    Sputtered thin-film dynamic strain gages of 2 millimeter (0.08 in) gage length and 10 micrometer (0.0004 in) thickness were fabricated on turbojet engine blades and tested in a simulated compressor environment. Four designs were developed, two for service to 600 K (600 F) and two for service to 900 K (1200 F). The program included a detailed study of guidelines for formulating strain-gage alloys to achieve superior dynamic and static gage performance. The tests included gage factor, fatigue, temperature cycling, spin to 100,000 G, and erosion. Since the installations are 30 times thinner than conventional wire strain gage installations, and any alteration of the aerodynamic, thermal, or structural performance of the blade is correspondingly reduced, dynamic strain measurement accuracy higher than that attained with conventional gages is expected. The low profile and good adherence of the thin film elements is expected to result in improved durability over conventional gage elements in engine tests.

  18. Domain switching of fatigued ferroelectric thin films

    SciTech Connect

    Tak Lim, Yun; Yeog Son, Jong E-mail: hoponpop@ulsan.ac.kr; Shin, Young-Han E-mail: hoponpop@ulsan.ac.kr

    2014-05-12

    We investigate the domain wall speed of a ferroelectric PbZr{sub 0.48}Ti{sub 0.52}O{sub 3} (PZT) thin film using an atomic force microscope incorporated with a mercury-probe system to control the degree of electrical fatigue. The depolarization field in the PZT thin film decreases with increasing the degree of electrical fatigue. We find that the wide-range activation field previously reported in ferroelectric domains result from the change of the depolarization field caused by the electrical fatigue. Domain wall speed exhibits universal behavior to the effective electric field (defined by an applied electric field minus the depolarization field), regardless of the degree of the electrical fatigue.

  19. Electrostatic Discharge Effects on Thin Film Resistors

    NASA Technical Reports Server (NTRS)

    Sampson, Michael J.; Hull, Scott M.

    1999-01-01

    Recently, open circuit failures of individual elements in thin film resistor networks have been attributed to electrostatic discharge (ESD) effects. This paper will discuss the investigation that came to this conclusion and subsequent experimentation intended to characterize design factors that affect the sensitivity of resistor elements to ESD. The ESD testing was performed using the standard human body model simulation. Some of the design elements to be evaluated were: trace width, trace length (and thus width to length ratio), specific resistivity of the trace (ohms per square) and resistance value. However, once the experiments were in progress, it was realized that the ESD sensitivity of most of the complex patterns under evaluation was determined by other design and process factors such as trace shape and termination pad spacing. This paper includes pictorial examples of representative ESD failure sites, and provides some options for designing thin film resistors that are ESD resistant. The risks of ESD damage are assessed and handling precautions suggested.

  20. EBSD analysis of electroplated magnetite thin films

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Teng, C. L.; Ryan, M. P.; Hartmann, U.; Mücklich, F.

    2010-05-01

    By means of electron backscatter diffraction (EBSD), we analyse the crystallographic orientation of electroplated magnetite thin films on Si/copper substrates. Varying the voltage during the electroplating procedure, the resulting surface properties are differing considerably. While a high voltage produces larger but individual grains on the surface, the surfaces become smoother on decreasing voltage. Good quality Kikuchi patterns could be obtained from all samples; even on individual grains, where the surface and the edges could be measured. The spatial resolution of the EBSD measurement could be increased to about 10 nm; thus enabling a detailed analysis of single magnetite grains. The thin film samples are polycrystalline and do not exhibit a preferred orientation. EBSD reveals that the grain size changes depending on the processing conditions, while the detected misorientation angles stay similar.

  1. Multiferroic oxide thin films and heterostructures

    SciTech Connect

    Lu, Chengliang E-mail: Tao.Wu@kaust.edu.sa; Hu, Weijin; Wu, Tom E-mail: Tao.Wu@kaust.edu.sa; Tian, Yufeng

    2015-06-15

    Multiferroic materials promise a tantalizing perspective of novel applications in next-generation electronic, memory, and energy harvesting technologies, and at the same time they also represent a grand scientific challenge on understanding complex solid state systems with strong correlations between multiple degrees of freedom. In this review, we highlight the opportunities and obstacles in growing multiferroic thin films with chemical and structural integrity and integrating them in functional devices. Besides the magnetoelectric effect, multiferroics exhibit excellent resistant switching and photovoltaic properties, and there are plenty opportunities for them to integrate with other ferromagnetic and superconducting materials. The challenges include, but not limited, defect-related leakage in thin films, weak magnetism, and poor control on interface coupling. Although our focuses are Bi-based perovskites and rare earth manganites, the insights are also applicable to other multiferroic materials. We will also review some examples of multiferroic applications in spintronics, memory, and photovoltaic devices.

  2. MISSE 5 Thin Films Space Exposure Experiment

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.; Kinard, William H.; Jones, James L.

    2007-01-01

    The Materials International Space Station Experiment (MISSE) is a set of space exposure experiments using the International Space Station (ISS) as the flight platform. MISSE 5 is a co-operative endeavor by NASA-LaRC, United Stated Naval Academy, Naval Center for Space Technology (NCST), NASA-GRC, NASA-MSFC, Boeing, AZ Technology, MURE, and Team Cooperative. The primary experiment is performance measurement and monitoring of high performance solar cells for U.S. Navy research and development. A secondary experiment is the telemetry of this data to ground stations. A third experiment is the measurement of low-Earth-orbit (LEO) low-Sun-exposure space effects on thin film materials. Thin films can provide extremely efficacious thermal control, designation, and propulsion functions in space to name a few applications. Solar ultraviolet radiation and atomic oxygen are major degradation mechanisms in LEO. This paper is an engineering report of the MISSE 5 thm films 13 months space exposure experiment.

  3. Electrostatic thin film chemical and biological sensor

    DOEpatents

    Prelas, Mark A.; Ghosh, Tushar K.; Tompson, Jr., Robert V.; Viswanath, Dabir; Loyalka, Sudarshan K.

    2010-01-19

    A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

  4. Substrate heater for thin film deposition

    DOEpatents

    Foltyn, Steve R.

    1996-01-01

    A substrate heater for thin film deposition of metallic oxides upon a target substrate configured as a disk including means for supporting in a predetermined location a target substrate configured as a disk, means for rotating the target substrate within the support means, means for heating the target substrate within the support means, the heating means about the support means and including a pair of heating elements with one heater element situated on each side of the predetermined location for the target substrate, with one heater element defining an opening through which desired coating material can enter for thin film deposition and with the heating means including an opening slot through which the target substrate can be entered into the support means, and, optionally a means for thermal shielding of the heating means from surrounding environment is disclosed.

  5. Electrochemical Analysis of Conducting Polymer Thin Films

    PubMed Central

    Vyas, Ritesh N.; Wang, Bin

    2010-01-01

    Polyelectrolyte multilayers built via the layer-by-layer (LbL) method has been one of the most promising systems in the field of materials science. Layered structures can be constructed by the adsorption of various polyelectrolyte species onto the surface of a solid or liquid material by means of electrostatic interaction. The thickness of the adsorbed layers can be tuned precisely in the nanometer range. Stable, semiconducting thin films are interesting research subjects. We use a conducting polymer, poly(p-phenylene vinylene) (PPV), in the preparation of a stable thin film via the LbL method. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize the ionic conductivity of the PPV multilayer films. The ionic conductivity of the films has been found to be dependent on the polymerization temperature. The film conductivity can be fitted to a modified Randle’s circuit. The circuit equivalent calculations are performed to provide the diffusion coefficient values. PMID:20480052

  6. Silver nanowire composite thin films as transparent electrodes for Cu(In,Ga)Se₂/ZnS thin film solar cells.

    PubMed

    Tan, Xiao-Hui; Chen, Yu; Liu, Ye-Xiang

    2014-05-20

    Solution processed silver nanowire indium-tin oxide nanoparticle (AgNW-ITONP) composite thin films were successfully applied as the transparent electrodes for Cu(In,Ga)Se₂ (CIGS) thin film solar cells with ZnS buffer layers. Properties of the AgNW-ITONP thin film and its effects on performance of CIGS/ZnS thin film solar cells were studied. Compared with the traditional sputtered ITO electrodes, the AgNW-ITONP thin films show comparable optical transmittance and electrical conductivity. Furthermore, the AgNW-ITONP thin film causes no physical damage to the adjacent surface layer and does not need high temperature annealing, which makes it very suitable to use as transparent conductive layers for heat or sputtering damage-sensitive optoelectronic devices. By using AgNW-ITONP electrodes, the required thickness of the ZnS buffer layers for CIGS thin film solar cells was greatly decreased. PMID:24922214

  7. Microstructure Related Properties of Optical Thin Films.

    NASA Astrophysics Data System (ADS)

    Wharton, John James, Jr.

    Both the optical and physical properties of thin film optical interference coatings depend upon the microstructure of the deposited films. This microstructure is strongly columnar with voids between the columns. Computer simulations of the film growth process indicate that the two most important factors responsible for this columnar growth are a limited mobility of the condensing molecules and self-shadowing by molecules already deposited. During the vacuum deposition of thin films, the microstructure can be influenced by many parameters, such as substrate temperature and vacuum pressure. By controlling these parameters and introducing additional ones, thin film coatings can be improved. In this research, ultraviolet irradiation and ion bombardment were examined as additional parameters. Past studies have shown that post-deposition ultraviolet irradiation can be used to relieve stress and reduce absorption in the far ultraviolet of silicon dioxide films. Ion bombardment has been used to reduce stress, improve packing density, and increase resistance to moisture penetration. Three refractory oxide materials commonly used in thin film coatings were studied; they are silicon dioxide, titanium dioxide, and zirconium dioxide. Both single-layer films and narrowband filters made of these materials were examined. A 1000-watt mercury-xenon lamp was used to provide ultraviolet irradiation. An inverted magnetron ion source was used to produce argon and oxygen ions. Ultraviolet irradiation was found to reduce the absorption and slightly increase the index of refraction in zirconium oxide films. X-ray diffraction analysis revealed that ultraviolet irradiation caused titanium oxide films to become more amorphous; their absorption in the ultraviolet was slightly reduced. No changes were noted in film durability. Ion bombardment enhanced the tetragonal (lll) peak of zirconium oxide but increased the absorption of both zirconium oxide and titanium oxide films. The titanium oxide

  8. Packaging material for thin film lithium batteries

    DOEpatents

    Bates, John B.; Dudney, Nancy J.; Weatherspoon, Kim A.

    1996-01-01

    A thin film battery including components which are capable of reacting upon exposure to air and water vapor incorporates a packaging system which provides a barrier against the penetration of air and water vapor. The packaging system includes a protective sheath overlying and coating the battery components and can be comprised of an overlayer including metal, ceramic, a ceramic-metal combination, a parylene-metal combination, a parylene-ceramic combination or a parylene-metal-ceramic combination.

  9. Perovskite thin films via atomic layer deposition.

    PubMed

    Sutherland, Brandon R; Hoogland, Sjoerd; Adachi, Michael M; Kanjanaboos, Pongsakorn; Wong, Chris T O; McDowell, Jeffrey J; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J; Sargent, Edward H

    2015-01-01

    A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3 NH3 PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm(-1) .

  10. Cellulose triacetate, thin film dielectric capacitor

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1993-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  11. Annealed CVD molybdenum thin film surface

    DOEpatents

    Carver, Gary E.; Seraphin, Bernhard O.

    1984-01-01

    Molybdenum thin films deposited by pyrolytic decomposition of Mo(CO).sub.6 attain, after anneal in a reducing atmosphere at temperatures greater than 700.degree. C., infrared reflectance values greater than reflectance of supersmooth bulk molybdenum. Black molybdenum films deposited under oxidizing conditions and annealed, when covered with an anti-reflecting coating, approach the ideal solar collector characteristic of visible light absorber and infrared energy reflector.

  12. Thin-film optical shutter. Final report

    SciTech Connect

    Matlow, S.L.

    1981-02-01

    A specific embodiment of macroconjugated macromolecules, the poly (p-phenylene)'s, has been chosen as the one most likely to meet all of the requirements of the Thin Film Optical Shutter project (TFOS). The reason for this choice is included. In order to be able to make meaningful calculations of the thermodynamic and optical properties of the poly (p-phenylene)'s a new quantum mechanical method was developed - Equilibrium Bond Length (EBL) Theory. Some results of EBL Theory are included.

  13. Large-area thin-film modules

    NASA Technical Reports Server (NTRS)

    Tyan, Y. S.; Perez-Albuerne, E. A.

    1985-01-01

    The low cost potential of thin film solar cells can only be fully realized if large area modules can be made economically with good production yields. This paper deals with two of the critical challenges. A scheme is presented which allows the simple, economical realization of the long recognized, preferred module structure of monolithic integration. Another scheme reduces the impact of shorting defects and, as a result, increases the production yields. Analytical results demonstrating the utilization and advantages of such schemes are discussed.

  14. Superconducting thin films on potassium tantalate substrates

    DOEpatents

    Feenstra, Roeland; Boatner, Lynn A.

    1992-01-01

    A superconductive system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

  15. Stable freestanding thin films of pure water

    SciTech Connect

    Weon, B. M.; Je, J. H.; Hwu, Y.; Margaritondo, G.

    2008-03-10

    Obtaining water microstructures is very difficult because of low viscosity and high surface tension. We produced stable freestanding thin films of pure water by x-ray bombardment of small liquid volumes in capillary tubes. A detailed characterization with phase-contrast radiology demonstrated a lifetime beyond 1 h with no chemical stabilizer for micron-thickness films with half-millimeter-level diameter. This can be attributed to the interplay of two x-ray effects: water evaporation and surface charging.

  16. Thin film dynamics of viscoelastic fluids

    NASA Astrophysics Data System (ADS)

    Lebon, Luc; Limat, Laurent

    2012-11-01

    We present here viscoelastic fluids in thin film flows, such as liquid bells or liquid curtains. The viscoelastic property of the liquids exhibits specific dynamics in such flows. In the case of bells, the elastic strength tends to extend the bell size for example. In the case of curtain flows, original behaviour of holes are observed with specific growth mechanism for bubbles trapped in the flow.

  17. Cellulose triacetate, thin film dielectric capacitor

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S. (Inventor); Jow, T. Richard (Inventor)

    1995-01-01

    Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

  18. Fuel cell subassemblies incorporating subgasketed thrifted membranes

    DOEpatents

    Iverson, Eric J.; Pierpont, Daniel M.; Yandrasits, Michael A.; Hamrock, Steven J.; Obradovich, Stephan J.; Peterson, Donald G.

    2013-03-01

    A fuel cell roll good subassembly is described that includes a plurality of individual electrolyte membranes. One or more first subgaskets are attached to the individual electrolyte membranes. Each of the first subgaskets has at least one aperture and the first subgaskets are arranged so the center regions of the individual electrolyte membranes are exposed through the apertures of the first subgaskets. A second subgasket comprises a web having a plurality of apertures. The second subgasket web is attached to the one or more first subgaskets so the center regions of the individual electrolyte membranes are exposed through the apertures of the second subgasket web. The second subgasket web may have little or no adhesive on the subgasket surface facing the electrolyte membrane.

  19. Fuel cell subassemblies incorporating subgasketed thrifted membranes

    DOEpatents

    Iverson, Eric J; Pierpont, Daniel M; Yandrasits, Michael A; Hamrock, Steven J; Obradovich, Stephan J; Peterson, Donald G

    2014-01-28

    A fuel cell roll good subassembly is described that includes a plurality of individual electrolyte membranes. One or more first subgaskets are attached to the individual electrolyte membranes. Each of the first subgaskets has at least one aperture and the first subgaskets are arranged so the center regions of the individual electrolyte membranes are exposed through the apertures of the first subgaskets. A second subgasket comprises a web having a plurality of apertures. The second subgasket web is attached to the one or more first subgaskets so the center regions of the individual electrolyte membranes are exposed through the apertures of the second subgasket web. The second subgasket web may have little or no adhesive on the subgasket surface facing the electrolyte membrane.

  20. Alternate Fuel Cell Membranes for Energy Independence

    SciTech Connect

    Storey, Robson, F.; Mauritz, Kenneth, A.; Patton, Derek, L.; Savin, Daniel, A.

    2012-12-18

    The overall objective of this project was the development and evaluation of novel hydrocarbon fuel cell (FC) membranes that possess high temperature performance and long term chemical/mechanical durability in proton exchange membrane (PEM) fuel cells (FC). The major research theme was synthesis of aromatic hydrocarbon polymers of the poly(arylene ether sulfone) (PAES) type containing sulfonic acid groups tethered to the backbone via perfluorinated alkylene linkages and in some cases also directly attached to the phenylene groups along the backbone. Other research themes were the use of nitrogen-based heterocyclics instead of acid groups for proton conduction, which provides high temperature, low relative humidity membranes with high mechanical/thermal/chemical stability and pendant moieties that exhibit high proton conductivities in the absence of water, and synthesis of block copolymers consisting of a proton conducting block coupled to poly(perfluorinated propylene oxide) (PFPO) blocks. Accomplishments of the project were as follows: 1) establishment of a vertically integrated program of synthesis, characterization, and evaluation of FC membranes, 2) establishment of benchmark membrane performance data based on Nafion for comparison to experimental membrane performance, 3) development of a new perfluoroalkyl sulfonate monomer, N,N-diisopropylethylammonium 2,2-bis(p-hydroxyphenyl) pentafluoropropanesulfonate (HPPS), 4) synthesis of random and block copolymer membranes from HPPS, 5) synthesis of block copolymer membranes containing high-acid-concentration hydrophilic blocks consisting of HPPS and 3,3'-disulfonate-4,4'-dichlorodiphenylsulfone (sDCDPS), 6) development of synthetic routes to aromatic polymer backbones containing pendent 1H-1,2,3-triazole moieties, 7) development of coupling strategies to create phase-separated block copolymers between hydrophilic sulfonated prepolymers and commodity polymers such as PFPO, 8) establishment of basic performance

  1. Bendable, free-standing calcite thin films.

    PubMed

    Nakamura, Shiho; Naka, Kensuke

    2015-02-17

    Since the hardness and toughness of natural nacre are determined by hierarchical microstructures with organic matters, it is of great importance to control the microstructures of artificial free-standing CaCO3 thin films. However, the fabrication of such films has so far been quite limited, to the extent that their mechanical properties have not been reported. To address this, free-standing calcite thin films were prepared through repeated cycles of layer-by-layer deposition of vaterite precursor composite particles with organic polymers, followed by a phase transition to calcite. In this way, two distinct calcite thin film types were produced based on either 3.2 or 1.0 wt % organic material, with subsequent three-point bending tests revealing that both exhibit elastic bending prior to fracture. More importantly, by increasing the organic content from 1.0 to 3.2 wt %, the bending strength increased from 0.95 ± 0.26 MPa to 1.90 ± 0.21 MPa. PMID:25621634

  2. Photoelectrochemical activity of titanium dioxide thin films

    NASA Astrophysics Data System (ADS)

    Mehdinezhad Roshan, Aida

    Crystalline titanium dioxide (TiO2) thin films have been extensively investigated due to their various applications in a wide range of field such as photocatalysis, solar cells, gas sensors, self-cleaning windows, etc. The general objective of the present work can be categorized into two different parts. The first part of research is to acquire a fundamental understanding of thin film deposition and characterization of materials surfaces produced by Electrolytic Plasma Processing (EPP) and Magnetron Sputtering system. It has been tried to develop a crystalline layer of titanium dioxide thin film using these two techniques. Aluminum and titanium are the substrate materials. Also a part of study is to clean and roughen the substrate prior to the deposition to examine the effect of morphology. Aluminum was chosen as the substrate as well as titanium in order to enable us to get cheaper product. Second main portion of this work is to check the photoelectrochemical response of the deposited film and explore the effect of various parameters of coating process on this photoelectrochemical response.

  3. Thin films, asphaltenes, and reservoir wettability

    SciTech Connect

    Kaminsky, R.; Bergeron, V.; Radke, C.J. |

    1993-04-01

    Reservoir wettability impacts the success of oil recovery by waterflooding and other methods. To understand wettability and its alteration, thin-film forces in solid-aqueous-oil systems must be elucidated. Upon rupture of thick aqueous films separating the oil and rock phases, asphaltene components in the crude oil adsorb irreversibly on the solid surface, changing it from water-wet to oil-wet. Conditions of wettability alteration can be found by performing adhesion tests, in which an oil droplet is brought into contact with a solid surface. Exceeding a critical capillary pressure destabilizes the film, causing spontaneous film rupture to a molecularly adsorbed layer and oil adhesion accompanied by pinning at the three-phase contact line. The authors conduct adhesion experiments similar to those of Buckley and Morrow and simultaneously examine the state of the underlying thin film using optical microscopy and microinterferometry. Aqueous thin films between an asphaltic Orcutt crude oil and glass surfaces are studied as a function of aqueous pH and salinity. For the first time, they prove experimentally that strongly water-wet to strongly oil-wet wettability alteration and contact-angle pinning occur when thick aqueous films thin to molecularly adsorbed films and when the oil phase contains asphaltene molecules.

  4. Design and characterization of thin film microcoolers

    NASA Astrophysics Data System (ADS)

    LaBounty, Chris; Shakouri, Ali; Bowers, John E.

    2001-04-01

    Thin film coolers can provide large cooling power densities compared to bulk thermoelectrics due to the close spacing of hot and cold junctions. Important parameters in the design of such coolers are investigated theoretically and experimentally. A three-dimensional (3D) finite element simulator (ANSYS) is used to model self-consistently thermal and electrical properties of a complete device structure. The dominant three-dimensional thermal and electrical spreading resistances acquired from the 3D simulation are also used in a one-dimensional model (MATLAB) to obtain faster, less rigorous results. Heat conduction, Joule heating, thermoelectric and thermionic cooling are included in these models as well as nonideal effects such as contact resistance, finite thermal resistance of the substrate and the heat sink, and heat generation in the wire bonds. Simulations exhibit good agreement with experimental results from InGaAsP-based thin film thermionic emission coolers which have demonstrated maximum cooling of 1.15 °C at room temperature. With the nonideal effects minimized, simulations predict that single stage thin film coolers can provide up to 20-30 °C degrees centigrade cooling with cooling power densities of several 1000 W/cm2.

  5. Molecular theory of liquid crystal thin films

    NASA Astrophysics Data System (ADS)

    Meng, Shihong

    A molecular theory has been developed to describe the isotropic-nematic transitoon of model nematogens in bulk and in thin films. The surfaces of thin films can be hard surfaces or coated with surfactant monolayers. The theory only includes hard body interactions between all molecule species: solvent, nematogens and surfactants. We have studied the influence of the separation between confining walls, concentration of nematogens, as well as the surface anchoring and areal density of surfactant at the interface upon the phases of nematogens. We have explained the possible existence of planar degenerate phase through entropic pictures and have confirmed close to the bulk isotropic-nematic transition point, the order of the phases of nematogens from isotropic to nematic then back to isotropic when varying the areal density of surfactant monolayers at interfaces. From the results obtained, we believe that we have captured the main competing interactions between surfactants and nematogens and our molecular level theory is capable of describing these two interactions of different natures. Our results can provide a guideline for molecular design of biosensors. We have modeled the molecular systems with as much simplification as possible while retaining the main features. The thesis is arranged into introduction, results on bulk, thin films confined between hard walls and between surfactant monolayers.

  6. Deuterium storage in nanocrystalline magnesium thin films

    NASA Astrophysics Data System (ADS)

    Checchetto, R.; Bazzanella, N.; Miotello, A.; Brusa, R. S.; Zecca, A.; Mengucci, A.

    2004-02-01

    Nanocrystalline magnesium deuteride thin films with the β-MgD2 structure were prepared by vacuum evaporation of hexagonal magnesium (h-Mg) samples and thermal annealing in 0.15 MPa D2 atmosphere at 373 K. Thermal desorption spectroscopy analysis indicated that the rate-limiting step in the deuterium desorption was given by the thermal decomposition of the deuteride phase. The activation energy Δg of the β-MgD2→h-Mg+D2 reaction scaled from 1.13±0.03 eV in 650-nm-thick films to 1.01±0.02 eV in 75-nm-thick films most likely as consequence of different stress and defect level. Positron annihilation spectroscopy analysis of the thin-film samples submitted to deuterium absorption and desorption cycles reveal the presence of a high concentration of void-like defects in the h-Mg layers after the very first decomposition of the β-MgD2 phase, the presence of these open volume defects reduces the D2 absorption capacity of the h-Mg thin film.

  7. Polycrystalline thin film materials and devices

    SciTech Connect

    Baron, B.N.; Birkmire, R.W.; Phillips, J.E.; Shafarman, W.N.; Hegedus, S.S.; McCandless, B.E. . Inst. of Energy Conversion)

    1992-10-01

    Results of Phase II of a research program on polycrystalline thin film heterojunction solar cells are presented. Relations between processing, materials properties and device performance were studied. The analysis of these solar cells explains how minority carrier recombination at the interface and at grain boundaries can be reduced by doping of windows and absorber layers, such as in high efficiency CdTe and CuInSe{sub 2} based solar cells. The additional geometric dimension introduced by the polycrystallinity must be taken into consideration. The solar cells are limited by the diode current, caused by recombination in the space charge region. J-V characteristics of CuInSe{sub 2}/(CdZn)S cells were analyzed. Current-voltage and spectral response measurements were also made on high efficiency CdTe/CdS thin film solar cells prepared by vacuum evaporation. Cu-In bilayers were reacted with Se and H{sub 2}Se gas to form CuInSe{sub 2} films; the reaction pathways and the precursor were studied. Several approaches to fabrication of these thin film solar cells in a superstrate configuration were explored. A self-consistent picture of the effects of processing on the evolution of CdTe cells was developed.

  8. Modification and evaluation of fuel cell membranes

    NASA Astrophysics Data System (ADS)

    Nalawade, Amol Prataprao

    The primary goals of this study were modification of existing NafionRTM membranes and characterization of newly developed hydrocarbon-based membranes for high temperature fuel cell applications. Various NafionRTM/silicate nanocomposites were formulated via in situ sol-gel reactions for tetraethylorthosilicate. Different silicate composition profiles generated across membrane cross-sections were investigated by EDAX/ESEM. Composite water uptake, proton conductivity and fuel cell performance were comparable to that of unmodified Nafion RTM. Tafel analysis showed better electrode kinetics for composites having more silicate in the middle and less or no silicate at electrolyte-electrode interfaces. All composites showed reduced fuel cross-over and superior mechanical as well as chemical durability than unmodified NafionRTM. Poly(cyclohexadiene) (PCHD) materials were characterized in the interest of developing alternative low-cost proton exchange membranes. All cross-linked sulfonated (xsPCHD) membranes showed significantly higher water uptake at 80 °C and higher proton conductivity at 120 °C at all relative humidities (RH), compared to the current benchmark membrane, NafionRTM. A xsPCHD-poly(ethylene glycol) (PEG) copolymer and a xsPCHD-PEG blend surpassed the DOE target by exhibiting proton conductivities of 141.44 and 322.40 mS/cm, respectively, at 50 % RH. Although the PCHD-based PEMs exhibited thermal stability up to 150 °C, they showed poor mechanical properties which would cause poor membrane durability during fuel cell operation. Atomic force microscopy studies demonstrated nanophase separated morphology of xsPCHD having a higher degree of connectedness of hydrophilic domains in the copolymer and blends relative to the xsPCHD homopolymer. Broadband dielectric spectroscopy (BDS) was used to study sub-Tg relaxations in annealed poly(2,5-benzimidazole) (ABPBI) fuel cell precursor materials. A trend in degree of connectivity of charge migration pathways and

  9. Electrochemical protection of thin film electrodes in solid state nanopores.

    PubMed

    Harrer, Stefan; Waggoner, Philip S; Luan, Binquan; Afzali-Ardakani, Ali; Goldfarb, Dario L; Peng, Hongbo; Martyna, Glenn; Rossnagel, Stephen M; Stolovitzky, Gustavo A

    2011-07-01

    Solid state nanopores are a core element of next-generation single molecule tools in the field of nano-biotechnology. Thin film electrodes integrated into a pore can interact with charges and fields within the pore. In order to keep the nanopore open and thus functional electrochemically induced surface alteration of electrode surfaces and bubble formation inside the pore have to be eliminated. This paper provides electrochemical analyses of nanopores drilled into TiN membranes which in turn were employed as thin film electrodes. We studied physical pore integrity and the occurrence of water decomposition yielding bubble formation inside pores by applying voltages between -4.5 and +4.5 V to membranes in various protection stages continuously for up to 24 h. During potential application pores were exposed to selected electrolyte-solvent systems. We have investigated and successfully eliminated electrochemical pore oxidation and reduction as well as water decomposition inside nanopores of various diameters ranging from 3.5 to 25 nm in 50 nm thick TiN membranes by passivating the nanopores with a plasma-oxidized layer and using a 90% solution of glycerol in water as KCl solvent. Nanopore ionic conductances were measured before and after voltage application in order to test for changes in pore diameter due to electrochemical oxidation or reduction. TEM imaging was used to confirm these observations. While non-passivated pores were electrochemically oxidized, neither electrochemical oxidation nor reduction was observed for passivated pores. Bubble formation through water decomposition could be detected in non-passivated pores in KCl/water solutions but was not observed in 90% glycerol solutions. The use of a protective self-assembled monolayer of hexadecylphosphonic acid (HDPA) was also investigated.

  10. Chitosan in nanostructured thin films.

    PubMed

    Pavinatto, Felippe J; Caseli, Luciano; Oliveira, Osvaldo N

    2010-08-01

    This review paper brings an overview of the use of chitosans in nanostructured films produced with the Langmuir-Blodgett (LB) or the electrostatic layer-by-layer (LbL) techniques, with emphasis on their possible applications. From a survey in the literature one may identify three main types of study with chitosan in nanostructured films. First, the interaction between chitosans and phospholipid Langmuir monolayers has been investigated for probing the mechanisms of chitosan action in their biological applications, with the monolayers serving as cell membrane models. In the second type, chitosan serves as a matrix for immobilization of biomolecules in LB as well as in LbL films, for which chitosan is suitable to help preserve the bioactivity of such biomolecules for long periods of time even in dry, solid films. An important application of these chitosan-containing films is in sensing and biosensing. The third type of study involves exploiting the mechanical and biocompatibility properties of chitosan in producing films with enhanced properties, for example, for tissue engineering. It is emphasized that chitosans have been proven excellent building blocks to produce films with controlled molecular architecture, allowing for synergy between distinct materials. We also discuss the prospects of the field, following a critical review of the latest developments in nanostructured chitosan films. PMID:20590156

  11. Membrane electrode assembly for a fuel cell

    NASA Technical Reports Server (NTRS)

    Prakash, Surya (Inventor); Narayanan, Sekharipuram R. (Inventor); Atti, Anthony (Inventor); Olah, George (Inventor); Smart, Marshall C. (Inventor)

    2006-01-01

    A catalyst ink for a fuel cell including a catalytic material and poly(vinylidene fluoride). The ink may be applied to a substrate to form an electrode, or bonded with other electrode layers to form a membrane electrode assembly (MEA).

  12. PZT thin films for piezoelectric MEMS mechanical energy harvesting

    NASA Astrophysics Data System (ADS)

    Yeager, Charles

    damage to the PZT film. An energy harvester was fabricated by etching the MgO substrate down to 10-20 mum under a circular diaphragm device; this structure had a natural frequency of 2.7 kHz and was estimated to provide a maximum RMS power of 8.8 muW/cm2-g2. Due to the lack of selectivity in the patterning, MgO was not as versatile as silicon substrates, which can be etched rapidly by wet and dry methods. To successfully release a PZT film onto a polymer passive elastic layer, dry (gas) etch methods were preferable. This protected the interfacial bonding between PZT films and Parylene. A 2 cm2 thin film membrane (15 mum Parylene/ 3 mum Cyclotene 4022/ 0.1 mum Pt-Ti/ 1.4 mum PZT (52/48)/ 0.14 mum Pt-Ti/ 1 mum SiO2) was released from a silicon substrate and operated with a 5 Hz natural frequency, the lowest reported for a thin film energy harvester operating in resonant excitation. Though problems existed with buckling of the beam due to tension in the Cyclotene 4022 (a benzocyclobutene, BCB, resin) from curing on a silicon substrate, the cantilevered device was calculated to output up to RMS 0.53 muW/cm2 when swept through an arc >30°. Silicon substrates facilitated scaling in size and quantity of devices compared to MgO substrates, which motivated an investigation into the reduction of 90° domain walls for thin films released from substrate clamping conditions. Circular test structures were designed to produce systematic changes in the clamping condition of {001} PZT thin films. The stiffness of the substrate interface was modified either by using a PZT buffer layer on the substrate or by removing the substrate completely. Films allowed to stress relax upon release, via curling, had reduced domain wall restoring force compared to fully clamped structures, leading to a 72% increase in irreversible domain wall contributions for freestanding 300 mum features. The irreversible dielectric Raleigh coefficient, alpha, for a 1.64 mum {001} PZT film measured at 20 Hz increased

  13. Advanced Fabrication Method for the Preparation of MOF Thin Films: Liquid-Phase Epitaxy Approach Meets Spin Coating Method.

    PubMed

    Chernikova, Valeriya; Shekhah, Osama; Eddaoudi, Mohamed

    2016-08-10

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Therefore, paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology. PMID:27415640

  14. Catalytic membranes for fuel cells

    DOEpatents

    Liu, Di-Jia; Yang, Junbing; Wang, Xiaoping

    2011-04-19

    A fuel cell of the present invention comprises a cathode and an anode, one or both of the anode and the cathode including a catalyst comprising a bundle of longitudinally aligned graphitic carbon nanotubes including a catalytically active transition metal incorporated longitudinally and atomically distributed throughout the graphitic carbon walls of said nanotubes. The nanotubes also include nitrogen atoms and/or ions chemically bonded to the graphitic carbon and to the transition metal. Preferably, the transition metal comprises at least one metal selected from the group consisting of Fe, Co, Ni, Mn, and Cr.

  15. Polymer crystallization in thin films: morphology and physical properties

    NASA Astrophysics Data System (ADS)

    Kelly, Giovanni; Albert, Julie

    Polymer crystallization has been studied both computationally and experimentally for decades, elucidating many of the mysteries surrounding crystallization kinetics and thermodynamics. However, many unanswered questions remain pertaining to the relationships between crystallization phenomena and material properties needed for specific applications that range from drug delivery and tissue engineering to optical devices and mechanically robust membranes. One of the especially interesting facets of polymer crystallization is the behavior observed when these long chain molecules are spatially confined in thin and ultrathin films. Confined geometry leads to chain configurations, and therefore thermal, mechanical, and optical properties, sometimes far removed from reported bulk values. This project aims to study the phenomena exhibited by linear semi-crystalline polymers in thin films as well as the way in which blending with homopolymers, block copolymers, and novel polymer chain architectures affect morphology, biodegradation, optical, thermal, and mechanical properties.

  16. A Multilayered Thin Film Insulator for Harsh Environments

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Fralick, Gustave C.; Blaha, Charles A.; Busfield, A. Rachel; Thomas, Valarie D.

    2002-01-01

    The status of work to develop a reliable high temperature dielectric thin film for use with thin film sensors is presented. The use of thin films to electrically insulate thin film sensors on engine components minimizes the intrusiveness of the sensor and allows a more accurate measurement of the environment. A variety of insulating films were investigated for preventing electrical shorting caused by insulator failure between the sensor and the component. By alternating layers of sputtered high temperature ceramics, a sequence of insulating layers was devised that prevents pinholes from forming completely through the insulator and maintains high electrical resistivity at high temperatures. The major technical challenge remaining is to optimize the fabrication of the insulator with respect to composition to achieve a reliable high temperature insulating film. Data from the testing of various potentially insulating thin film systems is presented and their application to thin film sensors is also discussed.

  17. Metallic Thin-Film Bonding and Alloy Generation

    NASA Technical Reports Server (NTRS)

    Fryer, Jack Merrill (Inventor); Campbell, Geoff (Inventor); Peotter, Brian S. (Inventor); Droppers, Lloyd (Inventor)

    2016-01-01

    Diffusion bonding a stack of aluminum thin films is particularly challenging due to a stable aluminum oxide coating that rapidly forms on the aluminum thin films when they are exposed to atmosphere and the relatively low meting temperature of aluminum. By plating the individual aluminum thin films with a metal that does not rapidly form a stable oxide coating, the individual aluminum thin films may be readily diffusion bonded together using heat and pressure. The resulting diffusion bonded structure can be an alloy of choice through the use of a carefully selected base and plating metals. The aluminum thin films may also be etched with distinct patterns that form a microfluidic fluid flow path through the stack of aluminum thin films when diffusion bonded together.

  18. Low-Cost Detection of Thin Film Stress during Fabrication

    NASA Technical Reports Server (NTRS)

    Nabors, Sammy A.

    2015-01-01

    NASA's Marshall Space Flight Center has developed a simple, cost-effective optical method for thin film stress measurements during growth and/or subsequent annealing processes. Stress arising in thin film fabrication presents production challenges for electronic devices, sensors, and optical coatings; it can lead to substrate distortion and deformation, impacting the performance of thin film products. NASA's technique measures in-situ stress using a simple, noncontact fiber optic probe in the thin film vacuum deposition chamber. This enables real-time monitoring of stress during the fabrication process and allows for efficient control of deposition process parameters. By modifying process parameters in real time during fabrication, thin film stress can be optimized or controlled, improving thin film product performance.

  19. Thin-film silicon for flexible metal-air batteries.

    PubMed

    Garamoun, Ahmed; Schubert, Markus B; Werner, Jürgen H

    2014-12-01

    Due to its high energy density, theoretical studies propose silicon as a promising candidate material for metal-air batteries. Herein, for the first time, experimental results detail the use of n-type doped amorphous silicon and silicon carbide as fuel in Si-air batteries. Thin-film silicon is particularly interesting for flexible and rolled batteries with high specific energies. Our Si-air batteries exhibit a specific capacity of 269 Ah kg(-1) and an average cell voltage of 0.85 V at a discharge current density of 7.9 μA cm(-2) , corresponding to a specific energy of 229 Wh kg(-1) . Favorably in terms of safety, low concentrated alkaline solution serves as electrolyte. Discharging of the Si-air cells continues as long as there is silicon available for oxidation.

  20. Thin-film silicon for flexible metal-air batteries.

    PubMed

    Garamoun, Ahmed; Schubert, Markus B; Werner, Jürgen H

    2014-12-01

    Due to its high energy density, theoretical studies propose silicon as a promising candidate material for metal-air batteries. Herein, for the first time, experimental results detail the use of n-type doped amorphous silicon and silicon carbide as fuel in Si-air batteries. Thin-film silicon is particularly interesting for flexible and rolled batteries with high specific energies. Our Si-air batteries exhibit a specific capacity of 269 Ah kg(-1) and an average cell voltage of 0.85 V at a discharge current density of 7.9 μA cm(-2) , corresponding to a specific energy of 229 Wh kg(-1) . Favorably in terms of safety, low concentrated alkaline solution serves as electrolyte. Discharging of the Si-air cells continues as long as there is silicon available for oxidation. PMID:25251223

  1. Overview and Challenges of Thin Film Solar Electric Technologies

    SciTech Connect

    Ullal, H. S.

    2008-12-01

    In this paper, we report on the significant progress made worldwide by thin-film solar cells, namely, amorphous silicon (a-Si), cadmium telluride (CdTe), and copper indium gallium diselenide (CIGS). Thin-film photovoltaic (PV) technology status is also discussed in detail. In addition, R&D and technology challenges in all three areas are elucidated. The worldwide estimated projection for thin-film PV technology production capacity announcements are estimated at more than 5000 MW by 2010.

  2. Selectivity of Direct Methanol Fuel Cell Membranes.

    PubMed

    Aricò, Antonino S; Sebastian, David; Schuster, Michael; Bauer, Bernd; D'Urso, Claudia; Lufrano, Francesco; Baglio, Vincenzo

    2015-11-24

    Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion(®) were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate-PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA) was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC). The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA) was higher than the benchmark Nafion(®) 115-based MEA (77 mW·cm(-2) vs. 64 mW·cm(-2)). This result was due to a lower methanol crossover (47 mA·cm(-2) equivalent current density for s-PEEK vs. 120 mA·cm(-2) for Nafion(®) 115 at 60 °C as recorded at OCV with 2 M methanol) and a suitable area specific resistance (0.15 Ohm cm² for s-PEEK vs. 0.22 Ohm cm² for Nafion(®) 115).

  3. Selectivity of Direct Methanol Fuel Cell Membranes

    PubMed Central

    Aricò, Antonino S.; Sebastian, David; Schuster, Michael; Bauer, Bernd; D’Urso, Claudia; Lufrano, Francesco; Baglio, Vincenzo

    2015-01-01

    Sulfonic acid-functionalized polymer electrolyte membranes alternative to Nafion® were developed. These were hydrocarbon systems, such as blend sulfonated polyetheretherketone (s-PEEK), new generation perfluorosulfonic acid (PFSA) systems, and composite zirconium phosphate–PFSA polymers. The membranes varied in terms of composition, equivalent weight, thickness, and filler and were investigated with regard to their methanol permeation characteristics and proton conductivity for application in direct methanol fuel cells. The behavior of the membrane electrode assemblies (MEA) was investigated in fuel cell with the aim to individuate a correlation between membrane characteristics and their performance in a direct methanol fuel cell (DMFC). The power density of the DMFC at 60 °C increased according to a square root-like function of the membrane selectivity. This was defined as the reciprocal of the product between area specific resistance and crossover. The power density achieved at 60 °C for the most promising s-PEEK-based membrane-electrode assembly (MEA) was higher than the benchmark Nafion® 115-based MEA (77 mW·cm−2 vs. 64 mW·cm−2). This result was due to a lower methanol crossover (47 mA·cm−2 equivalent current density for s-PEEK vs. 120 mA·cm−2 for Nafion® 115 at 60 °C as recorded at OCV with 2 M methanol) and a suitable area specific resistance (0.15 Ohm cm2 for s-PEEK vs. 0.22 Ohm cm2 for Nafion® 115). PMID:26610582

  4. Sputter-deposited fuel cell membranes and electrodes

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Chun, William (Inventor); Ruiz, Ron P. (Inventor); Valdez, Thomas I. (Inventor)

    2001-01-01

    A method for preparing a membrane for use in a fuel cell membrane electrode assembly includes the steps of providing an electrolyte membrane, and sputter-depositing a catalyst onto the electrolyte membrane. The sputter-deposited catalyst may be applied to multiple sides of the electrolyte membrane. A method for forming an electrode for use in a fuel cell membrane electrode assembly includes the steps of obtaining a catalyst, obtaining a backing, and sputter-depositing the catalyst onto the backing. The membranes and electrodes are useful for assembling fuel cells that include an anode electrode, a cathode electrode, a fuel supply, and an electrolyte membrane, wherein the electrolyte membrane includes a sputter-deposited catalyst, and the sputter-deposited catalyst is effective for sustaining a voltage across a membrane electrode assembly in the fuel cell.

  5. Uncooled thin film pyroelectric IR detector with aerogel thermal isolation

    DOEpatents

    Ruffner, Judith A.; Bullington, Jeff A.; Clem, Paul G.; Warren, William L.; Brinker, C. Jeffrey; Tuttle, Bruce A.; Schwartz, Robert W.

    1999-01-01

    A monolithic infrared detector structure which allows integration of pyroelectric thin films atop low thermal conductivity aerogel thin films. The structure comprises, from bottom to top, a substrate, an aerogel insulating layer, a lower electrode, a pyroelectric layer, and an upper electrode layer capped by a blacking layer. The aerogel can offer thermal conductivity less than that of air, while providing a much stronger monolithic alternative to cantilevered or suspended air-gap structures for pyroelectric thin film pixel arrays. Pb(Zr.sub.0.4 Ti.sub.0.6)O.sub.3 thin films deposited on these structures displayed viable pyroelectric properties, while processed at 550.degree. C.

  6. Thin-Film Photovoltaics: Status and Applications to Space Power

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Hepp, Aloysius F.

    1991-01-01

    The potential applications of thin film polycrystalline and amorphous cells for space are discussed. There have been great advances in thin film solar cells for terrestrial applications; transfer of this technology to space applications could result in ultra low weight solar arrays with potentially large gains in specific power. Recent advances in thin film solar cells are reviewed, including polycrystalline copper iridium selenide and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon alloys. The possibility of thin film multi bandgap cascade solar cells is discussed.

  7. Applications of thin-film photovoltaics for space

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Hepp, Aloysius F.

    1991-01-01

    The authors discuss the potential applications of thin-film polycrystalline and amorphous cells for space. There have been great advances in thin-film solar cells for terrestrial applications. Transfer of this technology to space applications could result in ultra low-weight solar arrays with potentially large gains in specific power. Recent advances in thin-film solar cells are reviewed, including polycrystalline copper indium selenide and related I-III-VI2 compounds, polycrystalline cadmium telluride and related II-VI compounds, and amorphous silicon arrays. The possibility of using thin-film multi-bandgap cascade solar cells is discussed.

  8. Dye-Sensitization Of Nanocrystalline ZnO Thin Films

    SciTech Connect

    Ajimsha, R. S.; Tyagi, M.; Das, A. K.; Misra, P.; Kukreja, L. M.

    2010-12-01

    Nannocrystalline and nanoporus thin films of ZnO were synthesized on glass substrates by using wet chemical drop casting method. X-ray diffraction measurements on these samples confirmed the formation of ZnO nanocrystallites in hexagonal wurtzite phase with mean size of {approx}20 nm. Photo sensitization of these nanostructured ZnO thin films was carried out using three types of dyes Rhodamine 6 G, Chlorophyll and cocktail of Rhodamine 6 G and Chlorophyll in 1:1 ratio. Dye sensitized ZnO thin films showed enhanced optical absorption in visible spectral region compared to the pristine ZnO thin films.

  9. Rechargeable thin film battery and method for making the same

    DOEpatents

    Goldner, Ronald B.; Liu, Te-Yang; Goldner, Mark A.; Gerouki, Alexandra; Haas, Terry E.

    2006-01-03

    A rechargeable, stackable, thin film, solid-state lithium electrochemical cell, thin film lithium battery and method for making the same is disclosed. The cell and battery provide for a variety configurations, voltage and current capacities. An innovative low temperature ion beam assisted deposition method for fabricating thin film, solid-state anodes, cathodes and electrolytes is disclosed wherein a source of energetic ions and evaporants combine to form thin film cell components having preferred crystallinity, structure and orientation. The disclosed batteries are particularly useful as power sources for portable electronic devices and electric vehicle applications where high energy density, high reversible charge capacity, high discharge current and long battery lifetimes are required.

  10. Structural characterization of impurified zinc oxide thin films

    SciTech Connect

    Trinca, L. M.; Galca, A. C. Stancu, V. Chirila, C. Pintilie, L.

    2014-11-05

    Europium doped zinc oxide (Eu:ZnO) thin films have been obtained by pulsed laser deposition (PLD). 002 textured thin films were achieved on glass and silicon substrates, while hetero-epilayers and homo-epilayers have been attained on single crystal SrTiO{sub 3} and ZnO, respectively. X-ray Diffraction (XRD) was employed to characterize the Eu:ZnO thin films. Extended XRD studies confirmed the different thin film structural properties as function of chosen substrates.

  11. Processing of magnetostrictive thin film devices

    NASA Astrophysics Data System (ADS)

    Loveless, Michael Ray

    (Tb,Dy)Fesb2 intermetallic alloys exhibit very large magnetostrictive strains. Alloys with composition near Tbsb{0.3}Dysb{0.7}Fesb2, known as Terfenol-D, are of particular interest because this is the composition where room temperature anisotropy compensation occurs and the moment can be easily rotated. Terfenol-D has a cubic Laves phase structure and exhibits maximum magnetostrictive strain along $ directions at room temperature. Bulk Terfenol-D tends to grow as twinned dendritic sheets with $ orientation. Recently, there has been increased interest in Terfenol-D thin film devices. Crystallographic texture can change the magnetostrictive properties of thin films. It is the purpose of this research to study the effect of postdeposition annealing and magnetic annealing treatments on the microstructure of Terfenol-D thin films. It is predicted that textured films can be obtained by exploiting increased magnetocrystalline anisotropy at elevated temperatures. This would improve the low field magnetostrictive strains attainable for device applications. Also of recent interest is the fabrication of magnetostrictive composites. Increased toughness and durability are attainable at the cost of reduced magnetostrictive performance. Terfenol-D composites have been made with polymers. Composites with metals would be stronger and tougher but conventional high temperature processing routes cause unwanted reactions. Temperatures high enough to allow appreciable diffusion for sintering would also allow the metal binder phase to interdiffuse with Terfenol-D. This work also examines the feasibility of explosive compaction of Terfenol-D-metal composites. The short duration, on the order of microseconds, of the pressure and temperature pulse experienced by the powder leads to compaction at near room temperature. This is expected to prevent unwanted reactions between Terfenol-D and the metal binder.

  12. Multi-block copolymers in thin films.

    NASA Astrophysics Data System (ADS)

    Maniadis, Panagiotis; Kober, Edward; Lookman, Turab

    2008-03-01

    We study the behavior of an ABn multi-block copolymer confined to a thin film, using self consistent field theory (SCFT) methods. Due to the breaking of symmetry in the direction of confinement, the propagators do not obey the usual diffusion equation. We derive the diffusion equation which correctly describes the confined polymer system and find that it differs from the original in an area which is approximately 3 times the Kuhn length of the polymer, close to the surface of the film. We use the modified diffusion equation to study the structure of the confined polymer.

  13. Effective dynamics for ferromagnetic thin films

    SciTech Connect

    Garcia-Cervera, Carlos J.; E, Weinan

    2001-07-01

    In a ferromagnetic material, the dynamics of the relaxation process are affected by the presence of a strong shape or material anisotropy. In this article, we systematically explore this fact to derive the effective dynamical equation for a soft ferromagnetic thin film. We show that, as a consequence of the interplay between shape anisotropy and damping, the gyromagnetic term is effectively also a damping term for the in-plane components of the magnetization distribution. We validate our result through numerical simulation of the original Landau{endash}Lifshitz equation and our effective equation. {copyright} 2001 American Institute of Physics.

  14. Ferroelectric Thin Films for Electronic Applications

    NASA Astrophysics Data System (ADS)

    Udayakumar, K. R.

    This study yokes together the feasibility of a family of PbO-based perovskite-structured ferroelectric thin films as functional elements in nonvolatile random access memories (NVRAMs), in high capacity dynamic RAMs, and in a new class of flexure wave piezoelectric ultrasonic micromotors. The dielectric and ferroelectric properties of lead zirconate titanate (PZT) thin films were dependent on thickness; at saturation, the films were characterized by a relative permittivity of 1300, remanent polarization of 36 muC/cm^2 and breakdown strength of over 1 MV/cm. The temperature dependence of permittivity revealed an anomalous behavior with the film annealing temperature. Based on the ferroelectric properties in the bulk, thin films in the lead zirconate -lead zinc niobate (PZ-PZN) solid solution system at 8-12% PZN, examined as alternate compositions for ferroelectric memories, feature switched charges of 4-14 mu C/cm^2, with coercive and saturation voltages less than the semiconductor operating voltage of 5 V. Rapid thermally annealed lead magnesium niobate titanate films were privy to weak signal dielectric permittivity of 2900, remanent polarization of 11 muC/cm^2, and a storage density of 210 fC/mum^2 at 5 V; the films merit consideration for potential applications in ultra large scale integrated circuits as also ferroelectric nonvolatile RAMs. The high breakdown strength and relative permittivity of the PZT films entail maximum stored energy density 10^3 times larger than a silicon electrostatic motor. The longitudinal piezoelectric strain coefficient d_{33 } was measured to be 220 pC/N at a dc bias of 75 kV/cm. The transverse piezoelectric strain coefficient d_{31} bore a nonlinear relationship with the electric field; at 200 kV/cm, d _{31} was -88 pC/N. The development of the piezoelectric ultrasonic micromotors from the PZT thin films, and the architecture of the stator structures are described. Nonoptimized prototype micromotors show rotational velocities of 100

  15. Study of iron mononitride thin films

    SciTech Connect

    Tayal, Akhil Gupta, Mukul Phase, D. M. Reddy, V. R. Gupta, Ajay

    2014-04-24

    In this work we have studied the crystal structural and local ordering of iron and nitrogen in iron mononitride thin films prepared using dc magnetron sputtering at sputtering power of 100W and 500W. The films were sputtered using pure nitrogen to enhance the reactivity of nitrogen with iron. The x-ray diffraction (XRD), conversion electron Mössbauer spectroscopy (CEMS) and soft x-ray absorption spectroscopy (SXAS) studies shows that the film crystallizes in ZnS-type crystal structure.

  16. Thin film photovoltaic device with multilayer substrate

    DOEpatents

    Catalano, Anthony W.; Bhushan, Manjul

    1984-01-01

    A thin film photovoltaic device which utilizes at least one compound semiconductor layer chosen from Groups IIB and VA of the Periodic Table is formed on a multilayer substrate The substrate includes a lowermost support layer on which all of the other layers of the device are formed. Additionally, an uppermost carbide or silicon layer is adjacent to the semiconductor layer. Below the carbide or silicon layer is a metal layer of high conductivity and expansion coefficient equal to or slightly greater than that of the semiconductor layer.

  17. Polydiacetylene thin films for nonlinear optical applications

    NASA Technical Reports Server (NTRS)

    Paley, Mark S.

    1993-01-01

    One very promising class of organic compounds for nonlinear optical (NLO) applications are polydiacetylenes, which are novel in that they are highly conjugated polymers which can also be crystalline. Polydiacetylenes offer several advantages over other organic materials: because of their highly conjugated electronic structures, they are capable of possessing large optical nonlinearities with fast response times; because they are crystalline, they can be highly ordered, which is essential for optimizing their NLO properties; and, last, because they are polymeric, they can be formed as thin films, which are useful for device fabrication. We have actively been carrying out ground-based research on several compounds of interest.

  18. Thin film dielectric microstrip kinetic inductance detectors

    NASA Astrophysics Data System (ADS)

    Mazin, Benjamin A.; Sank, Daniel; McHugh, Sean; Lucero, Erik A.; Merrill, Andrew; Gao, Jiansong; Pappas, David; Moore, David; Zmuidzinas, Jonas

    2010-03-01

    Microwave kinetic inductance detectors, or MKIDs, are a type of low temperature detector that exhibit intrinsic frequency domain multiplexing at microwave frequencies. We present the first theory and measurements on a MKID based on a microstrip transmission line resonator. A complete characterization of the dielectric loss and noise properties of these resonators is performed, and agrees well with the derived theory. A competitive noise equivalent power of 5×10-17 W Hz-1/2 at 10 Hz has been demonstrated. The resonators exhibit the highest quality factors known in a microstrip resonator with a deposited thin film dielectric.

  19. Thin-Film Photovoltaic Device Fabrication

    NASA Technical Reports Server (NTRS)

    Scofield, John H.

    2003-01-01

    This project will primarily involve the fabrication and characterization of thin films and devices for photovoltaic applications. The materials involved include Il-VI materials such as zinc oxide, cadmium sulfide, and doped analogs. The equipment ot be used will be sputtering and physical evaporations. The types of characterization includes electrical, XRD, SEM and CV and related measurements to establish the efficiency of the devices. The faculty fellow will be involved in a research team composed of NASA and University researchers as well as students and other junior researchers.

  20. Performance and Durability of Thin Film Thermocouple Array on a Porous Electrode.

    PubMed

    Guk, Erdogan; Ranaweera, Manoj; Venkatesan, Vijay; Kim, Jung-Sik

    2016-01-01

    Management of solid oxide fuel cell (SOFC) thermal gradients is vital to limit thermal expansion mismatch and thermal stress. However, owing to harsh operation conditions of SOFCs and limited available space in stack configuration, the number of techniques available to obtain temperature distribution from the cell surface is limited. The authors previously developed and studied a thermocouple array pattern to detect surface temperature distribution on an SOFC in open circuit conditions. In this study, the performance in terms of mechanical durability and oxidation state of the thin film thermoelements of the thermocouple array on the porous SOFC cathode is investigated. A thin-film multi-junction thermocouple array was sputter deposited using a magnetron sputter coater. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterisation techniques were carried out to understand characteristics of the thin film before and after temperature (20 °C-800 °C) measurement. Temperature readings from the sensor agreed well with the closely placed commercial thermocouple during heating segments. However, a sensor failure occurred at around 350 °C during the cooling segment. The SEM and XPS tests revealed cracks on the thin film thermoelements and oxidation to the film thickness direction.

  1. Performance and Durability of Thin Film Thermocouple Array on a Porous Electrode

    PubMed Central

    Guk, Erdogan; Ranaweera, Manoj; Venkatesan, Vijay; Kim, Jung-Sik

    2016-01-01

    Management of solid oxide fuel cell (SOFC) thermal gradients is vital to limit thermal expansion mismatch and thermal stress. However, owing to harsh operation conditions of SOFCs and limited available space in stack configuration, the number of techniques available to obtain temperature distribution from the cell surface is limited. The authors previously developed and studied a thermocouple array pattern to detect surface temperature distribution on an SOFC in open circuit conditions. In this study, the performance in terms of mechanical durability and oxidation state of the thin film thermoelements of the thermocouple array on the porous SOFC cathode is investigated. A thin-film multi-junction thermocouple array was sputter deposited using a magnetron sputter coater. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterisation techniques were carried out to understand characteristics of the thin film before and after temperature (20 °C–800 °C) measurement. Temperature readings from the sensor agreed well with the closely placed commercial thermocouple during heating segments. However, a sensor failure occurred at around 350 °C during the cooling segment. The SEM and XPS tests revealed cracks on the thin film thermoelements and oxidation to the film thickness direction. PMID:27563893

  2. Performance and Durability of Thin Film Thermocouple Array on a Porous Electrode.

    PubMed

    Guk, Erdogan; Ranaweera, Manoj; Venkatesan, Vijay; Kim, Jung-Sik

    2016-01-01

    Management of solid oxide fuel cell (SOFC) thermal gradients is vital to limit thermal expansion mismatch and thermal stress. However, owing to harsh operation conditions of SOFCs and limited available space in stack configuration, the number of techniques available to obtain temperature distribution from the cell surface is limited. The authors previously developed and studied a thermocouple array pattern to detect surface temperature distribution on an SOFC in open circuit conditions. In this study, the performance in terms of mechanical durability and oxidation state of the thin film thermoelements of the thermocouple array on the porous SOFC cathode is investigated. A thin-film multi-junction thermocouple array was sputter deposited using a magnetron sputter coater. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterisation techniques were carried out to understand characteristics of the thin film before and after temperature (20 °C-800 °C) measurement. Temperature readings from the sensor agreed well with the closely placed commercial thermocouple during heating segments. However, a sensor failure occurred at around 350 °C during the cooling segment. The SEM and XPS tests revealed cracks on the thin film thermoelements and oxidation to the film thickness direction. PMID:27563893

  3. Lattice-mismatch Strain Effects in Electron-Doped Calcium Manganese Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Hart, Cacie; Yong, Grace; Warecki, Zoey; Chaudhry, Adeel; Sharma, Prakash; Johnson, Anthony; Schaefer, David; Kolagani, Rajeswari

    2015-03-01

    Electron-doped Calcium Manganese Oxide (CaMnO3-δ) thin films are of interest for use as photocatalysts and fuel cell electrodes in renewable energy applications. Oxygen stoichiometry of the films is a key parameter for the functionality in these applications. Currently, we are investigating the properties of (CaMnO3-δ) films grown by pulsed laser deposition. The thin films are epitaxially grown on LaAlO3 and SrTiO3 substrates. Both of these substrates have larger in-plane lattice parameters than CaMnO3-δ, which leads to bi-axial tensile strain in the thin films. We have characterized the thickness dependence of structural, electrical, and morphological properties of these films using high resolution x-ray diffraction, temperature dependent electrical resistivity measurements, and atomic force microscopy. The thickness dependence is characteristically different from what has been preciously observed in thin films of hole-doped manganites. Our results suggest that coupling between tensile strain and oxygen deficiency affect the electrical and structural properties of the material. NSF Grant ECCS1128586.

  4. THE THICKNESS DEPENDENCE OF OXYGEN PERMEABILITY IN SOL-GEL DERIVED CGO-COFE2O4 THIN FILMS ON POROUS CERAMIC SUBSTRATES: A SPUTTERED BLOCKING LAYER FOR THICKNESS CONTROL

    SciTech Connect

    Brinkman, K

    2009-01-08

    Mixed conductive oxides are a topic of interest for applications in oxygen separation membranes as well as use in producing hydrogen fuel through the partial oxidation of methane. The oxygen flux through the membrane is governed both by the oxygen ionic conductivity as well as the material's electronic conductivity; composite membranes like Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} (CGO)-CoFe{sub 2}O{sub 4} (CFO) use gadolinium doped ceria oxides as the ionic conducting material combined with cobalt iron spinel which serves as the electronic conductor. In this study we employ {approx} 50 nm sputtered CeO{sub 2} layers on the surface of porous CGO ceramic substrates which serve as solution 'blocking' layers during the thin film fabrication process facilitating the control of film thickness. Films with thickness of {approx} 2 and 4 microns were prepared by depositing 40 and 95 separate sol-gel layers respectively. Oxygen flux measurements indicated that the permeation increased with decreasing membrane thickness; thin film membrane with thickness on the micron level showed flux values an order of magnitude greater (0.03 {micro}mol/cm{sup 2} s) at 800 C as compared to 1mm thick bulk ceramic membranes (0.003 {micro}mol/cm{sup 2}).

  5. The effect of polymer coatings on switching behavior and cycling durability of Pd/Mg Ni thin films

    NASA Astrophysics Data System (ADS)

    Bao, S.; Yamada, Y.; Okada, M.; Yoshimura, K.

    2007-05-01

    Although Pd-capped Mg-Ni alloy switchable mirror thin films have potential applications in smart windows and optical switches, they degrade quickly and cannot be switched after about 150 cycles. This must be improved for practical use. In this study, we tested several polymer coatings on the surface of Pd/Mg 4Ni switchable mirror thin films as a protective membrane and evaluated the optical switching property and durability. The polymer membrane is able to suppress the oxidization of Mg because it has an excellent gas separation characteristic. Polymer coating extended the switching durability of samples to about 1000 cycles. In addition, the transmittance of the thin film in the transparent state is improved by the coating.

  6. Sol-gel preparation of ion-conducting ceramics for use in thin films

    SciTech Connect

    Steinhauser, M.I.

    1992-12-01

    A metal alkoxide sol-gel solution suitable for depositing a thin film of La{sub 0.6}Sr{sub 0.4}CoO{sub 3} on a porous substrate has been developed; such films should be useful in fuel cell electrode and oxygen separation membrane manufacture. Crack-free films have been deposited on both dense and porous substrates by dip-coating and spin-coating techniques followed by a heat treatment in air. Fourier transform infrared spectroscopy was used to determine the chemical structure of metal alkoxide solution system. X-ray diffraction was used to determine crystalline phases formed at various temperatures, while scanning electron microscopy was used to determine physical characteristics of the films. Surface coatings have been successfully applied to porous substrates through the control of the substrate pore size, deposition parameters, and firing parameters. Conditions have been defined for which films can be deposited, and for which the physical and chemical characteristics of the film can be improved. A theoretical discussion of the chemical reactions taking place before and after hydrolysis in the mixed alkoxide solutions is presented, and the conditions necessary for successful synthesis are defined. Applicability of these films as ionic and electronic conductors is discussed.

  7. Prediction of the force required to unwrap a thin-film origami structure

    NASA Astrophysics Data System (ADS)

    Wilson, Lee; Pellegrino, Sergio

    2015-03-01

    We consider thin film membranes wrapped around a polygonal hub according to the origami crease pattern developed by Guest and Pellegrino. The problem of unwrapping such membranes is important for applications such as space solar sails. Their deployment can be controlled by displacing four edge points radially outwards. During deployment the film buckles multiple times, creating a complex deployment force profile. We have used finite element simulations to investigate how different models of the creases affect the predicted force profile and we have compared the results of our simulations with experimental results for Kapton thin film thicknesses of 50um, 25um, 12.5um and 7.5um. The deployment force profile is also highly dependent on the initial packaged configuration of the film, which in our model is obtained by simulating the folding process from a flat state. This work was supported by NSF Grant No. 1353006.

  8. Fuel cell membrane hydration and fluid metering

    DOEpatents

    Jones, Daniel O.; Walsh, Michael M.

    2003-01-01

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  9. Fuel cell membrane hydration and fluid metering

    DOEpatents

    Jones, Daniel O.; Walsh, Michael M.

    1999-01-01

    A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel in order to mix its respective portion of liquid water with the corresponding portion of the stream. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

  10. Optical thin film metrology for optoelectronics

    NASA Astrophysics Data System (ADS)

    Petrik, Peter

    2012-12-01

    The manufacturing of optoelectronic thin films is of key importance, because it underpins a significant number of industries. The aim of the European joint research project for optoelectronic thin film characterization (IND07) in the European Metrology Research Programme of EURAMET is to develop optical and X-ray metrologies for the assessment of quality as well as key parameters of relevant materials and layer systems. This work is intended to be a step towards the establishment of validated reference metrologies for the reliable characterization, and the development of calibrated reference samples with well-defined and controlled parameters. In a recent comprehensive study (including XPS, AES, GD-OES, GD-MS, SNMS, SIMS, Raman, SE, RBS, ERDA, GIXRD), Abou-Ras et al. (Microscopy and Microanalysis 17 [2011] 728) demonstrated that most characterization techniques have limitations and bottle-necks, and the agreement of the measurement results in terms of accurate, absolute values is not as perfect as one would expect. This paper focuses on optical characterization techniques, laying emphasis on hardware and model development, which determine the kind and number of parameters that can be measured, as well as their accuracy. Some examples will be discussed including optical techniques and materials for photovoltaics, biosensors and waveguides.

  11. Orthogonal Thin Film Photovoltaics on Vertical Nanostructures

    NASA Astrophysics Data System (ADS)

    Ahnood, Arman; Zhou, H.; Suzuki, Y.; Sliz, R.; Fabritius, T.; Nathan, Arokia; Amaratunga, G. A. J.

    2015-12-01

    Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics.

  12. High- Tc thin-film magnetometer

    SciTech Connect

    Miklich, A.H.; Wellstood, F.C.; Kingston, J.J.; Clarke, J. ); Colclough, M.S. ); Cardona, A.H.; Bourne, L.C.; Olson, W.L.; Eddy, M.M. )

    1990-09-01

    We have constructed and tested high-{Tc} magnetometers by coupling a high-{Tc} thin-film Superconducting QUantum Interference Device (SQUID) to two different high-{Tc} thin-film flux transformers. The SQUID was made from Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8+y} films grown on MgO, with junctions consisting of native grain boundaries. The flux transformers were made from YBa{sub 2}Cu{sub 3}O{sub 7-x}, and each had 10-turn input coils and a single-turn pickup loop. The first transformer, which was patterned with a combination of shadow masks and photolithography, yielded a magnetic field gain of about {minus}7.5, functioned up to 79 K, and gave a magnetic field sensitivity B{sub N} (10 Hz) {approx} 3.1 pT Hz{sup {minus}1/2}at 38 K. The second transformer, which was patterned entirely by photolithography, yielded a gain of about {minus}8.7, functioned up to 25 K, and had a sensitivity B{sub N} (10 Hz) {approx} 3.5 pT Hz{sup {minus}1/2} at 4.2 K. In both cases, the limiting noise arose in the SQUID. 10 refs., 5 figs., 1 tab.

  13. PZT Thin Film Piezoelectric Traveling Wave Motor

    NASA Technical Reports Server (NTRS)

    Shen, Dexin; Zhang, Baoan; Yang, Genqing; Jiao, Jiwei; Lu, Jianguo; Wang, Weiyuan

    1995-01-01

    With the development of micro-electro-mechanical systems (MEMS), its various applications are attracting more and more attention. Among MEMS, micro motors, electrostatic and electromagnetic, are the typical and important ones. As an alternative approach, the piezoelectric traveling wave micro motor, based on thin film material and integrated circuit technologies, circumvents many of the drawbacks of the above mentioned two types of motors and displays distinct advantages. In this paper we report on a lead-zirconate-titanate (PZT) piezoelectric thin film traveling wave motor. The PZT film with a thickness of 150 micrometers and a diameter of 8 mm was first deposited onto a metal substrate as the stator material. Then, eight sections were patterned to form the stator electrodes. The rotor had an 8 kHz frequency power supply. The rotation speed of the motor is 100 rpm. The relationship of the friction between the stator and the rotor and the structure of the rotor on rotation were also studied.

  14. Microphase separation of block copolymer thin films.

    PubMed

    Zhang, Jilin; Yu, Xinhong; Yang, Ping; Peng, Juan; Luo, Chunxia; Huang, Weihuan; Han, Yanchun

    2010-04-01

    Today, high-ordered micro- and nano-patterned surfaces are widely used in many areas, such as in the preparation of super-thin dielectric films, photonic crystals, antireflective films, super-non-wetting surfaces, bio-compatible surfaces and microelectric devices. Considering the critical fabrication conditions and the irreducible high cost of the photolithography technique in patterning nano-scale structures (<100 nm), the development of other micro- and nano-patterning techniques that can be used to fabricate long-range ordered features - especially nanoscale arrays - is a promising subject in surface science. In contrast to the traditional photolithography patterning technique, block copolymers can spontaneously phase separate into arrays of periodic patterns with length-scales of 10-50 nm, which provides an efficient pathway to pattern nanoscale features. Today, preparing long-range ordered arrays by block copolymer microphase separation is one of the most promising techniques for the fabrication of nanoscale arrays, not only being a simple process but also having a lower cost than traditional methods. In this feature article, we first summarize the many techniques developed to induce ordering in the microphase separation of the block copolymer thin films. Then, evolution, order-order transitions and reversible switching microdomains are considered, since they are very important in the ordered engineering of microphase separation of the block copolymer thin films. Finally, the outlook of this research area will be given.

  15. Active superconducting devices formed of thin films

    DOEpatents

    Martens, Jon S.; Beyer, James B.; Nordman, James E.; Hohenwarter, Gert K. G.

    1991-05-28

    Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.

  16. Structuring of thin film solar cells

    NASA Astrophysics Data System (ADS)

    Eberhardt, Gabriele; Banse, Henrik; Wagner, Uwe; Peschel, Thomas

    2010-02-01

    Laser structuring of different types of thin film layers is a state of the art process in the photovoltaic industry. TCO layers and molybdenum are structured with e.g. 1064 nm lasers. Amorphous silicon, microcrystalline silicon or cadmium telluride are ablated with 515/532 nm lasers. Typical pulse durations of the lasers in use for these material ablation processes are in the nanosecond range. Up to now the common process for CIS/CIGS cells is needle structuring. Hard metal needles scribe lines with a width of 30 to 60 μm into the semiconductor material. A laser technology would have some advantages compared to mechanical scribing. The precision of the lines would be higher (no chipping effects), the laser has no wear out. The dead area (distance from P1 structuring line to P3 structuring line) can be significantly smaller with the laser technology. So we investigate the structuring of CIS/CIGS materials with ultra short pulse lasers of different wavelengths. The ablation rates and the structuring speeds versus the repetition rates have been established. For the different layer thicknesses and line widths we determined the necessary energy densities. After all tests we can calculate the possible reduction of the dead area on the thin film module. The new technology will result in an increase in the efficiency per module of up to 4 %.

  17. Thin film cadmium telluride photovoltaic cells

    SciTech Connect

    Compaan, A.; Bohn, R. )

    1992-04-01

    This report describes research to develop to vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD) and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl{sub 2}, as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO{sub 2}-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally ({ge} 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater. 19 refs.

  18. Semileaky thin-film optical isolator

    SciTech Connect

    Kirsch, S.T.; Biolsi, W.A.; Blank, S.L.; Tien, P.K.; Martin, R.J.; Bridenbaugh, P.M.; Grabbe, P.

    1981-05-01

    Two interesting effects have been experimentally demonstrated for the first time: (1) simultaneous reciprocal and nonreciprocal mode conversion to achieve an isolation effect and (2) magneto-optic switching between guided and radiation modes. These effects were observed in connection with the construction of a previously proposed thin-film optical isolator. The isolator consists of a piece of LiNbO/sub 3/ placed on top of a thin film of yttrium ion garnet (YIG) with a selenium layer to avoid optical contact problems. The isolator, which is 1 cm long, exhibited 10 dB of isolation at lambda = 1.15 ..mu..m. The observed isolation was better than theoretical predictions and a mysterious isolation direction dependence on mode order was observed. Although the device had 10 dB of insertion loss and required a magnetic field of 40 Oe, with a slight change in wavelength and film composition, it should be possible to reduce the insertion loss and field required to under 1 dB and 0.1 Oe, respectively. These characteristics combined with broad tolerances on film thickness and the length of the isolation region, broadband operation (from lambda = 1.1 to 4.5 ..mu..m), and easy construction and adjustment make the isolator very attractive for use in integrated optics.

  19. Thin film preparation of semiconducting iron pyrite

    NASA Astrophysics Data System (ADS)

    Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

    1990-08-01

    Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

  20. Stripe glasses in ferromagnetic thin films

    NASA Astrophysics Data System (ADS)

    Principi, Alessandro; Katsnelson, Mikhail I.

    2016-02-01

    Domain walls in magnetic multilayered systems can exhibit a very complex and fascinating behavior. For example, the magnetization of thin films of hard magnetic materials is in general perpendicular to the thin-film plane, thanks to the strong out-of-plane anisotropy, but its direction changes periodically, forming an alternating spin-up and spin-down stripe pattern. The latter is stabilized by the competition between the ferromagnetic coupling and dipole-dipole interactions, and disappears when a moderate in-plane magnetic field is applied. It has been suggested that such a behavior may be understood in terms of a self-induced stripe glassiness. In this paper we show that such a scenario is compatible with the experimental findings. The strong out-of-plane magnetic anisotropy of the film is found to be beneficial for the formation of both stripe-ordered and glassy phases. At zero magnetic field the system can form a glass only in a narrow interval of fairly large temperatures. An in-plane magnetic field, however, shifts the glass transition towards lower temperatures, therefore enabling it at or below room temperature. In good qualitative agreement with the experimental findings, we show that a moderate in-plane magnetic field of the order of 50 mT can lead to the formation of defects in the stripe pattern, which sets the onset of the glass transition.

  1. Stripe glasses in ferromagnetic thin films

    NASA Astrophysics Data System (ADS)

    Principi, Alessandro; Katsnelson, Mikhail

    Domain walls in magnetic multilayered systems can exhibit a very complex and fascinating behavior. The magnetization of thin films of hard magnetic materials is in general perpendicular to the thin-film plane, but its direction changes periodically, forming an alternating spin-up and spin-down stripe pattern. The latter is stabilized by the competition between the ferromagnetic coupling and dipole-dipole interactions, and disappears when a moderate in-plane magnetic field is applied. It has been suggested that such a behavior may be understood in terms of a self-induced stripe glassiness. In this paper we show that such a scenario is compatible with the experimental findings. The strong out-of-plane magnetic anisotropy of the film is found to be beneficial for the formation of both the stripe-ordered and glassy phases. At zero magnetic field the system can form a glass only in a narrow interval of fairly large temperatures. An in-plane magnetic field, however, shifts the glass transition towards lower temperatures, therefore enabling it at or below room temperature. In good qualitative agreement with the experimental findings, we show that a moderate in-plane magnetic field of the order of 30 mT can lead to the formation of defects in the stripe pattern.

  2. Antimony selenide thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Zeng, Kai; Xue, Ding-Jiang; Tang, Jiang

    2016-06-01

    Due to their promising applications in low-cost, flexible and high-efficiency photovoltaics, there has been a booming exploration of thin-film solar cells using new absorber materials such as Sb2Se3, SnS, FeS2, CuSbS2 and CuSbSe2. Among them, Sb2Se3-based solar cells are a viable prospect because of their suitable band gap, high absorption coefficient, excellent electronic properties, non-toxicity, low cost, earth-abundant constituents, and intrinsically benign grain boundaries, if suitably oriented. This review surveys the recent development of Sb2Se3-based solar cells with special emphasis on the material and optoelectronic properties of Sb2Se3, the solution-based and vacuum-based fabrication process and the recent progress of Sb2Se3-sensitized and Sb2Se3 thin-film solar cells. A brief overview further addresses some of the future challenges to achieve low-cost, environmentally-friendly and high-efficiency Sb2Se3 solar cells.

  3. Thin Films Characterization by Ultra Trace Metrology

    SciTech Connect

    Danel, A.; Nolot, E.; Decorps, T.; Lardin, T.; Veillerot, M.; Lhostis, S.; Campidelli, Y.; Calvo-Munoz, M.-L.; Kohno, H.; Yamagami, M.

    2007-09-26

    Sensitive and accurate characterization of thin films used in nanoelectronics, thinner than a few nm, represents a challenge for many conventional methods, especially when considering in-line control. With capabilities in the E10 at/cm{sup 2} (<1/10 000 of a mono layer), methods usually dedicated to contamination analysis appear promising, especially TXRF thanks to its non invasive and ease of use aspects, and to its measurement speed and mapping capability. This study shows that the range of linear results from TXRF can be extended to thicknesses of a few nm when using an incident angle higher than the critical angle of the analyzed film. Thus, despite degraded performances in terms of low detection limit, TXRF can provide a direct and very sensitive reading of some critical deposition processes. A dynamic repeatability better than 1% (standard deviation) has been obtained for the control of a 0.6 nm Al{sub 2}O{sub 3} tunnel oxide deposited on a magnetic stack. On the other hand, composition analysis by TXRF, and especially the detection of minor elements into thin films, requires the use of a specific incident angle to optimize sensitivity. Under the best conditions, determination of the composition of Co -based self aligned barriers (CoWP and CoWMoPB films with Co concentration >80%) is done with a precision of 6% on P, 8% on Mo and 13% on W (standard deviation)

  4. Thin film cadmium telluride photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Compaan, A.; Bohn, R.

    1992-04-01

    This report describes research to develop vacuum-based growth techniques for CdTe thin-film solar cells: (1) laser-driven physical vapor deposition (LDPVD), and (2) radio-frequency (rf) sputtering. The LDPVD process was successfully used to deposit thin films of CdS, CdTe, and CdCl(sub 2), as well as related alloys and doped semiconductor materials. The laser-driven deposition process readily permits the use of several target materials in the same vacuum chamber and, thus, complete solar cell structures were fabricated on SnO2-coated glass using LDPVD. The rf sputtering process for film growth became operational, and progress was made in implementing it. Time was also devoted to enhancing or implementing a variety of film characterization systems and device testing facilities. A new system for transient spectroscopy on the ablation plume provided important new information on the physical mechanisms of LDPVD. The measurements show that, e.g., Cd is predominantly in the neutral atomic state in the plume but with a fraction that is highly excited internally (greater than or equal to 6 eV), and that the typical neutral Cd translational kinetic energies perpendicular to the target are 20 eV and greater.

  5. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, B.E.; McLean, W. II

    1996-02-13

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus. 9 figs.

  6. Orthogonal Thin Film Photovoltaics on Vertical Nanostructures.

    PubMed

    Ahnood, Arman; Zhou, H; Suzuki, Y; Sliz, R; Fabritius, T; Nathan, Arokia; Amaratunga, G A J

    2015-12-01

    Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics. PMID:26676997

  7. Orthogonal Thin Film Photovoltaics on Vertical Nanostructures.

    PubMed

    Ahnood, Arman; Zhou, H; Suzuki, Y; Sliz, R; Fabritius, T; Nathan, Arokia; Amaratunga, G A J

    2015-12-01

    Decoupling paths of carrier collection and illumination within photovoltaic devices is one promising approach for improving their efficiency by simultaneously increasing light absorption and carrier collection efficiency. Orthogonal photovoltaic devices are core-shell type structures consisting of thin film photovoltaic stack on vertical nanopillar scaffolds. These types of devices allow charge collection to take place in the radial direction, perpendicular to the path of light in the vertical direction. This approach addresses the inherently high recombination rate of disordered thin films, by allowing semiconductor films with minimal thicknesses to be used in photovoltaic devices, without performance degradation associated with incomplete light absorption. This work considers effects which influence the performance of orthogonal photovoltaic devices. Illumination non-uniformity as light travels across the depth of the pillars, electric field enhancement due to the nanoscale size and shape of the pillars, and series resistance due to the additional surface structure created through the use of pillars are considered. All of these effects influence the operation of orthogonal solar cells and should be considered in the design of vertically nanostructured orthogonal photovoltaics.

  8. Apparatus for laser assisted thin film deposition

    DOEpatents

    Warner, Bruce E.; McLean, II, William

    1996-01-01

    A pulsed laser deposition apparatus uses fiber optics to deliver visible output beams. One or more optical fibers are coupled to one or more laser sources, and delivers visible output beams to a single chamber, to multiple targets in the chamber or to multiple chambers. The laser can run uninterrupted if one of the deposition chambers ceases to operate because other chambers can continue their laser deposition processes. The laser source can be positioned at a remote location relative to the deposition chamber. The use of fiber optics permits multi-plexing. A pulsed visible laser beam is directed at a generally non-perpendicular angle upon the target in the chamber, generating a plume of ions and energetic neutral species. A portion of the plume is deposited on a substrate as a thin film. A pulsed visible output beam with a high pulse repetition frequency is used. The high pulse repetition frequency is greater than 500 Hz, and more preferably, greater than about 1000 Hz. Diamond-like-carbon (DLC) is one of the thin films produced using the apparatus.

  9. Thin-film Rechargeable Lithium Batteries

    DOE R&D Accomplishments Database

    Bates, J. B.; Gruzalski, G. R.; Dudney, N. J.; Luck, C. F.; Yu, X.

    1993-11-01

    Rechargeable thin films batteries with lithium metal anodes, an amorphous inorganic electrolyte, and cathodes of lithium intercalation compounds have been fabricated and characterized. The cathodes include TiS{sub 2}, the {omega} phase of V{sub 2}O{sub 5}, and the cubic spinel Li{sub x}Mn{sub 2}O{sub 4} with open circuit voltages at full charge of about 2.5 V, 3.7 V, and 4.2 V, respectively. The development of these robust cells, which can be cycled thousands of times, was possible because of the stability of the amorphous lithium electrolyte, lithium phosphorus oxynitride. This material has a typical composition of Li{sub 2.9}PO{sub 3.3}N{sub 0.46} and a conductivity at 25 C of 2 {mu}S/cm. Thin film cells have been cycled at 100% depth of discharge using current densities of 2 to 100 {mu}A/cm{sup 2}. The polarization resistance of the cells is due to the slow insertion rate of Li{sup +} ions into the cathode. Chemical diffusion coefficients for Li{sup +} ions in the three types of cathodes have been estimated from the analysis of ac impedance measurements.

  10. Thin-film cadmium telluride solar cells

    NASA Astrophysics Data System (ADS)

    Chu, T. L.

    1986-08-01

    The major objective of this work was to demonstrate CdTe devices grown by chemical vapor deposition (CVD) with a total area greater than 1 cm2 and photovoltic efficiencies of at least 13%. During the period covered, various processing steps were investigated for the preparation of thin-film CdTe heterojunction solar cells of the inverted configuration. Glass coated with fluorine-doped tin oxide was used as the substrate. Thin-film heterojunction solar cells were prepared by depositing p-CdTe films on substrates using CVD and close-spaced sublimation (CSS). Cells prepared from CSS CdTe usually have a higher conversion efficiency than those prepared from CVD CdTe, presumably due to the chemical interaction between CdS and CdTe at the interface during the CVD process. The best cell, about 1.2 sq cm in area, had an AM 1.5 (global) efficiency of 10.5%, and further improvements are expected by optimizing the process parameters.

  11. Hydrothermal epitaxy of perovskite thin films

    NASA Astrophysics Data System (ADS)

    Chien, Allen T.

    1998-12-01

    This work details the discovery and study of a new process for the growth of epitaxial single crystal thin films which we call hydrothermal epitaxy. Hydrothermal epitaxy is a low temperature solution route for producing heteroepitaxial thin films through the use of solution chemistry and structurally similar substrates. The application of this synthesis route has led to the growth of a variety of epitaxial perovskite (BaTiOsb3, SrTiOsb3, and Pb(Zr,Ti)Osb3 (PZT)) thin films which provides a simple processing pathway for the formation of other materials of technological interest. BaTiOsb3 and PZT heteroepitaxial thin films and powders were produced by the hydrothermal method at 90-200sp°C using various alkali bases. XRD and TEM analysis shows that, in each case, the films and powders form epitaxially with a composition nearly identical to that of the starting precursors. Sequential growth experiments show that film formation initiates by the nucleation of submicron faceted islands at the step edges of the SrTiOsb3 substrates followed by coalescence after longer growth periods. A Ba-rich interfacial layer between the BaTiOsb3 islands and the SrTiOsb3 surface is seen by cross-section TEM during early growth periods. Electrophoretic and Basp{2+} adsorption data provide a chemical basis for the existence of the interfacial layer. Homoepitaxial growth of SrTiOsb3 on SrTiOsb3 also occurs by island growth, suggesting that the growth mode may be a consequence of the aqueous surface chemistry inherent in the process. Film formation is shown to be affected by any number of factors including type of base, pH, temperature, and substrate pretreatments. Different cation bases (Na-, K-, Rb-, Cs-, TMA-OH) demonstrated pronounced changes in powder and film morphology. For example, smaller cation bases (e.g., NaOH, KOH and RbOH) resulted the formation of 1.5 mum \\{100\\} faceted perovskite PbTiOsb3 blocks while larger cation bases (e.g., CsOH and TMA-OH) produced 500 nm sized

  12. Vacuum Hold-Down System for Heat-Treating Thin Films

    NASA Technical Reports Server (NTRS)

    Collins, Earl R., Jr.

    1987-01-01

    In improved furnace concept for heat-treating thin films, vacuum ports in vacuum plate(s) hold films connected together in zones so vacuum applied separately to each zone. Allows material being held to shrink or expand while still being held in place. Unclamped zones expand or contract , relieving local stresses so entire sheet accommades thermally induced changes without cracking. Applications include manufacture of thin semiconductor films for solar cells and of membranes for electrolytic production of oxygen.

  13. Eutectic bonds on wafer scale by thin film multilayers

    NASA Astrophysics Data System (ADS)

    Christensen, Carsten; Bouwstra, Siebe

    1996-09-01

    The use of gold based thin film multilayer systems for forming eutectic bonds on wafer scale is investigated and preliminary results will be presented. On polished 4 inch wafers different multilayer systems are developed using thin film techniques and bonded afterwards under reactive atmospheres and different bonding temperatures and forces. Pull tests are performed to extract the bonding strengths.

  14. Progress in polycrystalline thin-film solar cells

    SciTech Connect

    Zweibel, K; Hermann, A; Mitchell, R

    1983-07-01

    Photovoltaic devices based on several polycrystalline thin-film materials have reached near and above 10% sunlight-to-electricity conversion efficiencies. This paper examines the various polycrystalline thin-film PV materials including CuInSe/sub 2/ and CdTe in terms of their material properties, fabrication techniques, problems, and potentials.

  15. Tools to Synthesize the Learning of Thin Films

    ERIC Educational Resources Information Center

    Rojas, Roberto; Fuster, Gonzalo; Slusarenko, Viktor

    2011-01-01

    After a review of textbooks written for undergraduate courses in physics, we have found that discussions on thin films are mostly incomplete. They consider the reflected and not the transmitted light for two instead of the four types of thin films. In this work, we complement the discussion in elementary textbooks, by analysing the phase…

  16. Electrolyte and Electrode Passivation for Thin Film Batteries

    NASA Technical Reports Server (NTRS)

    West, W.; Whitacre, J.; Ratnakumar, B.; Brandon, E.; Blosiu, J.; Surampudi, S.

    2000-01-01

    Passivation films for thin film batteries have been prepared and the conductivity and voltage stability window have been measured. Thin films of Li2CO3 have a large voltage stability window of 4.8V, which facilitates the use of this film as a passivation at both the lithium anode-electrolyte interface at high cathodic potentials.

  17. Applications of Thin Film Thermocouples for Surface Temperature Measurement

    NASA Technical Reports Server (NTRS)

    Martin, Lisa C.; Holanda, Raymond

    1994-01-01

    Thin film thermocouples provide a minimally intrusive means of measuring surface temperature in hostile, high temperature environments. Unlike wire thermocouples, thin films do not necessitate any machining of the surface, therefore leaving intact its structural integrity. Thin films are many orders of magnitude thinner than wire, resulting in less disruption to the gas flow and thermal patterns that exist in the operating environment. Thin film thermocouples have been developed for surface temperature measurement on a variety of engine materials. The sensors are fabricated in the NASA Lewis Research Center's Thin Film Sensor Lab, which is a class 1000 clean room. The thermocouples are platinum-13 percent rhodium versus platinum and are fabricated by the sputtering process. Thin film-to-leadwire connections are made using the parallel-gap welding process. Thermocouples have been developed for use on superalloys, ceramics and ceramic composites, and intermetallics. Some applications of thin film thermocouples are: temperature measurement of space shuttle main engine turbine blade materials, temperature measurement in gas turbine engine testing of advanced materials, and temperature and heat flux measurements in a diesel engine. Fabrication of thin film thermocouples is described. Sensor durability, drift rate, and maximum temperature capabilities are addressed.

  18. Thin film heater on a thermally isolated microstructure

    NASA Astrophysics Data System (ADS)

    Oh, Seajin; Chu, William; Cahill, Sean

    A microheater was fabricated on a thermally isolated silicon (Si) membrane and its electrical and thermomechanical properties were assessed. The sensor design was adjusted for good thermal isolation and good resistance to thermal shock. The heater was a platinum (Pt) thin-film meandering filament deposited with electron beam evaporation and patterned with lift-off methods. In order to operate the heater at high temperatures with minimum loss of Pt by evaporation, the heater was encapsulated with a ceramic film. During the heater operation, most of the heat was dissipated via conduction through the Si membrane which supported the multi-layered heater. When the Si membrane was completely etched away to suspend the heater, the power needed to heat the filament to strong incandescence (about 700 - 800 C) was 110 mW. Structural failure was not observed when the device was subjected to thermocycling up to approximately 500 C. The importance of the thermomechanical match of layers in a multi-layered heater structure, especially for use at high temperatures, is addressed.

  19. Robust, high temperature-ceramic membranes for gas separation

    SciTech Connect

    Berchtold, Kathryn A.; Young, Jennifer S.

    2014-07-29

    A method of making ceramic membranes, and the ceramic membranes so formed, comprising combining a ceramic precursor with an organic or inorganic comonomer, forming the combination as a thin film on a substrate, photopolymerizing the thin film, and pyrolyzing the photopolymerized thin film.

  20. Development of Thin-Film Battery Powered Transdermal Medical Devices

    SciTech Connect

    Bates, J.B.; Sein, T.

    1999-07-06

    Research carried out at ORNL has led to the development of solid state thin-film rechargeable lithium and lithium-ion batteries. These unique devices can be fabricated in a variety of shapes and to any required size, large or small, on virtually any type of substrate. Because they have high energies per unit of volume and mass and because they are rechargeable, thin-film lithium batteries have potentially many applications as small power supplies in consumer and special electronic products. Initially, the objective of this project was to develop thin-film battery powered products. Initially, the objective of this project was to develop thin-film battery powered transdermal electrodes for recording electrocardiograms and electroencephalograms. These ''active'' electrode would eliminate the effect of interference and improve the reliability in diagnosing heart or brain malfunctions. Work in the second phase of this project was directed at the development of thin-film battery powered implantable defibrillators.

  1. Microstructural evolution during stress relaxation of gold thin films

    NASA Astrophysics Data System (ADS)

    Syarbaini, Luthfia Amra

    Microstructure evolution in metal thin films for use in microelectronic devices was studied due to the formation of defects such as whiskers and hillocks that may cause problems in electrical circuits. Thin film stress relaxation can occur through a variety of processes. Understanding such mechanisms and the conditions under which certain mechanism dominate can potentially lead to the improved control of thin film stability. Studies of the 3D microstructural changes in Au thin films on silicon and other substrates with different thermal expansion coefficients aid us in understanding thin film relaxation phenomena such as hillock/whisker formation. Techniques such as in-situ scanning electron microscopy (SEM) heating and cooling experiments, electron backscattered diffraction (EBSD), focus ion beam (FIB) cross sections and atomic force microscopy (AFM) enabled us to quantify the kinetic relationships between relaxation mechanisms and local morphological changes.

  2. Tailoring Thin Film-Lacquer Coatings for Space Application

    NASA Technical Reports Server (NTRS)

    Peters, Wanda C.; Harris, George; Miller, Grace; Petro, John

    1998-01-01

    Thin film coatings have the capability of obtaining a wide range of thermal radiative properties, but the development of thin film coatings can sometimes be difficult and costly when trying to achieve highly specular surfaces. Given any space mission's thermal control requirements, there is often a need for a variation of solar absorptance (Alpha(s)), emittance (epsilon) and/or highly specular surfaces. The utilization of thin film coatings is one process of choice for meeting challenging thermal control requirements because of its ability to provide a wide variety of Alpha(s)/epsilon ratios. Thin film coatings' radiative properties can be tailored to meet specific thermal control requirements through the use of different metals and the variation of dielectric layer thickness. Surface coatings can be spectrally selective to enhance radiative coupling and decoupling. The application of lacquer to a surface can also provide suitable specularity for thin film application without the cost and difficulty associated with polishing.

  3. Thin Films of Quasicrystals: Optical, Electronic, and Mechanical Properties

    NASA Astrophysics Data System (ADS)

    Symko, Orest G.

    1998-03-01

    In order to extend some of the unusual properties of quasicrystals toward practical applications and to study fundamental aspects of these properties, we have developed a technology for the deposition of high quality thin films of quasicrystals on a variety of substrates. Mechanical support for the thin films is provided by the substrate as bulk quasicrystals are brittle. We have applied the thin films to studies of their optical, electrical, and mechanical properties as well as to coatings of biomedical devices. An important characteristic of a quasicrystal is its pseudogap in the electronic density of states; it is determined directly from optical transmission measurements. Optical and mechanical characteristics of the thin films provide strong support for the cluster nature of quasicrystals and emphasize their importance for coatings. When used in biomedical devices, thin film quasicrystalline coatings show remarkable strength, low friction, and non-stick behavior. This work was in collaboration with W. Park, E. Abdel-Rahman, and T. Klein.

  4. Characterization of reliability of printed indium tin oxide thin films.

    PubMed

    Hong, Sung-Jei; Kim, Jong-Woong; Jung, Seung-Boo

    2013-11-01

    Recently, decreasing the amount of indium (In) element in the indium tin oxide (ITO) used for transparent conductive oxide (TCO) thin film has become necessary for cost reduction. One possible approach to this problem is using printed ITO thin film instead of sputtered. Previous studies showed potential for printed ITO thin films as the TCO layer. However, nothing has been reported on the reliability of printed ITO thin films. Therefore, in this study, the reliability of printed ITO thin films was characterized. ITO nanoparticle ink was fabricated and printed onto a glass substrate followed by heating at 400 degrees C. After measurement of the initial values of sheet resistance and optical transmittance of the printed ITO thin films, their reliabilities were characterized with an isothermal-isohumidity test for 500 hours at 85 degrees C and 85% RH, a thermal shock test for 1,000 cycles between 125 degrees C and -40 degrees C, and a high temperature storage test for 500 hours at 125 degrees C. The same properties were investigated after the tests. Printed ITO thin films showed stable properties despite extremely thermal and humid conditions. Sheet resistances of the printed ITO thin films changed slightly from 435 omega/square to 735 omega/square 507 omega/square and 442 omega/square after the tests, respectively. Optical transmittances of the printed ITO thin films were slightly changed from 84.74% to 81.86%, 88.03% and 88.26% after the tests, respectively. These test results suggest the stability of printed ITO thin film despite extreme environments. PMID:24245331

  5. An overview of thin film nitinol endovascular devices.

    PubMed

    Shayan, Mahdis; Chun, Youngjae

    2015-07-01

    Thin film nitinol has unique mechanical properties (e.g., superelasticity), excellent biocompatibility, and ultra-smooth surface, as well as shape memory behavior. All these features along with its low-profile physical dimension (i.e., a few micrometers thick) make this material an ideal candidate in developing low-profile medical devices (e.g., endovascular devices). Thin film nitinol-based devices can be collapsed and inserted in remarkably smaller diameter catheters for a wide range of catheter-based procedures; therefore, it can be easily delivered through highly tortuous or narrow vascular system. A high-quality thin film nitinol can be fabricated by vacuum sputter deposition technique. Micromachining techniques were used to create micro patterns on the thin film nitinol to provide fenestrations for nutrition and oxygen transport and to increase the device's flexibility for the devices used as thin film nitinol covered stent. In addition, a new surface treatment method has been developed for improving the hemocompatibility of thin film nitinol when it is used as a graft material in endovascular devices. Both in vitro and in vivo test data demonstrated a superior hemocompatibility of the thin film nitinol when compared with commercially available endovascular graft materials such as ePTFE or Dacron polyester. Promising features like these have motivated the development of thin film nitinol as a novel biomaterial for creating endovascular devices such as stent grafts, neurovascular flow diverters, and heart valves. This review focuses on thin film nitinol fabrication processes, mechanical and biological properties of the material, as well as current and potential thin film nitinol medical applications.

  6. Low Voltage MEMS Digital Loudspeaker Array Based on Thin-film PZT Actuators

    NASA Astrophysics Data System (ADS)

    Fanget, S.; Casset, F.; Dejaeger, R.; Maire, F.; Desloges, B.; Deutzer, J.; Morisson, R.; Bohard, Y.; Laroche, B.; Escato, J.; Leclere, Q.

    This paper reports on the development of a Digital Loudspeaker Array (DLA) solution based on Pb(Zr0.52,Ti0.48)O3 (PZT) thin-film actuated membranes. These membranes called speaklets are arranged in a matrix and operate in a binary manner by emitting short pulses of sound pressure. Using the principle of additivity of pressures in the air, it is possible to reconstruct audible sounds. For the first time, electromechanical and acoustic characterizations are reported on a 256-MEMS-membranes DLA. Sounds audible as far as several meters from the loudspeaker have been generated using low voltage (8 V).

  7. Direct Measurement of Oxygen Incorporation into Thin Film Oxides at Room Temperature Upon Ultraviolet Phton Irradiation

    SciTech Connect

    Tsuchiya, Masaru; Shutthanandan, Vaithiyalingam; Engelhard, Mark H.; Ramanathan, Shriram

    2008-12-31

    Minute changes in oxygen concentration in complex oxides even of the order of ~0.001% can significantly influence functional properties ranging from onset of superconductivity to colossal dielectric constant and ferroic response. In this letter, we report on direct experimental measurement of enhanced oxygen incorporation into ultra-thin oxide films at room temperature under gentle UV photon exposure. Oxygen concentration changes in nanoscale yttria-doped-zirconia (YDZ) films grown on Ge substrate were quantified using the 16O(d,p)17O nuclear reaction. The oxygen concentration was consistently ~ 3 % larger in UV irradiated YDZ films compared to as-grown YDZ films and can be kinetically controlled. Possible incorporation mechanisms are discussed. This suggests a novel approach to modulate oxygen concentration in complex oxides. There is tremendous interest in the science and applications of ultra-thin oxide films, such as electrolyte membranes for solid oxide fuel cells 1, high-dielectric constant (high-κ) oxides for metal-oxide-semiconductor (MOS) devices 2 and multi-ferroics 3. In addition, thin film oxides also serve as model systems to investigate space charge effects on carrier transport and strongly correlated phenomena such as phase transitions. An overarching problem of central importance is the controlled synthesis of oxide films and how they impact functional properties. Particularly, the role of oxygen vacancies or non-stoichiometry has been found to be crucial in this regard. Examples include large magneto resistance effect and metal-to-insulator transition introduced by reducing oxygen stoichiometry of poly crystalline La0.67Ba0.33MnOz 3, nonsuperconducting-to-superconducting transformation by minute amount of oxygen incorporation upon annealing YBa2Cu3O7-δ(YBCO) films 4, and blue light emission at room temperature in oxygen deficient SrTiO3 (STO) 5, 6. These studies revealed

  8. Amperometric noise at thin film band electrodes.

    PubMed

    Larsen, Simon T; Heien, Michael L; Taboryski, Rafael

    2012-09-18

    Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive polymers and measured the current noise in physiological buffer solution for a wide range of different electrode areas. The noise measurements could be modeled by an analytical expression, representing the electrochemical cell as a resistor and capacitor in series. The studies revealed three domains; for electrodes with low capacitance, the amplifier noise dominated, for electrodes with large capacitances, the noise from the resistance of the electrochemical cell was dominant, while in the intermediate region, the current noise scaled with electrode capacitance. The experimental results and the model presented here can be used for choosing an electrode material and dimensions and when designing chip-based devices for low-noise current measurements. PMID:22928986

  9. Ternary compound thin film solar cells

    NASA Technical Reports Server (NTRS)

    Kazmerski, L. L.

    1975-01-01

    A group of ternary compound semiconductor (I-III-VI2) thin films for future applications in photovoltaic devices is proposed. The consideration of these materials (CuInSe2, CuInTe2 and especially CuInS2) for long range device development is emphasized. Much of the activity to date has been concerned with the growth and properties of CuInX2 films. X-ray and electron diffraction analyses, Hall mobility and coefficient, resistivity and carrier concentration variations with substrate and film temperature as well as grain size data have been determined. Both p- and n-type films of CuInS2 and CuInSe2 have been produced. Single and double source deposition techniques have been utilized. Some data have been recorded for annealed films.

  10. Thin Film Femtosecond Laser Damage Competition

    SciTech Connect

    Stolz, C J; Ristau, D; Turowski, M; Blaschke, H

    2009-11-14

    In order to determine the current status of thin film laser resistance within the private, academic, and government sectors, a damage competition was started at the 2008 Boulder Damage Symposium. This damage competition allows a direct comparison of the current state of the art of high laser resistance coatings since they are tested using the same damage test setup and the same protocol. In 2009 a high reflector coating was selected at a wavelength of 786 nm at normal incidence at a pulse length of 180 femtoseconds. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials and layer count, and spectral results will also be shared.

  11. Structure of Thin-Film Lithium Microbatteries

    NASA Technical Reports Server (NTRS)

    Whitacre, Jay F. (Inventor); Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor)

    2003-01-01

    A process for making thin-film batteries including the steps of cleaning a glass or silicon substrate having an amorphous oxide layer several microns thick; defining with a mask the layer shape when depositing cobalt as an adhesion layer and platinum as a current collector; using the same mask as the preceding step to sputter a layer of LiC(0)O2, on the structure while rocking it back and forth; heating the substrate to 300 C. for 30 minutes; sputtering with a new mask that defines the necessary electrolyte area; evaporating lithium metal anodes using an appropriate shadow mask; and, packaging the cell in a dry-room environment by applying a continuous bead of epoxy around the active cell areas and resting a glass slide over the top thereof. The batteries produced by the above process are disclosed.

  12. Thermal properties of methyltrimethoxysilane aerogel thin films

    NASA Astrophysics Data System (ADS)

    Acquaroli, Leandro N.; Newby, Pascal; Santato, Clara; Peter, Yves-Alain

    2016-10-01

    Aerogels are light and porous solids whose properties, largely determined by their nanostructure, are useful in a wide range of applications, e.g., thermal insulation. In this work, as-deposited and thermally treated air-filled silica aerogel thin films synthesized using the sol-gel method were studied for their thermal properties using the 3-omega technique, at ambient conditions. The thermal conductivity and diffusivity were found to increase as the porosity of the aerogel decreased. Thermally treated films show a clear reduction in thermal conductivity compared with that of as-deposited films, likely due to an increase of porosity. The smallest thermal conductivity and diffusivity found for our aerogels were 0.019 W m-1 K-1 and 9.8 × 10-9 m2 s-1. A model was used to identify the components (solid, gaseous and radiative) of the total thermal conductivity of the aerogel.

  13. Thin film oxygen partial pressure sensor

    NASA Technical Reports Server (NTRS)

    Wortman, J. J.; Harrison, J. W.; Honbarrier, H. L.; Yen, J.

    1972-01-01

    The development is described of a laboratory model oxygen partial pressure sensor using a sputtered zinc oxide thin film. The film is operated at about 400 C through the use of a miniature silicon bar. Because of the unique resistance versus temperature relation of the silicon bar, control of the operational temperature is achieved by controlling the resistance. A circuit for accomplishing this is described. The response of sputtered zinc oxide films of various thicknesses to oxygen, nitrogen, argon, carbon dioxide, and water vapor caused a change in the film resistance. Over a large range, film conductance varied approximately as the square root of the oxygen partial pressure. The presence of water vapor in the gas stream caused a shift in the film conductance at a given oxygen partial pressure. A theoretical model is presented to explain the characteristic features of the zinc oxide response to oxygen.

  14. Mirrorlike pulsed laser deposited tungsten thin film

    SciTech Connect

    Mostako, A. T. T.; Khare, Alika; Rao, C. V. S.

    2011-01-15

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10{sup -5} Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness {approx}782 nm.

  15. Mirrorlike pulsed laser deposited tungsten thin film.

    PubMed

    Mostako, A T T; Rao, C V S; Khare, Alika

    2011-01-01

    Mirrorlike tungsten thin films on stainless steel substrate deposited via pulsed laser deposition technique in vacuum (10(-5) Torr) is reported, which may find direct application as first mirror in fusion devices. The crystal structure of tungsten film is analyzed using x-ray diffraction pattern, surface morphology of the tungsten films is studied with scanning electron microscope and atomic force microscope. The film composition is identified using energy dispersive x-ray. The specular and diffuse reflectivities with respect to stainless steel substrate of the tungsten films are recorded with FTIR spectra. The thickness and the optical quality of pulsed laser deposition deposited films are tested via interferometric technique. The reflectivity is approaching about that of the bulk for the tungsten film of thickness ∼782 nm. PMID:21280810

  16. Modeling of polycrystalline thin film solar cells

    NASA Astrophysics Data System (ADS)

    Fahrenbruch, Alan L.

    1999-03-01

    This paper describes modeling polycrystalline thin-film solar cells using the program AMPS-1D1 to visualize the relationships between the many variables involved. These simulations are steps toward two dimensional modeling the effects of grain boundaries in polycrystalline cells. Although this paper describes results for the CdS/CdTe cell, the ideas presented here are applicable to copper-indium-gallium selenide (CIGS) cells as well as other types of cells. Results of these one-dimensional simulations are presented: (a) the duplication of experimentally observed cell parameters, (b) the effects of back-contact potential barrier height and its relation to stressing the cell, (c) the effects of the depletion layer width in the CdTe layer on cell parameters, and (d) the effects of CdS layer thickness on the cell parameters. Experience using the software is also described.

  17. Rechargeable thin-film electrochemical generator

    DOEpatents

    Rouillard, Roger; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Ranger, Michel; Sudano, Anthony; Trice, Jennifer L.; Turgeon, Thomas A.

    2000-09-15

    An improved electrochemical generator is disclosed. The electrochemical generator includes a thin-film electrochemical cell which is maintained in a state of compression through use of an internal or an external pressure apparatus. A thermal conductor, which is connected to at least one of the positive or negative contacts of the cell, conducts current into and out of the cell and also conducts thermal energy between the cell and thermally conductive, electrically resistive material disposed on a vessel wall adjacent the conductor. The thermally conductive, electrically resistive material may include an anodized coating or a thin sheet of a plastic, mineral-based material or conductive polymer material. The thermal conductor is fabricated to include a resilient portion which expands and contracts to maintain mechanical contact between the cell and the thermally conductive material in the presence of relative movement between the cell and the wall structure. The electrochemical generator may be disposed in a hermetically sealed housing.

  18. Supramolecular structure of electroactive polymer thin films

    NASA Astrophysics Data System (ADS)

    Kornilov, V. M.; Lachinov, A. N.; Karamov, D. D.; Nabiullin, I. R.; Kul'velis, Yu. V.

    2016-05-01

    This paper presents the results of an experimental investigation of the supramolecular structure of polydiphenylenephthalide thin films that exhibit effects of resistive switching. The supramolecular structure of the polymer has been investigated using small-angle neutron scattering in conjunction with atomic force microscopy. It has been found that the internal structure of polymer films consists of structural elements in the form of spheroids. The sizes of the structural elements, which were obtained from the neutron scattering data and analysis of the atomic force microscopy images, correlate well with each other. A model of the formation of polymer layers has been proposed. The observed structural elements in polymer films are formed due to the association of macromolecules in the initial polymer solution.

  19. When are thin films of metals metallic?

    NASA Astrophysics Data System (ADS)

    Plummer, E. W.; Dowben, P. A.

    1993-04-01

    There is an increasing body of experimental information suggesting that very thin films of materials, normally considered to be metals, exhibit behavior characteristic of a nonmetal. In almost all cases, there is a nonmetal-to-metal transition as a function of film density or thickness, frequently accompanied by a structural transition. Amazingly, this behavior seems to occur for metal films on metal substrates, as well as for metals on semiconductors. The identification of this phenomena and the subsequent explanation has been slow in developing, due to the inability to directly measure the conductivity of a submonolayer film. This paper will discuss the evidence accumulated from variety of spectroscopic experimental techniques for three systems: a Mott-Hubbard transition, a Peierls-like distortion, and a Wilson transition.

  20. Organic thin films based sensor applications

    NASA Astrophysics Data System (ADS)

    Jung, Soyoun; Ji, Taeksoo; Varadan, Vijay K.

    2006-03-01

    Organic semiconductors, such as pentacene, are particularly interesting because of its potential for various applications including thin film transistors (TFTs), electronic papers, radio frequency identification cards (RFIDs), and sensors. In this paper, we review recent progress in organic electronics with emphasis on their applications for sensing devices, and investigate the morphologies of pentacene films deposited on SiO II and Si surfaces at different substrate temperatures. Scanning electron microcopy (SEM) micrographs from a nominally 50nm-thick pentacene film on SiO II indicate that the grain sizes of pentacene film increase with an increase in substrate temperature. In addition, the grain size on clean silicon grown at a substrate temperature of 100 degrees C is markedly larger that on SiO II, ranging 10~20μm. Based on this morphological investigation on pentacene films, various types of organic sensors and devices with conjunction with interdigitated, gated and ungated structures are presented.